Photoacoustic investigation of doped InP using open cell configuration

An open cell photoacoustic (PA) configuration has been employed to evaluate the thermal diffusivity of intrinsic InP as well as InP doped with tin and iron. Thermal diffusivity data have been evaluated from variation of phase of PA signal as a function of modulation frequency. In doped samples, we observe a reduced value for thermal diffusivity in comparison with intrinsic InP. We also observed that, while the phase of the PA signal varies linearly with the square root of chopping frequency for doped samples, the intrinsic material does not exhibit such behaviour in the experimental frequency range. These results have been interpreted in terms of the heat generation and phonon assisted heat diffusion mechanisms in semiconductors.

Self adhesion of short Kevlar fibre -thermoplastic polyurethane composite

The self adhesion behaviour of thermoplastic polyurethane (TPU) in itself and its composite with short Kevlar fibre with respect to contact time, temperature, pressure, and fibre loading has been studied. The adhesion strength showed two linear increments of different slopes with respect to the square root of time: with temperature and pressure of contact, the adhesion strength was improved. The maximum strength was obtained with 20 phr of short fibre in only one of the mating substrates in the peel test sample. The duration for wetting and diffusion was shifted to longer time intervals with fibres loaded in both the substrates.

Macrocyclic molecular square complex of zinc(II) self-assembled with a carbohydrazone ligand

A novel N4O coordination mode offers carbohydrazone ligands as a building block for interesting frameworks through self-assembly. Bridging mode of oxygen of bis(2-benzoylpyridine ketone) carbohydrazone (H2L) with metal centers facilitates the formation of the macrocyclic molecular square [Zn(HL)]4(BF4)4 · 10H2O, offers wide range of applications for carbohydrazones.

Dominant partial least square factors of consumer purchase behaviour of passenger cars

Globalization and liberalization, with the entry of many prominent foreign manufacturers, changed the automobile scenario in India, since early 1990’s. World Leaders in automobile manufacturing such as Ford, General Motors, Honda, Toyota, Suzuki, Hyundai, Renault, Mitsubishi, Benz, BMW, Volkswagen and Nissan set up their manufacturing units in India in joint venture with their Indian counterpart companies, by making use of the Foreign Direct Investment policy of the Government of India, These manufacturers started capturing the hearts of Indian car customers with their choice of technological and innovative product features, with quality and reliability. With the multiplicity of choices available to the Indian passenger car buyers, it drastically changed the way the car purchase scenario in India and particularly in the State of Kerala. This transformed the automobile scene from a sellers’ market to buyers’ market. Car customers started developing their own personal preferences and purchasing patterns, which were hitherto unknown in the Indian automobile segment. The main purpose of this paper is to develop a model with major variables, which influence the consumer purchase behaviour of passenger car owners in the State of Kerala. Though there are innumerable studies conducted in other countries, there are very few thesis and research work conducted to study the consumer behaviour of the passenger car industry in India and specifically in the State of Kerala. The results of the research contribute to the practical knowledge base of the automobile industry, specifically to the passenger car segment. It has also a great contributory value addition to the manufacturers and dealers for customizing their marketing plans in the State

Surface evolution of amorphous nanocolumns of Fe–Ni grown by oblique angle deposition

The growth of Fe–Ni based amorphous nanocolumns has been studied using atomic force microscopy. The root mean square roughness of the film surface increased with the deposition time but showed a little change at higher deposition time. It was found that the separation between the nanostructures increased sharply during the initial stages of growth and the change was less pronounced at higher deposition time. During the initial stages of the column growth, a roughening process due to self shadowing is dominant and, as the deposition time increases, a smoothening mechanism takes place due to the surface diffusion of adatoms

STUDIES ON TAXONOMY, DISTRIBUTION, ECOLOGY AND REPRODUCTIVE POTENTIAL OF ROTIFERS FROM SELECTED CENTRES IN COCHIN BACKWATER SYSTEM, KERALA

The studies were conducted in nine stations with varying ecological characteristics along Cochin backwaters and adjoining canals. Many workers opined that the distribution of rotifers is cosmopolitan. The significance of rotifers as first food for early larvae was indicated by Fujita. Aquaculture is a fast growing field in fisheries sector and it is gaining more importance as the fish landings and supply are getting irregular. A consistent supply of fish/shellfish can only be achieved through aquaculture. The success of any culture activity depends on the timely production of seeds of finfishes/shellfishes. The availability of wild seed is seasonal and erratic. So, a dependable source of seed of fishes and shellfishes is possible only through large scale production in hatchery. A successful seed production activity depends on the availability of a variety of suitable live feed organisms in sufficient quantities at the proper time for use in the larval stages. As the live feeds promote high growth rates, easy digestion, assimilation and the quality of not contaminating the culture water when compared to other artificial feeds, make the culture of live feed organisms the principal means of providing food for the larvae of finfishes and shellfishes. Rotifers are considered to be an excellent and indispensable food for larvae of many finfishes and crustaceans. It (1960) was the first to culture Brachionus plicatilis for feeding marine fish larvae, and now it is being extensively used as live feed in hatcheries all over the world. They are a group of microscopic organisms coming under the Phylum Rotifera which comprises of about 2000 species. Their slow swimming habits, ability to tolerate a wide range of salinities, parthenogenetic mode of reproduction and ability to get enriched easily, make rotifers an ideal live feed organism. The major factors such as temperature, salinity and food that influence the reproductive potential and thereby the population size of rotifer, Salinity is one of the most important aspect influencing the reproductive rate of rotifers. The feed type and feed concentration play a vital role in influencing the reproductive rate of rotifers. For culture of rotifers, the commonly used micro algae belong to Chlorella, Nannochloropsis, Isochrysis and Tetraselmis. While some studies have suggested that, algal diet has little effect on reproductive rates in 1979 while using the rotifer, Brachionus plicatilis as feed for the larvae of red sea bream, Pagrus major. It is generally accepted that rotifers play a pivotal role in the successful rearing of marine fish larvae.

