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Dalhousie University
1.
Murray, Benedict.
Purposeful/Purposeless.
Degree: M. Arch., Department of Architecture, 2012, Dalhousie University
URL: http://hdl.handle.net/10222/14628 
► This thesis examines what makes a building valuable enough to keep regardless of what happens within it or where it is. A generic vacant lot…
(more)
▼ This thesis examines what makes a building valuable
enough to keep regardless of what happens within it or where it is.
A generic vacant lot in Dartmouth, N.S., ensures that these
qualities are derived primarily from the architecture rather than
its site. By housing three very different building programs, an
auto body shop, small school and church, the design is challenged
to become resilient to significant change. The thesis draws on
ideas of building permanency - polyvalencey and frame theory
(Leupen), as well as adaptability - building
layers and strategic
over-dimensioning (Brand). Valuable permanency is achieved by
creating a building that is both full of purpose and purposeless at
the same time. Furposefully, it is achieved through the use and
correct arrangement of common forms, spatial sizes, a diversity of
spatial types, as well as a high degree of self-maintenance of
climate and construction. The purposeless qualities of proportion,
craft and light help give the building its enduring
character.
Advisors/Committee Members: Brian Carter (external-examiner), Steve Parcell (graduate-coordinator), Brian Carter (thesis-reader), Emanuel Jannasch (thesis-reader), Susan Molesky (thesis-supervisor), Not Applicable (ethics-approval), Not Applicable (manuscripts), Not Applicable (copyright-release).
Subjects/Keywords: Building Layers
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APA (6th Edition):
Murray, B. (2012). Purposeful/Purposeless. (Masters Thesis). Dalhousie University. Retrieved from http://hdl.handle.net/10222/14628
Chicago Manual of Style (16th Edition):
Murray, Benedict. “Purposeful/Purposeless.” 2012. Masters Thesis, Dalhousie University. Accessed January 16, 2021.
http://hdl.handle.net/10222/14628.
MLA Handbook (7th Edition):
Murray, Benedict. “Purposeful/Purposeless.” 2012. Web. 16 Jan 2021.
Vancouver:
Murray B. Purposeful/Purposeless. [Internet] [Masters thesis]. Dalhousie University; 2012. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10222/14628.
Council of Science Editors:
Murray B. Purposeful/Purposeless. [Masters Thesis]. Dalhousie University; 2012. Available from: http://hdl.handle.net/10222/14628
University of Pretoria
2.
[No author].
Behaviour of cementitious subbase layers in bitumen
base road structures
.
Degree: 2009, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-08042009-115309/
► The process of designing cementitious layers (weakly and strongly cemented) against fatigue distress in road structures is well accepted. Research and field investigations with the…
(more)
▼ The process of designing cementitious
layers (weakly
and strongly cemented) against fatigue distress in road structures
is well accepted. Research and field investigations with the aid of
the Heavy Vehicle Simulator (HVS) revealed, however, that almost
all weakly cemented subbase
layers undergo non-traffic and
traffic¬associated cracking and eventually degradation of the
cemented material into a granular state (post-cracked phase). It is
therefore very important to analyse these
layers in the
post-cracked phase and to incorporate the results of this analysis
in the design, for both new and rehabilitation designs. The
investigations revealed that the rate of degradation of these
materials is largely dependent on traffic loading and the moisture
conditions within the pavement
layers. The purpose of this study is
to investigate the behaviour of weakly cemented subbase
layers in
road structures mainly under a bitumen base between 90 mm and 140
mm thick. This behaviour includes both pre-cracked and post-cracked
phases. It is shown that the fatigue life of bitumen base
layers is
mainly governed by the condition of the weakly cemented subbase
layers. In Chapter 1 a brief historical review is given of the
development of fatigue distress criteria of the cementitious
layers. It is shown that the maximum horizontal tensile strain at
the bottom of these
layers is the main distress criterion in the
pre-cracked phase. Unconfined compressive strength and durability
requirements are also discussed. Some aspects of the current design
methods are outlined in Chapter 2. The concept of equivalent
granular states in the post-¬cracked phase of cementitious
layers
was derived from HVS test findings. However, before this document
no behavioural prediction models were available to quantify
accurately the post-cracked state of these
layers. The actual
mechanisms of distress were also not clear. In Chapter 3, a
detailed investigations and analysis of ten dif¬ferent HVS tests at
four different sites in Natal are discussed. The purpose of the
analysis, is firstly to illustrate the powerful method of
full-scale accelerated HVS-type testing and secondly to indicate
the importance of the upper subbase layer, the initial condition of
the in-situ structure, the importance of water condi¬tions within
the pavement structure, and finally the different states of
behaviour of this type of road structure, including predictions of
future behaviour based on linear elastic theory. The
characteristics of the weakly cemented upper subbase layer are
shown to be of paramount importance in the final behaviour of these
structures. In Chapter 4 a method of analysing the behaviour of
mainly weakly cemented
layers in the post-cracked phase is
proposed. This method arises from the HVS testing discussed in
Chapter 3, and may be regarded as the most important improvement on
the current method discussed in Chapter 2. The analysis
incorporates the determination of the effective elastic moduli of
weakly cemented subbase
layers, including both the wet and the dry
periods…
Advisors/Committee Members: Prof P F Savage (advisor), Dr C R Freeme (advisor).
Subjects/Keywords: Subbase layers;
Cementitious layers;
Road structures;
UCTD
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2009). Behaviour of cementitious subbase layers in bitumen
base road structures
. (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-08042009-115309/
Chicago Manual of Style (16th Edition):
author], [No. “Behaviour of cementitious subbase layers in bitumen
base road structures
.” 2009. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://upetd.up.ac.za/thesis/available/etd-08042009-115309/.
MLA Handbook (7th Edition):
author], [No. “Behaviour of cementitious subbase layers in bitumen
base road structures
.” 2009. Web. 16 Jan 2021.
Vancouver:
author] [. Behaviour of cementitious subbase layers in bitumen
base road structures
. [Internet] [Masters thesis]. University of Pretoria; 2009. [cited 2021 Jan 16].
Available from: http://upetd.up.ac.za/thesis/available/etd-08042009-115309/.
Council of Science Editors:
author] [. Behaviour of cementitious subbase layers in bitumen
base road structures
. [Masters Thesis]. University of Pretoria; 2009. Available from: http://upetd.up.ac.za/thesis/available/etd-08042009-115309/
University of Pretoria
3.
De Beer, Morris.
Behaviour of
cementitious subbase layers in bitumen base road
structures.
Degree: Civil Engineering, 2009, University of Pretoria
URL: http://hdl.handle.net/2263/27004
► The process of designing cementitious layers (weakly and strongly cemented) against fatigue distress in road structures is well accepted. Research and field investigations with the…
(more)
▼ The process of designing cementitious
layers (weakly and
strongly cemented) against fatigue distress in road structures is
well accepted. Research and field investigations with the aid of
the Heavy Vehicle Simulator (HVS) revealed, however, that almost
all weakly cemented subbase
layers undergo non-traffic and
traffic¬associated cracking and eventually degradation of the
cemented material into a granular state (post-cracked phase). It is
therefore very important to analyse these
layers in the
post-cracked phase and to incorporate the results of this analysis
in the design, for both new and rehabilitation designs. The
investigations revealed that the rate of degradation of these
materials is largely dependent on traffic loading and the moisture
conditions within the pavement
layers. The purpose of this study is
to investigate the behaviour of weakly cemented subbase
layers in
road structures mainly under a bitumen base between 90 mm and 140
mm thick. This behaviour includes both pre-cracked and post-cracked
phases. It is shown that the fatigue life of bitumen base
layers is
mainly governed by the condition of the weakly cemented subbase
layers. In Chapter 1 a brief historical review is given of the
development of fatigue distress criteria of the cementitious
layers. It is shown that the maximum horizontal tensile strain at
the bottom of these
layers is the main distress criterion in the
pre-cracked phase. Unconfined compressive strength and durability
requirements are also discussed. Some aspects of the current design
methods are outlined in Chapter 2. The concept of equivalent
granular states in the post-¬cracked phase of cementitious
layers
was derived from HVS test findings. However, before this document
no behavioural prediction models were available to quantify
accurately the post-cracked state of these
layers. The actual
mechanisms of distress were also not clear. In Chapter 3, a
detailed investigations and analysis of ten dif¬ferent HVS tests at
four different sites in Natal are discussed. The purpose of the
analysis, is firstly to illustrate the powerful method of
full-scale accelerated HVS-type testing and secondly to indicate
the importance of the upper subbase layer, the initial condition of
the in-situ structure, the importance of water condi¬tions within
the pavement structure, and finally the different states of
behaviour of this type of road structure, including predictions of
future behaviour based on linear elastic theory. The
characteristics of the weakly cemented upper subbase layer are
shown to be of paramount importance in the final behaviour of these
structures. In Chapter 4 a method of analysing the behaviour of
mainly weakly cemented
layers in the post-cracked phase is
proposed. This method arises from the HVS testing discussed in
Chapter 3, and may be regarded as the most important improvement on
the current method discussed in Chapter 2. The analysis
incorporates the determination of the effective elastic moduli of
weakly cemented subbase
layers, including both the wet and the dry
periods…
Advisors/Committee Members: Prof P F Savage (advisor), Dr C R Freeme (advisor).
Subjects/Keywords: Subbase
layers; Cementitious
layers; Road
structures;
UCTD
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
De Beer, M. (2009). Behaviour of
cementitious subbase layers in bitumen base road
structures. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/27004
Chicago Manual of Style (16th Edition):
De Beer, Morris. “Behaviour of
cementitious subbase layers in bitumen base road
structures.” 2009. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://hdl.handle.net/2263/27004.
MLA Handbook (7th Edition):
De Beer, Morris. “Behaviour of
cementitious subbase layers in bitumen base road
structures.” 2009. Web. 16 Jan 2021.
Vancouver:
De Beer M. Behaviour of
cementitious subbase layers in bitumen base road
structures. [Internet] [Masters thesis]. University of Pretoria; 2009. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/2263/27004.
Council of Science Editors:
De Beer M. Behaviour of
cementitious subbase layers in bitumen base road
structures. [Masters Thesis]. University of Pretoria; 2009. Available from: http://hdl.handle.net/2263/27004
Texas A&M University
4.
Kuester, Matthew Scott.
Distributed Roughness Receptivity in a Flat Plate Boundary Layer.
Degree: PhD, Aerospace Engineering, 2014, Texas A&M University
URL: http://hdl.handle.net/1969.1/152606
► Surface roughness can affect boundary layer transition by acting as a receptivity mechanism for transient growth. Several experiments have investigated transient growth created by discrete…
(more)
▼ Surface roughness can affect boundary layer transition by acting as a receptivity mechanism for transient growth. Several experiments have investigated transient growth created by discrete roughness elements; however, very few experiments have studied transient growth initiated by distributed surface roughness. Some of the work in this field predicts a "shielding" effect, where smaller distributed roughness displaces the boundary layer away from the wall and shields larger roughness peaks from the incoming boundary layer.
This dissertation describes an experiment specifically designed to study the shielding effect. Three roughness configurations, a deterministic distributed roughness patch, a slanted rectangle, and the combination of the two, were manufactured using rapid prototyping and installed flush with the wall in a flat plate boundary layer. The main objective was to compare the wakes of the discrete roughness and the combined roughness to examine if the distributed roughness shields the discrete roughness. Naphthalene flow visualization and hotwire anemometry were used to characterize
the boundary layer in the wakes of the different roughness configurations.
For roughness Reynolds numbers (Re_(k)) between 113 and 230, the distributed roughness initiated small amplitude disturbances that underwent transient growth. The discrete roughness element created a pair of high- and low-speed streaks in the boundary layer at a sub-critical Reynolds number (Re_(k) = 151). At a higher Reynolds number (Re_(k) = 220), the discrete element created a turbulent wedge 15 boundary layer thicknesses downstream.
