In the report the results of phase formation and magnetoplastic effect (МPE) researches in five alloys on the Al-basis with additives Mg, Li, Zn, Cu, Si, Fe and Mn, aged in a constant magnetic field (CMF) and pulse magnetic field (PMF), are presented. Preliminary the samples subjected to annealing in the furnace at the air atmosphere, then quenched in water at a room temperature. Further the quenched samples are artificial aged in vacuum in CMF and PMF and without it. Microstructure, MPE, phase content and parameters of thin structure of a residual α-matrix of samples have been investigated by methods of metallography, microhardness, X-ray structure and phase analysis.

Layer-by-layer (LBL) polyelectrolyte capsules can be modified to incorporate stimuli such as superparamagnetic nanoparticles which respond to a magnetic field only when it is turned on. Thus, they can act as a switch to load or unload their drug cargo on demand. Specifically, magnetite is incorporated into bilayer capsules made of alternating poly(allylamine hydrochloride) (PAH) and poly(sodium-p-styrenesulfonate) (PSS) which surrounds calcium carbonate core. The core is then dissolved using ethylenediaminetetraacetic acid (EDTA). These capsules are loaded with at FITC-BSA conjugate and examined with fluorescence to show the unloading of the FITC-BSA from capsules as it brightens the entire field of view of the microscope. The results suggest that we can next load and unload an anticancer drug such as doxorubicin using the combination of microcapsule and alternating magnetic field (AMF) to treat the cancer cells. Preliminary data interprets that the low frequency AMF we use has little to no adverse effect cells viability. This coincides with the general thought that low frequency AMF signals are not harmful to humans. Therefore, as an alternative to hyperthermia methods which use heat, it may be possible to deliver the anticancer drugs specifically to the cells when and where it is needed.

Master of Science / We are in an ever-increasing demand for computing power to sustain our technological advancements. A significant driving factor of our progress is the size and speed of memory we possess. Modern computer architectures use DDR4-based DRAM (Dynamic Random Access Memory) to hold all the immediate information for processing needs. Each bit in a DRAM memory module is implemented with a tiny capacitor and a transistor. Since the capacitors are prone to charge leakage, each bit must be frequently rewritten with its old value. A dedicated memory controller handles the periodic refreshes. If the cells aren't refreshed, the bits lose their charge and lose the information stored by flipping to either 0 or 1 (depending upon the design). Due to manufacturing variations, every tiny capacitor fabricated will have different physical characteristics. Charge leakage depends upon capacitance and other such physical properties. Hence, no two DRAM modules can have the same properties and decay pattern and cannot be reproduced again accurately. This DRAM attribute can be considered a source of 'Physically Unclonable Functions' and is sought after in the Cryptography domain. This thesis aims to characterize the decay patterns of commercial DDR4 DRAM modules. I implemented a custom System On Chip on AMD/Xilinx's ZCU104 FPGA platform to interface different DDR4 modules with a primitive memory controller (without refreshes). Additionally, I introduced electric and magnetic fields close to the DRAM module to investigate their effects on the decay characteristics.

