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Small-signal model of the MOSFET is an equivalent circuit of its electric components, which defines the electrical characteristics of a MOSFET. The non-quasi-static (NQS) model is one of the most accurate small-signal models used for designing analog/RF circuits. Electronic circuits designed for advanced high-frequency analog/RF applications like (Long-Term Evolution) LTE and (Internet-of-Things) IoT applications, the proper selection of MOSFET is essential. The MOSFETs with lower static power dissipation and high linearity are best suitable for low-power high-frequency analog/digital circuit applications. In this paper, a cylindrical silicon-on-insulator (SOI) Schottky Barrier (SB) MOSFET is investigated, and analog/RF parameters such as transconductance (gm), intrinsic-voltage gain (AV), ION/IOFF ratio, cutoff-frequency (fT), maximum oscillation frequency (fmax), transconductance-generation factor (TGF), gain-frequency product (GFP), transconductance-frequency product (TFP), gain-bandwidth product (GBWP) and gain-transconductance frequency product (GTFP) are extracted. Also, the NQS small-signal model parameters of SOI-SB MOSFET are extracted for the analog circuit application for the frequency range up to 500 GHz. The analog/RF parameters and NQS small-signal parameters of cylindrical SOI-SB MOSFET are compared with cylindrical SB-MOSFET and cylindrical dielectric-pocket (DP) SB-MOSFET. [ABSTRACT FROM AUTHOR]

A facile synthesis of rGO–CuO nanocomposite was carried out using hydrothermal method. rGO–CuO nanocomposite was incorporated in aerosol forming composite (AFC) for the first time in order to develop the fast fire extinguishant materials. Synthesized nanocomposites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, scanning electron microscopy (SEM), energy dispersive Xray spectroscopy (EDX) and transmission electron microscopy (TEM). Catalytic activity of rGO–CuO was analysed considering the parameters such as combustion temperature, activation energy, burn rate, combustion efficiency, minimum fire extinguishing concentration (MEC) and fire extinguishing time. Addition of rGO–CuO to base AFC remarkably enhanced the performance of AFC by increasing the combustion efficiency (11.36%) and decreasing the combustion temperature (16.14%) and MEC (19.78%). A tremendous increase in burn rate (47.1%) boosted the fast extinguishment of fire by reducing the fire extinguishment time 78.2%. Developed AFC found promising to meet the faster fire extinguishment requirement of futuristic fire suppression systems. [ABSTRACT FROM AUTHOR]

rGO/Fe2O3 nanocomposites were synthesized using facile and inexpensive hydrothermal route. For the first time, these nanocomposites were incorporated in aerosol forming composites (AFCs), characterized and investigated for ultra-fast fire extinguishing applications. The morphological and structural characteristics were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transmission infrared spectroscopy (FTIR), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX). AFCs were also characterized for burn rate, combustion efficiency, minimum fire extinguishing concentration, fire extinguishing time, combustion temperature and activation energy. Characterization revealed successful synthesis of rGO/Fe2O3 nanocomposites having Fe2O3 nanoparticles (25–50 nm) over and in-between the graphene oxide nanosheets. Increase in combustion efficiency (9%) and burn rate (35%) and reduction in onset temperature (17.16%), combustion temperature (13.46%) and activation energy (37.71%) were observed on addition of 3% rGO/5.0Fe2O3 nanocomposite to base AFC. Increase in burn rate by 35% led to ultra-fast aerosol generation and faster (50% reduction in fire extinguishing time) fire extinguishment. AFCs found promising for incorporation in condensed aerosol-based fire extinguishing systems to comply futuristic quicker fire extinguishment requirements. [ABSTRACT FROM AUTHOR]

