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Columbia University
1.
Yu, Yue.
Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties.
Degree: 2017, Columbia University
URL: https://doi.org/10.7916/D8FT8Z90 
► The highly optimized hierarchical structure of trabecular bone is a major contributor to its remarkable mechanical properties. At the micro-scale level, individual plate-like and rod-like…
(more)
▼ The highly optimized hierarchical structure of trabecular bone is a major contributor to its remarkable mechanical properties. At the micro-scale level, individual plate-like and rod-like trabeculae are interconnected, forming a complex trabecular architecture. It is widely believed that bone strength, an important mechanical characteristic that describes the capability of bone to resist fracture, is largely determined by the tissue-level material properties of these microscopic trabecular elements. However, due to the complicated microstructure and irregular morphology of trabecular bone, a link between the tissue-level and the apparent level mechanics in trabecular bone has never been established. Thus, the goal of this thesis is to examine the tissue-level material properties of trabecular bone and their contribution to apparent-level bone mechanics, and ultimately to improve our fundamental understanding and assessment of bone strength in diseased and healthy patients.
At the micro-scale level, plate-like and rod-like trabeculae are distinctly aligned along different orientations on the anatomical axis of the skeleton. Also, the highly organized underlying ultrastructure of bone tissue suggests trabecular bone might possess an anisotropic tissue modulus, i.e. different modulus in the axial and lateral cross-section of a trabecula. In this thesis, we studied this tissue-level anisotropy by examining mechanical properties of individual trabecular plates and rods aligned longitudinally, obliquely, and transversely on the anatomical axis using micro-indentation. We discovered that, despite the different orientations of trabeculae, tissue moduli are higher in the axial direction than in the lateral direction for both plates and rods. We also discovered that plates have a higher tissue modulus than rods, suggesting different degrees of mineralization. Furthermore, the tissue mineral density correlated strongly but distinctly with tissue modulus in the axial and lateral directions, providing descriptions on how spatially heterogeneous mineralization at the tissue level affects the tissue modulus.
After characterization of the anisotropic and heterogeneous modulus of trabecular bone at the tissue level, we then sought to investigate its contribution to apparent-level mechanical properties, including apparent Young’s modulus and yield strength. Non-linear FE voxel models incorporating experimentally determined anisotropy and heterogeneity were created from micro-computed tomography (µCT) images of healthy trabecular bone samples. Apparent Young's modulus and yield strength predicted by the models were compared to and correlated with gold standard mechanical testing measurements, as well as to the same FE models without incorporation of anisotropy and/or heterogeneity. We discovered that the anisotropic model prediction was highly correlated and indistinguishable from mechanical testing measurements. However, the prediction power of the model was not enhanced by incorporating anisotropy and…
Subjects/Keywords: Biomedical engineering; Bones – Mechanical properties; Tissues – Mechanical properties; Bones – Diseases
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APA (6th Edition):
Yu, Y. (2017). Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8FT8Z90
Chicago Manual of Style (16th Edition):
Yu, Yue. “Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties.” 2017. Doctoral Dissertation, Columbia University. Accessed January 20, 2021.
https://doi.org/10.7916/D8FT8Z90.
MLA Handbook (7th Edition):
Yu, Yue. “Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties.” 2017. Web. 20 Jan 2021.
Vancouver:
Yu Y. Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties. [Internet] [Doctoral dissertation]. Columbia University; 2017. [cited 2021 Jan 20].
Available from: https://doi.org/10.7916/D8FT8Z90.
Council of Science Editors:
Yu Y. Contributions of anisotropic and heterogeneous tissue modulus to apparent trabecular bone mechanical properties. [Doctoral Dissertation]. Columbia University; 2017. Available from: https://doi.org/10.7916/D8FT8Z90
Ryerson University
2.
Pandya, Aditya.
Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms.
Degree: 2012, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A1299
► Traditional ultrasound imaging monitors the backscattering properties of the object being imaged. Many hybrid imaging techniques such as photo-acoustic imaging, electro-acoustic imaging etc. have been…
(more)
▼ Traditional ultrasound imaging monitors the backscattering
properties of the object being imaged. Many hybrid imaging techniques such as photo-acoustic imaging, electro-acoustic imaging etc. have been developed to enhance the contrast in imaging. The main objective of this study was to monitor the electrically induced
mechanical changes (EIMC) in ultrasound phantoms. Changes in time shifting of the signals and amplitude changes were investigated. Images were formed using a linear array ultrasound probe based on the time-delay estimates and the amplitude changes occurring in the tissue/phantom structure. EIMC in phantoms were found to depend on the applied electric field, gelling agent concentration, and salt concentration. The dependence of EIMC on the various parameters can be explained by the stiffness and fixed charge densities (FCD) of the phantoms. Knowledge gained from experimental results and its future extensions might culminate to form a method to image
tissues based on their electrokinetic
properties.
Advisors/Committee Members: Xu, Yuan (Thesis advisor), Ryerson University (Degree grantor).
Subjects/Keywords: Tissues – Analysis; Electrokinetics; Diagnostic ultrasonic imaging; Tissues – Mechanical properties; Medical physics; Biophysics
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APA (6th Edition):
Pandya, A. (2012). Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A1299
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Pandya, Aditya. “Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms.” 2012. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A1299.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pandya, Aditya. “Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms.” 2012. Web. 20 Jan 2021.
Vancouver:
Pandya A. Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms. [Internet] [Thesis]. Ryerson University; 2012. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1299.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pandya A. Ultrasound mediated study of the electrokinetic effects in biological tissues and phantoms. [Thesis]. Ryerson University; 2012. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1299
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Ryerson University
3.
Sadowski, Radoslaw.
Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy.
Degree: 2012, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A1171
► Laser interstitial thermal therapy (LITT) is a minimally invasive therapy in which light is delivered using optical fibers inserted into tissue to treat malignant tumours.…
(more)
▼ Laser interstitial thermal therapy (LITT) is a minimally invasive therapy in which light is delivered using optical fibers inserted into tissue to treat malignant tumours. Heating tissue above 55°C causes tissue coagulation, creating non-viable tissue. Previous work has demonstrated that radiance measurements are sensitive to heat-induced changes in tissue optical
properties. This study investigates the use of radiance measurements to differentiate permanent temperature-induced changes in optical propagation, which reflect thermal damage, from any transient changes in optical propagation. Experiments in water using our white-light point radiance spectroscopy (PRS) technique demonstrate that PRS is sensitive to detect optical absorption and temperature-dependence in the optical absorption of water, and a change in the acceptance cone with temperature. Experimental results using PRS in heated ex vivo porcine tissue show that the optical signal mainly represents permanent thermal damage and only a small part of the signal represent a temperature-dependent change due to water.
Advisors/Committee Members: Kumaradas, Carl (Thesis advisor), Weersink, Robert (Thesis advisor), Whelan, William (Thesis advisor), Ryerson University (Degree grantor).
Subjects/Keywords: Tissues – Effect of heat on; Lasers in medicine; Tissues – Optical properties; Tissues – Thermal properties; Lasers – Therapeutic use; Medical physics
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APA ·
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MLA ·
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CSE |
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APA (6th Edition):
Sadowski, R. (2012). Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A1171
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sadowski, Radoslaw. “Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy.” 2012. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A1171.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sadowski, Radoslaw. “Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy.” 2012. Web. 20 Jan 2021.
Vancouver:
Sadowski R. Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy. [Internet] [Thesis]. Ryerson University; 2012. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1171.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sadowski R. Measuring the Effects of Temperature on Optical Propagation in Heated Tissues Using Point Radiance Spectroscopy. [Thesis]. Ryerson University; 2012. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1171
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Ryerson University
4.
Doganay, Ozkan.
Monitoring electric field induced changes in biological tissue by using ultrasound.
Degree: 2010, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A1480
► A new effect resulting from the application of an electric field to biomaterials was discovered by analyzing ultrasound echo signals. The new effect was observed…
(more)
▼ A new effect resulting from the application of an electric field to biomaterials was discovered by analyzing ultrasound echo signals. The new effect was observed in ex-vivo biological
tissues such as porcine heart, muscle, fat, and liver and tissue mimicking phantoms for an electric field were on the order of a few Volt/cm. Changes in the arrival time of ultrasound echoes were processed using cross-correlation based algorithms. The gradient of shifting along the ultrasound axis showed a strain in the direction perpendicular to the applied electric field. The electric field also lead to changes in the ultrasound echo amplitude. The amount of the strain and the echo amplitude change depended on the history of the applied electric field. The new effect cannot be explained by resistive heating, piezoelectric effect, or electrostriction. It might be related to the electrokinetic effects.
Advisors/Committee Members: Xu, Yuan (Thesis advisor), Ryerson University (Degree grantor).
Subjects/Keywords: Tissues – Mechanical properties; Biomedical materials – Mechanical properties; Electromagnetism – Physiological effect Ultrasonic imaging; Ultrasonics in biology
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APA ·
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APA (6th Edition):
Doganay, O. (2010). Monitoring electric field induced changes in biological tissue by using ultrasound. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A1480
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Doganay, Ozkan. “Monitoring electric field induced changes in biological tissue by using ultrasound.” 2010. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A1480.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Doganay, Ozkan. “Monitoring electric field induced changes in biological tissue by using ultrasound.” 2010. Web. 20 Jan 2021.
Vancouver:
Doganay O. Monitoring electric field induced changes in biological tissue by using ultrasound. [Internet] [Thesis]. Ryerson University; 2010. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1480.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Doganay O. Monitoring electric field induced changes in biological tissue by using ultrasound. [Thesis]. Ryerson University; 2010. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1480
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
5.
Azote, Somiealo.
Mechanical properties of cells and modelling of structural instabilities in tissues.
Degree: PhD, Physics, 2018, Stellenbosch University
URL: http://hdl.handle.net/10019.1/104963
► ENGLISH ABSTRACT : Cells have inherent mechanical properties that can be modelled physically. Statistical physics approaches permit the understanding of deformation dependence by modelling the…
(more)
▼ ENGLISH ABSTRACT : Cells have inherent mechanical properties that can be modelled physically. Statistical physics
approaches permit the understanding of deformation dependence by modelling the various elements of the cytoskeleton and combining these with the constraints and physical properties
of the cell membrane. When cells combine to form more complex structures, including, for
example, epithelial structures, the resulting structure also needs to be understood. We wish to
understand the mechanical contribution to the elastic properties and stability of the cell within
the tissue when branching actin cytoskeletal network emerge or grow and their structure, spatial organisation and orientational ordering geometrically constrained by the cell membrane.
Based on a grand canonical ensemble formalism by Frisch et al. [1] and Müller-Nedebock
et al. [2], we model the structure of branching actin networks of living cell cytoskeletal filaments when these are rigidly contained with geometrical confining regions. The formalism
allows a thermodynamic equilibrium calculation of density and orientational order density for
fillaments and branch points. We find distinct local orientation, order parameter and density
profiles for network filament segments, as the degree of branching and the ratio of persistence
lengths of the filaments to the confining region size are varied. These results suggest the role
of the confinement in the structural properties and organization of branching actin networks
inside the confining region. We next investigated the contribution of the elastic properties of
the networks to the elastic properties and stability of the cells within tissues by computing the free energies and forces of networks system. We find that tissue cells are stable against
compression while cell under shear become unstable beyond a critical angle.
