877 research outputs found

    Voltammetric determination of tinidazole in pharmaceutical tablets using carbon paste electrode

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    Cyclic voltammetry was used to study the electrochemical behavior of tinidazole at carbon paste electrode. Tinidazole showed an irreversible reduction peak at about -440 mV. The differential pulse voltammetric peak current of tinidazole showed linear dependence on concentration in the range 5.0-200 μM with LOD and LOQ of 5.1 10-7 and 1.7 10-6 μM, respectively. Relative to most of the reported works on the determination of tinidazole, the developed method using carbon paste electrode which is an environmentally friendly, cheap, and simple working electrode exhibited linear dependence of peak current on concentration in the lower concentration region with relatively low LOD. Excellent recovery results with low % RSD for spiked standard tinidazole in tablet samples showed the potential applicability of the developed method for the determination of tinidazole in real samples. KEY WORDS: Carbon paste electrode, Differential pulse voltammetry, Tinidazole, Pharmaceutical tablets Bull. Chem. Soc. Ethiop. 2016, 30(1), 1-12.DOI: http://dx.doi.org/10.4314/bcse.v30i1.

    A Generalized Solution of Bianchi Type-V Models with Time-dependent GG and Λ\Lambda

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    We study the homogeneous but anisotropic Bianchi type-V cosmological model with time-dependent gravitational and cosmological "constants". Exact solutions of the Einstein field equations (EFEs) are presented in terms of adjustable parameters of quantum field theory in a spatially curved and expanding background. It has been found that the general solution of the average scale factor R as a function of time involved the hypergeometric function. Two cosmological models are obtained from the general solution of the hypergeometric function and the Emden-Fowler equation. The analysis of the models shows that for a particular choice of parameters in our first model, the cosmological "constant" decreases whereas the Newtonian gravitational "constant" increases with time, and for another choice of parameters, the opposite behaviour is observed. The models become isotropic at late times for all parameter choices of the first model. In the second model of the general solution, both the cosmological and gravitational "constants" decrease while the model becomes more anisotropic over time. The exact dynamical and kinematical quantities have been calculated analytically for each model.Comment: 21 pages, 12 figures. Published versio

    Guide to chicken health and management in Ethiopia: For farmers and development agents

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    Biotechnology and Biological Sciences Research Council, United KingdomDepartment for International Development, United Kingdo

    Constrained evolution of effective equation of state parameter in non-linear f(R,Lm)f(R, L_m) dark energy model: Insights from Bayesian analysis of cosmic chronometers and Pantheon samples

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    We conduct a Bayesian analysis of recent observational datasets, specifically the Cosmic Chronometers (CC) dataset and Pantheon samples, to investigate the evolution of the EoS parameter in dark energy models. Our study focused on the effective EoS parameter, which is described by the parametric form ωeff=11+m(1+z)n\omega_{eff}=-\frac{1}{1+m(1+z)^n}, where mm and nn are model parameters. This parametric form is applicable within the framework of f(R,Lm)f(R,L_m) gravity, where RR represents the Ricci scalar and LmL_m is the matter Lagrangian. Here, we examine a non-linear f(R,Lm)f(R,L_m) model characterized by the functional form f(R,Lm)=R2+Lmαf(R,L_m)=\frac{R}{2}+L_m^\alpha, where α\alpha is the free parameter of the model. We examine the evolution of several cosmological parameters, including the effective EoS parameter ωeff\omega_{eff}, the deceleration parameter qq, the density parameter ρ\rho, the pressure pp, and the statefinder parameters. Our analysis revealed that the constrained current value of the effective EoS parameter, ωeff0=0.68±0.06\omega_{eff}^{0}=-0.68\pm0.06 for both the CC and Pantheon datasets, points towards a quintessence phase. Moreover, at redshift z=0z=0, the deceleration parameter, q0=0.610.01+0.01q_0 = -0.61^{+0.01}_{-0.01}, indicates that the present Universe is undergoing accelerated expansion.Comment: The European Physical Journal Plus published versio

    Status of the ANAIS Dark Matter Project at the Canfranc Underground Laboratory

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    The ANAIS experiment aims at the confirmation of the DAMA/LIBRA signal. A detailed analysis of two NaI(Tl) crystals of 12.5 kg each grown by Alpha Spectra will be shown: effective threshold at 1 keVee is at reach thanks to outstanding light collection and robust PMT noise filtering protocols and the measured background is well understood down to 3 keVee, having quantified K, U and Th content and cosmogenic activation in the crystals. A new detector was installed in Canfranc in March 2015 together with the two previous modules and preliminary characterization results will be presented. Finally, the status and expected sensitivity of the full experiment with 112 kg will be reviewed.Comment: Contributed to the 11th Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, June 22 to 26, 201

    Background model of NaI(Tl) detectors for the ANAIS Dark Matter Project

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    A thorough understanding of the background sources is mandatory in any experiment searching for rare events. The ANAIS (Annual Modulation with NaI(Tl) Scintillators) experiment aims at the confirmation of the DAMA/LIBRA signal at the Canfranc Underground Laboratory (LSC). Two NaI(Tl) crystals of 12.5 kg each produced by Alpha Spectra have been taking data since December 2012. The complete background model of these detectors and more precisely in the region of interest will be described. Preliminary background analysis of a new 12.5 kg crystal received at Canfranc in March 2015 will be presented too. Finally, the power of anticoincidence rejection in the region of interest has been analyzed in a 4x 5 12.5 kg detector matrix.Comment: Contributed to the 11th Patras Workshop on Axions, WIMPs and WISPs, Zaragoza, June 22 to 26, 201

    Production and relevance of cosmogenic radionuclides in NaI(Tl) crystals

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    The cosmogenic production of long-lived radioactive isotopes in materials is an hazard for experiments demanding ultra-low background conditions. Although NaI(Tl) scintillators have been used in this context for a long time, very few activation data were available. We present results from two 12.5 kg NaI(Tl) detectors, developed within the ANAIS project and installed at the Canfranc Underground Laboratory. The prompt data taking starting made possible a reliable quantification of production of some I, Te and Na isotopes with half-lives larger than ten days. Initial activities underground were measured and then production rates at sea level were estimated following the history of detectors; a comparison of these rates with calculations using typical cosmic neutron flux at sea level and a selected description of excitation functions was also carried out. After including the contribution from the identified cosmogenic products in the detector background model, we found that the presence of 3H in the crystal bulk would help to fit much better our background model and experimental data. We have analyzed the cosmogenic production of 3H in NaI, and although precise quantification has not been attempted, we can conclude that it could imply a very relevant contribution to the total background below 15 keV in NaI detectors.Comment: Proceedings of the Low Radioactivity Techniques 2015 workshop, March 2015, Seattle (US
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