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Screening of solanum surrattense for antibacterial,antifungal,phytotoxic and haemagglutination

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Journal of Traditional Chinese Medicine 2012年第4期32卷 616-620页

作者： Haroon ahmad Nasar Ali Bashir ahmad Ibrar Khan Centre of Biotechnology and Microbiology University of Peshawar 25000Pakistan

OBJECTIVE： Plants produce a variety of useful bio- active materials that have been used to cure differ- ent ailments of human beings. With the same idea in mind, the crude methanolic extract and various fractions of Solanum surrattense were screened for antibacterial, antifungal, phytotoxic and heamag- glutination activities. METHODS： Standardized assays were followed for the determination of antibacterial, antifungal phy- totoxic and heamagglutination activity. RESULTS： The results of the antibacterial showed that crude methanolic extract was significantly ac- tive against Staphylococcus aureus （86%） The n- hexane fraction showed good activity against Pseu- domonas aerogenosa （66.6%） and Bacillus subtilus （66.6%）. The crude methanolic extract and various fractions were inactive against all test fungi. The crude methanolic extract, n-hexane, CHCI3 and aqueous fractions showed moderate phytotoxic ac- tivities of 46.67%, 40.00%, 33.34% and 33.34% re- spectively at 1000 pg/mL. The crude methanolic ex- tract and various fractions S. surrattense were un- able to aqqlutinate RBCs of the human blood indi-cating that this species lack phytolectins. CONCLUSION： The test sample showed significant antibacterial activity, no antifungal and heamagglu- tination activity while moderate phytotoxic was ob- served against Lemna minor L.

关键词： Solanum surrattense Anti-bacterialagents Antifungal agents Phytotoxic Haemagglu-tination

Free Vibration Analysis of Symmetrically Laminated Composite Plates on Elastic Foundation and Coupled with Stationary Fluid

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China Ocean Engineering 2018年第3期32卷 266-277页

作者： Arash SHAHBAZTABAR ahmad RAHBAR-RANJI Department of Ocean Engineering AmirK abir University of Technology

Free vibration analysis of symmetrically laminated composite plates resting on Pasternak elastic support and coupled with an ideal, incompressible and inviscid fluid is the objective of the present work. The fluid domain is considered to be infinite in the length direction but bounded in the depth and width directions. In order to derive the eigenvalue equation, Rayleigh-Ritz method is applied for the fluid-plate-foundation system. The efficiency of the method is proved by comparison studies with those reported in the open literature. At the end, parametric studies are carried out to examine the impact of different parameters on the natural frequencies.

关键词： free vibration analysis laminated composite plate fluid-plate-foundation interaction Rayleigh-Ritz method Pasternak foundation

Semiquantitative determination of some nitrogen compounds by the formation of charge-transfer complexes of diphenylamine with p-dimethylaminobenzaldehyde by capillary solid-state spot-tests

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Chinese Chemical Letters 2010年第6期21卷 720-724页

作者： Ishaat M.Khan ahmad Naeem Afaq ahmad Department of Chemistry Faculty of Science Aligarh Muslim UniversityAligarh 202002UPIndia Department of chemistry Shibli National CollegeAzamgarh 276002UPIndia

The interactions of p-dimethylaminobenzaldehyde(p-DAB) and potassium hydrogen sulphate(PHS) in equimolar ratio with various concentration of diphenylamine(solid test material) have been investigated by capillary spot-tests technique in order to investigate the effect of temperature and volume of material in *** formation of the colored boundary in the capillary is taken for the detection of organic compounds by spot-tests at different temperature and volume of solid test material.

关键词： p-DAB Capillary spot-tests Solid material Potassium hydrogen sulphate

A step forward towards a comprehensive framework for assessing liquefaction land damage vulnerability:Exploration from historical data

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Frontiers of Structural and Civil Engineering 2020年第6期14卷 1476-1491页

作者： Mahmood ahmad Xiao-Wei TANG Jiang-Nan QIU Feezan ahmad Wen-Jing GU State Key Laboratory of Coastal and Ofishore Engineering Dalian University of TechnologyDalian 116024China Department of Civil Engineering University of Engineering and Technology Peshawar(Bannu Campus)Bannu 28100Pakistan School of Economics&Management Dalian University of TechnologyDalian 116024China Deparment of Civil Enginering Abasyn UniversitPeshawar 25000Pakistan

