Unconventional edge detector

An edge detector that does not rely on differentiation or computed digital gradients, but rather on data fitting performed on pixel values within the neighbourhood of each pixel, is described. The edge detector has a nonlinear response with wide dynamic range, and has been tested on several different images     

Neutron and Raman Scattering Studies of Hgba2CuO4+δ

The HgBa₂CuO_4+δ sample was characterized by Neutron diffraction and magnetic measurements. Both of the measurements indicate a high purity of the sample. Raman measurement was performed on a HgBa₂CuO_4+δ compound of T_c = 96 K. The apical oxygen vibration at 592 cm^?1 was found to show (a) an above T_c anomaly, and (b) frequency hardening and linewidth broadening below the superconducting phase transition. The latter is attributed to the coupling of the phonon to the electronic excitation and related to the opening of the superconducting gap below the phonon frequency.     

Confidence limits for steady state availability of systems

A 100% confidence interval for the steady state availability of a system is derived when (i) both the operating time and the repair time distributions are lognormal and (ii) the operating time distribution is inverse Gaussian (IG) and the repair time distribution is lognormal.     

GaInAs/InP DHBT incorporating thick extrinsic base and selectivelyregrown emitter

A novel approach for realising a double heterojunction bipolar transistor (DHRT) with a low base resistance, which incorporates a thick extrinsic base and a regrown emitter is proposed and demonstrated. A combination of selective MOVPE regrowth and selective wet chemical etching resulted in a new self-aligned DHBT structure. Fabricated microwave transistors exhibited good DC and microwave characteristics     

Effect of adiabatic length on the performance of closed-loop thermosyphon system

This paper reports the effect of different adiabatic lengths on the thermal performance of loop thermosyphon with different filling ratios (FRs) and heat inputs. The carbon steel thermosyphon loop for three different adiabatic lengths is used in this analysis. The loop with plate-type, forced air-cooled condenser, along with two vertical inline evaporators, is filled and tested with distilled water. The transient and steady-state analyses are carried out to understand the thermal behavior of the loop. The thermal resistance is found to be lowest at 800-mm adiabatic length and 60% FR. The geyser boiling phenomenon is also noticed in the present thermosyphon loop. The period of oscillation and temperature fluctuations in the evaporator and condenser increase with the adiabatic length. The geyser boiling phenomenon may disappear at a very small adiabatic length of the loop thermosyphon with forced air-cooled condenser. This paper proposes a mathematical model for the loop thermosyphon in terms of the Nusselt number, the Reynolds number, the Prandtl number, and the adiabatic length-to-diameter ratio, and the comparative study shows that proposed model validates the experimental results. Also, it is found that the adiabatic length-to-diameter ratio inversely varies with the Nusselt number.     

Sequential microbial activities mediated bioelectricity production from distillery wastewater using bio-electrochemical system with simultaneous waste remediation

A two-chambered microbial fuel cell (MFC), which can function on the self-driven bio-electrogenic activity operated on anaerobically digested distillery waste (ADDW) i.e. wastewater post anaerobic digestion was designed and fabricated in the laboratory. MFC was evaluated for production of bioelectricity with a simultaneous reduction in the carbon content. Using a surface response methodology with a Box-Behnken design (BBD), operating conditions such as the concentration of antifoam, pH, and resistance were optimized and it was found that the pH and resistance were optimum at 8.3 and 1000 Ω, respectively with no antifoam in the system. Under optimum conditions, 31.49 Wm^?3 was generated, and 60.78 ± 0.95% total organic carbon was degraded. We revealed that the fermentative bacteria generated organic acids mainly acetate from dextrose present in ADDW and electrogenic bacteria oxidized acetate in a successive manner to generate electrons, which was confirmed by gas chromatography. The development of biofilm analyzed by scanning electron microscope (SEM) was found to be crucial in the transfer of electrons directly to the anode and was confirmed by cyclic voltammetry experiments. Identification of bacteria from biofilm by both culture and denaturing gradient gel electrophoresis methods found bacteria belonging to phylum Firmicutes and γ-proteobacteria. The study of successive nature of bacterial metabolism to generate electricity could play an important role in the production of electricity in a continuous mode of operation using MFCs fed with ADDW for further reduction of carbon content post anaerobic digestion for the benefit for the environment. Thus MFC can be used as a complementary technology to anaerobic digestion.     

Aflatoxins and food pathogens: impact of biologically active aflatoxins and their control strategies

Globally disease outbreaks as a result of the consumption of contaminated food and feedstuffs are a regular primary problem. The foremost elements contributing to contamination are microorganisms, particularly fungi, which produce low‐molecular weight secondary metabolites, with demonstrated toxic properties that are referred to as mycotoxins. Aflatoxins contaminate agricultural commodities and may cause sickness or fatality in humans and animals. Moreover, poor conditions of storage and a deficiency in regulatory measures in food quality control aggravate the main issue. For that reason, mycotoxin‐related illness of nutrition represents a major health hazard for local populations. Government policies should make regulations aiming to avoid the entry of aflatoxins into food stuffs. For consumer safety, control and management strategies should be developed and implemented by regulatory authorities. There is the need for attention from farmers, scientists, government and collaborative minds throughout the country to ensure aflatoxin‐free food. The present review is informative not only for health‐conscious consumers, but also for relevant authorities with respect to paving the way for future research aiming to fill the existing gaps in our knowledge with regard to mycotoxins and food security. © 2016 Society of Chemical Industry     

Characterisation of ar ion laser induced cvd silicon films: deposition,crystallographic texture and phosphorous doping

Pyrolytic dissociation of silane on substrates heated by a cw Ar ion laser beam has been used to deposit polycrystalline silicon thin films. The effects of parameters like laser beam irradiance (power density), dwell time, silane pressure on the silicon deposition are studied. To understand the film growth kinetics, an approximate relationship amongst the film thickness and some of the above parameters is deduced from general chemical thermodynamic considerations. The crystallographic texture of the grown silicon film is studied as a function of laser power. It is found that the texture (preferred orientation) changes from 〈110〉 at low power to 〈111〉 at higher power. Mixtures of silane and phosphine at different partial pressures are used to obtain phosphorous doped polysilicon films. These films show a thermally activated conductivity σ = σ₀ exp ( -E _a /kT) with the activation energyE _a depending on the phosphine partial pressure.