Aerosol forming composite (AFC) is an important component of condensed aerosol-based fire extinguishing system (CAFES). As per literature no attempts have been made so far for the detailed study of AFCs. Therefore, for the insight AFCs were prepared with potassium nitrate as an oxidizer and phenol formaldehyde resin as a combustible binder. Five metal oxides, namely MnO2, Fe2O3, NiO, CuO and CeO2, (3%, w/w) were added as catalysts in AFC. The catalytic effect of these metal oxides was investigated for various parameters such as combustion efficiency, burn rate, minimum fire extinguishing concentration (MEC), decomposition temperature and activation energy. Addition of CuO, 3%, w/w increased the burn rate of AFC by 51.4% and reduced the MEC by 29.4%. Thermogravimetric analysis and differential scanning calorimetry analysis clearly indicated the reduction in decomposition temperature from 445.65 to 396.48 °C while adding CuO. Activation energies of decomposition for base AFC and AFC-CuO calculated using model-free methods of Kissinger, Ozawa–Flynn–Wall and Kissinger–Akahira–Sunose were found to be 181.12, 183.50 and 180.75 kJ/mol and 146.61, 149.98 and 163.18 kJ/mol, respectively. The functions 1−(1−α)2/3 (model F1/3: One-third order) and [1−(1−α)1/2] (model R3, F2/3: power law) were found as the most probable mechanism for the thermal decomposition of base AFC and CuO-AFC, respectively. Aerosol characterization with X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning electron microscopy and particle counter indicated mostly 2 µm particles of potassium carbonate/bicarbonate. Total flooding and dispersion characteristics of aerosols were confirmed using pH measurements at various locations. Overall, prepared AFCs were found promising for use within CAFES. [ABSTRACT FROM AUTHOR]

Implementation of Montreal Protocols-1987 enforced phase wise ban on production and application of ozone depleting chemicals (Halons). Since then, condensed aerosol-based fire extinguishing technology as an alternative to Halons has been a subject for numerous investigations for its research and applications worldwide. It has come up as the most efficient halon alternative technology in comparison to other alternatives such as water mist, dry powders, inert gases, hydro fluorocarbons, and carbon dioxide. Even it is three times more efficient than that of Halon 1301 on weight to volume basis. Over other Halon alternatives, it has many advantages, e.g., zero ozone depletion potential -atmospheric lifetime -global warming potential, modular structure, low space requirements, easy & cost-effective installation & maintenance, no requirement of piping & pressurized cylinders, no oxygen depression etc. Condensed aerosol based fire extinguishing systems (CAFES) have found versatile fire safety applications worldwide in many areas such as power generation, transportation, storage rooms, public buildings, heavy industries, battery storage systems, defence etc. This review mainly focuses on applications of CAFES for extinguishment of: class A fires in libraries, archives, storage rooms etc.; class B fires in machinery spaces, gas turbine enclosures, combat vehicles, chemical storage rooms; electrical fires occurring in control rooms, UPS rooms, electrical/power substations & panels. Various reports and case studies demonstrating its testing and implementation methodologies have also been covered. The future prospects of aerosol technology and potential research/applications areas are also discussed. [ABSTRACT FROM AUTHOR]

Aerosol forming compositions (AFCs) have come up as one of the most efficient fire extinguishing Halon alternative since the implementation of Montreal protocol-1987 on ozone layer depleting substances. These aerosol based systems have gained much attention in recent years because of higher fire extinguishing efficiencies, modular nature, non pressurized container, less maintenance requirement, extended shelf-life and negligible ODP, GWP and ALT values. Aerosols are traditionally produced using pyrotechnique compositions having mostly metal salts of group IA or IIA. Potassium nitrate has been used predominantly as oxidizing agent (40–75%, w/w), whereas for electric and electronics systems, strontium nitrate (15–70%, w/w) has been recommended. Versatile reducing agent, binders, gas forming agents, burn rate modifiers and many such functional additives have been used recently for preparations of AFCs. AFCs indicated variable burn rate values, 2–7 mm/s. AFCs were found highly efficient with minimum fire extinguishing concentrations mostly ranging between 30 g/m3 and 200 g/m3. Moreover, the development of highly efficient, non-corrosive, non-toxic and environmentally benign AFC is still an elusive goal. This review mainly focuses on advances of aerosol forming chemical compositions, its future prospects and potential research areas. [ABSTRACT FROM AUTHOR]

The underbalanced drilling fluid plays a vital role in the field of exploration of coal bed methane and tight gas reservoirs. It is used to minimize the formation damage and other drilling associated problems. Foam is considered as a popular alternative over the air in underbalanced drilling operations. Development of stable and uniform foam and prediction of its rheological behaviour under dynamic borehole conditions are real challenges in the successful drilling operations. If not designed properly, drilling fluid will fail to transport the cuttings to the surface efficiently. The present study focuses on the development of an empirical correlation for settling velocity of solid cuttings through gelled foams. A number of solids such as coal, sand and shale with variable particle sizes were selected for the present study. Foam fluids prepared with different compositions were characterized. Effects of various parameters such as foam density, composition, viscosity, gel strength, stability and quality, which control the hydrodynamic behaviour during drilling, were studied in detail. The settling velocities of cuttings were experimentally determined for foams with variable compositions. An empirical model has been developed for settling velocity of solid cuttings through gelled foams. This correlation is validated using different solid-fluid experimental data. The model is found to satisfactorily trace the experimental data. This model can be used in designing and characterizing the gelled foam better than the existing models. [ABSTRACT FROM AUTHOR]

