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1.
Lovely, M R.
Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity.
Degree: Astrophysics, 2010, University of Calicut
URL: http://shodhganga.inflibnet.ac.in/handle/10603/3912 
► The sun which is an important part of solar system plays a significant role in influencing the life on Earth, disrupting electrical power grids, satellite…
(more)
▼ The sun which is an important part of solar system
plays a significant role in influencing the life on Earth,
disrupting electrical power grids, satellite and telecommunication
facilities, air-traffic etc. This is due to various solar cycle and
activity phenomena like sunspots, flares and CMEs taking place in
the sun that also have effect on the earth’s environment and
climate. So it is important to study sunspots and associated
phenomena. Before the advent of space era, from surface
observations, it was difficult to infer the solar internal
structure and dynamics. With the help of SOHO/MDI (Michelson
Doppler Imager), it is now possible to infer internal structure by
computing the velocity of sound waves passing through the sun, that
provide clues to unravel the secrets of sun’s eleven year cycle and
associated phenomena. On the other hand MDI instruments aboard SOHO
measure the line of sight component of magnetic field structure of
the sun. SOT instrument on Hinode yields very high resolution
longitudinal and vector magnetic field components at the
photospheric levels. With the valuable data from ground based
observatories and from the space observatories, from dynamics and
magnetic field structure of the sunspot on the surface, now we are
at a better position to understand internal structure of the
convective envelope where sunspots are supposed to be originated.
Hence, it is important to study sunspots’ dynamics and magnetic
field structure on the surface as they are supposed to be tracers
of internal dynamics and magnetic field structure of solar
convective envelope. This research study consists of studying of
dynamics and magnetic field structure of the solar convective
envelope by using dynamics and magnetic field structure on the
solar surface. The thesis has been organized as follows. The first
chapter consists of introduction to solar activities like sunspot,
flares and magnetic field structures associated with the sunspots.
The second chapter deals with abnormal rotation rates associated
with bipolar sunspots that have leader and follower. Using six
years (1969-1974) of data of sunspot groups from the white light
pictures of the Kodaikanal Observatory, rotation rates of the
leading and the following sunspots and the rate of change of
longitudinal separation during their life times are
computed.
Conclusions p. 137-142, Bibliography p.
143-153
Advisors/Committee Members: Hiremath, K M.
Subjects/Keywords: Astrophysics; Magnetic field; Toroidal magnetic field structure
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APA (6th Edition):
Lovely, M. R. (2010). Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity. (Thesis). University of Calicut. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/3912
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):
Lovely, M R. “Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity.” 2010. Thesis, University of Calicut. Accessed April 12, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/3912.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lovely, M R. “Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity.” 2010. Web. 12 Apr 2021.
Vancouver:
Lovely MR. Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity. [Internet] [Thesis]. University of Calicut; 2010. [cited 2021 Apr 12].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/3912.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lovely MR. Study of dynamics and magnetic field structure of the
solar convective envelope using sunspot activity. [Thesis]. University of Calicut; 2010. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/3912
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
King Abdullah University of Science and Technology
2.
Contreras, Maria F.
Magnetic Nanowires as Materials for Cancer Cell Destruction.
Degree: Biological and Environmental Sciences and Engineering (BESE) Division, 2015, King Abdullah University of Science and Technology
URL: http://hdl.handle.net/10754/583378
► Current cancer therapies are highly cytotoxic and their delivery to exclusively the affected site is poorly controlled, resulting in unavoidable and often severe side effects.…
(more)
▼ Current cancer therapies are highly cytotoxic and their delivery to exclusively the affected site
is poorly controlled, resulting in unavoidable and often severe side effects. In an effort to overcome
such issues,
magnetic nanoparticles have been recently gaining relevance in the areas of biomedical
applications and therapeutics, opening pathways to alternative methods. This led to the concept of
magnetic particle hyperthermia in which
magnetic nano beads are heated by a high power
magnetic
field. The increase in temperature kills the cancer cells, which are more susceptible to heat in
comparison to healthy cells.
In this dissertation, the possibility to kill cancer cells with
magnetic nanowires is evaluated.
The idea is to exploit a magnetomechanical effect, where nanowires cause cancer cell death through
vibrating in a low power
magnetic field. Specifically, the
magnetic nanowires effects to cells in culture
and their ability to induce cancer cell death, when combined with an alternating
magnetic field, was
investigated.
Nickel and iron nanowires of 35 nm diameter and 1 to 5 μm long were synthesized by electrodeposition
into nanoporous alumina templates, which were prepared using a two-step anodization
process on highly pure aluminum substrates. For the cytotoxicity studies, the nanowires were added
to cancer cells in culture, varying the incubation time and the concentration. The cell-nanowire
interaction was thoroughly studied at the cellular level (mitochondrial metabolic activity, cell membrane
integrity and, apoptosis/necrosis assay), and optical level (transmission electron and confocal
microscopy). Furthermore, to investigate their therapeutic potential, an alternating
magnetic field
was applied varying its intensity and frequency. After the
magnetic field application, cells health
was measured at the mitochondrial activity level.
Cytotoxicity results shed light onto the cellular tolerance to the nanowires, which helped in
establishing the appropriate nanowire concentrations to use the nanowires + alternating
magnetic
field combination as a cancer treatment. Different levels of cancer cell death were achieved by
changing the incubation time of the nanowires with the cells and the alternating
magnetic field
parameters. Cell viability was significantly affected in terms of mitochondrial activity and cell
membrane integrity after applying the treatment (nanowires + alternating
magnetic field) using a
low-frequency alternating
magnetic.
Theoretical calculations considering the
magnetic and viscous torques showed that the nanowires
vibrate as a consequence of the applied
magnetic field. This, alongside the fact that no temperature
increase was measured during the treatment, makes the magnetomechanical effect the most probable
action mechanism in the applied treatment that is inducing cell death.
Inducing cancer cell death via magnetomechanical action using
magnetic nanowires resulted in
killing up to 60% of cancer cells with only 10 minutes of treatment. The required
magnetic…
Advisors/Committee Members: Ravasi, Timothy (advisor), Kosel, Jürgen (committee member), Pain, Arnab (committee member), Merzaban, Jasmeen (committee member), Wells, Christine A. (committee member).
Subjects/Keywords: Magnetic nanowires; Mechanotransduction; Low-power magnetic field
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APA (6th Edition):
Contreras, M. F. (2015). Magnetic Nanowires as Materials for Cancer Cell Destruction. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/583378
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):
Contreras, Maria F. “Magnetic Nanowires as Materials for Cancer Cell Destruction.” 2015. Thesis, King Abdullah University of Science and Technology. Accessed April 12, 2021.
http://hdl.handle.net/10754/583378.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Contreras, Maria F. “Magnetic Nanowires as Materials for Cancer Cell Destruction.” 2015. Web. 12 Apr 2021.
Vancouver:
Contreras MF. Magnetic Nanowires as Materials for Cancer Cell Destruction. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2015. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/10754/583378.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Contreras MF. Magnetic Nanowires as Materials for Cancer Cell Destruction. [Thesis]. King Abdullah University of Science and Technology; 2015. Available from: http://hdl.handle.net/10754/583378
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Alberta
3.
Khaleque, Tasnuva.
Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field.
Degree: MS, Department of Mechanical Engineering, 2009, University of Alberta
URL: https://era.library.ualberta.ca/files/ng451j11q
► Hydrogel smart polymers have achieved a great attention in the research area of drug delivery, MEMS/NEMS, microfluidics and sensor design because of their responsiveness to…
(more)
▼ Hydrogel smart polymers have achieved a great
attention in the research area of drug delivery, MEMS/NEMS,
microfluidics and sensor design because of their responsiveness to
various environmental stimuli- pH, temperature, light, electric
field, enzyme etc. This thesis presents the modeling, fabrication
and study of the bending deformation of magnetic field sensitive
hydrogel micro fibers called ferrogels. The objective is to
externally actuate the ferrogel fibers by applying magnetic field,
for the application of targeted drug delivery inside the alveoli of
a human lung. Prediction of the bending deformation of the ferrogel
fibers is done by the Multiphysics Finite Element Modeling in an
Arbitrary Lagrangian Eulerian (ALE) framework. Ferrogel micro
fibers are fabricated and the bending deforma-tion is studied
experimentally by varying the aspect ratio of the fibers, volume
fraction of the magnetic particle content of the fibers and the
magnetic field strength. The numerical and experimental results are
compared. This is the first attempt to numerically predict the
bending deformation of ferrogel micro-fibers.
Subjects/Keywords: micro-ferrogel; magnetic-field; fabrication
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Manager
APA (6th Edition):
Khaleque, T. (2009). Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field. (Masters Thesis). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/ng451j11q
Chicago Manual of Style (16th Edition):
Khaleque, Tasnuva. “Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field.” 2009. Masters Thesis, University of Alberta. Accessed April 12, 2021.
https://era.library.ualberta.ca/files/ng451j11q.
MLA Handbook (7th Edition):
Khaleque, Tasnuva. “Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field.” 2009. Web. 12 Apr 2021.
Vancouver:
Khaleque T. Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field. [Internet] [Masters thesis]. University of Alberta; 2009. [cited 2021 Apr 12].
Available from: https://era.library.ualberta.ca/files/ng451j11q.
Council of Science Editors:
Khaleque T. Fabrication, modeling and experimental study of bending
deformation of micro-ferrogel fibers in a non-uniform magnetic
field. [Masters Thesis]. University of Alberta; 2009. Available from: https://era.library.ualberta.ca/files/ng451j11q
Addis Ababa University
4.
Bililign, Tsige.
SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
.
Degree: 2012, Addis Ababa University
URL: http://etd.aau.edu.et/dspace/handle/123456789/1227
► Neutron stars are the collapsed cores of some massive stars. These compact objects (NS) have incredibly high densities and the strong magnetic fields (Pulsars have…
(more)
▼ Neutron stars are the collapsed cores of some massive stars. These compact objects
(NS) have incredibly high densities and the strong
magnetic fields (Pulsars have
magnetic field 1012G,Magnetars have
magnetic field 1015G)[1]. Phenomena like
this trigger people to look for the solutions of Dirac equation in strong
magnetic
fields. In this thesis we discuss the properties of the solutions of the Dirac equation
in presence of a uniform background
magnetic field. The nature of the solutions, their
ortho-normality properties, dependence of these solutions on the choice of the vector
potential giving rise to the
magnetic field and explicit calculation the spin-sum of the
solutions are areas of emphasis.
Advisors/Committee Members: Dr. Legesse wetro.k (advisor).
Subjects/Keywords: SPIN-SUM;
STRONG MAGNETIC FIELD
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APA (6th Edition):
Bililign, T. (2012). SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
. (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/1227
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):
Bililign, Tsige. “SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
.” 2012. Thesis, Addis Ababa University. Accessed April 12, 2021.
http://etd.aau.edu.et/dspace/handle/123456789/1227.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bililign, Tsige. “SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
.” 2012. Web. 12 Apr 2021.
Vancouver:
Bililign T. SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
. [Internet] [Thesis]. Addis Ababa University; 2012. [cited 2021 Apr 12].
Available from: http://etd.aau.edu.et/dspace/handle/123456789/1227.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bililign T. SPIN-SUM TO DIRAC SOLUTIONS IN A VERY STRONG MAGNETIC FIELD
. [Thesis]. Addis Ababa University; 2012. Available from: http://etd.aau.edu.et/dspace/handle/123456789/1227
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Université de Neuchâtel
5.
