Experimental investigations on forming limit diagram of ultra thin SS 304 steel : effect of circular grid size, sheet orientation, punch size and deformation speed

In the present work, SS 304 sheet of 200 μm thickness was used to experimentally evaluate the forming limit diagram (FLD). In this context, a sub-size limiting dome height (LDH) test setup was developed to deform rectangular specimens of different widths using a 30 mm hemispherical punch. Further, effect of various parameters such as change in circular grid size, stretching direction with respect to rolling direction of the sheet, punch size and deformation speed on limiting strains was investigated. It was observed that there was marginal change in limiting strains due to the change of punch diameter from 30 mm to 50 mm. The FLD0 level changed approximately 7.5% and 6.8% with the change in punch diameter and stretching direction respectively. It was also found that the FLD0 value increased by 15% with change in circular grid diameter from 2.5 mm to 2.0 mm. However, a negligible change in the limiting strains was noted when the grid diameter was further reduced to 1.0 mm. There was negligible change in the FLD0 level with increase in punch speed from 4 mm/min to 100 mm/min, but approximately 13% decrease was found when the punch speed was further increased to 400 mm/min. Moreover, the LDH, strain distribution and failure strains were also analyzed in context of formability

Prediction of Shot Start Pressure for Rifled Gun System

Determination of short start pressure (SSP) for gun system has always been of paramount interest for gun designers. In this paper, a generalised model has been developed for theoretical prediction of SSP for rifled gun system using dimensional analysis approach. For this, parameters affecting the SSP of the gun like rifling dimensions, driving band dimensions, material properties of driving band, projectile mass and diameter are taken into consideration. For a particular case of large caliber rifled gun system, the model is established using linear relations among dimensionless groups of parameters. The model has been validated by data available from the open literature

CDM as a Solution for the Present World Energy Problems (An Overview with Respect to the Building and Construction Sector)

One of the important responses of Kyoto Protocol towards mitigation of global warming is the Clean Development Mechanism (CDM), which has garnered large emphasis amidst the global carbon market in terms of Certified Emission Reductions (CERs). While CDM aims to achieve sustainable development in the energy production and its consumption in developing countries, the results achieved through its implementation are still uncertain. Presently, the domestic and commercial buildings are responsible for more than one third of the total conventional energy use and associated greenhouse gas emissions. The Inter-governmental Panel on Climate Change (IPCC) stated that, the building sector has the largest potential for significantly reducing greenhouse gas emissions. This paper envisages the important aspects such as, the non-inclusion of construction sector projects in CDM and its reasons, the role of energy efficiency buildings in the energy conservation arena and the new challenges being faced, while implementing the CDM portfolio in building energy sector

In silico and in vitro analysis of quorum quenching active phytochemicals from the ethanolic extract of medicinal plants against quorum sensing mediated virulence factors of Acinetobacter baumannii

Inhibition of quorum sensing called quorum quenching (QQ) is now extensively utilized in the prevention of bacterial infections. In the present study, in silico and in vitro analysis of quorum quenching (QQ) or anti-Quorum sensing (QS) activity of ethanolic extract of medicinal plants against QS mediated virulence factors of human pathogenic bacteria Acinetobacter baumannii has been investigated. The effect of plant extracts on QS by acyl homoserine lactone (AHL) has been carried out by quantification of secreted AHL by high-pressure liquid chromatography (HPLC). Measurement of QQ activity was determined by maximum inhibition of virulence factors and AHL production which was recorded in E. globules and A. indica extracts. In silico analysis was studied with possible bioactive compounds in the ethanolic extract of respective plant material that were characterized by gas chromatography equipped with mass spectroscopy (GCMS) against the enzyme responsible for the production of signaling molecule which mediates QS AHL synthase. Distinct reduction of all the QS-mediated virulence factors was recorded in the E. globules and A. indica. Among the different bioactive compounds, the ethanolic leaf extract of E. globules of GCMS analyzed compound, Hexadeconoic acid, 1-(hydroxymethyl), 1, 2-ethannediyl ester interacted with 1KZF protein (AHL synthase) and showed binding energy of −11.2 kcal/mol to MET 42 and TYR 54. Phytochemicals mediated inhibition of AHL synthase activity which was responsible for AHL production would suggest the possible utilization of plant extracts as an antibacterial agent to fight against disease-causing pathogenic bacteria

A Meta Model for Domestic Energy Consumption

Prediction of energy consumption particularly in micro level is of vital importance in terms of energy planning and also implementation of any Clean Development Mechanism (CDM) activities that has become the order of the world today. It may be difficult to model household energy consumption using conventional methods such as time series forecasting due to many influencing factors. This paper presents a step wise regression model for forecasting domestic energy consumption based on micro level household survey data collected from Kerala, a state in southern part of India. The analysis of the data reveals significant influence of socio-economic, demographic, geographic, and family attributes upon total household energy requirements. While a wide variation in the pattern of energy requirements across the domestic sector belonging to different expenditure classes, per capita income level can be identified as the most important explanatory variable influencing variation in energy requirements. The models developed also demonstrates the influence of per capita land area, residential area among the higher income group while average age and literacy forms significant variables among the lower income group. Keywords: Meta Model; Consumption Pattern; Domestic Energy Requirement JEL classifications: E2; Q

