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An evolutionary computational framework for capacity-safety trade-off in an air transportation network

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Chinese Journal of Aeronautics 2019年第4期32卷 999-1010页

作者： md.Murad HOSSAIN Sameer alam Daniel DELAHAYE School of Engineering and Information Technology University of New South Wales School of Mechanical and Aerospace Engineering Nanyang Technological University MAIAA Laboratory Ecole Nationale de l'Aviation Civile

Airspace safety and airport capacity are two key challenges to sustain the growth in Air Transportation. In this paper, we model the Air Transportation Network as two sub-networks of airspace and airports, such that the safety and capacity of the overall Air Transportation network emerge from the interaction between the two. We propose a safety-capacity trade-off approach,using a computational framework, where the two networks can inter-act and the trade-off between capacity and safety in an Air Transport Network can be established. The framework comprise of an evolutionary computation based air traffic scenario generation using a flow capacity estimation module(for capacity), Collision risk estimation module(for safety) and an air traffic simulation module(for evaluation). The proposed methodology to evolve air traffic scenarios such that it minimizes collision risk for given capacity estimation was tested on two different air transport network topologies(random and small-world) with the same number of airports. Experimental results indicate that though airspace collision risk increases almost linearly with the increasing flow(flow intensity) in the corresponding airport network, the critical flow depend on the underlying network configuration. It was also found that, in general, the capacity upper bound depends not only on the connectivity among airports and their individual performances but also the configuration of waypoints and mid-air interactions among conflicts. Results also show that airport network can accommodate more traffic in terms of capacity but the corresponding airspace network cannot accommodate the resulting traffic flow due to the bounds on collision risk.

关键词： Airport network Airspace capacity Airspace safety Collision risk Flow intensity

Surface settlement induced by horizontal directional drilling

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Underground Space 2023年第1期8卷 94-108页

作者： Asif Ahmed md Azijul Islam md Zahangir alam Hashmi S.Quazi College of Engineering State University of New York Polytechnic Institute(SUNY Poly)UticaNY 13502USA Department of Civil Engineering The University of Texas at ArlingtonArlingtonTX 76019USA Department of Civil Engineering Bangladesh University of Engineering and Technology(BUET)Dhaka 1000Bangladesh Converse Consultants RedlandsCA 92373USA

Horizontal directional drilling(HDD)is a widely used trenchless method for underground utility *** associated ground settlement triggered by HDD depends on the size,types,and surface texture of pipe,diameter of borehole,and soil *** pre-sent study investigates the surface settlement due to the construction of a 1067 mm diameter HDD,which will replace an existing sewer siphon under the SR-60 highway in Chino,California using empirical,and numerical *** on the results obtained from the subsurface investigation,an empirical analysis was conducted *** by numerical modeling of the HDD using PLAXIS 2D soft-ware.A careful comparison between two different methods indicated closer values of surface settlement between the empirical method(7.3 mm)and the numerical modeling(4.6 mm).In addition,the shape of surface settlement and horizontal settlement curves for the empirical and numerical methods was found to be *** minor discrepancy between the two methods resulted as the numerical model can host several soil layers whereas the empirical equation can use only one type of ***,a parametric study was conducted to evaluate the effect of borehole cover depth,size,and soil parameters on surface *** was observed that soil strength param-eters yielded a greater effect on surface movement,whereas modulus of elasticity has a relatively smaller influence with zero contribution from Poisson’s ratio.

关键词： Horizontal directional drilling(HDD) Surface settlement Cover depth Soil arching Borehole

Implementation of Efficient B2G and V2G in Practical Cases

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Journal of Electronic Science and Technology 2018年第4期16卷 325-340页

作者： md Shahrukh Adnan Khan Kazi Mahtab Kadir md.Ibrahim Ibne alam md.Khairul alam Jianhui Wong Aseef Iqbal University of Asia Pacific Dhaka 1205 Bangladesh Department of Electrical and Electronic Engineering Universiti Tunku Abdul Rahman Kampar 31900Malaysia Chittagong Independent University Chittagong Bangladesh

In this paper, building to grid(B2G) and vehicle to grid(V2G) have been defined with clear and practical understanding. Both of them are new generation technologies which are the essential part of smart city living and crowd energy clustering. Firstly, an in-detailed overview has been provided with an introduction to B2G and V2G followed by a historical overview and theoretical analysis in respect to smart city planning. Next, a review is conducted on current and previous smart living research, which deals with B2G and V2G. Efficient B2G and V2G implementations in practical cases then have been discussed. Lastly, both of these technical prospects have been analyzed in crowd energy diagram.

