Showing papers by "Cochin University of Science and Technology published in 1992"
Journal Article•
TL;DR: Despite the constraining technique and the increase in intraoperative blood loss, orthotopic liver transplantation with a reduced-size graft allows us to overcome the shortage of pediatric donors and improve the overall survival rate of children with end-stage liver disease.
88 citations
TL;DR: In this paper, a general method for finding the exact solution for the problem of a particle undergoing diffusive motion in a potential in the presence of a \ensuremath{delta}-function sink of arbitrary position and strength was given.
Abstract: We give a general method for finding the exact solution for the problem of a particle undergoing diffusive motion in a potential in the presence of a \ensuremath{\delta}-function sink of arbitrary position and strength. The solution requires knowledge of the Laplace transform of the Green's function for the motion in the absence of the sink. We find the exact solution for the case of the parabolic potential. This has long been an unsolved problem and is of considerable importance as a model for nonradiative electronic relaxation of a molecule in solution.
56 citations
TL;DR: The optical band gap and thermal diffusivity of bulk Ge x Sb 5 Se 95-x and Ge X Sb 10 Se 90-x glasses have been measured using the photoacoustic technique and anomalous behavior at =2.6 is explained on the basis of changes in the network topology due to the formation and development of layered structure in these glasses.
Abstract: The optical band gap (${\mathit{E}}_{0}$) and thermal diffusivity (\ensuremath{\alpha}) of bulk ${\mathrm{Ge}}_{\mathit{x}}$${\mathrm{Sb}}_{5}$${\mathrm{Se}}_{95\mathrm{\ensuremath{-}}\mathit{x}}$ and ${\mathrm{Ge}}_{\mathit{x}}$${\mathrm{Sb}}_{10}$${\mathrm{Se}}_{90\mathrm{\ensuremath{-}}\mathit{x}}$ glasses have been measured using the photoacoustic technique. The behavior of ${\mathit{E}}_{0}$ and \ensuremath{\alpha} as the mean coordination number 〈r〉 is varied shows a maximum at 〈r〉=2.6. The anomalous behavior at 〈r〉=2.6 is explained on the basis of changes in the network topology due to the formation and development of layered structure in these glasses.
42 citations
TL;DR: Four species of bacteria which included Pseudomonasfluorescens, Vibriocholerae andVibriocosticola were observed to produce glutaminase both as extracellular and intracellular fractions, which were higher in mineral media supplemented with 1% glutamine than in nutrient broth added with or without glutamine.
Abstract: Four species of bacteria which includedPseudomonasfluorescens,Vibriocholerae andVibriocosticola were observed to produce glutaminase both as extracellular and intracellular fractions. Comparatively both the fractions were higher in mineral media supplemented with 1% glutamine than in nutrient broth added with or without glutamine. Extracellular glutaminase production was about 2.6–6.8 times greater than the intracellular production by all the tested strains.
38 citations
TL;DR: In this paper, the stoichiometric polycrystalline In2Se3 thin films have been grown by elemental evaporation on both glass and quartz substrates and the compositions are examined by DAN fluorimetry and X-ray photoelectron spectroscopy (XPS).
Abstract: Stoichiometric polycrystalline In2Se3 thin films have been grown by elemental evaporation on both glass and quartz substrates. The compositions are examined by DAN fluorimetry and X-ray photoelectron spectroscopy (XPS). Structure of the films are characterized by X-ray diffraction. The structure of this α-form of thin films have been determined to be hexagonal. Optimization of the preparative conditions employed for elemental evaporation, helped in preparing monophasic films by the suppression of other phases to a very minor extent. Influence of annealing conditions on the stoichiometry of the films are investigated in detail.
24 citations
TL;DR: A significant increase of various autoantibody levels was observed in the paranoid subgroup of schizophrenics compared with the disorganized subgroup, and IgG and IgA titers were significantly decreased in schizophrenic patients.
Abstract: Autoantibodies reacting with cell constituents other than antinuclear antibodies have seldom been reported in the literature on schizophrenia. Serum of 41 DSM-III-R schizophrenic patients was examined for the presence of various autoantibodies and compared with that of healthy volunteers (n= 10) and hospitalized controls. Titers of IgG, IgA and IgM autoantibodies directed against actin, tubulin, myosin, DNA, thyroglobulin, elastin, albumin, DNA and trinitrophenyl groups were determined using enzyme immunoassay. IgG and IgA titers were significantly decreased in schizophrenic patients. These results contrast with those obtained with various other autoimmune and nonautoimmune diseases in which titers are either unchanged or increased. A significant increase of various autoantibody levels was observed in the paranoid subgroup of schizophrenics compared with the disorganized subgroup. These autoantibodies possess characteristics similar to those of natural autoantibodies, which seem to play several biological roles.
