Modeling & Simulation of High Performance Nanoscale MOSFETs

Silicon-on-insulator (SOI) has been the forerunner of the CMOS technology in the last few decades offering superior CMOS devices with higher speed, higher density and reduced second order effects for submicron VLSI applications.A new type of transistor without junctions and no doping concentration gradients is analysed and demonstrated. These device structures address the challenge of short channel effects (SCEs) resulting with scaling of transistor dimensions and higher performance for deep submicron VLSI integration. Recent experimental studies have invigorated interest in partially depleted (PD) SOI devices because of their potentially superior scalability relative to bulk silicon CMOS devices. SELBOX structure offer an alternative way of suppressing kink effect and self heating effects in PD-SOI devices with a proper selection of oxide gap length. Also in order to mitigate the difficulties in fabrication of ultra thin devices for the semiconductor industry, resulting from scaling of gate length in MOSFET, a new device structure called junctionless (JL) transistors have recently been reported as an alternative device. In conclusion, extensive numerical simulation studies were used to explore and compare the electrical characteristics of SELBOX SOI MOSFET with a conventional single-material gate (SMG) bulk MOSFET. The proposed work investigates the DC and AC characteristics of the junctionless transistors. Also the performance analysis of JL transistors is compared and presented with the conventional DG MOSFET structure. The results presented in this work are expected to provide incentive for further experimental exploration

Effects of Salinity on Leaf and Grain Protein in Some Genotypes of Oat (Avena sativa L.)

The protein content in oat, like in the other cereal species, is much influenced by the environmental conditions as well as by the variety. This investigation was carried out on the effect of salinity on protein content in leaves and grains of four genotypes of oat (JHO-822, JHO-851, Kent and UPO-94). The plants were irrigated with different saline waters (3, 6, 7.2, 10, 12 and 14 dSm-1) in the field. Protein in leaf was analyzed at 90 days after sowing. Cv. JHO-822 and JHO-851 contained higher leaf protein at 3 and 6 dSm-1 but lower at 7.2 to 14 dSm-1. Kent and UPO-94 registered an increase in leaf protein only at 3 dSm-1 but declined at all salinities. Grain protein of cultivars of oat also registered significant enhancement at 3 dSm-1 but significant reductions at other salinities. The higher protein content in leaves and grains in cv. JHO-822 may be due to higher photosynthetic rate of plants due to higher total leaf area

FIELD INVESTIGATIONS INTO HARMONICS POLLUTION AFFECTING TRANSFORMERS

Field investigations on harmonics caused by loads are essential to have a quantitative visualization and formation of premise of research. Field investigations have been carried out covering spectrum of loads and voltage levels right from generation to consumers, as at present. Investigations have revealed that low tension consumers form cluster of non-linear loads and are major contributors of current harmonics. Traction loads are another major category of harmonic pollutant. Industrial consumers do provide reactive compensation which helps to filter out current harmonics partially. However, in absence of any regulatory measure consumers keep polluting current harmonics into the system and also bear with the consequential disturbances. Voltage harmonics are significant only at leaf ends of distribution distribution system, where source impedance, seen by the harmonics generated by the load, is high. Tranasformer is the first major equipment in power system to intercept the harmonics. These harmonics caused accelerated ageing of transformers and even objectionable rise of temperature of cover-plate and turets

FIELD INVESTIGATIONS INTO HARMONICS POLLUTION AFFECTING TRANSFORMERS

Field investigations on harmonics caused by loads are essential to have a quantitative visualization and formation of premise of research. Field investigations have been carried out covering spectrum of loads and voltage levels right from generation to consumers, as at present. Investigations have revealed that low tension consumers form cluster of non-linear loads and are major contributors of current harmonics. Traction loads are another major category of harmonic pollutant. Industrial consumers do provide reactive compensation which helps to filter out current harmonics partially. However, in absence of any regulatory measure consumers keep polluting current harmonics into the system and also bear with the consequential disturbances. Voltage harmonics are significant only at leaf ends of distribution distribution system, where source impedance, seen by the harmonics generated by the load, is high. Tranasformer is the first major equipment in power system to intercept the harmonics. These harmonics caused accelerated ageing of transformers and even objectionable rise of temperature of cover-plate and turets

Preliminary experience of fractionated stereotactic radiosurgery with extend system of Gamma Knife

Purpose: The purpose of this study is to present multisession stereotactic radiosurgery with initial experience using custom made extend system (ES) of Gamma Knife.Methods: The ES is comprised of a carbon fiber frame also called extend frame, vacuum head rest cushion, patient surveillance unit and a configurable front piece with dental impression tray. The extend frame is a rigid connection between patient's head and patient positioning system (PPS) of Gamma Knife. A dental impression of patient was created and attached to the frontal piece of extend system. The treatment setup involves positioning the patient within the extend frame using patient specific headrest cushion and front piece. The reference patient’s head position was recorded through measurements of repositioning check tool (RCT) apertures using a high precision digital probe before computed tomography (CT) scan. The RCT measurements taken before treatment were compared with recorded reference position to ensure appropriate patient treatment position. Volumetric magnetic resonance (MR) scan was co-registered with stereotactic CT scan on Leksell Gamma plan. Fused MR to CT images on Gamma Plan was utilized to delineate regions of interest and prepare a precise treatment plan. The presented study includes positional reproducibility check and dosimetric evaluation of ten patients treated with ES.Results: Forty-three fractions on ten patients with prescribed treatment format were delivered successfully. An average tumor volume of 11.26 cm3 (range, 340 mm3 to 59.12 cm3) was treated with ES. The mean tumor coverage of 91.91% (range, 90% to 95%) was able to achieve at 50% prescription isodose without compromising adjacent normal structure radiation dose tolerances. The mean inter-fraction positional variation of 0.69 mm influences an inherent strength of immobilization technique. Follow-up of seven patients at a median interval of 16 months (range, 9 months to 26 months) showed evidence of 100% radiographic control with improved clinical results.Conclusion: Conjugative clinical outcome shows the efficacy of fractionation in various clinical indications

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ+μ−μ+μ− double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb−1. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ+μ− decay as normalization, the branching fraction B(η→μ+μ−μ+μ−)=[5.0±0.8(stat)±0.7(syst)±0.7(B2μ)]×10−9 is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions

Search for new physics in multijet events with at least one photon and large missing transverse momentum in proton-proton collisions at 13 TeV

A search for new physics in final states consisting of at least one photon, multiple jets, and large missing transverse momentum is presented, using proton-proton collision events at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 137 fb−1, recorded by the CMS experiment at the CERN LHC from 2016 to 2018. The events are divided into mutually exclusive bins characterized by the missing transverse momentum, the number of jets, the number of b-tagged jets, and jets consistent with the presence of hadronically decaying W, Z, or Higgs bosons. The observed data are found to be consistent with the prediction from standard model processes. The results are interpreted in the context of simplified models of pair production of supersymmetric particles via strong and electroweak interactions. Depending on the details of the signal models, gluinos and squarks of masses up to 2.35 and 1.43 TeV, respectively, and electroweakinos of masses up to 1.23 TeV are excluded at 95% confidence level