AFRIKAANSE OPSOMMING : Selle het inherente eienskappe wat met die sika gemodelleer kan word. Statistiese ska benaderingspunte laat toe om die vervormingsafhankliheid te verstaan deur die modellering van
verskillende elemente van die sitoskelet en om dit met die randkondisies en siese eienskape van
die selmembraan te kombineer. Wanneer selle gekombineer word om meer komplekse strukture
te vorm, insluitende, byvoorbeeld, epitele strukture, dan moet die resulterende struktuur ook
ondersoek word. Ons wil die meganiese bydrae tot die elastiese eienskappe en die stabiliteit van
die sel as deel van die weefsel verstaan, wanneer vertakkende aktien netwerke ontstaan en groei,
en hulle struktuur, organisasie in die ruimte deur die geometrie van die sel ingeperk word.
Gebaseer op n grootkanoniese formalisme van Frisch, et al., en van Müller-Nedebock et al.
modelleer ons die struktuur van vertakkende aktien netwerke van dinamiese selle se sitoskelet-
lamente wanneer hierdie tot starre geometriese gebiede beperk word. Die formalisme laat n
berekening in die termodinamiese ewewig toe van die digtheid and orde in uitrigtings vir die
lamente and vertakkingspunte. Ons…
Advisors/Committee Members: Müller-Nedebock, Kristian, Stellenbosch University. Faculty of Science. Dept. of Physics.
Subjects/Keywords: Cytoskeleton; Tissues; Cells – Mathematical models.; Cytoplasmic filaments; Cells – Mechanical properties; UCTD
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APA ·
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Manager
APA (6th Edition):
Azote, S. (2018). Mechanical properties of cells and modelling of structural instabilities in tissues. (Doctoral Dissertation). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/104963
Chicago Manual of Style (16th Edition):
Azote, Somiealo. “Mechanical properties of cells and modelling of structural instabilities in tissues.” 2018. Doctoral Dissertation, Stellenbosch University. Accessed January 20, 2021.
http://hdl.handle.net/10019.1/104963.
MLA Handbook (7th Edition):
Azote, Somiealo. “Mechanical properties of cells and modelling of structural instabilities in tissues.” 2018. Web. 20 Jan 2021.
Vancouver:
Azote S. Mechanical properties of cells and modelling of structural instabilities in tissues. [Internet] [Doctoral dissertation]. Stellenbosch University; 2018. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10019.1/104963.
Council of Science Editors:
Azote S. Mechanical properties of cells and modelling of structural instabilities in tissues. [Doctoral Dissertation]. Stellenbosch University; 2018. Available from: http://hdl.handle.net/10019.1/104963
University of Waterloo
6.
Nafo, Wanis.
Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation.
Degree: 2020, University of Waterloo
URL: http://hdl.handle.net/10012/15727
► The mechanical properties of soft materials are used in a wide range of fields and applications including biomedical engineering, sports, and automobile industry, in addition…
(more)
▼ The mechanical properties of soft materials are used in a wide range of fields and applications including biomedical engineering, sports, and automobile industry, in addition to medical applications. Therefore, several methods have been used to measure these properties including tension, compression, and indentation.
This study focuses on the application of multiaxial loading using cavitation mechanics to measure nonlinear mechanical properties of soft materials. It was found that applying controlled cavitation within the internal structure of soft materials provided enough information to characterize their mechanical behavior. This is done by inserting a needle-balloon tool inside the tested material while being attached to a system that allows for injections of an incompressible fluid (water) into the balloon.
To establish this methodology as a robust characterization technique of the mechanics of soft materials, it was used in a four-stages investigation: developing an analytical framework to characterize the non-linear elastic behavior of rubber-like materials (elastomeric gels), measuring the hyperelastic properties of soft biological tissues (porcine liver), comparing the cavity expansion test with a conventional uniaxial tensile testing, and establishing an analytical framework to characterize the time-dependent behavior of viscoelastic materials.
In the first stage, a solution that relates the applied radial loads and tangential deformation is introduced. This solution allows the calibration of hyperelastic strain energy functions (SEF), which were Yeoh, Arruda-Boyce and Ogden (used in all stages). Finite element simulations were used to validate the material parameters of the three hyperelastic models. Computed tomography (CT) imaging was used to validate the spherical configuration assumption of the inflated balloon inside the sample. The validation process considered the two types of stresses generated during the test, radial and hoop stresses. It was observed that the radial stresses were insignificant compared to the hoop stresses.
In the second stage, a smaller balloon was used to test porcine liver tissues; however, the protocol of this stage was similar to the first stage. Few changes were introduced to the definition of the deformation term, as a result, the measured deformations in the cavity test coincided with the deformation levels reported in literature. In addition, the three hyperelastic models predicted initial shear moduli that agreed with their counterparts reported in literature using conventional testing techniques.
To understand the similarities and differences between the cavity expansion test and conventional axial loading, the third stage addressed the comparison between the cavitation and uniaxial tension characterization. The comparison focused on the stress levels, range of strains as well as the initial shear moduli. It was found that the strain levels in the hydrogels were similar up to the failure point. In addition, the hoop stresses generated due to cavity loads were…
Subjects/Keywords: mechanical characterization; Cavity expansion; hyperelasticity; viscoelasticity; computed tomography; biological tissues; PVA hydrogels; Tissues; Mechanical properties; Cavitation; Elasticity; Tomography; Colloids
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APA ·
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APA (6th Edition):
Nafo, W. (2020). Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/15727
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nafo, Wanis. “Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation.” 2020. Thesis, University of Waterloo. Accessed January 20, 2021.
http://hdl.handle.net/10012/15727.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nafo, Wanis. “Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation.” 2020. Web. 20 Jan 2021.
Vancouver:
Nafo W. Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation. [Internet] [Thesis]. University of Waterloo; 2020. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10012/15727.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nafo W. Mechanical Characterization of Soft Materials Using Volume-Controlled Cavitation. [Thesis]. University of Waterloo; 2020. Available from: http://hdl.handle.net/10012/15727
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Columbia University
7.
Yoshida, Kyoko.
Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling.
Degree: 2016, Columbia University
URL: https://doi.org/10.7916/D87M080Q
► The timely remodeling of the cervix from a mechanical barrier into a soft, compliant structure, which dilates in response to uterine contractions is crucial for…
(more)
▼ The timely remodeling of the cervix from a mechanical barrier into a soft, compliant structure, which dilates in response to uterine contractions is crucial for the safe delivery for a term baby. A cervix which softens too early in the pregnancy is implicated in spontaneous preterm births (sPTB). Currently, 15 million babies are affected by PTB annually, early diagnosis is difficult, and 95% of all PTBs are unmanageable by available therapies. These statistics highlight the need to better understand the biological processes involved in cervical remodeling and its downstream effects on material properties. To address this need, we propose the development of a hormone-mediated material constitutive model for the cervix where steroid hormone actions on key tissue constituents are incorporated into a microstructure-inspired material model.
As the first steps towards the development of this model, the main objective of this dissertation work is to understand the key structure-mechanical function relationships involved in pregnancy. To understand cervical material property changes, the equilibrium swelling and tensile response of the nonpregnant and pregnant mouse cervix is measured, a porous fiber composite material model is proposed, and the model is fit to the mechanical data then validated. To better understand key tissue constituents involved, the evolution of intermolecular collagen crosslinks is determined in normal pregnancy and the role of the small proteoglycan, decorin, and elastic fiber structure on cervical mechanical function is investigated.
The results presented here demonstrate that a porous, continuously distributed fiber composite model captures the three-dimensional mechanical properties of the nonpregnant and pregnant cervix. The material property changes of the cervix in a 19-day mouse gestation is described as a four order of magnitude decrease in the parameter associated with the fiber stiffness. We provide quantitative evidence to demonstrate the role of collagen crosslinks on tissue softening in the first 15 days, but not in the latter stages of a mouse pregnancy. A role of elastic fiber structure on cervical mechanical function is demonstrated, as well as distinct roles of estrogen on elastic fiber structure and progesterone on collagen fibril structure. Lastly, an analysis of the time-dependent response of cervices from nonpregnant, normal pregnant, and induced PTB mice are presented. This dissertation concludes by reviewing the presented data within the context of the proposed framework to suggest future directions towards its development.
Subjects/Keywords: Pregnancy; Tissue remodeling; Materials – Mechanical properties; Tissues – Models; Cervix uteri; Mechanical engineering
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APA ·
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MLA ·
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to Zotero / EndNote / Reference
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APA (6th Edition):
Yoshida, K. (2016). Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D87M080Q
Chicago Manual of Style (16th Edition):
Yoshida, Kyoko. “Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling.” 2016. Doctoral Dissertation, Columbia University. Accessed January 20, 2021.
https://doi.org/10.7916/D87M080Q.
MLA Handbook (7th Edition):
Yoshida, Kyoko. “Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling.” 2016. Web. 20 Jan 2021.
Vancouver:
Yoshida K. Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling. [Internet] [Doctoral dissertation]. Columbia University; 2016. [cited 2021 Jan 20].
Available from: https://doi.org/10.7916/D87M080Q.
Council of Science Editors:
Yoshida K. Characterizing the structure-function relationships of the mouse cervix in pregnancy: Towards the development of a hormone-mediated material model for cervical remodeling. [Doctoral Dissertation]. Columbia University; 2016. Available from: https://doi.org/10.7916/D87M080Q
8.
Brunel, Benjamin.
Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering.
Degree: Docteur es, Physique pour les sciences du vivant, 2018, Université Grenoble Alpes (ComUE)
URL: http://www.theses.fr/2018GREAY047
► Lorsqu'une tumeur grossit, elle exerce une pression sur les tissus environnants et est comprimée en retour. Des expériences sur un modèle de tumeur in vitro,…
(more)
▼ Lorsqu'une tumeur grossit, elle exerce une pression sur les tissus environnants et est comprimée en retour. Des expériences sur un modèle de tumeur in vitro, appelé sphéroïde, ont montré que cette pression influence largement le devenir du tissu cancéreux, notamment en freinant sa croissance, mais aussi en le rendant plus invasif. Pour mieux comprendre ce dernier effet, nous avons cherché à étudier le comportement migratoire des cellules à l'intérieur d'un sphéroïde sous pression. Observer l'intérieur d'un sphéroïde pose cependant un problème technique car les méthodes usuelles d'imagerie ne sont pas utilisables dans des tissus épais (> 100 μm). L'imagerie classique étant limitée en profondeur à cause de la diffusion de la lumière, nous nous sommes tournés vers une méthode qui utilise justement celle-ci : la diffusion dynamique de lumière ou DLS (Dynamic Light Scattering). Nous avons développé son application à la migration cellulaire, afin d'obtenir la distribution des déplacements relatifs des cellules au cours du temps. Cette mesure est faite sans utiliser de marqueurs spécifiques et est applicable à des sphéroïdes allant jusqu'à 400 μm de diamètre. Nous avons ainsi mis en évidence une organisation radiale du sphéroïde en termes de mobilité, avec des cellules rapides en surface et plus lentes au centre. Nous avons aussi montré qu'en appliquant une contrainte au sphéroïde, la vitesse moyenne diminue jusqu'à être réduite de moitié pour des pressions supérieures à 15kPa. Une autre équipe a mesuré par ailleurs une augmentation de la vitesse des cellules en surface suite à une compression, ce qui indique que l'organisation radiale se retrouve dans la réponse à la pression. Nous avons montré que cette sensibilité à la pression est une propriété qui émerge de l'organisation 3D du tissu, dans laquelle la matrice extracellulaire joue un rôle primordial. Enfin, pour explorer les possibilités qu'offre notre technique, nous l'avons appliquée à une autre question : comment la migration des macrophages est-elle affectée par les signaux provenant de cellules apoptotiques ? Les résultats ont montré que les cellules apoptotiques précoces augmentent la vitesse des macrophages tandis que les cellules apoptotiques tardives la réduisent. D'un cas à l'autre, la longueur de persistance du mouvement est conservée.
