685 research outputs found

    Exploring the possibility of enhancing the figure-of-merit ( >> 2) of Na0.74_{0.74}CoO2_{2}: A combined experimental and theoretical study

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    Search of new thermoelectric (TE) materials with high \textit{figure-of-merit} (ZT) is always inspired the researcher in TE field. Here, we present a combined experimental and theoretical study of TE properties of Na0.74_{0.74}CoO2_{2} compound in high-temperature region. The experimental Seebeck coefficient (S) is found to vary from 64 to 118 μ\muV/K in the temperature range 300−620300-620 K. The positive values of S are indicating the dominating p-type behaviour of the compound. The observed value of thermal conductivity (κ\kappa) is ∼\sim 2.2 W/m-K at 300 K. In the temperature region 300−430300-430 K, the value of κ\kappa increases up to ∼\sim 2.6 W/m-K and then decreases slowly till 620 K with the corresponding value of ∼\sim 2.4 W/m-K. We have also carried out the theoretical calculations and the best matching between experimental and calculated values of transport properties are observed in spin-polarized calculation within DFT+\textit{U} by chosen \textit{U} = 4 eV. The maximum calculated value of ZT is found to be ∼\sim 0.67 at 1200 K for p-type conduction. Our computational study suggests that the possibility of n-type behaviour of the compound which can lead to a large value of ZT at higher temperature region. Electron doping of ∼\sim 5.1×\times1020^{20} cm−3^{-3} is expected to give rise the high ZT value of ∼\sim 2.7 at 1200 K. Using these temperature-dependent ZT values, we have calculated the maximum possible values of efficiency (η\eta) of thermoelectric generator (TEG) made by p and n-type Na0.74_{0.74}CoO2_{2}. The present study suggests that one can get the efficiency of a TE cell as high as ∼\sim 11%\% when the cold and hot end temperature are fixed at 300 K and 1200 K, respectively. Such high values of ZT and efficiency suggest that Na0.74_{0.74}CoO2_{2} can be used as a potential candidate for high-temperature TE applications

    Enhanced User-driven Ranking System with Splay Tree

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    E-learning is one of the information and communication technology products used for teaching and learning process [35]. An efficient and effective way to construct trust relationship among peer users in e-learning environment is ranking. User-driven ranking systems are based only on the feedback or rating provided by the users. In [46-48] the authors provide a variety of trust and reputation methods. Certified Belief in Strength (CBS) [45] is a novel trust measurement method based on reputation and strength. In [38] author presents a recommendation system based on the relevant feedback review to predict the user's interests, that are ranked based on the recommendations history they provide previously. Users with higher rating obtain high reputation compared to less scored users. In question answering websites like StackOverflow, new or low scored users are ignored by the community. This discourage them and their involvement with the community reduces further down, as power law states, alleged low users are pushed to the bottom of the ranking list. Avoid this condition by encouraging less reputed users and prevent them from moving further down in ranking level. Thus, low reputed users are provided with few more chances to participate actively in the e-learning environments. A splay tree is a Binary Search Tree with self-balancing skill. The splay tree brings the recently accessed item to the top of the tree, thus active users are always on the top of the tree. A splay tree is used to represent user's ranks, and to semi-splay low ranked users again in the tree thus preventing them from further drowning in the ranking list. The focus of this research work is to find and enhance low reputed users in reputation system by providing few more chances to take part actively in the e-learning environment using the splay tree. Normalized discounted cumulative gain (NDCG) acts as a decision part for identifying drowning users

    PROTECTIVE EFFECT OF COX INHIBITORS ON LIPOPOLYSACCHARIDE INDUCED SICKNESS BEHAVIOUR OR NEUROINFLAMMATION AND OXIDATIVE STRESS ON MALE WISTAR RATS

