检索结果-南通市图书馆

Kinetics of Acid Blue 1 Adsorption from Aqueous Solution by Carbonaceous Substrate Produced from Biotic Precursor

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2007年第5期25卷 596-604页

作者： FAZLULLAH, Khan Bangash SULTAN, alam IRSHAD, Ahmad Institute of Chemical Sciences University of Peshawar Peshawar 25120 Pakistan National Center of Excellence in Geology University of Peshawar Peshawar 25120 Pakistan

Adsorption of acid blue 1 from aqueous solution onto carbonaceous substrate produced from the wood of Paulownia tomentosa was investigated. The samples characterized by FTIR, SEM, EDS and XRD techniques, indicated that the surface functional groups like carboxyl, lactones or phenols and ethers have disappeared at high activation temperature （800 ℃） and as a result porous structure was developed that has a positive effect on the adsorption capacity. Bangham and parabolic diffusion models were applied to the kinetic adsorption data, which show that the adsorption of acid blue 1 was a diffusion controlled process. The reaction rate increased with the increase in temperatures of both the adsorption and activation. Thermodynamic parameters like △E^≠, △H^≠, △S^≠ and △G^≠ were calculated from the kinetic data. The negative values of △S^≠ reflected the decrease in the disorder of the system at the solid-solution interface during adsorption. Gibbs free energy （△G^≠）, representing the driving force for the affinity of dye for the carbon surface, increased with the increase in sample activation and the adsorption temperatures.

关键词： activated carbon chemical treatment thermal activation adsorption functional group XRD SEM EDS FTIR

Solvent-free preparation of arylaminotetrazole derivatives using aluminum(Ⅲ) hydrogensulfate as an effective catalyst

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

Chinese Chemical Letters 2010年第8期21卷 892-896页

作者： Ferydoon Khamooshi Ali Reza Modarresi-alam Deparment of Chemistry Faculty of ScienceUniversity of Sistan and Baluchestan

An efficient and simple method for the preparation of 5-arylamino-1H-tetrazole and 1-aryl-5-amino-1H-tetrazole derivatives is reported using aluminum（Ⅲ） hydrogensulfate（Al（HSO4）3） as an effective heterogeneous catalyst from secondary arylcyanamides. Generally,when the substitution in arylcyanamide is strongly electron-withdrawing the position of equilibrium would shift toward the isomer of 1-aryl-5-amino-1H-tetrazole（B） and as the electron-donating of substituent increased,the position of equilibrium is shifted toward the isomer of 5-arylamino-1H-tetrazole（A）.The present methodology offers several advantages,such as excellent yields,short reaction times,easy work-up and greener conditions.

关键词： 5-Arylamino-1H-tetrazole 1-Aryl-5-amino-1H-tetrazole Secondary arylcyanamide Aluminum(Ⅲ) hydrogensulfate(Al(HSO_4)_3) Heterogeneous catalyst Solvent-free Solid acid

Control Algorithm Based on Limit Cycle Oscillator-FLL for UPQC-S with Optimized PI Gains

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2020年第3期6卷 649-661页

作者： Sabha Raj Arya Sayed Javed alam Papia Ray Department of Electrical Engineering Sardar Vallabhai National Institute of TechnologySuart-395007(Gujarat)gIndia Department of Electrical Engineering Veer Surendra Sai University of Technology(Government University)BurlaSambalpurIndia

This paper involves a limit cycle oscillator-frequency lock loop(LCO-FLL)based control algorithm for unified power quality controllers-S type(UPQC-S)for compensation of reactive power,to maintain a unity power factor,regulate constant voltage at the PCC,mitigate sag,swell and to eliminate *** this approach,an extraction of fundamental in-phase and quadrature components for the estimation of reference signals are taken from the LCO-FLL *** control LCO-FLL provides a high grade of protection against sag-swell voltages,unbalance loading and harmonics present in the utility *** addition to that,it has advantageous characteristics of synchronization with the grid frequency at any previously mentioned conditions without use of phase locked loops or trigonometric *** advantages of the LCO-FLL are to give useful information to estimate fundamental components from a highly polluted grid *** values obtained from the JAYA optimization algorithm are used to fine-tune the proportional integral(PI)controller gains,so that it maintains DC link voltage to the desired *** mean square error(MSE)is employed as an objective function for optimizing the error between actual and reference *** control algorithm based on LCO-FLL is developed in MATLAB/Simulink software and it is tested for power conditioning features.