When the distributed roughness was added around the discrete roughness, the wake amplitude decreased at the sub-critical Reynolds number, and transition was delayed by two boundary layer thicknesses at the higher Reynolds number. The distributed roughness redirects energy from longer spanwise wavelength modes to shorter spanwise wavelength modes. The presence of the distributed roughness also decreased the growth rate of secondary instabilities in the roughness wake.
This dissertation documents the first detailed measurements of transient growth over streamwise-extended distributed roughness and demonstrates that the shielding effect has the potential to delay roughness-induced transition. The results from this experiment lay the ground work for future studies of roughness receptivity and transient growth.
Advisors/Committee Members: White, Edward B (advisor), Saric, William S (committee member), Bowersox, Rodney (committee member), Morrison, Gerald (committee member).
Subjects/Keywords: Boundary Layers; Roughness; Transition
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APA (6th Edition):
Kuester, M. S. (2014). Distributed Roughness Receptivity in a Flat Plate Boundary Layer. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/152606
Chicago Manual of Style (16th Edition):
Kuester, Matthew Scott. “Distributed Roughness Receptivity in a Flat Plate Boundary Layer.” 2014. Doctoral Dissertation, Texas A&M University. Accessed January 16, 2021.
http://hdl.handle.net/1969.1/152606.
MLA Handbook (7th Edition):
Kuester, Matthew Scott. “Distributed Roughness Receptivity in a Flat Plate Boundary Layer.” 2014. Web. 16 Jan 2021.
Vancouver:
Kuester MS. Distributed Roughness Receptivity in a Flat Plate Boundary Layer. [Internet] [Doctoral dissertation]. Texas A&M University; 2014. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1969.1/152606.
Council of Science Editors:
Kuester MS. Distributed Roughness Receptivity in a Flat Plate Boundary Layer. [Doctoral Dissertation]. Texas A&M University; 2014. Available from: http://hdl.handle.net/1969.1/152606
Oregon State University
5.
Westbrook, Lindsay A.
Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs.
Degree: MS, Animal Science, 2016, Oregon State University
URL: http://hdl.handle.net/1957/60092
► Flaxseed is a rich source of alpha-linolenic acid (ALA). Feeding laying hens flax seed can increase n-3 fatty acids content (FA) in eggs, thus increasing…
(more)
▼ Flaxseed is a rich source of alpha-linolenic acid (ALA). Feeding laying hens flax seed can increase n-3 fatty acids content (FA) in eggs, thus increasing human intake of n-3 FA. However, non-starch polysaccharides (NSP), which decreases digestibility of dietary lipids and proteins. Addition of carbohydrase enzymes to flax-based layer diets can alter the anti-nutritive effects of NSP. Three experiments were conducted to investigate the effect of dietary supplementation of flaxseed and carbohydrase enzyme on hen production performance, egg quality, egg and hen liver tissue FA composition, and foregut morphology in layer hens.
A total of seventy-two brown layer hens were assigned to one of four dietary treatments: corn-soybean based diet (Control), Control plus 10% flax (Diet 1), Diet 1 +0.05% carbohydrase enzyme (Diet 2), and Diet 1 + 0.1% carbohydrase enzyme (Diet 3). All diets were isocaloric and isonitrogenous. Hens received the dietary treatments for a total of 4 months. Hens fed Diet 1 exhibited a trend for highest egg hen day production among the four dietary treatments (P=0.09). Hen age led to a reduction in egg production in all four dietary treatments during the four month feeding trial (P<0.0001). Both egg weight and yolk weight were significantly higher in hens fed Diet 2 (P=0.008). During the six week storage period, egg weight and yolk weight were significantly higher in hens fed Diet 2 and Diet 3 (P=0.005, P=0.044) as compared to the Control. Hens receiving Diet 3 showed a trend for a high yolk pH (P=0.083), while Diet 3 displayed a significantly higher albumen pH (P<0.0001).
Egg fatty acids were influenced by diet composition. Linoleic acid (LA) and arachidonic acid (AA) were highest in Control eggs (P<0.0001). ALA was highest in eggs from hens fed Diet 3 (P=0.009). DHA was significantly increased in eggs from hens fed Diet 1, Diet 2, and Diet 3 (P<0.0001) relative to the Control. Total n-3 FA was highest in hens consuming Diet 3 (P<0.0001) (>1.7 fold-increase compared to Control). Total long chain (>20 carbons) n-3 FA concentrations were highest among eggs from hens fed Diets 1, 2, and 3 (P<.0001). Egg total lipids showed no significant difference among the four dietary treatments.
A significant increase in ALA content was observed in the liver of hens fed Diets 1 and 3 (P<.0001) relative to the Control diet. There was a significant increase in LA and AA in liver of hens fed the Control as compared to Diets 1, 2, and 3 (P<0.0001). Furthermore, total n-6 FA were also significantly higher in the Control and Diet 1, while there was a significant increase in total n-3 FA seen in fed receiving Diet 1, 2, and 3. Liver DHA (22:6 n-3) content in hens fed Diets 1, 2, and 3 increased by an average of 2.27% relative to the Control. As for long chain n-3, there was a significant increase in the liver of hens receiving Diets 1, 2, and 3 as compared to the Control. Hen liver total lipids were significantly higher in hens fed Diets 1, 2, and 3 (P=0.0009). There was a significant increase…
Advisors/Committee Members: Cherian, Gita (advisor), Gerd, Bobe (committee member).
Subjects/Keywords: Layers; Hens – Feeding and feeds
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APA ·
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Manager
APA (6th Edition):
Westbrook, L. A. (2016). Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/60092
Chicago Manual of Style (16th Edition):
Westbrook, Lindsay A. “Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs.” 2016. Masters Thesis, Oregon State University. Accessed January 16, 2021.
http://hdl.handle.net/1957/60092.
MLA Handbook (7th Edition):
Westbrook, Lindsay A. “Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs.” 2016. Web. 16 Jan 2021.
Vancouver:
Westbrook LA. Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs. [Internet] [Masters thesis]. Oregon State University; 2016. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1957/60092.
Council of Science Editors:
Westbrook LA. Enzyme Supplementation of Layer Hen Diets Containing Whole Flaxseed to Increase n-3 Fatty Acids in Chicken Eggs. [Masters Thesis]. Oregon State University; 2016. Available from: http://hdl.handle.net/1957/60092
Delft University of Technology
6.
Allred, Jennie (author).
Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach.
Degree: 2017, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:e075771f-a53f-4790-8bdc-673381e7664f
► Scientific investigation of paintings has been facilitated by the development of advanced non-de\-struc\-tive imaging methods. Characterization of painting stratigraphy traditionally requires extraction of small…
(more)
▼ Scientific investigation of paintings has been facilitated by the development of advanced non-de\-struc\-tive imaging methods. Characterization of painting stratigraphy traditionally requires extraction of small paint samples, thereby limiting its use to a few locations on a painting due to its destructive nature. Alternatively, non-destructive analysis of paint layer stratigraphy and structure across an entire painting often requires highly specialized and costly equipment, and/or the transport of priceless artworks. In addition, most methods are also typically limited to a localized point analysis. This document proposes an alternative method for the substructure examination of paintings using a mobile macro-XRF spectrometer and a stereographic approach with reduced step sizes. This is coupled with a novel data analysis method which will enable a global study of the topographical features of hidden paint layers. As a prototype to test the feasibility of the method, we utilized a two-layer test sample consisting of pastose bone black pigment on pastose lead white, with an aluminum substrate. High resolution 3D optical microscopy was utilized to establish a ground truth for the thicknesses of both paint layers. Through successful registration of MA-XRF scans obtained with varying detector geometries into a single hyrbid image, we were able to find a strong correlation between the quanitative height data obtained with optical microscopy and our hybrid XRF image. Our findings indicate that utilizing this approach for visualizing hidden paint layer topographies proves to be very promising. Coupled with novel data fusion algorithms and visualization techniques, additional insight about painterly technique can thus be gained by utilizing existing MA-XRF scanners to scan a painting in multiple orientations.
Materials Science & Engineering
Advisors/Committee Members: Dik, Joris (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: XRF; hidden paint layers; paintings
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APA (6th Edition):
Allred, J. (. (2017). Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:e075771f-a53f-4790-8bdc-673381e7664f
Chicago Manual of Style (16th Edition):
Allred, Jennie (author). “Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach.” 2017. Masters Thesis, Delft University of Technology. Accessed January 16, 2021.
http://resolver.tudelft.nl/uuid:e075771f-a53f-4790-8bdc-673381e7664f.
MLA Handbook (7th Edition):
Allred, Jennie (author). “Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach.” 2017. Web. 16 Jan 2021.
Vancouver:
Allred J(. Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Jan 16].
Available from: http://resolver.tudelft.nl/uuid:e075771f-a53f-4790-8bdc-673381e7664f.
Council of Science Editors:
Allred J(. Characterization of Hidden Paint Layer Topography Using a Stereographic XRF Approach. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:e075771f-a53f-4790-8bdc-673381e7664f
Delft University of Technology
7.
Redeker, F.R. (author).
Expected transport of cover layer material.
Degree: 1986, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:fdaa762a-3b90-46e4-98a7-e1a57c7cbd1c
► In 1982 the Netherlands Marine Technological Research (MaTS) organization requested the Coastal Engineering Group of the Department of Civil Engineering at the Delft University of…
(more)
▼ In 1982 the Netherlands Marine Technological Research (MaTS) organization requested the Coastal Engineering Group of the Department of Civil Engineering at the Delft University of Technology to conduct research on the behaviour of pipelines instalied on a sandy sea bottom. This research project was split in the following subprojects. A - Study of the scour around pipelines on a sandy bottom, and the possible resulting self-burial. B - Stresses in the pipeline during the development of free spans. C - Forces exerted by groundwater pressures, when partly or completely burried. D - Stability of cover layers. This report is concerned with the last of these sub-projects. The design of a cover layer can be split into three parts: - The overall lay-out of the cover layer. - The dimensions of the top-layer material. - The filter construction.
Hydraulic Engineering
Civil Engineering and Geosciences
Advisors/Committee Members: Bijker, E.W. (mentor).
Subjects/Keywords: cover layers
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APA (6th Edition):
Redeker, F. R. (. (1986). Expected transport of cover layer material. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:fdaa762a-3b90-46e4-98a7-e1a57c7cbd1c
Chicago Manual of Style (16th Edition):
Redeker, F R (author). “Expected transport of cover layer material.” 1986. Masters Thesis, Delft University of Technology. Accessed January 16, 2021.
http://resolver.tudelft.nl/uuid:fdaa762a-3b90-46e4-98a7-e1a57c7cbd1c.
MLA Handbook (7th Edition):
Redeker, F R (author). “Expected transport of cover layer material.” 1986. Web. 16 Jan 2021.
Vancouver:
Redeker FR(. Expected transport of cover layer material. [Internet] [Masters thesis]. Delft University of Technology; 1986. [cited 2021 Jan 16].
Available from: http://resolver.tudelft.nl/uuid:fdaa762a-3b90-46e4-98a7-e1a57c7cbd1c.
Council of Science Editors:
Redeker FR(. Expected transport of cover layer material. [Masters Thesis]. Delft University of Technology; 1986. Available from: http://resolver.tudelft.nl/uuid:fdaa762a-3b90-46e4-98a7-e1a57c7cbd1c
University of Waikato
8.
Jones, Mark Hedley.
The Electrical Properties of Interfacial Double Layers
.
