Impact of Mole Fractions due to Work Function Variability (WFV) of Metal Gate on Electrical Parameters in Strained SOI-FinFET

In the recent sub-20 nm technology node, the process variability issues have become a major problem for scaling of MOS devices. We present a design for a strained Si/SiGe FinFET on an insulator using a 3D TCAD simulator. The impact of metal gate work function variability (WFV) on electrical parameters is studied. Such impact of WFV for different mole fractions (x) of the SiGe layer in a strained SOI-FinFET with varying grain size is presented. The results show that as the mole fraction is increased, the variability in threshold voltage (σVT) and off current (σIoff) is decreased; while, the variability of on-current (σIon) is increased. A notable observation is the distribution of electrical parameters approaches a normal distribution for smaller grain sizes.     

<Emphasis Type="Bold">Analysis of Spatio-temporal Characteristics and Regional Frequency of Droughts in the Southern Peninsula of India</Emphasis>

A detailed regional drought study is carried out in the southern peninsula of India to characterize the spatio-temporal nature of droughts and to predict the drought magnitudes for various probabilities in the homogeneous drought regions. The method of several random initializations of the cluster centres of the K-means algorithm is suggested for the identification of the initial regions in the context of drought regionalization, which is shown to perform better than the initialization from the Ward’s algorithm and the Ward’s algorithm itself. The peninsula is classified into seven spatially well-separated homogeneous drought regions. The robust L-moment framework is used for the regional frequency analysis of drought magnitudes computed using the standardized precipitation index. The Pearson type III is found to be appropriate for regional drought frequency analysis in six of the regions, while the robust Wakeby distribution is suggested for one region. Low magnitude droughts are frequent and dominant in the northern part of west coast, the north-eastern coast and its adjoining inland region, while high magnitude droughts are less in number and are experienced in semi-arid central part, southern part of western coast, south-eastern part and north-western inland region. The spatial maps of drought magnitudes indicate that at higher return periods (100 and 200 years) the south-eastern part of the peninsula is likely to encounter high magnitude droughts, while the central region is likely to experience the same at lower return periods (10 and 50 years). Hence these regions need to be given special importance in the drought mitigation planning activities.     

A Comprehensive Survey of Emergency Communication Network and Management

Wireless Personal Communications - The performance of wireless communication network is important in emergency rescue operations while ensuring optimum usage of limited wireless resources. Due to...     

Fault estimation and tolerant control for discrete‐time switched systems with sojourn probabilities

This paper addresses the issue of fault estimation and accommodation for a discrete‐time switched system with actuator faults. Here, we assume that the sojourn probabilities are known a priori. By using the reduced‐order observer method, the sojourn probability approach, and the Lyapunov technique, a fault estimation algorithm is obtained for the considered system. The main objective of this work is to design a dynamic output feedback fault‐tolerant controller based on the obtained fault estimation information such that the closed‐loop discrete‐time switched system with available sojourn probabilities is robustly mean‐square stable and satisfies a prescribed mixed and passivity disturbance attenuation level in the presence of actuator faults. More precisely, a dynamic output feedback fault‐tolerant controller is established in terms of linear matrix inequalities. Finally, numerical examples are provided to illustrate the usefulness and effectiveness of the proposed design technique.     

Impact of Initial pH and Linoleic Acid (C18:2) on Hydrogen Production by a Mesophilic Anaerobic Mixed Culture

Hydrogen production from glucose using a mixed anaerobic culture was assessed under batch conditions by adjusting the initial pH and adding linoleic acid (LA). At an initial pH of 5.0, hydrogen (1.9?mol?H2?mol?1 glucose) was detected after the first glucose injection in the controls (no LA added). At the latter initial pH and in cultures fed 2,000?mg?l?1 LA, the yield reached a maximum of 2.4?mol?H2?mol?1 glucose when glucose was injected again. Hydrogen was detected after the second glucose injection in cultures with the initial pH adjusted to 5.0 and 6.0. In cultures receiving LA and adjusted to pH 7.6, the hydrogen yield reached 1.4?mol?H2?mol?1 glucose when glucose was injected again. Acetate, propionate, and butyrate were detected under all conditions; however, the quantities were variable and dependent on the conditions examined. In comparison to the amount of volatile fatty acids produced, relatively low quantities of alcohols (ethanol, i-propanol, n-butanol, and i-butanol) were detected during the initial lag phase of 96?to?120?h.     

Stabilization of Discrete-time Fuzzy Systems Via Delta Operators and its Application to Truck–Trailer Model

This paper addresses the problem of robust \(L_2{-}L_\infty \) control in delta domain for a class of Takagi–Sugeno (TS) fuzzy systems with interval time-varying delays and disturbance input. In particular, the system under study involves state time delay, uncertainties and fast sampling period \(\mathcal {T}\). The main aim of this work was to design a \(L_2{-}L_\infty \) controller such that the proposed TS fuzzy system is robustly asymptotically stable with a \(L_2{-}L_\infty \) prescribed performance level \(\gamma >0\). Based on the proper Lyapunov–Krasovskii functional (LKF) involving lower and upper bound of time delay and free-weighting technique, a new set of delay-dependent sufficient conditions in terms of linear matrix inequalities (LMIs) are established for obtaining the required result. The result reveals that the asymptotic stability is achieved quickly when the sampling frequency is high. Finally, a numerical example based on the truck–trailer model is given to demonstrate the effectiveness and potential of the proposed design technique.     

