Physical Sciences and Engineering

Solar and wind promises to be a clean supply of renewable energy. The variation in the energy level of these sources due to various environmental factors can put together the entire system into chaos. This necessitates robust DC-DC converters that can manage the nonlinear input as well as load discrepancy while staying in the desired operating range. This paper proposes a robust variable structure controller that ensures the stability of the converter over a wide operating range. This makes the converter suitable for energy sources with nonlinear voltage-current characteristics.

Power supply voltages in digital systems have been reduced considerably in recent years and often digital components requiring different voltages are present in the same board. This has increased the demand for multiple output power distribution systems with tight load regulation. In this paper, a detailed analysis and design of a multi-output fly back zero voltage switching (ZVS) quasi resonant converter (QRC) has been carried out.

This paper seeks to establish whether Interfresh Holding’s financials were relevant in signalling there being a probability of delisting prior to management’s decision at an Extra-Ordinary general meeting. The study makes use of the published financials from as far back as 2009 up to those published a year before the decision to delist. Key financial and performance indicators are analysed and the trend noted and contrasted to other findings in different economic set-ups.

Gesture detection using video and image processing is used for enabling the communication between the deaf, dumb & normal people. All the available systems are not portable and not affordable to poor people. This paper introduces new android application which will detect the Indian sign language via mobile camera and converts into corresponding text or voice output. This application reduces the major communication gap between the impaired and normal people. This application uses certain image processing techniques to compare the input with the already stored signs.

Malaria is not only a threat to pregnant women but to their newborn babies as well. It accounts for 1-3 million deaths yearly worldwide, with most of this burden occurring in children under 5 years of age in Sub-Saharan Africa. Around 90% of these deaths occur in Africa, mostly in young children. Malaria is Africa’s leading causes of under-five mortality (20%) and constitutes 10% of the continent’s overall disease burden. The treatment and control of malaria have become difficult with spread of drug-resistant strains of parasites leading to the discovery of sulfadoxine - prymethamine.

A model which describes the interaction of one predator with two prey species is considered. Due to large size, prey species have the ability of group defense. Therefore, the predator will be attracting toward that habitats where prey are less in number due to change in seasonal conditions. The stability analysis is carried out for a critical point of the system where all species co-exist. Using rate of conversion of the prey to predator as bifurcation parameter, conditions for a Hopf bifurcation to occur are derived.

The Ionization effects of charged particles produced in neutron interactions for Boron Neutron Capture Therapy (BNCT) are considered here using SRIM Monte Carlo Code. The estimated values of these effects in a Plexiglas acrylic phantom are shown to agree well with the available experimental values in high Boron concentration areas. As expected, the ionization effects from lithium and alpha particles are significant. In the low Boron areas, proton ionization makes an important contribution and its effect on healthy tissue should not be ignored.

This paper sets out to introduce a Size-biased Generalized Logarithmic Series Distribution (SBGLSD). An attempt is also made at obtaining the estimates of the parameters of SBGLSD by employing the method of moments and a proposed new method using the non-zero frequency of a variable up to a finite value. Comparison is also made among different estimation methods by means of Pearson’s Chi-square, Akaike Information Criterion (AIC) and Bayesian Information Criterion Techniques (BIC). It was observed that the proposed estimator gives better results in comparison to moment estimators.

Bulk density of a tea estate soil depends on the soil structure. It increases with soil depth due to the low content of total organic matter content. The principal objective of this work was to investigate the dependence of bulk density on texture, total organic matter content and macronutrients for the tea estate soil of Dibrugarh district. The relationship between some physical and chemical properties of soil such as, sand content, total organic matter content and macronutrients with bulk density were studied for sixty surface soil samples (0-15 cm) from ten tea estates.

One of the great successes of stellar evolution theory was the explanation of the origin of all elements. Fusion in the early universe produced hydrogen, helium, lithium, beryllium and boron, the first 5 elements in the periodic table. Other elements, from carbon to iron, were formed by fusion reactions in the cores of stars. The fusion process produces energy, which keeps the temperature of a stellar core high to keep the reaction rates high. Fusion of elements with mass numbers greater than 60 uses up more energy than is produced by the reaction.