Degree: 2016, University of Waikato
URL: http://hdl.handle.net/10289/10617
► When solids and liquids are brought together, interfacial double-layers are likely to form. They are too small to feel or see so their presence goes…
(more)
▼ When solids and liquids are brought together, interfacial double-
layers are likely to form. They are too small to feel or see so their presence goes mostly unnoticed at the macroscopic level. A double layer is essentially a cluster of ions and/or charged molecules which are drawn from the body of a liquid to the surface of a solid. They are responsible for stabilising some of our most important fluids – blood, milk, paints, and inks. Without the protection of double-
layers, these mixtures clump and lose their fluidity.
This thesis examines both electricity generation from, and the electrical impedance of, interfacial double
layers.
Interfacial double-
layers represent the underlying theme of this work, which is broken into two parts. In part I, double
layers are used as a means of converting fluid-mechanical energy into electrical energy. My application for this is an energy harvester that could power electronic water meters. Domestic water meters are typically installed where electrical connection is not feasible. Harvesting energy at the meter may make electronic metering a feasible long-term solution. My findings show that double layer based energy harvesters are not efficient enough for this application yet. However, recent literature on the
subject suggests large gains in efficiency may be possible using more exotic materials. Such gains would allow a compact harvester to generate enough energy to operate an electronic meter with wireless transmitter.
Part II models the electrical impedance of electrodes submerged in electrolytes. Double-
layers contribute to the electrical impedance between solid-fluid interfaces. This work is important to designers of medical implants. Engineers use solutions of saline to mimic the environment experienced by their implants once implanted. This provides a way to test implant electronics without putting a patient at risk. A way of characterising the interface between electrodes and an electrolyte is to model it mathematically. An electrical model of an electrode-electrolyte interface was recently developed by my supervisor, Jonathan Scott. I use that model to compare electrodes placed in solutions of saline to those placed in a living animal. Measurements of the two show that no one concentration of saline matches the situation inside a live spinal cavity. I then create a low-cost electrolyte test solution that better matches the impedance measured in a living animal's spinal cavity.
Advisors/Committee Members: Scott, Jonathan B (advisor), Wilson, Marcus T (advisor).
Subjects/Keywords: Electrode modelling;
Interfacial double layers
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APA (6th Edition):
Jones, M. H. (2016). The Electrical Properties of Interfacial Double Layers
. (Doctoral Dissertation). University of Waikato. Retrieved from http://hdl.handle.net/10289/10617
Chicago Manual of Style (16th Edition):
Jones, Mark Hedley. “The Electrical Properties of Interfacial Double Layers
.” 2016. Doctoral Dissertation, University of Waikato. Accessed January 16, 2021.
http://hdl.handle.net/10289/10617.
MLA Handbook (7th Edition):
Jones, Mark Hedley. “The Electrical Properties of Interfacial Double Layers
.” 2016. Web. 16 Jan 2021.
Vancouver:
Jones MH. The Electrical Properties of Interfacial Double Layers
. [Internet] [Doctoral dissertation]. University of Waikato; 2016. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10289/10617.
Council of Science Editors:
Jones MH. The Electrical Properties of Interfacial Double Layers
. [Doctoral Dissertation]. University of Waikato; 2016. Available from: http://hdl.handle.net/10289/10617
University of Illinois – Urbana-Champaign
9.
Chiang, Jerry T.
Providing availability in the lower layers of a wireless network: philosophies and case studies.
Degree: PhD, 1200, 2012, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/29432
► Availability, together with confidentiality and integrity, form the basic concepts of information security. Indeed, a device, protocol, or network can enjoy the highest level of…
(more)
▼ Availability, together with confidentiality and integrity, form the basic concepts of information security. Indeed, a device, protocol, or network can enjoy the highest level of confidentiality and integrity, but still be of very little value to its clients if it is not available. In this dissertation, I consider the availability of wireless networks, which have permeated into almost every aspect of our daily life, from entertainment such as online games to utility infrastructure such as smart grids. A faulty entity can disrupt the connectivity
offered by the lower
layers of a wireless network and interrupt the provided services; thus, network availability in the lower
layers is essential both to prevent inconveniences and to reliably provide critical services.
This dissertation considers three major philosophies that aim to provide availability by defending against denial-of-service (DoS) attacks at the lower
layers. Specifically, a network can
1. detect misbehaviors to eliminate DoS attacks;
2. enforce fairness to mitigate DoS attacks; or
3. adopt randomization to escape DoS attacks.
For each philosophy, this dissertation presents a case study. I present a location verification protocol at the physical (PHY) layer that detects misbehavior in order to provide reliable position-based services. I also present a transport layer protocol that mitigates the flooding attack by enforcing Transport Control Protocal (TCP) fairness. I then present a flooding protocol that uses randomness at the PHY layer to escape from the jamming attack.
Advisors/Committee Members: Hu, Yih-Chun (advisor), Kumar, P.R. (committee member), Vaidya, Nitin H. (committee member), Borisov, Nikita (committee member).
Subjects/Keywords: availability; lower layers; wireless networks
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APA (6th Edition):
Chiang, J. T. (2012). Providing availability in the lower layers of a wireless network: philosophies and case studies. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/29432
Chicago Manual of Style (16th Edition):
Chiang, Jerry T. “Providing availability in the lower layers of a wireless network: philosophies and case studies.” 2012. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed January 16, 2021.
http://hdl.handle.net/2142/29432.
MLA Handbook (7th Edition):
Chiang, Jerry T. “Providing availability in the lower layers of a wireless network: philosophies and case studies.” 2012. Web. 16 Jan 2021.
Vancouver:
Chiang JT. Providing availability in the lower layers of a wireless network: philosophies and case studies. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2012. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/2142/29432.
Council of Science Editors:
Chiang JT. Providing availability in the lower layers of a wireless network: philosophies and case studies. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2012. Available from: http://hdl.handle.net/2142/29432
10.
Perkins, Sabina.
Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes.
Degree: MS, 2019, University of New Hampshire
URL: https://scholars.unh.edu/thesis/1306
► Cyanobacteria blooms take different forms: surface scums, subsurface epilimnetic blooms, benthic mats, and in some lakes, metalimnetic layers. There is limited field research on…
(more)
▼ Cyanobacteria blooms take different forms: surface scums, subsurface epilimnetic blooms, benthic mats, and in some lakes, metalimnetic
layers. There is limited field research on the seasonal behavior of metalimnetic
layers and the contribution of layer-produced cyanotoxins to the overall toxin profile of New Hampshire lakes. Three lakes in New Hampshire were monitored monthly pre-summer stratification through post-fall mixis in 2018, tracking the formation and persistence of deep-water cyanobacteria
layers and the physical/chemical/light environments where they were found. Cyanobacteria abundance and dominance were quantified through cell counts using an Imaging Flow Cytobot (IFCB) and with phycocyanin fluorescence estimates. Persistent, nearly monospecific populations of Planktothrix isothrix were detected in the metalimnion of all three lakes multiple years in a row, despite differing lake size, trophic status, and ecoregion. The
layers appeared to migrate up from the sediments, finding a depth with high nutrients, thermal stability, and low light levels that still allowed for photosynthesis. The levels of microcystin toxin were measured in both the surface and cyanobacteria layer and although we found overall low levels of microcystin in the lakes, surface microcystin levels were often higher than samples collected from the dense accumulations of cyanobacteria in the metalimnion. A partial least squares regression suggests microcystin levels are more related to toxin-producing species of cyanobacteria other than the Planktothrix isothrix found dominating the layer samples in all the lakes monitored. This raises the possibility that the dominant strain found in the metalimnetic
layers may not produce microcystin or did not experience conditions in the 2018 growing season that favored the production of microcystin. While these dense Planktothrix isothrix
layers did not appear to be producing microcystin at levels considered harmful to human health, we did not test for other toxins that Planktothrix sp. are known to produce and therefore cannot say that these
layers do not represent a human health risk.
Advisors/Committee Members: Jeff Schloss, James F Haney, Shane Bradt.
Subjects/Keywords: cyanobacteria; Metalimnetic Layers; Microcystin; Planktothrix
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APA (6th Edition):
Perkins, S. (2019). Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes. (Thesis). University of New Hampshire. Retrieved from https://scholars.unh.edu/thesis/1306
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):
Perkins, Sabina. “Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes.” 2019. Thesis, University of New Hampshire. Accessed January 16, 2021.
https://scholars.unh.edu/thesis/1306.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Perkins, Sabina. “Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes.” 2019. Web. 16 Jan 2021.
Vancouver:
Perkins S. Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes. [Internet] [Thesis]. University of New Hampshire; 2019. [cited 2021 Jan 16].
Available from: https://scholars.unh.edu/thesis/1306.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Perkins S. Going beneath the surface: The ecology of metalimnetic cyanobacteria layers in three New Hampshire Lakes. [Thesis]. University of New Hampshire; 2019. Available from: https://scholars.unh.edu/thesis/1306
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Virginia Tech
11.
Hartley, Ashton Elizabeth.
An Architectural Response to Movement.
Degree: M. Arch., Architecture, 2011, Virginia Tech
URL: http://hdl.handle.net/10919/31762
► In an effort to bolster Old Town Alexandria Virginia's burgeoning reputation as a mecca for the arts, I chose to design a dance center, set…
(more)
▼ In an effort to bolster Old Town Alexandria Virginia's burgeoning reputation as a mecca for the arts, I chose to design a dance center, set in what is currently a large parking lot adjacent to King Street's terminus at the Potomac River. Given the importance of movement to my site, especially in terms of pedestrians and the Potomac River, a dance center is a fitting building type.
To aid in crafting a cohesive building that spoke to both the demands of the site and the programmatic needs of a dance center, I looked to movement as the answer to all design quandaries: movement as thesis. I developed a stepped parti- a concept informed by strategies to invite, accommodate, and glorify movement. All elements of the building reinforce this parti to create a holistic building. The building follows the ascension of a primary staircase, and is supported by a multitude of columns, simultaneously reminiscent of a corps de ballet and an enchanted forest, both staples in the classical story ballet.
Advisors/Committee Members: Piedmont-Palladino, Susan C. (committeechair), Feuerstein, Marcia F. (committee member), Emmons, Paul F. (committee member).
Subjects/Keywords: movement layers transparency circulation
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APA (6th Edition):
Hartley, A. E. (2011). An Architectural Response to Movement. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/31762
Chicago Manual of Style (16th Edition):
Hartley, Ashton Elizabeth. “An Architectural Response to Movement.” 2011. Masters Thesis, Virginia Tech. Accessed January 16, 2021.
http://hdl.handle.net/10919/31762.
MLA Handbook (7th Edition):
Hartley, Ashton Elizabeth. “An Architectural Response to Movement.” 2011. Web. 16 Jan 2021.
Vancouver:
Hartley AE. An Architectural Response to Movement. [Internet] [Masters thesis]. Virginia Tech; 2011. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10919/31762.
Council of Science Editors:
Hartley AE. An Architectural Response to Movement. [Masters Thesis]. Virginia Tech; 2011. Available from: http://hdl.handle.net/10919/31762
Virginia Tech
12.
Houck, Christopher A.
Hide and Seek: An Architecture of Layers.
Degree: M. Arch., Architecture, 2013, Virginia Tech
URL: http://hdl.handle.net/10919/51791
► This project is an elementary school located in a suburban area outside of Williamsburg, Virginia. The building is sited on an eight acre plot of…
(more)
▼ This project is an elementary school located in a suburban area outside of Williamsburg, Virginia. The building is sited on an eight acre plot of wooded land and is designed for 100 students. A playground is designed as a counterpart to the school.
A design approach which resembles the layering of space is developed through the drawings. The experience of these spaces establishes a dialogue between building and student likened to a game of hide and seek.
Advisors/Committee Members: Rott, Hans Christian (committeechair), Gartner, Howard Scott (committee member), Thompson, Steven R. (committee member).
