592,068 research outputs found

    The pressure of deconfined QCD for all temperatures and quark chemical potentials

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    We present a new method for the evaluation of the perturbative expansion of the QCD pressure which is valid at all values of the temperature and quark chemical potentials in the deconfined phase and which we work out up to and including order g^4 accuracy. Our calculation is manifestly four-dimensional and purely diagrammatic -- and thus independent of any effective theory descriptions of high temperature or high density QCD. In various limits, we recover the known results of dimensional reduction and the HDL and HTL resummation schemes, as well as the equation of state of zero-temperature quark matter, thereby verifying their respective validity. To demonstrate the overlap of the various regimes, we furthermore show how the predictions of dimensional reduction and HDL resummed perturbation theory agree in the regime T~\sqrt{g}*mu. At parametrically smaller temperatures T~g*mu, we find that the dimensional reduction result agrees well with those of the nonstatic resummations down to the remarkably low value T~0.2 m_D, where m_D is the Debye mass at T=0. Beyond this, we see that only the latter methods connect smoothly to the T=0 result of Freedman and McLerran, to which the leading small-T corrections are given by the so-called non-Fermi-liquid terms, first obtained through HDL resummations. Finally, we outline the extension of our method to the next order, where it would include terms for the low-temperature entropy and specific heats that are unknown at present.Comment: 45 pages, 21 figures; v2: minor corrections and clarifications, references added; v3: Fig 16 added, version accepted for publication in PR

    Cu(II) and Fe(III) complexes of sulphadoxine mixed with pyramethamine: Synthesis, characterization, antimicrobial and toxicology study

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    Two new mixed ligands metal complexes of sulphadoxine and pyramethamine were prepared by using CuCl2.6H2O and FeCl3.6H2O. The complexes were characterized by elemental analysis, melting point determination, molar conductivity, metal content analysis (AAS), IR, magnetic susceptibility measurements and UV-Visible spectroscopy. Based on the analytical and spectroscopic data, the complexes were proposed to have the formulae [M1L1L2(Cl)2] and [M2L1L2(Cl)3] (where M1 = Cu(II), M2 = Fe(III)), L1 = sulphadoxine, L2 = pyramethamine). The spectroscopic data proposed L1 to be a monodentate ligand and coordinated through N atom of the NH2 group in both complexes. Also, L2 was proposed to be tridentate ligand and coordinated through N atom of the NH2 groups and through N atom of imine group. However, [M1L1L2(Cl)2] and [M2L1L2(Cl)3] were proposed to possess distorted octahedral geometry. Conductivity measurement values supported the non-electrolytic nature of the complexes. The complexes have been tested in vitro against a number of pathogenic bacteria [g(+) Escherichia coli, g(+) Proteus species, g(+) Pseudomonas aeruginosa and g(+) Salmonella typhi] by using disc diffusion method. Obtained results indicated that the metal complexes exhibited better antibacterial activities as compared to the ligands. Toxicology tests against some tissues of albino rat (Rattus novergicuss) revealed toxicity of the complexes in the kidney as compared to the parent drugs. [M1L1L2(Cl)2] was found to be toxic to the sera, livers and kidneys of the rats used, while [M2L1L2(Cl)3] was found to be non-toxic to the sera, livers and kidneys of the rats as their alkaline phosphatase (ALP) values showed non-significant difference to the control value

    Hydrodynamics of Monolayer Domains at the Air-Water Interface

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    Molecules at the air-water interface often form inhomogeneous layers in which domains of different densities are separated by sharp interfaces. Complex interfacial pattern formation may occur through the competition of short- and long-range forces acting within the monolayer. The overdamped hydrodynamics of such interfacial motion is treated here in a general manner that accounts for dissipation both within the monolayer and in the subfluid. Previous results on the linear stability of interfaces are recovered and extended, and a formulation applicable to the nonlinear regime is developed. A simplified dynamical law valid when dissipation in the monolayer itself is negligible is also proposed. Throughout the analysis, special attention is paid to the dependence of the dynamical behavior on a characteristic length scale set by the ratio of the viscosities in the monolayer and in the subphase.Comment: 12 pages, RevTeX, 4 ps figures, accepted in Physics of Fluids

    Comparative study of microwave assisted and conventional synthesis of novel 2-quinoxalinone-3- hydrazone derivatives and its spectroscopic properties