Scalari, Giacomo.
Magneto-spectroscopy and development of terahertz quantum
cascade lasers.
Degree: 2005, Université de Neuchâtel
URL: http://doc.rero.ch/record/6021
► In this work we concentrate our efforts on the generation of laser emission at low THz frequencies (3-1 THz range) employing the quantum cascade technology.…
(more)
▼ In this work we concentrate our efforts on the
generation of laser emission at low THz frequencies (3-1 THz range)
employing the quantum cascade technology. Quantum cascade (QC)
lasers are unipolar semiconductor lasers based on intersubband
transitions in quantum wells that cover a large portion of the Mid
and Far Infrared electromagnetic spectrum. Two main research lines
have been followed: (i) the development of quantum cascade lasers
based on population inversion between parabolic subbands and (ii)
the development of low frequency QC lasers based on a
three-dimensional electron confinement induced by an external
magnetic field. (i) : Gain and laser action have been demonstrated
in different systems at frequencies of 3.4 3.6 THz exploiting
bound-to-bound and bound-to-continuum optical transition. A QC
laser emitting at 3.6 THz and based on a vertical transition and
resonant tunneling in a single quantum well has been demonstrated.
To overcome the limitations in performance of such a system, an
heterostructure laser based on a bound-to-continuum transition has
been developed. The structure was the first one to operate above
the technologically important temperature of liquid nitrogen. With
a further development of the bound-to-continuum design that
includes lower state lifetime reduction by optical phonon emission,
laser action was successfully achieved at 115 K. A study of
different waveguide mechanisms suitable for different THz
frequencies has also been carried out. (ii) : THz quantum cascade
lasers based on the in-plane confinement introduced by a strong
magnetic field applied perpendiculary to the plane of the layers
have been developed. A model system based on large single quantum
wells (50-60 nm wide) has been exploited to study this gain
mechanism. Such an approach led to the extension of the frequency
range of operation of QC lasers, with the demonstration of laser
action at 1.39 THz (220 m) which is the lowest frequency observed
to-date for this kind of technology. The size confinement induced
by the
magnetic field radically modifies the physics of the system
allowing laser action with extremely reduced threshold current
densities (0.65 A/cm2), a factor of 70 lower than any other quantum
cascade laser and among the lowest ever observed for a
semiconductor laser in general. Electron wavefunction localization
is at the basis of the observed effects. Resonances in transport
and in laser emission characteristics have been observed and
attributed to many-body phenomena. The
magnetic field has been used
also as a spectroscopic tool to investigate the structures
developed in the research line (i). Multi-frequency operation
obtained by selectively injecting carriers in the excited states of
a single quantum well structure has also been
demonstrated.
Advisors/Committee Members: Jérôme (Dir.).
Subjects/Keywords: magnetic field
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Manager
APA (6th Edition):
Scalari, G. (2005). Magneto-spectroscopy and development of terahertz quantum
cascade lasers. (Thesis). Université de Neuchâtel. Retrieved from http://doc.rero.ch/record/6021
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):
Scalari, Giacomo. “Magneto-spectroscopy and development of terahertz quantum
cascade lasers.” 2005. Thesis, Université de Neuchâtel. Accessed April 12, 2021.
http://doc.rero.ch/record/6021.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Scalari, Giacomo. “Magneto-spectroscopy and development of terahertz quantum
cascade lasers.” 2005. Web. 12 Apr 2021.
Vancouver:
Scalari G. Magneto-spectroscopy and development of terahertz quantum
cascade lasers. [Internet] [Thesis]. Université de Neuchâtel; 2005. [cited 2021 Apr 12].
Available from: http://doc.rero.ch/record/6021.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Scalari G. Magneto-spectroscopy and development of terahertz quantum
cascade lasers. [Thesis]. Université de Neuchâtel; 2005. Available from: http://doc.rero.ch/record/6021
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Washington
6.
Osofsky, Rachel Elizabeth.
Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment.
Degree: PhD, 2020, University of Washington
URL: http://hdl.handle.net/1773/45255
► The muon g-2 experiment at Fermilab aims to measure the anomalous magnetic moment of the muon, aμ, to a precision of 140 parts per billion…
(more)
▼ The muon g-2 experiment at Fermilab aims to measure the anomalous
magnetic moment of the muon, a
μ, to a precision of 140 parts per billion (ppb). The measurement will shed light on the current >3σ deviation between Standard Model calculations and the previous measurement made at Brookhaven National Laboratory, either resolving the discrepancy or confirming it to >5σ. In the muon g-2 experiment, muons are stored in a
magnetic storage ring and their decays are observed. In order to reach the precision goal, the
magnetic field experienced by the muons must be known with an uncertainty of \SI{70}{ppb} or less. To this end, the
magnetic field was shimmed to unprecedented homogeneity. Two measurement systems are used to track the evolution of the
magnetic field. This dissertation describes the motivations for the g-2 experiment, gives a brief overview of the experimental principles, introduces the
magnetic field measurement hardware, describes the
magnetic field shimming process, and presents an analysis of the
magnetic field tracking for data collected in spring 2018 during run 1 of the Fermilab muon g-2 experiment.
Advisors/Committee Members: Garcia, Alejandro (advisor).
Subjects/Keywords: magnetic field; muons; Physics; Physics
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APA (6th Edition):
Osofsky, R. E. (2020). Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment. (Doctoral Dissertation). University of Washington. Retrieved from http://hdl.handle.net/1773/45255
Chicago Manual of Style (16th Edition):
Osofsky, Rachel Elizabeth. “Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment.” 2020. Doctoral Dissertation, University of Washington. Accessed April 12, 2021.
http://hdl.handle.net/1773/45255.
MLA Handbook (7th Edition):
Osofsky, Rachel Elizabeth. “Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment.” 2020. Web. 12 Apr 2021.
Vancouver:
Osofsky RE. Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment. [Internet] [Doctoral dissertation]. University of Washington; 2020. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/1773/45255.
Council of Science Editors:
Osofsky RE. Magnetic Field Determination for Run 1 of the Fermilab Muon g-2 Experiment. [Doctoral Dissertation]. University of Washington; 2020. Available from: http://hdl.handle.net/1773/45255
Delft University of Technology
7.
Jiang, J. (author).
Design of a Wide-Bandwidth Magnetic Field Sensor.
Degree: 2011, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:806ec550-e6d0-4468-854f-88f0fdbde263
► The combination of Hall sensors and coils can be a practical solution for obtaining a CMOS-compatible contactless current sensor with high bandwidth. A current sensitivity…
(more)
▼ The combination of Hall sensors and coils can be a practical solution for obtaining a CMOS-compatible contactless current sensor with high bandwidth. A current sensitivity of 1mV/A is achieved by the Hall sensors, and the coils have a current sensitivity of about 8mV/A?µs-1. The current sensitivity is influenced by the actual die position inside the package; therefore a more suitable packaging process has to be chosen to maximize the current sensitivity.
Microelectronics, Master of Science
Microelectronics & Computer Engineering
Electrical Engineering, Mathematics and Computer Science
Advisors/Committee Members: Makinwa, K.A.A. (mentor).
Subjects/Keywords: wide-bandwidth; magnetic field sensor
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APA ·
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APA (6th Edition):
Jiang, J. (. (2011). Design of a Wide-Bandwidth Magnetic Field Sensor. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:806ec550-e6d0-4468-854f-88f0fdbde263
Chicago Manual of Style (16th Edition):
Jiang, J (author). “Design of a Wide-Bandwidth Magnetic Field Sensor.” 2011. Masters Thesis, Delft University of Technology. Accessed April 12, 2021.
http://resolver.tudelft.nl/uuid:806ec550-e6d0-4468-854f-88f0fdbde263.
MLA Handbook (7th Edition):
Jiang, J (author). “Design of a Wide-Bandwidth Magnetic Field Sensor.” 2011. Web. 12 Apr 2021.
Vancouver:
Jiang J(. Design of a Wide-Bandwidth Magnetic Field Sensor. [Internet] [Masters thesis]. Delft University of Technology; 2011. [cited 2021 Apr 12].
Available from: http://resolver.tudelft.nl/uuid:806ec550-e6d0-4468-854f-88f0fdbde263.
Council of Science Editors:
Jiang J(. Design of a Wide-Bandwidth Magnetic Field Sensor. [Masters Thesis]. Delft University of Technology; 2011. Available from: http://resolver.tudelft.nl/uuid:806ec550-e6d0-4468-854f-88f0fdbde263
University of Sydney
8.
Yuen, Rai.
Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
.
Degree: 2013, University of Sydney
URL: http://hdl.handle.net/2123/10011
► We reconsider the vacuum-dipole model (VDM) and the corotating-magnetosphere model (CMM) for pulsar electrodynamics. Both the VDM and the CMM are fatally flawed as stand-alone…
(more)
▼ We reconsider the vacuum-dipole model (VDM) and the corotating-magnetosphere model (CMM) for pulsar electrodynamics. Both the VDM and the CMM are fatally flawed as stand-alone models. The former model is used for deriving certain pulsar parameters, such as the surface magnetic field strength and characteristic age, but it lacks the plasma required to emit the observed radiation. The latter model introduces important concepts, such as the Goldreich-Julian charge density and corotation electric field, which form the basis for more detailed models, but it neglects the inductive electric field. When this field is included, the model is unstable to growth of large-amplitude electric oscillations when subject to a temporal perturbation. Furthermore, the predicted highly-relativistic magnetospheric plasma given by the two models is inconsistent with results obtained from observations with the Double Pulsar system. We therefore propose a way of synthesizing the VDM and the CMM for obliquely rotating pulsars. We first modify the VDM to a "minimal" model by assuming that the parallel component of the inductive electric field is screened by charges. We define a class of synthesized models as a linear combination of a fraction y times the minimal model and 1 - y times the CMM. We suggest that the synthesized model provides a basis for understanding the abrupt changes in the magnetospheres of some pulsars, which can alter their slowing down rates. The synthesized model also implies that the velocity of the magnetospheric plasma depends on y and the position of the emission point, which is determined numerically based on the obliquity and viewing angles for emission heights close to stellar surface in dipolar magnetic field structure. We also explore the field structure by including higher order terms in the ratio of the radius to the light-cylinder radius in the magnetic field and explore the implications of these additional terms.
Subjects/Keywords: stars;
magnetic field – pulsars;
general
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Manager
APA (6th Edition):
Yuen, R. (2013). Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
. (Thesis). University of Sydney. Retrieved from http://hdl.handle.net/2123/10011
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):
Yuen, Rai. “Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
.” 2013. Thesis, University of Sydney. Accessed April 12, 2021.
http://hdl.handle.net/2123/10011.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Yuen, Rai. “Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
.” 2013. Web. 12 Apr 2021.
Vancouver:
Yuen R. Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
. [Internet] [Thesis]. University of Sydney; 2013. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/2123/10011.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Yuen R. Pulsar Magnetosphere Revisited: Emission Geometry and the Synthesis of the Vacuum-Dipole and the Rotating-Magnetosphere Models
. [Thesis]. University of Sydney; 2013. Available from: http://hdl.handle.net/2123/10011
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Minnesota
9.
Wahl, Theodore Park.
