Vadodara, India
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Kumar K.S.,Navrachana University | Samnani P.B.,M. S. University of Baroda
International Journal of ChemTech Research | Year: 2014

A new gradient reversed-phase liquid chromatographic method was developed for the simultaneous determination of Esomeprazole, Venlafaxine HCl and Fenofibrate in water. The chromatographic separation of these analytes was done by C18 column using a mixture of acetonitrile: buffer (0.3 % formic acid) in the ratio 25:75 (v/v) as mobile phase A and in the ratio 30:70 (v/v) as mobile phase B at a wavelength of 230 nm. The Linearity of the method was found to be in the concentration range of 10.37-518.40 mg / L for three drugs with correlation coefficient greater than 0.999.

Desai P.,Navrachana University | Kant T.,Indian Institute of Technology Bombay
International Journal of Pressure Vessels and Piping | Year: 2013

A simplified and accurate semi analytical - numerical model is presented here to investigate the behavior of cylinders of finite length subjected to partially distributed band load. A diaphragm supported laminated cylinder under symmetric load which is considered as a two dimensional (2D) plane strain problem of elasticity in (r, z) direction. The boundary conditions are satisfied exactly in axial direction (z) by taking an analytical expression in terms of Fourier series expansion. Fundamental (basic) dependent variables are chosen in the radial coordinate of the cylinder. First order simultaneous ordinary differential equations are obtained as mathematical model which are integrated through an effective numerical integration technique by first transforming the boundary value problem (BVP) into a set of initial value problems (IVPs). The proposed method is successful in handling the 2D and three dimensional (3D) elasticity problems involving wide range of loadings, material properties and mixed variables. For cylinders subjected to band load, the convergence study is carried out and presented for different harmonics. The numerical results obtained are also first validated with existing literature for their accuracy. © 2013 Elsevier Ltd.

Desai P.,Navrachana University | Desap F.,Private Practitioner | Patil H.,SVNIT
Gazzetta Medica Italiana Archivio per le Scienze Mediche | Year: 2016

In this paper, we imitate human bone (anil bones) as structural beam for the analysis. Realistic cross sections of the three human arm bones (radius, ulna and humerus) considered from the real specimens. Bone as complex biological structures is converted mto the simple structure which may be analyzed with an ease by existing theory. Modeling of human arm bones and hypotheses used in this paper are purely mathematical and they represent the assumptions of classical and Timosheiiko beam theories. Findings of this paper give the realistic strength of the normal human arm bones and assessments of the load that a normal human being can take. Deflection analysis is carried out for various loading conditions such as axial, bending, torsion and shear cases when the cross section is non prismatic and irregular in shapes through the length of the bone. © 2014 Edizioni minerva medica.

Singh M.P.,Navrachana University | Jain M.K.,Mohanlal Sukhadia University
2015 International Conference on Pervasive Computing: Advance Communication Technology and Application for Society, ICPC 2015 | Year: 2015

Instruction set architecture (ISA) of a processor fills the semantic gap between user and machine. A good ISA for a particular application should be able to address the issues of programmability, implementability, and compatibility. An application specific instruction set processor (ASIP) is a processor designed for a particular application. ISA customization is the process of integrating application specific ISEs (Instruction Set Extensions) into an ASIP's instruction set architecture. ISA customization pose a major challenge in realizing deigns for application specific processors. This paper is an attempt to investigate contemporary instruction set architectures and to identify issues in ISA customization for application specific instruction set processors. © 2015 IEEE.

Kumar S.,M. S. University of Baroda | Patel H.,M. S. University of Baroda | Patil S.R.,M. S. University of Baroda | Patil S.R.,Navrachana University
Colloid and Polymer Science | Year: 2013

Phenomenon of clouding in charged micellar solutions is a fairly recent addition to conventional phenomenon shown by aqueous nonionic micelles. In this paper, we have tested a Hofmeister-like ordering of charged headgroups in the context of cloud point (CP) and micellar growth. For this purpose, we have used various combinations of surfactant (sodium dodecyl sulfate, SDS; sodium dodecylbenzene sulfonate, SDBS; sodium salts of α-sulfonato myristic acid methyl ester, MES; and α-sulfonato palmitic acid methyl ester, PES) and tetra-n-butylammonium bromide (TBAB). Different surfactant concentrations and TBAB concentrations are used and CP measurements have been performed. CP values were found in the order SDBS < SDS < PES < MES for the same concentration of surfactant and TBAB. This order has been discussed in the light of water affinities of interacting ionic species (i.e., surfactant headgroup and TBA+ counterion). The ordering was found similar for the case of micellar growth studied by dynamic light scattering (DLS). A bimodal distribution of aggregate size was found that transforms to giant aggregates at CP. The micelles of roughly 10-nm size convert to aggregates of 1 μm. The study has a few novelties: (1) headgroup dependence of CP, (2) micellar growth on heating, and (3) confirmation of Hofmeister-like series of headgroup. © 2013 Springer-Verlag Berlin Heidelberg.