As a tumor grows, it exerts a mechanical pressure on its surrounding tissue and is compressed back as a reaction. Recent experiments on an in vitro tumor model, called spheroid, have shown that this pressure is crucial for the fate of the cancerous tissue. In particular, the pressure slows down its growth, but makes it more invasive. To further understand the latter effect, we decided to study the migration of cells inside spheroids under pressure. However, imaging the inside of a spheroid is technically challenging as usual microscopy methods do not work on thick tissues (> 100 μm). Standard imaging methods are limited in terms of depth penetration because of light scattering. For this reason, we decided to take advantage…
Advisors/Committee Members: Cappello, Giovanni (thesis director).
Subjects/Keywords: Diffusion dynamique de lumière; Motilité cellulaire; Agrégats multicellulaires; Cancer; Speckle; Mécanique des tissus; Dynamic Light Scattering; Cell motility; Multicellular aggregates; Cancer; Speckle; Mechanical properties of tissues; 530
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APA (6th Edition):
Brunel, B. (2018). Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering. (Doctoral Dissertation). Université Grenoble Alpes (ComUE). Retrieved from http://www.theses.fr/2018GREAY047
Chicago Manual of Style (16th Edition):
Brunel, Benjamin. “Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering.” 2018. Doctoral Dissertation, Université Grenoble Alpes (ComUE). Accessed January 20, 2021.
http://www.theses.fr/2018GREAY047.
MLA Handbook (7th Edition):
Brunel, Benjamin. “Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering.” 2018. Web. 20 Jan 2021.
Vancouver:
Brunel B. Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering. [Internet] [Doctoral dissertation]. Université Grenoble Alpes (ComUE); 2018. [cited 2021 Jan 20].
Available from: http://www.theses.fr/2018GREAY047.
Council of Science Editors:
Brunel B. Mesure des déplacements cellulaires dans les tissus non transparents : une application de la diffusion dynamique de la lumière : Measuring cell displacements inside non-transparent tissues : an application of dynamic light scattering. [Doctoral Dissertation]. Université Grenoble Alpes (ComUE); 2018. Available from: http://www.theses.fr/2018GREAY047
Ryerson University
9.
Razani, Marjan.
Optical Coherence Tomography Detection of Shear Wave.
Degree: 2012, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A1414
► In this work, we explored the potential of measuring shear wave propagation using Optical Coherence Elastography (OCE). Shear waves were generated using a 20 MHz…
(more)
▼ In this work, we explored the potential of measuring shear wave propagation using Optical Coherence Elastography (OCE). Shear waves were generated using a 20 MHz piezoelectric transducer transmitting sine-wave bursts of 400 μs, synchronized with the OCT swept source wavelength sweep. The acoustic radiation force was applied to two gelatin phantoms (differing in gelatin concentration by weight, 8% vs 14%, respectively). Differential OCT phase maps, measured with and without the acoustic radiation force, demonstrate microscopic displacement generated by shear wave propagation in these phantoms of different stiffness. The shear wave speeds for the 14% and 8% gelatin-titanium dioxide phantoms were 2.24 0.06 m/s and 1.49 0.05 m/s and also the shear modulus estimated using SW-OCE was 5.3±0.2 kPa and 2.3±0.1 kPa for the 14% and 8% gelatin-titanium dioxide phantoms, respectively. The results demonstrate the feasibility of this technique for measuring the
mechanical properties of tissue.
Advisors/Committee Members: Kolios, Michael C. (Thesis advisor).
Subjects/Keywords: Optical coherence tomography – Measurement; Shear waves – Measurement; Tissues – Mechanical properties; Tissues – Imaging; Imaging systems in medicine
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APA (6th Edition):
Razani, M. (2012). Optical Coherence Tomography Detection of Shear Wave. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A1414
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Razani, Marjan. “Optical Coherence Tomography Detection of Shear Wave.” 2012. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A1414.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Razani, Marjan. “Optical Coherence Tomography Detection of Shear Wave.” 2012. Web. 20 Jan 2021.
Vancouver:
Razani M. Optical Coherence Tomography Detection of Shear Wave. [Internet] [Thesis]. Ryerson University; 2012. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1414.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Razani M. Optical Coherence Tomography Detection of Shear Wave. [Thesis]. Ryerson University; 2012. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1414
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Ryerson University
10.
Bhatt, Jagdish.
Monitoring electric field induced changes in biological tissues and phantoms using ultrasound.
Degree: 2015, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A3767
► An external electric field can induce mechanical changes depending on the amplitude, frequency and duration of the applied electric field. This study is focused on…
(more)
▼ An external electric field can induce
mechanical changes depending on the amplitude, frequency and duration of the applied electric field. This study is focused on monitoring the electric/electro-kinetic effects of real biological
tissues (in vitro) and gelatin phantoms with high spatial resolution. In this study, we investigated the mean of the signal spectrum at the modulation frequency, root-mean-square of the noise in the spectrum, and signal-to-noise ratio (SNR) during the application of low-frequency AC electric field in
tissues and phantoms. Our results show that the EIMC SNR can indicate the existence of AC electric current in samples, rather than be directly related to the sample's electro-kinetic
properties of the samples. We also found that the SNR varies spatially even for homogenous samples. These two features might hinder the development of the proposed method to be a viable clinical diagnostic technique.
Advisors/Committee Members: Ryerson University (Degree grantor).
Subjects/Keywords: Tissues – Mechanical properties; Biomedical materials – Mechanical properties; Ultrasonic waves – Physiological effect; Electromagnetism – Physiological effect; Tomography; Ultrasonic imaging; Ultrasonics in biology
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APA (6th Edition):
Bhatt, J. (2015). Monitoring electric field induced changes in biological tissues and phantoms using ultrasound. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A3767
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Bhatt, Jagdish. “Monitoring electric field induced changes in biological tissues and phantoms using ultrasound.” 2015. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A3767.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bhatt, Jagdish. “Monitoring electric field induced changes in biological tissues and phantoms using ultrasound.” 2015. Web. 20 Jan 2021.
Vancouver:
Bhatt J. Monitoring electric field induced changes in biological tissues and phantoms using ultrasound. [Internet] [Thesis]. Ryerson University; 2015. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A3767.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bhatt J. Monitoring electric field induced changes in biological tissues and phantoms using ultrasound. [Thesis]. Ryerson University; 2015. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A3767
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Michigan State University
11.
Atkinson, Theresa Staton.
Experimental and analytical development of a poroelastic finite element model for tendon.
Degree: PhD, Department of Materials Science and Mechanics, 1998, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:26802
Subjects/Keywords: Tendons – Mechanical properties; Connective tissues – Mechanical properties; Biomechanics; Microstructure
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APA (6th Edition):
Atkinson, T. S. (1998). Experimental and analytical development of a poroelastic finite element model for tendon. (Doctoral Dissertation). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:26802
Chicago Manual of Style (16th Edition):
Atkinson, Theresa Staton. “Experimental and analytical development of a poroelastic finite element model for tendon.” 1998. Doctoral Dissertation, Michigan State University. Accessed January 20, 2021.
http://etd.lib.msu.edu/islandora/object/etd:26802.
MLA Handbook (7th Edition):
Atkinson, Theresa Staton. “Experimental and analytical development of a poroelastic finite element model for tendon.” 1998. Web. 20 Jan 2021.
Vancouver:
Atkinson TS. Experimental and analytical development of a poroelastic finite element model for tendon. [Internet] [Doctoral dissertation]. Michigan State University; 1998. [cited 2021 Jan 20].
Available from: http://etd.lib.msu.edu/islandora/object/etd:26802.
Council of Science Editors:
Atkinson TS. Experimental and analytical development of a poroelastic finite element model for tendon. [Doctoral Dissertation]. Michigan State University; 1998. Available from: http://etd.lib.msu.edu/islandora/object/etd:26802
University of Johannesburg
12.
Wellmanns, Rainer Gregor.
An investigation into the structural behaviour of 350W structural steel axial members.
Degree: 2009, University of Johannesburg
URL: http://hdl.handle.net/10210/2469
► M.Ing.
Grade 350W structural steel was introduced into the South African steel market to replace its predecessor 300W structural steel. 350W structural steel has a…
(more)
▼ M.Ing.
Grade 350W structural steel was introduced into the South African steel market to replace its predecessor 300W structural steel. 350W structural steel has a 50 MPa increase in its minimum yield strength. Currently, little or no experimental data exists that describes the behaviour of full scale 350W structural sections. No extensive comparisons between 350W and 300W, as to their structural behaviour, exist. The main aim of this investigation was firstly to determine if the minimum yield strength was fully realised throughout typical sections and if the increase in yield strength changed the yielding behaviour of the material. Secondly, the effect that the increased yield strength has on the structural resistance of axial compression members. The investigation largely consisted of an evaluation of firstly the material and then secondly the structural behaviour of full scale member sections as axial members. It was found that all the sections tested complied with the minimum specified yield strength of 350 MPa. In general, 350W hot rolled structural steel yields more gradually than 300W hot rolled structural steel. This increase is small and seems to be of little significance as far as the overall behaviour is concerned. In general, the increase in minimum yield strength from 300 MPa to 350 MPa has realised an increase in critical buckling strength well into the medium slenderness ratio region and is beneficial for members of short and intermediate lengths. The data seems to indicate that SANS 10162-1:2005 can be used with confidence when designing axial compression members in 350W hot rolled structural steel.
Subjects/Keywords: Mechanical properties of structural steel
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APA (6th Edition):
Wellmanns, R. G. (2009). An investigation into the structural behaviour of 350W structural steel axial members. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/2469
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wellmanns, Rainer Gregor. “An investigation into the structural behaviour of 350W structural steel axial members.” 2009. Thesis, University of Johannesburg. Accessed January 20, 2021.
http://hdl.handle.net/10210/2469.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wellmanns, Rainer Gregor. “An investigation into the structural behaviour of 350W structural steel axial members.” 2009. Web. 20 Jan 2021.
Vancouver:
Wellmanns RG. An investigation into the structural behaviour of 350W structural steel axial members. [Internet] [Thesis]. University of Johannesburg; 2009. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10210/2469.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wellmanns RG. An investigation into the structural behaviour of 350W structural steel axial members. [Thesis]. University of Johannesburg; 2009. Available from: http://hdl.handle.net/10210/2469
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Northeastern University
13.
Oftadeh, Ramin.
Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure.
Degree: PhD, Department of Mechanical and Industrial Engineering, 2016, Northeastern University
URL: http://hdl.handle.net/2047/D20212379
► Materials with structural hierarchy over nanometer to millimeter length scales are found throughout Kingdoms Plantae and Animalia. The idea of using structural hierarchy in engineering…
(more)
▼ Materials with structural hierarchy over nanometer to millimeter length scales are found throughout Kingdoms Plantae and Animalia. The idea of using structural hierarchy in engineering structures and materials goes back at least to Eiffel's Garabit Viaduct and then Tower. Incorporating hierarchy into honeycomb lattice structures has been the focus of a number of studies and has significance with regard to the application of honeycombs in impact energy absorption and structural protection, thermal isolation and as the structural core of sandwich panels. Here we explore the mechanical properties of two kind of cellular structures: hierarchical honeycombs and trabecular bone.; Hexagonal honeycomb structures are known for their high strength and low weight. We construct a new class of fractal-appearing cellular metamaterials by replacing each three-edge vertex of a base hexagonal network with a smaller hexagon and iterating this process. The mechanical properties of the structure after different orders of the iteration are optimized. We find that the optimal structure (with highest in-plane stiffness for a given weight ratio) is self-similar but requires higher order hierarchy as the density vanishes. These results offer insights into how incorporating hierarchy in the material structure can create low-density metamaterials with desired properties and function.; The second aim of this study was to explore the hierarchical arrangement of structural properties in cortical and trabecular bone and to determine a mathematical model that accurately predicts the tissue's mechanical properties as a function of these indices. By using a variety of analytical techniques, we were able to characterize the structural and compositional properties of cortical and trabecular bones, as well as to determine the suitable mathematical model to predict the tissue's mechanical properties using a continuum micromechanics approach. Our hierarchical analysis demonstrated that the differences between cortical and trabecular bone reside mainly at the micro- and ultrastructural levels. By gaining a better appreciation of the similarities and differences between the two bone types, we would be able to provide a better assessment and understanding of their individual roles, as well as their contribution to bone health overall.
