4,700 research outputs found

    Chemical Reaction and Hall Effects on MHD Convective Flow along an Infinite Vertical Porous Plate with Variable Suction and Heat Absorption

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    In this paper an attempt is made to study the chemical reaction and combined buoyancy effects of thermal and mass diffusion on MHD convective flow along an infinite vertical porous plate in the presence of Hall current with variable suction and heat generation. A uniform magnetic field is applied in a direction normal to the porous plate. The equations governing the fluid flow are solved using the perturbation technique and the expressions for the velocity, the temperature and the concentration distributions have been obtained. Dimensionless velocity, temperature and concentration profiles are displayed graphically for different values of the parameters entering into the problem like Prandtl number Pr, Hartmann number M, Grashof number G, modified Grashof number Gc, Hall parameter m, Heat source parameter δ, Schmidt number Sc, and Chemical reaction parameter Kr. The Skin-friction coefficient, rate of heat transfer and mass transfer at the plate have been obtained and also discussed through tables. It has been observed that an increase in the Prandtl number leads to a decrease in the primary and secondary velocities, and also a decrease in the primary and secondary temperatures. The primary and secondary velocities decrease with increase in the Chemical reaction parameter or Magnetic field parameter

    Effects of Radiation Absorption and Mass Transfer on the Free Convective Flow Passed a Vertical Flat Plate through a Porous Medium in an Aligned Magnetic Field

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    This article analyses the effects of radiation absorption and mass transfer on the steady free convective flow of a viscous, incompressible and electrically conducting fluid past an infinite vertical flat plate through a porous medium with an aligned magnetic field. Analytical solutions for concentration, temperature, and velocity are obtained by solving the governing equations in two cases namely (i) when the plate is at uniform temperature and concentration and (ii) when the plate is at constant heat and mass flux. Further the rate of mass transfer in terms of the Sherwood number, rate of heat transfer in terms of Nusselt number and skin friction in terms of shear stress are also derived. The effects of various flow parameters on concentration, temperature, velocity, Sherwood number, Nusselt number and skin-friction affecting the flow field are discussed and analyzed

    Heavy-Fermions in a Transition-Metal Compound: LiV2O4LiV_2O_4

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    The recent discovery of heavy-Fermion properties in Lithium Vanadate and the enormous difference in its properties from the properties of Lithium Titanate as well as of the manganite compounds raise some puzzling questions about strongly correlated Fermions. These are disscussed as well as a solution to the puzzles provided.Comment: late

    Effects of Chemical Reaction and Radiation Absorption on MHD Flow of Dusty Viscoelastic Fluid

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    This investigation is undertaken to study the effects of heat source and radiation absorption on unsteady hydro-magnetic heat and mass transfer flow of a dusty viscous incompressible, electrically conducting fluid between two vertical heated, porous, parallel plates in the presence of chemical reaction under the influence of a transverse applied magnetic field. Initially, the channel walls as well as the dusty fluid are assumed to be at the same temperature and the mass is assumed to be present at low level concentration so that it is constant everywhere. It is also assumed that the dusty particles are non-conducting, solid, spherical and equal in sizes, these are uniformly and symmetrically distributed in the flow field. The governing equations are solved analytically using the perturbation technique. Non-dimensional velocity, temperature, concentration and skin-friction are discussed through graphs for various physical parameters entering into the problem. It is found that velocity of the dusty particles is less than that of the dusty fluid and the skin-friction of the dusty particles is greater than that of the dusty fluid. It is observed that the temperature is minimal at the centre of the channel and decreases towards the plates whereas the concentration is minimal at the center of the channel but increases towards the plates

    Status of vitamin D, lipid profile and carotid artery intima media thickness in patients with chronic kidney disease stage III to V

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    Background: Chronic Kidney Disease (CKD) is characterized by irreversible sclerosis and loss of nephrons. The renal mass progressively declines over a prolonged period, depending on the underlying etiology. In CKD the most common feature is hypovitaminosis D which alter the vascular smooth muscle cell proliferation and reprogram the osteoblastic changes, finally leading to increase arterial wall thickness.Methods: A cross sectional study carried out over a 2-year period in Department Nephrology and General Medicine OPD, MIMS, Vizianagaram, Andhra Pradesh, India. 120 in which 60 are normal healthy individuals and 60 are CKD patients with stage 3 to 5. In all the participants serum creatinine, blood urea, serum triglycerides serum total cholesterol, HDL cholesterol estimated and serum 25 OH vitamin D are estimated.Results: The diagnostic criteria for CKD like blood urea, serum creatinine and eGFR were significantly higher in CKD when compared to control. In the present study, systolic and diastolic blood pressure was significantly increased in CKD compared with control. The Carotid Intima Media Thickness (CIMT) both left and right side were significant higher in CKD when compared with control. There is a significantly decreased levels of serum vitamin D in CKD (14.53 ng/mL±6.88) when compared with control (28.87 ng/mL±6.28).Conclusions: Present study finding suggested that there is a raised value of CIMT in CKD patients. High triglycerides, cholesterol and decreased HDL and declined vitamin D low hemoglobin, decreased eGFR, increased systolic blood pressure, raised CIMT value were found to be significantly increased in CKD patients

    Evaluation of gas phase mass transfer at low reynolds numbers: a new model system

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    A new experimental system is presented which is suitable for studying gas side mass transfer coefficients in packed columns at Reynolds numbers even lower than 1.0. The system involves desorption of iodine from aqueous KI solutions. The reversible complex formation between iodine and iodine ions effectively slows down the concentration changes which otherwise would be too rapid for accurate experimentation

    Diarrhea, CD4 counts and enteric infections in a hospital - based cohort of HIV-infected patients around Varanasi, India

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    Background: As most of the studies in HIV patients with diarrhea were cross sectional, focusing on the etiological agents, we are reporting data on the rate of diarrhea, associations between diarrhea and CD4 counts and variation in frequency of identifying a pathogen with consistency of diarrhea and duration in a prospective hospital based study. Methods: Stool specimens were obtained between Jan 2001 and April 2003 from HIV infected adults with diarrhea presenting to Infectious Disease clinic, Banaras Hindu University, Varanasi. In all patients with diarrhea, specimens were examined by microscopy and cultures to identify pathogens. Results: During the study, 630 person years of observations with diarrhea were analyzed. 140 stool samples were collected representing 43% of episodes of reported diarrhea. Positivity of finding a pathogen from watery stools and formed stools were 40%&24% respectively (p < 0.01) probably due to associated inflammation is more in watery diarrhea. Patients having chronic diarrhea are 2.25 (95%CI 1.52-2.81) times at more risk of developing other opportunistic infections compared to those who don't have. However this is not true with the acute diarrhea where risk of harboring the opportunistic infections remain same. Conclusion: Diarrhea was most strongly associated with low CD4 counts. Over two-thirds of diarrheal episodes were undiagnosed, suggesting that unidentified agents or primary HIV enteropathy are important causes of diarrhea in this population. There is a strong negative association between duration of diarrhea and CD4 levels
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