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    Objectives: The aim of the study was to evaluate the protective effect of COX inhibitors on lipopolysaccharide induced sickness behaviour or neuro inflammation and oxidative stress on male wistar rats.Methods: Male albino wistar rats were divided into 8 groups and each group consisting of 6 rats and drug treatment has done for one week. Control group was given normal saline daily by i. p route for 7 days. Negative control group receives saline for 6 days followed by LPS on 7th day. All other group receives Resveratrol, Celecoxib, and Aspirin for 7 days and LPS (inducing agent) was given on 7th day just before half an hour of drug treatment. After 2 hours of drug administration, the animals were subjected to behavioural testing and after analyzing behavioural parameters, the animals were sacrificed by cervical dislocation in order to perform in vitro studies.Results: The results of this study showed that Celecoxib at 10 and 50 mg/kg p. o. showed no changes in body weight but there is the decrease in the temperature, increase in the locomotor activity, increase in the number of line crossing, head dipping/nose poaking, decrease in the floating time when compared to the negative control group. Resveratrol at 50 and 100 mg/kg p. o. showed a significant increase in the Superoxide Dismutase, Catalase, Glutathione Reductase, and showed significant decrease in the Lipid Peroxide and Nitric Oxide level when compared to the negative control group.Conclusion: It was finally concluded that Celecoxib showed neuro protective activity and Resveratrol showed anti-oxidant property. Â

    Development of Hand-Operated Mechanical Ginger Peeler

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    Ginger, an underground rhizome, is valued as a spice and is used in both dry and fresh form. The process of peeling is labour-intensive and is a time-consuming operation in post-harvest handling of ginger done manually by women labour. To reduce time and labour requirement, a mechanical ginger peeler having a square mesh drum was developed. Peeling trials were conducted for varying drum loads (6kg, 8kg and 10kg), varying drum speeds (35rpm, 40rpm and 45rpm) and for different peeling durations (5 min, 10 min and 15 min). Optimum machine parameters for maximum efficiency were: drum load of 8 kg per batch, operated at drum speed of 40rpm for peeling duration 15 min. Peeling efficiency and material loss at optimum conditions were determined to be 55.60% and 4.68%, respectively. Dry ginger obtained after mechanical peeling was found to contain essential oil at 2%, oleoresin 4.6%, moisture content 9.82% and crude fibre content 2.5%

    Pap smear in antepartum women: an opportunity to screen and create awareness

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    Background: Cervical and breast cancers are the leading malignancies in females in India. Cancer cervix is preventable and treatable if detected at premalignant stage. Pap smear is a recommended screening method for cancer cervix and its precursors. Pap smear screening in antenatal period presents an opportunity to screen for premalignant cervical lesions and genital infections. This study was undertaken to determine the prevalence of abnormal cervical smears and genital infections among antenatal women.Methods: It is a prospective study in which, 200 antenatal mothers at booking visit, were included in the study. Details on their demographic characteristics, obstetric profile, and past history of Pap test were collected. Liquid based cytology was used for the test. The cytological results were reported based on the Bethesda classification system 2001.Results: Among 200 antenatal women 57% were between 21-25 yrs of age and 18% were less than 20 years. 38% of women were less than 20 years of age at the time of beginning of sexual activity. 56% were primi gravida and others were multi gravida. 95.5 % of women were literate. 89% of women were unaware of Pap smear test. Among the 200 Pap smear reports, 23% were normal, 55.5% nonspecific inflammatory changes, 8.5% Candida infection and 13% bacterial vaginosis. None were reported with premalignant changes.Conclusions: In a population where people do not undergo Pap test due to varied reasons, antenatal Pap test not only provides an excellent opportunity to screen and create awareness for further screening, also helps detect genital infections

    Structure of Rat Kidneys Following Microwave Accelerated Fixation

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    In contrast to fixation of tissue in externally heated fixative, microwave-irradiation can generate uniform internal heat, which is of utmost importance for successful fixation of biological tissue. To evaluate the effectiveness of microwave-accelerated chemical fixation, we compared the structure of rat kidney fixed by a conventional method and a microwave-accelerated method, by scanning and transmission electron microscopy. Following perfusion, rat kidney pieces 1-2 mm in size were irradiated in Karnovsky\u27s fixative in a domestic Amana microwave oven, till the temperature of the fixative reached 45-50°C. For conventional fixation, tissue pieces were fixed overnight at room temperature in the same fixative. Both types of samples were processed further for electron microscopy using identical protocols. The microwave fixed samples showed excellent preservation of structure comparable to the samples fixed by the conventional method. Glomeruli and the renal tubules showed normal morphology with no cellular swelling. The cytoplasm and nuclear matrix of the epithelial cells was uniformly dense. Other fixation sensitive organelles like mitochondria and Golgi apparatus showed superior preservation with continuous membranes. These results demonstrate that microwave accelerated chemical fixation results in excellent preservation of tissue structure, reduces processing time significantly and is therefore a practical alternative to conventional protocols