Subjects/Keywords: bone composition; bone structure; cellular structures; cortical bone; structural hierarchy; trabecular bone; Structural design; Bone; Mechanical properties; Connective tissues; Mechanical properties; Honeycomb structures; Mechanical properties; Composite materials; Cells
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APA (6th Edition):
Oftadeh, R. (2016). Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure. (Doctoral Dissertation). Northeastern University. Retrieved from http://hdl.handle.net/2047/D20212379
Chicago Manual of Style (16th Edition):
Oftadeh, Ramin. “Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure.” 2016. Doctoral Dissertation, Northeastern University. Accessed January 20, 2021.
http://hdl.handle.net/2047/D20212379.
MLA Handbook (7th Edition):
Oftadeh, Ramin. “Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure.” 2016. Web. 20 Jan 2021.
Vancouver:
Oftadeh R. Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure. [Internet] [Doctoral dissertation]. Northeastern University; 2016. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/2047/D20212379.
Council of Science Editors:
Oftadeh R. Hierarchical analysis and multiscale modelling of cellular structures: from meta materials to bone structure. [Doctoral Dissertation]. Northeastern University; 2016. Available from: http://hdl.handle.net/2047/D20212379
University of Oxford
14.
Southern, James Alastair.
Mathematical and computational modelling of ultrasound elasticity imaging.
Degree: PhD, 2006, University of Oxford
URL: http://ora.ox.ac.uk/objects/uuid:242fddf0-ef9c-4a90-88f5-c7b41f4bda5a
;
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442961
► In this thesis a parameter recovery method for use in ultrasound elasticity imaging is developed. Elasticity imaging is a method for using a series of…
(more)
▼ In this thesis a parameter recovery method for use in ultrasound elasticity imaging is developed. Elasticity imaging is a method for using a series of ultrasound images (and the displacement field between them) to estimate the spatial variation of the stiffness of the tissue being imaged. Currently iterative methods are used to do this: a model of tissue mechanics is assumed and a large number of simulations using varying parameters are compared to the actual displacement field. The aim of this work is to develop a solution method that works back from the known displacement field to determine the tissue properties, reducing the number of simulations that must be performed to one. The parameter recovery method is based on the formulation and direct solution of the 2-d linear elasticity inverse problem using finite element methods. The inverse problem is analyzed mathematically and the existence and uniqueness of solutions is described for varying numbers of displacement fields and appropriate boundary conditions. It is shown to be hyperbolic (and so difficult to solve numerically) and then reformulated as a minimization problem with hyperbolic Euler-Lagrange equations. A finite element solution of the minimization problem is developed and implemented. The results of the finite element implementation are shown to work well in recovering the parameters used in numerical simulations of the linear elasticity forward problem so long as these are continuous. The method is shown to be robust in dealing with small errors in displacement estimation and larger errors in the boundary values of the parameters. The method is also tested on displacement fields calculated from series of real ultrasound images. The validity of modelling the ultrasound elasticity imaging process as a 2-d problem is discussed. The assumption of plane strain is shown not to be valid and methods for extending the parameter recovery method to 3 dimensions once 3-d ultrasound becomes more widely used are described (but not implemented).
Subjects/Keywords: 616.07543015118; Elasticity : Mathematical models : Tissues : Mechanical properties : Lagrange equations
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APA (6th Edition):
Southern, J. A. (2006). Mathematical and computational modelling of ultrasound elasticity imaging. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:242fddf0-ef9c-4a90-88f5-c7b41f4bda5a ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442961
Chicago Manual of Style (16th Edition):
Southern, James Alastair. “Mathematical and computational modelling of ultrasound elasticity imaging.” 2006. Doctoral Dissertation, University of Oxford. Accessed January 20, 2021.
http://ora.ox.ac.uk/objects/uuid:242fddf0-ef9c-4a90-88f5-c7b41f4bda5a ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442961.
MLA Handbook (7th Edition):
Southern, James Alastair. “Mathematical and computational modelling of ultrasound elasticity imaging.” 2006. Web. 20 Jan 2021.
Vancouver:
Southern JA. Mathematical and computational modelling of ultrasound elasticity imaging. [Internet] [Doctoral dissertation]. University of Oxford; 2006. [cited 2021 Jan 20].
Available from: http://ora.ox.ac.uk/objects/uuid:242fddf0-ef9c-4a90-88f5-c7b41f4bda5a ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442961.
Council of Science Editors:
Southern JA. Mathematical and computational modelling of ultrasound elasticity imaging. [Doctoral Dissertation]. University of Oxford; 2006. Available from: http://ora.ox.ac.uk/objects/uuid:242fddf0-ef9c-4a90-88f5-c7b41f4bda5a ; http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.442961
University of Hong Kong
15.
范菁.
Heat transport in
nanofluids and biological tissues.
Degree: 2012, University of Hong Kong
URL: http://hdl.handle.net/10722/174465
► The present work contains two parts: nanofluids and bioheat transport, both involving multiscales and sharing some common features. The former centers on addressing the three…
(more)
▼ The present work contains two parts:
nanofluids and bioheat transport, both involving multiscales and
sharing some common features. The former centers on addressing the
three key issues of nanofluids research: (i) what is the macroscale
manifestation of microscale physics, (ii) how to optimize
microscale physics for the optimal system performance, and (iii)
how to effectively manipulate at microscale. The latter develops an
analytical theory of bioheat transport that includes: (i)
identification and contrast of the two approaches for developing
macroscale bioheat models: the mixture-theory (scaling-down) and
porous-media (scaling-up) approaches, (ii) rigorous development of
first-principle bioheat model with the porous-media approach, (iii)
solution-structure theorems of dual-phase-lagging (DPL) bioheat
equations, (iv) practical case studies of bioheat transport in skin
tissues and during magnetic hyperthermia, and (v) rich effects of
interfacial convective heat transfer, blood velocity, blood
perfusion and metabolic reaction on blood and tissue macroscale
temperature fields. Nanofluids, fluid suspensions of
nanostructures, find applications in various fields due to their
unique thermal, electronic, magnetic, wetting and optical
properties that can be obtained via engineering nanostructures. The
present numerical simulation of structure-property correlation for
fourteen types of two/three-dimensional nanofluids signifies the
importance of nanostructure’s morphology in determining nanofluids’
thermal conductivity. The success of developing high-conductive
nanofluids thus depends very much on our understanding and
manipulation of the morphology. Nanofluids with conductivity of
upper Hashin-Shtrikman bounds can be obtained by manipulating
structures into an interconnected configuration that disperses the
base fluid and thus significantly enhancing the particle-fluid
interfacial energy transport. The numerical simulation also
identifies the particle’s radius of gyration and non-dimensional
particle-fluid interfacial area as two characteristic parameters
for the effect of particles’ geometrical structures on the
effective thermal conductivity. Predictive models are developed as
well for the thermal conductivity of typical nanofluids. A
constructal approach is developed to find the constructal
microscopic physics of nanofluids for the optimal system
performance. The approach is applied to design nanofluids with any
branching level of tree-shaped microstructures for cooling a
circular disc with uniform heat generation and central heat sink.
The constructal configuration and system thermal resistance have
some elegant universal features for both cases of specified aspect
ratio of the periphery sectors and given the total number of slabs
in the periphery sectors. The numerical simulation on the bubble
formation in T-junction microchannels shows: (i) the mixing
enhancement inside liquid slugs between microfluidic bubbles, (ii)
the preference of T-junctions with small channel width ratio for
either producing smaller…
Advisors/Committee Members: Wang, L (advisor).
Subjects/Keywords: Nanofluids - Mechanical properties.; Heat -
Transmission - Mathematical models.; Tissues
- Mechanical properties.
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
范菁. (2012). Heat transport in
nanofluids and biological tissues. (Thesis). University of Hong Kong. Retrieved from http://hdl.handle.net/10722/174465
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
范菁. “Heat transport in
nanofluids and biological tissues.” 2012. Thesis, University of Hong Kong. Accessed January 20, 2021.
http://hdl.handle.net/10722/174465.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
范菁. “Heat transport in
nanofluids and biological tissues.” 2012. Web. 20 Jan 2021.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
范菁. Heat transport in
nanofluids and biological tissues. [Internet] [Thesis]. University of Hong Kong; 2012. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10722/174465.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
范菁. Heat transport in
nanofluids and biological tissues. [Thesis]. University of Hong Kong; 2012. Available from: http://hdl.handle.net/10722/174465
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Not specified: Masters Thesis or Doctoral Dissertation
University of Limerick
16.
O'Connor, Gerard.
Development of high temperature tensile test machine.
Degree: 2017, University of Limerick
URL: http://hdl.handle.net/10344/6577
► peer-reviewed
The tensile test is one of the most commonly used tests in attempting to establish the mechanical properties of a material. This test is…
(more)
▼ peer-reviewed
The tensile test is one of the most commonly used tests in attempting to establish the mechanical properties of a material. This test is completed by holding a speci-men of known cross sectional area rigidly between a fixed beam and a moving beam (the crosshead). The test then involves loading the specimen and increasing the load until the specimen fractures.
Currently in the School of Engineering, a high temperature tensile testing machine is available. This machine consists of a 25kN column-type screw driven tensile testing machine with an electric furnace mounted on its base. The tensile test spec-imens are held within in furnace in specially manufactured grip holders which are attached to the machine cross head and machine base.
There were many underlying issues which required addressing to ensure that the facility was suitable for research activity. These issues included:
Cycle times needed to be improved,
Data and test results need to be of the highest quality and accuracy,
Tensile test machine was required to be operational at high temperature,
Ease of test set-up in relation to specimen change over and removal from furnace.
This project aimed to address the above issues so that the test rig would be more user friendly and could be used as a teaching aid for students as well as research projects.
Similar equipment to this existing furnace can be purchased but at enormous cost. Hence, the current project added significant value to the stock of materials testing equipment at the School of Engineering at the University of Limerick.
Advisors/Committee Members: Tiernan, Peter.
Subjects/Keywords: tensile test; mechanical properties; School of Engineering
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APA (6th Edition):
O'Connor, G. (2017). Development of high temperature tensile test machine. (Thesis). University of Limerick. Retrieved from http://hdl.handle.net/10344/6577
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
O'Connor, Gerard. “Development of high temperature tensile test machine.” 2017. Thesis, University of Limerick. Accessed January 20, 2021.
http://hdl.handle.net/10344/6577.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
O'Connor, Gerard. “Development of high temperature tensile test machine.” 2017. Web. 20 Jan 2021.
Vancouver:
O'Connor G. Development of high temperature tensile test machine. [Internet] [Thesis]. University of Limerick; 2017. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10344/6577.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
O'Connor G. Development of high temperature tensile test machine. [Thesis]. University of Limerick; 2017. Available from: http://hdl.handle.net/10344/6577
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Cincinnati
17.
Patwardhan, Madhura.
Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques.