Polarimetric CCD images of HII regions were obtained using a rotating polarizer device designed, built, and used in conjunction with the Spectral Line Imaging Camera (SLIC) at Virginia Tech's Martin Observatory in Giles County, Virginia. The SLIC uses a narrow bandpass interference filter coupled with a 58 mm camera lens and cryogenically cooled CCD camera to image diffuse, extended H-alpha emission over a 10° angular extent. A rotating polarizer device was placed in front of the H-alpha filter with images recorded at every 45° with respect to a fiducial setting. Stoke's parameters and were obtained and polarization maps of selected HII regions were created. Maps of the Monoceros supernova remnant and the Rosette Nebula (NGC 2237-9) were made in an attempt to detect polarization by selective extinction in H light. While this was not detected, polarization by scattering in a dust shell around the Rosette Nebula (NGC 2237-9) was observed. Scattered continuum light from the central star cluster NGC 2244 in the H-alpha bandpass was ruled out. Using Celnik's (1985) map of extinction across the Rosette Nebula at the H wavelength, coupled with Serkowski's empirical relationship between maximum polarization and color excess, it was shown that the maximum degree of polarization seen in the Rosette Nebula should be no more than 3% to 4%. The polarization observed in this project reaches values as high as 10%. It was found that a correlation exists between the H-alpha intensity and infrared emission by dust grains in all four IRAS waveband images in the suspected scattering region of the Rosette Nebula. A radial comparison between [SII] images and H-alpha images in the region of high polarization showed that the H-alpha intensity in that region is dominated by scattered H-alpha light from the Rosette Nebula. A single scattering model was constructed in an effort to predict the observed polarization. The model used parameters based on 21 cm observations by Kuchar and Bania (1993) of the HI shell which surrounds the HII region of the Rosette Nebula. The single scattering model can not accurately predict the degree of polarization. It was concluded that a multiple scattering model is required. A spatial comparison of the 12 m emission with the degree of polarization strongly suggested that multiple scattering is important in describing the observed radial behavior of polarization. Polarization images of regions in Cygnus were obtained. A polarization map of the North America Nebula (NGC 7000) and surroundings reveals a large amount of polarization. The map reveals that scattering of H-alpha light from the North America Nebula is the most likely cause of polarization in these images. From the analysis in this thesis, I conclude that in the northwest quadrant, at radial distances greater than 40 from the center of the Rosette Nebula, the observed H-alpha intensity is due to scattered H light from the nebula itself. This implies that, in H-alpha , the Rosette Nebula appears slightly larger than it actually is. With evidence of polarization by scattered H supported by the polarization map of the North America Nebula (NGC 7000), it is concluded that other HII regions may very well appear larger in H-alpha than they actually are. Thus, scattered H-alpha light may account for a small part of the more extended warm ionized medium as well. / Ph. D.

Wireless power transfer (WPT) with loosely coupled coils is a promising solution to deliver power to a battery in a variety of applications. Due to its convenience, wireless power transfer technology has become popular in consumer electronics. Thus far, the majority of the coupled coils in these systems are planar structure, and the magnetic field induced by the transmitter coil is in one direction, meaning that the energy power transfer capability degrades greatly when there is some angle misalignment between the coupled coils. To improve the charging flexibility, a three–dimensional (3D) coils structure is proposed to transfer energy in different directions. With appropriate modulation current flowing through each transmitter coil, the magnetic field rotates in different directions and covers all the directions in 3D space. With omnidirectional magnetic field, the charging platform can provide energy transfer in any direction; therefore, the angle alignment between the transmitter coil and receiver coil is no longer needed. Compensation networks are normally used to improve the power transfer capability of a WPT system with loosely coupled coils. The resonant circuits, formed by the loosely coupled coils and external compensation inductors or capacitors, are crucial in the converter design. In WPT system, the coupling coefficient between the transmitting coil and the receiving coil is subject to the receiver's positioning. The variable coupling condition is a big challenge to the resonant topology selection. The detailed requirements of the resonant converter in an omnidirectional WPT system are identified as follows: 1). coupling independent resonant frequency; 2). load independent output voltage; 3). load independent transmitter coil current; 4). maximum efficiency power transfer; 5). soft switching of active devices. A LCCL-LC resonant converter is derived to satisfy all of the five requirements. In consumer electronics applications, Megahertz (MHz) WPT systems are used to improve the charging spatial freedom. 6.78 MHz is selected as the system operation in AirFuel standard, a wireless charging standard for commercial electronics. The zero voltage switching (ZVS) operation of the switching devices is essential in reducing the switching loss and the switching related electromagnetic interference (EMI) issue in a MHz system; therefore, a comprehensive evaluation of ZVS condition in an omnidirectional WPT system is performed. And a design methodology of the LCCL-LC converter to achieve ZVS operation is proposed. The big hurdle of the WPT technology is the safety issue related to human exposure of electromagnetic fields (EMF). A double layer shield structure, including a magnetic layer and a conductive layer, is proposed in a three dimensional charging setup to reduce the stray magnetic field level. A parametric analysis of the double shield structure is conducted to improve the attenuation capability of the shielding structure. In an omnidirectional WPT system, the energy can be transferred in any direction; however the receiving devices has its preferred field direction based on its positioning and orientation. To focus power transfer towards targeted loads, a smart detection algorithm for identifying the positioning and orientation of receiver devices based on the input power information is presented. The system efficiency is further improved by a maximum efficiency point tracking function. A novel power flow control with a load combination strategy to charge multiple loads simultaneously is explained. The charging speed of the omnidirectional WPT system is greatly improved with proposed power flow control. / Doctor of Philosophy / Wireless power transfer (WPT) is a promising solution to deliver power to a battery in a variety of applications. Due to its convenience, wireless power transfer technology with loosely coupled coils has become popular in consumer electronics. In such system, the receiving coil embedded in the receiving device picks up magnetic field induced by the transmitter coil; therefore, energy is transferred through the magnetic field and contactless charging is achieved. Thus far, the majority of the coupled coils in these systems are planar structure, and the magnetic field induced by the transmitter coil is in one direction, meaning that the energy power transfer capability degrades greatly when there is some angle misalignment between the coupled coils. To improve the charging flexibility, a three–dimensional (3D) coils structure is proposed to transfer energy in different directions, also known as in omnidirectional manner. With omnidirectional magnetic field, the charging platform can provide energy transfer in any direction; therefore, the angle alignment between the transmitter coil and receiver coil is no longer needed. In a WPT system with loosely coupled coils, the energy transfer capability suffers from weak coupling condition. To improve the power transfer capability, the electrical resonance concept between the inductor and capacitor at the power transfer frequency is adopted. A novel compensation network is proposed to form a resonant tank with the loosely coupled coils and maximize the power transfer at the operating frequency. As for the WPT system with loosely coupled coils, the energy transfer capability is also proportional to the operating frequency. Therefore, Megahertz (MHz) WPT systems are used to improve the charging spatial freedom. 6.78 MHz is selected as the system operation in AirFuel standard, a wireless charging standard for commercial electronics. The zero voltage switching (ZVS) operation of the switching devices is essential in reducing the switching loss and the switching related electromagnetic interference (EMI) issue in a MHz system; therefore, a comprehensive evaluation of ZVS condition in an omnidirectional WPT system is performed. The big hurdle of the WPT technology is the safety concern related to human exposure of electromagnetic fields (EMF). Therefore, a double layer shield structure is first applied in a three dimensional charging setup to confine the electromagnetic fields effectively. The stray field level in our charging platform is well below the safety level required by the regulation agent. Although the energy can be transferred in an omnidirectional manner in the proposed charging platform, the energy should be directed to the target loads to avoid unnecessary energy waste. Therefore, a smart detection method is proposed to detect the receiver coil's orientation and focus the energy transfer to certain direction preferred by the receiver in the setup. The energy beaming strategy greatly improves the charging speed of the charging setup.

