Showing papers by "University of Rajasthan published in 1987"

Haematological and haematopoietic response to acid stress in an air‐breathing freshwater fish, Channa punctatus Bloch

Abstract: Response of Channa punctatus to acidic water was studied by exposing fishes to pH 3.5, 4.5, 5.5 and 6.5 for 6 weeks. Growth and mortality data indicated increasing stress as the acid level in the ambient water increased. While no mortality was recorded at pH 6.5, a distinct loss of weight compared to continuous gain in body weight in control fish indicated stress. As the pH level decreased, the rate of loss in body weight increased accompanied by mortality which rose to as high as 60% within 3 weeks in fishes exposed to water at pH 3.5. Haematological investigations confirmed the general stress indicated by growth and mortality data. Thus. RBC and related values indicated overall polycythemia. However, eosinophils, basophils. and large and small lymphocytes showed a distinct fall in number as compared to the control. Correlated haematopoietic studies revealed that both the initial and penultimate stages in RBC and neutrophil development recorded an increase parallel to that observed in peripheral blood, but intermediate stages, probably because they were unable to keep pace with the fast turnover, showed a relative decrease. Biochemical investigations showed an increase not only in blood glucose level but also in liver glycogen content. However, there was a significant decrease in muscle glycogen reserves. The significance of these changes is discussed.

Synthesis and Characterization of Silicon(IV) Complexes of Semicarbazones and Thiosemicarbazones

Abstract: Equimolar reactions of trimethyl chlorosilane and Schiff bases having the donor groups NSH or NOH have yielded penta-coordinated trimethylsilicon Schiff base derivatives. The resulting complexes of the type Me3 SiL (where LH = monofunctional bidentate semi- and thiosemicarbazones) have been characterized on the basis of elemental analyses, molecular weight determinations, conductivity measurements and electronic spectral studies. Their trigonal bipyramidal geometry has been discussed on the basis of IR, 1H NMR and 13C NMR spectral studies.

Antimicrobial activity of pyrrolizidine alkaloids from Heliotropium ellipticum.

Abstract: Pyrrolizidine alkaloids, known for their significant antitumor activity, have been isolated from the aerial parts of H. ellipticum LEDEB. Europine (0.120%), heliotridine (0.152%), lasiocarpine (0.136%) and lasiocarpine-N-oxide (0.090%) have been identified. Antimicrobial activity of the isolated alkaloids against selected pathogenic bacteria and fungi has been investigated for the first time.

Coordination compounds of chromium(III) with semicarbazones and thiosemicarbazones of heterocyclic aldehydes

Abstract: [CrCl3(thf)3] (thf=tetrahydrofuran) reacts with semicarbazones and thiosemicarbazones to yield adducts of the type, [CrCl3L] and [CrCl3L2] (where L=semicarbazones or thiosemicarbazones of furfuraldehyde and indole-3-carboxaldehyde). I.r. data suggest that L bind via the azomethine nitrogen and oxygen/sulphur. Magnetic studies and lig-and field parameters suggest a tetragonal structure for these complexes.

A gravitationally non-degenerate cosmological model with expanding and shearing viscous fluid in general relativity

Abstract: The object of this paper is to investigate the behaviour of viscosity in a cosmological model, in which the coefficient of shear viscosity is assumed to be proportional to rate of expansion in the model. The behaviour of the model in the absence of shear viscosity is also discussed.

Calculation of thermal efficiency of salt gradient solar ponds

Abstract: The three-zone salt gradient solar ponds are theoretically analysed taking them as steady state flat plate collectors. A numerical model has been developed to determine the thermal efficiency of a salt gradient solar pond under different operating conditions. The model simulates the thicknesses of the upper convective zone, non-convective zone and lower convective zone, convective and radiation losses from the surface, heat loss to the atmosphere due to evaporation, upward heat conduction and ground (bottom and side) heat losses from the pond. Numerical calculations are made using expression derived for heat losses from a flat-bottomed cylindrical solar pond, to investigate the optimization of geometrical and operational parameters of the solar pond. Calculations have also been done for the heat losses from the pond for different insulating materials at the bottom and the sides of the pond. The use of different insulating materials at the bottom and the side of the pond shows that dry marble dust is a better insulator to increase a thermal efficiency of the pond.

Long-term vasectomy effects on testis and accessory sex organ function in langur monkey.

