301 research outputs found

    The dynamic indentation behavior of steel at large depths of penetration

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    The objective of the present study is to investigate the dynamic indentation behavior of steel plate material when impacted by ogive-shaped projectiles and in particular under indentation conditions involving large depths of penetration (i.e., depth of penetration greater than projectile radius). Toward the above purpose, dynamic indentation of steel plates of thickness 20, 40, and 80 mm have been carried out using projectiles of diameter 6.2 and 20 mm, and over a range of impact velocities so as to attain depths of penetration in the range 1.4 to 3.6 times the projectile radius. The results indicate that the dynamic hardness, the plastic zone size, specific energy consumed in plastic deformation within the plastic zone, and the average plastic strain within the plastic zone increases continuously with increasing values of depth of penetration normalized by projectile radius. Certain subtle differences regarding the nature of plastic deformation between indentation at large and shallow depths of penetration are presented. However, on a macroscopic scale, the indentation mechanisms and processes are broadly similar and show continuity in terms of behavior across the whole penetration depth range

    Effect of Clamping Rigidity of the Armour on Ballistic Performance

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    Influence of the manner in which the armour plates are held during their ballistic testing on the armour performance, has been evaluated. One armour plate was clamped rigidly to the test stand while a second plate of identical composition, hardness, and dimensions was hung loosely from the target holder. Both these plates were impacted with the same type of projectiles and over the same impact velocity range. The nature of ballistic damage evaluated indicates that the manner in which the armour is held during ballistic testing has a negligible influence on its performance at least when the mass of the plate is substantially higher than that of the projectile

    Comparative study of Growing/ Immobilized biomass verses resting biomass of A.lentulus for the effect of pH on Cu 2+ metal removal

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    ABSTRACT Biosorption of Cu (II) ions from aqueous solution was studied using A.lentulus immobilized by sodium alginate (4.0 g) and gelatin (1.0 g) prepared into a 0.05M CaCl 2 solution under constant stirring. Uptake of metal was very fast at 25 min initially and equilibrium was attained within 125 min. Higher Cu(II) uptake was observed by selected biomass (4.0g/l) immobilized in calcium chloride at 35 o C, 180 rpm when initial Cu 2+ ions concentration was 100mg/l. The optimum condition of pH, biomass concentration and heavy metal concentration were determine for microbial growth on biosorbents and correlated with heavy metal removal. The observed condition was applied for the biosorption process in immobilized and dead fungal cells. The biosorption of immobilized cells of A. lentulus was 96.6% of Cu whereas the dead cells of A. lentulus were 84%

    Phenotypic profiling of lentil (Lens culinaris Medikus) accessions enabled identification of promising lines for use in breeding for high yield, early flowering and desirable traits

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    In the face of climate change, developing resilient crops is crucial for global food security in the 21st century to feed a growing population. Lentil (Lens culinaris Medikus) plays a vital role in ensuring global food and nutritional security. Traits like early flowering enable the crop to mature faster, thereby shortening the growing window and reducing yield losses caused by moisture and heat stresses during the reproductive phase. However, issues like limited genetic diversity in this trait remain unaddressed. To address this gap, our study aims to comprehensively assess genetic variability and trait associations in 158 lentil accessions. In the present study, we observed significant variations for days to 50% flowering (67–90 days), days to maturity (109–122 days) and 100 seed weight (1.69–2.68 g) throughout a period of two consecutive years (2020–2021 and 2021–2022). The observed variability in these traits offers a valuable avenue for the improvement of lentil yield through targeted selection and hybridization. Additionally, correlation analysis showed negative correlation between days to 50% flowering and grain yield per plant, while plant height had a significant (P < 0.01) positive correlation with all traits except yield per plant. Furthermore, we identified specific germplasm with exceptional traits that hold significant potential for future breeding programmes. The genotypes EC 223197-A and EC 267696 were identified for early flowering with high yield, and other genotypes that were identified for various traits would serve as breeding material for the introgression of these traits into elite cultivars

    Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study

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    In recent decades, the possibility that use of mobile communicating devices, particularly wireless (mobile and cordless) phones, may increase brain tumour risk, has been a concern, particularly given the considerable increase in their use by young people. MOBI-Kids, a 14-country (Australia, Austria, Canada, France, Germany, Greece, India, Israel, Italy, Japan, Korea, the Netherlands, New Zealand, Spain) case-control study, was conducted to evaluate whether wireless phone use (and particularly resulting exposure to radiofrequency (RF) and extremely low frequency (ELF) electromagnetic fields (EMF)) increases risk of brain tumours in young people. Between 2010 and 2015, the study recruited 899 people with brain tumours aged 10 to 24 years old and 1,910 controls (operated for appendicitis) matched to the cases on date of diagnosis, study region and age. Participation rates were 72% for cases and 54% for controls. The mean ages of cases and controls were 16.5 and 16.6 years, respectively; 57% were males. The vast majority of study participants were wireless phones users, even in the youngest age group, and the study included substantial numbers of long-term (over 10 years) users: 22% overall, 51% in the 20-24-year-olds. Most tumours were of the neuroepithelial type (NBT; n = 671), mainly glioma. The odds ratios (OR) of NBT appeared to decrease with increasing time since start of use of wireless phones, cumulative number of calls and cumulative call time, particularly in the 15-19 years old age group. A decreasing trend in ORs was also observed with increasing estimated cumulative RF specific energy and ELF induced current density at the location of the tumour. Further analyses suggest that the large number of ORs below 1 in this study is unlikely to represent an unknown causal preventive effect of mobile phone exposure: they can be at least partially explained by differential recall by proxies and prodromal symptoms affecting phone use before diagnosis of the cases. We cannot rule out, however, residual confounding from sources we did not measure. Overall, our study provides no evidence of a causal association between wireless phone use and brain tumours in young people. However, the sources of bias summarised above prevent us from ruling out a small increased risk

    Identification of mungbean lines with tolerance or resistance to yellow mosaic in fields in India where different begomovirus species and different Bemisia tabaci cryptic species predominate

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    Mungbean (Vigna radiata (L.) Wilczek) is an important pulse crop in India. A major constraint for improved productivity is the yield loss caused by mungbean yellow mosaic disease (MYMD). This disease is caused by several begomoviruses which are transmitted by the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). The objective of this study was to identify the predominant begomoviruses infecting mungbean and the major cryptic species of B. tabaci associated with this crop in India. The indigenous B. tabaci cryptic species Asia II 1 was found dominant in Northern India, whereas Asia II 8 was found predominant in Southern India. Repeated samplings over consecutive years indicate a stable situation with, Mungbean yellow mosaic virus strains genetically most similar to a strain from urdbean (MYMV-Urdbean) predominant in North India, strains most similar to MYMV-Vigna predominant in South India, and Mungbean yellow mosaic India virus (MYMIV) strains predominant in Eastern India. In field studies, mungbean line NM 94 showed a high level of tolerance to the disease in the Eastern state of Odisha where MYMIV was predominant and in the Southern state of Andhra Pradesh where MYMV-Vigna was predominant, but only a moderate level of tolerance in the Southern state of Tamil Nadu. However, in Northern parts of India where there was high inoculum pressure of MYMV-Urdbean during the Kharif season, NM 94 developed severe yellow mosaic symptoms. The identification of high level of tolerance in mungbean lines such as ML 1628 and of resistance in black gram and rice bean provides hope for tackling the disease through resistance breeding

    Global burden of disease due to smokeless tobacco consumption in adults : analysis of data from 113 countries

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    BACKGROUND: Smokeless tobacco is consumed in most countries in the world. In view of its widespread use and increasing awareness of the associated risks, there is a need for a detailed assessment of its impact on health. We present the first global estimates of the burden of disease due to consumption of smokeless tobacco by adults. METHODS: The burden attributable to smokeless tobacco use in adults was estimated as a proportion of the disability-adjusted life-years (DALYs) lost and deaths reported in the 2010 Global Burden of Disease study. We used the comparative risk assessment method, which evaluates changes in population health that result from modifying a population's exposure to a risk factor. Population exposure was extrapolated from country-specific prevalence of smokeless tobacco consumption, and changes in population health were estimated using disease-specific risk estimates (relative risks/odds ratios) associated with it. Country-specific prevalence estimates were obtained through systematically searching for all relevant studies. Disease-specific risks were estimated by conducting systematic reviews and meta-analyses based on epidemiological studies. RESULTS: We found adult smokeless tobacco consumption figures for 115 countries and estimated burden of disease figures for 113 of these countries. Our estimates indicate that in 2010, smokeless tobacco use led to 1.7 million DALYs lost and 62,283 deaths due to cancers of mouth, pharynx and oesophagus and, based on data from the benchmark 52 country INTERHEART study, 4.7 million DALYs lost and 204,309 deaths from ischaemic heart disease. Over 85 % of this burden was in South-East Asia. CONCLUSIONS: Smokeless tobacco results in considerable, potentially preventable, global morbidity and mortality from cancer; estimates in relation to ischaemic heart disease need to be interpreted with more caution, but nonetheless suggest that the likely burden of disease is also substantial. The World Health Organization needs to consider incorporating regulation of smokeless tobacco into its Framework Convention for Tobacco Control
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