Subjects/Keywords: architecture; elementary school; layers; playground
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Manager
APA (6th Edition):
Houck, C. A. (2013). Hide and Seek: An Architecture of Layers. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/51791
Chicago Manual of Style (16th Edition):
Houck, Christopher A. “Hide and Seek: An Architecture of Layers.” 2013. Masters Thesis, Virginia Tech. Accessed January 16, 2021.
http://hdl.handle.net/10919/51791.
MLA Handbook (7th Edition):
Houck, Christopher A. “Hide and Seek: An Architecture of Layers.” 2013. Web. 16 Jan 2021.
Vancouver:
Houck CA. Hide and Seek: An Architecture of Layers. [Internet] [Masters thesis]. Virginia Tech; 2013. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10919/51791.
Council of Science Editors:
Houck CA. Hide and Seek: An Architecture of Layers. [Masters Thesis]. Virginia Tech; 2013. Available from: http://hdl.handle.net/10919/51791
Stellenbosch University
13.
Cloete, Romei Christeline.
Fatigue performance of seals.
Degree: MSc, Civil Engineering, 2015, Stellenbosch University
URL: http://hdl.handle.net/10019.1/97944
► ENGLISH ABSTRACT: Thin bituminous surfacings, in particular sprayed seals, are used quite extensively in various countries because they provide a low cost alternative to conventional…
(more)
▼ ENGLISH ABSTRACT: Thin bituminous surfacings, in particular sprayed seals, are used quite extensively in various countries because they provide a low cost alternative to conventional asphalt. Seals furthermore provide an acceptable wearing course which guards the underlying pavement
layers from the harsh effects of traffic and the environment by preventing ingress of moisture. Seals also provide a safe road environment by offering adequate skid resistance and noise reduction during its lifetime.
Evaluating the fatigue performance of thin surfacings is a challenging and complex task. Back calculation of the modulus of a thin surfacing layer has always been difficult because the deflections measured at various distances of the load centre and in the load centre contained little to no information on the deformation of the thin top layer itself.
The main objective of this research study is to characterize the fatigue performance of various types of seals sampled from existing road pavements across South Africa, taking into account different variables such as ages, climatic zones and traffic history. The characterisation of the fatigue of these sampled seals was carried out by developing a bi-layer system consisting of the sampled seal and a fast-cast polyurethane composite beam and subjecting to flexural bending in the four point bending beam apparatus, following the guideline for fatigue testing of Hot Mix Asphalt (HMA).
The test parameters and results are analysed in terms of fatigue and master curves obtained. It is understood that the apparatus affords an insight on the mechanism of fatigue failure of beam specimens by carrying out bending tests with alternating strain and stress amplitudes. The test approach yielded fatigue results for the composite system, which required a direct beam theory solution set-up in MATLAB, to extract the fatigue results of only the seals.
It was found that the conventional fatigue test criterion of fifty (50) percent reduction in initial flexural stiffness was only applicable for Single Seals, after various fatigue criteria were investigated. For Cape Seals the fatigue criteria was defined as fourty (40) percent reduction in initial flexural stiffness, whereas for Double Seals this failure criteria was significantly lower at twenty (20) percent reduction in initial flexural stiffness.
It was furthermore found that Single and Cape Seals imitated the behaviour of a uniform mix, similar to HMA and hence failed at a higher fatigue criterion. Double Seals however had a less uniform mix behaviour which subscribed to a reduced or lower fatigue criterion.
The influence of the variables on the outcome of fatigue was investigated by considering the effect of the single variables, combination of variables and the interaction between variables. For Single Seals it was found that the thickness of the seal, the applied loading strain and the age provided most significance on the outcome of fatigue. Similarly, for Cape Seals, the thickness and age provided most significance, but with the added…
Advisors/Committee Members: Jenkins, Kim J., Stellenbosch University. Faculty of Engineering. Dept. of Civil Engineering..
Subjects/Keywords: Sprayed seals; Pavement layers; Thin surfacing layers; UCTD
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APA (6th Edition):
Cloete, R. C. (2015). Fatigue performance of seals. (Masters Thesis). Stellenbosch University. Retrieved from http://hdl.handle.net/10019.1/97944
Chicago Manual of Style (16th Edition):
Cloete, Romei Christeline. “Fatigue performance of seals.” 2015. Masters Thesis, Stellenbosch University. Accessed January 16, 2021.
http://hdl.handle.net/10019.1/97944.
MLA Handbook (7th Edition):
Cloete, Romei Christeline. “Fatigue performance of seals.” 2015. Web. 16 Jan 2021.
Vancouver:
Cloete RC. Fatigue performance of seals. [Internet] [Masters thesis]. Stellenbosch University; 2015. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10019.1/97944.
Council of Science Editors:
Cloete RC. Fatigue performance of seals. [Masters Thesis]. Stellenbosch University; 2015. Available from: http://hdl.handle.net/10019.1/97944
Oregon State University
14.
Cade, David Edmund.
Detection, classification and ecology of acoustic scattering layers.
Degree: MS, Ocean, Earth and Atmospheric Sciences, 2014, Oregon State University
URL: http://hdl.handle.net/1957/46925
► Acoustic scattering layers of biological origin have been observed for nearly 70 years across the world’s oceans. The organisms that comprise these layers are known…
(more)
▼ Acoustic scattering
layers of biological origin have been observed for nearly 70 years across the world’s oceans. The organisms that comprise these
layers are known to be important features in most oceanic ecosystems, providing a vital trophic link between small phytoplankton grazers and larger species. There are many aspects of their ecology, however, that remain poorly described. To address this research gap, an automatic layer detection algorithm was designed to identify scattering
layers based on their acoustic structure and their horizontal continuity. It classifies
layers into broad, unstructured background
layers, and high-energy, consistently organized, horizontally contiguous internal strata. The method was rigorously tested on data collected in three disparate ecosystems: the Gulf of California, Monterey Bay and the Bering Sea. With this new tool, scattering layer boundaries were identified in data from the Gulf of California. The bottom of the background layer in this region averaged 463 m depth during the day and 434 m at night, the bottom of the main migrating stratum averaged 333 m during the day and 54 m at night, and a consistent near-surface layer averaged 43 m during the day and 61 m at night. Average maximum rates of diel vertical migration were 8.6 cm/s when ascending and 6.9 cm/s when descending. Using CTD profile data in conjunction with layer boundary information, the hypothesis that scattering
layers in the Gulf of California are associated with specific oxygen values was tested. Several methods were employed to separate the influence of oxygen from other parameters including simple regressions, contingency tables, and logistic models. Suggestive evidence was found that shallow scattering
layers were associated with the thermocline, and midwater and deeper
layers were more associated with light, temperature or density than with oxygen, but no results were conclusive and a consistent physiological explanation of scattering layer depths below the thermocline could not be supported. I concluded that scattering layer depths and migration rates in the Gulf of California were broadly consistent with prior reports; however, evidence that scattering layer depths in the Gulf of California were associated with any one environmental parameter was lacking. Great care should be exercised when attempting to explain scattering layer depths through the lens of a single parameter, as covariates may offer alternate explanations and scattering layer depths are by nature complex features composed of individual organisms with a variety of physiological and non-physiological needs. The new tools I developed to describe the characteristics of scattering
layers, to automatically identify
layers based on their internal structure, and to analyze their relationship to the surrounding habitat contributed to our understanding of scattering
layers in the Gulf of California, and can contribute generally to future studies of these widespread and ecologically significant features.
Advisors/Committee Members: Benoit-Bird, Kelly J. (advisor), Heppell, Scott A. (committee member).
Subjects/Keywords: acoustic scattering layers; Echo scattering layers – Mexico – California, Gulf of
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APA (6th Edition):
Cade, D. E. (2014). Detection, classification and ecology of acoustic scattering layers. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/46925
Chicago Manual of Style (16th Edition):
Cade, David Edmund. “Detection, classification and ecology of acoustic scattering layers.” 2014. Masters Thesis, Oregon State University. Accessed January 16, 2021.
http://hdl.handle.net/1957/46925.
MLA Handbook (7th Edition):
Cade, David Edmund. “Detection, classification and ecology of acoustic scattering layers.” 2014. Web. 16 Jan 2021.
Vancouver:
Cade DE. Detection, classification and ecology of acoustic scattering layers. [Internet] [Masters thesis]. Oregon State University; 2014. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1957/46925.
Council of Science Editors:
Cade DE. Detection, classification and ecology of acoustic scattering layers. [Masters Thesis]. Oregon State University; 2014. Available from: http://hdl.handle.net/1957/46925
NSYSU
15.
Lin, Chi-kuan.
Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers.
Degree: Master, Electrical Engineering, 2015, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0706115-135844
► In this study, using the structure of dual piezoelectric layers:ZnO/AlN to fabricate the thin film bulk acoustic resonator (TFBAR).First seeding layer-titanium (Ti) and bottom electrode-platinum…
(more)
▼ In this study, using the structure of dual piezoelectric
layers:ZnO/AlN to fabricate the thin film bulk acoustic resonator (TFBAR).First seeding layer-titanium (Ti) and bottom electrode-platinum (Pt) were deposited by DC sputtering of a dual gun system.And then The piezoelectric thin films:AlN thin films and ZnO thin films were deposited by the RF reactive magnetron sputtering.To define the best parameters of the growth of piezoelectric AlN thin films and piezoelectric ZnO thin films using the X-ray diffraction and scanning electron microscopy.Finally, the dual piezoelectric
layers thin film bulk acoustic resonator (TFBAR) were fabricated by using the photolithographymethod to define the electrode and two-step ecth.
The result shows that AlN thin films can promote the acoustic velocity to promote the resonance frequency.The resonance frequency of tthin film bulk acoustic resonator (TFBAR) is 3.04GHz.Finally,by the method of reduce loss,the resonance frequency can be promoted to 3.04GHz.
Advisors/Committee Members: Ying-Chung Chen (committee member), Sheng-Yuan Chu (chair), Chien-Jung Huang (chair), Meng-Chyi Wu (chair), Yeong-Her Wang (chair).
Subjects/Keywords: Dual piezoelectric layers; TFBAR; ZnO; AlN; Etch
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APA (6th Edition):
Lin, C. (2015). Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0706115-135844
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):
Lin, Chi-kuan. “Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers.” 2015. Thesis, NSYSU. Accessed January 16, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0706115-135844.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lin, Chi-kuan. “Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers.” 2015. Web. 16 Jan 2021.
Vancouver:
Lin C. Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers. [Internet] [Thesis]. NSYSU; 2015. [cited 2021 Jan 16].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0706115-135844.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lin C. Fabrication and characteristics of thin film bulk acoustic resonator device using double piezoelectric layers. [Thesis]. NSYSU; 2015. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0706115-135844
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Pretoria
16.
[No author].
A structural design procedure for cement-treated layers
in pavements
.
