Formation of annular austenitic ring between outer ferrite layer and solid globule in a semi-solid processed SS 304L

The microstructure of an austenitic SS 304L rapidly quenched from its semi-solid state shows a unique annular austenitic ring in between the core of each globule and its ferritic outer layer. On the basis of experimental results and microstructural analysis, it is proposed that the ring is formed as a result of preferential austenitic phase nucleation in a small quantity of liquid entrapped between adjacent solid globules during rapid quenching, in spite of the fact that ferrite is the thermodynamically stable phase for the alloy. (C) 2014 Elsevier B.V. All rights reserved.

Qualitative toxicity assessment of silver nanoparticles on the fresh water bacterial isolates and consortium at low level of exposure concentration

Silver nanoparticles (AgNPs) pose a high risk of exposure to the natural environment owing to their extensive usage in various consumer products. In the present study we attempted to understand the harmful effect of AgNPs at environmentally relevant low concentration levels (<= 1 ppm) towards two different freshwater bacterial isolates and their consortium. The standard plate count assay suggested that the AgNPs were toxic towards the fresh water bacterial isolates as well as the consortium, though toxicity was significantly reduced for the cells in the consortium. The oxidative stress assessment and membrane permeability studies corroborated with the toxicity data. The detailed electron microscopic studies suggested the cell degrading potential of the AgNPs, and the FT-IR studies confirmed the involvement of the surface groups in the toxic effects. No significant ion leaching from the AgNPs was observed at the applied concentration levels signifying the dominant role of the particle size, and size distribution in bacterial toxicity. The reduced toxicity for the cells in the consortium than the individual isolates has major significance in further studies on the ecotoxicity of the AgNPs. (C) 2014 Elsevier Inc. All rights reserved.

Porous lithium rich Li1.2Mn0.54Ni0.22Fe0.04O2 prepared by microemulsion route as a high capacity and high rate capability positive electrode material

A porous layered composite of Li2MnO3 and LiMn0.35Ni0.55Fe0.1O2 (composition:Li1.2Mn0.54Ni0.22Fe0.04O2) is prepared by inverse microemulsion method and studied as a positive electrode material. The precursor is heated at several temperatures between 500 and 900 degrees C. The X-ray diffraction, scanning electron microscopy, and transmission electron microscopy studies suggested that well crystalline submicronsized particles are obtained. The product samples possess mesoporosity with broadly distributed pores around 10 similar to 50 nm diameter. Pore volume and surface area decrease by increasing the temperature of preparation. However, the electrochemical activity of the composite samples increases with an increase in temperature. The discharge capacity values of the samples prepared at 900 degrees C are about 186 mAh g(-1) at a specific current of 25 mA g(-1) with an excellent cycling stability. The composite sample also possesses high rate capability. The high rate capability is attributed to the porous nature of the material. (C) 2014 Elsevier Ltd. All rights reserved.

Texture Evolution in Nanocrystalline Nickel: Critical Role of Strain Path

The effect of strain path change during rolling on the evolution of deformation texture has been studied for nanocrystalline (nc) nickel. An orthogonal change in strain path, as imparted by alternating rolling and transverse directions, leads to a texture with a strong Bs {110}aOE (c) 112 > component. The microstructural features, after large deformation, show distinct grain morphology for the cross-rolled material. Crystal plasticity simulations, based on viscoplastic self-consistent model, indicate that slip involving partial dislocation plays a vital role in accommodating plastic deformation during the initial stages of rolling. The brass-type texture evolved after cross rolling to large strains is attributed to change in strain path.

Assessment of land surface temperature and heat fluxes over Delhi using remote sensing data

Surface energy processes has an essential role in urban weather, climate and hydrosphere cycles, as well in urban heat redistribution. The research was undertaken to analyze the potential of Landsat and MODIS data in retrieving biophysical parameters in estimating land surface temperature & heat fluxes diurnally in summer and winter seasons of years 2000 and 2010 and understanding its effect on anthropogenic heat disturbance over Delhi and surrounding region. Results show that during years 2000-2010, settlement and industrial area increased from 5.66 to 11.74% and 4.92 to 11.87% respectively which in turn has direct effect on land surface temperature (LST) and heat fluxes including anthropogenic heat flux. Based on the energy balance model for land surface, a method to estimate the increase in anthropogenic heat flux (Has) has been proposed. The settlement and industrial areas has higher amounts of energy consumed and has high values of Has in all seasons. The comparison of satellite derived LST with that of field measured values show that Landsat estimated values are in close agreement within error of 2 degrees C than MODIS with an error of 3 degrees C. It was observed that, during 2000 and 2010, the average change in surface temperature using Landsat over settlement & industrial areas of both seasons is 1.4 degrees C & for MODIS data is 3.7 degrees C. The seasonal average change in anthropogenic heat flux (Has) estimated using Landsat & MODIS is up by around 38 W/m(2) and 62 W/m(2) respectively while higher change is observed over settlement and concrete structures. The study reveals that the dynamic range of Has values has increased in the 10 year period due to the strong anthropogenic influence over the area. The study showed that anthropogenic heat flux is an indicator of the strength of urban heat island effect, and can be used to quantify the magnitude of the urban heat island effect. (C) 2013 Elsevier Ltd. All rights reserved.

