Optical and electrical properties of cobalt chloride doped polyvinyl alcohol polyvinylpyrrolidone blend

Films of cobalt chloride doped polyvinyl alc. - polyvinylpyrrolidone blend were prepd. by soln. casting method, in the doping range 0 wt​% up to 42 wt​%. These films were characterized by XRD, UV-​Visible spectrometry, FTIR, thermal anal. and elec. measurements. The films were semi-​cryst., with an av. crystallite size of few nanometers. The optical band gap due to indirect allowed transitions (in k-​space) decreases from 4.6 eV for 1.5 wt​% doping level to 4.0 eV at 35 wt​% doping level. In addn., absorption peaks were obsd. at 2.3 eV, 3.0 eV and 1.7 eV, which indicate that doping results in formation of allowed energy bands within the forbidden gap. The Urbach energy, which measures the width of band tails within the forbidden gap, is found to significantly decrease with increase in doping level. DC elec. measurements show a good fit for 3-​D Variable Range Hopping model of cond. The temp. variation of elec. resistivity obeys the Arrhenius relation, from which the activation energy obtained is found to decrease from 4.1 eV for 1.5 wt​% doping level to 3.1 eV for 19 wt​% doping level. (c) 2014 American Institute of Physics

Microstructural studies on cobalt chloride doped PVA -​PVP blend

Soln. cast films of PVA (polyvinylalc.) and PVP (polyvinylpyrrolidone) blend, doped with cobalt chloride (CoCl2) in the concn. range (doping level) from 1 wt​% up to 28 wt​% were characterized, and the data collected was analyzed to yield information about the microstructure of these films. XRD, DTATGA, ATR-​FTIR, UV-​Vis and DC elec. measurements were performed. Although un-​doped PVA-​PVP blend (equal compn. of PVA and PVP by wt.) was amorphous, the CoCl2 doped films showed a semicryst. nature, the av. crystallite size increasing from 7.5 nm at 9 wt​% doping level up to 19 nm at 26 wt​% doping level. The FTIR and DTA-​TGA spectra were used to complement the information about microstructure of these samples provided by XRD, and also correlated with elec. and optical anal., the latter revealing a higher degree of structural order in CoCl2 doped PVA-​PVP blend films, on increased incorporation of cobalt chloride

Recent Advances in Pigeonpea [Cajanus cajan (l.) Millspaugh) Research

Pigeonpea or red gram [Cajanus cajan (L.) Millspaugh] is an important food legume of the semi-arid tropics of Asia and Africa. It occupies a prime niche in sustainable farming systems of smallholder rainfed farmers. It occupies a prominent place in Indian rainfed agriculture. It is an integral component in various agro ecologies of the country mainly inter cropped with cereals, pulses, oilseeds and millets. It is the second most important pulse crop next to chickpea, covering an area of around 4.42 m ha (occupying about 14.5% of area under pulses) and production of 2.86 MT (contributing to 16% of total pulse production) and productivity of about 707 kg/ha. It is mainly consumed as dry split dhal throughout the country besides several other uses of various parts of pigeonpea plant. Enhancing the productivity of the crop assumes specific significance in India mainly to combat protein malnutrition as it is the main source of protein to the predominant vegetarian population. The productivity of pigeonpea has remained low and stagnant over the last few decades thus this prompted scientists to search for novel ways of crop improvement. To tackle this challenge, ICRISAT and IIPR are working on number of innovative ideas like, genome sequencing (Varshney et al. 2012), development of CGMS hybrids with 30 to 40 % yield advantage over traditional varieties, development of photo insensitive super early maturing lines, introgression of cleistogamous flower structure to maintain genetic purity of elite lines, use of obcordate leaf shape as NEP to assess genetic purity of hybrid parental lines and development of disease resistant hybrids and elite breeding lines. These aspects are described briefly below

Seismic Effects in F2 Region Related to Electron Temperature

Исследовано влияние землетрясений в ионосферном диапазоне F2 с использованием данных индийского спутника SROSS-C2 о космической электронной температуре вокруг Индийского сектора в диапазонах 0—34° N и 40—100° E за период 1995—1997 гг. Проанализировано пять эпизодов землетрясений и наблюдавшиеся аномалии при средней электронной температуре от 29 до 10 % большей, чем в предшествовавшие дни, и от 16 до 4 % большей, чем в дни после землетрясения, а также широтная вариация указанной температуры. Показано, что рост этой температуры был максимальным в день, предшествовавший землетрясению, и в течение нескольких часов до и после него. Аномалии, наблюдавшиеся вокруг (в ±2-градусном широтном диапазоне), были эпицентром землетрясения. Они наблюдались, вероятно, в силу электромагнитного излучения во время активности землетрясения. Период с 1995 по 1997 г. для данного исследования принимали как период спокойных геомагнитных условий.Досліджено вплив землетрусів в іоносферному діапазоні з використанням даних індійського супутника SROSS-C2 стосовно космічної електронної температури навколо Індійського сектору в діапазонах 0—34° N і 40—100° E за період 1995—1997 рр. Проаналізовано п’ять епізодів землетрусів і спостережувані аномалії за середньої електронної температури від 29 до 10 % більшої, ніж у попередні дні, та від 16 до 4 % більшої, ніж у дні після землетрусу, а також широтну варіацію зазначеної температури. Показано, що зростання цієї температури було максимальним у день, що передував землетрусу, і протягом кількох годин до і після нього. Аномалії, що спостерігались навколо (у ±2-градусному широтному діапазоні), були епіцентром землетрусу. Їх спостерігали, ймовірно, завдяки електромагнітному випромінюванню під час активності землетрусу. Період з 1995 по 1997 р. для цього дослідження вважали періодом спокійних геомагнітних умов