Planck polarimetry: modeling the galactic magnetic
field.
Degree: MS, Astrophysics, 2010, University of Minnesota
URL: http://purl.umn.edu/93535
► University of Minnesota M.S. thesis. June 2010. Major: Astrophysics. Advisor: Terry J. Jones. 1 computer file (PDF); vii, 30 pages. Ill. (some col.)
I created…
(more)
▼ University of Minnesota M.S. thesis. June 2010.
Major: Astrophysics. Advisor: Terry J. Jones. 1 computer file
(PDF); vii, 30 pages. Ill. (some col.)
I created a model of polarized emission from dust
grains aligned with the galactic magnetic field for comparison with
Planck observations. I modeled the magnetic field in the galactic
disk as a field with a cylindrical constant component and an equal
strength random component. I investigated how the fractional
polarization down a line of sight varies with different models of a
random field. I determine that different models of random fields
yield different amounts of fractional polarization, especially over
sightlines longer than a decorrelation length.
Advisors/Committee Members: Terry J. Jones.
Subjects/Keywords: Polarized emission; Magnetic field; Fractional polarization; Astrophysics
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APA (6th Edition):
Wahl, T. P. (2010). Planck polarimetry: modeling the galactic magnetic
field. (Masters Thesis). University of Minnesota. Retrieved from http://purl.umn.edu/93535
Chicago Manual of Style (16th Edition):
Wahl, Theodore Park. “Planck polarimetry: modeling the galactic magnetic
field.” 2010. Masters Thesis, University of Minnesota. Accessed April 12, 2021.
http://purl.umn.edu/93535.
MLA Handbook (7th Edition):
Wahl, Theodore Park. “Planck polarimetry: modeling the galactic magnetic
field.” 2010. Web. 12 Apr 2021.
Vancouver:
Wahl TP. Planck polarimetry: modeling the galactic magnetic
field. [Internet] [Masters thesis]. University of Minnesota; 2010. [cited 2021 Apr 12].
Available from: http://purl.umn.edu/93535.
Council of Science Editors:
Wahl TP. Planck polarimetry: modeling the galactic magnetic
field. [Masters Thesis]. University of Minnesota; 2010. Available from: http://purl.umn.edu/93535
Cornell University
10.
Schrafel, Peter.
Magnetized Plasma Jets In Experiment And Simulation.
Degree: PhD, Electrical Engineering, 2014, Cornell University
URL: http://hdl.handle.net/1813/38899
► Over five years, this experimental campaign has investigated novel configurations of thin aluminum (Al) foils exploded with intense electric current pulses. These experiments allow for…
(more)
▼ Over five years, this experimental campaign has investigated novel configurations of thin aluminum (Al) foils exploded with intense electric current pulses. These experiments allow for the study of the ablation of thin foils and liners, produce extreme conditions possibly relevant to laboratory astrophysics, and aid in computational code validation. They were carried out with Cornell's COBRA pulser, which drives 1 MA into inductive loads with 100 ns rise time. In these experiments, Ohmic heating of the foil leads to the production of ablated surface plasma (ASP) around the foil. This ASP (ne ~1024 m[-]3 ) near the foil carries some of the load current and develops an overheating-filamentation instability which leads to the development of many (~ 20) warm (~10 eV) plasma tendrils near the foil. This work demonstrates that applying a static or slow
magnetic field (up to 1.5 T over 120 [MICRO SIGN]s) can deflect or suppress these tendrils which carry currents of ~10 kA. The outflow of ASP (with supersonic axial velocities approaching 300 km s[-]1 ) also leads to the creation of a strongly collimated hydrodynamic jet (ne up to 1026 m[-]3 ) on the axis of symmetry. In experiments with an applied axial
field, this outflow compresses the applied Bz on axis (by a factor of 4 in simulation). Compared to the regular jet, the magnetized jet develops more slowly, has a greater angular divergence, and is hollowed on axis (by an order of magnitude). The jet has a radius ~1 mm and an axial extent ~25 mm. This jet behavior has been observed with time-gated pinhole extreme-ultraviolet emission imaging and 532 nm laser interferometry. A spec- ˚ troscopic diagnostic observes Doppler shifts (up to 1 A) in spectral lines (580 nm C-IV doublet) emitted by carbon-seeded ASP 5 mm above the foil (ne ~1023 m[-]3 ) which indicates rotation speeds approaching 50 km s[-]1 with a 1 T applied axial
field. Results from extended-magnetohydrodynamic simulations with the code PERSEUS closely match the experimental results.
Advisors/Committee Members: Kusse, Bruce Raymond (chair), Hammer, David A. (committee member), Lovelace, Richard V E (committee member).
Subjects/Keywords: plasma ablation; current filamentation; magnetic field compression
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APA (6th Edition):
Schrafel, P. (2014). Magnetized Plasma Jets In Experiment And Simulation. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/38899
Chicago Manual of Style (16th Edition):
Schrafel, Peter. “Magnetized Plasma Jets In Experiment And Simulation.” 2014. Doctoral Dissertation, Cornell University. Accessed April 12, 2021.
http://hdl.handle.net/1813/38899.
MLA Handbook (7th Edition):
Schrafel, Peter. “Magnetized Plasma Jets In Experiment And Simulation.” 2014. Web. 12 Apr 2021.
Vancouver:
Schrafel P. Magnetized Plasma Jets In Experiment And Simulation. [Internet] [Doctoral dissertation]. Cornell University; 2014. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/1813/38899.
Council of Science Editors:
Schrafel P. Magnetized Plasma Jets In Experiment And Simulation. [Doctoral Dissertation]. Cornell University; 2014. Available from: http://hdl.handle.net/1813/38899
Rice University
11.
Li, Xinwei.
Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy.
Degree: PhD, Engineering, 2019, Rice University
URL: http://hdl.handle.net/1911/106146
► Cooperative phenomena emerge in condensed matter when interactions between the constituent particles significantly impact, or even govern, the quantum dynamics of the system. The system…
(more)
▼ Cooperative phenomena emerge in condensed matter when interactions between the constituent particles significantly impact, or even govern, the quantum dynamics of the system. The system then exhibits phases and properties that are undescribable by single-particle theories. For understanding the physics behind cooperative phenomena, it is important to disentangle the interplay between different degrees of freedom, including spin, charge, lattice, and orbit. In this dissertation work, we demonstrated that terahertz (THz) magnetospectrosocpy is a powerful tool for probing and elucidating cooperative phenomena in solids by studying four different types of quantum materials. First, we observed a narrow-band THz gain peak in a dense two-dimensional magnetoexciton gas in a photoexcited semiconductor quantum well. Second, by using THz polarimetry, we probed the collective magnetooptical response of surface carriers in a topological insulator in pulsed high
magnetic fields. Third, we detected singular charge fluctuations in a quantum critical heavy-fermion metal in the form of ``ω/T-scaling" in THz conductivity. Finally, we discovered that the exchange coupling between two spin systems in a
magnetic insulator follows the scaling behavior expected for Dicke cooperativity, a well-kown many-body process in quantum optics. The experiments and analyses in these studies can be extended to a variety of other quantum materials for advancing the understanding of many-body physics.
Advisors/Committee Members: Kono, Junichiro (advisor).
Subjects/Keywords: Condensed matter physics; Terahertz spectroscopy; Magnetic field
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Manager
APA (6th Edition):
Li, X. (2019). Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/106146
Chicago Manual of Style (16th Edition):
Li, Xinwei. “Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy.” 2019. Doctoral Dissertation, Rice University. Accessed April 12, 2021.
http://hdl.handle.net/1911/106146.
MLA Handbook (7th Edition):
Li, Xinwei. “Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy.” 2019. Web. 12 Apr 2021.
Vancouver:
Li X. Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy. [Internet] [Doctoral dissertation]. Rice University; 2019. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/1911/106146.
Council of Science Editors:
Li X. Probing Cooperative Phenomena in Solids by Terahertz Magnetospectroscopy. [Doctoral Dissertation]. Rice University; 2019. Available from: http://hdl.handle.net/1911/106146
University of Minnesota
12.
Nelson, Alex.
Magnetic Material Effects On Rf Circuits.
Degree: M.S.E.E., Electrical/Computer Engineering, 2018, University of Minnesota
URL: http://hdl.handle.net/11299/198354
► This thesis discusses the interaction of magnetic materials and high frequency signals inside of microstrip transmission line circuits. This work is based on microstrip circuit…
(more)
▼ This thesis discusses the interaction of magnetic materials and high frequency signals inside of microstrip transmission line circuits. This work is based on microstrip circuit designs that use magnetic materials for either the ground plane and/or as an insert inside the microstrip substrate. The microstrip circuits with inserts are characterized with AC and DC magnetic fields. The magnetic materials are bulk metals. The magnetic materials inserted into the circuit change how the circuit reacts to DC magnetic fields. When a DC magnetic field is applied the transmission of the magnetic materials shifts at each frequency.
Subjects/Keywords: bulk; FMR; magnetic field; microstrip; VNA
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APA (6th Edition):
Nelson, A. (2018). Magnetic Material Effects On Rf Circuits. (Masters Thesis). University of Minnesota. Retrieved from http://hdl.handle.net/11299/198354
Chicago Manual of Style (16th Edition):
Nelson, Alex. “Magnetic Material Effects On Rf Circuits.” 2018. Masters Thesis, University of Minnesota. Accessed April 12, 2021.
http://hdl.handle.net/11299/198354.
MLA Handbook (7th Edition):
Nelson, Alex. “Magnetic Material Effects On Rf Circuits.” 2018. Web. 12 Apr 2021.
Vancouver:
Nelson A. Magnetic Material Effects On Rf Circuits. [Internet] [Masters thesis]. University of Minnesota; 2018. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/11299/198354.
Council of Science Editors:
Nelson A. Magnetic Material Effects On Rf Circuits. [Masters Thesis]. University of Minnesota; 2018. Available from: http://hdl.handle.net/11299/198354
13.
Murugan, Nirosha J.
Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
.
Degree: 2013, Laurentian University
URL: https://zone.biblio.laurentian.ca/dspace/handle/10219/2125
► Planarian maintained in spring water and exposed for two hours to temporally patterned, weak (1 to 5 μT) magnetic field in the dark displayed diminished…
(more)
▼ Planarian maintained in spring water and exposed for two hours to temporally patterned, weak (1 to 5 μT) magnetic field in the dark displayed diminished mobility that simulated the effects of morphine and enhanced this effect at concentrations associated with receptor subtypes. A single (5 hr) exposure to this same pattern following several days of exposure to a very complex patterned field in darkness dissolved the planarian and was associated with an expansion of their volume. Spectral power density analyses of direct measurements of the spring water only following exposure to this field in darkness showed emission spectra that were displayed from control conditions by ~10 nm and associated with an energy increment of ~10-20 J. This value is an intrinsic solution for the physical properties of the water molecule. “Shielding” the exposed water with plastic, aluminum foil or copper foil indicated that only the latter eliminated a powerful spike in photon emission around 280 nm. Continuous measurement of pH indicated that the slow shift towards alkalinity over 12 hours of exposure was associated with enhanced transient pH shifts of .02 units with typical durations between 20 and 40 ms. These results indicate that the appropriately patterned and amplitude of magnetic field that affects water directly could mediate some of the powerful effects displayed by biological aquatic systems.
