Double aperture double-gate vertical high-electron-mobility transistor

In this paper, we propose a double aperture double-gate AlGaN/GaN vertical high-electron-mobility transistor (HEMT) to improve the device characteristics, such as the current and the ON resistance (\(\hbox {\textit{R}}_{\mathrm{ON}}\)). The proposed vertical HEMT results are compared to the conventional single aperture single-gate vertical HEMT of equal dimensions, and increased drain current and lower \(\hbox {\textit{R}}_{\mathrm{ON}}\) are shown. A comprehensive simulation study has also been carried out for the proposed device, to analyse the impact of thickness and doping concentration of aperture, drift region, and current blocking layer. In addition, the effect of different materials in current blocking layer on device characteristics is also studied. The obtained results and their effect on device characteristics have been thoroughly analysed and explained accordingly.     

Clique Number vs. Chromatic Number in Wireless Interference Graphs: Simulation Results

Interference due to transmissions by adjacent nodes in a multi-hop wireless network can be modeled using a unit disc graph (UDG). We investigate the reliability associated with using the clique number instead of the chromatic number of the UDG while computing the interference. In our extensive simulations with UDGs of random networks, we observed that the clique number and the chromatic number values were typically very close to one another and the maximum deviation was much less than the theoretical bounds. This implies very high reliability in the proposed approximation.     

Design of Cryogenic SiGe Low-Noise Amplifiers

This paper describes a method for designing cryogenic silicon-germanium (SiGe) transistor low-noise amplifiers and reports record microwave noise temperature, i.e., 2 K, measured at the module connector interface with a 50-Omega generator. A theory for the relevant noise sources in the transistor is derived from first principles to give the minimum possible noise temperature and optimum generator impedance in terms of dc measured current gain and transconductance. These measured dc quantities are then reported for an IBM SiGe BiCMOS-8HP transistor at temperatures from 295 to 15 K. The measured and modeled noise and gain for both a single-and two-transistor cascode amplifier in the 0.2-3-GHz range are then presented. The noise model is then combined with the transistor equivalent-circuit elements in a circuit simulator and the noise in the frequency range up to 20 GHz is compared with that of a typical InP HEMT.     

Node-Level Energy Management for Sensor Networks in the Presence of Multiple Applications

Wireless Networks - Energy related research in wireless ad hoc sensor networks (WASNs) is focusing on energy saving techniques in the application-, protocol-, service-, or hardware-level. Little...     

A novel magnetic random access memory design using square ring elements for the hard layer

The behavior of narrow permalloy square rings under the influence of a magnetic field was studied using magnetic force microscopy (MFM). Two stable states of opposite polarity at remanence and simple switching were observed. We propose a design for the hard layer of magnetic random access memory (MRAM) that uses these states in square rings for data storage.     

The status and distance of cone biopsy margins as a predictor of excision adequacy for endocervical adenocarcinoma in situ

The purpose of this study was to begin to examine the influence of inhaled NO on O2 toxicity. The survival of Sprague-Dawley rats exposed to >95% O2, >95% O2 + 10 ppm NO, >95% O2 + 100 ppm NO, and >95% O2 + 3 ppm NO2 was determined. Survival at 120 h was 2/24 in >95% O2, 2/12 in >95% O2 + 10 ppm NO, and 1/12 in >95% O2 + 3 ppm NO2. Survival at 120 h was 21/30 in >95% O2 + 100 ppm NO (p < 0.01 compared with >95% O2). Three additional groups of rats were exposed for 60 h to: 21% O2, >95% O2, or >95% O2 + 100 ppm NO. The lungs were then assayed for total protein, reduced (GSH) and oxidized glutathione (GSSG), and 4-hydroxy-2(E)-nonenal. Both of the high O2 groups had significantly (p < 0.05) lower GSH/mg protein and GSH/GSSG ratios compared with the 21% O2 group. The >95% O2 group had a higher 4-hydroxy-2(E)-nonenal/mg of protein than either the 21% O2 group (p < 0.05), or the >95% O2 + 100 ppm NO group (p < 0.05 compared with >95% O2, not different from the 21% O2 group). Additional groups of rats were exposed to either 21% O2, >95% O2, or >95% O2 + 100 ppm NO for 0, 24, 48, and 60 h. The lungs were examined for neutrophil accumulation, which was increased at 60 h in the two groups exposed to >95% O2, but adding NO had no effect. Thus, the overall result was that 100 ppm inhaled NO improved the survival of rats in high O2.     