Degree: 2013, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-05272013-130916/
► Cement-treated materials have been used successfully in road pavements since the thirties. In the past the research developments were mainly directed towards, and the emphasis…
(more)
▼ Cement-treated materials have been used successfully
in road pavements since the thirties. In the past the research
developments were mainly directed towards, and the emphasis during
design was mainly placed on material properties, with very little
attention being paid to thickness design. High-speed electronic
computers and the appropriate programs became available during the
sixties, and since then more effort has been devoted to the
requirements for a successful structural layout and the behaviour
of a pavement structure. This thesis, which is complementary to
these studies, discusses the structural design of pavements having
cementtreated
layers. Some of the design requirements have been
known for some time, three more have been added and finally a
design procedure is proposed and verified. Chapter 1 portrays the
development of structural pavement design theory. It indicates how
design procedures gradually became more extensive but also more
complex. A pavement design procedure which is based on layered
elastic theory fits into this development pattern and it has the
potential to comply with future requirements of structural design
procedures. The requirements for a structurally well-designed
cement-treated layer are summarized in Chapter 2. Some of these
were obtained from a literature survey and they include the
requirements that a cement-treated layer must be thick; it must be
built on a proper foundation while bearing in mind the principles
of a balanced design; and it must be designed to withstand the
heavy vehicles expected to travel on it. In the thesis attention is
paid to some of the other requirements, for example
non-trafficassociated and traffic-associated cracking, fatigue
behaviour, thermal stresses and the variability in the properties
of field- and laboratoryprepared materials. Some other requirements
which are mentioned but which will need further investigation, are
the material characterization, design criteria and the general
variability of construction materials. Cracking in cement-treated
materials is discussed in a somewhat original approach in Chapter 3
and it is pointed out that a clear distinction is necessary between
initial, that 1s non-traffic-associated, and traffic-associated
cracking. The occurrence of initial cracking must be accepted as a
fact and very little can be done to avoid it or prevent it from
occurring! Traffic-associated cracking in cement-treated
layers can
be prevented by an appropriate structural analysis and design. This
involves doing the analysis for an uncracked pavement and
thereafter making some increase in the maximum stress to
accommodate the stress increase caused by the initial,
non-traffic-associated, crack. Prismatic solid finite elements are
used to calculate the extent of the increase in the tensile stress
next to the initial crack (Chapter 4). The various ways of
modelling the pavement, and the accuracy of each of these methods,
are discussed and the use of the L-model is suggested and
justified. The vertical surface deflection and the increase in…
Advisors/Committee Members: Prof P F Savage (advisor), Prof C L Monismith (advisor).
Subjects/Keywords: Pavements;
Cement-treated layers;
Structural design;
UCTD
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to Zotero / EndNote / Reference
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APA (6th Edition):
author], [. (2013). A structural design procedure for cement-treated layers
in pavements
. (Doctoral Dissertation). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-05272013-130916/
Chicago Manual of Style (16th Edition):
author], [No. “A structural design procedure for cement-treated layers
in pavements
.” 2013. Doctoral Dissertation, University of Pretoria. Accessed January 16, 2021.
http://upetd.up.ac.za/thesis/available/etd-05272013-130916/.
MLA Handbook (7th Edition):
author], [No. “A structural design procedure for cement-treated layers
in pavements
.” 2013. Web. 16 Jan 2021.
Vancouver:
author] [. A structural design procedure for cement-treated layers
in pavements
. [Internet] [Doctoral dissertation]. University of Pretoria; 2013. [cited 2021 Jan 16].
Available from: http://upetd.up.ac.za/thesis/available/etd-05272013-130916/.
Council of Science Editors:
author] [. A structural design procedure for cement-treated layers
in pavements
. [Doctoral Dissertation]. University of Pretoria; 2013. Available from: http://upetd.up.ac.za/thesis/available/etd-05272013-130916/
University of Pretoria
17.
[No author].
The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
.
Degree: 2011, University of Pretoria
URL: http://upetd.up.ac.za/thesis/available/etd-10262011-154519/
► Stratiform chromitite layers are peculiar to large layered mafic intrusions. The origin of these chromitite layers has been widely debated. Some petrologists suggested that the…
(more)
▼ Stratiform chromitite
layers are peculiar to large
layered mafic intrusions. The origin of these chromitite
layers has
been widely debated. Some petrologists suggested that the
layers
formed as a result of the mixing of two compositionally different
magmas whereas others suggest that the chromitite
layers formed
from changes in pressure. The former hypothesis is widely accepted,
and states that chromitite forms when a more evolved magma is
injected into the chamber occupied by a more primitive one. To
evaluate this hypothesis, a study has been conducted on the
silicate textures and major element geochemistry of the
silicate-rich
layers above and below the MG4 chromitite package in
the Critical Zone of the Rustenburg Layered Suite, part of the
Bushvel Complex in South Africa.The MG4 chromitite package consists
of several chromitite seamsseparated by silicate
layers.
Orthopyroxene and plagioclase (interstitial plagioclase) are
observed in large amounts throughout the silicate layer, with less
abundant clinopyroxene and some trace amounts of biotite.
Throughout the silicate-rich
layers above and below the MG4
chromitite
layers (MG4 pyroxenite), the orthopyroxene exhibits no
major compositional variation in major elements (Mg#= 1.15-1.25).
This is also observed in the clinopyroxene composition throughout
the study area. However, plagioclase, which dominates the lower
part of the stratigraphy, varies in composition with a decrease in
the calcium content (Ca= 0.8-0.5) and a simultaneous increase in
the sodium content (Na=0.2-0.5). These similarities between the
rocks above and below the MG4 chromitite
layers suggest that the
chromitite layer originated from a single magma or a mixture of two
magmas with similar composition. This model is supported by the
observed thin sections where orthopyroxene occurs as euhedral
grains throughout the section especially above the 63.13m depth
lying above the plagioclase –rich layer. Trace element analysis
further suggest that the magma that crystallized the
plagioclase-rich lower part mixed with the influx of new magma rich
in Mg to crystallize the rocks of the upper sequence dominated by
orthopyroxene, clinopyroxene and Na-rich
plagioclase.
Advisors/Committee Members: Dr J Roberts (advisor).
Subjects/Keywords: Chromitite layers;
South africa;
Bushveld complex;
UCTD
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
author], [. (2011). The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
. (Masters Thesis). University of Pretoria. Retrieved from http://upetd.up.ac.za/thesis/available/etd-10262011-154519/
Chicago Manual of Style (16th Edition):
author], [No. “The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
.” 2011. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://upetd.up.ac.za/thesis/available/etd-10262011-154519/.
MLA Handbook (7th Edition):
author], [No. “The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
.” 2011. Web. 16 Jan 2021.
Vancouver:
author] [. The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
. [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2021 Jan 16].
Available from: http://upetd.up.ac.za/thesis/available/etd-10262011-154519/.
Council of Science Editors:
author] [. The silicate mineralogy of the MG4 chromitite package
in the eastern part of the Bushveld complex, South
Africa
. [Masters Thesis]. University of Pretoria; 2011. Available from: http://upetd.up.ac.za/thesis/available/etd-10262011-154519/
Mississippi State University
18.
Marroquin Salvador, Michael Deivi.
Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets.
Degree: MS, Aerospace Engineering, 2017, Mississippi State University
URL: http://sun.library.msstate.edu/ETD-db/theses/available/etd-10132017-130812/
;
► With the growing threat of orbital debris impacts to space structures, the development of space shielding concepts has been a critical research topic. In…
(more)
▼ With the growing threat of orbital debris impacts to space structures, the development of space shielding concepts has been a critical research topic. In this study, numerical simulations of the hypervelocity impact response of stacked aluminum 6061-T6 sheets were performed to assess the effects of layering on penetration resistance. This work was initially motivated by set of experimental tests where a stack of four aluminum sheets of equal thickness was observed to have a higher hypervelocity ballistic resistance than a monolithic aluminum sheet with the same total thickness. A set of smoothed particle hydrodynamic simulations predicted a 40% increase in the ballistic limit for a 6-layer target compared to a monolithic sheet. In addition, the effect of variable sheet thickness and sheet ordering on the impact resistance was investigated, while still maintaining a constant overall thickness. A set of thin
layers in front of a thick layer generally lead to a higher predicted ballistic limit than the inverse configuration. This work demonstrates an increase in the performance of advanced space shielding structures associated with multi-layering. This suggests that it may be possible to dramatically improve the performance of such structures by tailoring the material properties, interfaces, and layering concepts.
Advisors/Committee Members: Thomas E. Lacy (chair), Charles U. Pittman Jr. (committee member), Gregory D. Olsen (committee member), Santanu Kundu (committee member).
Subjects/Keywords: hypervelocity impacts; multi-layers; smoothed particle hydrodynamics
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Chicago ·
MLA ·
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CSE |
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to Zotero / EndNote / Reference
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APA (6th Edition):
Marroquin Salvador, M. D. (2017). Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets. (Masters Thesis). Mississippi State University. Retrieved from http://sun.library.msstate.edu/ETD-db/theses/available/etd-10132017-130812/ ;
Chicago Manual of Style (16th Edition):
Marroquin Salvador, Michael Deivi. “Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets.” 2017. Masters Thesis, Mississippi State University. Accessed January 16, 2021.
http://sun.library.msstate.edu/ETD-db/theses/available/etd-10132017-130812/ ;.
MLA Handbook (7th Edition):
Marroquin Salvador, Michael Deivi. “Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets.” 2017. Web. 16 Jan 2021.
Vancouver:
Marroquin Salvador MD. Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets. [Internet] [Masters thesis]. Mississippi State University; 2017. [cited 2021 Jan 16].
Available from: http://sun.library.msstate.edu/ETD-db/theses/available/etd-10132017-130812/ ;.
Council of Science Editors:
Marroquin Salvador MD. Hypervelocity impact of spherical aluminum 2017-T4 projectiles on aluminum 6061-T6 multi-layered sheets. [Masters Thesis]. Mississippi State University; 2017. Available from: http://sun.library.msstate.edu/ETD-db/theses/available/etd-10132017-130812/ ;
University of Saskatchewan
19.
Lardner, Michael J 1987-.
Spatiotemporal Mapping of Electrochemical Diffusion Layers.
Degree: 2016, University of Saskatchewan
URL: http://hdl.handle.net/10388/7394
► Although pure electrochemical techniques can provide substantial knowledge about electrochemical reaction mechanisms, they lack the ability to provide direct molecular structure information about the species…
(more)
▼ Although pure electrochemical techniques can provide substantial knowledge about electrochemical reaction mechanisms, they lack the ability to provide direct molecular structure information about the species involved. This inability to extract molecular information can result in mechanistic ambiguity with respect to the identity of the reaction intermediates. This information can be obtained by coupling in situ spectroscopic methodologies with electrochemical techniques. This is known as spectroelectrochemistry.
A particularly problematic area of study with spectroelectrochemical techniques is the analysis of the mass transport of species within the diffusion layer of the electrode. The visualization of the diffusion layer surrounding electrodes allows for the unambiguous determination of electrode processes. However, a high degree of spatial and temporal resolution is needed as the diffusion layer in a typical electrochemical reaction extends to a thickness of hundreds of microns in tens of seconds.
While traditional infrared spectroelectrochemical techniques have been valuable for the study of electrochemical processes, they do not provide the spatial and/or the temporal resolution that is needed to examine the diffusion
layers produced at electrodes. This thesis focuses on the development of an IR technique that couples synchrotron based IR radiation (SIR) with electrochemistry, allowing for the concentrations of species present within the diffusion layer of an electrode to be mapped during an electrochemical reaction.
The reduction of ferricyanide and oxidation of hydroquinone (HQ) are used as test redox systems to study the ability of SIR to map electrochemical diffusion
layers. The resulting diffusion coefficients of ferricyanide, ferrocyanide, hydroquinone and benzoquinone are extracted using the IR method developed here and compared to those determined independently by hydrodynamic linear sweep voltammetry (HLSV). The diffusion coefficients of all species as determined by SIR diffusion layer mapping will be shown to be consistent with the diffusion coefficients determined by HLSV. This validates the ability of SIR diffusion layer mapping to monitor electrochemically generated diffusion
layers.
Advisors/Committee Members: Burgess, Ian, Urquhart, Stephen, McBeth, Joyce, Wilson, Lee.