Subjects/Keywords: Planarian;
Aquesous systems;
spring water;
magnetic field
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APA (6th Edition):
Murugan, N. J. (2013). Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
. (Thesis). Laurentian University. Retrieved from https://zone.biblio.laurentian.ca/dspace/handle/10219/2125
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):
Murugan, Nirosha J. “Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
.” 2013. Thesis, Laurentian University. Accessed April 12, 2021.
https://zone.biblio.laurentian.ca/dspace/handle/10219/2125.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Murugan, Nirosha J. “Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
.” 2013. Web. 12 Apr 2021.
Vancouver:
Murugan NJ. Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
. [Internet] [Thesis]. Laurentian University; 2013. [cited 2021 Apr 12].
Available from: https://zone.biblio.laurentian.ca/dspace/handle/10219/2125.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Murugan NJ. Physical and chemical changes in planarian and non-living aqueous systems from exposure to temporally patterned magnetic fields
. [Thesis]. Laurentian University; 2013. Available from: https://zone.biblio.laurentian.ca/dspace/handle/10219/2125
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Virginia Tech
15.
Cui, Han.
Modeling, Implementation, and Simulation of Two-Winding Plate Inductor.
Degree: PhD, Electrical Engineering, 2017, Virginia Tech
URL: http://hdl.handle.net/10919/78301
► Design of magnetic component is a key factor in achieving high frequency, high power-density converters. Planar magnetics are widely used in bias power supplies for…
(more)
▼ Design of
magnetic component is a key factor in achieving high frequency, high power-density converters. Planar magnetics are widely used in bias power supplies for the benefits of low profile and their compatibility with printed-circuit boards (PCB). The coupled inductors with winding layers sandwiched between two core plates are studied in this dissertation in order to model the self-inductance, winding loss, and core loss.
The most challenging task for the plate-core inductor is to model the
magnetic field with finite core dimensions, very non-uniform flux pattern, and large fringing flux. The winding is placed near the edge of the core to maximize the energy within the limited footprint and the amount of energy stored outside the core volume is not negligible. The proportional-reluctance, equal-flux (PREF) model is developed to build the contours with equal amount of flux by governing the reluctance of the flux path. The shapes of the flux lines are modeled by different functions that guided by the finite-element simulation (FES). The
field from the flux lines enables calculation of inductance, winding loss, and core loss, etc.
The inductance matrix including self-inductance and mutual inductance of a coupled inductor is important for circuit simulation and evaluation. The derivation of the inductance matrix of inductors with plate-core structure is described in Chapter 2. Two conditions are defined as common-mode (CM)
field and differential-mode (DM)
field in order to compute the matrix parameters. The proportional-reluctance, equal-flux (PREF) model introduced is employed to find the CM
field distribution, and the DM
field distribution is found from functions analogous to that of a solenoid's
field. The inductance calculated are verified by flex-circuit prototypes with various dimensions, and the application of the inductance model is presented at the last with normalized parameters to cover structures within a wide-range.
In circuit where coupled inductors are used instead of transformers, the phase shift between the primary and secondary side is not always 180 degrees. Therefore, it is important to model the winding loss for a coupled inductor accurately. The winding loss can be calculated from the resistance matrix, which is independent of excitations but only relates to the frequency and geometry. The methodology to derive the resistance matrix from winding losses of coupled inductors is discussed. Winding loss model with 2D
magnetic field is improved by including the additional eddy current loss for better accuracy for the plate-core structures. The resistance matrix calculated from the model is verified by both measurement results and finite-element simulation (FES) of coupled-inductor prototypes.
Accurate core loss model is required for designing
magnetic components in power converters. Most existing core loss models are based on frequency domain calculation and they cannot be implemented in SPICE simulations. The core loss model in the time domain is discussed in Chapter 5 for arbitrary…
Advisors/Committee Members: Ngo, Khai D. T. (committeechair), Li, Qiang (committee member), Ha, Dong S. (committee member), Lu, Guo Quan (committee member), Guido, Louis J. (committee member).
Subjects/Keywords: magnetic field; plate-core; planar magnetics; inductance
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APA (6th Edition):
Cui, H. (2017). Modeling, Implementation, and Simulation of Two-Winding Plate Inductor. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/78301
Chicago Manual of Style (16th Edition):
Cui, Han. “Modeling, Implementation, and Simulation of Two-Winding Plate Inductor.” 2017. Doctoral Dissertation, Virginia Tech. Accessed April 12, 2021.
http://hdl.handle.net/10919/78301.
MLA Handbook (7th Edition):
Cui, Han. “Modeling, Implementation, and Simulation of Two-Winding Plate Inductor.” 2017. Web. 12 Apr 2021.
Vancouver:
Cui H. Modeling, Implementation, and Simulation of Two-Winding Plate Inductor. [Internet] [Doctoral dissertation]. Virginia Tech; 2017. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/10919/78301.
Council of Science Editors:
Cui H. Modeling, Implementation, and Simulation of Two-Winding Plate Inductor. [Doctoral Dissertation]. Virginia Tech; 2017. Available from: http://hdl.handle.net/10919/78301
University of Leicester
16.
Leyser, Roger P.
Interplanetary magnetic field influence on flux transfer events at Mercury.
Degree: PhD, 2020, University of Leicester
URL: https://doi.org/10.25392/leicester.data.11940306.v1
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803695
► Reconnection between the interplanetary magnetic field (IMF) and Mercury's intrinsic magnetospheric field at the dayside magnetopause drives the Dungey Cycle of magnetic flux. The formation…
(more)
▼ Reconnection between the interplanetary magnetic field (IMF) and Mercury's intrinsic magnetospheric field at the dayside magnetopause drives the Dungey Cycle of magnetic flux. The formation of subsequent evolution of large magnetic structures known as flux transfer events (FTEs) therefore represents an important contribution to magnetospheric dynamics. This thesis presents three studies investigating the factors influencing the rate and location of FTEs, as well as the nature of their subsequent motion and evolution. Flux transfer events in the dayside magnetosphere of Mercury have been visually identified using 12 Mercury years of Magnetometer data from the MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft, covering the period from March 2011 to February 2014. The dependence of the observation rate on the orientation of the IMF in the magnetosheath is investigated, showing a clear preference for FTE formation during periods of southward IMF, and therefore antiparallel reconnection. The locations of the FTE observations have also been analysed along with their direction of motion, in order to investigate the location and orientation of the average reconnection X-line for different IMF orientations. The motions are also used to produce a map showing the convection of the magnetic field in the dayside magnetosphere. Finally, differences in the magnetic field signatures of the observed FTEs with various parameters, including IMF strength and orientation, are probed through the use of superposed epoch analysis. The results provide evidence of FTE rotation with increased distance from the subsolar point, as well as compression of the leading edge of the structure as it moves through the surrounding magnetic field and plasma.
Subjects/Keywords: Thesis; Interplanetary Magnetic Field; Flux Transfer Events
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APA (6th Edition):
Leyser, R. P. (2020). Interplanetary magnetic field influence on flux transfer events at Mercury. (Doctoral Dissertation). University of Leicester. Retrieved from https://doi.org/10.25392/leicester.data.11940306.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803695
Chicago Manual of Style (16th Edition):
Leyser, Roger P. “Interplanetary magnetic field influence on flux transfer events at Mercury.” 2020. Doctoral Dissertation, University of Leicester. Accessed April 12, 2021.
https://doi.org/10.25392/leicester.data.11940306.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803695.
MLA Handbook (7th Edition):
Leyser, Roger P. “Interplanetary magnetic field influence on flux transfer events at Mercury.” 2020. Web. 12 Apr 2021.
Vancouver:
Leyser RP. Interplanetary magnetic field influence on flux transfer events at Mercury. [Internet] [Doctoral dissertation]. University of Leicester; 2020. [cited 2021 Apr 12].
Available from: https://doi.org/10.25392/leicester.data.11940306.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803695.
Council of Science Editors:
Leyser RP. Interplanetary magnetic field influence on flux transfer events at Mercury. [Doctoral Dissertation]. University of Leicester; 2020. Available from: https://doi.org/10.25392/leicester.data.11940306.v1 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.803695
Colorado School of Mines
17.
Osterhout, Samuel.
Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The.
Degree: MS(M.S.), Mechanical Engineering, 2018, Colorado School of Mines
URL: http://hdl.handle.net/11124/172404
► This thesis entails the full development and testing of tri-axially nested square Helmholtz coils. A novel geometric approach is presented which enables the reader to…
(more)
▼ This thesis entails the full development and testing of tri-axially nested square Helmholtz coils. A novel geometric approach is presented which enables the reader to reduce the overall size of the Helmholtz assembly without sacrificing any volume in the workspace. Included in the Appendix of this thesis are all of the mechanical and electrical drawings and bills of materials required for a full-scale reproduction of this project. There, the reader may also find a complete wiring schematic for the system. A comprehensive set of assembly and wiring instructions are provided. Two adaptations of the Biot-Savart law are developed in this paper which offer a means of calculating the B
field, given the position of interest, the coil geometry, and the amount of current passing through the coil. The pseudoinverse is also used to calculate coefficients needed to calibrate the system. The Helmholtz system is capable of producing a
field with a homogeneity of approximately 0.75% given a
field strength to coil radius ratio of 0.219, exceeding performance criteria for typical Helmholtz coil assemblies. System performance is monitored using a three-axis hall magnetometer, the setup and results of which are presented and used to validate the system geometry and both approximation methods presented. For an outline of the overall system functionality, this paper details the structure of code written for system development and testing. This is accompanied by a discussion of the graphical user interface written for controlling and monitoring system performance.
Advisors/Committee Members: Petruska, Andrew J. (advisor), Petrella, Anthony J. (committee member), Zhang, Hao (committee member), Han, Qi (committee member).
Subjects/Keywords: gradient; homogeneous; magnetism; Helmholtz; field; magnetic
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APA (6th Edition):
Osterhout, S. (2018). Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The. (Masters Thesis). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/172404
Chicago Manual of Style (16th Edition):
Osterhout, Samuel. “Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The.” 2018. Masters Thesis, Colorado School of Mines. Accessed April 12, 2021.
http://hdl.handle.net/11124/172404.
MLA Handbook (7th Edition):
Osterhout, Samuel. “Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The.” 2018. Web. 12 Apr 2021.
Vancouver:
Osterhout S. Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The. [Internet] [Masters thesis]. Colorado School of Mines; 2018. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/11124/172404.
Council of Science Editors:
Osterhout S. Design, assembly, programming, and testing of triaxially-nested Helmholtz coils, The. [Masters Thesis]. Colorado School of Mines; 2018. Available from: http://hdl.handle.net/11124/172404
18.
Dutra, Eric C.
Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy.