23 citations
TL;DR: In this paper, the thermal degradation of short kevlar fiber-thermoplastic polyurethane (TPU) composites has been studied by TGA and Differential Scanning Calorimetry (DSC).
22 citations
TL;DR: In this paper, the composition dependence of the optical band gap, E0, and thermal diffusivity, α, of As Te Se glasses, prepared by the conventional melt-quenching technique, have been determined using photoacoustic technique which is based on the detection of the acoustic signal produced when a modulated light beam is incident on the sample.
Abstract: The composition dependence of the optical band gap, E0, and thermal diffusivity, α, of As Te Se glasses, prepared by the conventional melt-quenching technique, have been determined using photoacoustic technique which is based on the detection of the acoustic signal produced when a modulated light beam is incident on the sample. The optical band gap is found to decrease with increase in As concentration, whereas thermal diffusivity shows a threshold maximum at 40 at.% of As content which is the stoichiometric compositions of the As Te Se system. The observed behaviour is explained on the basis of chemical bonding between the constituents and the idea of rigidity percolation in covalent random networks.
22 citations
TL;DR: In this article, the effect of prolonged cold storage on muscle adenosine triphosphatase (ATPase) and lactate dehydrogenase (LDH) activities was studied in a variety of fresh water and brackish water fish.
Abstract: The effect of prolonged cold storage on muscle adenosine triphosphatase (ATPase) and lactate dehydrogenase (LDH) activities was studied in a variety of fresh water and brackish water fish. Decrease in enzyme activity was observed in all samples stored frozen (- 20°C) over a period of 180 days. Highly significant negative correlation was observed between enzyme activity and frozen storage period with mullet, pearlspot, milk fish and tilapia. Significant linear correlations were observed between decrease in enzyme activities and other biochemical indices and sensory scores. The results indicated that loss of activities of ATPase and LDH in fish muscle was significantly related to early changes in quality of frozen stored fish.
20 citations
TL;DR: Quinoxaline-2-carboxalideneglycine complexes of iron(III), cobalt(II), nickel (II) and copper(II) complexes were subjected to a systematic TG/DTG analysis as discussed by the authors.
Abstract: Quinoxaline-2-carboxalideneglycine complexes of iron(III), cobalt(II), nickel(II) and copper(II) complexes were subjected to a systematic TG/DTG analysis. The decomposition process consists of two stages for all these complexes. Kinetic parameters were evaluated for each of these stages using the Coats-Redfern equation. The rate of decomposition at the second stage seems to have a bearing on the catalytic effect of the metal oxides formed during this stage.
19 citations
TL;DR: In this article, a low degree of crosslinking has been introduced in the matrix by adding one percent dicumyl peroxide to improve the mechanical properties without adversely affecting the processing characteristics.
TL;DR: In this paper, fracture mechanics parameters such as strain energy release rate, G, Rice's contour integral, J, and fracture toughness, K have also been determined under plain stress conditions.
Abstract: Studies based on fracture mechanics have been made on polyacetal toughened with a synthesized thermoplastic polyurethane. The effects of elongation rate and defects like holes and notches on tensile properties have been investigated. Using three-point bending specimens, fracture mechanics parameters such as strain energy release rate, G, Rice's contour integral, J, and fracture toughness, K have also been determined under plain stress conditions. The mechanical loss from the hysteresis curves, and ductile, brittle fractography using scanning electron microscopy have also been studied.
TL;DR: The study revealed that discrete acid phosphatase, alkaline phosphatases, alpha-naphthyl acetate esterase, and peroxidase-staining subpopulations of haemocytes do exist in L. stagnalis, and that there are differences in distribution, and probable reasons for the observed fluctuations in the distribution of enzymes subsequent to haemolymph extraction are discussed.