Experimental results and simulations of imploding fusion concepts have identified the Rayleigh-Taylor (RT) instability as one of the largest inhibitors to achieving fusion. Understanding the origin and development of the RT instability will allow for the development of mitigating measures to dampen the instability growth, thus improving the chance that fusion concepts such as inertial confinement fusion (ICF) are successful. A study of 1D and 2D simulations are presented for investigating RT instability growth in deceleration stage of imploding geometries. Two cases of laser-driven implosion geometry, Cartesian and cylindrical, are used to study late stage deceleration-phase RT instability development on the interior surface of imploding targets. FLASH's hydrodynamic (HD) and magnetohydrodynamic (MHD) modeling capabilities are used for different laser and target parameters in order to study the RT instability and the impact of externally applied magnetic fields on their evolution. Several simulation regimes have been identified that provide novel insight into the impact that a seeded magnetic field can have on RT instability growth and the conditions under which magnetic field stabilization of the RT instability is observable. Finally, future work and recommendations are made. / Master of Science / The direction for the future of renewable energy is uncertain at this time; however, it is known that the future of human energy consumption must be green in order to be sustainable. Fusion energy presents an opportunity for an unlimited clean renewable energy source that has yet to be realized. Fusion is achieved only by overcoming the earthly limitations presented by trying to replicate conditions at the interior of stellar structures. The pressures, temperature, and densities seen in the interior of stars are not easily reproduced, and thus human technology must be developed to reach these difficult stellar conditions in order to harvest fusion energy. There are two main branches of developmental technology geared towards achieving the difficult conditions controlled nuclear fusion presents, magnetic confinement fusion (MCF) and inertial confinement fusion (ICF)[17]. Yet in both approaches barriers exist which have thwarted the efforts toward reaching fusion ignition which must be addressed through scientific discovery. Successfully reaching ignition is only the first step in the ultimate pursuit of a self sustaining fusion reactor. This work will focus on the experimental ICF configuration, and on one such inhibitor toward achieving ignition, the Rayleigh-Taylor (RT) instability. The RT instability develops on the surfaces of the fusion fuel capsules, targets, and causes nonuniform compression of the target. This nonuniform compression of the target leads to lower pressures and densities through the material mixing of fusion fuel and the capsule shell, which ultimately leads to challenges with reaching fusion ignition. The work presented here was performed utilizing the University of Chicago's FLASH code, which is a state-of-the-art open source radiation magneto-hydrodynamic (MHD) code used for plasma and astrophysics computational modeling [11]. Simulations of the RT instability are performed using FLASH in planar and cylindrical geometries to explore fundamental Rayleigh-Taylor instability evolution for these two different geometries. These geometries provide easier access for experimental diagnostics to probe RT dynamics. Additionally, the impact of externally applied magnetic fields are explored in an effort to examine if and how the detrimental instability can be controlled.