The unprecedented liquefaction-related land damage during earthquakes has highlighted the need to develop a model that better interprets the liquefaction land damage vulnerability(LLDV)when determining whether liquefaction is likely to cause damage at the ground's *** paper presents the development of a novel comprehensive framework based on select case history records of cone penetration tests using a Bayesian belief network(BBN)methodology to assess seismic soil liquefaction and liquefaction land damage potentials in one *** BBN-based LLDV model is developed by integrating multi-related factors of seismic soil liquefaction and its induced hazards using a machine learming(ML)algorithm-K2 and domain knowledge(DK)data fusion *** with the C4.5 decision tree-J48 model,naive Bayesian(NB)classifier,and BBN-K2 ML prediction methods in terms of overall accuracy and the Cohen's kappa coefficient,the proposed BBN K2 and DK model has a better performance and provides a substitutive novel LLDV framework for characterizing the vulnerability of land to liquefaction-induced *** proposed model not only predicts quantitatively the seismic soil liquefaction potential and its ground damage potential probability but can also identify the main reasons and fault-finding state combinations,and the results are likely to assist in decisions on seismic risk mitigation measures for sustainable *** proposed model is simple to perform in practice and provides a step toward a more sophisticated liquefaction risk assessment *** study also interprets the BBN model sensitivity analysis and most probable explanation of seismic soil liquefed sites based on an engineering point of view.

关键词： Bayesian belief network liquefaction-induced damage potential cone penetration test soil liquefaction structural leaming and domain knowledge

Comprehensive performance analysis and optimization of 1,3-dimethylimidazolylium dimethylphosphate-water binary mixture for a single effect absorption refrigeration system

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Frontiers in Energy 2022年第3期16卷 521-535页

作者： Gorakshnath Takalkar ahmad K.Sleiti Collage of Engineering Qatar UniversityDoha2713Qatar

The energy and exergy analyses of the absorption refrigeration system (ARS) using H2O-[mmim][DMP] mixture were investigated for a wide range of temperature. The equilibrium Dühring (P-T-XIL) and enthalpy (h-T-XIL) of mixture were assessed using the excess Gibbs free non-random two liquid (NRTL) model for a temperature range ??? of 20°C to 140°C and XIL from 0.1 to 0.9. The performance validation of the ARS cycle showed a better coefficient of performance (COP) of 0.834 for H2O-[mmim][DMP] in comparison to NH3-H2O, H2O-LiBr, H2O-[emim][DMP], and H2O-[emim][BF4]. Further, ARS performances with various operating temperatures of the absorber (Ta), condenser (Tc), generator (Tg), and evaporator (Te) were simulated and optimized for a maximum COP and exergetic COP (ECOP). The effects of Tg from 50°C to 150°C and Ta and Tc from 30°C to 50°C on COP and ECOP, the Xa, Xg, and circulation ratio (CR) of the ARS were evaluated and optimized for Te from 5°C to 15°C. The optimization revealed that Tg needed to achieve a maximum COP which was more than that for a maximum ECOP. Therefore, this investigation provides criteria to select low grade heat source temperature. Most of the series flow of the cases of cooling water from the condenser to the absorber was found to be better than the absorber to the condenser.

关键词： ionic liquid driven absorption cycle H2O-[mmim][DMP] coefficient of performance(COP) exergy analysis thermodynamics mixture property

Permutation Encoding for Pilot Coordination in Multi-user Massive MIMO

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第S1期35卷 59-62页

作者： Hafiz ahmad Khalid College of Electronics Science and Technology Beijing University of Posts and Telecommunications

Pilot plays an essential role in a duplex communication *** methods have been proposed for pilot assignment over specific *** the help of permutation encoding,we implemented a genetic algorithm for optimizing pilot assignment in a multi-user massive multiple input multiple output(MIMO)*** show improvement on existing results especially in the case of strong user estimation rates.

关键词： genetic algorithms performance analysis permutation encoding

Multi-period Power System State Estimation with PMUs Under GPS Spoofing Attacks

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Journal of Modern Power Systems and Clean Energy 2020年第4期8卷 597-606页

作者： Paresh Risbud Nikolaos Gatsis ahmad Taha Department of Electrical and Computer Engineering University of Texas at San AntonioSan AntonioUSA IEEE

This paper introduces a dynamic network model together with a phasor measurement unit(PMU)measurement model suitable for power system state estimation under spoofing attacks on the global positioning system(GPS)receivers of *** spoofing attacks may introduce time-varying phase offsets in the affected PMU *** algorithm is developed to jointly estimate the state of the network,which amounts to the nodal voltages in rectangular coordinates,as well as the time-varying *** algorithm features closedform *** effectiveness of the algorithm is verified on the standard IEEE transmission *** is numerically shown that the estimation performance is improved when the dynamic network model is accounted for compared with a previously reported static approach.