Degree: MS, Engineering and Applied Science: Mechanical
Engineering, 2013, University of Cincinnati
URL: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367943908
► Many problems in the biomedical field can be helped by the engineering devices that have special functions to address the problem. Tissue diagnostics is an…
(more)
▼ Many problems in the biomedical field can be helped by
the engineering devices that have special functions to address the
problem. Tissue diagnostics is an area where a fast and simple
technology could be beneficial for cancer screening and to monitor
the integration of biomedical implants with tissue. Another area of
medicine that promises large benefits is the development of
biodegradable metal implants. Biodegradable metal implants have the
potential to improve regenerative medicine in the areas of
cardiovascular, orthopedic, and craniofacial implants. Both the
areas of tissue diagnostics and biodegradable implant control can
be improved with electrochemical measurements and corrosion
technologies. This thesis develops electrochemical techniques to
diagnose disease in tissue, to differentiate tissue types, and to
control on demand the degradation of metal implants. The research
work conducted here deals with using the method of Electrochemical
Impedance Spectroscopy (EIS) for understanding tissue-implant
interface phenomenon. Tests were conducted in mice to see the
change in impedance with the degradation of the Mg implant for
studying the integration of the implant with tissue. Experiments
showed that the impedance decreased with time and this change in
impedance was attributed to the changes at the surface of the
implant on integration with tissue environment. Studying the
impedance scans of the implanted electrodes over a longer period of
time will be helpful in understanding the tissue-implant interface
until the implant degrades. Tissue-based diagnostics is also
investigated for cancer screening. EIS of cancer samples obtained
from human lungs showed there is a difference in the impedance of
cancerous tissue and normal tissue at low frequencies. But this
difference was not always repeatable with different samples and
probing positions as tissue is highly anisotropic. High frequency
measurements with a high frequency vector network analyzer (VNA)
indicated that tissue-based diagnostics might be made more
sensitive by using nanoparticles in conjunction with coaxial probes
for measuring the electrical conduction
properties of tissue.
Lastly, the development of a wireless corrosion acceleration system
was investigated based upon electrochemical corrosion. Two
approaches were used to develop the corrosion acceleration system;
the method of galvanic corrosion; and by using the transformer
principle. Preliminary tests were conducted to determine how
alternating current affects the corrosion rate of Mg compared to
direct current. Also, it was seen that the corrosion of the
biomedical implants can be successfully controlled by using a
magnetic reed switch. This was thought to be a simple way to
control corrosion wirelessly and the switch can also be made
biodegradable. In summary, this thesis showed that the technique of
EIS can be used to gather information about the state of the
implant in vivo. On improving the sensitivity of the method, it
could also find application in early cancer diagnosis by helping to…
Advisors/Committee Members: Schulz, Mark (Committee Chair).
Subjects/Keywords: Mechanical Engineering; dielectric properties of tissue
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APA (6th Edition):
Patwardhan, M. (2013). Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques. (Masters Thesis). University of Cincinnati. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367943908
Chicago Manual of Style (16th Edition):
Patwardhan, Madhura. “Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques.” 2013. Masters Thesis, University of Cincinnati. Accessed January 20, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367943908.
MLA Handbook (7th Edition):
Patwardhan, Madhura. “Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques.” 2013. Web. 20 Jan 2021.
Vancouver:
Patwardhan M. Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques. [Internet] [Masters thesis]. University of Cincinnati; 2013. [cited 2021 Jan 20].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367943908.
Council of Science Editors:
Patwardhan M. Tissue-Based Diagnostics and Corrosion Control of
Biodegradable Implants using Electrochemical Techniques. [Masters Thesis]. University of Cincinnati; 2013. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1367943908
18.
Yoon, Sangpil.
Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force.
Degree: PhD, Mechanical Engineering, 2012, University of Texas – Austin
URL: http://hdl.handle.net/2152/ETD-UT-2012-05-5132
► This dissertation introduces a new approach to measure the mechanical properties of soft tissues. A laser-induced microbubble, created by focusing a single nanosecond laser pulse…
(more)
▼ This dissertation introduces a new approach to measure the
mechanical properties of soft
tissues. A laser-induced microbubble, created by focusing a single nanosecond laser pulse with a custom-made objective lens, was created at desired locations inside a tissue sample. An acoustic radiation force was generated by a low frequency transducer to displace the microbubble. A custom-built high pulse repetition frequency (PRF) ultrasound system, consisting of two 25 MHz single element transducers, was used to track the dynamics of the microbubble. Reconstruction of the
mechanical properties at the specific location in a tissue sample was performed using a theoretical model, which calculated the dynamics of a microbubble under an externally applied force in a viscoelastic medium. The theoretical model and the high PRF ultrasound system were successfully validated in both gelatin phantoms and ex vivo bovine crystalline lenses.
Age-related sclerosis of the crystalline lenses from bovine was clearly detected, which might be linked to changes in the crystalline. Location-dependent variation explained that the outer cortex and the inner nucleus had different
mechanical properties. In the old and young porcine vitreous humors, age-related changes were not found.
However, local variations of the
mechanical properties were discovered, which may coincide with the different distributions of the molecular compositions. The laser-induced microbubble approach shows potential for future research into the origin of physiological phenomena and the development of inherent disorders in the eye. I hope that further studies – in the development of a more suitable theoretical model for the microbubble dynamics, in extension to in vivo applications, and in defining the relationship of the
mechanical properties to molecular components in the eye – may provide a plan for the therapeutic treatment of eye-related diseases.
Advisors/Committee Members: Emelianov, Stanislav Y. (advisor), Hamilton, Mark F. (committee member), Aglyamov, Salavat R. (committee member), Wilson, Preston S. (committee member), Karpiouk, Andrei B. (committee member), Larin, Kirill (committee member).
Subjects/Keywords: Mechanical properties of soft tissues; Viscoelastic properties; Acoustic radiation force; Laser-induced microbubble; The crystalline lens; The vitreous humor
…loss of vision.
Reliable measurements of the mechanical properties of ocular tissues may… …the mechanical
properties of ex vivo animal ocular tissues such as the crystalline lens and… …pulse, to measure the localized
mechanical properties of either soft tissues or a tissue… …81
Chapter 5: The mechanical properties of ex vivo animal crystalline lens: age-related… …97
Chapter 6: Local variations of the mechanical properties of porcine vitreous humor…
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APA (6th Edition):
Yoon, S. (2012). Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/ETD-UT-2012-05-5132
Chicago Manual of Style (16th Edition):
Yoon, Sangpil. “Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force.” 2012. Doctoral Dissertation, University of Texas – Austin. Accessed January 20, 2021.
http://hdl.handle.net/2152/ETD-UT-2012-05-5132.
MLA Handbook (7th Edition):
Yoon, Sangpil. “Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force.” 2012. Web. 20 Jan 2021.
Vancouver:
Yoon S. Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2012. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/2152/ETD-UT-2012-05-5132.
Council of Science Editors:
Yoon S. Estimation of the mechanical properties of soft tissues using a laser-induced microbubble interrogated by acoustic radiation force. [Doctoral Dissertation]. University of Texas – Austin; 2012. Available from: http://hdl.handle.net/2152/ETD-UT-2012-05-5132
Rutgers University
19.
Kim, Kyunghan.
The thermal response of biological tissue subjected to short-pulsed irradiations:.
Degree: PhD, Mechanical and Aerospace Engineering, 2008, Rutgers University
URL: http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051761
► A combined transient radiation and hyperbolic heat conduction model is developed to simulate heat transfer of biological tissue subjected to short pulsed irradiations. For modeling…
(more)
▼ A combined transient radiation and hyperbolic heat conduction model is developed to simulate heat transfer of biological tissue subjected to short pulsed irradiations. For modeling the ultrafast radiation heat transfer, the Transient Discrete Ordinate Method (TDOM) is developed in the two-dimensional axisymmetric cylindrical coordinates. The hyperbolic conduction model is solved by MacCormack’s scheme with error terms correction. One combination model of radiation and heat conduction is that the radiation transfer is initiated by short pulse train irradiating until millisecond time scale and heat conduction transfer is followed. The temperature always increases by the radiation transfer and the heat is dissipated to the surrounding tissue by the hyperbolic heat conduction. The typical characteristic of the hyperbolic conduction is the thermal wave propagation rather than thermal diffusion with indefinite speed. It is found that the maximum local temperatures are higher in the hyperbolic prediction than the parabolic prediction, which can be 7% higher in the modeled dermis tissue. After about 10 thermal relaxation times, thermal waves fade away and the predictions between the hyperbolic and parabolic models are closely consistent.
Other combination model is that radiation and conduction transfer always occurs together until a second time regime. The temperature prediction is compared with the experimental result provided by Dr. Kunal Mitra’s group. Generally, the hyperbolic model combined with radiative heat transfer shows very similar result with the experimental data. It also shows high temperature increment near the laser deposition area compared with the parabolic model.
Own experimental study is conducted to evaluate the hyperbolic heat conduction phenomena. The fresh chicken tissue which is conserved the room temperature is suddenly contacted the ice block. Some of the results support the hyperbolic model by the temperature suddenly dropping rather that gradual temperature change.
The high absorbing tissue can enhance the radiation energy absorption and temperature increment is higher. The temperature increment is localized in the tissue surface region in the high scattering tissue. The focused laser beam played a role of temperature amplification around the focal region. The finer grid system is employed to catch up steep change of gradient of radiation energy absorption.
Advisors/Committee Members: Kim, Kyunghan (author), Guo, Zhixiong (chair), Jaluria, Yogesh (internal member), Lin, Hao (internal member), Mitra, Kunal (outside member).
Subjects/Keywords: Tissues – Thermal properties; Tissues – Effect of radiation on; Lasers – Physiological effect
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APA (6th Edition):
Kim, K. (2008). The thermal response of biological tissue subjected to short-pulsed irradiations:. (Doctoral Dissertation). Rutgers University. Retrieved from http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051761
Chicago Manual of Style (16th Edition):
Kim, Kyunghan. “The thermal response of biological tissue subjected to short-pulsed irradiations:.” 2008. Doctoral Dissertation, Rutgers University. Accessed January 20, 2021.
http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051761.
MLA Handbook (7th Edition):
Kim, Kyunghan. “The thermal response of biological tissue subjected to short-pulsed irradiations:.” 2008. Web. 20 Jan 2021.
Vancouver:
Kim K. The thermal response of biological tissue subjected to short-pulsed irradiations:. [Internet] [Doctoral dissertation]. Rutgers University; 2008. [cited 2021 Jan 20].
Available from: http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051761.
Council of Science Editors:
Kim K. The thermal response of biological tissue subjected to short-pulsed irradiations:. [Doctoral Dissertation]. Rutgers University; 2008. Available from: http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051761
Ryerson University
20.
Elsayed, Abdallah.
Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication.