关键词： JAYA MSE LCO-FLL PI Tuning Sag unbalanced VSC

A Spatial-Temporal Network Perspective for the Propagation Dynamics of Air Traffic Delays

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

Engineering 2021年第4期7卷 452-464页

作者： Qing Cai Sameer alam Vu N.Duong School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

Intractable delays occur in air traffic due to the imbalance between ever-increasing air traffic demand and limited airspace *** air traffic is associated with complex air transport systems,delays can be magnified and propagated throughout these systems,resulting in the emergent behavior known as delay *** understanding of delay propagation dynamics is pertinent to modern air traffic *** this work,we present a complex network perspective of delay propagation ***,we model air traffic scenarios using spatial–temporal networks with airports as the *** establish the dynamic edges between the nodes,we develop a delay propagation method and apply it to a given set of air traffic *** on the constructed spatial-temporal networks,we suggest three metrics-magnitude,severity,and speed-to gauge delay propagation *** validate the effectiveness of the proposed method,we carry out case studies on domestic flights in the Southeastern Asia region(SAR)and the United *** demonstrate that the propagation magnitude in terms of the number of flights affected by delay propagation and the amount of propagated delays for the US traffic are respectively five and ten times those of the *** further reveal that the propagation speed for US traffic is eight times faster than that of the *** delay propagation dynamics reveal that about six hub airports in the SAR have significant propagated delays,while the situation in the United States is considerably worse,with a corresponding number of around *** work provides a potent tool for tracing the evolution of air traffic delays.

关键词： Air traffic Transport systems Delay propagation dynamics Spatial–temporal networks

Optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum, using response surface methodology

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2007年第1期19卷 23-28页

作者： Sarkar Mannan Ahmadun Fakhru'l-Razi Md Zahangir alam Department of Chemical and Environmental Engineering Faculty of Engineering University Putra Malaysia (UPM)43400 UPM SerdangSelangorD.E.Malaysia. Department of Biotechnology Engineering Faculty of Engineering International Islamic University Malaysia (IIUM)Jalan Gombak53100 Kuala LumpurMalaysia.

The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology （RSM）. The three parameters namely temperature of 33℃, agitation of 150 r/min, and pH of 5 were chosen as center point from the previous study of fungal treatment. The experimental data on chemical oxygen demand （COD） removal （%） were fitted into a quadratic polynomial model using multiple regression analysis. The optimum process conditions were determined by analyzing response surface three-dimensional surface plot and contour plot and by solving the regression model equation with Design Expert software. Box-Behnken design technique under RSM was used to optimize their interactions, which showed that an incubation temperature of 32.5℃, agitation of 105 r/min, and pH of 5.5 were the best conditions. Under these conditions, the maximum predicted yield of COD removal was 98.43%. These optimum conditions were used to evaluate the trail experiment, and the maximum yield of COD removal was recorded as 98.5%.

关键词： optimization response surface methodology Penicillium activated sludge domestic wastewater sludge

Supersonic Moist Air Jet Impingements on Flat Surface

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第1期19卷 51-59页

作者： alam Miah Md.Ashraful MATSUO Shigeru SETOGUCHI Toshiaki Graduate School of Science & Engineering Saga University1Honjo-machiSaga-shiSaga 840-8502Japan Department of Mechanical Engineering Saga University1Honjo-machiSaga-shiSaga 840-8502Japan Institute of Ocean Energy Saga University1Honjo-machiSaga-shiSaga 840-8502Japan

Pronounced aeroacoustic resonances are exhibited in the flow field where a jet emerges from an orifice or a nozzle and impinges on a solid surface. One instance where such resonances are produced is in a high speed jet impingement, such as in the space launch vehicle systems, jet-engine exhaust impingement, and in the short take-off and vertical landing （STOVE） aircraft, etc. A highly unsteady flowfield leading to a drastic increase of noise level with very high dynamic pressure and thermal loads are noticed on nearby surfaces results dramatic lift loss, severe ground erosion and hot gas ingestion to the inlet in the jet engines. This highly unsteady behavior of the im- pinging jets is due to a feedback loop between the fluid and acoustic fields. In actual jet flow, the working gas may contain condensable gas such as steam or moist air. In these cases, the non-equilibrium condensation may occur at the region between nozzle exit and an object. The jet flow with non-equilibrium condensation may be quite different from that without condensation. Therefore, in this study, the effect of the non-equilibrium condensation of moist air on the axisymmetric under-expanded supersonic impinging jet on a vertical flat plate was investigated numerically.

