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Proton conductivity performance and its correlation with physiochemical properties of proton exchange membrane(PEM)

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Chinese Journal of Chemical Engineering 2024年第10期74卷 100-116页

作者： Mirza Nusrat Sweety md.abdus Salam Hydrogen Energy Laboratory Bangladesh Council of Scientific and Industrial Research(BCSIR)Chattogram 4220Bangladesh Institute of Mining Mineralogy and Metallurgy(IMMM)BCSIRJoypurhat 5900Bangladesh BCSIR Dhaka Laboratories Dhaka 1205Bangladesh

Graphene oxide(GO)filler containing diversified Nafion-based proton exchange membrane(PEM)is studied to know the unique physical and chemical properties and performances of ***-SPEEK 1%-GO 0.75%(NSG-0.75%)composite shows the highest proton conductivity of 0.327 S·cm^(-1) at 90℃ and 100%RH(relative humidity)among all the PEM *** descending order of significant proton conductivity is found as;Nafion-sPGO(1%)0.306 S·cm^(-1)>Nafion/ZIF-8@GO 0.280 S·cm^(-1)>Nafion/PGO(2%)0.277 S·cm^(-1)>Nafion/GO-sulfur(3%)0.232 S·cm^(-1)>Nafion/GO-poly-SPM-co-PEGMEMA(1%)0.229 S·cm^(-1)>Nafion/Ce-sPGO(1%)0.215 S·cm^(-1).The proton conductivity,water uptake capacity and ion exchange capacity,hydration number,thermal and oxidative stability,mechanical integrity(tensile strength),maximum power,and current density are found to be increased while activation energy and fuel crossover show a decrement as GO or modified GO is incorporated in the Nafion *** component analysis(PCA)predicted a significant correlation between the proton conductivity and the properties;the water uptake capacity,ion exchange capacity,hydration number,maximum power density,and maximum current density are 0.598%,0.688%,0.894%,0.980%,and 0.852%accordingly.A multiple linear model equation of proton conductivity is defined with the parameters of water uptake capacity,ion exchange capacity,hydration number,maximum power density,and maximum current density whereas the regression coefficient is 0.9923.

关键词： Fuel cells Membranes Nafion GO-filler Proton conductivity Principal component analysis

Analysis and Modeling of Propagation in Tunnel at 3.7 and 28 GHz

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Computers, Materials & Continua 2022年第5期71卷 3127-3143页

作者： md.abdus Samad Dong-You Choi Department of Information and Communication Engineering Chosun UniversityGwangju61452Korea Department of Electronics and Telecommunication Engineering International Islamic University ChittagongChittagong4318Bangladesh

In present-day society,train tunnels are extensively used as a means of ***,to ensure safety,streamlined train operations,and uninterrupted internet access inside train tunnels,reliable wave propagation modeling is *** have experimented and measured wave propagation models in a 1674 m long straight train tunnel in South *** measured path loss and the received signal strength were modeled with the Close-In(CI),Floating intercept(FI),CI model with a frequency-weighted path loss exponent(CIF),and alpha-beta-gamma(ABG)models,where the model parameters were determined using minimum mean square error(MMSE)*** measured and the CI,FI,CIF,and ABG modelderived path loss was plotted in graphs,and the model closest to the measured path loss was identified through *** on the measured results,it was observed that every model had a comparatively lower(n<2)path loss exponent(PLE)inside the *** also determined the path loss component’s possible deviation(shadow factor)through a Gaussian distribution considering zero mean and standard deviation calculations of random error *** FI model outperformed all the examined models as it yielded a path loss closer to the measured datasets,as well as a minimum standard deviation of the shadow factor.

关键词： Path loss shadow factor telecommunications train tunnel wave propagation wireless networks

Describing Fuzzy Membership Function and Detecting the Outlier by Using Five Number Summary of Data

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American Journal of Computational Mathematics 2020年第3期10卷 410-424页

作者： md. Farooq Hasan md. abdus Sobhan Department of Mathematics and Statistics Bangladesh University of Business and Technology Dhaka Bangladesh

One of the most important activities in data science is defining a membership function in fuzzy system. Although there are few ways to describe membership function like artificial neural networks, genetic algorithms etc.;they are very complex and time consuming. On the other hand, the presence of outlier in a data set produces deceptive results in the modeling. So it is important to detect and eliminate them to prevent their negative effect on the modeling. This paper describes a new and simple way of constructing fuzzy membership function by using five-number summary of a data set. Five states membership function can be created in this new method. At the same time, if there is any outlier in the data set, it can be detected with the help of this method. Usually box plot is used to identify the outliers of a data set. So along with the new approach, the box plot has also been drawn so that it is understood that the results obtained in the new method are accurate. Several real life examples and their analysis have been discussed with graph to demonstrate the potential of the proposed method. The results obtained show that the proposed method has given good results. In the case of outlier, the proposed method and the box plot method have shown similar results. Primary advantage of this new procedure is that it is not as expensive as neural networks, and genetic algorithms.