Degree: 2010, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A1503
► For the A1-5Ti-1B grain refiner, the addition of 0.1 wt.% provided a 68 % reduction in grain size as compared to the unrefined AZ91E alloy…
(more)
▼ For the A1-5Ti-1B grain refiner, the addition of 0.1 wt.% provided a 68 % reduction in grain size as compared to the unrefined AZ91E alloy at a holding time of five minutes. Grain growth restriction by TiB₂ particles was the source of grain refinement. With the addition of A1-5Ti-1B, only a small reduction in hot tearing susceptibility ws observed because large TiA1₃ particles bonded poorly with the eutectic and blocked feeding channels.The addition of 1.0 wt.% A1-1Ti-3B provided a grain size reduction of 63% as compared to the unrefined AZ91E alloy at a holding time of five minutes. The grain refinement with A1-1Ti-3B addition was attributed to a combination of TiB₂ grain growth restriction and A1B₂ nucleating sites. A significant reduction in hot tearing susceptibility was observed with A1-1Ti-3B addition as a result of a higher cooling rate and shorter local soldification time as compared to the AZ91E alloy. The reduction in hot tearing susceptibility was attributed to the good interface between eutectic and TiB₂ particles. Both grain refiners demonstrated a good resistance to fading during the holding times investigated. In addition, the AZ91E + A1-5Ti-1B and AZ91E + A1-1Ti-3B castings showed much fewer dislocation networks as compared to the untreated AZ91E casting.The development of efficient A1-Ti-B refiners can also improve castability of magnesium alloys. In addition, the fade resistant A1-Ti-B grain refiners can reduce operating costs and maintain productivity on the foundry floor. Thus, magnesium alloy with A1-Ti-B treatment have the potential for more demanding structural applications in the automobile and aerospace industries.Vehicle weight in the aerospace and automotive industries directly impacts carbon emissions and fuel efficiency. An increase in the use of lightweight materials for structural applications will result in lighter vehicles. Low density materials, such as magnesium (1.74 g/cm³) are a potential alternative to aluminium (2.70 g/cm³), to reduce component weight in structural applications.However, current magnesium alloys still do not have adequate mechanical properties and castability to meet the performance specifications of the automotive and aerospace industries. Grain refinement can significantly improve mechanical properties and reduce hot tearing during permanent mould casting. Recently, Al-Ti-B based grain refiners have shown potential in grain refining magnesium-aluminum alloys such as AZ91E. This study investigates the grain refining efficiency and fading of A1-5Ti-1B and A1-1Ti-3B in AZ91E magnesium alloy and their subsequent effect on hot tearing.The grain refiners were added at 0.1, 0.2, 0.5 and 1.0 wt.% levels. For the grain refinement and fading experiments, the castings were prepared using graphite moulds with holding times of 5, 10 and 20 minutes. For the hot tearing experiments, castings were produced representing the optimal addition level of each grain refiner. The castings were prepared using a permanent mould with pouring and mould temperatures of 720 and 180 ºC,…
Subjects/Keywords: Magnesium alloys – Mechanical properties; Strength of materials – Mathematical models; Alloys – Mechanical properties; Molding (Founding)
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APA (6th Edition):
Elsayed, A. (2010). Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A1503
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Elsayed, Abdallah. “Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication.” 2010. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A1503.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Elsayed, Abdallah. “Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication.” 2010. Web. 20 Jan 2021.
Vancouver:
Elsayed A. Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication. [Internet] [Thesis]. Ryerson University; 2010. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1503.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Elsayed A. Novel grain refinement of AZ91E magnesium alloy and the effect on hot tearing during solidfication. [Thesis]. Ryerson University; 2010. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A1503
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Ryerson University
21.
D’Elia, Francesco.
A study of hot tearing during solidification of B206 aluminum alloy.
Degree: 2015, Ryerson University
URL: https://digital.library.ryerson.ca/islandora/object/RULA%3A3291
► Aluminum-copper (Al-Cu) alloy B206 is a high strength and ductile alloy showing promise for use in automotive suspension components. Incorporation of lightweight B206 alloy in…
(more)
▼ Aluminum-copper (Al-Cu) alloy B206 is a high strength and ductile alloy showing promise for use in automotive suspension components. Incorporation of lightweight B206 alloy in automotive suspension components may significantly reduce overall vehicle weight and increase the vehicle’s fuel efficiency. However, one of the major factors inhibiting the use of B206 is its high susceptibility to hot tearing during casting. Hot tearing is a complex phenomenon attributed to alloy solidification, microstructure and stress/strain development within a casting. Numerous methods (e.g. preheating of mold, grain refinement, elimination of sharp corners in a component) help to reduce the occurrence of hot tears in castings, but the underlying mechanisms responsible for hot tearing remain ambiguous. This research aims to advance the understanding of the mechanisms responsible for hot tearing in B206 Al alloy.
In this research, the conditions associated with the formation of hot tears in B206 were investigated via ex situ and in situ methods. Titanium was added in three levels (i.e. unrefined, 0.02 and 0.05 wt%) to investigate the effect of grain refinement on hot tearing. Ex situ neutron diffraction strain mapping was carried out on the three B206 castings to determine casting strain and stress. Further, in situ techniques were used to establish the onset temperature and solid
fraction of hot tearing in B206 and to improve the understanding of microstructure development in B206.
The results indicate that titanium additions had a significant impact on the hot tearing susceptibility of B206, by effectively reducing grain size and transforming grain morphology from coarse dendrites to fine globular grains. Further, thermal analysis suggested that grain refinement delayed the onset of dendrite coherency in B206 and therefore enhanced the duration of bulk liquid metal feeding for the refined casting conditions. As a result, the interactive effects of such factors resulted in a more uniform distribution of strain, and subsequent higher resistance to hot tearing for the grain refined castings. Finally, in situ analysis determined the onset solid fraction of hot tearing in B206 and provided an understanding of the role of microstructure on hot tearing in B206.
Advisors/Committee Members: Ravindran, C. Ravi (Thesis advisor), Ryerson University (Degree grantor).
Subjects/Keywords: Aluminum alloys – Mechanical properties.; Strength of materials – Mathematical models.; Alloys – Mechanical properties.; Molding (Founding)
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APA (6th Edition):
D’Elia, F. (2015). A study of hot tearing during solidification of B206 aluminum alloy. (Thesis). Ryerson University. Retrieved from https://digital.library.ryerson.ca/islandora/object/RULA%3A3291
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
D’Elia, Francesco. “A study of hot tearing during solidification of B206 aluminum alloy.” 2015. Thesis, Ryerson University. Accessed January 20, 2021.
https://digital.library.ryerson.ca/islandora/object/RULA%3A3291.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
D’Elia, Francesco. “A study of hot tearing during solidification of B206 aluminum alloy.” 2015. Web. 20 Jan 2021.
Vancouver:
D’Elia F. A study of hot tearing during solidification of B206 aluminum alloy. [Internet] [Thesis]. Ryerson University; 2015. [cited 2021 Jan 20].
Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A3291.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
D’Elia F. A study of hot tearing during solidification of B206 aluminum alloy. [Thesis]. Ryerson University; 2015. Available from: https://digital.library.ryerson.ca/islandora/object/RULA%3A3291
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
22.
Sri Siva, R.
Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -.
Degree: Mechanical Engineering, 2014, Anna University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/22119
► Deep Cryogenic treatment is a supplementary process to the conventional heat treatment for enhancing the mechanical properties of steels 100Cr6 bearing steel is widely used…
(more)
▼ Deep Cryogenic treatment is a supplementary process
to the conventional heat treatment for enhancing the mechanical
properties of steels 100Cr6 bearing steel is widely used to make
the plunger in the fuel injection pumps of diesel engines the most
perplexing wear problem in the fuel injection pump is concerned
with the plunger as this wear affects the engine performance
significantly Deep cryogenic treatment is the process of cooling a
material to extremely low temperatures soaking the material at that
temperature for a prolonged period and then heating it back to room
temperature in order to achieve enhanced mechanical and physical
properties The purpose of this study is to optimise the deep
cryogenic treatment process parameters of 100Cr6 bearing steel for
hardness dimensional stability and wear resistance based on the
Taguchi method with the grey relational analysis The deep cryogenic
treatment parameters considered for the optimisation are the
cooling rate, soaking time soaking temperature and tempering
temperature with the quality targets of higher hardness better
dimensional stability and maximum wear resistance
-
Advisors/Committee Members: Mohan Lal, D.
Subjects/Keywords: Cryogenic treatment; Mechanical engineering; mechanical properties of steels; Taguchi technique
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APA (6th Edition):
Sri Siva, R. (2014). Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -. (Thesis). Anna University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/22119
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Sri Siva, R. “Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -.” 2014. Thesis, Anna University. Accessed January 20, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/22119.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Sri Siva, R. “Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -.” 2014. Web. 20 Jan 2021.
Vancouver:
Sri Siva R. Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -. [Internet] [Thesis]. Anna University; 2014. [cited 2021 Jan 20].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/22119.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Sri Siva R. Optimisation of deep cryogenic treatment for 100cr6
bearing steel using the grey taguchi technique; -. [Thesis]. Anna University; 2014. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/22119
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
23.
Balachandran, Meera.
Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites.
Degree: 2012, Amrita Vishwa Vidyapeetham (University)
URL: http://shodhganga.inflibnet.ac.in/handle/10603/3919
► Polymer nanocomposites are polymeric materials comprising of particles that have at least one dimension in the nanosize range (1 – 100 nm). These materials have…
(more)
▼ Polymer nanocomposites are polymeric materials
comprising of particles that have at least one dimension in the
nanosize range (1 – 100 nm). These materials have properties
superior to conventional microscale composites. Interestingly, the
improvement in properties can be achieved with a very small amount
of nanofiller. In this work acrylonitrile butadiene copolymer
(nitrile rubber) nanocomposites were prepared by a two step
process. In the first step, a masterbatch of nanofiller and nitrile
rubber (NBR) was prepared in an internal mixer. In the second step,
neat NBR was compounded with NBR – nanofiller masterbatch and
compounding ingredients and moulded at 150°C and 20 MPa pressure.
In NBR – nanoclay (layered silicate) composites addition of
nanoclay reduced the cure time and the vulcanization kinetics
closely fitted a first order model. Investigation of morphology
showed exfoliated and few intercalated structures at low nanoclay
content and a tendency to form agglomerates at higher
concentrations. Comparisons were made between experimental data and
the values predicted using various mechanics – based theoretical
models. The tensile strength, modulus and storage modulus increased
up to 5 phr nanoclay content and thereafter showed a decline.
However there was no change in the glass transition temperature.
Addition of nanoclay enhanced thermal stability while decreasing
the gas permeability of nanocomposites. The equilibrium solvent
uptake, diffusion, sorption and permeation coefficients decreased
with nanoclay content with the minimum value at 5 phr nanoclay. The
activation energy for diffusion and permeation for the
nanocomposites were higher than that of neat NBR. The mechanism of
solvent diffusion through the nanocomposites was found to be
Fickian. The dependence of various properties on nanoclay content
was correlated to the morphology of the nanocomposites. The effect
of nanocalcium carbonate (NCC) content, a particulate nanofiller,
on the properties of nitrile rubber composites was investigated.
The cure time of the compounds showed a decrease on incorporation
of NCC up to 5 phr and thereafter increased at higher NCC content.
The tensile strength, modulus and storage modulus increased with
the nanofiller content and declined after an optimum loading. The
solvent uptake and transport coefficients decreased with NCC
content, the minimum value being at 7.5 phr. The mechanism of
diffusion of toluene solvent through the nanocomposites was found
to be Fickian. Thermodynamic constants such as enthalpy and
activation energy were also evaluated. The dependence of various
properties on NCC content was corroborated with morphological
analysis using transmission electron microscopy.
References p.172-199, Publications based on the
work 200p.
Advisors/Committee Members: Bhagawan, S S.
Subjects/Keywords: Nanocomposite; Nitrile rubber; Mechanical properties; Dynamic mechanical properties; Transport properties; Nanoclay; Nanocalcium carbonate; Design of experiments; Optimization; Modelling
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APA (6th Edition):
Balachandran, M. (2012). Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites. (Thesis). Amrita Vishwa Vidyapeetham (University). Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/3919
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Balachandran, Meera. “Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites.” 2012. Thesis, Amrita Vishwa Vidyapeetham (University). Accessed January 20, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/3919.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Balachandran, Meera. “Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites.” 2012. Web. 20 Jan 2021.
Vancouver:
Balachandran M. Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites. [Internet] [Thesis]. Amrita Vishwa Vidyapeetham (University); 2012. [cited 2021 Jan 20].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/3919.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Balachandran M. Studies on acrylonitrile butadiene copolymer (Nitrile
Rubber) nano composites. [Thesis]. Amrita Vishwa Vidyapeetham (University); 2012. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/3919
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
24.
Glerum, Jacobus.