    Effect of soil pH on sorption of salinomycin in clay and sandy soils

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    Salinomycin is polyether ionophore, commonly used in poultry industry for the prevention of coccidial infections and promotion of growth. A large amount of the administered antibiotic is excreted as parent compound, eventually reaching agricultural lands. This makes it imperative for researchers to understand the behavior of the compound in soil environment by conducting sorption-desorption studies. In this study, sorption of salinomycin was measured in four agricultural soils, a clay soil with low organic matter content (LOM), a clay soil with high organic matter content (HOM), a sandy soil with HOM, and a loamy sandy (LOM) soils, at three pH levels, namely 4, 7 and 9. Desorption studies was carried out using the batch equilibration technique. It was observed that more than 98% salinomycin was strongly sorbed by all soils, irrespective of the soil organic matter content or soil pH. The sorption of salinomycin to the sandy soil marginally increased as the pH decreased, while the sorption to the two clay soils marginally increased as the pH increased. Desorption of salinomycin with methanol over a 72 h period was < 0.2% of the amount added; however, it was > 70% with a phosphate buffer (pH 7). Since the phosphate buffer would mimic, to some extent, the quality of water flowing through field soils containing various salts, it was concluded that salinomycin could pose significant threats to both shallow ground water and surface water bodies.Key words: Salinomycin, sorption, pH, desorption, environmental pollution, phosphate buffer

    Infant feeding practices in an urban tertiary care hospital: A descriptive longitudinal study

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    Background: Infant and young child feeding are the corner stone for child development. More than a third of the world’s undernourished children reside in India. Inadequate infant and young child feeding practices with inadequate care and management of common illnesses contributes to malnutrition. Objective: To study the prevailing infant feeding practices and determine influence of factors on infant feeding in a tertiary care hospital. Materials and Methods: A descriptive longitudinal follow-up study was conducted in a tertiary care hospital between November 2010 and April 2012. Maternal and baby’s profiles were obtained using oral questionnaire after birth by personal one-to-one interview. These cases were followed up for their infant feeding practices till 1 year of age in outpatient department and also by telephonic conversation. Continous variables were analysed by mean and SD. For categorical variable frequency and percentage were determined. Results: 61.25% mothers had initiated breastfeeding within 1 h. Prelacteal feed was given to 28.6% babies. 61.5% had initiated complementary feed at 6 months. Bottle feeding was preferred mode of feeding. There was a statistically significant association between initiation of breastfeeding and parity (p=0.022) and type ofdelivery (p<0.0001), religion and complementary feeding introduction (p<0.001), religion and duration of exclusive breastfeeding (EBF) (p=0.003), occupation and EBF duration (p=0.005), education (p=0.015), and religion (p=0.001) were associated with prelacteal feeds. Conclusions: Infant feeding practices observed from the study include early initiation of breastfeeding, appropriate duration of EBF, and timely introduction of complementary feed. Practice of prelacteal and bottle feeding was seen. Infant feeding practices are found to be influenced by several socio-demographic factors

    Seaweed extract as a biostimulant for legume crop, green gram

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    The aim of this research is to investigate the effect of seaweed extracts obtained from the marine green algae, Ulva lactuca Linnaeus, Caulerpa scalpelliformis (R. Brown ex Turner) C. Agardh, brown algae Sargassum plagiophyllum C. Agardh, Turbinaria conoides (J. Agardh) Kutzing, Padina tetrastromatica Hauck, Dictyota dichotama (Hudson) J. V. Lamouroux on the stimulate germination, growth parameters of the Vigna radiata. The present study reveals the seeds germination, fresh weight and dry weight of shoots and roots. These results suggested that seaweed extracts stronger induce seed germination and growth parameters
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