关键词： Fuzzy Set Membership Function Five Number Summary Outliers

Plasticity of leaf morphology of Bruguiera sexangula to salinity zones in Bangladesh's Sundarbans

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Journal of Forestry Research 2022年第6期33卷 1857-1866页

作者： md.Salim Azad abdus Subhan Mollick Rawnak Jahan Khan Ranon md.Nabiul Islam Khan md.Kamruzzaman Forestry and Wood Technology Discipline Khulna UniversityKhulna 9208Bangladesh Graduate School of Agriculture Kyoto UniversityKyoto 606-8501Japan

Bruguiera sexangula(Lour.)Poir is an exclusive evergreen mangrove species to the Sundarbans of *** grows well in moderate saline zones with full *** study presents leaf morphological plasticity in *** to saline *** were sampled from different saline zones and various morphological traits were *** results exposed a wide deviations of leaf size parameters:leaf length varied 6.6–17.3 cm;width 2.7–7.8 cm;upper quarter width 2.2–6.5 cm;down quarter width 2.5–7.3 cm;and petiole length 0.17–1.43 *** length was significantly larger in fresh water than in other salinity zones,whereas,leaf width,upper and lower leaf quarters were significantly larger in medium saline *** shape parameters showed a large variation among saline *** base angle was significantly larger in both medium and strong salinity *** angle was significantly greater in medium salinity *** perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline *** index and specific leaf area were maximum in moderate saline *** index was the highest in moderate saline for almost all the parameters *** ordination(PCA)showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity *** results indicate that *** had a plasticity strategy on leaf morphological parameters to salinity in the *** study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation.

关键词： Salinity stress Phenotypic variation Plasticity index Specific leaf area PCA

Heat and Mass Transfer on Non-Newtonian Peristaltic Flow in a Channel in Presence of Magnetic Field: Analytical and Numerical Analysis

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Applied Mathematics 2024年第8期15卷 568-583页

作者： md. Maruf Hasan md. Enamul Karim md. abdus Samad Department of Mathematics Comilla University Comilla Bangladesh Department of Applied Mathematics University of Dhaka Dhaka Bangladesh

A study has been arranged to investigate the flow of non-Newtonian fluid in a vertical asymmetrical channel using peristalsis. The porous medium allows the electrically conductive fluid to flow in the channel, while a uniform magnetic field is applied perpendicular to the flow direction. The analysis takes into account the combined influence of heat and mass transfer, including the effects of Soret and Dufour. The flow’s non-Newtonian behavior is characterized using a Casson rheological model. The fluid flow equations are examined within a wave frame of reference that has a wave velocity. The analytic solution is examined using long wavelengths and a small Reynolds number assumption. The stream function, temperature, concentration and heat transfer coefficient expressions are derived. The bvp4c function from MATLAB has been used to numerically solve the transformed equations. The flow characteristics have been analyzed using graphs to demonstrate the impacts of different parameters.

关键词： Stream Function Mass Transfer Vertical Channel Casson Fluid

Effects of Hall Current and Ohmic Heating on Non-Newtonian Fluid Flow in a Channel due to Peristaltic Wave

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Applied Mathematics 2020年第4期11卷 292-306页

作者： md. Maruf Hasan md. abdus Samad md. Mubarak Hossain Department of Mathematics Comilla University Cumilla Bangladesh Department of Applied Mathematics University of Dhaka Dhaka Bangladesh

In this paper, the study of non-Newtonian fluid flow with heat transfer in a porous asymmetric channel due to peristaltic wave was taken out. Hall current and Ohmic heating effects were introduced in the present study. A Casson non-Newtonian constitutive model was employed for the transport of fluid. Analytical solutions were obtained for stream function, temperature and heat transfer coefficient. The coupled nonlinear equations have also been solved numerically using MATLAB software (by bvp4c function). The influences of many evolving parameters on the flow characteristic have been explained with the help of 2D and 3D plots. Again the obtained results were compared with the results available in the literature and were found in good agreement.

