检索结果-南通市图书馆

Characterization of cytotoxicity of airborne particulates from urban areas of Lahore

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2012年第11期24卷 2028-2034页

作者： badar ghauri m.mansha Christian Khalil Institute of Space Technology Karachi 72500Pakistan School of Risk and Safety Sciences University of New South WalesAustralia

A number of species （organic and inorganic） in airborne particulates cause the toxicity to living being. The potential of in vitro test methods were explored for toxicity assessment of trace toxic elements （inorganic species） present in ambient air on human being （lungs）. A year long sampling of airborne particles （Pm2.5） was carded （April 2008 to march 2009） in Lahore, Pakistan. A total of thirty nine samples were collected on 47 mm Zefiuor Teflon filter membranes and each was analysed to characterize for the elements： Sb, As, Be, Cd, Cr, Co, Pb, mn, Hg using ICP-mS in water extract and total acid digestate. The samples cytotoxicity was also established using lung derived cells and mTS colorimetric assays. This generated dose response curves and IC50 values for the elemental mixtures identified on the Teflon filter membrane. The results indicated that even at low concentrations airborne elemental mixtures displayed an additive toxic effect.

关键词： particulate matter trace elements in vitro toxicity

Kinetic models of natural gas combustion in an internal combustion engine

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2010年第1期19卷 6-14页

作者： m. mansha A. R Saleemi badar m. ghauri Department of Chemical Engineering University of Engineering & Technology Lahore 54570 Pakistan SUPARCO HQs Karachi 49430 Pakistan

In this study, combustion of methane was simulated using four kinetic models of methane in CHEmKIN 4.1.1 for 0-D closed internal combustion （IC） engine reactor. Two detailed （GRImECH3.0 ＆ UBC mECH2.0） and two reduced （One step ＆ Four steps） models were examined for various IC engine designs. The detailed models （GRImECH3.0, ＆ UBC mECH2.0） and 4-step models successfully predicted the combustion while global model was unable to predict any combustion reaction. This study illustrated that the detailed model showed good concordances in the prediction of chamber pressure, temperature and major combustion species profiles. The detailed models also exhibited the capabilities to predict the pollutants formation in an IC engine while the reduced schemes showed failure in the prediction of pollutants emissions. Although, there are discrepancies among the profiles of four considered model, the detailed models （GRImECH3.0 ＆ UBC mECH2.0） produced the acceptable agreement in the species prediction and formation of pollutants.

关键词： kinetic models detailed models reduced models combustion methane IC engine

Prediction and measurement of pollutant emissions in CNG fired internal combustion engine

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2010年第5期19卷 539-547页

作者： m. mansha A. R. Saleemt Javed S. H badar m. ghauri Department of Chemical Engineering University of Engineering ＆ Technology Lahore 5457 Pakistan Institute of Space Technology Islamabad 44000 Pakistan

In the present study, the detailed reaction mechanisms were developed and Chemkin 4.1.1 was implemented to predict the formation of pollutant species in compressed natural gas （CNG） fired internal combustion （IC） engine. The proposed mechanisms were developed by coupling the EXGAS （an automatic mechanism generation tool for alkane oxidation） mechanisms with the Leed＇s NOz mechanism （version 2.0）. The simulation results of each proposed mechanism were validated by the experimental measurements for profiles of temperature, pressure and pollutant species （CO, NOx）. The rate of production analysis of each mechanism identified the important reactions in each mechanism which contributed to the formation of pollutant species. In spite of some discrepancies, the experimental measurements indicate that mechanism-IV （consisting of 208 reactions and 78 species） showed closer agreement for each of the predicted profiles of temperature, pressure and pollutant species （CO, NOx）.