Abstract: Testicular biopsy, serum and semen samples from bilaterally vasectomized and sham-operated langur monkeys were studied following 1.5, 2.0 and 2.5 years of surgery to assess testis and accessory sex organ function. Testicular degeneration was evident in certain tubules. Circulating levels of serum testosterone were statistically unchanged. Seminal plasma concentrations of fructose, acid phosphatase, sodium and potassium did not change, whereas semen volume, LDH, magnesium and citric acid decreased significantly suggesting an altered prostatic function following longer durations of vasectomy.

Renormalized-free-atom model and Compton profile of hcp cobalt

Abstract: Compton profile of cobalt has been calculated employing the renormalized-free-atom model for fcc as well as hcp phases choosing several 3d-4s configurations. The results have been compared with recent gamma-ray measurements on polycrystalline Co. Best agreement between theory and experiment is found for 3d74s2 configuration. Comparison with free electron model has also been made for this case.

Coordination behaviour of benzothiazolines towards iron(II)

Abstract: This paper describes the synthesis and structural features of iron(II) complexes of some biologically active benzothiazolines derived by the condensation of various aldehydes and ketones such as pyridine 2-aldehyde, furfuraldehyde, thiophene-2-aldehyde, indole-3-carboxaldehyde, benzil, biacetyl, glyoxal, and terpthaldehyde with 2-aminothiophenol. An attempt has been made to characterize the resulting complexes by elemental analysis, conductance measurement, molecular weight determination and electronic, infrared,1H and13C n.m.r. spectral studies. An octahedral geometry has been suggested on the basis of magnetic measurements and Mossbauer spectra.

Likelihood Ratio Test for Multisample Sphericity

Abstract: This article deals with the null and nonnull distributions of the likelihood ratio criterion for testing multisample sphericity in q multinormal populations. Nonnull moments have been obtained using a simple and shortcut method. The null density has been derived using inverse Mellin transform and the calculus of residues. The nonnull density is given in a series involving zonal polynomials and generalized hypergeometric functions.

Silicon position sensitive detectors for the helios (NA 34) experiment

Abstract: Silicon detectors having both “pad” and strip position sensitive configurations have been fabricated for the Helios experiment which requires an elaborate pulse height-dependent trigger as well as one dimensional silicon strip position sensing. The trigger detector is a 400 element, 30 mm diameter detector with readout connections from a ceramic overlay board. Tests with full prototype detectors have shown essentially 100% detection efficiency and excellent pulse height resolution well capable of delineating 0, 1 or 2 hits per pad. Strip detectors with 25 μm pitch and a varying readout pitch have been tested, which utilize both capacitive and resistive charge division. Techniques for realization of required interstrip resistors will be discussed and results which may compare these readout methods will be reported.

Nonnull distribution of the likelihood ratio criterion for testing equality of covariance matrices under intraclass correlation model

Abstract: The nonnull moments of the likelihood ratio statistic for testing equality of covariance matrices under intraclass correlation structure are obtained in terms of the Lauricella's hypergeometric functions and also in terms of zonal polynomials. Then the nonnull asymptotic distribution of the statistic is derived for certain alternatives.

Inhomogeneous cosmological models with electromagnetic field in general relativity

Abstract: In this paper inhomogeneous cosmological models with perfect fluid distributions in presence of electromagnetic field is obtained. Various physical and geometrical properties of the model in presence of electromagnetic field are also discussed.

Synthesis and Characterization of Mixed Azomethine Derivatives of Silicon(IV)

Abstract: Synthesis and characterization of mixed azomethine derivatives of silicon(IV) with anils and thio-anils have been described. Such derivatives of the type (ONO)Si(ONS) in which ONO and ONS represent the donor sets of two different bifunctional tridentate azomethines, have been prepared by 1:1:1 molar reactions of silicon tetraacetace with equimolar amounts of the ligands. These are obtained as coloured solids and behave as non-electrolytes in dry DMF. Suitable hexa-coordinated structures based on elemental analysis, molecular weight determinations, conductance measurements and infrared and proton magnetic resonance spectral studies have been indicated for these derivatives.

Synthesis of Biologically Active Lead (II and IV) Complexes of Schiff Bases Derived from Sulpha Drugs

Abstract: The present paper describes the synthesis and structural features of the lead complexes with Schiff bases derived from sulpha drugs. The resulting complexes have been subjected to elemental analyses, conductance measurements, molecular weight determination and electronic, infra-red and proton nuclear magnetic resonance spectral studies and their plausible structures have been discussed. A few representative complexes have also been screened for their fungicidal as well as bactericidal activity and found to be quite active in this respect.