Mechanical properties of mammalian single smooth muscle cells9.
Degree: 1991, Erasmus University Medical Center
URL: http://hdl.handle.net/1765/40898
► textabstractWith the studies presented in this thesis it was attempted to achieve a discrimination between properties of smooth mus~ cle and of other components by…
(more)
▼ textabstractWith the studies presented in this thesis it was attempted to
achieve a discrimination between properties of smooth mus~
cle and of other components by measuring the passive and
active properties of single smooth muscle cells isolated from
both types of tissues.
At the onset of the study experiments were solely performed
on cells isolated from pig urinary bladders. which are quite
similar to those of the human urinary bladder. In a later phase
the study was extended to human uterine tissue fragments
obtained at planned Caesarean sections.
In order to achieve the goal of the study many practical and
technical problems had to be solved. Some of the technical aspects have been published in international journals as a
technical note or are embodied in the publications describing
the results obtained. :Many others, although of crucial import:
mce for the success of these experiments. especially in the
field of cell and muscle physiology. were considered to have
more practical and too little scientific value to be described
in separate publications or in this thesis
Subjects/Keywords: celbiology; mammalian; mechanical properties; smooth muscles; urinary bladder; urology; uterine tissues
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APA (6th Edition):
Glerum, J. (1991). Mechanical properties of mammalian single smooth muscle cells9. (Doctoral Dissertation). Erasmus University Medical Center. Retrieved from http://hdl.handle.net/1765/40898
Chicago Manual of Style (16th Edition):
Glerum, Jacobus. “Mechanical properties of mammalian single smooth muscle cells9.” 1991. Doctoral Dissertation, Erasmus University Medical Center. Accessed January 20, 2021.
http://hdl.handle.net/1765/40898.
MLA Handbook (7th Edition):
Glerum, Jacobus. “Mechanical properties of mammalian single smooth muscle cells9.” 1991. Web. 20 Jan 2021.
Vancouver:
Glerum J. Mechanical properties of mammalian single smooth muscle cells9. [Internet] [Doctoral dissertation]. Erasmus University Medical Center; 1991. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/1765/40898.
Council of Science Editors:
Glerum J. Mechanical properties of mammalian single smooth muscle cells9. [Doctoral Dissertation]. Erasmus University Medical Center; 1991. Available from: http://hdl.handle.net/1765/40898
25.
Wellen, Jeremy W.
Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms.
Degree: PhD, 2003, Worcester Polytechnic Institute
URL: etd-0430103-140128
;
https://digitalcommons.wpi.edu/etd-dissertations/232
► Research applications of nuclear magnetic resonance (NMR) span a broad range of fields and disciplines. The work presented in this dissertation attests to this fact.…
(more)
▼ Research applications of nuclear magnetic resonance (NMR) span a broad range of fields and disciplines. The work presented in this dissertation attests to this fact. Specifically, the research topics discussed in the body of this work employ NMR spectroscopy and imaging to characterize the water diffusion and NMR relaxation times ex vivo in rabbit Achilles tendon and, in a clinical setting, employ functional magnetic resonance imaging (fMRI) to investigate the behavior of different neural networks over a period of sustained activity. In the ex vivo rabbit Achilles tendon work, a series of studies were performed. First, the diffusion-time dependence of the water apparent diffusion coefficient (ADC) was characterized in a spectroscopic mode with the samples subjected to different states of tensile loading. The results of this study demonstrated: (1) the anisotropy of the diffusion of water through tendon; (2) the ADC is diffusion-time dependent; (3) the values of the ADC(tdif) curve increased with tensile loading; (4) a change at the short diffusion-time points that is consistent with the interpretation of a load-induced increase in the collagen fibril packing density; and (5) an increase in the water ADC at long diffusion times is hypothesized to be due to T1 editing. To further investigate these issues, another series of ex vivo rabbit Achilles tendon experiments was performed that employed NMR imaging to spatially characterize the water ADC, T1 and T2 relaxation time constants. As with the spectroscopic work, these studies were also conducted with the tendon samples subjected to different states of tensile loading. The results from these imaging experiments demonstrate: (1) two regions with distinct differences in signal intensity across the tendon: a thin region of high signal intensity at the peripheral rim of the tendon that encircles a region of low signal intensity in the central core of the tendon; (2) a higher diffusion anisotropy ratio in the tendon central core relative to the peripheral rim; (3) upon tensile loading, significant increases in the ADC of water in the peripheral rim region and a corresponding increase in a measure of the change in proton density in the rim region, consistent with the hypothesis that tensile loading causes extrusion of water from the core to the rim region of the tendon; (4) this water extrusion is not uniformly distributed throughout the tendon rim region; and (5) the long-diffusion-time ADC behavior is consistent with the T1 spin editing hypothesis of the spectroscopic work. From the clinical fMRI studies, an analysis method was presented for observing dynamic changes in brain regions involved in different neural network processes during a period of sustained activity. The results from these studies are consistent with the idea that over time, brain regions adapt to the given task demands through either recruitment or discharge of adjacent areas of tissue. These results also indicate that traditional analysis of block design fMRI studies may underestimate dynamic changes in…
Advisors/Committee Members: Karl G. Helmer, Committee Member, James F. Paskavitz, Committee Member, Ronald A. Cohen, Committee Member, George D. Pins, Committee Member.
Subjects/Keywords: diffusion; tendon; NMR; fMRI; Nuclear magnetic resonance; Tissues; Mechanical properties; Magnetic resonance imaging
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APA ·
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APA (6th Edition):
Wellen, J. W. (2003). Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms. (Doctoral Dissertation). Worcester Polytechnic Institute. Retrieved from etd-0430103-140128 ; https://digitalcommons.wpi.edu/etd-dissertations/232
Chicago Manual of Style (16th Edition):
Wellen, Jeremy W. “Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms.” 2003. Doctoral Dissertation, Worcester Polytechnic Institute. Accessed January 20, 2021.
etd-0430103-140128 ; https://digitalcommons.wpi.edu/etd-dissertations/232.
MLA Handbook (7th Edition):
Wellen, Jeremy W. “Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms.” 2003. Web. 20 Jan 2021.
Vancouver:
Wellen JW. Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms. [Internet] [Doctoral dissertation]. Worcester Polytechnic Institute; 2003. [cited 2021 Jan 20].
Available from: etd-0430103-140128 ; https://digitalcommons.wpi.edu/etd-dissertations/232.
Council of Science Editors:
Wellen JW. Characterization of soft-tissue response to mechanical loading using nuclear magnetic resonance (NMR) and functional magnetic resonance imaging (fMRI) of neuronal activity during sustained cognitive-stimulus paradigms. [Doctoral Dissertation]. Worcester Polytechnic Institute; 2003. Available from: etd-0430103-140128 ; https://digitalcommons.wpi.edu/etd-dissertations/232
Oregon State University
26.
Lusianti, Ratih E.
Removal of cryoprotectant with the use of a microseparation device.
Degree: MS, Chemical Engineering, 2010, Oregon State University
URL: http://hdl.handle.net/1957/18804
► Cryoprotectants (CPAs) such as glycerol and dimethyl sulfoxide (DMSO) are commonly used during cryopreservation of cell based therapeutics. Although these additives are beneficial during freezing,…
(more)
▼ Cryoprotectants (CPAs) such as glycerol and dimethyl sulfoxide (DMSO) are commonly used during cryopreservation of cell based therapeutics. Although these additives are beneficial during freezing, it is often desirable to remove them before infusion into a patient. Currently, the most common method for CPA removal is by centrifugation. This method is time consuming, labor intensive, and can also lead to significant cell losses. In this study, we investigate the possible use of a microseparation device for removal of CPAs from red blood cell suspensions. A mathematical model was developed to predict the CPA removal performance of the device and cell volume changes during the process. Experiments to ascertain the permeability
properties of several different types of membranes of interest were conducted using the device. The resulting experimental values were then incorporated into the model to make CPA removal predictions. To assess the accuracy of the model
predictions, glycerol removal experiments from solutions without red blood cells were carried out. Through comparison of the experimental data and the model predictions, it was found that the model could accurately predict CPA removal for membranes with sufficiently small pores where mass transfer is dominated by diffusion; but in membranes with larger pores where mass transfer is dominated by pressure driven flow, the model predicted values that are lower than what was obtained through experiments. The reason for this effect is the pressure discrepancy that was found between the pressure drop recorded during the experiment and the model predicted pressure drop. The model predicted pressure drop assumes ideal fluid flow condition whereas the actual conditions during the experiment indicates the presence of air bubbles trapped inside the channels, obstructing the flow of fluid and possibly altering the surface area available for mass transfer. Parametric studies using model simulations on the CPA removal performance of the membranes with smaller pores were conducted. Through parametric studies, CPA removal trends and cell volume changes during the process using the membranes of interest were better understood. The information gained from this study is useful for designing the next prototype of the microseparation device as well as for developing an optimal CPA removal protocol for red blood cell suspensions.
Advisors/Committee Members: Higgins, Adam Z. (advisor), Jovanovic, Goran (committee member).
Subjects/Keywords: Cryopreservation of organs; tissues; etc.
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APA (6th Edition):
Lusianti, R. E. (2010). Removal of cryoprotectant with the use of a microseparation device. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/18804
Chicago Manual of Style (16th Edition):
Lusianti, Ratih E. “Removal of cryoprotectant with the use of a microseparation device.” 2010. Masters Thesis, Oregon State University. Accessed January 20, 2021.
http://hdl.handle.net/1957/18804.
MLA Handbook (7th Edition):
Lusianti, Ratih E. “Removal of cryoprotectant with the use of a microseparation device.” 2010. Web. 20 Jan 2021.
Vancouver:
Lusianti RE. Removal of cryoprotectant with the use of a microseparation device. [Internet] [Masters thesis]. Oregon State University; 2010. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/1957/18804.
Council of Science Editors:
Lusianti RE. Removal of cryoprotectant with the use of a microseparation device. [Masters Thesis]. Oregon State University; 2010. Available from: http://hdl.handle.net/1957/18804
RMIT University
27.
Mustapa, I.
Biocomposites including nano-scale dispersed phase and polymers from renewable resources.
Degree: 2014, RMIT University
URL: http://researchbank.rmit.edu.au/view/rmit:160820
► Poly(lactic acid) (PLA) was physically modified by filling with an inorganic additive, natural fibres as well as with a tributyl citrate (TBC). PLA composites were…
(more)
▼ Poly(lactic acid) (PLA) was physically modified by filling with an inorganic additive, natural fibres as well as with a tributyl citrate (TBC). PLA composites were prepared with a film stacking method and analysed by scanning electron microscopy (SEM), thermogravimetry (TGA), thermomechanometry and differential scanning calorimetry (DSC) to investigate the physical and mechanical properties of the hybrid composites. PLA composites reinforced with hemp fibres in combination with nanosilica are thermally stable as the maximum rate of weight loss of the composites shifted to the highest temperature observed in TGA results. Dynamic mechanical properties of PLA composites showed that the reinforcement of hemp fibre and nanosilica strongly affected the mechanical properties of the composites. The highest storage modulus improvements were reached by addition of hemp fibre and nanosilica without plasticiser. An increase in storage modulus monitored in the temperature region from 70 to 100 °C reflected an increase in structural stiffness due to recrystallisation activity in the composites. The addition of TBC reduced the modulus though initiated the crystallisation on cooling, enhanced the nucleating ability of the fillers and chain mobility in PLA composites. The melting and crystallisation behaviour of PLA composites was explored with non isothermal DSC at various scanning rates. The characteristics of the crystallisation and melting behaviour of PLA composites were explained by the slow rate of crystallisation and recrystallisation, which is in agreement with DMA results. Non-isothermal crystallization kinetics shows that the crystallization rate of PLA composites was higher than of neat PLA and further increased with presence of TBC, indicating that the addition of plasticiser and nucleating agents enhanced the transportation ability of polymer chains. SEM revealed a good distribution of nanosilica for composites with and without TBC. A great transfer of stress between hemp fibres and PLA nanosilica matrix resulted in improved of physical and mechanical properties as evidenced by DMA and DSC results.