Naked Singularity Formation In f(R) Gravity

We study the gravitational collapse of a star with barotropic equation of state $p=w\rho$ in the context of $f({\mathcal R})$ theories of gravity. Utilizing the metric formalism, we rewrite the field equations as those of Brans-Dicke theory with vanishing coupling parameter. By choosing the functionality of Ricci scalar as $f({\mathcal R})=\alpha{\mathcal R}^{m}$, we show that for an appropriate initial value of the energy density, if $\alpha$ and $m$ satisfy certain conditions, the resulting singularity would be naked, violating the cosmic censorship conjecture. These conditions are the ratio of the mass function to the area radius of the collapsing ball, negativity of the effective pressure, and the time behavior of the Kretschmann scalar. Also, as long as parameter $\alpha$ obeys certain conditions, the satisfaction of the weak energy condition is guaranteed by the collapsing configuration.Comment: 15 pages, 4 figures, to appear in GR

Atomic Species Associated with the Portevin–Le Chatelier Effect in Superalloy 718 Studied by Mechanical Spectroscopy

In many Ni-based superalloys, dynamic strain aging (DSA) generates an inhomogeneous plastic deformation resulting in jerky flow known as the Portevin--Le Chatelier (PLC) effect. This phenomenon has a deleterious effect on the mechanical properties and, at high temperature, is related to the diffusion of substitutional solute atoms toward the core of dislocations. However, the question about the nature of the atomic species responsible for the PLC effect at high temperature still remains open. The goal of the present work is to answer this important question; to this purpose, three different 718-type and a 625 superalloy were studied through a nonconventional approach by mechanical spectroscopy. The internal friction (IF) spectra of all the studied alloys show a relaxation peak P718 (at 885 K for 0.1 Hz) in the same temperature range, 700 K to 950 K, as the observed PLC effect. The activation parameters of this relaxation peak have been measured, Ea(P718){\thinspace}={\thinspace}2.68{\thinspace}{\textpm}{\thinspace}0.05 eV, $\tau$0{\thinspace}={\thinspace}2{\textperiodcentered}10-15 {\textpm} 1 s as well as its broadening factor $\beta${\thinspace}={\thinspace}1.1. Experiments on different alloys and the dependence of the relaxation strength on the amount of Mo attribute this relaxation to the stress-induced reorientation of Mo-Mo dipoles due to the short distance diffusion of one Mo atom by exchange with a vacancy. Then, it is concluded that Mo is the atomic species responsible for the high-temperature PLC effect in 718 superallo

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990�2015: a systematic analysis for the Global Burden of Disease Study 2015

Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors�the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25 over the same period. All risks jointly evaluated in 2015 accounted for 57·8 (95 CI 56·6�58·8) of global deaths and 41·2 (39·8�42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million 192·7 million to 231·1 million global DALYs), smoking (148·6 million 134·2 million to 163·1 million), high fasting plasma glucose (143·1 million 125·1 million to 163·5 million), high BMI (120·1 million 83·8 million to 158·4 million), childhood undernutrition (113·3 million 103·9 million to 123·4 million), ambient particulate matter (103·1 million 90·8 million to 115·1 million), high total cholesterol (88·7 million 74·6 million to 105·7 million), household air pollution (85·6 million 66·7 million to 106·1 million), alcohol use (85·0 million 77·2 million to 93·0 million), and diets high in sodium (83·0 million 49·3 million to 127·5 million). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation. © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY licens

Citation Analysis of Theses in Library and Information Science Submitted to University of Pune: A Pilot Study

This is a bibliometric study that used 27 LIS dissertations with a total of 6,257 citations. Most citations are from periodicals (42.2%), mostly from US and Indian journals. Nearly half of the citations recorded are from journal articles: 2,639 (42.2%) Nearly three quarters of the journal articles were from LIS journals, with the remainder from 33 other subject areas. College and Research Libraries is the most cited journal, followed by Scientometrics. Most of the citations are from 55 journals out of the total number

Synthesis and structural studies of Na2O-ZnO-ZnF 2-B2O3 oxyfluoride glasses

This paper describes the synthesis and spectroscopic studies of the glass system, 20Na2O-(20-x) ZnO-xZnF2-60B2O 3 (x = 0, 5, 10, 15, 20), prepared by melt quenching method. The analyses of DSC and XRD did not show the crystallinity of the glass sample. 11B MAS-NMR shows the presence of sharp peak around -14 ppm. From the IR studies, the broadening of the peak around 1200-1400 and 800-1100 cm -1 shows the presence of mixed linkages like B-O-B, B-O-Zn in the network. © Indian Academy of Sciences