关键词： Dynamic state equation global positioning system(GPS)spoofing phasor measurement unit(PMU) state estimation time synchronization weighted least squares

Numerical investigation for the suitable choice of bubble diameter correlation for EMMS/bubbling drag model

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Chinese Journal of Chemical Engineering 2022年第7期35卷 254-270页

作者： Nouman ahmad Jianqiang Deng Muhammad Adnan Shaanxi Key Laboratory of Energy Chemical Process Intensification Xi’an 710049China School of Chemical Engineering and Technology Xi’an Jiaotong UniversityXi’an 710049China

Mesoscale bubbles exist inherently in bubbling fluidized beds and hence should be considered in the constitutive modeling of the drag *** energy minimization multiscale bubbling(EMMS/bubbling)drag model takes the effects of mesoscale structures(i.e.,bubbles)into the modeling of drag coefficient and thus improves the coarse-grid simulation of bubbling and turbulent fluidized ***,its dependence on the bubble diameter correlation has not been thoroughly *** hydrodynamic disparity between homogeneous and heterogeneous fluidization is accounted for by the heterogeneity index,H_(d),which can be affected by choice of bubble diameter *** this choice of bubble diameter correlation influences the model prediction calls for further fundamental *** article incorporated seven different bubble diameter correlations into EMMS/bubbling drag model and studied their effects on H_(d).The performance of these correlations has been compared with the correlation used previously by EMMS/bubbling drag *** found that some of the correlations predicted lower Hd by order of a magnitude than the correlation used by the original EMMS/bubbling *** on such analysis,we proposed a modification in the EMMS drag model for bubbling and turbulent fluidized beds.A computational fluid dynamics(CFD)simulation using two-fluid model with the modified EMMS/bubbling drag model was performed for two bubbling and one turbulent fluidized *** distribution,time averaged solid concentration and axial solid concentration profiles were studied and compared with the previous version of the EMMS/bubbling drag model and experimental *** found that the right choice of bubble diameter correlations can significantly improve the results for CFD simulations.

关键词： Mesoscale Bubbles Energy minimization multiscale(EMMS) Heterogeneity index Bubbling fluidized bed

Optimizing calcination of coal by-products for maximizing REE leaching recovery and minimizing Al,Ca,and Fe contamination

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Journal of Rare Earths 2024年第7期42卷 1354-1365,I0006页

作者： Tushar Gupta ahmad Nawab Rick Honaker MP Materials Mountain Pass Mine 67750 Bailey RoadMountain PassCA92366USA Department of Mining Engineering University of KentuckyLexingtonKY40506USA

High-temperature calcination is effective in improving the leaching characteristics of rare earth elements(REEs)from conventional REE-bearing minerals by transforming them into more leachable ***,the recovery of contaminants such as Al,Fe,and Ca also increases *** objective of the study was to maximize the REE extraction while minimizing the concentration of contaminant ions(Al,Ca,and Fe)in the leach *** density fractions of the coarse refuse from the Baker and Fire Clay seam coal refuse were pulverized to a top size of 180μm and used as a feedstock for the *** the samples generated from thermal treatment were leached at 1%(w/v)using 1.2 mol/L sulfuric acid at 75℃ for 2 *** results from a parametric program based on a Box-Behnken design were used for modeling and optimization of three operating parameters associated with the lab-scale calcination *** parameters included temperature(400-800℃),ramp rate(2-10℃/min)and holding time(0-120 min).It was determined that the calcination temperature was the most significant parameter influencing REE *** majority of the heavy rare earth elements(HREEs)were found to be present in an insoluble form in the calcination products and were marginally affected by thermal treatment.A strong correlation between light rare earth elements recovery(LREEs)and Al suggested a possible association with *** optimum operating conditions for high REE recovery with comparatively lower contaminant concentration for 1.6 specific gravity float and 2.2 sink fractions of Baker and Fire Clay seam material were determined to be at 776,800℃ and 407,800℃,calcining temperatures,respectively.A higher optimum temperature of 1.6 float fraction of Baker seam relative to Fire Clay seam material was due to elevated pyrite concentration in Baker seam *** treatment at 400℃ converted pyrite into a soluble intermedium iron oxide,resulting in a high Fe content in the ***

关键词： Calcination Optimization Rare earth elements Coal refuse