329 research outputs found

    Catalytic decomposition of N2O over CeO2 supported Co3O4 catalysts

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    This work was aimed to design efficient catalysts for N2O decomposition at low temperatures. Cobalt oxide (Co3O4) was prepared by hydrothermal, precipitation and combustion methods and tested for N2O decomposition. It was found that the catalysts prepared by solution combustion synthesis were most active for this reaction. Subsequently, a series of ceria (CeO2) supported Co3O4 catalysts (xCeCo) were prepared by solution combustion method and used them for N2O decomposition. All the catalysts were characterized by analytical methods like XRD, TEM, BET, XPS, UV-Vis, Raman and H (2)-TPR. It was found that 10 and 20 wt..% loading of CeO2 on Co3O4 promoted the activity of Co3O4 towards N2O decomposition, whereas, higher loading of CeO2 reduced the activity. Typical results indicated that addition of CeO2 increases the surface area of Co3O4, and improves the reduction of Co3+ to Co2+ by facilitating the desorption of adsorbed oxygen species, which is the rate-determining step for the N2O decomposition over Co3O4 spinel catalysts. Optimal CeO2 loading can increase both dispersion and surface area of Co3O4 catalysts and weaken the Co-O bond strength to promote N2O decomposition

    Drug prescribing pattern in patients of myocardial infarction in a tertiary care teaching hospital of North India

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    Background: The term acute myocardial infarction (MI) should be used when there is evidence of myocardial necrosis in a clinical setting consistent with acute myocardial ischemia. Aims of this study were to assess drug prescribing pattern in patients of myocardial infarction and to compare prevalence of MI according to age, gender, diet, smoker or non-smoker, alcoholic or non-alcoholic, family history of cardiovascular disease.Methods: This observational study was conducted at department of pharmacology, in association with department of cardiology and included all patients of myocardial infarction visiting cardiology outpatient department or indoor patients and proforma was used to evaluate drug prescribing pattern.Results: Total 200 patients of acute myocardial infarction were analysed. Incidence of MI was more common in males (76%); age group 51-60 years (28.5%); non-vegetarians (68.5%); smokers (52.5%) and reduced physical activity (70.5%). 59.5% of patients had family history of cardiovascular disease. Commonly prescribed drugs were antiplatelets (100%) followed by hypolipidemic (99.5%), proton pump inhibitors (92%), antianginal (90.5%), anticoagulants (68.5%), thrombolytics (24.5%).Conclusions: This study provides insight towards drug prescribing pattern in MI patients. Most frequently prescribed drugs were antiplatelets followed by hypolipidemic and proton pump inhibitors. Patients had multiple risk factors and these can be reduced by lifestyle modifications

    Modified e-slotted patch antenna for WLAN/Wi-Max satellite applications

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    A low profile modified e-slotted microstrip antenna is proposed for multiple wireless communication applications. The performance of antenna is measured in terms of return loss, current distribution. The effect of variation of height of substrate on antenna impedance bandwidth is also studied. The antenna with overall size 30×50×.8m.m.3 resonates at eight frequencies which covers some important applications like GPS, wireless local area network (WLAN), worldwide interoperability for microwave access (WiMax), Satellite communication etc. The proposed antenna structure offers great advantages due to compact size, simple structure and multiple applications. The multi band antenna was designed and optimized using ansoft HFSS v13 simulator. The simulated result is good agreement with measured result

    The cosmological model in f(R,Tϕ) f(R,T^\phi) gravity with Scalar Field conformity

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    The homogeneous and isotropic cosmological model in generalized f(R,Tϕ) f(R,T^\phi) theories associated with scalar field is discussed, which is motivated by the f(R,T) f(R,T) theory of gravity studied by Harko et al. \cite{Harko:2011kv, Harko:2014pqa}. The f(R,Tϕ) f(R,T^\phi) gravity can be explained as f(R,T) f(R,T) gravity with a self-interacting scalar field ϕ \phi , where Tϕ T^\phi is the trace of the energy-momentum tensor. The parametrization of Hubble parameter H(t) H(t) is taken as αβeγt \alpha-\beta e^{-\gamma t} , where α \alpha , β\beta and γ\gamma are arbitrary constants such that α,γ>0 \alpha, \gamma>0 and β<0 \beta<0 . The model shows no space-time singularity and the expansion of the universe will continue forever, i.e., the future scenario of the universe attains Big Freeze. The model predicts the moderate inflationary scenario at the time of the evolution of the universe and it is consistent with Λ \Lambda CDM in late times. The consistency of the model has also been examined using recent observational Hubble dataset and supernovae dataset. Finally, the physical features of the model have been discussed in some detail.Comment: 12 pages, 13 figure