关键词： kinetic mechanism rate of production oxidation pollutant species

Using Landsat images to monitor changes in the snow-covered area of selected glaciers in northern Pakistan

在线全文

学校读者我要写书评

暂无评论

Journal of mountain Science 2017年第10期14卷 2013-2027页

作者： Chaman GUL KANG Shi-chang badar ghauri mateeul HAQ Sher mUHAmmAD Shaukat ALI State Key Laboratory of Cryosphere Science Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 73000 China University of Chinese Academy of Sciences No.19A Yuquan Road Beijing 100049 China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101 China Institute of Space Technology (IST) Karachi Pakistan Space and Upper Atmosphere Research Commission (SUPARCO) Karachi Pakistan Global Change Impact Studies Centre (GCISC) Ministry of Climate Change Islamabad Pakistan

Landsat satellite images were used to map and monitor the snow-covered areas of four glaciers with different aspects(Passu: 36.473°N, 74.766°E;momhil: 36.394°N, 75.085°E; Trivor: 36.249°N,74.968°E; and Kunyang: 36.083°N, 75.288°E) in the upper Indus basin, northern Pakistan, from 1990-2014. The snow-covered areas of the selected glaciers were identified and classified using supervised and rule-based image analysis techniques in three different seasons. Accuracy assessment of the classified images indicated that the supervised classification technique performed slightly better than the rule-based technique. Snow-covered areas on the selected glaciers were generally reduced during the study period but at different rates. Glaciers reached maximum areal snow coverage in winter and premonsoon seasons and minimum areal snow coverage in monsoon seasons, with the lowest snow-covered area occurring in August and September. The snowcovered area on Passu glacier decreased by 24.50%,3.15% and 11.25% in the pre-monsoon, monsoon and post-monsoon seasons, respectively. Similarly, the other three glaciers showed notable decreases in snow-covered area during the pre-and post-monsoon seasons; however, no clear changes were observed during monsoon seasons. During pre-monsoon seasons, the eastward-facing glacier lost comparatively more snow-covered area than the westward-facing glacier. The average seasonal glacier surface temperature calculated from the Landsat thermal band showed negative correlations of-0.67,-0.89,-0.75 and-0.77 with the average seasonal snowcovered areas of the Passu, momhil, Trivor and Kunyang glaciers, respectively, during pre-monsoon seasons. Similarly, the air temperature collected from a nearby meteorological station showed an increasing trend, indicating that the snow-covered area reduction in the region was largely due to climate warming.

关键词： Snow-covered area Glacier Global warming Classification technique Northern Pakistan

Risk calculators and updated tools to select and plan a repeat biopsy for prostate cancer detection

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2015年第6期17卷 864-869,I0006页

作者： Igor Sorokin badar m mian Department of Urology Albany Medical College Albany NY USA.

millions of men each year are faced with a clinical suspicion of prostate cancer （PCa） but the prostate biopsy fails to detect the disease. For the urologists, how to select the appropriate candidate for repeat biopsy is a significant clinical dilemma. Traditional risk-stratification tools in this setting such as prostate-specific antigen （PSA） related markers and histopathology findings have met with limited correlation with cancer diagnosis or with significant disease. Thus, an individualized approach using predictive models such as an online risk calculator （RC） or updated biomarkers is more suitable in counseling men about their risk of harboring clinically significant prostate cancer, This review will focus on the available risk-stratification tools in the population of men with prior negative biopsies and persistent suspicion of PCa. The underlying methodology and platforms of the available tools are reviewed to better understand the development and validation of these models. The index patient is then assessed with different RCs to determine the range of heterogeneity among various RCs. This should allow the urologists to better incorporate these various risk-stratification tools into their clinical practice and improve patient counseling.

关键词： biomarkers prostate cancer repeat biopsy risk calculators

Current and emerging trends in prostate cancer immunotherapy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2019年第1期21卷 6-11页

作者： Adam Schatz badar m mian Division of Urology Albany Medical CollegeAlbany NY 12054USA.

There have been a number of recent developments in the treatment of castration-resistant prostate cancer which seek to exploit the hormonal ***,the castration-resistant prostate cancer remains a major challenge since this is the lethal and incurable phenotype which results in tens of thousands of deaths every *** has been emerging interest in utilizing anticancer immunotherapy in prostate cancer,especially since the development of *** other prostate cancer therapeutic vaccines including autologous and allogeneic vaccines,as well as viral vector-based vaccines,have demonstrated promising results in early trials.

