ISRO Polyol - The Versatile Binder for Composite Solid Propellants for Launch Vehicles and Missiles

A family of propellants based on a low cost hydroxy terminated binder has been developed and proved in large size motors. It can meet the requirements of Apogee motors as well as large boosters. The system offers advantages comparable with HTPB propellants in terms of high ballistic performance, stringent mechanical properties, ease and reliability of cure even at ambient conditions and high storage stability. The near-Newtonian flow behaviour, simplicity and processing characteristics of this saturated binder propellant are particularly note-worthy

Seaweed and their importance

Agar agar and algin serve as stabilizers, emulsifiers, thickeners, and gelling agents

Marine Algal Flora From Selected Centres Along The Madras Coast

A survey was made on the marine algae occurring at Pulicat, Kovalam, Muthukadu andMahabalipuram along the Madras coast. A total of 22 species were collected of which six species belonged to Chlorophyta, three to Phaeophyta, 10 to Rhodophyta and three to Cyanophyta. Out of the 22 species, 16 are recorded for the first time along the Madras coas

Seaweed recipes and other practical uses of Seaweeds

Seaweeds (a plant group of the sea) in botanical terms "Algae" form an important food item in many countries of the East as well as West. In China, marine algae bears the name sea-vegetable and it is not uncommon for coastal inhabitants of Japan, Malaya, China and Phillippines to be seen on the seashore during low tide collecting these sea-vegetables. Korea and Japan are the two ceuntries where algae are farmed but only in Japan extensive seaweed cultivation is done

Growth, Reproduction and Liberation of Oospores in Turbinaria ornata (Turner) J. Agardh

Young plants of T. ornata appeared in April and grew to maximum size during October to December. Plants were mostly unbranched between February and June and thereafter branching started reaching maximum during September to November. Reproductive plants were found throughout the year with a peak spore output in November (33810 oospores/plant). There was no periodicity in the liberation of oospores. T. ornate may be harvested during the peak growth period from October to December for the manufacture of alginic acid

Alterations in sperm characteristics of follicle-stimulating hormone (FSH)-immunized men are similar to those of FSH-deprived infertile male bonnet monkeys

The quality of sperm ejaculated by bonnet monkeys and normal, healthy proven fertile volunteer men, both actively immunized with ovine follicle-stimulating hormone (oFSH), was examined at different times of study for chromatin packaging and acrosomal glycoprotein concentration by flow cytometry. Susceptibility of sperm nuclear DNA to dithiothreitol (DTT)-induced decondensation, as measured by ethidium bromide binding, was markedly high compared with values at day 0 in men and monkeys during periods when FSH antibody titer was high. Sperm chromatin structure assay yields alphat values, which is another index of chromatin packaging. Higher alphat values, signifying poor packaging, occurred in both species following immunization with heterologous pituitary FSH. The binding of fluorosceinated pisum sativum agglutinin (PSA-FITC) to acrosome of sperm of monkeys and men was significantly low, compared with values at day 0 (control) during periods when cross-reactive FSH antibody titer was high and endogenous FSH was not detectable. Blockade of FSH function in monkeys by active immunization with a recombinant oFSH receptor protein corresponding to a naturally occurring messenger RNA (mRNA) also resulted in production of sperm with similar defects in chromatin packaging and reduced acrosomal glycoprotein concentration. Thus, it appears that in monkeys and men, lack of FSH signaling results in production of sperm that exhibit defective chromatin packaging and reduction in acrosomal glycoprotein content. These characteristics are similar to that exhibited by sperm of some class of infertile men. Interestingly, these alterations in sperm quality occur well ahead of decreased sperm counts in the ejaculate