Subjects/Keywords: Electrochemistry; Diffusion; synchrotron IR; Diffusion Layers
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lardner, M. J. 1. (2016). Spatiotemporal Mapping of Electrochemical Diffusion Layers. (Thesis). University of Saskatchewan. Retrieved from http://hdl.handle.net/10388/7394
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):
Lardner, Michael J 1987-. “Spatiotemporal Mapping of Electrochemical Diffusion Layers.” 2016. Thesis, University of Saskatchewan. Accessed January 16, 2021.
http://hdl.handle.net/10388/7394.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lardner, Michael J 1987-. “Spatiotemporal Mapping of Electrochemical Diffusion Layers.” 2016. Web. 16 Jan 2021.
Vancouver:
Lardner MJ1. Spatiotemporal Mapping of Electrochemical Diffusion Layers. [Internet] [Thesis]. University of Saskatchewan; 2016. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10388/7394.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lardner MJ1. Spatiotemporal Mapping of Electrochemical Diffusion Layers. [Thesis]. University of Saskatchewan; 2016. Available from: http://hdl.handle.net/10388/7394
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
20.
Tang, Jizhou.
A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers.
Degree: PhD, Petroleum Engineering, 2018, Texas A&M University
URL: http://hdl.handle.net/1969.1/173741
► Unconventional shale reservoirs have been the most recent production frontier in the United States. Optimization of the production of shale reservoirs depends greatly on hydraulic…
(more)
▼ Unconventional shale reservoirs have been the most recent production frontier in the United States. Optimization of the production of shale reservoirs depends greatly on hydraulic fracture treatment. In recent studies, strongly contrasting properties of multi-layered rocks and pervasively distributed weak interfaces become the primary factors in determining the propagation pathway of fractures, which further influences the fracture height growth and fracture geometry. Few of hydraulic fracture propagation models enable us to quantitatively estimate the fracture height containment or predict fracture geometry under the influence of multiple bedding planes. Therefore, development of a reliable and practical simulator for modeling fracture propagation that enables accurate prediction of the fracture height growth in multiple-layered shale formation is critical to efficient resource development.
In this dissertation, I have developed a coupled three-dimensional hydraulic fracture propagation model considering the effects of bedding planes. In this model, a fully three-dimensional displacement discontinuity method is used to model the rock deformation. The advantage of this approach is that it addresses both the mechanical interaction between hydraulic fractures and weak bedding planes in three-dimensional space and the physical mechanism of slippage along weak bedding planes. Fluid flow governed by finite difference methodology considers the flow in both vertical fractures and opening bedding planes. An iterative algorithm is used to couple fluid flow and rock deformation. Comparison between the developed model and the PKN model showed good agreement. Analysis of different fracture geometry and sensitivity analysis of different parameters are conducted to investigate their impacts on the opening of vertical fractures and bedding planes, and also the shear sliding along the bedding planes. A width jump, created along the vertical fracture when the vertical fracture penetrates the bedding plane, is regarded as a primary mechanism of fracture height containment. Both widths of fracture segments and shear sliding along the bedding plane are positively related with the distance between the injection source and the bedding plane segment. Higher formation Young’s modulus can restrict the opening of bedding plane and retard the fluid percolation into the bedding plane. Smaller fracture spacing gives rise of the opening reduction of the fracture segments. Our model enables us to provide a critical insight for the selection of the proppant grain size range and assessment of the required pumping rate to obtain the required width at both junction and intersected bedding plane.
Advisors/Committee Members: Wu, Kan (advisor), Ehlig-Economides, Christine (committee member), Valko, Peter (committee member), Duan, Benchun (committee member).
Subjects/Keywords: Hydraulic Fracture Propagation Model; Bedding Layers
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Tang, J. (2018). A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/173741
Chicago Manual of Style (16th Edition):
Tang, Jizhou. “A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers.” 2018. Doctoral Dissertation, Texas A&M University. Accessed January 16, 2021.
http://hdl.handle.net/1969.1/173741.
MLA Handbook (7th Edition):
Tang, Jizhou. “A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers.” 2018. Web. 16 Jan 2021.
Vancouver:
Tang J. A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers. [Internet] [Doctoral dissertation]. Texas A&M University; 2018. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/1969.1/173741.
Council of Science Editors:
Tang J. A Coupled Three-Dimensional Hydraulic Fracture Propagation Model Accounting for the Effect of Bedding Layers. [Doctoral Dissertation]. Texas A&M University; 2018. Available from: http://hdl.handle.net/1969.1/173741
University of Pretoria
21.
Jolayemi, Olutola O.
The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa.
Degree: Geology, 2011, University of Pretoria
URL: http://hdl.handle.net/2263/29072
► Stratiform chromitite layers are peculiar to large layered mafic intrusions. The origin of these chromitite layers has been widely debated. Some petrologists suggested that the…
(more)
▼ Stratiform chromitite
layers are peculiar to large
layered mafic intrusions. The origin of these chromitite
layers has
been widely debated. Some petrologists suggested that the
layers
formed as a result of the mixing of two compositionally different
magmas whereas others suggest that the chromitite
layers formed
from changes in pressure. The former hypothesis is widely accepted,
and states that chromitite forms when a more evolved magma is
injected into the chamber occupied by a more primitive one. To
evaluate this hypothesis, a study has been conducted on the
silicate textures and major element geochemistry of the
silicate-rich
layers above and below the MG4 chromitite package in
the Critical Zone of the Rustenburg Layered Suite, part of the
Bushvel Complex in South Africa.The MG4 chromitite package consists
of several chromitite seamsseparated by silicate
layers.
Orthopyroxene and plagioclase (interstitial plagioclase) are
observed in large amounts throughout the silicate layer, with less
abundant clinopyroxene and some trace amounts of biotite.
Throughout the silicate-rich
layers above and below the MG4
chromitite
layers (MG4 pyroxenite), the orthopyroxene exhibits no
major compositional variation in major elements (Mg#= 1.15-1.25).
This is also observed in the clinopyroxene composition throughout
the study area. However, plagioclase, which dominates the lower
part of the stratigraphy, varies in composition with a decrease in
the calcium content (Ca= 0.8-0.5) and a simultaneous increase in
the sodium content (Na=0.2-0.5). These similarities between the
rocks above and below the MG4 chromitite
layers suggest that the
chromitite layer originated from a single magma or a mixture of two
magmas with similar composition. This model is supported by the
observed thin sections where orthopyroxene occurs as euhedral
grains throughout the section especially above the 63.13m depth
lying above the plagioclase –rich layer. Trace element analysis
further suggest that the magma that crystallized the
plagioclase-rich lower part mixed with the influx of new magma rich
in Mg to crystallize the rocks of the upper sequence dominated by
orthopyroxene, clinopyroxene and Na-rich plagioclase.
Advisors/Committee Members: Dr J Roberts (advisor).
Subjects/Keywords: Chromitite
layers; South
africa; Bushveld
complex;
UCTD
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Jolayemi, O. O. (2011). The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/29072
Chicago Manual of Style (16th Edition):
Jolayemi, Olutola O. “The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa.” 2011. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://hdl.handle.net/2263/29072.
MLA Handbook (7th Edition):
Jolayemi, Olutola O. “The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa.” 2011. Web. 16 Jan 2021.
Vancouver:
Jolayemi OO. The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa. [Internet] [Masters thesis]. University of Pretoria; 2011. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/2263/29072.
Council of Science Editors:
Jolayemi OO. The silicate
mineralogy of the MG4 chromitite package in the eastern part of the
Bushveld complex, South Africa. [Masters Thesis]. University of Pretoria; 2011. Available from: http://hdl.handle.net/2263/29072
University of Pretoria
22.
Ntlokwana, Andile.
The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers.
Degree: Materials Science and
Metallurgical Engineering, 2013, University of Pretoria
URL: http://hdl.handle.net/2263/37321
► The basic fuel unit of the High Temperature Reactor (HTR) of the Pebble Bed Modular Reactor (PBMR) is a uranium dioxide kernel coated with a…
(more)
▼ The basic fuel unit of the High Temperature Reactor
(HTR) of the Pebble Bed Modular Reactor (PBMR) is a uranium dioxide
kernel coated with a buffer layer, an inner pyrolytic carbon (IPyC)
layer, a silicon carbide (SiC) layer and an outer pyrolytic carbon
(OPyC) layer and is commonly referred to as a TRISO particle.
Thousands of these micro-spheres are embedded in a graphite matrix
and pressed to form a fuel sphere. During the manufacture of the
TRISO particles and the fuel spheres there is a production of TRISO
particles with cracked/broken
layers, especially the SiC layer.
Before the irradiation of the fresh fuel in the nuclear reactor it
is of the utmost importance to quantify the failed fractions in
fresh fuel as this information is very useful in the general
understanding of fuel behaviour, calculation of risk and safety
margins, and prediction of long term fuel behaviour. For this
reason the burn-leach method has been applied for the quality
control of the fresh fuel. In this work, several aspects of the
burn-leach method that affect the efficiency of the method were
studied. Aspects that were investigated are: qualitative aspects,
layer properties, quantitative aspects, variants of the burn-leach
method and lastly statistical information from the burn-leach
data.
The results obtained were as follows: Studies in this
dissertation suggest that partial leaching of uranium in TRISO
particles with a defective SiC layer was a phenomenon that exists.
Although UO2 kernel equivalents were successfully determined by
burn-leach method for particles with fully broken SiC
layers,
certain particles leached uranium amounts that did not correspond
to single UO2 kernel equivalents; Evidence of occurrences of ‘slow
leaching’ in an acidic medium were evident for certain particles.
There were remnants of uranium dioxide kernels that had been
partially leached after the full 16 hours. This behaviour led to
inconclusive results on the absolute number of defective particles
in a given population; Investigations suggest that there is at
least circumstantial evidence that the BL method combined with
X-ray tomography provides information about the integrity of the
SiC layer, and why one particle leaches and the other does not.
Neither the burn-leach nor the leach-burn-leach analysis is
sufficient to be used as a stand-alone method to quantify the
number of particles with defective SiC
layers in a given TRISO
particle population. The two tests need to be coupled to other
techniques such as high resolution tomography for an extensive
quantification of the layer defects; Burn-leach has to be designed
to test for the layer integrity on a microscopic level as opposed
to testing for the broken shells only, as was done by the normal
burn-leach based on the German program. The leach time was not
sufficient in its present form; Burn-leach results indicated that
oxidation times of 96 hours at 750 °C under atmospheric pressure
did not negatively affect the mechanical strength of the silicon
carbide layer of freshly-manufactured TRISO particles,…
Advisors/Committee Members: Groot, D.R. (advisor), De Villiers, J.P.R. (coadvisor).
Subjects/Keywords: Burn-leach; TRISO
particles;
Layers;
Uranium; UCTD
Record Details
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Ntlokwana, A. (2013). The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers. (Masters Thesis). University of Pretoria. Retrieved from http://hdl.handle.net/2263/37321
Chicago Manual of Style (16th Edition):
Ntlokwana, Andile. “The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers.” 2013. Masters Thesis, University of Pretoria. Accessed January 16, 2021.
http://hdl.handle.net/2263/37321.
MLA Handbook (7th Edition):
Ntlokwana, Andile. “The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers.” 2013. Web. 16 Jan 2021.
Vancouver:
Ntlokwana A. The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers. [Internet] [Masters thesis]. University of Pretoria; 2013. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/2263/37321.
Council of Science Editors:
Ntlokwana A. The
Efficiency of the burn-leach method in assessing the integrity of
TRISO coated particle layers. [Masters Thesis]. University of Pretoria; 2013. Available from: http://hdl.handle.net/2263/37321
Universidade Nova
23.
Krasilnikova, Daria.
Untitled: connecting layers of confusion, sensation and transformation.
