740 research outputs found
In-Silico Hyperthermia Performance of a Near-Field Patch Antenna at Various Positions on a Human Body Model
A compact patch applicator designed to enhance targeted energy coupling at 434 MHz is a key enabler for sensitizing temperature increments in body regions containing superficial tumours. A detailed FDTD body model is used to explore simulated RF coupling and temperature increments for typical clinical conditions. The antenna impedance matching, specific absorption rate and thermal distribution parameters are evaluated to identify applied performance outcomes. The analysis reveals physiological-RF coupling patterns for an optimised closely-coupled single element applicator
Demonstration of electron focusing using electronic lenses in low-dimensional system.
We report an all-electric integrable electron focusing lens in n-type GaAs. It is shown that a pronounced focusing peak takes place when the focal point aligns with an on-chip detector. The intensity and full width half maximum (FWHM) of the focusing peak are associated with the collimation of injected electrons. To demonstrate the reported focusing lens can be a useful tool, we investigate the characteristic of an asymmetrically gate biased quantum point contact with the assistance of a focusing lens. A correlation between the occurrence of conductance anomaly in low conductance regime and increase in FWHM of focusing peak is observed. The correlation is likely due to the electron-electron interaction. The reported electron focusing lens is essential for a more advanced electron optics device
Interaction of RF-hyperthermia Applicator with High Fidelity Human Body Model
A compact patch antenna working at the 434 MHz ISM frequency band is proposed as an RF-Hyperthermia applicator. The electromagnetic interaction in terms of S11, SAR and E-Field distribution of the antenna with a High Fidelity human body model is investigated. This analysis provides useful information for engineers and clinical staff to develop more efficient and smaller antennas for medical applications, in particular for RF-Hyperthermia cancer therapy, where the size of the antenna determines tumor accessibility
Nonequilibrium phenomena in bilayer electron systems
In the present Letter, we have used magnetocapacitance and magnetoresistance measurements to investigate nonequilibrium phenomena in a bilayer electron system based on GaAs/AlGaAs heterostructures. The magnetic field ramping drives the bilayer electron system out of equilibrium, leading to magnetoresistance hysteresis and spikes. Unlike magnetoresistance, magnetocapacitance results intriguingly show hysteresis even when both layers are in the quantum Hall state. The hysteresis is accompanied by interlayer charge transfer, but the disequilibrium is not limited to interlayer imbalance. Results show that the edge-bulk imbalance can be the initial ground for the appearance of hysteresis. In addition, the nonequilibrium states are observed in which the total, rather than individual, layer densities determine the magnetic field and gate voltage dependencies
Educational Usage of Mobile Devices: Differences Between Postgraduate and Undergraduate Students
The rapid increase of smartphone usage in recent years has provided students the opportunity to participate in mobile learning (m-learning) anywhere, anytime. Academic institutions are also following this trend to launch many m-learning services. This article investigates the differences of the user needs between undergraduate (UG) and postgraduate (PG) students though an online survey with 140 Library Information Systems (LIS) subjects in a Japanese university in order to provide solid foundations for future m-learning studies. We find that UG and PG students do not show significant differences in adopting m-learning by smartphones despite the fact that they have different learning patterns. The m-learning frequencies of smartphones generally range from weekly to monthly, where using search engines is the most frequent, and reading academic resources is the least frequent. They tend to use these services for handling their daily routines (such as search engine, social networks) rather than their academic activities (such as using online databases to search for academic materials). Further, the results also show that content displaying issues (e.g., small display screen, text unable to enlarge) are barriers for most subjects in using these m-learning services
The Grounds and Extent of Legal Responsibility
To question that is the title of this symposium, What Do Compensatory Damages Compensate?, requires consideration of the basic grounds and purposes of legal responsibility. The question is usefully brought into sharper focus by the specific questions and puzzles posed to the contributors to stimulate thought and discussion
Fano resonance in a cavity-reflector hybrid system.
© 2017 authors. Published by the American Physical Society.We present the results of transport measurements in a hybrid system consisting of an arch-shaped quantum point contact (QPC) and a reflector; together, they form an electronic cavity in between them. On tuning the arch-QPC and the reflector, an asymmetric resonance peak in resistance is observed at the one-dimension to two-dimension transition. Moreover, a dip in resistance near the pinch-off of the QPC is found to be strongly dependent on the reflector voltage. These two structures fit very well with the Fano line shape. The Fano resonance was found to get weakened on applying a transverse magnetic field, and smeared out at 100 mT. In addition, the Fano-like shape exhibited a strong temperature dependence and gradually smeared out when the temperature was increased from 1.5 to 20 K. The results might be useful in realizing devices for quantum information processing
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