Abstract: An enzyme cytochemical, light microscopy study was undertaken to evaluate the effect of haemolymph extraction on distribution of acid phosphatase, alkaline phosphatase, alpha-naphthyl acetate esterase, and peroxidase in haemocytes of Lymnaea stagnalis. The study revealed that discrete acid phosphatase, alkaline phosphatase, alpha-naphthyl acetate esterase, and peroxidase-staining subpopulations of haemocytes do exist in L. stagnalis, and that there are differences in distribution. A high percentage, about 96%, of haemocytes showed positive reaction for peroxidase, the percentage of haemocytes showing activity for alpha-naphthyl acetate esterase, acid phosphatase, and alkaline phosphatase, was about 54, 42, and 34, respectively. Haemolymph extraction by foot retraction, significantly affected enzyme distribution. Whereas distribution of acid phosphatase increased significantly from day 1 to 5 after extraction of haemolymph, that of all other enzymes showed significant decrease from day 1 to 7 depending upon the enzyme. The distribution of all enzymes stabilized by day 8 after extraction of haemolymph. Probable reasons for the observed fluctuations in the distribution of enzymes subsequent to haemolymph extraction are discussed.
TL;DR: In this paper, 1-phenyl-2,4-dithiobiuret and 1-5-diphenyl-1,5-dimethyl-2.4-dimitriourea were used as secondary accelerators in binary systems containing TMTD or CBS in sulfur vulcanization of SBR.
Abstract: The chemical reactions involved when a binary accelerator system is used in rubber vulcanization varies with the systems used. The exact mechanism of these reactions is not fully understood even now. Accelerators in which sulfur is combined as S—S, C—S—C, or S—N are generally inactive at low vulcanization temperatures because of the high thermal stability of their sulfur bonds. But sulfur-containing nucleophiles such as thiourea or its derivatives enable accelerators like TMTD or CBS to operate at lower vulcanization temperature, indicating a nucleophilic reaction mechanism in these vulcanization reactions. But, no conclusive evidence is given for such a postulate. In the present study, 1-phenyl-2,4-dithiobiuret and 1,5-diphenyl-2,4-dithiobiuret, which are more nucleophilic than thiourea but which vary in their nucleophilic reactivity, were tried as secondary accelerators in binary systems containing TMTD or CBS in sulfur vulcanization of SBR. Both the above dithiobiurets were found to reduce the...
TL;DR: In this paper, a method of preparation of strontium sulphide phosphors doped with europium is given, and Nitrogen laser excited fluorescence emission spectra of these phosphors in the visible region are recorded.
TL;DR: In this paper, a polycrystalline stoichiometric Bi2Se3 thin films were prepared by reactive evaporation method and Hall effect measurements showed that the films have a carrier concentration of 1.02 × 1019 cm-3 at room temperature.
TL;DR: In this paper, the authors present a paper on "Polymer Science and Rubber Technology, Cochin University of======Science and Technology" (http://www.cochinu.edu.
Abstract: Dept. of
Polymer Science and Rubber Technology, Cochin University of
Science and Technology
TL;DR: In this article, the effects of modifying blends of polyvinyl chloride (PVC) with linear low density polyethylene (LLDPE) by means of acrylic acid, maleic anhydride, phenolic resins and p-phenylene diamine were investigated.
TL;DR: In this article, an analysis of Josephson tunnel junctions based on the RSJ model with nonlinear damping reveals that crisis is the major mechanism that brings about chaos in the system.
Abstract: An analysis of Josephson tunnel junctions based on the RSJ model with nonlinear damping reveals that crisis is the major mechanism that brings about chaos in the system. Details regarding the transition to chaos from zero-voltage steps and nonzero-voltage steps are discussed. The effect of a DC bias in the transition scenario as well as the evolution of the fractal basin boundaries near the crisis regions are studied.
TL;DR: A review of the present status of studies relating to occurrence of deterministic chaos and its characterization in one-dimensional maps is given in this article, where the authors introduce the nonspecialists into this fascinating world of chaos and give sufficient arguments for clarity of ideas.
Abstract: This paper is a review of the present status of studies relating to occurrence of deterministic chaos and its characterization in one-dimensional maps. As our primary aim is to introduce the nonspecialists into this fascinating world of chaos we start from very elementary concepts and give sufficient arguments for clarity of ideas. The two main scenarios during onset of chaos viz. the period doubling and intermittency are dealt with in detail. Although the logistic map is often discussed by way of illustration, a few more interesting maps are mentioned towards the end.