Degree: 2012, Universidade Nova
URL: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/9663
► Dissertação para obtenção do Grau de Mestre em Arte e Ciência do Vidro
I believe that glass is a higher substance than most materials. It…
(more)
▼ Dissertação para obtenção do Grau de Mestre
em Arte e Ciência do Vidro
I believe that glass is a higher substance than most materials. It is a material reflecting humanity. For me, glass is at once a symbolic personification of human beings and at once a state of complete confusion. It is hard to work with. You either have to be talented or patient in order to pass through all the challenges to achieve the highest point of development and harmony. It is like working to be in balance with the material. At times I see it as my own reflection. Maybe I was chosen to be here. Glass making is at some point its own philosophical school, with its systems and meditation, with the training and frustration. It is its own world, its own orbital where we are spinning. Some are closer to the core and some are farther away, but working with glass demands that we all go through the layers to get to the core. It is not maybe as straight as we might hope and doesn’t quite fit the scientific rules. Glass seems to me to be a labyrinth with a goal of the 8th chakra, being a Master in glass making.
Two years ago I chose to move to Portugal and work with glass. Looking at all the wonderful glass hand-made objects around me gave me a sense of excitement. I could not believe that I would be able to do the same. The strong desire to achieve new techniques left me excited while at the same time confused and frustrated. That feeling carried with me through the whole time of the program. The state of confusion, insecurity in my skills, and possibilities were constantly changing. But it never disappeared.
I now propose to explain my personal transformation, layer by layer, as I also work to explain how a young lady from Russia meets glass art and glass science, and attempts to understand their interactions.
In this work colored glass was produced using the gold nanoparticles and the layer by layer deposition of polyelectrolytes through dip coating in order to apply it to artworks that use glass as a medium. Gold was used aiming to obtain a range of colors from purple to blue. The gold nanoparticles were applied to a glass by immersing samples with previously applied multilayers films with polyelectrolytes. A chosen temperature was used both for reduction and fixation of the nanoparticles into the glass. Attention was focused on the influence of used temperature during thermal treatment for color fixation. Furthermore, several experiments took place in order to clarify the efficiency of applying texture to the sample with the purpose of color fixation. The effect of variables such as the number of polyelectrolytes multilayers and metal solution concentration on the resulting color was also studied. As a potential reducing agent of metals such as gold, the tin element can have influenced on the nanoparticles formation process. An experiment was performed in two samples of soda-lime glass on the surface of which tin was implanted. The influence of tin implantation on the final color of the sample was determined. The samples were characterized…
Advisors/Committee Members: Wiley III, Robert, Ventura, Márcia.
Subjects/Keywords: Glass; Layers; Art; Labyrinth; Sensation; Transformation
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APA (6th Edition):
Krasilnikova, D. (2012). Untitled: connecting layers of confusion, sensation and transformation. (Thesis). Universidade Nova. Retrieved from http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/9663
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):
Krasilnikova, Daria. “Untitled: connecting layers of confusion, sensation and transformation.” 2012. Thesis, Universidade Nova. Accessed January 16, 2021.
http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/9663.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Krasilnikova, Daria. “Untitled: connecting layers of confusion, sensation and transformation.” 2012. Web. 16 Jan 2021.
Vancouver:
Krasilnikova D. Untitled: connecting layers of confusion, sensation and transformation. [Internet] [Thesis]. Universidade Nova; 2012. [cited 2021 Jan 16].
Available from: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/9663.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Krasilnikova D. Untitled: connecting layers of confusion, sensation and transformation. [Thesis]. Universidade Nova; 2012. Available from: http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/9663
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Vermont
24.
Alghamdi, Saleh Jaman.
A Preliminary Study On The Interfacial Strength Of Red Abalone.
Degree: MS, Civil and Environmental Engineering, 2016, University of Vermont
URL: https://scholarworks.uvm.edu/graddis/633
► Nacre is a hierarchical material found within the tough shells of red abalone. Despite being composed of calcium carbonate, nacre exhibits remarkable mechanical properties…
(more)
▼ Nacre is a hierarchical material found within the tough shells of red abalone. Despite being composed of calcium carbonate, nacre exhibits remarkable mechanical properties resulting from the nanoscale brick-and-mortar structure made from aragonite polygons. The objective of this research is to elucidate the toughening mechanisms associated with the interfacial resistance of red abalone. This was achieved by studying the mechanical behavior of dry nacre under pure shear and tension, and characterizing the associated fracture mechanisms using optical and scanning electron microscopes. Mathematical modeling was applied to further quantify the contribution of protein chains, nano-asperities and shear pillars to interfacial strengths. Preliminary conceptual models were proposed to elucidate the toughening mechanisms of polymorphic aragonite structures in red abalone. The findings can extend our understanding of the mechanical behavior of natural materials and promote the research and development of high performance bioinspired materials.
Advisors/Committee Members: Ting Tan.
Subjects/Keywords: Growth Layers; Nacre; Civil Engineering; Engineering
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APA (6th Edition):
Alghamdi, S. J. (2016). A Preliminary Study On The Interfacial Strength Of Red Abalone. (Thesis). University of Vermont. Retrieved from https://scholarworks.uvm.edu/graddis/633
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):
Alghamdi, Saleh Jaman. “A Preliminary Study On The Interfacial Strength Of Red Abalone.” 2016. Thesis, University of Vermont. Accessed January 16, 2021.
https://scholarworks.uvm.edu/graddis/633.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Alghamdi, Saleh Jaman. “A Preliminary Study On The Interfacial Strength Of Red Abalone.” 2016. Web. 16 Jan 2021.
Vancouver:
Alghamdi SJ. A Preliminary Study On The Interfacial Strength Of Red Abalone. [Internet] [Thesis]. University of Vermont; 2016. [cited 2021 Jan 16].
Available from: https://scholarworks.uvm.edu/graddis/633.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Alghamdi SJ. A Preliminary Study On The Interfacial Strength Of Red Abalone. [Thesis]. University of Vermont; 2016. Available from: https://scholarworks.uvm.edu/graddis/633
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Colorado
25.
Agarwal, Kirun.
Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool.
Degree: MS, Computer Science, 2013, University of Colorado
URL: https://scholar.colorado.edu/csci_gradetds/57
► The Internet can be useful in supporting teacher planning and instruction. However, there is no way for teachers to know if they are progressing…
(more)
▼ The Internet can be useful in supporting teacher planning and instruction. However, there is no way for teachers to know if they are progressing through the curriculum at an appropriate pace. The focus of this thesis is exploring the use of visualizations in aiding teacher planning and instruction. Visualizations were created using Processing, an open source programming language and environment. Data from the Curriculum Customization Service was used to display curricular flow. The visualization contains three
layers representing the group's flow, the ideal flow, and an individual user's flow. These
layers show the flow through the units of the curriculum. Another graph can be displayed by hovering over lines in the layered graph, which shows the most popular concepts among users. The visualizations were tested by asking five users to complete three tasks using the visualizations. All five users were able to complete the tasks though some had more difficulty than others, showing that while many improvements are needed, the visualizations do allow users to see their curricular flow and make comparisons.
Advisors/Committee Members: Tamara Sumner, Jonathan Ostwald, Katie Ostwald.
Subjects/Keywords: curriculum; flow; layers; Processing; visualization; Computer Sciences
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APA (6th Edition):
Agarwal, K. (2013). Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool. (Masters Thesis). University of Colorado. Retrieved from https://scholar.colorado.edu/csci_gradetds/57
Chicago Manual of Style (16th Edition):
Agarwal, Kirun. “Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool.” 2013. Masters Thesis, University of Colorado. Accessed January 16, 2021.
https://scholar.colorado.edu/csci_gradetds/57.
MLA Handbook (7th Edition):
Agarwal, Kirun. “Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool.” 2013. Web. 16 Jan 2021.
Vancouver:
Agarwal K. Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool. [Internet] [Masters thesis]. University of Colorado; 2013. [cited 2021 Jan 16].
Available from: https://scholar.colorado.edu/csci_gradetds/57.
Council of Science Editors:
Agarwal K. Visualizing The Flow And Usage Of Curricular Components In An Online Curriculum Planning And Teaching Tool. [Masters Thesis]. University of Colorado; 2013. Available from: https://scholar.colorado.edu/csci_gradetds/57
Univerzitet u Beogradu
26.
Pjević, Dejan J., 1980-.
Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену.
Degree: Fizički fakultet, 2019, Univerzitet u Beogradu
URL: https://fedorabg.bg.ac.rs/fedora/get/o:19310/bdef:Content/get
► Физика - Физика танких слојева / Physics - Thin films
The subject of this PhD thesis is formation and characterization of TiO2 thin layers deposited…
(more)
▼ Физика - Физика танких слојева / Physics - Thin
films
The subject of this PhD thesis is formation and
characterization of TiO2 thin layers deposited by three different
physical vapor deposition (PVD) methods. The aim was to define
conditions for producing thin layers with optical characteristics
that are desirable for photocatalytic purposes. Beside monitoring
the impact of deposition parameters during synthesis of TiO2 thin
layers, to achieve the aim effects of different annealing
conditions were investigated, roles of the oxygen and titanium
vacancy places in the crystal lattice and effects of nitrogen
doping and role of the nitrogen incorporation sites in crystal
lattice on optical and photocatalytic properties were studied. Some
of the characterization techniques employed in this research were
transmission electron microscopy, Rutherford backscattering
spectrometry, X-ray diffraction and spectroscopy techniques: X-ray
photoemission and UV/Vis. Experimental results in the thesis are
divided into three sections which are referred to PVD method used
for deposition of thin films: e-beam assisted evaporation, RF
magnetron sputtering and reactive ion
sputtering...
Advisors/Committee Members: Petrović, Suzana.
Subjects/Keywords: TiO2; thin layers; deposition; nitrogen doping;
photocatalysis
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APA (6th Edition):
Pjević, Dejan J., 1. (2019). Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену. (Thesis). Univerzitet u Beogradu. Retrieved from https://fedorabg.bg.ac.rs/fedora/get/o:19310/bdef:Content/get
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):
Pjević, Dejan J., 1980-. “Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену.” 2019. Thesis, Univerzitet u Beogradu. Accessed January 16, 2021.
https://fedorabg.bg.ac.rs/fedora/get/o:19310/bdef:Content/get.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Pjević, Dejan J., 1980-. “Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену.” 2019. Web. 16 Jan 2021.
Vancouver:
Pjević, Dejan J. 1. Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену. [Internet] [Thesis]. Univerzitet u Beogradu; 2019. [cited 2021 Jan 16].
Available from: https://fedorabg.bg.ac.rs/fedora/get/o:19310/bdef:Content/get.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Pjević, Dejan J. 1. Проучавање и модификација танких слојева ТiО2 добијених
физичким методама депоновања за фотокаталитичку примену. [Thesis]. Univerzitet u Beogradu; 2019. Available from: https://fedorabg.bg.ac.rs/fedora/get/o:19310/bdef:Content/get
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Notre Dame
27.
Alan H. Duong.
Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>.
Degree: Aerospace and Mechanical Engineering, 2019, University of Notre Dame
URL: https://curate.nd.edu/show/q237hq41667
► Viscous drag reduction in turbulent boundary layers has been an exceptionally interesting topic within fluid dynamics for several decades. The field itself is rich…
(more)
▼ Viscous drag reduction in turbulent boundary
layers has been an exceptionally interesting topic within fluid
dynamics for several decades. The field itself is rich with
studies, efforts, failures and successes starting back from the
1950s. That being said, with each attempt, experiment, simulation
and trial, the field grows little by little and what is commonly
understood today is a result of all the work that has came before.
The work presented in this dissertation contributes to the field
from two different aspects; the practical application of improving
the performance of aerodynamic vehicles and the understanding of
complex interactions and dynamic mechanisms that exist withing
wall-bounded turbulent flows. A series of experimental drag
reduction studies with the utilization of a novel pulsed-DC plasma
actuator as the primary means of flow control were conducted.
