1,423 research outputs found
Reaching the Unreached: Community Based Village Knowledge Centres and Village Resources Centres
No full textThe book explores the history, initiatives and achievements of the M. S. Swaminathan Research Foundation (MSSRF). These include the bio-village initiative, designed to encourage the development of market driven on-farm and non-farm enterprises, and unskilled to skilled work through the sustainable use of natural resources; as well as the Village Through the VKCs (Village Knowledge Centres). The aim is to bridge the digital divide and thus address social exclusion and poverty associated with it. Through Village Resource Centres and VKC information and technology communication for development (ICT4D) strategies many communities in India have been positively impacted
Loading on a vertical cylinder near mean water level in long-and-short-crested waves
No full textThis paper presents the results of an experimental investigation on wave forces on a vertical cylinder in the splash zone. The cylinder was subjected to long- and short-crested waves corresponding to JONSWAP spectra, and sectional loads were measured on force sleeves up to mean water level. Ambient particle velocities were measured by means of perforated ball velocity metres whose performance in intermittent flow was checked with reference to a Laser Doppler Anemometer. Maximum Keulegan-Carpenter numbers were about 24, and maximum Reynolds numbers about 8.5 x 104. Analysis of the measurements concentrated on determining the effect of wave directionality on loading at mean water level. Comparison with earlier results for the submerged part of the cylinder suggests that in the splash zone directionality leads to stronger attenuation of loading than at lower elevations. The changes in loading are rather greater than those predicted by Dean's (1977) hybrid theory
Loading on a vertical cylinder in multidirectional waves
No full textThis paper presents laboratory measurements of local and total loading on an isolated vertical cylinder in irregular unidirectional and multidirectional waves. Maximum Keulegan-Carpenter numbers in individual waves were about 16, and maximum Reynolds numbers about 3 × 104. It is shown that in these conditions, existing theoretical and numerical models underestimate the reduction in loading on a cylinder due to wave spreading. Besides the changes that are predicted when Morison's equation is used with constant coefficients, there are hydrodynamic influences that contribute further force reductions. Comparisons with Dean's (1977) hybrid approach suggest that in the present conditions these reductions are in the region of 3 and 6 percent for a spreading function cos2s , with s = 8 and s = 2, respectively. Larger reductions can be expected at higher Keulegan-Carpenter numbers, though scale effects are likely to become more important in the drag-dominated regime
Local forces on a vertical cylinder in regular and irregular waves
No full textThis paper presents results from an experimental investigation on the loading on a rigid slender vertical circular cylinder in undirectional regular and irregular waves. The ambient flow was measured directly, so that the derived results would not be subject to additional uncertainties associated with the use of wave theories. Morison drag, inertia and lift coefficients are computed from forces measured at one force sleeve and compared with data obtained at the same Reynolds and Keulegan Carpenter numbers, but under uniform flow conditions in a U-tube. In regular waves, the results show the importance of the non-uniformity of wave-induced flow, and in irregular waves it is clear that the loading is much influenced by the history of the flow.NRC publication: Ye
Author Correction: COVID-19 vaccine guidance for patients with cancer participating in oncology clinical trials
No full textIn the original version of this Perspective, the name of the author Giuseppe Curigliano was incorrectly written as Guiseppe Curigiliano. The affiliations have been corrected in the HTML and PDF versions of the manuscrip
Treatment of rubber thread manufacturing industry wastewater by an upflow anaerobic filter / R.M. Subbiah.
No full textAn Application of Transformed Distribution: Length of Stay in Hospitals
No full textLength of stay in hospitals are mostly characterized as asymmetric, right skewed and leptokurtic in nature. Earlier studies have considered parametric distributions like gamma, Pareto, lognormal for studying length of stay of patients in hospitals. However, in this study we have proposed transformed distributions to be the best choice for characterizing the length of stay. For this study, we have considered paediatric asthma dataset and identified that transformed Weibull-Pareto as the best fit. For a comparative purpose we have also provided the results of gamma, lognormal, and Pareto distributions. Maximum likelihood approach is considered to estimate the unknown parameters of the Transformed distribution followed by goodness of fit tests to examine the suitability of the fitted distributions. The results provide a direction for modelling the length of stay in hospitals due to different medical problems which require hospitalization
Performance Comparison of Heterogeneity Measures for Count Data Models in Bayesian Perspective
No full textRandom effects model is one of the widely used statistical techniques in combining information from multiple independent studies and examine the heterogeneity. The present study has focussed on count data model which is comparatively uncommon in such research studies. Also the interest is to exploit the advantage of Bayesian modelling by incorporating plausible prior distributions on the parameter of interest. The study is illustrated with a data on rental bikes obtained from UC Irvine Machine Learning Repository. Results have indicated the impact of prior distributions and usage of heterogeneity estimators in count data models
All Set for Efficient and Reliable Perovskite/Silicon Tandem Photovoltaic Modules?
No full textOver the past few years, perovskite solar cells have arisen as a technology to potentially side with mainstream silicon photovoltaics (PVs) to help drive the transition towards renewable sources of energy. The coupling of perovskites with silicon in a tandem configuration may accelerate this development due to the remarkably high power conversion efficiencies possible with such devices. However, most of the perovskite/silicon tandem achievements so far have been confined to the lab environment, with only a few reported tests under outdoor conditions, using packaged devices. Nevertheless, one of the major challenges for perovskite/silicon tandem technologies, in addition to scale-up, lies in the cell-to-module (CTM) translation, which for the perovskite/silicon tandem concept is complicated by perovskite-imposed constrains such as a low-temperature resilience, imposing challenges regarding tabbing and lamination, as well as a high sensitivity to moisture ingress, mandating the search for adequate encapsulation materials and methods. Herein, these challenges are described and assessed in depth and a perspective on future directions toward module design, tailored for perovskite/silicon tandem PVs is given, combining high performance with excellent durability. The discussion also holds relevance for all-perovskite and other emerging PV technologies seeking market entry
Effect of finite edge radius on ductile fracture ahead of the cutting tool edge in micro-cutting of Al2024-T3
No full textEvidence of ductile fracture leading to material separation has been reported recently in ductile metal cutting [S. Subbiah, S.N. Melkote, ASME J. Manuf. Sci. Eng. 28(3) (2006)]. This paper investigates the effect of finite edge radius on such ductile fracture. The basic question of whether such ductile fracture occurs in the presence of a finite edge radius is explored by performing a series of experiments with inserts of different edge radii at various uncut chip thickness values ranging from 15 to 105 m. Chip–roots are obtained in these experiments using
a quick-stop device and examined in a scanning electron microscope. Clear evidence of material separation is seen at the interface zone between the chip and machined surface even when the edge radius is large compared to the uncut chip thickness. Failure is seen to occur at the upper, middle, and/or the lower edges of the interface zone. Based on these observations, a hypothesis is presented for the events leading to the occurrence of this failure when cutting with an edge radius tool. Finite element simulations are performed to study the nature of stress state ahead of the tool edge with and without edge radius. Hydrostatic stress is seen to be tensile in front of the tool and hence favors the occurrence of ductile fracture leading to material separation. The stress components are, however lower than those seen with a sharp tool.Accepted versio
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