I.C. Engine emissions with varied proportions of mixtures of petrol, diesel, bio-diesel and other organic fuels

The numbers of Internal Combustion engines are increasing day by day. The undesirable emissions generated in the combustion process in IC engine pollute the environment which contributes to global swarming, acid rain, smog, respiratory and other health problems. The major causes of these emissions are non-stoichiometric combustion, dissociation of Nitrogen, and impurities in the fuel and air. The emissions of major concern to health are hydrocarbons (HC), carbon monoxide (CO), Oxides of Nitrogen (NOx), Sulphur and solid carbon particulates. Ideally, engines and fuel systems could be developed in such a way that very few harmful emissions would be generated, and these could be exhausted to the surroundings without a major impact on the environment. With present technology this is not possible, and hence after-treatment of the exhaust gases to reduce emissions is very important. This consists mainly of the use of thermal or catalytic converters and particulate traps.&nbsp

Low-energy quenching of positronium by helium

Very low-energy scattering of orthopositronium by helium has been investigated for simultaneous study of elastic cross section and pick-off quenching rate using a model exchange potential. The present calculational scheme, while agrees with the measured cross section of Skalsey et al, reproduces successfully the parameter ^ 1Z_{\makebox{eff}}, the effective number of electrons per atom in a singlet state relative to the positron. Together with the fact that this model potential also leads to an agreement with measured medium energy cross sections of this system, this study seems to resolve the long-standing discrepancy at low energies among different theoretical calculations and experimental measurements.Comment: 4 latex pages, 3 postscript figure

Meiotic sex chromosome cohesion and autosomal synapsis are supported by Esco2.

In mitotic cells, establishment of sister chromatid cohesion requires acetylation of the cohesin subunit SMC3 (acSMC3) by ESCO1 and/or ESCO2. Meiotic cohesin plays additional but poorly understood roles in the formation of chromosome axial elements (AEs) and synaptonemal complexes. Here, we show that levels of ESCO2, acSMC3, and the pro-cohesion factor sororin increase on meiotic chromosomes as homologs synapse. These proteins are less abundant on the largely unsynapsed sex chromosomes, whose sister chromatid cohesion appears weaker throughout the meiotic prophase. Using three distinct conditional Esco2 knockout mouse strains, we demonstrate that ESCO2 is essential for male gametogenesis. Partial depletion of ESCO2 in prophase I spermatocytes delays chromosome synapsis and further weakens cohesion along sex chromosomes, which show extensive separation of AEs into single chromatids. Unsynapsed regions of autosomes are associated with the sex chromatin and also display split AEs. This study provides the first evidence for a specific role of ESCO2 in mammalian meiosis, identifies a particular ESCO2 dependence of sex chromosome cohesion and suggests support of autosomal synapsis by acSMC3-stabilized cohesion

Grain yield of aerobic rice as influenced by seed rate and row spacing in aerobic situation under changed climate

Aerobic rice system is the method of cultivation, where the rice crop is established by direct seeding in un-puddle field. The grain yield of aerobic rice in aerobic situation realized by the farmers is still lower. Among many factors, seed rate and row spacing influence the grain yield of aerobic rice crop. The present investigation was carriedout to study the influence of seed rates and row spacing on grain yield of aerobic rice in aerobic situation, and field experiment was conducted at Rice Research Station, Bankura, West Bengal, India during kharif season of 2011 and 2012. The experimental results exhibited that the highest grain yield (3.40, 3.49 and 3.42 t ha-1 during kharif 2011, kharif 2012 and in pooled value, respectively) was recorded from treatment S2, where seed rate was 30 kg ha-1. Among the different row spacing, the maximum grain yield of 3.47, 3.45 and 3.46 t ha-1 during kharif season of 2011 and 2012 and on pooled basis was obtained with the treatment R1 i.e. 20 cm row spacing. The treatment combination of S2 (seed rate @ 30 kg ha-1) and R1 (20 cm row spacing) recorded the highest grain yield (4.01 t ha-1) of aerobic rice. It was established that the seed rate @ 30 kg ha-1 and 20 cm row spacing was promising for realizing best grain yield of aerobic rice in aerobic condition. It is an important eco-safety tool for tackling the climate change scenario