Interplay of male traits, male mating strategies and female mate choice in the Asian elephant, Elephas maximus

Elaborate male traits with no apparent adaptive value may have evolved through female mate discrimination. Tusks are an elaborate male-only trait in the Asian elephant that could potentially influence female mate choice. We examined the effect of male body size, tusk possession and musth status on female mate choice in an Asian elephant population. Large/musth males received positive responses from oestrous females towards courtship significantly more often than did small/non-musth males. Young, tusked non-musth males attempted courtship significantly more often than their tuskless peers, and received more positive responses (though statistically insignificant) than did tuskless males. A positive response did not necessarily translate into mating because of mate-guarding by a dominant male. Female elephants appear to choose mates based primarily on traits such as musth that signal direct fertility benefits through increased sperm received than for traits such as tusks that may signal only indirect fitness benefits.

Perceptions of priority issues in the conservation of biodiversity and ecosystems in India

We report on the results of a country-wide survey of people's perceptions of issues relating to the conservation of biodiversity and ecosystems in India. Our survey, mainly conducted online, yielded 572 respondents, mostly among educated, urban and sub-urban citizens interested in ecological and environmental issues. 3160 ``raw'' questions generated by the survey were iteratively processed by a group of ecologists, environmental and conservation scientists to produce the primary result of this study: a summarized list of 152 priority questions for the conservation of India's biodiversity and ecosystems, which range across 17 broad thematic classes. Of these, three thematic classes-''Policy and Governance'', ``Biodiversity and Endangered Species'' and ``Protection and Conservation''-accounted for the largest number of questions. A comparative analysis of the results of this study with those from similar studies in other regions brought out interesting regional differences in the thematic classes of questions that were emphasized and suggest that local context plays a large role in determining emergent themes. We believe that the ready list of priority issues generated by this study can be a useful guiding framework for conservation practitioners, researchers, citizens, policy makers and funders to focus their resources and efforts in India's conservation research, action and funding landscape. (C) 2015 Elsevier Ltd. All rights reserved.

Transport properties of solution processed Cu2SnS3/AZnO heterostructure for low cost photovoltaics

Cu2SnS3 thin films were deposited by a facile sot-gel technique followed by annealing. The annealed films were structurally characterized by grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM). The crystal structure was found to be tetragonal with crystallite sizes of 2.4-3 nm. Texture coefficient calculations from the GIXRD revealed the preferential orientation of the film along the (112) plane. The morphological investigations of the films were carried out using field emission scanning electron microscopy (FESEM) and the composition using electron dispersive spectroscopy (EDS). The temperature dependent current, voltage characteristics of the Cu2SnS3/AZnO heterostructure were studied. The log I-log V plot exhibited three regions of different slopes showing linear ohmic behavior and non-linear behavior following the power law. The temperature dependent current voltage characteristics revealed the variation in ideality factor and barrier height with temperature. The Richardson constant was calculated and its deviation from the theoretical value revealed the inhomogeneity of the barrier heights. Transport characteristics were modeled using the thermionic emission model. The Gaussian distribution of barrier heights was applied and from the modified Richardson plot the value of the Richardson constant was found to be 47.18 A cm(-2) K-2. (c) 2015 Elsevier B.V. All rights reserved.