Noctiluca scintillans bloom and measures to protect marine hatcheries

During the third week of November 2022, bloom of Noctiluca scintillans (Macartney, 1810) was observed in multiple locations along the coastal waters off Thiruvananthapuram. Noctiluca bloom is commonly called as 'sea sparkles, as it produces blue bioluminescence at nigh

Understanding the errors of SHAPE-directed RNA structure modeling

Single-nucleotide-resolution chemical mapping for structured RNA is being rapidly advanced by new chemistries, faster readouts, and coupling to computational algorithms. Recent tests have shown that selective 2'-hydroxyl acylation by primer extension (SHAPE) can give near-zero error rates (0-2%) in modeling the helices of RNA secondary structure. Here, we benchmark the method using six molecules for which crystallographic data are available: tRNA(phe) and 5S rRNA from Escherichia coli, the P4-P6 domain of the Tetrahymena group I ribozyme, and ligand-bound domains from riboswitches for adenine, cyclic di-GMP, and glycine. SHAPE-directed modeling of these highly structured RNAs gave an overall false negative rate (FNR) of 17% and a false discovery rate (FDR) of 21%, with at least one helix prediction error in five of the six cases. Extensive variations of data processing, normalization, and modeling parameters did not significantly mitigate modeling errors. Only one varation, filtering out data collected with deoxyinosine triphosphate during primer extension, gave a modest improvement (FNR = 12%, and FDR = 14%). The residual structure modeling errors are explained by the insufficient information content of these RNAs' SHAPE data, as evaluated by a nonparametric bootstrapping analysis. Beyond these benchmark cases, bootstrapping suggests a low level of confidence (<50%) in the majority of helices in a previously proposed SHAPE-directed model for the HIV-1 RNA genome. Thus, SHAPE-directed RNA modeling is not always unambiguous, and helix-by-helix confidence estimates, as described herein, may be critical for interpreting results from this powerful methodology.Comment: Biochemistry, Article ASAP (Aug. 15, 2011

A microbial supply chain for production of the anti-cancer drug vinblastine

International audienceAbstract Monoterpene indole alkaloids (MIAs) are a diverse family of complex plant secondary metabolites with many medicinal properties, including the essential anti-cancer therapeutics vinblastine and vincristine 1 . As MIAs are difficult to chemically synthesize, the world’s supply chain for vinblastine relies on low-yielding extraction and purification of the precursors vindoline and catharanthine from the plant Catharanthus roseus , which is then followed by simple in vitro chemical coupling and reduction to form vinblastine at an industrial scale 2,3 . Here, we demonstrate the de novo microbial biosynthesis of vindoline and catharanthine using a highly engineered yeast, and in vitro chemical coupling to vinblastine. The study showcases a very long biosynthetic pathway refactored into a microbial cell factory, including 30 enzymatic steps beyond the yeast native metabolites geranyl pyrophosphate and tryptophan to catharanthine and vindoline. In total, 56 genetic edits were performed, including expression of 34 heterologous genes from plants, as well as deletions, knock-downs and overexpression of ten yeast genes to improve precursor supplies towards de novo production of catharanthine and vindoline, from which semisynthesis to vinblastine occurs. As the vinblastine pathway is one of the longest MIA biosynthetic pathways, this study positions yeast as a scalable platform to produce more than 3,000 natural MIAs and a virtually infinite number of new-to-nature analogues

Optimizing transportation of fertilized eggs and yolk sac larvae of Silver Pompano (Trachinotus blochii)

Fish seed transport is one of the significant activities in fish farming. The study optimised the packing density of eggs and yolk-sac larvae of Trachinotus blochii in closed plastic bags without using any tranquillizers. The post-shipment survival after railway shipment to varying distances was analyzed to optimize the stocking density. Six litres of seawater (of 34 ppt salinity) in a 32’ x 16.5’ polythene bag with 8-10 ppm oxygen concentration is used to transport various packing densities of egg and yolk-sac larvae. The results indicated that packing density and duration significantly influence survival rate during the transportation of fertilized yolk sac larvae of silver pompano. The optimum stocking density obtained for fertilized eggs (0 dph unhatched larvae) and 1st dph yolk sac larvae are 4100 ± 65.46 /L and 901.5 ± 33.58/L, respectively

Validation of Landsat Thematic Mapper-derived phytoplankton pigments through synchronous surface measurements: area off Calicut to Azhikal in the Arabian Sea

This paper deals with an estimation of phytoplankton pigments from Landsat Thematic Mapper (Tivi) data after removal of atmospheric effect. The pigments derived from Landsat TIV1 data of October, 1986 and March, 1987 have been compared with corresponding surface values measured during ship cruise programmes synchronous to satellite overpass. In-water algorithm for Landsat TM bands was developed from the sea data collected off Quilon to Malpe In the Arabian sea at different periods of the year. A uniform bias towards underestimation of pigments has been observed in the case of October data and an appropriate modification In the pigment algorithm for Landsat TM has bnen suggested