1,021 research outputs found

    Analysis of the flow and heat transfer characteristics for MHD free convection in an enclosure with a heated obstacle

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    Finite element method based on Galerkin weighted Residual approach is used to solve two-dimensional governing mass, momentum and energy equations for steady state, natural convection flow in presence of magnetic field inside a square enclosure. The cavity consists of three adiabatic walls and one constantly heated wall. A uniformly heated circular solid body is located at the centre of the enclosure. The aim of this study is to describe the effects of MHD on the flow and thermal fields in presence of such heated obstacle. The investigations are conducted for different values of Rayleigh number (Ra) and Hartmann number (Ha). Various characteristics of streamlines, isotherms and heat transfer rate in terms of the average Nusselt number (Nu) are presented for different parameters. The effect of physical parameter (D) is also shown here. The results indicate that the flow pattern and temperature field are significantly dependent on the above mentioned parameters

    NASA pattern relevance guide. Volume I - General, space science and utilization

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    Management planning aid for evaluation of space programs, specific space science tasks, and technology deficiencie

    Obesity in post menopausal women with a family history of breast cancer: prevalence and risk awareness

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    Background: Obesity and physical activity are modifiable risk factors in the development of postmenopausal breast cancer. The aim of this study was to assess the level of awareness and prevalence of these factors in women attending family history clinics. Methods: Women attending the breast cancer family history clinic from 2004 to 2006 completed a questionnaire (SP15 format) about their knowledge of and exposure to various diet and lifestyle factors. All women had been counselled by a Consultant Cancer Geneticist and were given verbal and written information on the effect of life style on breast cancer risk. Responses were analysed using SPSSâ„¢ software. Results: The response rate was 70% and two thirds of women were post-menopausal. The prevalence of obesity in post-menopausal women was 37% with 40% being overweight. The majority of women consumed a healthy balanced diet. Only 15% of post-menopausal women exercised for more than 4 hours per week. Two-thirds of women correctly stated that obesity increases their breast cancer risk and 73% of these were overweight or obese. Over 87% were correctly aware of the role of family history, 68% of a high fat diet, and 57% of hormone replacement therapy in the development of breast cancer. Conclusion: Women attending family history clinics lead a high risk lifestyle for the development of breast cancer with high prevalence of obesity and low levels of physical activity. A campaign of patient education is needed to promote healthy lifestyle choices, especially physical activity, in these high-risk women

    Thermal Ignition of a Combustible over an Inclined Hot Plate

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    In this study, the ignition characteristics and the flow properties of the mixed convection flow are presented. Detailed formulations of the forced, natural and mixed convection problems have been discussed. In order to avoid inconvenient switch between the forced and natural convection we introduce a continuous transformation in the mixed convection. We make a comparison between these situations which reveal a good agreement. For mixed convection flow, the ignition distance is explicitly expressed as a function of the Prandtl number, reaction parameter and wall temperature. It has been observed that owing to the increase of the aforesaid parameters, the thermal ignition distance is reduced. Numerical results are illustrated for velocity, temperature, and concentration for different physical parameters. Furthermore, the development of combustion is presented by using streamlines, isotherms and isolines of fuel and oxidizer

    Baby Skyrme models for a class of potentials

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    We consider a class of (2+1) dimensional baby Skyrme models with potentials that have more than one vacum. These potentials are generalisation of old and new baby Skyrme models;they involve more complicated dependence on phi_3.We find that when the potential is invariant under phi_3 -> -phi_3 the configuration corresponding to the baby skyrmions lying "on top of each other" are the minima of the energy. However when the potential breaks this symmetry the lowest field configurations correspond to separated baby skyrmions. We compute the energy distributions for skyrmions of degrees between one and eight and discuss their geometrical shapes and binding energies. We also compare the 2-skyrmion states for these potentials. Most of our work has been performed numerically with the model being formulated in terms of three real scalar fields (satisfying one constraint).Comment: LaTeX, 14 pages, 10 figure

    Ab-initio insights into the mechanical, phonon, bonding, electronic, optical and thermal properties of hexagonal W2N3 for potential applications

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    We investigated the structural, elastic, electronic, vibrational, optical, thermodynamic and a number of thermophysical properties of W2N3 in this study using DFT based formalisms. The mechanical and dynamical stabilities have been confirmed. The Pugh and Poisson ratios are located quite close to the brittle to ductile borderline. The electronic band structure and energy density of states show metallic behavior. The Fermi surface features are investigated. The analysis of charge density distribution map clearly shows that W atoms have comparatively high electron density around than the N atoms. Presence of covalent bondings are anticipated. High melting temperature and high phonon thermal conductivity at room temperature of W2N3 imply that the compound has potential to be used as a heat sink system. The optical characteristics demonstrate anisotropy for W2N3. The compound can be used in optoelectronic device applications due to its high absorption coefficient and low reflectivity in the visible to ultraviolet spectrum. Furthermore, the quasiharmonic Debye model is used to examine temperature and pressure dependent thermal characteristics for the first time.Comment: Submitted to Journal of Alloys and Compound

    Effect of NPK on growth, yield and seed quality of hybrid Chilli

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    An experiment was carried out at Germplasm Centre and Plant Biotechnology Lab, Department of Horticulture, PSTU to evaluate the growth, seed yield and quality of hybrid F1 chilli (cv. Sonic) crossing male line (LTSL-004-M) and female line (LTSL-004-F) along the viability of productive seeds influenced by NPK fertilizers during the period from November 2015 to October 2016. Ten different treatments of NPK fertilizers were used. Result showed that all the characteristics except primary branches and1000 seed weight were influenced significantly due to the application of NPK fertilizers. The tallest plant (69.88 cm), more leaves plant–1 (2491.33), highest number of secondary branches plant-1, tertiary branches plant-1 (5.00 and 88.00, respectively), number of flowers and hybrid fruits plant–1 (1533.00 and 12.33, respectively) and weight of seeds (4.03 g plant–1) along with required more time (54.67 days) for flowering were obtained from the application of 145 kg N ha–1, 175 kg P ha–1 and 96 kg K ha–1 (T4) which produced the highest final seed yield of chilli (4.03 kg ha–1). Application of T5 and T9 showed the highest number of primary branches (2.33). In seed viability characteristics T9 treated seeds showed the highest germination (100, 97.33 and 94.97%) at 1st, (1 MAH - Month After Harvest), 2nd (2 MAH) and 3rd (4 MAH) observations, respectively. The T3 treated seeds performed well in respect of Seed Vigour Index (SVI) at 1st and 2nd observations (8.00 and 7.48, respectively) but T9 treated seeds showed the highest SVI (6.32) at 3rd observation. Above indicating all characteristics were lowest under only recommended doses of NPK T1 as control treatment except days to first flowering. The observations suggested that production of hybrid chilli seeds could be enhanced by applying T4. While seeds of chilli treated by T9 in field level showed long time viable. Application of 145 kg N ha–1, 175 kg P ha–1 and 96 kg K ha–1 may be suggested for seed production of chilli and 110 kg N ha–1, + 175 kg P ha–1 + 115 kg K ha–1 for keeping the long time seed viability. Int. J. Agril. Res. Innov. & Tech. 9 (1): 35-41, June, 201
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