关键词： Ohmic Heating Non-Newtonian Fluid Temperature Field

Predictive car-following scheme for improving traffic flows on urban road networks

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Control Theory and Technology 2019年第4期17卷 325-334页

作者： A.S.M.BAKIBILLAH Mahmudul HASAN md.Mustafijur RAHMAN md.abdus Samad KAMAL School of Engineering Monash UniversityBandar SunwaySelangorMalaysia Technology Operations Department Grameenphone Ltd.DhakaBangladesh Department of Electrical and Electronic Engineering Manarat International UniversityDhakaBangladesh Division of Mechanical Science and Technology Graduate School of Science and TechnologyGunma UniversityJapan

Driving behavior is one of the main reasons that causes bottleneck on the freeway or restricts the capacity of signalized *** paper proposes a car-following scheme in a model predictive control(MPC)framework to improve the traffic flow behavior,particularly in stopping and speeding up of individual vehicles in dense urban traffic under a connected vehicle(CV)*** information received through vehicle-to-vehicle(V2V)communication,the scheme predicts the future states of the preceding vehicle and computes the control input by solving a constrained optimization problem considering a finite future *** objective function is to minimize the weighted costs due to speed deviation,control input,and unsafe *** scheme shares the planned driving information with the following vehicles so that they can make better cooperative driving *** proposed car-following scheme is simulated in a typical driving scenario with multiple vehicles in dense traffic that has to stop at red signals in multiple *** speeding up or queue clearing and stopping characteristics of the traffic using the proposed scheme is compared with the existing car-following scheme through numerical simulation.

关键词： Car-following scheme model predictive control vehicle string connected vehicle environment distributed control

Application of the Improved Kudryashov Method to Solve the Fractional Nonlinear Partial Differential Equations

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Journal of Applied Mathematics and Physics 2019年第4期7卷 912-920页

作者： md. abdus Salam Umme Habiba Department of Mathematics Mawlana Bhashani Science and Technology University Tangail Bangladesh Basic Science Division World University of Bangladesh Dhaka Bangladesh

Our purpose of this paper is to apply the improved Kudryashov method for solving various types of nonlinear fractional partial differential equations. As an application, the time-space fractional Korteweg-de Vries-Burger (KdV-Burger) equation is solved using this method and we get some new travelling wave solutions. To acquire our purpose a complex transformation has been also used to reduce nonlinear fractional partial differential equations to nonlinear ordinary differential equations of integer order, in the sense of the Jumarie’s modified Riemann-Liouville derivative. Afterwards, the improved Kudryashov method is implemented and we get our required reliable solutions where the results are justified by mathematical software Maple-13.

关键词： Improved Kudryashov Method Time-Space Fractional KdV-Burger Equation Travelling Wave Solutions Jumarie’s Modified Riemann-Liouville Derivative

Evaluation of land-use pattern change in West Bhanugach Reserved Forest,Bangladesh,using remote sensing and GIS techniques

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Journal of Forestry Research 2008年第3期19卷 193-198页

作者： md. Abdul Halim abdus shahid Mohammad Shaheed Hossain Chowdhury Mst. Nazmun Nahar md. Shawkat Islam Sohel Nuruddin md. Jahangir Masao Koike Department of Forestry and Environmental Science Shahjalal University of Science and Technology Bangladesh Space Research and Remote Sensing Organization (SPARRSO) Forest Policy Laboratory Department of Forest ScienceFaculty of AgricultureShinshu University Department of Geology and Mining Rajshahi University Department of Civil and Environmental Engineering Shahjalal University of Science and Technology

A study was conducted to investigate the land-use pattern change over a period of 18 years （1988-2006） by using remote sens- ing and Geographical Information System （GIS） technologies, in the West Bhanugach Reserved Forest, a hill forest, in Sylhet Forest Divi- sion of Bangladesh, The images were processed using ERDAS Imagine software. Both supervised and unsupervised approaches were ap- plied and ground control points were collected using a GPS. Maps were prepared using GIS software. Results showed that vegetation cover drastically decreased from the year 1988 to 1996 （l 826 ha to l 714.85 ha）, but increased gradually from the year 1996 to 2006 （l 714.85 ha to l 847.83 ha） due to the initiation of co-management practice involving local communities. Change in bare land was inversely proportionate to the amount of vegetation cover changes unless any other land-uses were converted into bare land. The area of water bodies increased from the year 1988 to 1996 （307.67 ha to 379.53 ha）, but decreased from the year 1996 to 1997, then remained invariabile from the year 1997 to 2006. Some recommendations were also made for applying the RS and GIS techniques to study the land-use pattern change in the Bhanugach Reserved Forest and to create a GIS data base for the study area.

关键词： land-use remote sensing Geographical Information System West Bhanugach Reserved Forest Bangladesh