Bhāvnagar, India
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Maniya K.D.,Veer Narmad South Gujarat University | Bhatt M.G.,Bhavnagar University
Computers and Industrial Engineering | Year: 2011

In the present work, a systematic and an alternative multiple attribute decision making methodology is presented for selection of facility layout design selection problems. The proposed methodology is based on Preference selection index (PSI) method. In the proposed methodology appropriate facility layout design is selected for a given application without considering relative importance between facility layout design selection attributes. Two different types of facility layout design selection problems are examined to demonstrate, validate, and to check the reliability of proposed methodology. In addition, subjective cost benefit analysis is performed to study the benefits to cost to the company. Finally, the study has concluded that the facility layout design selection methodology based on PSI method is simple, logical, and more appropriate for solving the facility layout design selection problems. © 2011 Elsevier Ltd. All rights reserved.

Maniya K.D.,Veer Narmad South Gujarat University | Bhatt M.G.,Bhavnagar University
International Journal of Production Research | Year: 2011

The objective of this research is to develop and implement a new methodology for multi-attribute selection of automated guided vehicle (AGV) for the material handling. The present paper proposes a modified grey relational analysis (M-GRA) method combined with analytical hierarchy approach (AHP). AHP method is used to assign the relative importance between AGV selection attributes and M-GRA method is applied to determine AGV selection utility index. A proposed AHP/M-GRA technique is more suitable for the decision-making in the presence of vagueness. The methodology is illustrated by means of an example. The study was followed by the validation and the sensitivity analysis of the AHP/M-GRA technique. The results of the study build confidence in suitability of AHP/M-GRA technique for selection of AGV alternatives. © 2011 Taylor & Francis.

Vala A.K.,Bhavnagar University | Sutariya V.,Shree Dhanvantary Pharmaceutical and Research Institute
Jundishapur Journal of Microbiology | Year: 2012

Background: Facultative marine fungi could potentially be arsenic tolerant and may be able to remove this highly poisonous metal from the environment. Objectives: The objective of this work was to explore the degree of tolerance and removal efficiency of two facultative marine fungi. Materials and Methods: Facultative marine fungi Aspergillus flavus and Rhizopus spp. were exposed to 25 mg/L and 50 mg/L sodium arsenite (As (III)). Tolerance of these species to the test concentrations was assessed by studying their biomass accumulation. Accumulation of arsenic by the fungal biomass was also evaluated. Results: Our study revealed that both A. flavus and Rhizopus sp. exhibited tolerance towards the test concentrations of arsenic. Both of the test fungi also exhibited arsenic accumulation. Rhizopus sp. was found to be a slightly better potential accumulator. Conclusions: This study reveals that the test fungi can be harnessed as bioremediation agents for arsenic contaminated sites. © 2012 Ahvaz Jundishapur University of Medical Sciences; Published by Kowsar Corp.

We review here, our work on the light scattering by ferrofluids and mixture of ferrofluids and other nonmagnetic suspensions subjected to an external static magnetic field. Detailed derivation of extinction coefficients of the systems when incident light is propagating along transverse and longitudinal direction of the field are carried out. In case of inclusion of anisotropic diamagnetic micron sized particles in a ferrofluids, effects of'magnetic holes' generated in the system on the extinction are discussed. The present work is analyzed in light of other similar investigations. It is shown that the study of polarization dependence of extinction coefficients in transverse field configuration is useful to arrive at an unambiguous conclusion regarding chain formation in a ferrofluid. © 2013 Elsevier B.V. All rights reserved.

In this article, we have described the conventional and microwave method for the synthesis of 1-[2-(2-chloro(3-quinolyl))-5-(4-nitrophenyl)(1,3,4- oxadiazolin-3-yl)]-3-(aryl)prop-2-en-1-ones (4a-l). Through this method, we have achieved reduction in reaction time and better yield than the previously described conventional method. The application of microwave irradiation (MWI) is used for carrying out chemical transformations which are pollutionfree and eco-friendly. The structure of the compounds was characterized by spectral data. These compounds (4a-l) were evaluated for their in vitro antimicrobial screening on different strains of bacteria and fungi. © Springer Science+Business Media, LLC 2011.

