Radiation and mass transfer effects on an unsteady MHD free convection flow past a heated vertical plate in a porous medium with viscous dissipation

An unsteady, two-dimensional, hydromagnetic, laminar free convective boundary-layer flow of an incompressible, Newtonian, electrically-conducting and radiating fluid past an infinite heated vertical porous plate with heat and mass transfer is analyzed, by taking into account the effect of viscous dissipation. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. Numerical evaluation of the analytical results is performed and graphical results for velocity, temperature and concentration profiles within the boundary layer and tabulated results for the skin-friction coefficient, Nusselt number and Sherwood number are presented and discussed. It is observed that, when the radiation parameter increases, the velocity and temperature decrease in the boundary layer, whereas when thermal and solutal Grashof increases the velocity increases

ORIGINAL ARTICLE: Identification of Practical Pharmacology Skills Useful for Good Clinical Practice

Background: Awareness about animal ethics is increasing everywhere. This increased awareness coupled with strict regulations discouraging the use of animals for routine experiments have tied the hands of many pharmacologists. They are now forced to develop alternative experiments without using animals. At present, there is acute need to come out with more innovative and useful practical exercises for pharmacology practical sessions. In this background, the present study was undertaken to develop the much-needed alternative experiments. Aims and Objective: To identify new pharmacological practical skills useful for good clinical practice. Material and Methods: A pre-tested questionnaire was administered to 110 doctors of different categories like house surgeons, postgraduate students, assistant professors and professors who are working in a tertiary care hospital. They were asked to give their suggestions regarding new pharmacology practical skills useful for good clinical practice. Statistical analysis: Responses of the participants to the questions asked were tabulated and analyzed. Suggestions given by them were listed out and studied. Results: Use of emergency drugs, dosage calculation, drugs used in pregnancy, case discussions and prescription writing exercises received a lot of support from the participants. Research methodology, cost calculation, animal experiments and interpretation of data of animal experiments did not receive support from the participants. Suggestions given by the participants regarding useful pharmacological skills belonged to the areas like therapeutics, safe use of drugs, recent advances, analysis of information given by the medical representatives and analyzing articles in journals for knowing the efficacy of drugs. Conclusion: Exercises relevant to the clinical practice, as identified in this study, can be introduced as practical pharmacology exercises. Steps are to be taken to highlight the importance of research methodology and pharmaco-economics to the undergraduates

Process optimization of supercritical carbon dioxide (SC-CO2) extraction parameters for extraction of deoxynojirimycin (1-DNJ) from mulberry (Morus alba L.) leaves

In the present study, supercritical fluid extraction (SFE) technology was applied to extract deoxynojirimycin (1-DNJ) from mulberry leaf powder using carbon dioxide (CO2) as major extraction solvent with ethanol as cosolvent, and extraction parameters such as pressure (100, 150 and 200 bar), temperature (40, 50 and 60 °C) anddynamic extraction time (40, 60 and 80 min) were systematically investigated by full factorial design to obtain the optimum extraction efficiency and extraction yield. Under optimized conditions (pressure of 200 bar, temperature of 50 °C and dynamic extraction time of 80 min), DNJ enriched extract was obtained with high extraction efficiency (96.46 %) and extraction yield (13.41 %), enabling this product to use for nutraceutical purpose. The results indicated that SC-CO2 extraction is a promising and alternative process for recovering the bioactive compounds from mulberry leaves

3D discomfort from vertical and torsional disparities in natural images

The two major aspects of camera misalignment that cause visual discomfort when viewing images on a 3D display are vertical and torsional disparities. While vertical disparities are uniform throughout the image, torsional rotations introduce a range of disparities that depend on the location in the image. The goal of this study was to determine the discomfort ranges for the kinds of natural image that people are likely to take with 3D cameras rather than the artificial line and dot stimuli typically used for laboratory studies. We therefore assessed visual discomfort on a five-point scale from ‘none’ to ‘severe’ for artificial misalignment disparities applied to a set of full-resolution images of indoor scenes. For viewing times of 2 s, discomfort ratings for vertical disparity in both 2D and 3D images rose rapidly toward the discomfort level of 4 (‘severe’) by about 60 arcmin of vertical disparity. Discomfort ratings for torsional disparity in the same image rose only gradually, reaching only the discomfort level of 3 (‘strong’) by about 50 deg of torsional disparity. These data were modeled with a second-order hyperbolic compression function incorporating a term for the basic discomfort of the 3D display in the absence of any misalignments through a Minkowski norm. These fits showed that, at a criterion discomfort level of 2 (‘moderate’), acceptable levels of vertical disparity were about 15 arcmin. The corresponding values for the torsional disparity were about 30 deg of relative orientation