Viscous drag reduction over a flat plate in a zero-pressure
gradient boundary layer was achieved over a decade of Mach numbers
all while maintaining net power savings. Accompanying flow
diagnostics revealed a stabilization and reduction of the spanwise
mean flow distortion of the wall-layer as evidenced by a decrease
in the activity of the wall streak structure, which plays a
significant role in turbulence production and, subsequently,
viscous drag.
Advisors/Committee Members: Eric Matlis, Committee Member, Thomas C. Corke, Research Director, Alan Cain, Committee Member, Flint Thomas, Committee Member.
Subjects/Keywords: Turbulent Boundary Layers; Mechanical Engineering; Aerospace Engineering
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APA (6th Edition):
Duong, A. H. (2019). Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>. (Thesis). University of Notre Dame. Retrieved from https://curate.nd.edu/show/q237hq41667
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):
Duong, Alan H.. “Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>.” 2019. Thesis, University of Notre Dame. Accessed January 16, 2021.
https://curate.nd.edu/show/q237hq41667.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Duong, Alan H.. “Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>.” 2019. Web. 16 Jan 2021.
Vancouver:
Duong AH. Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>. [Internet] [Thesis]. University of Notre Dame; 2019. [cited 2021 Jan 16].
Available from: https://curate.nd.edu/show/q237hq41667.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Duong AH. Active Turbulent Boundary Layer Control: An Experimental
Evaluation of Viscous Drag Reduction Using Pulsed-DC Plasma
Actuators</h1>. [Thesis]. University of Notre Dame; 2019. Available from: https://curate.nd.edu/show/q237hq41667
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Waterloo
28.
Atoufi, Amir.
Turbulence in stably stratified boundary layers.
Degree: 2020, University of Waterloo
URL: http://hdl.handle.net/10012/16515
► In this thesis, turbulence dynamics for a stably stratified boundary layer is studied. The processes by which stable boundary layers are formed through strong surface…
(more)
▼ In this thesis, turbulence dynamics for a stably stratified boundary layer is studied. The processes by which stable boundary layers are formed through strong surface cooling imposed on neutrally stratified wall-bounded turbulence is explored first using high-resolution direct numerical simulation at a moderate Reynolds number. The adjustment of the flow to the imposed strong surface cooling is investigated.
Secondly, characteristics of near-wall turbulence at quasi-stationarity under strong wall cooling are studied. It is shown that if turbulence reaches quasi-stationarity, the characteristics of quasi-stationary near-wall turbulence, even with the strongest wall cooling rate, are generally similar to the weakly stratified case. The effects of strong stable stratification on the characteristics of near-wall turbulence are transient.
It is shown that among mechanisms that contribute to the budget of turbulent kinetic energy, transfer and pressure-work are more dependent on the stratification if turbulence reaches quasi-stationarity. Buoyancy destruction has a considerable effect on the evolution of turbulence producing eddies but not on production itself at stationarity. Relevant length scales are also discussed in detail.
In summary, it is found that the behaviour of near-wall turbulence at quasi-stationarity is approximately similar to weakly stratified cases, regardless of the choice of upper boundary condition.
Finally, the kinetic energy cascade in a stably stratified boundary layer is investigated. A mathematical framework to incorporate vertical scales into the conventional kinetic energy spectrum and its budget is introduced.
It is shown that energetic streamwise scales (λx) become larger with increasing vertical scale. For the strongest stratification, for which the turbulence becomes intermittent, the energetic streamwise scales are suppressed, and energy density resides in λx of the size of the domain. It is shown that in the unstratified case, vertical scales of the size comparable to the height of the logarithmic layer connect viscous regions to the outer layer. By contrast, in stratified cases, such a connection is not observed.
Subjects/Keywords: Turbulence; Wall-bounded flows; Stratified Boundary Layers
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APA (6th Edition):
Atoufi, A. (2020). Turbulence in stably stratified boundary layers. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/16515
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):
Atoufi, Amir. “Turbulence in stably stratified boundary layers.” 2020. Thesis, University of Waterloo. Accessed January 16, 2021.
http://hdl.handle.net/10012/16515.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Atoufi, Amir. “Turbulence in stably stratified boundary layers.” 2020. Web. 16 Jan 2021.
Vancouver:
Atoufi A. Turbulence in stably stratified boundary layers. [Internet] [Thesis]. University of Waterloo; 2020. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/10012/16515.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Atoufi A. Turbulence in stably stratified boundary layers. [Thesis]. University of Waterloo; 2020. Available from: http://hdl.handle.net/10012/16515
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Minnesota
29.
Hildebrand, Nathaniel.
Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions.
Degree: PhD, Aerospace Engineering and Mechanics, 2019, University of Minnesota
URL: http://hdl.handle.net/11299/203577
► This dissertation is about the modal and nonmodal stability of an oblique shock wave impinging on a Mach 5.92 laminar boundary layer at a transitional…
(more)
▼ This dissertation is about the modal and nonmodal stability of an oblique shock wave impinging on a Mach 5.92 laminar boundary layer at a transitional Reynolds number. The adverse pressure gradient of the oblique shock wave causes the laminar boundary layer to separate from the wall, resulting in the formation of a recirculation bubble. For sufficiently large oblique shock angles, the recirculation bubble is unstable to three-dimensional perturbations, and the flow bifurcates from its original laminar state. We use direct numerical simulation (DNS) and global stability analysis (GSA) to show that this first occurs at a critical oblique shock angle of 12.9 degrees. The least-stable global mode is stationary at bifurcation, and it takes place at a nondimensional spanwise wavenumber of 0.25, in good agreement with the DNS results. Examination of the critical global mode reveals that it originates from an interaction between small spanwise corrugations at the incident shock base, streamwise vortices inside the recirculation bubble, and spanwise modulation of the bubble strength. Furthermore, the global mode drives the formation of long streamwise streaks downstream of the bubble. This stationary three-dimensional instability is similar to other mechanisms observed in laminar recirculation bubbles. We show that centrifugal instability plays no role in the self-sustaining mechanism of the stationary global mode. Further, we employ an adjoint solver to corroborate our physical interpretations by showing that the critical global mode is most sensitive to base flow modifications that are entirely contained inside the recirculation bubble. We also perform a parametric study to determine the effect of freestream Mach number on shock-wave/boundary-layer interaction (SWBLI) instability. Along with DNS and GSA, we investigate the physical mechanisms responsible for transient growth in an SWBLI using a power iteration method. This approach lets perturbations propagate upstream and downstream, which allows us to capture the complex physics associated with the recirculation bubble and understand how it amplifies fluctuations. For a Mach 5.92 boundary layer with no oblique shock wave, we demonstrate that the transient response arises from the inviscid Orr mechanism, the Landahl lift-up effect, and first-mode instability. The optimal transient growth for this spatially-developing boundary layer with a nondimensional streamwise domain length of 235 is G=1.69x103 and occurs at a spanwise wavenumber of 0.6. This corresponds to an amplification of 4.11x101, which is similar to that seen in a variety of parallel boundary layer flows. We compute the optimal transient growth of an SWBLI at the exact same conditions as the spatially-developing boundary layer. The presence of an oblique shock wave changes the optimal transient response such that G=1.36x107 at a spanwise wavenumber of 0.6. Hence, the transient growth in an SWBLI is four orders of magnitude larger than the transient growth in a spatially-developing boundary layer. The…
Subjects/Keywords: Bifurcations; Boundary layers; Flow instability; Shock waves
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APA ·
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MLA ·
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Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Hildebrand, N. (2019). Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/203577
Chicago Manual of Style (16th Edition):
Hildebrand, Nathaniel. “Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions.” 2019. Doctoral Dissertation, University of Minnesota. Accessed January 16, 2021.
http://hdl.handle.net/11299/203577.
MLA Handbook (7th Edition):
Hildebrand, Nathaniel. “Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions.” 2019. Web. 16 Jan 2021.
Vancouver:
Hildebrand N. Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions. [Internet] [Doctoral dissertation]. University of Minnesota; 2019. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11299/203577.
Council of Science Editors:
Hildebrand N. Modal and nonmodal stability analysis of shock-wave/boundary-layer interactions. [Doctoral Dissertation]. University of Minnesota; 2019. Available from: http://hdl.handle.net/11299/203577
University of Melbourne
30.
Ain, Hurmat Ul.
Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity.
Degree: 2018, University of Melbourne
URL: http://hdl.handle.net/11343/212716
► Turbulent flows are of ubiquitous technological importance due to their wide variety of applications. The action of vortical motions plays a vital role in turbulence…
(more)
▼ Turbulent flows are of ubiquitous technological importance due to their wide variety of applications. The action of vortical motions plays a vital role in turbulence production, dissipation, and time-averaged turbulence statistics. Therefore, it is essential to understand the flow features responsible for the inertial mechanisms of turbulence and ultimately the mean distribution of momentum. The flow field associated with a vortex ring advecting towards a stationary/moving wall is investigated using planar PIV. This study aims to clarify the mechanisms of turbulent inertia associated with the interaction of advecting regions of concentrated vorticity and distributed vorticity. These physical simulations represent aspects of the instantaneous flow field interactions known to exist in turbulent wall-bounded flows. To allow for an explicit study of these interactions and avoid background turbulence, unsteady, laminar, vortex ring experiments are conducted under reproducible initial conditions. The experiments are conducted in a large water tank. The bottom wall of the tank is fitted with a conveyor belt driven by a servo motor to generate a time evolving shear layer. Laminar vortex rings are produced using a piston cylinder apparatus that is driven by a stepper motor and controlled using a computer.
For opposite sign vorticity interactions between the vortex ring and shear layer vorticity, the passage of the vortex ring above the wall results in a lifting of the near wall fluid. This gives rise to the formation of a primary hairpin vortex with the same sign vorticity as the top core of the vortex ring. Results indicate that the generation of new coherent vortex motion introduce geometric and kinematic asymmetries that generates a contribution to turbulent inertia. This action creates local imbalances in the stress field leading to momentum inhomogeneities. To gain an in-depth knowledge of the parameters governing the formation of a primary hairpin vortex, a parametric study is conducted using four factors: the initial wall-normal location of the vortex ring, the circulation ratio between the vortex ring and shear layer, the displacement thickness, and the incidence angle of the vortex ring. This led to a precise and detailed characterisation of the primary hairpin. The development of a unique framework based upon the mean momentum equation to analyse momentum transport and exchange between the ring and the shear-layer is discussed in detail. New observations on the vortex ring/moving wall simulations are presented. In general, the time rate of change of momentum trends for the vortex ring and hairpin indicates a flux of momentum from the ring to hairpin vortex during the initial stages of interaction. Some of the momentum from the vortex ring is transported to the hairpin that is contributing towards wall-layer vorticity roll-up. There is compelling evidence that vortex rings are stable, coherent and long-lived features of the flow, and capable of transporting momentum to near-wall vorticity field without coming too…
Subjects/Keywords: vortex ring; vorticity; boundary layers; momentum transport
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
Ain, H. U. (2018). Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/212716
Chicago Manual of Style (16th Edition):
Ain, Hurmat Ul. “Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity.” 2018. Doctoral Dissertation, University of Melbourne. Accessed January 16, 2021.
http://hdl.handle.net/11343/212716.
MLA Handbook (7th Edition):
Ain, Hurmat Ul. “Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity.” 2018. Web. 16 Jan 2021.
Vancouver:
Ain HU. Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity. [Internet] [Doctoral dissertation]. University of Melbourne; 2018. [cited 2021 Jan 16].
Available from: http://hdl.handle.net/11343/212716.
Council of Science Editors:
Ain HU. Mechanisms of momentum transport associated with the interaction of concentrated and distributed regions of vorticity. [Doctoral Dissertation]. University of Melbourne; 2018. Available from: http://hdl.handle.net/11343/212716
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