Purpose: Inflammation following arterial injury mediates vascular restenosis, a leading cause of cardiovascular morbidity. Here we utilize intravital microscopy (IVM) and a dextran-coated nanosensor to spatially map inflammatory macrophages in vivo following endovascular injury of murine carotid arteries. Procedures: C57Bl/6 mice ( n = 23) underwent endovascular guidewire carotid arterial injury. At day 14 or day 28 post-injury, mice underwent fluorescence IVM, 24 h after injection with the near-infrared fluorescent macrophage nanosensor CLIO-VT680. Adventitial collagen was concomitantly imaged using second harmonic generation (SHG) IVM. Correlative fluorescence microscopy and immunohistochemistry were performed. Results: Two-plane IVM reconstructions detected macrophage inflammation in the arterial wall that was elevated at day 14 compared to day 28 animals ( P < 0.05). SHG-based collagen imaging of the outer arterial wall facilitated analysis of the macrophage-rich, inflamed neointima. Histological analyses and fluorescence microscopy data demonstrated increased macrophage infiltration in day 14 compared to day 28 neointima. Conclusions: We demonstrate that the macrophage response to arterial injury can be imaged in vivo using IVM-based molecular imaging, and shows a higher macrophage influx at day 14 compared to day 28 post-injury. [ABSTRACT FROM AUTHOR]

We describe here the paradoxical development of spontaneous experimental autoimmune encephalomyelitis (EAE) in transgenic mice expressing a myelin oligodendrocyte glycoprotein (MOG)-specific T cell antigen receptor (TCR) in the absence of MOG. We report that in Mog-deficient mice (Mog−/−), the autoimmune response by transgenic T cells is redirected to a neuronal cytoskeletal self antigen, neurofilament-M (NF-M). Although components of radically different protein classes, the cross-reacting major histocompatibility complex I-Ab–restricted epitope sequences of MOG35–55 and NF-M18–30 share essential TCR contact positions. This pattern of cross-reaction is not specific to the transgenic TCR but is also commonly seen in MOG35–55–I-Ab–reactive T cells. We propose that in the C57BL/6 mouse, MOG and NF-M response components add up to overcome the general resistance of this strain to experimental induction of autoimmunity. Similar cumulative responses against more than one autoantigen may have a role in spontaneously developing human autoimmune diseases. [ABSTRACT FROM AUTHOR]

For low-power circuit applications, the performance of the circuit is significantly influenced by the MOSFET's analog/RF and non-linearity properties. Gate-all-around junction-less accumulation mode MOSFETs (JAM) are now the perfect choice for low-power circuit applications. In the present work, the gate-stack engineering method is used for gate-all-around junction-less accumulation mode MOSFET (GSJAM) to improve the analog/RF characteristics. The analog/RF and linearity parameter analyses are numerically performed for a 20 nm channel length gate-all-around gate-stacked junction-less MOSFET using an ATLAS 3D device simulator. The comparative analysis of these analog/RF and linearity parameters is also done. The gate stack engineering shows significant improvements in analog/RF parameters, i.e., trans-conductance (gm), output resistance (Rout), early voltage (Vea), intrinsic gain (AV), trans-conductance frequency product (TFP), gain frequency product (GFP), trans-conductance generation factor (TGF), gain bandwidth product (GBWP), gain trans-conductance frequency product (GTFP), and cut-off frequency (fT). The results of the simulation investigation show that when GSJM is compared to JAM MOSFET, the values of gm, Rout, Vea, and TGF are all 26.37%, 2.24 times, 22.38%, and 20.78% higher, respectively. Also, the gate-stack junction-less MOSFET improves the linearity parameters, i.e., 2nd -order trans-conductance (gm2), 3rd -order trans-conductance (gm3), VIP2, VIP3, IIP3, IMD3, and 1-dBCP. When comparing GSJAM to JAM MOSFET, the values of VIP2 are 81.63% higher, VIP3 is 1.77 times higher, IIP3 is 6.72 times higher, and 1-dBCP is twice as high. Further, for analog/RF applications, a 20 nm CMOS common-source voltage amplifier circuit using gate-stake junction-less MOSFET has also been designed for a 20 mV and 1 GHz sinusoidal input signal. [ABSTRACT FROM AUTHOR]