Singular value decomposition for dynamic system design sensitivity analysis

A computer-based method for automatic generation and efficient numerical solution of mixed differential-algebraic equations for dynamic and design sensitivity analysis of dynamic systems is developed. The equations are written in terms of a maximal set of Cartesian coordinates to facilitate general formulation of kinematic and design constraints and forcing functions. Singular value decomposition of the system Jacobian matrix generates a set of composite generalized coordinates that are best suited to represent the system. The coordinates naturally partition into optimal independent and dependent sets, and integration of only the independent coordinates generates all of the system information. An adjoint variable method is used to compute design sensitivities of dynamic performance measures of the system. A general-purpose computer program incorporating these capabilities has been developed. A numerical example is presented to illustrate accuracy and properties of the method.     

Lactic acid in human aqueous humour

IQs of rapists were compared to IQs of nonrapist prisoners convicted of violent crimes and nonrapist prisoners convicted of nonviolent crimes. Subjects were 136 male convicted felons in the Kentucky State Penitentiary. Determination of violent vs. nonviolent crimes other than rape was made upon consultation with a Kentucky Commonwealth Attorney. The results revealed significantly lower IQs for rapists compared to nonrapists convicted of violent crimes and compared to heterogeneous nonrapist convicts. The present research supports the findings of Karacan and co-workers, indicating a general tendency for rapists to have lower IQs than other convicted prisoners.     

Heparan/chondroitin/dermatan sulfate primer 2-(6-hydroxynaphthyl)-O-beta-D-xylopyranoside preferentially inhibits growth of transformed cells

Melanocortins are proopiomelanocortin-derived peptides that include adrenocorticotropic hormone [ACTH (1-39)], alpha-melanocyte-stimulating hormone [alpha-MSH (1-13)], and related amino acid sequences. Melanocortin peptides have potent antiinflammatory/anticytokine activity. Because cytokines such as interleukin 1 (IL-1) and tumor necrosis factor (TNF) can be detrimental in HIV-infected patients, we investigated the effects of melanocortins on production of IL-1 and TNF alpha in the blood of HIV patients. Cytokine production was measured in whole blood samples stimulated with LPS in the presence or absence of alpha-MSH (1-13), alpha-MSH (11-13), ACTH (1-24), or ACTH (1-39). Melanocortins reduced production of both cytokines in a concentration-dependent fashion. In separate experiments on normal peripheral blood mononuclear cells (PBMC), alpha-MSH (1-13) inhibited production of IL-1 beta and TNF alpha induced by HIV envelope glycoprotein gp 120. These results suggest that stimulation of melanocortin receptors in inflammatory cells could be a novel way to reduce production of cytokines that promote HIV replication.     

Coupled B-snake grids and constrained thin-plate splines foranalysis of 2-D tissue deformations from tagged MRI

Magnetic resonance imaging (MRI) is unique in its ability to noninvasively and selectively alter tissue magnetization and create tagged patterns within a deforming body such as the heart muscle. The resulting patterns define a time-varying curvilinear coordinate system on the tissue, which the authors track with coupled B-snake grids. B-spline bases provide local control of shape, compact representation, and parametric continuity. Efficient spline warps are proposed which warp an area in the plane such that two embedded snake grids obtained from two tagged frames are brought into registration, interpolating a dense displacement vector field. The reconstructed vector field adheres to the known displacement information at the intersections, forces corresponding snakes to be warped into one another, and for all other points in the plane, where no information is available, a C¹ continuous vector field is interpolated. The implementation proposed in this paper improves on the authors' previous variational-based implementation and generalizes warp methods to include biologically relevant contiguous open curves, in addition to standard landmark points. The methods are validated with a cardiac motion simulator, in addition to in-vivo tagging data sets