京都大学 / 新制・課程博士 / 博士(人間・環境学) / 甲第25367号 / 人博第1109号 / 新制||人||259(附属図書館) / 京都大学大学院人間・環境学研究科共生人間学専攻 / (主査)教授 日置 尋久, 教授 立木 秀樹, 准教授 DE BRECHTMatthew, 教授 下田 宏, 教授 小山田 耕二 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DGAM

In the 50+ years since the discovery of magnetic compass orientation by migratory songbirds, evidence for the use of magnetic cues has been obtained for a range of taxonomic groups, including several classes of vertebrate and invertebrate taxa. Surprisingly, however, the biophysical mechanisms and biological substrate that underlie magnetic sensing are still not fully understood. Moreover, while use of magnetic cues for compass orientation is intuitive, the functional significance of other forms of behavioral responses mediated by magnetic cues, such as spontaneous magnetic alignment, is less clear. The following research was carried out to investigate the mechanisms underlying magnetic orientation in vertebrates and invertebrates. This involved the modification of existing experimental systems to characterize responses to magnetic cues in laboratory animals (flies, mice) and the development of novel techniques for studying the role of magnetic cues in the spatial behavior of free-living animals (red foxes). Chapter II examines magnetic orientation in wild-type Drosophila melanogaster larvae. We show that three strains of larvae reared under non-directional ultraviolet (UV) light exhibit quadramodal spontaneous orientation along the anti-cardinal compass directions (i.e. northeast, southeast, southwest, northwest) when tested in a radially symmetrical environment under UV light. Double-blind experiments cancelling the horizontal component of the magnetic field confirmed that the response is dependent on magnetic cues rather non-magnetic features of the test environment. Furthermore, we argue that the larval quadramodal pattern of response is consistent with properties of magnetic compass orientation observed in previous studies of adult Drosophila and laboratory mice, both of which have been proposed to be mediated by a light-dependent magnetic compass mechanism. Chapter III explores the use of novel biologging techniques to collect behavioral and spatial data from free-roaming mammals. Specifically, a previous observational study of free- roaming red foxes found a 4-fold increase in the success of predatory 'mousing' attacks when foxes were facing ~north-northeast, consistent with magnetic alignment responses reported for a range of terrestrial animals. The authors propose that the magnetic field may be used to increase accuracy of mousing attacks. Using tri-axial accelerometer and magnetometer bio-loggers fitted to semi-domesticated red foxes, we created ']magnetic ethograms' from behavioral and magnetic machine learning algorithms 'trained'] to identify three discrete behaviors (i.e. foraging, trotting, and mousing-like jumps) from raw accelerometer signatures and to classify the magnetic headings of mousing-like jumps into 45° sectors from raw magnetometer data. The classifier's ability to accurately identify behaviors from a separate fox not used to train the algorithm suggests that these techniques can be used in future experiments to obtain reliable magnetic ethograms for free-roaming foxes. We also developed the first radio-frequency emitting collar that broadcasts in the low MHz frequency range shown to disrupt magnetic compass responses in a host of animals. The radio-frequency collars coupled with biologgers will provide a powerful tool to characterize magnetic alignment responses in predatory red foxes and can be adapted for use in studies of magnetic alignment and magnetic compass orientation in other free-roaming mammals. Chapter 3 discusses findings from a magnetic nest building assay involving male labratory mice. Mice trained to position nests in one of four directions relative to the magnetic field exhibited both learned magnetic compass responses and fixed magnetic nest positioning orientation consistent with northeast-southwest spontaneous magnetic alignment behavior previously reported for wild mice and bank voles. This is the first mammalian assay in which both learned magnetic compass orientation and spontaneous magnetic alignment were exhibited in the same species, and suggests that the use of magnetic cues in rodents may be more flexible that previously realized. / Ph. D. / A variety of animals have been shown to use the Earth’s magnetic field to help guide diverse spatial behaviors, however, the underlying sensory mechanisms mediating this sense remain elusive. Evidence for two distinct sensory mechanisms has come from behavioral studies involving a wide range of organisms, including migratory birds, newts, mole rats, mice, and several classes of invertebrates. The following research was carried out to determine the underlying sensory mechanisms mediating magnetic sensing in larval fruit flies. Properties consistent with a light-dependent, photoreceptor-based mechanism were found to underlie innate magnetic alignment behavior in larval flies, similar to the proposed compass mechanism thought to mediate compass responses in migratory birds and newts. A reanalysis of two previous studies of learned magnetic compass responses in adult fruit flies and laboratory mice show similar behaviors when compared to that of larval flies, suggesting a common underlying light-dependent magnetic mechanism across these groups. Furthermore, we provide evidence for learned magnetic compass responses in laboratory mice, where the orientation of individuals appears to be dependent on properties of the local environment (e.g. electromagnetic, temperature, humidity) in training and testing. These data suggest that the use of magnetic cues in mammals is context-dependent and more flexible than previously recognized. We have also developed new technologies for studies of magnetic orientation in free-roaming animals. Specifically, bio-logging devices containing triaxial accelerometer and magnetometer sensors where used to create ‘magnetic ethograms’, where the behavior and magnetic alignment of an animal can be reliably and accurately extracted from raw sensor data. We also discuss possible field experiments that can be performed to provide a specific test of the underlying sensory mechanism mediating magnetic behavior in free-roaming animals. This work will likely be of interest to a broad range of disciplines including sensory ecology, ethology, quantum chemistry, biophysics, wildlife management, and conservation.