TL;DR: The complexes resulting from the interaction of a new Schiff base ligand derived from crosslinked polystyrene bound benzaldehyde and 2-aminobenzimidazole with a square planar complex [Co(TPP), and also with tetrahedral complexes [Co (BPBI)2X2] have been isolated and characterized as mentioned in this paper.
Abstract: The complexes resulting from the interaction of a new Schiff base ligand derived from crosslinked polystyrene bound benzaldehyde and 2-aminobenzimidazole with a square planar complex [Co(TPP)] (where TPP = meso-tetraphenylporphyrin), and also with tetrahedral complexes [Co(BPBI)2X2] (where BPBI = 1-benzyl-2-phenylbenzimidazole, X = Cl, Br, or NCS) have been isolated and characterized. The percentages of cobalt and nitrogen in the complexes show that only one Schiff base unit is coordinated to cobalt. Infrared spectra suggest that the bonding of the polymer ligand to cobalt is through the N-3 atom of the benzimidazole moiety. The EPR spectra indicate that all the complexes are in the low-spin state and have a square pyramidal environment around cobalt(II). © 1992 John Wiley & Sons, Inc.
16 Dec 1992
TL;DR: In this paper, the design and performance of a fiber optic sensor working on the principle of evanescent wave absorption are described, and the rate of a standard chemical reaction is determined.
Abstract: The design and performance of a fiber optic sensor working on the principle of evanescent wave absorption are described. Using this sensor the rate of a standard chemical reaction is determined. The measured value is compared with that obtained using a spectrophotometer. I.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Journal Article•
TL;DR: In this article, the results of pickling fish with fruit juices and acetic acid in comparison with the use of acid alone are reported, and the results show that the pickles prepared with tamarind juice along with acid were superior to other pickles in colour, taste and texture.
Abstract: The results of pickling fish with fruit juices and acetic acid in comparison with acetic acid alone are reported. Tamarind juice, lime juice and gooseberry juice were tested for their pickling effect along with acetic acid. The biochemical and microbiological qualities of all the experimental samples remained good throughout the 6 months of study. The pickles prepared with tamarind juice along with acetic acid were superior to other pickles in colour, taste and texture. The pickle prepared using gooseberry juice and acetic acid was poor and unacceptable
TL;DR: In this paper, a diffusion-reaction equation approach was proposed to evaluate the rate constant of the electron transfer from an ion in solution to a metal, assuming that the energy of the orbital on the ion crosses the Fermi energy of a metal.
TL;DR: In this paper, the temperature dependence of the thermal diffusivity of the high-temperature superconductor Bi-Sr-Ca-Cu-O with varying Pb doping levels using a photoacoustic technique was measured.
Abstract: We have measured the temperature dependence of the thermal diffusivity of the high-temperature superconductor Bi-Sr-Ca-Cu-O with varying Pb doping levels using a photoacoustic technique Pb doping stabilizes the superconducting phase around 110 K It is found that above T c thermal diffusivity decreases as the Pb concentration increases whereas below T c it tends to saturate at low Pb concentrations
18 Jun 1992
TL;DR: In this paper, a simple and effective method to reduce the radar cross section (RCS) of a dihedral corner reflector is presented, where the RCS of the reflector loaded with periodic conducting strips over a dielectric sheet is determined experimentally and is compared with that from the reference target.
Abstract: A simple and effective method to reduce the radar cross section (RCS) of a dihedral corner reflector is presented. The RCS of a corner reflector loaded with periodic conducting strips over a dielectric sheet is determined experimentally and is compared with that from the reference target. A typical reduction of 20-30 dB for TE (transverse electric) polarization is shown. The large echo due to the mutual perpendicularity of the two flat surfaces in corner reflector is found to be reduced for TE polarization using the strip grating technique. >
TL;DR: In this paper, the mechanical properties of polyvinyl chloride/linear low density polyethylene have been investigated as a means of reprocessing polymer wastes containing such mixtures, and chlorinated polyethyl ene was found to be a useful additive in such blends for improving their tensile strength and processing behaviour.
Abstract: Methods of improving the mechanical properties of poly(vinyl chloride)/linear low density polyethylene have been investigated as a means of reprocessing polymer wastes containing such mixtures. Chlorinated polyethyl ene was found to be a useful additive in such blends for improving their tensile strength and processing behaviour. Co-crosslinking of the blends by chemical means or by irradiation was also found to improve their strength and stiffness.