Degree: 2019, University of Nevada – Reno
URL: http://hdl.handle.net/11714/5711
► Plasma is the most abundant form of visible matter in the universe. Plasmas make up approximately 99 percent of stellar objects observed including billions of…
(more)
▼ Plasma is the most abundant form of visible matter in the universe. Plasmas make up approximately 99 percent of stellar objects observed including billions of stars and nebulae. High-energy-density (HED) physics is a rapidly growing area of physics that encompasses several disciplines including plasma-, condensed-matter-, nuclear- and astro-physics. Several important HED physics topics are currently active areas of research and include efforts to understand fundamental mechanisms driving magnetized plasma dynamics and radiative properties of magnetized plasmas. Experimental investigations aim to provide data needed to more accurately model details of the plasma evolution such as how currents flow within the plasma and how current symmetries affect
magnetic fields. Plasma properties are usually determined from diagnostics that measure
magnetic field strengths, photon emission and particle radiation, to name a few.In this dissertation, investigations of the temporal evolution of magnetically driven plasmas is presented. These studies were carried at the Nevada Terawatt Facility using the Zebra pulsed-power accelerator to magnetically compresses and confine a cylindrical plasma column. Important parameters needed to characterize these laboratory plasmas include
magnetic field strength and orientation, as well as electron number density and temperature. To fully understand the characteristics of a plasma, accurate experimental measurement of these parameters is essential. To determine the electron temperature, the Boltzmann plot method was used. Simulated spectra from PrismSPECT where compared to experimental measurements in order to measure electron number density and temperature early in the pinched plasma formation. Simultaneously, Mach-Zehnder laser interferometry was used to provide complementary measurements of the electron number density. A novel method, streaked Zeeman-induced
Magnetic Splitting (ZIMS) optical spectroscopy, was developed to measure time- and space-resolved
magnetic field strengths in these hot, dense plasmas. This technique has also been applied to diagnose the
magnetic field strengths in laser ablation Z-pinch experiments (LAZE), wherein a pulsed power driver pinches a laser ablated plume. To effectively utilize ZIMS, ionic plasma species were chosen such that the Zeeman splitting of different fine structure doublets occurs non-uniformly with increasing
magnetic field strength in the plasma. A streak camera was then used to continuously observe spectroscopically resolved differential splitting from a well-defined spatial region in the plasma, and analysis of the measurements was used to determine non-directional
magnetic field strengths with increasing plasma temperature and density. In parallel, we have developed a spectral line emission modeling code for ZIMS. The initial line shape parameters input into the code were varied to simulate emission spectra observed, and the fitting parameters were adjusted iteratively until an acceptable fit was achieved. These results were then used to…
Advisors/Committee Members: Covington, Aaron M. (advisor), Mancini, Roberto C. (committee member), Ivanov, Vladimir V. (committee member), Casey, Sean M. (committee member), Presura, Radu (committee member), Rawat, Banmali (committee member).
Subjects/Keywords: Magnetic field; Plasma; Spectroscopy; Zeeman; Z-pinch
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APA (6th Edition):
Dutra, E. C. (2019). Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy. (Thesis). University of Nevada – Reno. Retrieved from http://hdl.handle.net/11714/5711
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):
Dutra, Eric C. “Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy.” 2019. Thesis, University of Nevada – Reno. Accessed April 12, 2021.
http://hdl.handle.net/11714/5711.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Dutra, Eric C. “Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy.” 2019. Web. 12 Apr 2021.
Vancouver:
Dutra EC. Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy. [Internet] [Thesis]. University of Nevada – Reno; 2019. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/11714/5711.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Dutra EC. Investigations of plasma evolution in Laser Ablation Z-Pinch Experiments using Time-Resolved Optical Spectroscopy. [Thesis]. University of Nevada – Reno; 2019. Available from: http://hdl.handle.net/11714/5711
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
19.
van Aert, Emy (author).
Gel dosimetry for a MR-linac: magnetic field and time dependency.
Degree: 2020, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:4408f7c6-d16f-4cab-90c0-60dbf03d8a27
► The goal of this research was to perform a 3D end-to-end test on a MR-linac to check the whole workflow using a clinical treatment plan.…
(more)
▼ The goal of this research was to perform a 3D end-to-end test on a MR-linac to check the whole workflow using a clinical treatment plan. Dosimetric gel was used to obtain 3D spatial information, with the phantom in the same position for irradiation and scanning. In order to achieve this, fundamental elements of gel dosimetry needed to be investigated. In the MR-linac, irradiation is delivered in the presence of a permanent
magnetic field. Therefore, the dosimetric response within a 1.5 T
magnetic field should be validated. It is also important to investigate the time-dependence of the gel. It is preferable to read-out the gels within approximately one hour, so that the phantom does not have to be moved. Ideally, scanning and irradiation would be done at the same time, to see the dynamical dose delivery. The VIPAR gel was used for this research. The experiments demonstrated that R2 values for doses irradiated with
magnetic field were the same as R2 values for the same dose irradiated without
magnetic field. R2 values are still proportional to the dose. It was also shown that it is possible to scan the phantom within 20 minutes after irradiation. Sensitivity is at its highest after approximately 8 hours and stays stable afterwards, so scanning after 8 hours will improve the read-out accuracy. It was also possible to make a fit for the R2 versus time plots, which makes it possible to correct for change over time. The fit can be divided in two linear parts if time is plotted on a logarithmic scale, one fit for the time points before 7 hours, one for the time points after 7 hours. The partial doses acquired by the gel during radiation delivery were estimated. The equivalent R2 values then agreed with the extrapolated fit to within 4%. This is a good indication that dynamic gel (4D) dosimetry may be achievable. A protocol for a relative end-to-end test was also developed. From the preliminary results, it appeared that a relative end-to-end test can be performed with the read-out of gel within 1 hour. A new MR sequence needs to be developed. For this end-to-end test, the sequence needs to scan a larger volume with a higher resolution, therefore, the scan time will increase and real-time dosimetry will not be possible. Changing the MR sequence might also change the optimal irradiation-scanning interval and the R2 versus time curve. To perform absolute dosimetry, an extra calibration would be required.
Advisors/Committee Members: Denkova, Antonia (mentor), Wolthaus, Jochem (mentor), Woodings, Simon (mentor), Schaart, Dennis (graduation committee), Djanashvili, Kristina (graduation committee), Delft University of Technology (degree granting institution).
Subjects/Keywords: gel dosimetry; MR-linac; magnetic field
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APA (6th Edition):
van Aert, E. (. (2020). Gel dosimetry for a MR-linac: magnetic field and time dependency. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:4408f7c6-d16f-4cab-90c0-60dbf03d8a27
Chicago Manual of Style (16th Edition):
van Aert, Emy (author). “Gel dosimetry for a MR-linac: magnetic field and time dependency.” 2020. Masters Thesis, Delft University of Technology. Accessed April 12, 2021.
http://resolver.tudelft.nl/uuid:4408f7c6-d16f-4cab-90c0-60dbf03d8a27.
MLA Handbook (7th Edition):
van Aert, Emy (author). “Gel dosimetry for a MR-linac: magnetic field and time dependency.” 2020. Web. 12 Apr 2021.
Vancouver:
van Aert E(. Gel dosimetry for a MR-linac: magnetic field and time dependency. [Internet] [Masters thesis]. Delft University of Technology; 2020. [cited 2021 Apr 12].
Available from: http://resolver.tudelft.nl/uuid:4408f7c6-d16f-4cab-90c0-60dbf03d8a27.
Council of Science Editors:
van Aert E(. Gel dosimetry for a MR-linac: magnetic field and time dependency. [Masters Thesis]. Delft University of Technology; 2020. Available from: http://resolver.tudelft.nl/uuid:4408f7c6-d16f-4cab-90c0-60dbf03d8a27
Queen Mary, University of London
20.
Zhang, Tingting.
Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors.
Degree: PhD, 2017, Queen Mary, University of London
URL: http://qmro.qmul.ac.uk/xmlui/handle/123456789/24854
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765927
► The research area of magnetic field effects (MFE) on organic systems has been intensively studied during the last decade. It has been revealed that there…
(more)
▼ The research area of magnetic field effects (MFE) on organic systems has been intensively studied during the last decade. It has been revealed that there are processes that are subject to low fields (< 50 mT) and processes that are subject to high fields (> 50 mT). While the low field processes are widely accepted to be a result of the suppression of the spin mixing caused by random hyperfine fields and spin-orbit coupling within the devices, the origin of the high field processes is still not clear. Although several mechanisms, like triplet-charge carrier interaction (TCI) and triplet-triplet annihilation (TTA), were proposed to explain the high field MFEs, how these processes are affected by a magnetic field is not well understood. This thesis presents a study of the role of excitons on MFEs using aluminium tris(8-hydroxyquinolinate) (Alq3) based diodes, focusing on the behaviour of high field effects on electroluminescence (MEL). In order to investigate the role of excitons on high field MEL, devices with different structures were designed to modify the population of exciton and excess charge carriers in the devices via controlling the injection of charge carriers. In this way, the exciton population dependent TTA and TCI processes can be studied further and even distinguished, since the TTA depends mainly on the population of triplets while the TCI depends on the exciton to charge carrier ratio. Steady state MFE measurements were performed, and results show that significant high field MEL decay can be seen in a device with extremely low triplet concentration. This indicates that TTA cannot be the underlying mechanism of high field MEL decay. The gradual trend of high field MEL, changing from a moderate increase to significant decays upon adjusting the hole and electron injection from balanced to severely hole dominated, suggests that this high field decay is exciton-hole interaction dependent. To decompose the role of singlets and triplets on high MELs, transient MFE measurements were performed on the Alq3 based standard devices. Since in Alq3 layer singlets feature a lifetime of ~ns and triplets feature a lifetime of ~ms, the behaviour of MEL at the rising edge and the falling edge of a pulse can provide a useful tool. Results show that an extra component occurs in the transient MEL at large current density and high fields. This indicates that the high field MEL is related to triplet-charge carrier interaction.
Subjects/Keywords: 621.3815; Physics and Astronomy; magnetic field effects
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APA (6th Edition):
Zhang, T. (2017). Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors. (Doctoral Dissertation). Queen Mary, University of London. Retrieved from http://qmro.qmul.ac.uk/xmlui/handle/123456789/24854 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765927
Chicago Manual of Style (16th Edition):
Zhang, Tingting. “Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors.” 2017. Doctoral Dissertation, Queen Mary, University of London. Accessed April 12, 2021.
http://qmro.qmul.ac.uk/xmlui/handle/123456789/24854 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765927.
MLA Handbook (7th Edition):
Zhang, Tingting. “Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors.” 2017. Web. 12 Apr 2021.
Vancouver:
Zhang T. Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors. [Internet] [Doctoral dissertation]. Queen Mary, University of London; 2017. [cited 2021 Apr 12].
Available from: http://qmro.qmul.ac.uk/xmlui/handle/123456789/24854 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765927.
Council of Science Editors:
Zhang T. Investigating exciton-polaron interactions and their effect on high magnetic field effects in organic semiconductors. [Doctoral Dissertation]. Queen Mary, University of London; 2017. Available from: http://qmro.qmul.ac.uk/xmlui/handle/123456789/24854 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.765927
University of Oulu
21.
Getachew, T. (Tibebu).
Spatial-temporal structure and distribution of the solar photospheric magnetic field.
Degree: 2019, University of Oulu
URL: http://urn.fi/urn:isbn:9789526224367
► Abstract I have made a detailed study of the fundamental properties of the solar photospheric magnetic field, which helps in better understanding the Sun’s radiative…
(more)
▼ Abstract
I have made a detailed study of the fundamental properties of the solar photospheric
magnetic field, which helps in better understanding the Sun’s radiative and particle outputs that affect the Earth’s near-space environment, as well as the entire heliosphere. Photospheric
magnetic field is an essential parameter for space weather and space climate. The photospheric
magnetic field includes a wide range of large-scale and small-scale structures, but the contribution of weak, small-scale fields to the total flux on the solar surface is dominant.