Developing a statistical model to predict hydrogen production by a mixed anaerobic mesophilic culture

Optimizing the hydrogen (H₂) yield at several initial pH conditions in a mixed batch anaerobic mesophilic culture fed with glucose and linoleic acid (LA) was performed using a three factor three level Box–Benkhen design (BBD). Based on the BBD approach, a statistical model was developed to predict the H₂ yield. The variables considered for the experimental design were the LA concentration, the initial pH and the number of times glucose was added to the culture. The D-optimality method predicted a maximum H₂ yield of 3.49 mol H₂ mol glucose⁻¹ for cultures fed 1.9 g l⁻¹ LA, maintained at an initial pH of 5.15 and received 1.79 glucose additions. The response outcome (H₂ yield of 3.38 ± 0.22 mol mol glucose⁻¹) at the nearest setting of the experimental factors (2.0 g l⁻¹ LA, an initial pH of 5.0 and two glucose additions) was 3.3% less than the predicted maximum value. The model provides a useful approach for predicting H₂ production when H₂ consumers are inhibited in mixed batch anaerobic cultures.     

Impact of temperature on RF characteristics and electrical noise analysis of an L‐shaped gate tunnel FET with hetero‐stacked source configuration

In this article, a pocket doped hetero‐stacked L‐shaped gate silicon‐on‐insulator (SOI) tunnel FET (HS‐LG‐TFET) has been proposed and investigated. The band‐to‐band tunneling (BTBT) feature of LG‐TFET in a direction perpendicular to the channel facilitates higher ON current due to relatively larger tunneling area. The channel appears to be U‐shaped that is primarily distributed along the vertical direction, which increases the device scalability. Besides, the HS source architecture owns an upper source layer, which consists of larger bandgap material silicon and an underlying source layer, which consists of smaller bandgap material germanium. This underlying layer of smaller bandgap material in HS‐LG‐TFET provides enhanced ON current as well as steeper subthreshold swing behavior. The electrical noise behavior of the proposed structure is addressed to test its viability. Furthermore, a complete radio frequency (RF) characterization, including transconductance, capacitances, cutoff frequency, gain bandwidth product, maximum oscillation frequency, transit time, and minimum noise figure of the proposed device are analyzed to examine its analog applicability. Moreover, for checking the reliability issues associated with temperature, the temperature dependence on transfer and RF characteristics are also explored and presented. Further, the non‐quasi‐static equivalent circuit of the proposed structure is presented to analyze its behavior in the high frequency range.     

Effect of viscous dissipation on finding dual solutions for mixed convection boundary layer flow for nanofluid

The effect of viscous dissipation on mixed convection boundary layer flow for Ag‐water nanofluid under steady‐state condition has been studied numerically for both the buoyancy assisting and opposing flows over a vertical semi‐infinite flat plate. A new co‐ordinate system has been introduced to transform the governing partial differential equations (PDEs) to facilitate the numerical calculations. Then, the local similarity method has been used for approximating the transformed PDEs to ordinary differential equations. Further, the quasi‐linearization method has been introduced to linearize the nonlinear equations and then numerical integration has been carried out using implicit trapezoidal rule along with the principle of superposition. For higher Pr, the coupled differential equations behave like stiff differential equations. To overcome the situation, orthonormalization process has been introduced. The effects of solid volume fraction of nanoparticles , the mixed convection parameter , Prandtl number , and Eckart number have been analyzed on the heat transfer and flow characteristics. It has been observed that the dual solutions are obtained for buoyancy opposing flow only and the range of dual solutions have become wider with the increases in . Further, nanofluids enhance the heat transfer process as compared to conventional heat transfer fluids . Moreover, the addition of viscous dissipation causes less heat transfer in the boundary.     

The beneficial impact of a p–p+ junction on DC and analog/radio frequency performance of a vertical super-thin body FET

This article investigates the impact of the p–p⁺ junction (at the body-substrate interface) on different direct current (DC) and analog/radio frequency (RF) performance parameters of a newly invented structure called vertical super-thin body field effect transistor (VSTB FET) through a well-calibrated TCAD tool. At a fixed body doping, the influence of p–p⁺ junction was inspected for different substrate doping (N_s); which reveals that N_s has a robust control on the device electrostatics. Interestingly, higher N_s is seen to significantly suppress different short channel effects (SCEs), which in turn helps to improve various DC parameters excellently. An increase in N_s from 10¹⁵ to 10¹⁸ cm^?3 improves off-state leakage current and on-to-off current ratio by three orders of magnitude. Also, such a change in N_s decreases subthreshold swing and drain-induced-barrier-lowering by 8.78 mV/dec and 11.15 mV/V, respectively. The underlying physics behind such improvement at higher N_s is explored through the off-state channel electron density profiles corresponding to different N_s values. Further, different analog/RF parameters such as transconductance, input capacitance, gate-drain capacitance, output conductance, gain-bandwidth-product, and transconductance frequency product (TFP) show slight improvement for increasing N_s. In contrast, TGF, GFP, and GTFP offer large enhancement at higher N_s. This study is expected to demonstrate the significance of N_s on device performance.