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    A series of novel quinoxalin-2(1H)-one-3-hydrazone derivatives, 2a - 8d were synthesized via condensation of 3-hydrazinoquinoxalin-2(1H)-one, 1, with the corresponding ketones under microwave irradiation. The microwave assisted reaction was remarkably successful and gave hydrazones in higher yield at less reaction time compared to conventional heating method. The chemical structures of the compounds prepared were confirmed by analytical and spectral dat

    HISTOLOGICAL STUDIES OF BREWERY SPENT GRAINS IN DIETARY PROTEIN FORMULATION IN DONRYU RATS

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    The increasing production of large tonnage of products in brewing industries continually generates lots of solid waste which includes spent grains, surplus yeast, malt sprout and cullet. The disposal of spent grains is often a problem and poses major health and environmental challenges, thereby making it imminently necessary to explore alternatives for its management. This paper focuses on investigating the effects of Brewery Spent Grain formulated diet on haematological, biochemical, histological and growth performance of Donryu rats. The rats were allocated into six dietary treatment groups and fed on a short-term study with diet containing graded levels of spent grains from 0, 3, 6, 9, 12 and 100% weight/weight. The outcome demonstrated that formulated diet had a positive effect on the growth performance of the rats up to levels of 6% inclusions, while the haematological and biochemical evaluation revealed that threshold limit should not exceed 9% of the grain. However, the histological study on the liver indicated a limit of 3% inclusion in feed without serious adverse effect. Thus invariably showing that blend between ranges 1-3% is appropriate for the utilization of the waste in human food without adverse effect on the liver organ. The economic advantage accruing from this waste conversion process not only solves problem of waste disposal but also handle issues of malnutrition in feeding ration

    Synthesis, physical properties, antimicrobial potentials of some mixed antibiotics complexed with transition metals and their effects on alkaline phosphatase activities of selected rat tissues

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    Mixed ligand metal complexes of chloramphenicol and oxytetracycline were prepared by using Ni(II), Co(II) and Fe(III) metal chloride hexahydrate. They were characterized based on some physical technique and spectroscopic analysis such as AAS, UV, and IR spectroscopy. Based on the analytical and spectroscopic data, the complexes were proposed to have the formulae [ML1L2](Cl)n (where M = Ni(II), Co(II), Fe(III); L1 = chloramphenicol, L2 = oxytetracycline and n = 2 - 3). IR spectra suggested that both L1 and L2 coordinated to the metal ions in a terdentate manner with ďż˝(O-H), ďż˝(C=O) and ďż˝(N-H) as donor sites in each of the ligands. The complexes were proposed to be of octahedral. The synthesized complexes, in compares to their ligands, were screened for their antibacterial activity against isolated strains of Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia by using diffusion method. The activity data showed the metal complexes to be more potent antibacterial than the parent drugs against the three species. Toxicology tests against some tissues of albino rat (Rattus novergicuss) revealed toxicity of the complexes as compared to the parent drugs. Ni(II) complex was found to possess no significant difference (P > 0.05) in alkaline phosphatase from both homogenates of liver and kidney and rat serum. However, Co(II) and Fe(III) complexes were found to significantly increase (P < 0.05) alkaline phosphatase from homogenates of liver and kidney tissues of the tested doses but there was no significant difference (P > 0.05) in alkaline phosphatase from rat serum

    PROCESSING OF TRIGLYCERIDES TO DIESEL RANGE HYDROCARBON FUELS: EASILY PRACTICABLE SMALL SCALE APPROACH

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    Lipid fraction of biomass has been identified as carbon neutral substitution to fuels from fossil sources in the transportation sector. Although, the diesel engine, invented by Rudolph Diesel over a century ago first ran on peanut oil, the current combustion engines are designed to run on hydrocarbon fuels derived from petroleum. Therefore, a substitute for diesel fuel from renewable source will need to have identical or closely similar properties. The most popular of the existing technology for processing vegetable or animal oils is based on the conversion of the triglycerides constituents to fatty acids methyl esters (FAME). FAME technology does not produce diesel fuel with identical properties as petro-diesel. Other alternative processing routes are dilution of the vegetable oils, emulsification, pyrolysis and hydrotreating. These routes are discussed in this paper. Appropriate technologies for small scale production of diesel range hydrocarbon fuel from vegetable oil without the need for co-reactants such methanol or hydrogen as part of the feedstock is emphased. Also alternative catalyst systems in place of the expensive precious metal supported catalysts are suggested