Patel R.,Bhavnagar University | Mehta R.V.,Bhavnagar University
EPJ Applied Physics | Year: 2010

We show here that at a certain externally applied static magnetic field of moderate value, photonic band gap (PBG) is induced at optical frequencies in a stable colloidal dispersion containing a mixture of micron and nano sized magnetite spheres. The PBG is found to depend on the size of microspheres and is observed for only TM mode of the incident waves. Effect of nonmagnetic doping on the PBG is also discussed. The observed effects are attributed to the magnetically induced morphological dependent resonance (MDR) in the micron sized magnetic spheres. The technique to induce PBG may be easily amenable for lab-on-chip devices. © 2010 EDP Sciences.

Bhatt H.,Bhavnagar University | Patel R.,Bhavnagar University | Mehta R.V.,Bhavnagar University
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2010

Mie scattering functions for a magnetizable sphere whose relative refractive index is dependent on the externally applied magnetic field are computed for four different sizes of the sphere. It is found that Mie resonances are observed at certain critical fields when the incident light is polarized with its electric vector perpendicular to the applied field. The width of resonance as well as the critical fields shifts with the increase in size of the spheres. Results are compared with the experimentally observed scattering effects in a dispersion of magnetite spheres in a ferrofluid. © 2010 Optical Society of America.

Patel R.,Bhavnagar University
Journal of Magnetism and Magnetic Materials | Year: 2011

Mechanism of structure formation in bidispersed colloids is important for its physical and optical properties. It is microscopically observed that the mechanism of chain formation in magnetic nanofluid based magnetorheological (MR) fluid is quite different from that in the conventional MR fluid. Under the application of magnetic field the magnetic nanoparticles are filled inside the structural microcavities formed due to the association of large magnetic particles, and some of the magnetic nanoparticles are attached at the end of the chains formed by the large particles. The dipolar energy of the large particles in a magnetic nanofluid matrix becomes effective magnetic permeability (μeff) times smaller than that of the neutral medium. Inclusion of magnetic nanoparticles (∼10 nm) with large magnetic particles (∼35 μm) restricts the aggregation of large particles, which causes the field induced phase separation in MR fluids. Hence, nanofluid based MR fluids are more stable than conventional MR fluids, which subsequently increase their application potentiality. © 2010 Elsevier B.V. All rights reserved.

Jha P.K.,Bhavnagar University | Gupta S.D.,Bhavnagar University | Gupta S.K.,Bhavnagar University
AIP Advances | Year: 2012

A first principles calculation of the lattice dynamical properties of superconducting MgCNi3 has been performed using density functional perturbation theory (DFPT). The calculated phonon dispersion curves and phonon density of states have been compared with inelastic x-ray scattering (IXS) and inelastic neutron scattering (INS) measurements. We show for the first time that phonon dispersion curves for MgCNi3 in whole Brillouin zone are positive (stable phonon modes) and in good agreement with the experimental data. The phonon DOS shows absence of phonon density of states at zero energy unlike earlier calculations. There is a good agreement between calculated and experimental electron-phonon parameter and superconducting transition temperature. The Eliasberg function is quantitatively as well as qualitatively different from the phonon density of states. The lattice specific heat and Debye temperature do not show any anomalous behaviour. Copyright © 2012 Author(s).

Patel R.,Bhavnagar University | Mehta R.V.,Bhavnagar University
Applied Optics | Year: 2011

A ferrodispersion, which comprises micrometer-sized magnetizable spheres dispersed in a ferrofluid, is shown to store retrievable optical energy. It is observed that when such dispersion is subjected to a transverse magnetic field and a linearly polarized monochromatic light with its electric vector perpendicular to the applied field is incident on it, then for a critical static magnetic field of moderate intensity the emerging light disappears. Upon removing the light and then switching off the field, again light of the same frequency and same state of polarization reappears. A time delay between emission of the light and switching off the field is observed. The statistical distribution of this delay is reported. Intensity of the retrieval signal is found to depend on the storage time. This effect is investigated. Storing and retrieval of optical energy will be useful for developing a magnetically tunable optical capacitor. © 2011 Optical Society of America.

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