Experimental Characterisation of GLass Aluminum REinforced (GLARE™) laminates

Fibre metal laminates such as GLARE™ have found promising application in the aerospace industry. These laminates were developed at the structures and materials laboratory of Delft University of Technology, Netherlands. GLARE™ is a material belonging to the family of Fibre Metal Laminates consisting of thin aluminum layers bonded with unidirectional S2-Glass fibres with an adhesive. Aluminum and S2-Glass when combined as a hybrid material can provide best features of the both metals and composites. These materials have excellent fatigue, impact and damage tolerance characteristics and a lower density compared to aluminum. GLARE™ has found major application in front and aft upper fuselage, leading edges of empennages of advanced civil aircrafts like A380. This document looks into the evaluation of two configuration of GLARE™ for its mechanical and impact characteristics. The mechanical characterisation was carried out for tensile, compression, Flexure, ILSS, Open Hole Tension, Open Hole Compression and Shear (Iosipescu). The impact behaviour were characterised based on a low velocity drop weight impact carried on these laminates. The study shows that the basic properties evaluated were more dictated by the property of the S2-Glass used. The studies show that GLARE™ laminates posses’ high impact damage resistance compared to other composite material. All the test datas generated for this study will be brought out in this document

Computational analysis of viscous dissipation and joule-heating effects on non-Darcy MHD natural convection flow from a horizontal cylinder in porous media with internal heat generation

In the present paper we examine the effects of viscous dissipation, Joule heating and heat source/sink on non-Darcy MHD natural convection heat transfer flow over permeable horizontal circular cylinder in a porous medium. The boundary layer equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite difference scheme. A parametric study illustrating the influence of Darcy parameter (Da), Forchheimer parameter (Λ), Grashof number(Gr), heat source/sink parameter (Ω) and viscous dissipation parameter (Ec) on the fluid velocity, temperature as well as local skin-friction and Nusselt numbers is conducted Increasing Forchheimer inertial drag parameter (Λ) retards the flow considerably but enhances temperatures. Increasing viscous dissipation parameter(Ec) is found to elevate velocities i.e. accelerate the flow and increase temperatures. Increasing heat source/sink parameter (Ω) is found to elevate velocities and increase temperatures. Increasing the Grashof number (Gr) is found to elevate the velocity and decrease the temperatures. Local skin friction number is found to be increases with increasing heat source/sink parameter (Ω) where as Local Nusselt number is found to decrease with increasing heat source/sink parameter (Ω)

Three-dimensional photoelastic study of the load-carrying capacity/face width ratio of Wildhaber-Novikov gears for automotive applications

Wildhaber-Novikov gears are becoming more and more popular for heavy load applications. They have been tried as speed-reducing gears, in spite of heavy noise generation, in aircraft jet engines, marine engines and agricultural machinery. These circular-arc gears, though stronger than involute geras, have the disadvantage of needing larger face width. Axial face width required can be minimized only at the expense of load-carrying capacity. This is not a serious disadvantage with stationary engines. But in the case of automotive applications, this fact limits the load-carrying capacity of Wildhaber-Novikov gears, since space problem is very critical in these applications and large face widths, therefore, cannot be used for such gear-reduction units. The face width is determined by the helix angle and, therefore, a thorough investigation of the dependence of the load-carrying capacity on helix angle is necessary, if these special types of gears have to make headway into the automotive field. In this experimental investigation, three-dimensional photoelastic technique has been employed to study the load-carrying capacity/face width ratio. Three-dimensional gear models made of epoxy castings (Araldite B) were loaded in a specially built gear-loading fixture and were stress frozen. Gear cutters of Wildhaber-Novikov gears developed at the laboratory were used for the preparation of these three-dimensional gear models. The stress-frozen models were analyzed using the conventional slicing technique to study the contact and bending-stress distribution along the face width. The load-carrying capacity in terms of contact stress and bending stress has been studied for different face widths and helix angles. Twenty-deg pressure angle, 14-mm module gears of alladdendum type of Wildhaber-Novikov gears with different helix angles up to 40 deg were tested. The helical-overlap ratio used was 1.0. The conventional profile parameters were employed for the manufacture of gear cutters of end-mill type. The decrease in contact and bending strength with increase in the helix angle or decrease in the face width, as obtained from this photoelastic method of stress analysis has been compared with existing theoretical results. © 1977 Society for Experimental Mechanics, Inc

Decorrelation of User Defined Function Invocations in Queries

Queries containing user-defined functions (UDFs) are widely used, since they allow queries to be written using a mix of imperative language constructs and SQL, thereby increasing the expressive power of SQL; further, they encourage modularity, and make queries easier to understand. However, not much attention has been paid to their optimization, except for simple UDFs without imperative constructs. Queries invoking UDFs with imperative constructs are executed using iterative invocation of the UDFs, leading to poor performance, especially if the UDF contains queries. Such poor execution has been a major deterrent to the wider usage of complex UDFs

Study of Magnetic Properties of A_2B^'NbO_6 (A=Ba,Sr, (BaSr): and B^'=Fe and Mn) double perovskites

We have studied the magnetic properties of Ba_2FeNbO_6 and Ba_2MnNbO_6. it is seen that Ba_2FeNbO_6 is an antiferromagnet with a weak ferromagnetic behaviour at 5K while Ba_2MnNbO_6 shows two magnetic transitions one at 45 K and the other at 12K. Electron spin resonance (ESR) measurements at room temperature show that the Mn compound does not show any Jahn-Teller distortion. It is also seen that the Neel temperature of the A_2FeNbO_6 (A=Ba,Sr, BaSr) compounds do not vary significantly. However variations in the average A-site ionic radius influence the formation of short range correlations that persist above T_N.Comment: 10 oages, 5 figures, MMM, to appear in J.Appl.Phy