The small signal model of MOSFET is a must for implementation of analog/digital circuits. The non-quasi-static (NQS) model is well known and provides accurate parameters for MOSFET. In the present work, extrinsic and intrinsic NQS model parameters were extracted for 20 nm Gate Stacked Junction-less Accumulation Mode (GSJAM) MOSFET using two-port admittance parameters. Further, for analog/RF applications, the first order active high pass filter (HPF), low pass filter (LPF) and second order active HPF, LPF are implemented using 20 nm GSJAM MOSFET. The first order and second order active filters are implemented for 10 GHz circuit applications. For amplifying the processed filtered input signal, a CMOS single stage common source voltage amplifier is used in the output circuit. Filter circuits use GSJAM N-type MOSFET as an active load in conjunction with a passive capacitor. With cut-off frequency, further bode-plot analysis of the low pass filter and high pass filter circuits is conducted. For numerical simulation, the well-known silvaco CAD tool is used. [ABSTRACT FROM AUTHOR]

In recent times Gallbladder cancer (GBC) incidences increased many folds in India and are being reported from arsenic hotspots identified in Bihar. The study aims to establish association between arsenic exposure and gallbladder carcinogenesis. In the present study, n = 200 were control volunteers and n = 152 confirmed gallbladder cancer cases. The studied GBC patient's biological samples-gallbladder tissue, gallbladder stone, bile, blood and hair samples were collected for arsenic estimation. Moreover, n = 512 gallbladder cancer patients blood samples were also evaluated for the presence of arsenic to understand exposure level in the population. A significantly high arsenic concentration (p < 0.05) was detected in the blood samples with maximum concentration 389 µg/L in GBC cases in comparison to control. Similarly, in the gallbladder cancer patients, there was significantly high arsenic concentration observed in gallbladder tissue with highest concentration of 2166 µg/kg, in gallbladder stones 635 µg/kg, in bile samples 483 µg/L and in hair samples 6980 µg/kg respectively. Moreover, the n = 512 gallbladder cancer patient's blood samples study revealed very significant arsenic concentration in the population of Bihar with maximum arsenic concentration as 746 µg/L. The raised arsenic concentration in the gallbladder cancer patients' biological samples—gallbladder tissue, gallbladder stone, bile, blood, and hair samples was significantly very high in the arsenic exposed area. The study denotes that the gallbladder disease burden is very high in the arsenic exposed area of Bihar. The findings do provide a strong link between arsenic contamination and increased gallbladder carcinogenesis. [ABSTRACT FROM AUTHOR]

An efficient method for the preparation of 1,3-dithiolanes of aliphatic and both activated and deactivated aromatic carbonyl compounds with 1,2-ethanedithiol in the presence of a catalytic amount of inexpensive, easily recyclable, monodispersed, chemoselective Ni-nanoparticles having high TON and TOF is reported. An efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using Ni-nanoparticles is also reported in this article. Our reaction is kinetically controlled and the method is relatively expedient, avoids the use of cost-prohibitive reagents, high temperatures and leads to excellent yield. Selective Protection of Carbonyl Compounds Over Nano-sized Nickel Catalysts Ajeet Kumar,a Santosh Kumar,a Amit Saxena,a Arnab De,b Subho Mozumdara* aDepartment of Chemistry, University of Delhi, Delhi, 110007, India; b Department of Chemistry, Indiana University, Bloomington, USA; subhoscom@yahoo.co.in An efficient method for the preparation of 1,3-dithiolanes of aliphatic and both activated and deactivated aromatic carbonyl compounds with 1,2-ethanedithiol in the presence of a catalytic amount of inexpensive, easily recyclable, monodispersed, chemoselective Ni-nanoparticles having high TON and TOF is reported. We report an efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using Ni-nanoparticles. Our reaction is kinetically controlled and the method is relatively expedient, avoids the use of cost-prohibitive reagents, high temperatures and leads to excellent yield. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]