    Late time phantom characteristic of the model in f(R,T)f(R,T) gravity with quadratic curvature term

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    We propose a novel cosmological framework within the f(R,T)f(R,T) type modified gravity theory, incorporating a non-minimally coupled with the higher order of the Ricci scalar (RR) as well as the trace of the energy-momentum tensor (TT). Therefore, our well-motivated chosen f(R,T)f(R,T) expression is R+Rm+2λTn R + R^m + 2 \lambda T^n, where λ\lambda, mm, and nn are arbitrary constants. Taking a constant jerk parameter (jj), we derive expressions for the deceleration parameter (qq) and the Hubble parameter (HH) as functions of the redshift zz. We constrained our model with the recent Observational Hubble Dataset (OHD), PantheonPantheon, and Pantheon Pantheon + OHD datasets by using the analysis of Markov Chain Monte Carlo (MCMC). Our model shows early deceleration followed by late-time acceleration, with the transition occurring in the redshift range 1.10ztr1.151.10 \leq z_{tr} \leq 1.15. Our findings suggest that this higher-order model of f(R,T)f(R,T) gravity theory can efficiently provide a dark energy model for addressing the current scenario of cosmic acceleration.Comment: 14 pages, 12 figure

    A non-singular bouncing cosmology in f(R,T) f(R,T) gravity

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    We investigate a bounce realization in the framework of higher order curvature in f(R,T) f(R,T) modified theory of gravity. We perform a detailed analysis of the cosmological parameters to explain the contraction phase, the bounce phase, and the expansion phase. Furthermore, we observe a violation of the null energy condition, instability of the model, and a singularity upon deceleration at the bouncing point, which are the supporting results for a bouncing cosmology. The outcome of the slow roll parameters is satisfactory to understand the inflation era and the equation of state parameter exhibits a ghost condensate behavior of the model near the bounce. Additionally, we discuss the stability of the model using linear perturbations in the Hubble parameter as well as the energy density.Comment: 15 pages, 16 figure

    Role of serum interleukin-6 in deciding therapy for multidrug resistant oral lichen planus

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    Background: Oral lichen planus (OLP) is a T cell mediated immune response. T cells locally present in the involved tissues release cytokines like interleukin-6 (IL-6), which contributes to pathogenesis of OLP. Also IL-6 has been associated with multidrug resistance protein (MRP) expression by keratinocytes. Correspondingly, upregulation of MRP was found in OLP. We conducted this study to evaluate the effects of various drugs on serum IL-6 in OLP; and correlation of these effects with the nature of clinical response and resistance pattern seen in OLP lesions with various therapeutic modalities. Thus we evaluated the role of serum IL-6 in deciding therapy for multidrug resistant OLP. Material and Methods: Serum IL-6 was evaluated in 42 erosive OLP (EOLP) patients and 10 normal mucosa and 10 oral squamous cell carcinoma cases using ELISA technique. OLP patients were randomly divided into 3 groups of 14 patients each and were subjected to Pimecrolimus local application, oral Mycophenolate Mofetil (MMF) and Methotrexate (MTX) alongwith Pimecrolimus local application. IL-6 levels were evaluated before and after treatment. Results: Serum IL-6 levels were raised above 3pg/ml in 26.19% erosive OLP (EOLP) cases (mean- 3.72±8.14). EOLP (5%) cases with IL-6 levels above 5pg/ml were resistant in MTX group. However significant decrease in serum IL-6 corresponding with the clinical resolution was seen in MMF group. Conclusions: Significantly raised IL-6 levels in EOLP reflect the chronic inflammatory nature of the disease. As serum IL-6 levels significantly decreased in MMF group, correspondingly no resistance to treatment was noted. However with MTX there was no significant decrease in IL-6 and resistance to treatment was noted in some, especially plaque type lesions. Thus IL-6 can be a possible biomarker in deciding the best possible therapy for treatment resistant OLP
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