This thesis discusses the spatial-temporal structure and long-term evolution of the solar photospheric
magnetic field. Particularly, the thesis presents, for the first time, the spatial distribution of the asymmetry of weak
field values and its evolution in solar cycles 21–24. I found that the asymmetry (also called shift) of the distribution of positive and negative weak-
field values is a real physical phenomenon. I also found that the shifts are most effectively produced at the supergranulation scale.
I studied the asymmetry of the distribution of weak
field values separately in the two solar hemispheres. My results show that the shifts of weak-
field field distributions in the two solar hemispheres have always the same sign as the new polarity of the polar
field in the respective hemisphere and solar cycle. I also found that the hemispheric shifts change their sign in the late ascending to maximum phase of the solar cycle and attain their maximum in the early to mid-declining phase. This evolution of the hemispheric weak-
field gives a new signal of the solar
magnetic cycle.
We also studied the long-term spatial-temporal evolution of the weak-
field shift and skewness of the distribution of photospheric
magnetic field values during solar cycles 21–24 in order to clarify the role and relation of the weak
field values to the overall
magnetic field evolution. Our results give evidence for the preference of even the weakest
field elements toward the prevailing
magnetic polarity since the emergence of an active region, and for a systematic coalescence of stronger
magnetic fields of opposite to produce weak fields during the poleward drift of the surge.
Advisors/Committee Members: Mursula, K. (Kalevi), Virtanen, I. (Ilpo).
Subjects/Keywords: photospheric magnetic field; solar activity; space climate
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APA (6th Edition):
Getachew, T. (. (2019). Spatial-temporal structure and distribution of the solar photospheric magnetic field. (Doctoral Dissertation). University of Oulu. Retrieved from http://urn.fi/urn:isbn:9789526224367
Chicago Manual of Style (16th Edition):
Getachew, T (Tibebu). “Spatial-temporal structure and distribution of the solar photospheric magnetic field.” 2019. Doctoral Dissertation, University of Oulu. Accessed April 12, 2021.
http://urn.fi/urn:isbn:9789526224367.
MLA Handbook (7th Edition):
Getachew, T (Tibebu). “Spatial-temporal structure and distribution of the solar photospheric magnetic field.” 2019. Web. 12 Apr 2021.
Vancouver:
Getachew T(. Spatial-temporal structure and distribution of the solar photospheric magnetic field. [Internet] [Doctoral dissertation]. University of Oulu; 2019. [cited 2021 Apr 12].
Available from: http://urn.fi/urn:isbn:9789526224367.
Council of Science Editors:
Getachew T(. Spatial-temporal structure and distribution of the solar photospheric magnetic field. [Doctoral Dissertation]. University of Oulu; 2019. Available from: http://urn.fi/urn:isbn:9789526224367
University of Oulu
22.
Virtanen, I. (Iiro).
Surface flux transport simulations of the photospheric magnetic field.
Degree: 2019, University of Oulu
URL: http://urn.fi/urn:isbn:9789526223292
► Abstract This thesis studies the long-term evolution of the photospheric magnetic field using surface flux transport simulations. The photospheric magnetic field and magnetic activity are…
(more)
▼ Abstract
This thesis studies the long-term evolution of the photospheric
magnetic field using surface flux transport simulations. The photospheric
magnetic field and
magnetic activity are tightly connected to space weather, and affect the whole heliosphere including the Earth. However, due to a lack of reliable observations our understanding of the long-term evolution of the photospheric
magnetic field is still poor. Surface flux transport models, which are capable of simulating the evolution of the whole surface
field from observations of solar activity, can be used to study the
field in times when direct observations are not available.
In this thesis we validate our surface flux transport model, optimize its parameters and test its sensitivity to uncertainties in parameter values and input data. We find a need to extend the model with a decay term to properly model the deep and long minimum between solar cycles 23 and 24, and simulate the photospheric
magnetic field of cycles 21–24 using magnetographic observations as input. We also study consequences of hemispherically asymmetric activity, and show that activity in one hemisphere is enough to maintain polar fields in both hemispheres through cross-equatorial flow of
magnetic flux.
We develop a new method to reconstruct active regions from calcium K line and sunspot polarity observations. We show that this reconstruction is able to accurately capture the correct axial dipole moment of active regions. We study the axial dipole moments of observed active regions and find that a significant fraction of them have a sign opposite to the sign expected from Hale’s and Joy’s laws, proving that the new reconstruction method has an advantage over existing methods that rely on Hale’s and Joy’s laws to define polarities. We show one example of a long simulation covering solar cycles 15–21, demonstrating that using the active region reconstruction and surface flux transport model presented in this thesis it is possible to simulate the large-scale evolution of the photospheric
magnetic field over the past century.
Advisors/Committee Members: Mursula, K. (Kalevi), Pevtsov, A. (Alexei).
Subjects/Keywords: Photosphere; Solar activity; Solar magnetic field
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APA (6th Edition):
Virtanen, I. (. (2019). Surface flux transport simulations of the photospheric magnetic field. (Doctoral Dissertation). University of Oulu. Retrieved from http://urn.fi/urn:isbn:9789526223292
Chicago Manual of Style (16th Edition):
Virtanen, I (Iiro). “Surface flux transport simulations of the photospheric magnetic field.” 2019. Doctoral Dissertation, University of Oulu. Accessed April 12, 2021.
http://urn.fi/urn:isbn:9789526223292.
MLA Handbook (7th Edition):
Virtanen, I (Iiro). “Surface flux transport simulations of the photospheric magnetic field.” 2019. Web. 12 Apr 2021.
Vancouver:
Virtanen I(. Surface flux transport simulations of the photospheric magnetic field. [Internet] [Doctoral dissertation]. University of Oulu; 2019. [cited 2021 Apr 12].
Available from: http://urn.fi/urn:isbn:9789526223292.
Council of Science Editors:
Virtanen I(. Surface flux transport simulations of the photospheric magnetic field. [Doctoral Dissertation]. University of Oulu; 2019. Available from: http://urn.fi/urn:isbn:9789526223292
University of Michigan
23.
Yu, Fan.
The Torque Magnetometry Study of Underdoped YBa2Cu3Oy.
Degree: PhD, Physics, 2017, University of Michigan
URL: http://hdl.handle.net/2027.42/140803
► This thesis describes torque magnetometry study on under-doped YBa2Cu3Oy (YBCO). Torque magnetometry measures the anisotropic magnetization of materials, and is among the most sensitive experimental…
(more)
▼ This thesis describes torque magnetometry study on under-doped YBa2Cu3Oy (YBCO). Torque magnetometry measures the anisotropic magnetization of materials, and is among the most sensitive experimental methods to probe superconducting state. This study's motivation is to apply this method to the open question: how much does the superconducting fluctuations persist into the pseudogap region, where various ordered states are observed?
Experiments at temperatures close to and above Tc was conducted. Diamagnetic component was extracted from the samples' observed magnetization. The result was in agreement with the theory as well as previous study on different under-doped superconducting cuprates. These evidence indicates that the superconducting fluctuations persist deeply into the pseudogap region (quantitative detail see Chapter.3).
Furthermore, torque magnetometry was successfully conducted with superconducting samples with Tc ~ 62 K, at temperatures one order of magnitude lower than Tc and DC
magnetic field upto 45 Tesla. Before this, torque magnetometry experiment on underdoped cuprates was never conducted so deeply inside the superconducting dome. A "kink'' feature, shown as abnormal behavior in magnetization and more clearly revealed as a peak in differentiated susceptibility dM/dB, was observed at temperatures below 40 K, once the superconducting state with long range coherence was suppressed by strong
magnetic field.
The "kink'' feature has either a two dimensional or highly anisotropic origin along the ab-plane, and demonstrated very weak temperature dependence. Comparisons with results by thermal conductivity, X-ray scattering, nuclear
magnetic resonance (NMR) and ultrasonic methods were made. Apparently, the "kink'' feature shows up on phase diagram in the same region where the charge density wave (CDW) transition was known to exist. Thus, it is suspected that the "kink'' feature is originated from the superconducting fluctuations influenced by a CDW related transition.
The observation of the ``kink'' feature, combined with results on diamagnetism and our collaborators' results on thermal conductivity, we are able to rule out a previous estimation of Hc2 that is misleadingly low in
magnetic field and/or temperature.
Finally, efforts to extend torque magnetometry method to pulsed
magnetic field were introduced.
Since the highest available DC
magnetic field is limited to 45 Tesla, AC
magnetic field which could reach 65 Tesla is the only choice for experiments aimed at the deeper parts of the superconducting dome. The situations and their unique challenges, as well as our preliminary results were analyzed in detail.
Advisors/Committee Members: Li, Lu (committee member), Liang, Xiaogan (committee member), Sih, Vanessa (committee member), Sun, Kai (committee member), Zhao, Liuyan (committee member).
Subjects/Keywords: high temperature superconductor; pseudogap region; high magnetic field; pulsed magnetic field; magnetometry; Physics; Science
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APA (6th Edition):
Yu, F. (2017). The Torque Magnetometry Study of Underdoped YBa2Cu3Oy. (Doctoral Dissertation). University of Michigan. Retrieved from http://hdl.handle.net/2027.42/140803
Chicago Manual of Style (16th Edition):
Yu, Fan. “The Torque Magnetometry Study of Underdoped YBa2Cu3Oy.” 2017. Doctoral Dissertation, University of Michigan. Accessed April 12, 2021.
http://hdl.handle.net/2027.42/140803.
MLA Handbook (7th Edition):
Yu, Fan. “The Torque Magnetometry Study of Underdoped YBa2Cu3Oy.” 2017. Web. 12 Apr 2021.
Vancouver:
Yu F. The Torque Magnetometry Study of Underdoped YBa2Cu3Oy. [Internet] [Doctoral dissertation]. University of Michigan; 2017. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/2027.42/140803.
Council of Science Editors:
Yu F. The Torque Magnetometry Study of Underdoped YBa2Cu3Oy. [Doctoral Dissertation]. University of Michigan; 2017. Available from: http://hdl.handle.net/2027.42/140803
Northeastern University
24.
Abdi, Hamed.
Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields.
Degree: PhD, Department of Mechanical and Industrial Engineering, 2018, Northeastern University
URL: http://hdl.handle.net/2047/D20316385
► We present computer simulations on dilute suspensions of superparamagnetic particles subjected to rotating magnetic fields. We focus on short chains of particles and their decay…
(more)
▼ We present computer simulations on dilute suspensions of superparamagnetic particles subjected to rotating magnetic fields. We focus on short chains of particles and their decay routes to stable orbits. We show that, surprisingly, the value of the magnetic susceptibility qualitatively affects the chain dynamics. At low susceptibility, as we increase the field rotation rate, two bifurcations in the dynamical response appear. Below the first bifurcation, the chains track the external field orientation as a rigid body. Between the two bifurcations, the chains periodically fragment and reform. We call this do-si-do motion. Above the second bifurcation, the transient response is a chaotic motion finally collapsing at long times to a rotating close-packed planar cluster. We show that the transition out of the chaotic states can be described as a Poisson process in both simulation and experiment. At intermediate susceptibility, as we further increase the rate, a third bifurcation emerges. Above the third bifurcation, the transient chaotic motion is suppressed. The particles preserve the chain state but demonstrate a periodic oscillatory motion. We call these orbits stick-slip chains. At high susceptibility, the close-packed clusters and the do-si-do orbits disappear. As we increase the rate, we observe only one bifurcation in the dynamical response: from rigid body rotation below to a stick-slip chain above. The existence of the stick-slip chains and the resilience of extended rotating structures at high field rotation rate has important implications for applications such as field-driven flows and mixing, and we hope the results motivate further experiments, theory, and modeling in this regime.