Inhomogeneous viscous fluid cosmological model with electromagnetic field in general relativity

Abstract: The object of this paper is to investigate the behaviour of electromagnetic field in inhomogeneous cosmological models obtained for viscous fluid distributions. The various particular cases when both the electromagnetic and viscosity are absent, are also discussed.

Study of AsGeSe Structures by positron lifetime technique

Abstract: The positron lifetimes in amorphous samples of sloichiometric compositions As x Ge 50 − x Se 50 ( x = 20, 25, 35) have been measured using the conventional fast-slow coincidence method. The lifetime spectrum is resolved into two components τ 1 , and τ 2 having intensities as high as 70 and 30% respectively. This indicates the existence of two different average electron density regions in these materials. The annealing of these substances leads, as expected, to a reduction in I 2 but to an unexpected increase in both τ 1 and τ 2 . The changes in I 2 have been correlated with the changes in degree of amorphous nature of the samples and it is shown that positron lifetime parameters can be used to characterise the amorphous materials. The increase in magnitude of τ 1 and τ 2 is explained on the basis of point charge defects of C 1 − and T 3 − type present in these materials.

Mixed Ligand Complexes of Alkaline Earth Metals. III. Mg(II) and Ca(II) Complexes of 1-Phenylbutane-1, 3-Dione and Salicylaldehyde, 2-Hydroxyacetophenone, 2-Hydroxypropiophenone or Pentane-2, 4-Dione

Abstract: Reactions of Mg(II) and Ca(II) chlorides with two carbonyl compounds (HL and HL′) in 1:1:1 molar ratio in ethanol have yielded mixed ligand complexes [MLL′(H2O)2] (where M = Mg(II) or Ca(II) and HL is 1-phenylbutane-1,3-dione and HL′ is salicylaldehyde, 2-hydroxyacetophenone, 2-hydroxypropiophenone or pentane-2,4-dione). These complexes have been characterized by elemental analyses, TLC, IR, electronic and NMR spectra.

Metal and organometal complexes of oxy-and thiophosphorus acids. part ii. reactions of o,o-alkylene dithiophosphoric acids with titanium(iv) isopropoxide

Abstract: Replacement reactions of titanium(IV) isopropoxide with O,O-alkylene dithiophosphoric acids proceed in 1:1 and 1:2 molar ratios in refluxing benzene to yield tri-and diisopropoxytitanium alkylene dithiophosphates, (n = 1 and 2; G = °CMe2CMe2[sbnd], [sbnd]CH2CMe2CH2[sbnd], [sbnd]CH2CEt2CH2[sbnd], and [sbnd]CHMeCHMe[sbnd]) as hydrolysable, orange solids or viscous liquids, soluble in common organic solvents and monomeric in nature. Further replacement of isopropoxy groups to give tris and tetrakis dithiophosphates does not occur. The isopropoxy groups in the mixed derivatives, however, can be replaced by tert-butoxy groups. All these compounds have been characterized by elemental analyses, molecular weight determinations and IR and NMR (1H, 13C and 31P) spectral data which are consistent with bidentate chelating behaviour of the dithiophosphate ligands.

Trichlorooxovanadium(V) derivatives of thio-Schiff bases

Abstract: The synthesis and characterization of five- and six-coordinate oxovanadium(V) complexes of the type [(VOCl2)(TSCZ)] and [(VOCl)(TSCZ)2] (where HTSCZ represents thiosemicarbazones of furfuraldehyde, pyridine-2-aldehyde, thiophene-2-aldehyde and cinnamaldehyde) are reported. On the basis of i.r., u.v.,1H and13C n.m.r. spectral studies, distorted trigonal bipyramidal and octahedral geometries are proposed for [(VOCl2)(TSCZ)] and [(VOCl)(TSCZ)2], respectively.

Thermal characteristics and performance of salt gradient solar ponds

Abstract: A mathematical model with various parameters such as effective absorptivity-transmitivity product and total heat loss factor, including ground losses and angle of refraction, which are related to the physical properties and dimensions of the pond, is developed to study the thermal behaviour of salt gradient solar ponds at different operational conditions. A linear relation is found between the efficiency of the solar pond and the function (ΔT/H). The convective heat loss, the heat loss to the atmosphere due to evaporation through the surface of the pond and ground heat losses have been accounted for in finding out the efficiency of the pond. The dependence of the thermal performance of the solar pond on the ground heat losses is investigated and minimized using low cost loose and insulating building materials such as dry dunes and, Mica powder and loose asbestos at the bottom of the pond. The ground heat losses are considerably reduced with the asbestos (loose) and the retention power of solar thermal energy of the pond increases.