Temperature behavior and compensation of light-emitting diode

This letter offers a fresh insight into the behavior of light-emitting diode (LED) over temperature. Theoretically and by measurement, it has been shown that equi-intensity curves in the diodes current-voltage plane are nearly a straight line over a very wide range of temperatures. Based on this property, bias voltage and resistance value of a bias circuit have been realized and practical measurement shows the peak-to-peak light intensity variation decreases from 99 % (in case of fixed current bias) to 6 % over the temperature range of -20 C to +80 C for the LED IN6092. This circuit uses no separate temperature sensor or compensating mechanism, but responds directly to the junction temperature of the diodes. This prevents any error caused by temperature gradient, or by self-heating due to power dissipation in the diode.     

Parasitic extraction: current state of the art and future trends

With the increase in circuit performance (higher speeds) and density (smaller feature size) in deep submicrometer (DSM) designs, interconnect parasitic effects are increasingly becoming more important. This paper first surveys the state of the art in parasitic extraction for resistance, capacitance, and inductance. The paper then covers other related issues such as interconnect modeling, model order reduction, delay calculation, and signal integrity issues such as crosstalk. Some future trends on parasitic extraction, model reduction and interconnect modeling are discussed and a fairly complete list of references is given     

Prospects of manufacturing organic semiconductor-based integratedcircuits

The driving force for developing organic thin-film transistor (OTFT)-based electronics is the fact that they are flexible, lightweight and have the prospect of low-cost manufacturing. Major barriers in the practical realization of OTFT-based electronic systems are the need for larger power supplies, lower gain, lower switching speeds and reliability problems. New directions leading to changes in the design of transistors, materials used in the fabrication, and processing techniques are warranted for developing process and equipment that can lead to the manufacturing of OTFT-based electronics. For developing dense OTFT-based electronics, the low thermal conductivity (as compared to silicon) of organic semiconductors is a fundamental problem. The use of nanodimension polymers with homogeneous microstructure, transistors operating in subthreshold region and the use of new materials (high and low dielectric constant dielectric materials as well as Cu as the conductor for interconnections) for fabricating transistors and a novel rapid photothermal processing technique for depositing thin films of organic semiconductors as well as for reducing the defects introduced during processing are some of the proposed directions that may lead to the manufacturing of OTFT based electronics     

Optical orthogonal code design using genetic algorithms

A construction technique for optical orthogonal codes (OOCs) using genetic algorithms (GAs) is proposed. The performance of the GA OOCs is compared to that of four existing OOCs. Results show that the GA OOCs have a lower probability of error     

QoS-Aware Optical Fog-Assisted Cyber-Physical System in the 5G Ready Heterogeneous Network

Wireless Personal Communications - In recent years, the emergence of Internet of things and cyber-physical system provide a proactive and efficacious solution to enable remote monitoring, machine...     

Energy Efficient Multitier Random DEC Routing Protocols for WSN: In Agricultural

Wireless Personal Communications - Fog computing is an emerging paradigm that provides confluence facilities between Internet of Things (IoT) devices and cloud. The fog nodes process the...     

13C CP/MAS NMR Spectroscopy of Native and Acid Modified Starches

¹³CP/MAS NMR spectroscopic studies of some starches from cereals (wheat, maize and finger millet), pulses (green gram, chick pea), tuber (potato) and root (tapioca), and their respective acid (HCI, HNO₃) modified starches were carried out. While cereal starches exhibited a triplet signal for their anomeric carbons, pulse, tuber and root starches showed doublets. Line width changes in signals indicated that debranching in the above modified starches led to narrowing of C₆ signals (more pronounced in the case of potato and tapioca starches) and were consistent with the release of branching strains. Potato starch, both native and modified, was found to be different from other starches as inferred from the chemical shift values for their anomeric carbons and line shape. The dihedral angle (ϕ′2) calculated from chemical shift values for C₁ and conformation of dihedral angel (x) as predicted from chemical shift of C₆ are discussed with respect to structural organization.     

A new control approach to three-phase active filter for harmonicsand reactive power compensation

This paper deals with a new control scheme for a parallel 3-phase active filter to eliminate harmonics and to compensate the reactive power of the nonlinear loads. A 3-phase voltage source inverter bridge with a DC bus capacitor is used as an active filter (AF). A hysteresis based carrierless PWM current control is employed to derive the switching signals to the AF. Source reference currents are derived using load currents, DC bus voltage and source voltage. The command currents of the AF are derived using source reference and load currents. A 3-phase diode rectifier with capacitive loading is employed as the nonlinear load. The AF is found effective to meet IEEE-519 standard recommendations on the harmonics level     

Impact of coal mining on mine water quality

The coal mining industry has to dispose of millions of litres of water every day. This water forms main source of various water supplies in the thickly populated coalfields. In this study, water samples from major coalfields were collected and analysed in an attempt to reflect the impact of mining on water quality in these areas. Various physico-chemical characteristics of mine waters as analysed include pH, alkalinity/acidity, specific conductivity, hardness, total solids, sulphate, chloride iron and trace materials. This investigation reveals that mining activity, markedly pollute the mine waters. Mine waters are of highly complex nature and of widely varying composition. These are nearly neutral, alkaline, mildly acidic and highly acidic in nature. Special emphasis on water quality deterioration due to acid mine drainage which result in significant concentration levels of tract (toxic) metals, is given. A classification of these mine waters is also made.     

35 GHz dielectric resonator stabilised gunn oscillator

A 35 GHz dielectric resonator oscillator(DRO) using GaAs Gunn diode in microstrip configuration has been designed and developed. The oscillator, with an integral waveguide-to-microstrip transition, delivered an output greater than 18 dBm. Phase noise of the oscillator is found to be better than ?80 dBc/Hz at 100 KHz away from the carrier. A frequency drift of about ±25 MHz has been observed over the temperature range from ?10 °C to 50 °C.