Green's function approach for modeling of electrostatic effects in nanoscale fully depleted double‐gate silicon‐on‐insulator metal‐oxide‐semiconductor field‐effect transistors

Exact solution of two‐dimensional (2D) Poisson's equation for fully depleted double‐gate silicon‐on‐insulator metal‐oxide‐semiconductor field‐effect transistor is derived using three‐zone Green's function solution technique. Framework consists of consideration of source–drain junction curvature. 2D potential profile obtained forms the basis for estimation of threshold voltage. Temperature dependence of front surface potential distribution, back surface potential distribution and front‐gate threshold voltage are modeled using temperature sensitive parameters. Applying newly developed model, surface potential and threshold voltage sensitivities to gate oxide thickness have been comprehensively investigated. Device simulation is performed using ATLAS 2D (SILVACO, 4701 Patrick Henry Drive, Bldg. Santa Clara, CA 95054 USA) device simulator, and the results obtained are compared with the proposed 2D model. The model results are found to be in good agreement with the simulated data. Copyright © 2013 John Wiley & Sons, Ltd.     

Structural,Mechanical and Dielectric Properties of Microwave-Assisted High-Energy Ball Milling Synthesis of Hydroxyapatite

Abstract

In the present work, the effect of high-energy ball milling (HEBM) of starting precursors of hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂)/HA system on the processing temperature, morphological, mechanical, and electrical properties are highlighted. Calcination and sintering of HA system were carried out in microwave furnace. XRD study confirmed the evolution of HA phase and EDX analysis confirmed Ca/P ratio ～1.65. Grain size of HA samples, synthesized by using microwave-assisted HEBM technique was found to be in the order of 54–75?nm. Enhanced dielectric and mechanical properties were obtained in HA samples.     

Study of crystal structure,dielectric, magnetic and magnetoelecrtic properties of xCoFe2O4-(1-x)Na0.5Bi0.5TiO3 composites

Multiferroic composites of spinel ferrite and ferroelectric xCoFe₂O₄ – (1-x)Na_0.5Bi_0.5TiO₃ (with x = 0.10,0.30,0.50) were efficiently prepared by standard solid state reaction mechanism. X-ray diffractometer was used to analyze crystal structure of the prepared composites. The observed XRD patterns of the composites comprise peaks of both the phases i.e. ferrite and ferroelectric, with no sign of secondary peaks. Rietveld refinement of XRD data further confirms the coexistence of these two phases with cubic (Fd3m) and rhombohedral (R3c) symmetry corresponding to ferrite and ferroelectric phase respectively. The 3-dimensional overview of crystal structure of pure CoFe₂O₄ and Na_0.5Bi_0.5TiO₃ and of composite 0.50CoFe₂O₄?0.50Na_0.5Bi_0.5TiO₃ is generated by using refined parameters. The dielectric constant (ε´) and dielectric loss (tanδ) values were recorded as a function of frequency ranging from 100?Hz to 7?MHz and at different temperatures. Both ε´ and tanδ follow dispersion pattern at lower frequencies while show frequency independent behavior at higher frequencies. The magnetic evaluation carried by analyzing M-H hysteresis loop reveals the ferrimagnetic characteristics of these composites. The highest value of magnetic moment is 1.12μ_B observed for composite 0.50CoFe₂O₄ – 0.50Na_0.5Bi_0.5TiO_3. Magnetoelectric (ME) voltage coefficient (α) was also demonstrated to observe the interaction between ferrite and ferroelectric phases. The highest value of α (72.72μV/Oe cm) is obtained for low ferrite composition 0.10CoFe₂O₄ – 0.90Na_0.5Bi_0.5TiO₃, which suggests the dependence of magnetoelectric response on the resistivity of the composites.     

Facile synthesis of asymmetric patchy Janus Ag/Cu particles and study of their antifungal activity

Asymmetric patchy Ag/Cu Janus nanoparticles (NPs) were synthesized via a “seed-mediated” approach. This is the first report of synthesis of nanometer sized metal-based Janus NPs without using complicated methods. Selective adsorption of the surfactant onto the seed NPs leads to the formation of Janus type structure. Subsequently the reduction potential of Ag⁺/Ag⁰ and Cu²⁺/Cu⁰ systems directs the formation of the “patch”. The patchy Janus NPs show significant antifungal activity towards a potent rice pathogen thus offering the prospect of future application in crop protection.     

Visual search and target-directed action.

There have been many investigations of people's ability to search for and detect the presence of identity-defined targets in cluttered visual scenes. Such identity search tasks do not adequately represent those situations in which directed actions must be made to targets. Vision for identification and vision for action are processed in parallel, so action processing of all potential target stimuli proceeds until identification processes distinguish the target. Resulting visuomotor competition from distractors can have measurable behavioral effects on the performance of target-directed actions. Such effects are reported here for a task in which human participants reached for red targets in the presence of yellow distractors. The experiments were designed to show that increases in reaching response time could be attributed to visuomotor processing of distractors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transceiver Design and Performance Analysis of Space Time Coded Fractal Modulation

The filterbank transceiver structure for fractal modulation has been developed. It has been shown that the transceiver complexity is comparable to that of OFDM.The use of orthogonal space time block codes (OSTBC) in conjunction with Fractal Modulation (STFrM) in the presence of frequency selective fading channels has also been considered. An L scale fractal modulation and coherent demodulation effectively converts a frequency selective channel into L flat fading channels per information symbol with random scale gains. The analysis of the proposed scheme in terms of bit error rate has been performed. A diversity order of m _T m _R L can be achieved, where m _T ,m _R are the number of transmitters and receivers, respectively. This increase in diversity order in comparison with that achieved for the OFDM case is at a cost of lower spectral efficiency. However the spectral efficiency of STFrM can be improved R times by the use of multiplicity ‘R’ multiwavelets.     