Subjects/Keywords: Bifurcation point; Dilute Suspensions; Field rotation rate; Magnetic Field; Magnetic susceptibility; Paramagnetic Colloids; Mechanical engineering
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APA (6th Edition):
Abdi, H. (2018). Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields. (Doctoral Dissertation). Northeastern University. Retrieved from http://hdl.handle.net/2047/D20316385
Chicago Manual of Style (16th Edition):
Abdi, Hamed. “Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields.” 2018. Doctoral Dissertation, Northeastern University. Accessed April 12, 2021.
http://hdl.handle.net/2047/D20316385.
MLA Handbook (7th Edition):
Abdi, Hamed. “Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields.” 2018. Web. 12 Apr 2021.
Vancouver:
Abdi H. Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields. [Internet] [Doctoral dissertation]. Northeastern University; 2018. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/2047/D20316385.
Council of Science Editors:
Abdi H. Dilute Suspensions Of Paramagnetic Colloids In Rotating Fields. [Doctoral Dissertation]. Northeastern University; 2018. Available from: http://hdl.handle.net/2047/D20316385
Rice University
25.
Hsu, Chien.
Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field.
Degree: MS, Engineering, 2016, Rice University
URL: http://hdl.handle.net/1911/96536
► Magnetic swimmers have been studied with the purpose of applying them to mimic the motion of organisms in fluids. Clusters formed by self-assembled magnetic particles…
(more)
▼ Magnetic swimmers have been studied with the purpose of applying them to mimic the motion of organisms in fluids. Clusters formed by self-assembled
magnetic particles is one the possible approaches for that purpose. A considerable amount of effort has been made on applying uniaxial, biaxial, and triaxial
magnetic fields to study self-assembled clusters. For the case where biaxial
magnetic fields are applied, a circular rotational
magnetic (CRM)
field is usually adopted. Relevant results concerning the behavior of these clusters in eccentric rotational
magnetic (ERM) fields are limited. This may be due to the limited number of stable conformations formed in such a
magnetic field is linear. In this thesis, we show that several unique metastable cluster structures can form in an ERM
field. The clusters are formed by applying a CRM
field to a dispersion containing paramagnetic particles to form a specific configuration and then the
magnetic field is switched to an ERM those
field to visualize new dynamics. These 2-D clusters can be driven by the applied
magnetic field, yielding an appreciable net displacement, and exhibit specific dynamic behavior. The behavior of these clusters is influenced by the surface charge of the comprising
magnetic particles, the strength and the frequency of the applied
magnetic field, and the viscosity of the dispersion fluid. A model is proposed to simulate the phenomena observed in the experiment which describes successfully the displacement of a pentamer colloidal cluster.
Advisors/Committee Members: Biswal, Sibani Lisa (advisor).
Subjects/Keywords: Magnetic Clusters; Eccentric Rotational Magnetic Field; Self-assembly
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APA (6th Edition):
Hsu, C. (2016). Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field. (Masters Thesis). Rice University. Retrieved from http://hdl.handle.net/1911/96536
Chicago Manual of Style (16th Edition):
Hsu, Chien. “Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field.” 2016. Masters Thesis, Rice University. Accessed April 12, 2021.
http://hdl.handle.net/1911/96536.
MLA Handbook (7th Edition):
Hsu, Chien. “Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field.” 2016. Web. 12 Apr 2021.
Vancouver:
Hsu C. Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field. [Internet] [Masters thesis]. Rice University; 2016. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/1911/96536.
Council of Science Editors:
Hsu C. Moving of Magnetic Clusters Driven by an Applied Eccentric Rotational Magnetic Field. [Masters Thesis]. Rice University; 2016. Available from: http://hdl.handle.net/1911/96536
King Abdullah University of Science and Technology
26.
Bajaber, Bashaer.
A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells.
Degree: Biological and Environmental Sciences and Engineering (BESE) Division, 2020, King Abdullah University of Science and Technology
URL: http://hdl.handle.net/10754/662810
► Mesenchymal stem cells (MSCs) are the most widely used source for bone tissue engineering due to their capability of multipotent differentiation. The use of nanotechnology…
(more)
▼ Mesenchymal stem cells (MSCs) are the most widely used source for bone tissue engineering due to their capability of multipotent differentiation. The use of nanotechnology in biomedical applications and therapy has increased in recent years provides an elegant alternative in comparison to current tissue engineering methods.
Magnetic nanowires have a high potential in the medical
field, as they are biocompatible, are simple to fabricate, possess low cytotoxic effects and can be operated wirelessly via
magnetic fields. A nanowire substrate (NW) can provide a surface with tunable elastic properties. Therefore,
magnetic nanowires have many promising applications such as in cell therapy, cell separation, cancer treatment, and as a scaffold for cell culture.
This thesis explores the effects of alternating
magnetic field (AMF) as a biophysical stimulator of osteogenic differentiation of MSCs by culturing the stem cells on a
magnetic iron (Fe) NW. To this end, Fe nanowires were fabricated through electrodeposition and interactions between the NW and cells were analysed by electron microscopy. An AMF was applied to the NW in order to induce a vibration. MSCs were exposed to different
magnetic field intensities, 250 mT and 50 mT, for different application times, 12 hours on followed by 12 hours off for two days and 24 hours on followed by 12 hours off. Differentiation was determined through the assessment of osteogenic markers at the mRNA level by RT-PCR and at the protein level by flow cytometry and fluorescence microscopy. Different effects were observed on MSCs grown on Fe NWs following exposure to different
magnetic field intensities and duration applications. MSC differentiation towards the osteogenic lineage increased with increased
field intensities. The most enhanced osteogenic differentiation of MSCs was observed at 250 mT AMF for 12 hours, as evidenced by elevated osteogenic markers at mRNA level compared to that of an AMF free control. Based on these results, we proposed that culturing MSCs on
magnetic nanomaterials has the potential to control and promote osteogenesis under
magnetic field and without the addition of external differentiation factors. These findings provide a new tool for stem cell research as an effective technology for bone tissue engineering and regenerative medicine.
Advisors/Committee Members: Kosel, Jürgen (advisor), Merzaban, Jasmeen (committee member), Saikaly, Pascal (committee member).
Subjects/Keywords: Magnetic nanowires; Magnetic field; Mesenchymal stem cells; Osteogenic differentiation
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APA (6th Edition):
Bajaber, B. (2020). A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/662810
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):
Bajaber, Bashaer. “A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells.” 2020. Thesis, King Abdullah University of Science and Technology. Accessed April 12, 2021.
http://hdl.handle.net/10754/662810.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Bajaber, Bashaer. “A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells.” 2020. Web. 12 Apr 2021.
Vancouver:
Bajaber B. A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2020. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/10754/662810.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Bajaber B. A Magnetic Nanowire Substrate to Induce Osteogenic Differentiation of Mesenchymal Stem Cells. [Thesis]. King Abdullah University of Science and Technology; 2020. Available from: http://hdl.handle.net/10754/662810
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
27.
Lungaro, Lisa.
Development and utility of magnetic nanoparticles production by mammalian cells.
Degree: PhD, 2018, University of Edinburgh
URL: http://hdl.handle.net/1842/31074
► Magnetic hyperthermia (MH) is an anti-cancer treatment which exploits the heat produced by tumour-targeted magnetic nanoparticles (MNPs) subjected to an alternating magnetic field (AMF). A…
(more)
▼ Magnetic hyperthermia (MH) is an anti-cancer treatment which exploits the heat produced by tumour-targeted magnetic nanoparticles (MNPs) subjected to an alternating magnetic field (AMF). A problem limiting the clinical use of MH, however, is the inability to adequately localise the MNPs at the tumour site. A cellular approach using mesenchymal stem cells (MSCs) as carriers has been proposed as these cells are believed to home to sites of tissue injury and tumour growth, however problems with MNPs uptake and toxicity retard progress and need to be overcome. The aim of this project was to find an alternative approach in MH treatment, creating engineered human MSCs able to biosynthesise MNPs. To achieve this goal, MSCs were transfected with either, or both, M. magneticum AMB-1 mms6 and mmsF genes. M. magneticum AMB-1 is a genus of magnetotactic bacteria, containing magnetosomes, which are lipidic organelles containing single crystals of magnetite. M. magneticum-AMB1 mms6 and mmsF genes are important for final crystal morphology and are known to play a role in crystal synthesis and growth respectively. The originality of this study was in using mms6 and mmsF genes, which were codon-optimized for mammalian expression, alone or in combination, for transfection of human MSCs, which have known tumour homing capacity. The transfected MNPs-bearing MSCs, able to migrate into the tumour tissue, were subjected to AMF in MH experiments in an attempt to induce cancer cell death. mms6 and mmsF gene expression, following transfection, was investigated in the human osteosarcoma cell line MG63 by reverse transcription polymerase chain reaction (RT-PCR). The cellular ultrastructure of transfected MG63 cells was investigated by transmission electron microscopy (TEM), revealing the presence of nanoparticles. The magnetism of transfected MG63 cells was proved by superconducting quantum interference device (SQUID) and supported by in vitro MH experiments. Then, human MSCs were transfected with mms6 and mmsF genes, alone or in combination. The effect of transfection experiments and MNPs synthesis on MSCs markers of stemness, cell proliferation and differentiation ability were investigated. The MTB genes expression in human MSCs was assessed by RT-PCR and cell magnetism was confirmed by SQUID, in vitro MH experiments and by magnetic force microscopy (MFM). Then, in vitro studies of MH were undertaken to establish whether mms6 transfected MSCs expressing MNPs supported a MH effect when exposed to an AMF. Cells were initially exposed to an AMF of 565.3 kHz frequency in monolayers and in 3D arrangements and cell death/viability was assessed. Subsequently, the effect of the same AMF on 3D models of mixed populations of mms6-expressing MSCs and cancer cells was assessed. The results indicate that viability of MNPs-expressing MSCs and adjacent cancer cells is reduced following AMF exposure. In vivo studies of MH were undertaken following intracardiac injection of mms6-expressing MSCs in tumour-bearing mice (epidermoid carcinoma). The expression of…
Subjects/Keywords: 616.99; magnetic hyperthermia; magnetic nanoparticles; alternating magnetic field; mesenchymal stem cells; magnetotactic bacteria
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APA ·
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APA (6th Edition):
Lungaro, L. (2018). Development and utility of magnetic nanoparticles production by mammalian cells. (Doctoral Dissertation). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/31074
Chicago Manual of Style (16th Edition):
Lungaro, Lisa. “Development and utility of magnetic nanoparticles production by mammalian cells.” 2018. Doctoral Dissertation, University of Edinburgh. Accessed April 12, 2021.
http://hdl.handle.net/1842/31074.
MLA Handbook (7th Edition):
Lungaro, Lisa. “Development and utility of magnetic nanoparticles production by mammalian cells.” 2018. Web. 12 Apr 2021.
Vancouver:
Lungaro L. Development and utility of magnetic nanoparticles production by mammalian cells. [Internet] [Doctoral dissertation]. University of Edinburgh; 2018. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/1842/31074.