关键词： compressible flow supersonic impinging non-equilibrium condensation oscillation

Dispersion and attenuation of torsional wave in a viscoelastic layer bonded between a layer and a half-space of dry sandy media

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第9期38卷 1313-1328页

作者： P.alam S.KUNDU S.GUPTA Department of Applied Mathematics Indian Institute of Technology(Indian School of Mines)Dhanbad 826004JhrkhandIndia

Propagation of a torsional wave in a doubly-layered half-space structure of an initially stressed heterogeneous viscoelastic layer sandwiched between a layer and a half-space of heterogeneous dry sandy media is studied. A closed form complex expression for the velocity profile is obtained under effective boundary conditions. The real part of the complex expression provides a dispersion equation, and the imaginary part yields a damping equation. The derived dispersion and damped equations are in well agreement with the classical Love wave condition. In addition, to study the effect of the dissipation factor, the attenuation coefficient, the sandy parameters, the initial stress, the hetero- geneity parameters, and the thickness ratio parameter, some noteworthy contemplations are made by numerical calculations and graphical visuals. The results of this paper may present a deeper insight into the behaviour of propagation phenomena in heterogeneous viscoelastic and heterogeneous dry sandy materials that can provide a theoretical guide for the design and optimization in the field of earthquake engineering. The study also reveals that the presence of a damping part due to viscoelasticity affects the torsional wave propagation significantly.

关键词： attenuation dissipation viscoelastic sandy heterogeneous initial stress,phase damping

Motor neuroprosthesis for injured spinal cord:who is an ideal candidate?

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2017年第11期12卷 1809-1810页

作者： Monzurul alam Yong-ping Zheng Department of Biomedical Engineering The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina

A spinal cord injury （SCI） shatters people＇s lives in a fraction of a second, leaving them paralyzed, often for the rest of their lives. The devastation caused by SCI is significant around the world. Though the exact prevalence of the injury is un- known, according to recent statistics, the number of injuries is estimated to be between 1.65 and 7.06 million worldwide （alam and He, 2014）. A recent report from the World Health Organization （WHO） states that, every year, 250,000-500,000 new spinal cord injuries occur around the world （Bickenbach et al., 2013）. Beyond the physical sufferings of these paralyzed individuals, SCI has huge economic and social impacts. In the United States alone,

关键词： Motor neuroprosthesis ideal candidate

The Effect of Non-Equilibrium Condensation on Supersonic Air Flows over Rectangular Cavities

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2007年第1期16卷 33-39页

作者： Miah MD. Ashraful alam Md. Mahbubul alam Shigeru MATSUO Kenbu TERAMOTO Toshiaki SETOGUCHI Heuy Dong KIM Shen YU Department of Mechanical Engineering Khulna University of Engineering ＆ Technology Khulna-9203 Bangladesh Department of Mechanical Engineering Saga University 1 Honjo-machi Saga-shi Saga 840-8502 Japan School of Mechanical Engineering College of Natural Science Andong National University 388 Song Cheon Dong Andong Kyung Pook Republic of Korea Institute of Engineering Thermophysics Chinese Academy of Sciences EO. Box 2706 Beijing 100080 China

Numerical simulations have been carded out for a supersonic two-dimensional flow over open, rectangular cavities （length-to-depth ratios are L/D = 1.0 and 3.0） in order to investigate the effect of non-equilibrium condensation of moist air on supersonic internal flows around the cavity for the flow Mach number 1.83 at the cavity entrance. In the present computational investigation, a condensing flow was produced by an expansion of moist air in a Laval nozzle. The computational results showed that the upstream traveling compression waves become weaker than those without the condensation. Consequently, the weaker compression waves cannot excite the shear layer strongly and amplitudes of oscillation in the cavity became smaller than those without the condensation. The occurrence of the non-equilibrium condensation in case of L/D = 1.0 affected strongly the amplitude and frequency of oscillation in the cavity compared with L/D = 3.0.

关键词： compressible flow supersonic cavity oscillation non-equilibrium condensation numerical simulation