A Quantitative Analysis of the Effect of Laser Transformation Hardening on Crack Driving Force in Steels

A mechanical model of a laser transformation hardening specimen with a crack in the middle of the hardened layer is developed to quantify the effects of the residual stress and hardness gradient on crack driving force in terms of J-integral. It is assumed

Estudio epidemiológico sobre la prevalencia de brucelosis en hembras bovinas en el municipio de San Pedro de Lóvago, Chontales

La Brucelosis en hembras bovinas se caracteriza por aborto al final de la gestación y afecta a muchos de los animales domésticos y al hombre, con el objetivo de determinar la prevalencia en San Pedro de Lóvago, se desarrolló un "ESTUDIO EPIDEMIOLOGICO SOBRE LA PREVALENCIA DE BRUCELOSIS EN HEMBRAS BOVINAS EN EL MUNICIPIO DE SAN PEDRO DE LÓVAGO" por lo que se realizó un muestreo serológico a un total de 13,915 bovinos en un periodo de Abril - Octubre (2,005), distribuidos en las diferentes comarcas del municipio, de las cuales se tomaron 3,41O, para éste estudio epidemiológico utilizando las técnicas diagnósticas de Rosa de Bengala y Rivanol. Los resultados obtenidos revelan una prevalencia global de 0.06 % y una prevalencia en la comarca Llano de los Pedros de 0.57 %. Por lo que se concluye que en este trabajo de tesis se obtuvieron resultados con una prevalencia muy baja en hembras bovinas analizadas, por lo que recomienda la implementación sistemática de programas de Vigilancia Epidemiológicas y Control, para mantener el nivel de baja prevalencia en el municipio y resto del país.

Comparación de índices productivos y reproductivos de monta natural e inseminación artificial con semen congelado en cerdos

El presente trabajo de tesis se realizó en la granja experimental porcina MAGFOR-Misión China de la república de Taiwán, ubicada en Cofradía. El estudio consistió en la evaluación de los parámetros reproductivos en grupos de cerdas obtenidos por inseminación artificial y grupos obtenidos a través de la monta natural, también se aborda el tema de la consanguinidad y sus consecuencias como un factor negativo en la fijación de caracteres indeseables, esto sucede en las poblaciones en las que existe una alta homocigosis debido al origen común del material genético (padres emparentados). Las variables evaluadas en el presente trabajo fueron: tamaño de la camada al nacimiento, peso promedio de los lechones al nacimiento, peso promedio de los lechones al destete e intervalo parto parto. para el análisis estadístico se elaboraron tablas de contingencias por cada una de las variables con base en los promedios. Para la variable tamaño de la camada al nacimiento se obtuvo para el tratamiento inseminación artificial un promedio de 9.16 lechones y para la monta natural un promedio de 9.89 lechones al contrastar las medias de los dos tratamientos se obtuvo un valor de t de 0.88 que comparado con el valor tabulado al 5% resulto no significativo al observar el comportamiento de las diferentes razas ,la yorkshire obtuvo los mayores promedios en inseminación el caso especifico de esta habían muy pocos ejemplares 6 . Se trabajo en condiciones normales de producción lo cual pudo influir en estos resultados debido al tamaiio de la muestra en esta raza. Los resultados para la variable peso promedio de los lechones al nacimiento, arrojaron un promedio de 1.76 Kg. para las camadas obtenidas por inseminación artificial y 1.67kg para las obtenidas por el método de monta natural en las observaciones de los promedios por razas, se obtuvo el mayor peso a favor de la raza Landrace con 1.99 Kg. seguido de la raza duroc con 1.85 Kg. en el tratamiento de inseminación artificial, y para la monta natural el menor peso lo obtuvo la raza duroc con 1.44 Kg. y elmayor peso fue también la raza Landrace. la raza Yorkshire mostró un comportamiento similar tanto en inseminacion artificial, como en monta natural. Para la variable peso promedio de los lechones al destete, se obtuvo un peso promedio de 7.39 Kg. para los lechones obtenidos por el método de inseminacion artificial y un peso promedio de 6.71 Kg. en el caso de lechones obtenidos por monta natural al evaluar las razas, la raza Landrace obtuvo el mayor peso al destete con 8.01 Kg. como era de esperar al obtener los mayores promedios en peso al nacimiento esto fue para las camadas obtenidas por inseminacion artificial. en el caso. de los lechones obtenidos mediante la monta natural el mayor peso correspondió a la raza Hampshire pudiendo haber influido el numero de lechones, ya que esta fue la que presento el menor numero la raza Yorkshire tuvo en este caso un comportamiento similar en los dos tratamientos. Para la variable intervalo parto-parto, en el caso de las cerdas servidas por el método de inseminacion artificial presentaron un IPP de 5.52 meses o sea 167 días y las cerdas servidas por monta natural obtuvieron un IPP de5.01 meses o 152 días. En la prueba de hipótesis tanto como el contraste de varianza, los resultados fueron significativos y una diferencia de 15 días vacíos en una hembra eleva los costos de producción de una manera considerable por esta razón un IPP como el de la inseminación artificial solo se justifica en la granja experimental porcina en un numero especifico de cerdas elite y como apoyo al mejoramiento genético del hato porcino de esta así como del hato nacional.