Council of Science Editors:
Lungaro L. Development and utility of magnetic nanoparticles production by mammalian cells. [Doctoral Dissertation]. University of Edinburgh; 2018. Available from: http://hdl.handle.net/1842/31074
The Ohio State University
28.
Sundar Rajan, Neeraja, Rajan.
Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography.
Degree: MS, Chemical Engineering, 2018, The Ohio State University
URL: http://rave.ohiolink.edu/etdc/view?acc_num=osu1543271660561819
► Bio-separations using intrinsic magnetic properties of blood proteins is an exciting field of study. A hemoglobin molecule can exist in different oxidative states, the most…
(more)
▼ Bio-separations using intrinsic
magnetic properties of
blood proteins is an exciting
field of study. A hemoglobin molecule
can exist in different oxidative states, the most common being
oxyhemoglobin(oxy-Hb) and methemoglobin(met-Hb). Owing to the
number of unpaired electrons, while oxyhemoglobin exhibits
diamagnetism, methemoglobin exhibit paramagnetic behavior. This
contrasting
magnetic property can be used to separate the two
species using
magnetic chromatography.
Magnetic chromatography
techniques utilize
magnetic microparticles (iron microparticles or
nanoparticles) to maintain a high
magnetic gradient, which in turn
helps to separate compounds based on their
magnetic susceptibility.
To test this, in place of hemoglobin, highly
magnetic super
paramagnetic iron oxide nanoparticles (SPIONS) of diameter 5
nanometers dissolved in chloroform was placed in a column with iron
microparticles. This column was placed in the
magnetic field to
study their diffusion. It was observed that the concentration of
SPIONS in the solution was reduced within a span of thirty minutes.
The flow through collected from the column was much lighter in
color. The challenge is that due to its highly reactive nature,
hemoglobin reacts with these
magnetic microparticles and forms a
complex precipitate, making separation of the hemoglobin species
impractical. Initially, a hollow glass column was designed, and it
consisted of an equimolar mixture of hemoglobin species and
magnetic iron nanoparticles inside its annulus. This column was
placed in a Quadrupole
Magnetic System (QMS) whose
magnetic field
intensity is up to 2.5 Tesla. Due to the direct physical contact of
the iron nanoparticles with the hemoglobin complex precipitate was
formed. To overcome this, the electrospinning technique was
employed to coat the nanoparticles with polyacrylonitrile (PAN).
The nanofiber mat designed this way was placed in a
magnetic field
and an equimolar mixture of hemoglobin species was passed through
the separator. This proposal focuses on achieving higher yield of
separation by designing a suitable separator and optimizing the
nanofiber mat properties. Details of the background, experimental
techniques, simulations of the processes, results and new insights
are included in this thesis.
Advisors/Committee Members: Chalmers, Jeffrey (Advisor).
Subjects/Keywords: Chemical Engineering; Magnetic Chromatography; Quadrupole Magnetic System; SPOINS; Hemoglobin purification; Quadrupole field; Magnetic colloid
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APA (6th Edition):
Sundar Rajan, Neeraja, R. (2018). Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography. (Masters Thesis). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1543271660561819
Chicago Manual of Style (16th Edition):
Sundar Rajan, Neeraja, Rajan. “Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography.” 2018. Masters Thesis, The Ohio State University. Accessed April 12, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=osu1543271660561819.
MLA Handbook (7th Edition):
Sundar Rajan, Neeraja, Rajan. “Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography.” 2018. Web. 12 Apr 2021.
Vancouver:
Sundar Rajan, Neeraja R. Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography. [Internet] [Masters thesis]. The Ohio State University; 2018. [cited 2021 Apr 12].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1543271660561819.
Council of Science Editors:
Sundar Rajan, Neeraja R. Bio-separation of Methemoglobin and Oxyhemoglobin using
Magnetic Chromatography. [Masters Thesis]. The Ohio State University; 2018. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1543271660561819
University of Wollongong
29.
Bleasdale, Colin.
The diamagnetic Kepler problem in a semiconductor environment.
Degree: PhD, 2016, University of Wollongong
URL: 020201
Atomic
and
Molecular
Physics,
0204
CONDENSED
MATTER
PHYSICS,
010502
Integrable
Systems
(Classical
and
Quantum),
010506
Statistical
Mechanics,
Physical
Combinatorics
and
Mathematical
Aspects
of
Condensed
Matter
;
https://ro.uow.edu.au/theses/4875
► This thesis focuses on the classically chaotic motion of a Rydberg electron in an external magnetic field, known as the diamagnetic Kepler problem. This…
(more)
▼ This thesis focuses on the classically chaotic motion of a Rydberg electron in an external magnetic field, known as the diamagnetic Kepler problem. This area has been studied extensively in atomic systems since the first experimental observation of oscillations in atomic spectra in 1969 by Garton and Tomkins. In subsequent investigations, both theoretical and experimental, these oscillations were linked the closed classical orbits of Rydberg electrons excited at energies close to the ionization threshold. Under these excitation conditions, the electron goes into an sphericallysymmetric, near-zero energy radially outgoing Coulomb wave, sections of which are turned back towards the nucleus by the external magnetic field, thereby causing interference between the outgoing and returning waves resulting in the oscillations observed in the experimental atomic spectra. This can be efficiently modelled using classical mechanics by considering small sections of the electron wave as classical electrons where the length of time taken for the classical electron to traverse a closed orbit back to the nucleus is related to the experimental oscillation period. Due to its relative simplicity, hydrogen was predominately chosen to investigate this phenomenon. However, the recent detection of associated effects in the n-type hydrogenic doping centres of silicon have provided a new testing ground for these effects. In the course of the work presented here, we discuss how the semiconductor environment provides new classical effects not available in atomic systems. We investigate the effects associated with anisotropy leading to the so-called anisotropic diamagnetic Kepler problem, and also what effect the position of the oscillations in the spectrum have on the underlying classical mechanics. We then explore effects related to the addition of an external electric field in the special-case geometries of parallel and perpendicular to the external magnetic field. A new simplified theoretical framework for the general case of arbitrary external-field geometry is also developed.
Subjects/Keywords: chaos; semiconductor; doping; Kepler problem; magnetic field; electric field
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APA (6th Edition):
Bleasdale, C. (2016). The diamagnetic Kepler problem in a semiconductor environment. (Doctoral Dissertation). University of Wollongong. Retrieved from 020201 Atomic and Molecular Physics, 0204 CONDENSED MATTER PHYSICS, 010502 Integrable Systems (Classical and Quantum), 010506 Statistical Mechanics, Physical Combinatorics and Mathematical Aspects of Condensed Matter ; https://ro.uow.edu.au/theses/4875
Chicago Manual of Style (16th Edition):
Bleasdale, Colin. “The diamagnetic Kepler problem in a semiconductor environment.” 2016. Doctoral Dissertation, University of Wollongong. Accessed April 12, 2021.
020201 Atomic and Molecular Physics, 0204 CONDENSED MATTER PHYSICS, 010502 Integrable Systems (Classical and Quantum), 010506 Statistical Mechanics, Physical Combinatorics and Mathematical Aspects of Condensed Matter ; https://ro.uow.edu.au/theses/4875.
MLA Handbook (7th Edition):
Bleasdale, Colin. “The diamagnetic Kepler problem in a semiconductor environment.” 2016. Web. 12 Apr 2021.
Vancouver:
Bleasdale C. The diamagnetic Kepler problem in a semiconductor environment. [Internet] [Doctoral dissertation]. University of Wollongong; 2016. [cited 2021 Apr 12].
Available from: 020201 Atomic and Molecular Physics, 0204 CONDENSED MATTER PHYSICS, 010502 Integrable Systems (Classical and Quantum), 010506 Statistical Mechanics, Physical Combinatorics and Mathematical Aspects of Condensed Matter ; https://ro.uow.edu.au/theses/4875.
Council of Science Editors:
Bleasdale C. The diamagnetic Kepler problem in a semiconductor environment. [Doctoral Dissertation]. University of Wollongong; 2016. Available from: 020201 Atomic and Molecular Physics, 0204 CONDENSED MATTER PHYSICS, 010502 Integrable Systems (Classical and Quantum), 010506 Statistical Mechanics, Physical Combinatorics and Mathematical Aspects of Condensed Matter ; https://ro.uow.edu.au/theses/4875
University of Waterloo
30.
Lamy-Poirier, Joel.
Exact Results in Supersymmetric Gauge Theory.
Degree: 2016, University of Waterloo
URL: http://hdl.handle.net/10012/10719
► Exact results are a key component for understanding any physical theory. Unfortunately in the context of quantum field theory (QFT) they are in general impossible…
(more)
▼ Exact results are a key component for understanding any physical theory. Unfortunately in the context of quantum field theory (QFT) they are in general impossible to obtain, and we need some sort of approximations. However there exists certain non-realistic theories rich in exactly computable quantities, and from those exact quantities we can infer various theoretical implications for realistic quantum field theories. Supersymmetric gauge theories stand out among these non-realistic theories as the best compromise between the contradicting requirements of realism and exact computability.
This thesis consists of three projects, in which we explore some exact results in supersymmetric quantum field theory.
In the first project we define and describe irregular vertex operators in the H3+ Wess-Zumino-Witten model. Irregular vertex operators are a QFT-equivalent of irregular singular points in the theory of differential equations, and their study is motivated by a relation to the partition functions of some asymptotically free four-dimensional N=2 supersymmetric gauge theories. The definition is shown to be compatible with previously defined irregular vertex operators in Liouville theory through a known duality between the H3+ and Liouville theories.
In the second project we use supersymmetric localization to compute the partition function of N=2 supersymmetric gauge theories on a four-sphere in the presence of a surface defect on a two-sphere subspace, taking the form of a two-dimensional gauged linear sigma model. The result generalizes the known results for separate supersymmetric gauge theories on the separate spaces.
We obtain a partition function in the form of a standard partition function on S4, with a modified instanton partition function and an additional insertion corresponding to a shifted version of the S2 partition function.
In the third project we develop a new method for finding the ground states of fermions in the presence of BPS monopoles. We use it to find the ground states in the case of Abelian BPS monopoles in R3, which were previously unknown.
Subjects/Keywords: Physics; Quantum field theory; Conformal field theory; Supersymmetry; Magnetic monopoles
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Lamy-Poirier, J. (2016). Exact Results in Supersymmetric Gauge Theory. (Thesis). University of Waterloo. Retrieved from http://hdl.handle.net/10012/10719
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):
Lamy-Poirier, Joel. “Exact Results in Supersymmetric Gauge Theory.” 2016. Thesis, University of Waterloo. Accessed April 12, 2021.
http://hdl.handle.net/10012/10719.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lamy-Poirier, Joel. “Exact Results in Supersymmetric Gauge Theory.” 2016. Web. 12 Apr 2021.
Vancouver:
Lamy-Poirier J. Exact Results in Supersymmetric Gauge Theory. [Internet] [Thesis]. University of Waterloo; 2016. [cited 2021 Apr 12].
Available from: http://hdl.handle.net/10012/10719.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lamy-Poirier J. Exact Results in Supersymmetric Gauge Theory. [Thesis]. University of Waterloo; 2016. Available from: http://hdl.handle.net/10012/10719
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
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Open Access Theses and Dissertations
