C5: A Step Towards Smart World with Enhanced Holistic Wellbeing

Wireless Personal Communications - Internet of things (IoTs) has been the smartest technology proven worldwide these days. The application products of IoTs are Mobile ad hoc network (MANET) and...     

Green biomass bistable transistor multivibrator

For the first time a biomass bistable transistor multivibrator using an NPN Philips transistor as the active device and freshly plucked green Champo (Plumaria rubra) leaf cuttings as electrical components (resistance R and capacitance C) has been realized. The frequency and other parameters of the generated pulses, along with the circuit configuration, are presented. The development envisages a novel march towards a green revolution in electronic circuitry.     

Conformal Band Notched Circular Monopole Antenna Loaded with Split Ring Resonator

This article presents the design and analysis of conformal circular monopole antenna with split ring resonator to get frequency notch characteristics in the wideband. Split ring resonators placed on one side of the substrate and complementary split ring resonators placed on the other side of the substrate at defected ground structure, which yields the frequency notch characteristics with respect to the microstrip feeding. Dual notch band characteristics are obtained between 4–4.3 and 7.3–8.1 GHz. The analyzed conformal characteristic of the antenna supports excellent constant reflection coefficient characteristics over the band at different angles. The impedance and radiation characteristics of the antenna model is analysed in simulation along with unit cell analysis of the SRR and the measured results are providing good agreement with them.     

Synergistic interaction of 2-amino 4-methyl benzothiazole (AMBT) and benzotriazole (BTZ) offers excellent protection to mild steel exposed in acid atmosphere at elevated temperatures: Electrochemical,computational and surface studies

The synergistic interactions and corrosion protection properties of 2-amino 4-methyl benzothiazole, (AMBT) and 1, 2, 3-benzotriazole (BTZ) have been studied for mild steel in HCl at elevated temperatures. The extent of synergistic interaction increases with temperature. The methods of study include the conventional weight loss studies, computational screening, surface characterization and electrochemical studies. Quantum chemical approach was used to calculate some electronic properties of the molecules and to ascertain the synergistic interaction, inhibitive effect and molecular structures. The corrosion inhibition efficiencies and the global chemical reactivity relate to parameters like total energy, E_HOMO, E_LUMO and gap energy (ΔE). Condensed atom Fukui functions also calculated using DFT at B3LYP/6-31G* level, and were found to be correlating with the experimental results.     

An overview of CDMA evolution toward wideband CDMA

Third-generation mobile radio networks, often dubbed as 3G, have been under intense research and discussion recently and will emerge around the year 2000. In the International Telecommunications Union (ITU), third generation networks are called International Mobile Telecommunications-2000 (IMT-2000), and in Europe, Universal Mobile Telecommunications System (UMTS). IMT-2000 will provide a multitude of services, especially multimedia and high-bit-rate packet data. Wideband code division multiple access (CDMA) has emerged as the mainstream air interface solution for the third-generation networks. In Europe, Japan, Korea, and the United States, wideband CDMA systems are currently being standarized. This article provides a comprehensive introduction to wideband CDMA. It also provides a review of the wideband CDMA air interface proposals including WCDMA in Europe and Japan, cdma2000 in the United States, and wideband CDMA in Korea.     

Intermodulation analysis of the collector-up InGaAs/InAlAs/InP HBTusing Volterra series

The intermodulation (IM) distortion of the collector-up InGaAs/InAlAs/InP heterojunction bipolar transistor (HBT) is analyzed using Volterra-series theory. A T-equivalent circuit is used for this analysis. The contribution and interaction of four nonlinear elements: base-emitter resistance, base-emitter capacitance, base-collector capacitance, and common base-current gain are analyzed. For the particular device under investigation, it is found that the cancellation effect is not significant and the base-emitter resistance nonlinearity dominates the third-order IM     

Optimum tilt of solar collector for maximum natural flow

A theoretical treatment to determine the natural flow rate through a flat plate collector having heat losses is made. The governing equations have been expressed in terms of Grashof and Prandtl numbers and a dimensionless heat loss parameter. The method predicts the optimum tilt of the flat plate collector for the maximum draught for a given latitude and insolation. The experimental verification of the theoretical results shows a fair agreement.

A method to calibrate the hot wire anemometer at the desired temperature is evolved for the range of velocities encountered in practice for the flat plate solar collector.     

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.     

Spectrum efficiency analysis for microcellular mobile radio systems

Spectrum efficiency is analysed in a microcellular mobile radio environment considering an appropriate model for UHF ground-wave path loss. The influence of cluster size and reuse distance on the spectrum efficiency is investigated by obtaining the probability of cochannel interference for uncorrelated Rayleigh fading interferers and Rician fading desired signal. The effect of traffic intensity is also considered in evaluating the spectrum efficiency.<>     

Function dependent fully testable programmable logic array

Two techniques for designing function-dependent easily testable programmable logic arrays are presented. The techniques can detect all the multiple stuck-at, crosspoint and bridging faults, as compared with most of the existing techniques where some of the faults, especially bridging faults, remain undetected.<>