Analytical Modeling of Line-Tunneling TFETs Based on Low-Bandgap Semiconductors

The combination of two techniques: low-bandgap semiconductor and line-tunneling structure is an effective way to achieve the highest on-current in TFETs. In this paper, design of low-bandgap line-tunneling TEFT and its analytical modeling of drain current equation is proposed. The previously suggested drain current equation for the low-bandgap line-tunneling TEFT has been explained in a relatively complex form based on the minimum tunnel path that is an effective factor in determining band-to-band tunneling (BTBT). It has been simplified in this paper and reformulated based on gate-to-source voltage. Important design factors such as source doping concentration, material and thickness of the gate-insulator were examined by simulation and numerical calculations based on the minimum tunnel path for two low-bandgap In0.88Ga0.12As and relatively high-bandgap GaSb semiconductors. The comparison of the results obtained from simulations with the proposed analytical drain current model show a good agreement. Drain doping concentration, is an effective factor on the off-state current of low-bandgap TFET. This factor was examined in order to reduce the off-current.

A Review on the Study of Temperature Effects in the Design of A/D Circuits based on CNTFET

In this paper, we review a procedure to study the effects of temperature in the design of A/D circuits based on CNTFETs. At first, we briefly describe a compact model, already proposed by us, in which the temperature variation in the drain current equation and in energy band gap is considered. Then, the effects of temperature variations in the design of analog circuits, such as a cascode current sink mirror and an Operational Transconductance Amplifier (OTA), and in the design of digital circuits including in particular NAND and NOR logic gates, are illustrated and widely discussed.

Arc Voltage and Current Characteristics in Low-Voltage Direct Current

Recently, Low-Voltage DC (direct current) distribution systems have received high lights according to the expansion of DC generations and DC loads such as photovoltaics (PV) generations, electric vehicles (EVs), light emitting diodes (LEDs), computers, DC homes, etc. Low-Voltage DC distribution systems have optimistic perspectives since DC has various good aspects compared to alternating current (AC). However, ensuring safety of human and electric facility in Low-Voltage DC is not easy because of arc generation and difficulty of arc-extinguishing. This paper constructs a low-voltage DC circuit and studies the arc interruption that occurs when separating electrodes from where load currents flow. Also, arc extinguishers are experimented upon and analysed in various levels of source voltage and load currents conditions. Voltage and current characteristics for arc interruption are identified based on experimental results, and we establish the electric generation for arc interruption. Further, the voltage–current characteristics and the correlation of arc during arc duration time arc are verified, and the voltage–current equation and DC arc resistance model for the breaking arc are developed.

Technical Note: Alternative in-stream denitrification equation for the INCA-N model

The Integrated Catchment model for Nitrogen (INCA-N) is a semi-distributed, process based model that has been used to model the impacts of land use, climate, and land management changes on hydrology and nitrogen loading. An observed problem with the INCA-N model is reproducing low nitrate–nitrogen concentrations during the summer growing season in some catchments. In this study, the current equation used to simulate the rate of in-stream denitrification was replaced with an alternate equation that uses a mass transfer coefficient and the stream bottom area. The results of simulating in-stream denitrification using the two different methods were compared for a one year simulation period of the Yläneenjoki catchment in Finland. The alternate equation (Nash–Sutcliffe efficiency = 0.61) simulated concentrations during the periods of the growing season with the lowest flow that were closer to the observed concentrations than the current equation (Nash–Sutcliffe efficiency = 0.60), but the results were mixed during other portions of the year. The results of the calibration and validation of the model using the two equations show that the alternate equation will simulate lower nitrate–nitrogen concentrations during the growing season when compared to the current equation, but promote investigation into other errors in the model that may be causing inaccuracies in the modeled concentrations.

OCTONION ELECTRODYNAMICS IN ISOTROPIC AND CHIRAL MEDIUM

In order to understand the self-consistent theory of dyons, we have undertaken the study of octonion analysis of generalized Dirac–Maxwell's (GDM) equations of dyons in isotropic medium and chiral medium. Consequently, we have developed the octonion forms of potential, field and current equation of dyons in simple and compact manner in homogeneous or isotropic medium. It is emphasized that the corresponding quantum equations are invariant under Lorentz and duality transformations. Furthermore, the generalized electrodynamics of dyons in chiral medium has also been discussed in terms of simple, compact and consistent octonion analysis. It is shown that in the absence of chiral parameter the theory of dyons reduces to that for homogeneous (isotropic) medium. The generalized theory of dyons in chiral medium thus reproduces the field equation of moving charge particle-like electron (monopole) in the absence of monopole (electron) in vacuum if we consider neither chiral nor isotropic medium parameters therein.