Seaweed culture in India-an appraisal

In recent years there has been a steady increase in the demand for naturally occuring seaweeds as a result of many seaweed based industries coming up. In order to meet the raw material requirement of these industries attempts have been made in this country to develop suitable seaweed farming techniques by some Institutes notably the CMFRI at its Mandepam. Regional Centre and CSMCRI at its field centre, Mandapam. Experimental culture of economically important seaweeds such as Gracllaria edulis, Gelidiella acerosa and other species was undertaken since 1972 at Mandapam- in these experiments production rates ranging from 3 to 8 times the initial wet weight were obtained. The techniques of seaweed culture, the favourable seasons optimum duration of culture period and the influence of environmental parameters are discussed in this account with notes on economics of seaweed culture. General information on the seaweed resources slong our coasts, their potential for exploitation and culture are also highlighted

Immunobiology of a synthetic luteinizing hormone receptor peptide 21-41

Immunization of adult male rabbits with a synthetic luteinizing hormone-receptor peptide (LH-RP; representing amino-acids 21-41 of the extracellular domain of the rat LH receptor) resulted in production of high-titer antibodies capable of interacting with particulate and cell-based LH receptors. The antibody produced was able to inhibit binding of 125I-labeled human chorionic gonadotropin (hCG) to a particulate sheep luteal LH receptor preparation by 40%-50%. Maximal inhibitory activity was correlated with high antibody titer. Immunocytometry revealed that the antibody could directly bind to cells having LH receptors, such as rat granulosa and Leydig cells. The antibodies recognized a 77-kilodalton membrane protein in Western blots of mouse testicular extracts. Interaction of endogenous Leydig cell LH receptor with the LH-RP antibody resulted in both hormone agonist and antagonistic activities. The hormone-mimicking activity (increase in serum testosterone over control) was confined only to the early phase of immunization when the antibody titer was low. Blockade of LH receptor during the later part of immunization resulted in a significant reduction in serum testosterone over controls and inhibition of spermatogenesis. DNA flow cytometry showed that a specific and significant inhibition of meiosis (transformation of primary spermatocytes to round and elongated spermatids P < .01) and spermiogenesis (transformation of round spermatids to elongated spermatids P < .0001) occurred following blockade of LH function

Testing compliance of drug taking-A simple bed side method

Assessment of compliance in drug taking is a problem in a crowded Outpatient Department. Using riboflavin as a urinary marker is a simple and rational method. Identifying riboflavin in the urine by fluorescence on exposure to ultraviolet (UV) rays or torch light is being used in medical practice but not extensively. In this study, the validity and reliability of these methods were assessed. The sensitivity and specificity of this test by UV method was 86% and 82% for Reader I (medical person) and 82% and 94% for Reader II (paramedical person). For Reader 1, the accuracy of reading by UV lamp was the same as torch light (85%) whereas for Reader II the accuracy was better with UV lamp (87%) than with torch (79%). In reading the fluorescence by UV lamp the crude agreement between the 2 readers was 82% and chance corrected agreement was 64%. UV lamp method appears to be a reliable way of assessing compliance both by medical and paramedical persons whereas torch method appears to be more reliable when used by a medical person than by a paramedical person

Thermal Decomposition of Ammonium Perchlorate in thePresence of Nanosized Ferric Oxide

The catalytic effect of two different sizes of a-Fe2O3 nanoparticles synthesised using an electrochemicalmethod was investigated on the thermal decomposition of ammonium perchlorate (AP) using differentialscanning calorimetry as a function of catalyst concentration.  The nanosized ferric oxide particles exhibitedmore of a catalytic effect on the thermal decomposition of AP than commercial Fe2O3  particles. A loweringof the high-temperature decomposition of AP by 59 oC was observed after mixing with 2 Wt per cent ofa-Fe2O3  particles with the very fine size of 3.5 nm. The mixture produced a high heat release of 4.574 kJ/g compared to 0.834 kJ/g of pure AP. The kinetic parameters were evaluated using Kissinger method. Thedecrease in the activation energy and increase in rate constant confirmed the catalytic activity of thesenanoparticles.Defence Science Journal, 2008, 58(6), pp.721-727, DOI:http://dx.doi.org/10.14429/dsj.58.169