Subjects/Keywords: Fields of Research; Biodegradable Polymer; Mechanical properties; Thermal properties; Crystallization; Morphology; Nucleation
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APA (6th Edition):
Mustapa, I. (2014). Biocomposites including nano-scale dispersed phase and polymers from renewable resources. (Thesis). RMIT University. Retrieved from http://researchbank.rmit.edu.au/view/rmit:160820
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mustapa, I. “Biocomposites including nano-scale dispersed phase and polymers from renewable resources.” 2014. Thesis, RMIT University. Accessed January 20, 2021.
http://researchbank.rmit.edu.au/view/rmit:160820.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mustapa, I. “Biocomposites including nano-scale dispersed phase and polymers from renewable resources.” 2014. Web. 20 Jan 2021.
Vancouver:
Mustapa I. Biocomposites including nano-scale dispersed phase and polymers from renewable resources. [Internet] [Thesis]. RMIT University; 2014. [cited 2021 Jan 20].
Available from: http://researchbank.rmit.edu.au/view/rmit:160820.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mustapa I. Biocomposites including nano-scale dispersed phase and polymers from renewable resources. [Thesis]. RMIT University; 2014. Available from: http://researchbank.rmit.edu.au/view/rmit:160820
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Brno University of Technology
28.
Haluza, Jakub.
Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons.
Degree: 2019, Brno University of Technology
URL: http://hdl.handle.net/11012/7249
► Diploma thesis in the first part deals with the production, properties and application of compacted graphite iron. After then calculation model which is used in…
(more)
▼ Diploma thesis in the first part deals with the production,
properties and application of compacted graphite iron. After then calculation model which is used in ProCAST software for the predicting
mechanical and structural
properties of compacted graphite iron is presented and differences between versions 2010 and 2011 are shown. The last part of the thesis deals with simulation of
mechanical and structural
properties on the test specimen and real casting, which is poured in Heunisch foundry Ltd. and results of the simulation and measured values are compared.
Advisors/Committee Members: Krutiš, Vladimír (advisor), Bouška, Ondřej (referee).
Subjects/Keywords: vermikulární litina; vlastnosti; simulace mechanických vlastností; Compacted Graphite Iron; Properties; Simulation of Mechanical Properties
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APA (6th Edition):
Haluza, J. (2019). Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/7249
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Haluza, Jakub. “Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons.” 2019. Thesis, Brno University of Technology. Accessed January 20, 2021.
http://hdl.handle.net/11012/7249.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Haluza, Jakub. “Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons.” 2019. Web. 20 Jan 2021.
Vancouver:
Haluza J. Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons. [Internet] [Thesis]. Brno University of Technology; 2019. [cited 2021 Jan 20].
Available from: http://hdl.handle.net/11012/7249.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Haluza J. Numerická simulace mechanických vlastností grafitických litin: Numerical simulation of mechanical properties of cast irons. [Thesis]. Brno University of Technology; 2019. Available from: http://hdl.handle.net/11012/7249
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
New Jersey Institute of Technology
29.
Muley, Sarang Vilas.
Electronic, optical, mechanical and thermoelectric properties of graphene.
Degree: PhD, Committee for the Interdisciplinary Program in Materials Science and Engineering, 2015, New Jersey Institute of Technology
URL: https://digitalcommons.njit.edu/dissertations/104
► Graphene, a two-dimensional allotrope of graphite with sp2 bonded carbon atoms, is arranged in honeycomb structure. Its quasi one-dimensional form is graphene nanoribbon (GNR).…
(more)
▼ Graphene, a two-dimensional allotrope of graphite with sp
2 bonded carbon atoms, is arranged in honeycomb structure. Its quasi one-dimensional form is graphene nanoribbon (GNR). Graphene related materials have been found to display excellent electronic, chemical,
mechanical properties along with uniquely high thermal conductivity, electrical conductivity and high optical transparency. With excellent electrical characteristics such as high carrier transport
properties, quantum Hall effect at room temperature and unusual magnetic
properties, graphene has applications in optoelectronic devices.
Electronically, graphene is a zero bandgap semiconductor making it essential to tailor its structure for obtaining specific band structure. Narrow GNRs are known to open up bandgap and found to exhibit variations for different chiralities i.e., armchair and zigzag. Doping graphene, with p- or n- type elements, is shown to exhibit bandgap in contrast to pristine graphene.
In this study, optical
properties including dielectric functions, absorption coefficient, transmittance, and reflectance, as a function of wavelength and incident energy, are studied. Refractive index and extinction coefficient of pristine graphene are presented. A key optical property in the infrared region, emissivity, is studied as a function of wavelength for various multilayered configurations having graphene as one of the constituent layers. Application of such a structure is in the fabrication of a Hot Electron Bolometer (a sensor that operates on the basis of temperature-dependent electrical resistance).
Graphene is found to have very high elastic modulus and intrinsic strength. Nanoindentation of graphene sheet is simulated to study the force versus displacement curves. Effects of variation of diameter of indenter, speed of indentation and number of layers of graphene on the
mechanical properties are presented.
Shrinking size of electronic devices has led to an acute need for thermal management. This prompted the study of thermoelectric (TE) effects in graphene based systems. TE devices are finding applications in power generation and solid state refrigeration. This study involves analyzing the electronic, thermal and electrical transport
properties of these systems. Electronic thermal conductivity, of graphene based systems (κ
e), is found to be negligible as compared to its phonon-induced lattice thermal conduction (κ
p). Variations in κ
p of graphene and GN Rs are evaluated as a function of their width and length of their edges, chiralities, temperature, and number of layers. The interdependence of transport parameters, i.e., electrical conductivity (σ), thermoelectric power (TEP) or Seebeck coefficient (S), and κ of graphene are discussed. The thermoelectric performance of these materials is determined mainly by a parameter called Figure-of-Merit. Effective methods to optimize the value of Figure-of-Merit are explored. Reducing the thermal…
Advisors/Committee Members: N. M. Ravindra, Ken Keunhyuk Ahn, Michael R. Booty.
Subjects/Keywords: Electronic properties of graphene; Optical properties of graphene; Graphine nanoribbons study; Thermoelectric properties of graphene; Mechanical properties of graphene; Graphene; Materials Science and Engineering
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APA (6th Edition):
Muley, S. V. (2015). Electronic, optical, mechanical and thermoelectric properties of graphene. (Doctoral Dissertation). New Jersey Institute of Technology. Retrieved from https://digitalcommons.njit.edu/dissertations/104
Chicago Manual of Style (16th Edition):
Muley, Sarang Vilas. “Electronic, optical, mechanical and thermoelectric properties of graphene.” 2015. Doctoral Dissertation, New Jersey Institute of Technology. Accessed January 20, 2021.
https://digitalcommons.njit.edu/dissertations/104.
MLA Handbook (7th Edition):
Muley, Sarang Vilas. “Electronic, optical, mechanical and thermoelectric properties of graphene.” 2015. Web. 20 Jan 2021.
Vancouver:
Muley SV. Electronic, optical, mechanical and thermoelectric properties of graphene. [Internet] [Doctoral dissertation]. New Jersey Institute of Technology; 2015. [cited 2021 Jan 20].
Available from: https://digitalcommons.njit.edu/dissertations/104.
Council of Science Editors:
Muley SV. Electronic, optical, mechanical and thermoelectric properties of graphene. [Doctoral Dissertation]. New Jersey Institute of Technology; 2015. Available from: https://digitalcommons.njit.edu/dissertations/104
AUT University
30.
Anand, Gautam.
Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
.
Degree: AUT University
URL: http://hdl.handle.net/10292/10936
► Bioimpedance analysis (BIA) is a popular technique used in the monitoring of various physiological parameters like arterial oscillation, blood volume flow rate and cardiac output.…
(more)
▼ Bioimpedance analysis (BIA) is a popular technique used in the monitoring of various physiological parameters like arterial oscillation, blood volume flow rate and cardiac output. BIA is based on measuring the impedance of the tissue under test which reflects the dielectric behavior of the tissue along with the associated dynamics. This technique generally finds applications as single frequency BIA (SF-BIA) in the form of impedance cardiography (ICG) and impedance plethysmography (IPG), or multi-frequency BIA (MF-BIA) in the form of impedance spectroscopy and tomography.
Existing methods of hemodynamic monitoring employ SF-BIA (such as ICG) where a single frequency current is introduced into the tissue, and the obtained output is processed to estimate parameters like stroke volume, cardiac output, and pulse wave velocity (PWV). SF-BIA provides an approximate response of the volume changes and is unable to distinguish the impedance contributions of a single tissue domain from the overall measurements. This research aims at investigating the effect of blood flow-induced changes in the radial artery cross-section in the human forearm through MF-BIA. This offers a novel approach to analyze the multi-frequency impedance response related to blood flow in the peripheral arteries and relate the impedance changes to estimate the changes in the diameter.
The thesis presents a simulation model of the fat, muscle and artery tissue layers in a section of human forearm. The model, although assuming isotropic dielectric
properties for each tissue, aims at simulating the dielectric response of the tissue layers within the major portion of β dispersion frequency range – 1 kHz to 2 MHz. The main aim of this analysis was to understand the effect of pulsatile blood flow on the MF-BIA response, which was realized by simulating impedance measurements at three radial arterial diameters – 2.3 mm, 2.35 mm, and 2.4 mm. The results indicated a non-linearly decreasing behavior of the impedance spectra with increasing artery diameters, and a Cole-type response.
Moreover, a human forearm phantom was developed, to mimic the dielectric
properties of human
tissues, with the same tissue layers as the simulation model. A coaxial cylindrical sensor was developed and calibrated to estimate the dielectric
properties of liquid mixtures and the research identified blood can be simulated using 80% propylene glycol and 20% 4 M NaCl solution, muscle using 3.77% agar and 1.88% gelatine suspended in 0.3% NaCl solution with 18.8% propylene glycol and fat using a suspension of 5% agar in 0.05% NaCl solution. The phantom was tested for the impedance response at the three arterial diameters within the same frequency range and agreed with the simulation response.
Analytical modeling was undertaken to investigate, parametrically, the behavior of the system. Two approaches were undertaken – a parametric Debye-type modeling to estimate the impedance contribution from different layers and a more realistic Cole model to fit the response in terms of Cole parameters.…
Advisors/Committee Members: Lowe, Andrew (advisor), Al-Jumaily, Ahmed (advisor).
Subjects/Keywords: Bioimpedance;
Dielectric properties of tissues;
Hemodynamics;
simulation of human forearm
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APA (6th Edition):
Anand, G. (n.d.). Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
. (Thesis). AUT University. Retrieved from http://hdl.handle.net/10292/10936
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Anand, Gautam. “Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
.” Thesis, AUT University. Accessed January 20, 2021.
http://hdl.handle.net/10292/10936.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Anand, Gautam. “Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
.” Web. 20 Jan 2021.
Note: this citation may be lacking information needed for this citation format:
No year of publication.
Vancouver:
Anand G. Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
. [Internet] [Thesis]. AUT University; [cited 2021 Jan 20].
Available from: http://hdl.handle.net/10292/10936.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
Council of Science Editors:
Anand G. Multi-frequency Bioimpedance Variations in a Simulated Human Forearm
. [Thesis]. AUT University; Available from: http://hdl.handle.net/10292/10936
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
No year of publication.
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