Gaze cueing of attention: Visual attention, social cognition, and individual differences.

During social interactions, people's eyes convey a wealth of information about their direction of attention and their emotional and mental states. This review aims to provide a comprehensive overview of past and current research into the perception of gaze behavior and its effect on the observer. This encompasses the perception of gaze direction and its influence on perception of the other person, as well as gaze-following behavior such as joint attention, in infant, adult, and clinical populations. Particular focus is given to the gaze-cueing paradigm that has been used to investigate the mechanisms of joint attention. The contribution of this paradigm has been significant and will likely continue to advance knowledge across diverse fields within psychology and neuroscience. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the nonselectivity of "selective" seeing: Contrasts between interference and priming in selective attention.

Increasing the physical distinction between targets and distractors can eliminate Stroop interference, which has prompted claims that noninterfering distractors are not identified (e.g., C. M. Francolini and H. E. Egeth; see record 1981-09390-001). However, such claims assumed that identification always produces interference. By using Francolini and Egeth's task of counting red items in arrays of red and black items, we found that noninterfering black digits produced identity-specific negative priming comparable to that produced by interfering red digits. This suggests that interfering and noninterfering distractors are both identified and then inhibited. A similar pattern of results is observed in a task of word naming for picture-word stimuli. The contrast between interference and priming measures of the distractor processing urges reconsideration of many data previously held as evidence that distractors can be completely filtered out. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of vanadium pentoxide (and other transition metal oxides) on gas-phase combustion. IV. oxidation of isobutyraldehyde and related compounds

The slow combustion of isobutyraldehyde at 290–330° in a static system, using vessels coated with vanadium pentoxide, molybdenum oxide and bismuthphosphomolybdate, has been studied. Some results have also been obtained with isobutene oxide, isobutyric acid, propionaldehyde and n-butyraldehyde. A rapid oxidation of isobutyraldehyde occurred at 320°, the initial rate with the phosphomolybdate coating depending markedly on both the aldehyde and oxygen pressures and the overall activation energy being 23 kcal/mole. High yields of methacrolein were obtained using this coating, but much lower ones with the V₂O₅ and MoO₃ surfaces, considerable quantities of other products such as acetone being formed. Using the phosphomolybdate-coated vessel much the same analytical results were obtained with isobutene oxide (as with isobutyraldehyde) and quite a high initial yield of methacrylic acid was obtained from isobutyric acid oxidation. However, with the straight-chain aldehydes, little of the corresponding unsaturated aldehydes was formed. The oxidative dehydrogenation probably occurred on the surface and involved an allyl type intermediate. The reaction was most likely with carbonyl compounds of the structure R₁R₂CHC(R₃)CO. With isobutyraldehyde, bismuth phosphomolybdate was an active catalyst and specific towards methacrolein formation, while MoO₃ was not very active but probably quite specific and V₂O₅ was active but not very specific.     

Elimination of defective alpha-factor pheromone receptors

This report compares trafficking routes of a plasma membrane protein that was misfolded either during its synthesis or after it had reached the cell surface. A temperature-sensitive mutant form of the yeast alpha-factor pheromone receptor (ste2-3) was found to provide a model substrate for quality control of plasma membrane proteins. We show for the first time that a misfolded membrane protein is recognized at the cell surface and rapidly removed. When the ste2-3 mutant cells were cultured continuously at 34 degrees C, the mutant receptor protein (Ste2-3p) failed to accumulate at the plasma membrane and was degraded with a half-life of 4 min, compared with a half-life of 33 min for wild-type receptor protein (Ste2p). Degradation of both Ste2-3p and Ste2p required the vacuolar proteolytic activities controlled by the PEP4 gene. At 34 degrees C, Ste2-3p comigrated with glycosylated Ste2p on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that Ste2-3p enters the secretory pathway. Degradation of Ste2-3p did not require delivery to the plasma membrane as the sec1 mutation failed to block rapid turnover. Truncation of the C-terminal cytoplasmic domain of the mutant receptors did not permit accumulation at the plasma membrane; thus, the endocytic signals contained in this domain are unnecessary for intracellular retention. In the pep4 mutant, Ste2-3p accumulated as series of high-molecular-weight species, suggesting a potential role for ubiquitin in the elimination process. When ste2-3 mutant cells were cultured continuously at 22 degrees C, Ste2-3p accumulated in the plasma membrane. When the 22 degrees C culture was shifted to 34 degrees C, Ste2-3p was removed from the plasma membrane and degraded by a PEP4-dependent mechanism with a 24-min half-life; the wild-type Ste2p displayed a 72-min half-life. Thus, structural defects in Ste2-3p synthesized at 34 degrees C are recognized in transit to the plasma membrane, leading to rapid degradation, and Ste2-3p that is preassembled at the plasma membrane is also removed and degraded following a shift to 34 degrees C.