关键词： Building to grid(B2G) crowd energy practical implementation smart city living vehicle to grid(V2G)

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

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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

Supersonic Moist Air Jet Impingements on Flat Surface

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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

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

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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

Influence of dielectric barrier discharge treatment on mechanical and dyeing properties of wool

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Plasma Science and Technology 2018年第6期20卷 89-98页

作者： Rahul NAVIK Sameera SHAFI md Miskatul alam md Amjad FAROOQ Lina LIN Yingjie CAI Hubei Provincial Engineering Laboratory for Clean Production and High Value Utilization of Bio-Based Textile Materials Wuhan Textile UniversityWuhan 430073People＇s Republic of China School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240People＇s Republic of China

Physical and chemical properties of wool surface significantly affect the absorbency,rate of dye bath exhaustion and fixation of the industrial ***,surface modification is a necessary operation prior to coloration process in wool wet processing *** treatment is an effective alternative for physiochemical modification of wool ***,optimum processing parameters to get the expected modification are still under investigation,hence this technology is still under development in the wool wet processing ***,in this paper,treatment parameters with the help of simple dielectric barrier discharge plasma reactor and air as a plasma gas,which could be a promising combination for treatment of wool substrate at industrial scale were schematically studied,and their influence on the water absorbency,mechanical,and dyeing properties of twill woven wool fabric samples are *** is expected that the results will assist to the wool coloration industries to improve the dyeing processes.

关键词： air plasma reactive dye surface energy wool

Financial management for custom hire service of tractor in Bangladesh

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International Journal of Agricultural and Biological Engineering 2013年第3期6卷 28-33页

作者： Anisur Rahman Most.Latifunnahar md Monjurul alam Department of Farm Power and Machinery Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

The main purpose of the study was to determine the economic parameters and effective schedules for tractor *** data from various sources were used in this *** essential data were collected from primary sources through *** costs were calculated and project financial profitability was determined by four major factors on farm financial measurement techniques,namely,benefit-cost ratio(BCR),net present value(NPV),internal rate of return(IRR),and payback *** the economic use,land topography and cropping pattern was developed to effective scheduling for tractor *** operating cost of tractor with implement was found to be US$9.25 per *** replacement of the existing tractor on expiry of economic life,the entrepreneur has to save an amount of US$219 per year in a bank *** on the operating cost,annual savings for replacement and a profit margin for the entrepreneur,the rent-out charge of the tractor is estimated at US$11.58 per *** 10%interest rate,the NPV of the tractor at existing condition is US$*** NPV of tractor indicates that tractor entrepreneurship is considered financially sound and the project is financially viable,with an average IRR of 36.96%.This is because IRR of the tractor was higher than the bank interest rate and it is highly profitable from the viewpoint of individual *** Payback period of tractor with implement was determined as 2.03 *** minimum tenure for an economic use of a common tractor used in agriculture is about 6310 *** this critical use,the utilization of a tractor is economical for a tractor *** on the cropping pattern two major and one minor turn-around periods are available in between cropping seasons for tilling *** time available for tilling of land is estimated about 140 days at 12 hours a day in a *** strengthen the existing capacity of the tractor customer hire service entrepreneurs an

关键词： tractor operating cost economic parameter effective scheduling tractor entrepreneur Bangladesh

A Computational Investigation on the Control of Cavity-Induced Pressure Oscillations Using Sub-Cavity

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Journal of Thermal Science 2006年第3期15卷 213-219页

作者： md.Mahbubul alam ShigeruMatsuo KenbuTeramoto ToshiakiSetoguchi Heuy-Dong Kim Department of Mechanical Engineering Chittagong University of Engineering and TechnologyChittagong 4349Bangladesh Department of Mechanical Engineering Saga University1Honjo-machiSaga shiSaga 840-8502Japan School of Mechanical Engineering College of Natural ScienceAndong National University388Song Cheon DongAndongKyung PookRepublic of Korea

A computational investigation has been conducted to determine the effectiveness of a passive control technique of attenuating cavity-induced pressure oscillations in a confined two-dimensional supersonic flow. The passive control technique is achieved by fitting two flat plates near the front wall of a square cavity at Mach number 1.83 at the cavity entrance. The results showed that the flat plates attached near the front wall of the cavity, discouraged the formation of feedback loop which is widely believed to be the reason of cavity resonance. The resultant amount of attenuation of pressure oscillations was also dependent on the length of the flat plate used as an oscillation suppressor.

关键词： compressible flow cavity-induced pressure oscillations passive control sub-cavity