Cosmological horizon entropy and generalised second law for flat Friedmann Universe

We discuss the generalized second law (GSL) and the constraints imposed by it for two types of Friedmann universes. The first one is the Friedmann universe with radiation and a positive cosmological constant, and the second one consists of non-relativistic matter and a positive cosmological constant. The time evolution of the event horizon entropy and the entropy of the contents within the horizon are analyses in an analytical way by obtaining the Hubble parameter. It is shown that the GSL constraint the temperature of both the radiation and matter of the Friedmann universe. It is also shown that, even though the net entropy of the radiation (or matter) is decreasing at sufficiently large times as the universe expand, it exhibit an increase during the early times when universe is decelerating. That is the entropy of the radiation within the comoving volume is decreasing only when the universe has got an event horizon.Comment: 15 pages, 9 figure

Edible Oyster Farming in India

The oysters are highly esteemed sea food and considered a delicacy in USA, Europe, Japan etc. In India there is a growing demand for oyster meat in some parts of the country. It is said that ‘oyster’ is scientifically the best known marine animal. It is one of the most widely cultivated species. As early as the first century BC the Romans were the first to develop simple methods of collecting oyster seeds and growing them for food. The Japanese developed ‘Habitat culture technique.i.e. Culture in nets fixed to bamboo poles during the seventeenth century and at the turn of the 20th century they evolved off bottom culture, especially hanging methods. These methods yielded good results and were adopted by majority of oyster farmers of Japan as the environmental conditions of the coastal areas were highly favorable for practicing these methods. Until recently, oyster farming has been considered as a traditional practice followed only in the temperate countries. The awareness about the vast potentialities for development of oyster farming in tropics is recent. Serious efforts are now being directed in its development under tropical conditions

Acoustic emission signal ‘peak amplitude-distribution’ analysis related to concrete fracture under uniaxial compression

Acoustic emissions (AE) released during the compressive fracture of cementitious materials have been subjected to analysis using ‘AE based b-value’ to study the fracture process. Identification of the ‘AE sources locations’ in three dimension is not always possible. With a minimum number of AE sensors mounted on the test specimen and by using the AE based b-value analysis, it is possible to study fracture process and the damage status in solids. The b-value of AE is calculated using the Gutenberg–Richter empirical relationship (G-R law), which is available in seismology. The details related to original G-R relation and it’s suitability for AE testing were discussed. In this article it has been tried to look into the variations of the AE based b-value in cementitious test specimens prepared with different cementitious mixture proportions. Effect of (i) coarse aggregate size in cementitious materials (ii) loading rate during compressive fracture process (iii) age of concrete on b-value variation were discussed. The trend of variation in AE based b-value during fracture process in concrete and mortar was different. It was observed that when the compression toughness of the cementitious material increases, higher b-values were observed. When the loading rate was high, quick cracking occurred and lower b-values were observed. As the coarse aggregate size in the cementitious material increases, the cumulative AE energy was higher. The reason may be due to the compression toughness of the cementitious material. The AE based b-value is useful to identify the different stages of compressive fracture process in solids

Antagonistic Activity of Probiotic Organism Against Vibrio cholerae and Cryptococcus neoformans

The microbes are useful in many ways in the modern world. Probiotics one of them, which refers to, acid adherence bacteria in the intestinal cells, are able to survive at low pH and produce large amount of lactic acid. The present investigation deals with the antagonistic activity of Lactobacillus acidophilus organism against pathogens. The organism was isolated from the curd sample. Identification of bacteria was done by various biochemical testing. The present study revealed that L. acidophilus inhibits Vibrio cholerae more efficiently than Streptococcus pneumoniae and Shigella dysentriae. When L. acidophilus and V. cholerae were grown together, L. acidophilus dominated the growth and competitively inhibited the growth of V. cholerae. L. acidophilus was also found to inhibit Cryptococcus neoformans

Ecotoxicological Studies on the Bioaccumulation of the Heavy metals in the Vellore population,TamilNadu, India

The study was totally aimed to know the extent of bioaccumulation through the plants from the sediments. Total heavy metals concentration (chromium, lead, zinc, nickel and cadmium) were undertaken in the food composites collected from Puliyanthangal village near Ranipet of Vellore district, Tamilnadu, India. There are around 240 tanneries in these areas, besides number of  ceramic, refractory, boiler auxiliaries plant and chromium chemical factories. Since the ground water was heavily contaminated with heavy metals, studies were carried out to know if there was transfer of heavy metals in the food chain. Drinking water samples, sediment samples as well as food samples were  collected and analysed for Chromium, Lead, Nickel, Zinc and Cadmium levels. The Environmental risk assessment was undertaken in the foodchain for all the above metals through water, sediment and through the grains and the crops grown in that area. Bioaccumulation factor was calculated with respect to the above parameters and it was concluded that the heavy metals were found to be concentrated through the various levels of food chain but not  biomagnified through the food chain

Plastic to Petrol

Perinjanam is a coastal village in Thrissur district in the state of Kerala, India. It is one of the smallest villages in Kerala. Perinjanam Panchayath has been recognized as the first Panchayath in India with ‘ISO 9001 2015’ certification. National Accreditation Board of Certification Body (NABCB) has conducted valuation in two steps and was found that the Panchayath has fulfilled the criteria suggested by Quality Council of India. The Science Centre was established in 2006 under the Charitable Society Act with an aim to undertake scientific experiments. Several Teachers and students are undertaking science related activities in 5 buildings spread over 70 cents of land of Kodungalloor Municipality. Mr. V. S. Sreejith, is the Director of Science Centre, has designed a plant and the perinjanam Panchayath has developed the prototype of a pyrolysis plant in which plastic waste is burnt and distilled to make petrol and other by products. This is a part of its endevour to find a low-cost and pollution free technology for processing non biodegradable waste