Alkylation of Benzene with I-Octene over Titania Pillared Monmorillonite

Linear alkylbenzene sulfonic acid, the largest-volume synthetic surfactant, in addition to its excellent performance , is important due to its biodegradable environmental friendliness, as it has a straight chain and is prepared by the sulphonation of linear alkylbenzenes (LAB). To ensure environmental protection, the commercial benzene alkylation catalysts HF or AICI3 are replaced and we have developed a clean LAB production process using a pillared clay catalyst capable of not only replacing the conventional homogeneous catalyst, but also having high selectivity for the best biodegradable 2-phenyl LAB isomer .Pillared clay catalysts having high Bronsted acidity show efficient conversion in gas phase alkylation of benzene with 1-octene with a good 2-phenyl octane selectivity.

Use of mirage effect for the detection of phase transitions in solids

The phenomenon of mirage effect suffered by a He-Ne laser beam has been utilized to detect phase transitions in solids. It has been observed that anomalous fluctuations of large amplitude occur in the signal level near the transition temperature. The mean square value of the fluctuation is found to exhibit a well-defined peak at this point. Results of measurements made in the case of crystals of TGS ((NH2CH2COOH)3.H2SO4) and a ceramic sample (BaTiO3) are given to illustrate this technique.

Present status of coral erosion in Lakshadweep with special reference to Minicoy

Coral Reefs are marine, biogenic, wave resistant carbonate structures, formed of the skeletal remains of hermatypic, or reef building organisms. The main reef builders are calcifying Rhodophytes, molluscs, sponges, polychaetes and Cnidarians. Among them, scleractinian corals and hydrocorallians are by far the most important contributors to the formation of reefs. Coral reefs cover approximately 600 thousand square kilometers of the earth's surface (Crossland fl a_1., 1991) which is about 2x106 square kilometres of tropical oceans.

Industrial Growth in Madhya Pradesh: Structure and Economic Backwardness

It examine the aspects of Madhya Pradesh’s industrial structure which throw light on the development, viability and the efficiency of not only the over all industrial sector but also some of the selected industries of the state. The major objectives of are to examine the nature and characteristics of economic backwardness in Madhya Pradesh in an inter-state comparative framework and to analyse the pace and pattern of industrial growth in Madhya Pradesh against the backdrop of liberalization. To explore the industrial structure of Madhya Pradesh using the major structural ratios and industry mix. This study has underlined some structural as well as region specific constraints to the accelerated growth of the manufacturing industry in Madhya Pradesh. The industrial structure of Madhya Pradesh is concentrated and lop-sided. This is evidenced by the dominancy of single industry, basic metal and alloys. A diversified industrial structure is essential for promoting interdependent growth of the manufacturing industry based on the inter-industry linkages and agglomeration. The thesis gives a broad spectrum of regional disparities in development and evidence for Madhya Pradesh’s backwardness also portrayed and reflects the changing industrial structure of the state.

INDIAN AND ANTARCTIC BRYOZOANS - TAXONOMY AND OBSERVATIONS ON TOXICOLOGY

This thesis embodies findings on a taxonomical investigation of a group of lower marine invertebrates belonging to the category coelomata. Bryozoans are well known both in fossil and recent taxonomical history. They comprise of about 5,000 living and 16000 fossil species. Bryozoans are well known for their taxonomic abundance and structural diversity,representing the various ecological niches ranging from the intertidal to the abyssal benthic. At a time when global marine biological diversity has become a concern of not only to the scientists but also to the policy makers,an understanding of species diversity and abundance are cardinal aspects of biological studies. Geological time scales which is known that by Pre-Cambrian, marine invertebrate diversity reach the maximum and this diversity has become more comprehensive as time advanced. Taxonomists a vanishing species of scientists have become more concerned in discerning patterns of species diversity. The basic tool for this is identification fo animals. with this idea in mind a detailed study of taxonomy of bryozoan was undertaken . The major part of this thesis is devoted to describe various species of bryozoans with detailed description and ecotypical variations.The pattern of distribution and abundance which are important aspects of animal groups have also been documented. Possible effects of heavy metal contamination on the tolerance and growth of bryozoans, a few species of which have been eliminated from the chronically polluted areas of Cochin backwaters have also been documented.