Desai P.,Navrachana University | Kant T.,Indian Institute of Technology Bombay
Journal of Sandwich Structures and Materials | Year: 2015

Numerical analysis is carried out in this paper for thick circular cylindrical shells using higher order shell theory. In orthogonal curvilinear coordinate system, all equations are derived with the inclusion of the additional quadratic and cubic terms in the Taylor’s series expansions of the both in-plane as well as the transverse displacement components for the improvement of bending behaviour of the shell. Assuming (h/R)2 ≪ 1, a rigorous formulation involving the reduction of a three-dimensional elasticity problem to a two-dimensional one, based partly upon the Reissner’s variational principle, is presented. These equations are algebraically manipulated to be in the form of a coupled system of first-order differential equations in terms of the intrinsic dependent variables. These are then solved by a segmentation method – numerical integration technique for various combinations of material and geometric parameters. The theory is shown to result in a partial differential equation system of sixteenth order. © The Author(s) 2014 Reprints and permissions:

Yadav P.,Navrachana University | Purohit N.V.,M. S. University of Baroda
Journal of Chemical Sciences | Year: 2013

Some new 3,4-disubstituted isocoumarins were synthesized having bioactive pyrazole molecule at 3rd position of isocoumarin moiety (5a,b), from isocoumarin -3- carboxylic acid hydrazide (4a,b) followed by cyclization with acetyl acetone. A series of isocoumarin derivative having Schiff base as lateral side chain at 3rd position of isocoumarin moiety were also synthesized (7a,b), by condensing isocoumarin acid hydrazide and benzaldehyde derivative followed by dehydration. The chemical structures of all the compounds were determined by analytical and spectral method. The lead compounds were screened for antimicrobial and analgesic activities. © 2013 Indian Academy of Sciences.

Koppula P.K.,Navrachana University | Purohit N.,M. S. University of Baroda
Journal of Chemical Sciences | Year: 2013

The aim of the present study was to synthesize isocoumarin heterocycles and to elucidate the potential role of these compounds as biological active agents. A new series of isocoumarin derivatives containing two six-membered lactone rings is reported. 3-Aroyl-substituted isocoumarins (3) obtained by condensing 2- carboxy benzaldehyde (1) with bromoacetophenone derivatives (2) was further reacted with different aromatic aldehydes (4) affording bis-(1H-2-benzopyran-1- one) derivatives (5). This short review compiles examples of most promising antibacterial, antifungal and analgesic bis-(1H-2-benzopyran-1-one) derivatives. The products were characterized on the basis of analytical and spectral (IR, 1HNMR, C13NMR, Mass) data. The biological activity study revealed that all compounds showed promising activities and bis-(1H-2-benzopyran-1-one) derivatives (5) were found to be more active than 3-aroyl-substituted isocoumarins (3). © Indian Academy of Sciences.

Koppula P.,Navrachana University | Purohit N.,M. S. University of Baroda
Organic Communications | Year: 2013

With the aim of developing potential antimicrobial agents, a series of triazolo / tetrazolo isoquinolines incorporating both nitrogen and oxygen as part of the hetero aromatic ring were prepared from 4-alkyl-3-aroyl isocoumarins via a number of intermediate steps. Some novel coumarinoyl derivatives of isocoumarins were also synthesized starting from 4-alkyl-3-aroyl isocoumarin and characterized by FTIR, 1H NMR, Mass Spectroscopy and elemental analysis. All the title compounds 7a,b, 8a,b, 10a-g were evaluated for their antibacterial activity against S. Aureus (as gram positive), E. Coli (gram negative bacteria) and antifungal activity against Fusarium pallidoroseum & Chaetonium in vitro and analgesic activity which was tested in vivo on mice. Most of the compounds showed appreciable results for all the three activities. The relationship between the functional group variation and biological activity of the evaluated compound is discussed. The new compounds emerged as potential molecule for further development. © 2013 ACG Publications.

Badgujar A.D.,Indian Institute of Technology Bombay | Badgujar A.D.,Navrachana University | Naik H.B.,Sardar Vallabhbhai National Institute of Technology, Surat | Atrey M.D.,Indian Institute of Technology Bombay
Physics Procedia | Year: 2015

Research on Stirling type Pulse Tube Cryocooler (PTC) is focused on achieving lower temperatures by cascading the stages or by multi-staging. Multi-staging can be done either by gas coupling or by thermal coupling of the stages. In the thermal coupling option, either a two stage cooler can pre-cool a single stage PTC to reach lower temperatures or a single stage PTC can cool a two stage PTC. In the present work, both these configurations are tested experimentally keeping the same two stage PTC. In case-1, the two stage PTC is used as a pre-cooling stage while in case-2, the single stage PTC is used as a pre-cooling stage. Length of the single stage is required and to be increased to match the two stages PTC for effective thermal coupling in case-1. The lowest temperature achieved in case-1 is 50.07 K where as in case-2 the lowest temperature achieved is 19.61 K at 17 bar charge pressure and 68 Hz frequency. The pressure drop in both the PTCs is compared to analyze the difference in performance. © 2015 The Authors.

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