    Reversible reaction of 5,5V-dithiobis(2-nitrobenzoate) with the hemoglobins of the domestic cat: Acetylation of NH3 + terminal group of the h chain transforms the complex pH dependence of the forward apparent second order rate constant to a simple form

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    We demonstrate kinetically that the reaction of 5,5V-dithiobis(2-nitrobenzoate) with the CysF9[93]h sulfhydryl group of domestic cat hemoglobins is a reversible process. In the major hemoglobin, in which the NH3 + terminal group of GlyNA1[1]h is free, kf, the apparent forward second order rate constant, has a complex pH dependence profile. In the minor hemoglobin, the NH3 + terminal group of SerNA1[1]h is acetylated, and the pH dependence profile of kf is simple. These results support the proposal that the positively charged groups at the organic phosphate binding site are electrostatically linked to CysF9[93]h. Quantitative analyses of the complex profiles enabled us to estimate pKas of 7.47T0.3; 6.53T0.03 and 8.49T0.3 for GlyNA1[1]h, HisH21[143]h and other histidines within 2 nm of the sulfhydryl, and CysF9[93]h, respectively, of the major hemoglobin. Analyses of the simple profiles gave pKas of 6.33T0.17 and 8.54T0.5 for HisH21[143]h and other histidines within a distance of 2 nm of the sulfhydryl, and CysF9[93]h of the minor hemoglobin, respectively

    Effect of Different Sulphate Types and Concentrations on Compressive Strength of Periwinkle Shell Ash Blended Cement Concrete

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    The study investigated the compressive strength performance of periwinkle shell ash (PSA) blended cement concrete exposed to sulphate environments. Periwinkle shells were obtained from Ikot Ekpene, Akwa Ibom state, Nigeria; and calcined in a furnace to temperature of 8000C at zero soaking time. Concrete mix of design characteristic strength of 25N/mm2 was adopted as the control. The cement component replaced with PSA at five levels of 0%, 10%, 20%, 30% and 40% were cast, and on hardened exposed to varying concentration of sulphates of magnesium, sodium and calcium at four levels of 0%, 1%, 3% and 5% each for three exposure periods of 62, 92 and 152 days after complete immersion in water for 28 days. Using three replicates in all the tests, a total of 630 cubical (150mm) specimens were cast and tested. The results revealed that compressive strength increased with increase in curing age but decreased as the PSA contents increased. The design compressive strength was attained with 10% PSA content at the age of 28 days. The compressive strength reduction in sulphate solutions was noted to increase significantly (p = 0.005, R2 = 0.995) with increase exposure period and concentration, with the most severe caused by magnesium sulphate and the least by calcium sulphate. The least reduction in compressive strength was experienced with 10% PSA blended cement concrete. Based on the test results the study concluded that 10% PSA content is adequate as supplementary cementitious material for structural concrete to be placed in an aggressive sulphate environment

    Fe(III) and Co(II) complexes of mixed antibiotics: synthesis, characterization, antimicrobial potential and their effect on alkaline phosphatase activities of selected rat tissues

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    Two new mixed ligand metal complexes of Fe(III) and Co(II) chloride hexahydrate salts were prepared using standard methods. Ampicillin trihydrate and oxytetracycline hydrochloride antibiotics were used as ligands. Chemical analysis including conductivity measurements, molecular weight determination and spectroscopic studies were used to propose the geometry and mode of binding of the ligands to metal ions. Both ligands were proposed to coordinate to metal ions in ratio 1:1:1 in the complexes. Each of the ligands acted as terdentate ligand. Inhibition properties as well as toxicity effect of administration of the metal complexes at the dose of 3.33 mg/kg body weight thrice daily for 5 days on the alkaline phosphatase (ALP) activities on rat kidney, liver and serum were evaluated. The inhibitory properties of the complexes were found to be significantly different (P<0.05) at the concentration of 1%(w/v) as compared to each of the ligands. The complexes were found to significantly increase (P0.05) in ALP from liver and kidney sera. The results indicated that more potent compounds with better physical properties and enhanced antimicrobial activities upon complexation have been prepared
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