关键词： prostate cancer immunotherapy hormonal axis

Detailed Kinetic mechanism of CNG Combustion in an IC Engine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Chemical Engineering and Science 2011年第3期1卷 102-117页

作者： muhammad mansha Javed Syed Hassan Anwar Rashid Saleemi badar m. ghauri Department of Chemical Engineering University of Engineering and Technology Lahore 5457 Pakistan

In this study, the four kinetic reaction mechanisms were developed to simulate the formation of pollutant species in CNG fired IC engine. The reactions were generated using EXGAS and coupled with Leed’s NOx reactions to develop four kinetic mechanisms. These reaction mechanisms described the combustion of natural gas at low (below 800 K) to high (above 1000 K) temperature in combustion chamber. The simulation studies predicted that the maximum cylinder pressure was achieved up to 18.0 atm & 40.0 atm under fuel leaner conditions (φ ≈0.6) and fuel rich conditions (φ=1.13 to 1.3) respectively. The simulation based data was compared with the experimental data (when engine was operated at 3000 rpm, φ=1.0, Pinlet=0.67 atm). For fuel rich conditions, high concentrations of CO were observed while NOx levels were lowered while the fuel leaner mixture produced the lower CO emissions and moderate levels of NOx emissions. The NOx and CO profiles depicted that mechanism-I, mechanism-II and mechanism III seemed to be inappropriate for predicting the emissions in due to CNG combustion IC engine. The molded data for mechanism-IV exhibited closer agreement with experimental measurements. The rate of production analysis identified the important reactions in each mechanism which were contributing in the formation of emission concentrations of pollutant species. Although each proposed mechanism illustrated some discrepancies among the profiles, mechanism-IV (consisting of 208 reactions and 78 species) showed good agreement with experimental data for pressure, temperature and pollutant species profiles.

关键词： Simulation EXGAS mechanism Oxidation Species Profile

Electrical features of radio-frequency atmospheric pressure helium discharge with and without dielectric electrodes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第2期21卷 60-67页

作者： H ASHRAF S Z A SHAH H I A QAZI m A KHAN S HUSSAIN m A badar S NIAZ m SHAFIQ Department of Physics University of Sargodha Department of Physics Quaid-i-Azam University

A comparative study of radio-frequency atmospheric pressure glow discharge(rf APGD)generated in helium with and without dielectric electrodes to investigate the effect of electrodes insulation on electrical features of APGD is presented. In the α mode, both the rf APGDs remain volumetric, stable and uniform. In the γ mode, the APGD without dielectric electrodes shrinks into a constricted plasma column whereas APGD with dielectric electrodes remains stable and retains the same volume without plasma constriction even at higher densities of discharge current. A comparison of electrical features of both rf APGDs in normal and abnormal glow discharge regimes is presented. In both APGDs with and without dielectric electrodes,impedance measurements have been performed and compared with equivalent circuit *** measured impedance data is found to be in good agreement with simulated data.

关键词： radiofrequency atmospheric pressure glow discharge dielectric electrodes plasma stability control

Spectroscopic Study of a Radio-Frequency Atmospheric Pressure Dielectric Barrier Discharge with Anodic Alumina as the Dielectric

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2013年第9期15卷 900-903页

作者： H.I.A.QAZI m.SHARIF S.HUSSAIN m.A.badar H.AFZAL Department of Physics University of SargodhaSargodha 40100Pakistan Department of Physics GC UniversityFaisalabad 38000Pakistan

This paper presents the fabrication and a spectroscopic study of a stable radio- frequency dielectric barrier discharge （RF DBD） in Ar with a novel dielectric, anodic alumina, at atmospheric pressure. Dielectric electrodes are fabricated from commercially available low cost impure aluminum strips by a two-step anodization process in 0.3 m solution of oxalic acid. The discharge is found to be stable with excellent spatial uniformity for the RF input power range of 30～80 W. Excitation and rotational temperatures measured in the experiment range of 1472～3255 K and 434～484 K, respectively, as the input power changes from 30 W to 80 W. These temperature ranges are suitable for surface modification applications.

关键词： radio frequency atmospheric pressure glow discharge dielectric barrier dis-charge anodic alumina dielectric