Yes / The gadolinium-doped iron oxide nanoparticles (GdIONP) with greater specific power adsorption rate (SAR) than Fe3O4 was developed and its potential application in tumour therapy and particle tracking were demonstrated in transgenic adenocarcinoma of the mouse prostate C1 (TRAMP-C1) tumours. The GdIONPs accumulated in tumour region during the treatment could be clearly tracked and quantified by T2-weighted MR imaging. The therapeutic effects of GdIONP-mediated hyperthermia alone or in combination with radiotherapy (RT) were also evaluated. A significant increase in the tumour growth time was observed following the treatment of thermotherapy (TT) only group (2.5 days), radiation therapy only group (4.5 days), and the combined radio-thermotherapy group (10 days). Immunohistochemical staining revealed a reduced hypoxia region with vascular disruption and extensive tumour necrosis following the combined radio-thermotherapy. These results indicate that GdIONP-mediated hyperthermia can improve the efficacy of RT by its dual functions in high temperature (temperature greater than 45 °C)-mediated thermal ablation and mild-temperature hyperthermia (MTH) (temperature between 39 and 42 °C)-mediated reoxygenation.

A Finite Element model was built to analyze and examine a 2-D axisymmetric MR damper. This model has been validated with the experimental data. The results obtained in this thesis will help designers to create more efficient and reliable MR dampers. We can create some design analysis to change the shape of the piston in the damper or other parameters in the model. The main benefit of this research is to show a 2-D MR damper and generate the magnetic flux density along the MR Fluid gap. We can detect saturation by looking at the nodal solution for the magnetic flux density. Increasing the current in the model, results in an increase in magnetic induction. We studied four different configurations of an MR damper piston in order to determine how changing the shape of the piston affects the maximum force that the damper can provide. In designing MR dampers, the designer always faces the challenge of providing the largest forces in the most compact and efficient envelope. Therefore, it is important to identify the configuration that gives more force in less space. In chapter 4, shows the magnetic flux density contour before and after reaching the rheological saturation. By increasing the current, the color spectrum of the magnetic flux density will shift from the MR fluid gap to the piston centerline. In chapter 5, we provided a reasonably good amount of force in model 4 at 1.4 Amps, but it reaches saturation before the other models. For cases with power constraint or heat build up limitations, this model could work the best among the four designs that we considered. For cases where higher electrical currents can be tolerated, model 3 would be the most advantageous design, since it provides the largest force among the four models. / Master of Science