158,310 research outputs found

    Thermal annealing behaviour on electrical properties of Pd/Ru Schottky contacts on n-type GaN

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    We have investigated the electrical properties of Pd/Ru Schottky contacts on n-GaN as a function of annealing temperature by current-voltage (I-V) and capacitance-voltage (C-V) measurements. The Schottky barrier height of the as-deposited Pd/Ru contact is found to be 0.67 eV (I-V) and 0.79 eV (C-V), respectively. Measurements showed that the Schottky barrier height increased from 0.68 eV (I-V) and 0.80 eV (C-V) to 0.80 eV (I-V) and 0.96 eV (C-V) as the annealing temperature is varied from 200 °C to 300 °C. Upon annealing at 400 °C and 500 °C, the Schottky barrier height decreased to 0.73 eV (I-V) and 0.85 eV (C-V) and 0.72 eV (I-V) and 0.84 eV (C-V), respectively. It is noted that the barrier height further decreased to 0.59 eV (I-V) and 0.72 eV (C-V) when the contact is annealed at 600 °C. The change of Schottky barrier heights and ideality factors with annealing temperature may be due to the formation of interfacial compounds at the Ru/Pd/n-GaN interface. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2788

    Parental Selection for Productivity Improvement in Indian Tropical Tasar Silkworm, Antheraea mylitta Drury (Lepidoptera: Saturniidae)

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    Global demand for Vanya silks in general and tasar silk in particular, call-for sustainable utilization of the country’s seri-biodiversity potential. Viability and productivity proportion of tasarculture in terms of seeds, cocoons and essentially raw silk, need attention for its vital role in reforming the livelihood and economic condition of tribal farmers. The conventional approaches on basic stock maintenance, commercial seed production, selective use of parental races or parents for heterosis and heterobeltiosis, method of backcrossing to exploit the traits of commercial importance and applying the advantage of genotype x environment (G x E) interactions are indispensable. In spite of current knowledge on sophisticated transgenic silkworm, appropriate application of on-hand parental resource material and methodologies can expedite tasar silk productivity improvement in addition to up-keep of the agro based cottage industry’s cost-effectiveness

    The effect of environment on post surgical overall well-being and pain sensitivity in an animal model

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    With chronic post surgical pain affecting up to one third of patients undergoing surgeries and the price of treatment being astoundingly high there has been a transition in research to investigate and identify risk factors. Through identification of risk factors new preventative measures can be taken to ensure better surgical outcomes. The role that psychosocial factors can play in the development of chronic post surgical pain has long been recognized yet its mechanisms are still unknown. We aim to investigate how environment can play a direct role in pain perception and sensitivity. We used a Chronic Mild Stress (CMS) paradigm to induce depression in 10 adult male mice, we used 10 control mice who were left in standard opti cages, and 10 enriched mice who were placed in large enrichment cages. CMS mice were exposed to a series of stressors and all mice underwent spared nerve injury surgery. During spared nerve injury the common peroneal and tibial branches of the sciatic nerve were severed while the sural branch was left intact. Overall well-being and pain threshold of mice were tested via Von Frey, Hot Plate, Heat Place Preference, Dynamic Weight Bearing, Hole Board, and Social Interaction. It was found that CMS mice experienced thermal hyperalgesia yet normal thermal threshold sensation. CMS mice also spent less time interacting with novel mice in social interaction, and less amount of time exploring the center of the hole board arena than control or enriched mice. While Von Frey results did not change over the course of the experiment, dynamic weight bearing results indicated spared nerve injury surgery was successful and produced chronic pain. Results indicate that environment plays a role in thermal pain perception and CMS affected overall well being of mice as CMS mice exhibited more timid and anxious behavior

    Asymmetric development of Cotyledons of Tomato Embryo: Testing the prediction of Self-Organization

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    Developmental biologists have long strived to understand how organisms acquire shape and form. The architecture of the mature plant is established during embryogenesis. They have learned much about how gene expression controls the specification of cell type and about how cells interact with one another to coordinate such specific decisions. Far less is known about autocatalytic feedback flow of resource molecules regulating a plant and its parts, shape and form. Indeed, it has even been proposed that the development of shape is not under genetic control but rather is determined by physical forces. Asymmetric development of sinks that depend on common resource pool has been viewed as a consequence of autocatalytic feedback process of flow of resource units into them. The feedback process implies that the stronger a sink is relative to its competitors, the greater is its probability of getting further resources as a non-linear function of its resource drawing ability and sink size. We have shown that this model contrasts with that of sink strength dependent model in its prediction of the subsequent development of the initial asymmetry of growing cotyledons of the tomato embryo (_Lycopersicon esculentum L._), when their resource drawing ability is enhanced by exogenous application of the growth regulators (NAA, GA and BA), we test these prediction and show that the results are in conformity with the autocatalytic model proposed by Ganeshaiah and Uma Shaanker

    Supply Side Constrains in Production of Pulses in India: A Case Study of Lentil

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    In India, annual production of pulses ranges from 11 Mt to 15 Mt, with yield of about 600 kg/ha. Due to the wide gap between supply and demand, import of pulses has increased from 0.38 Mt in 1993 to 2.82 Mt in 2008. Lentil is an important rabi pulse crop with a production of 0.85-0.95 Mt in India, after gram. The study has used both secondary and primary data collected from on-farm demonstrations and farmers’ fields to examine the ways to enhance the domestic supply of lentil. The study has found that there is a scope of increasing area under lentil during the rabi season, as its cost per hectare is less with higher net returns than the competing crops like wheat, gram and mustard in water-deficit and resource-poor conditions. There are large returns for adoption of disease management (80 per cent increase in net return), and improved small-seeded varieties (about 40 per cent increase in net return) in lentil. The study has found that lentil-based cropping systems are profitable and also have high water productivity, hence are suitable for mostly un-exploited rice-fallows under water-deficit conditions. Even though marketed surplus ratios have increased in recent years, there is a post-harvest loss to the extent of 7 per cent of production which needs to be curtailed to increase overall supply for final consumption. There is a case for larger institutional and policy support for pulse crops, keeping visible effects of pulse crops in increasing yield of subsequent crops in crop rotations.Agricultural and Food Policy,

    Physiological antioxidant system and oxidative stress in stomach cancer patients with normal renal and hepatic function

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    Role of free radicals has been proposed in the pathogenesis of many diseases. Gastric cancer is a common disease worldwide, and leading cause of cancer death in India. Severe oxidative stress produces reactive oxygen species (ROS) and induces uncontrolled lipid peroxidation. Albumin, uric acid (UA) and Bilirubin are important physiological antioxidants. We aimed to evaluate and assess the role of oxidative stress (OS) and physiological antioxidant system in stomach cancer patients. Lipid peroxidation measured as plasma Thio Barbituric Acid Reactive substances (TBARS), was found to be elevated significantly (p=0.001) in stomach cancer compared to controls along with a decrease in plasma physiological antioxidant system. The documented results were due to increased lipid peroxidation and involvement of physiological antioxidants in scavenging free radicals but not because of impaired hepatic and renal functions

    Cerium: the lithium substitute in post-AGB stars

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    In this letter we present an alternative identification for the line detected in the spectra of s-process enriched low-mass post-AGB stars around 6708A and which was interpreted in the literature as due to Li. Newly released line lists of lanthanide species reveal, however, the likely identification of the line to be due to a CeII transition. We argue that this identification is consistent with the Ce abundance of all the objects discussed in the literature and conclude that in none of the low-mass s-process enriched post-AGB stars there is indication for Li-production.Comment: 5 pages, 2 figures, accepted for publication as A&A Lette
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