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Assessment of heavy metal contamination in the sur?cial sediments from the lower Meghna River estuary, Noakhali coast, Bangladesh

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International Journal of Sediment Research 2021年第3期36卷 384-391页

作者： Mohammad Abdul Momin Siddique Mahfuzur rahman Shahriar md.arifur rahman md.Rubel Hassan Zeenath Fardous Muhammed Alamgir Zaman Chowdhury Mohammad Belal Hossain Department of Oceanography Noakhali Science and Technology University Agrochemical and Environmental Research Division Institute of Food and Radiation Biology Atomic Energy Research Establishment 5. Department of Fisheries and Marine Science Noakhali Science and Technology University Department of Environmental Science and Disaster Management Noakhali Science and Technology University University of South Bohemia in Ceske Budejovice Faculty of Fisheries and Protection of Waters South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses Research Institute of Fish Culture and Hydrobiology

Sediment samples were collected from ten selected sites of the lower Meghna River estuary, and six heavy metals were analyzed with Atomic Absorption Spectrophotometry(AAS) to assess the contamination level and the metals’ association with sediment grain size. The current results revealed that the mean concentrations of the studied metals were ranked in descending order of iron(Fe)(1.29 ? 103 mg/kg) > zinc(Zn)(42.41 mg/kg) > lead(Pb)(12.48 mg/kg) > chromium(Cr)(10.59 mg/kg) > copper(Cu)(6.22 mg/kg) > cadmium(Cd)(0.28 mg/kg). The geo-accumulation, contamination, and pollution load indexes suggested that the lower Meghna river estuary was not contaminated by Fe, Zn, Pb, Cr, and *** mean size of the sediment ranged from 28.92 to 126.2 mm, and the Pearson correlation coefficient showed a significant association between Fe and Pb(coefficient of determination, r2? 0.836; p < 0.05),and no significant correlation was found between individual metals and grain size, indicating no or low influence on the metals distribution.

关键词： Metal pollution Pollution load index Grain size Trace metals

A multidisciplinary method to assess the reproductive biology of Mystus bleekeri

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Aquaculture and Fisheries 2023年第3期8卷 280-287页

作者： Tamanna Sultana Sabuj Kanti Mazumder Jannatul Kubra Nurnobi Nishad Sarker Mohammad Ibrahim Khalil Simon Kumar Das md.arifur rahman Khan md.Tawheed Hasan Department of Aquatic Resource Management Faculty of FisheriesSylhet Agricultural UniversitySylhet3100Bangladesh Department of Genetics and Fish Breeding Faculty of FisheriesBangabandhu Sheikh Mujibur Rahman Agricultural UniversityGazipur1706Bangladesh Department of Fish Health Management Faculty of FisheriesSylhet Agricultural UniversitySylhet3100Bangladesh School of Environmental and Natural Resource Sciences Faculty of Science and TechnologyUniversiti Kebangsaan MalaysiaUKM BangiSelangor43600Malaysia Department of Agronomy Faculty of AgricultureBangabandhu Sheikh Mujibur Rahman Agricultural UniveristyGazipur1706Bangladesh Department of Aquaculture Faculty of FisheriesSylhet Agricultural UniversitySylhet3100Bangladesh

The study aims to afford a deeper knowledge on reproductive biology of Mystus bleekeri from Surma River,Bangladesh in a multidisciplinary ***,the species is in demand as food and ornamental fish in Bangladesh but still now comprehensive details on reproductive biology of this species is *** 600 fish samples were derived from commercial catches from July 2018 to June *** differences in sex ratio,size distribution,condition factor(Kn),fecundity,gonadosomatic index and gonadal maturation cycle were *** results showed 384(64%)female and 216(36%)male with an overall sex ratio of 1.77:1(female:male).Mean total length(TL)and body weight(BW)of all fish studied were 14.85±3.38 cm TL and 27.54±15.76 g,*** Kn varied with length groups,the highest(1.45±0.23)and lowest(0.89±0.18)values obtained in 16.0-16.9 and 10.0-10.9 cm TL groups,*** highest Kn was documented in October while the lowest was in *** GSI values showed two peaks in July and November for both the *** fecundity was found to vary from 1120 to 14790 eggs with average value of 4968±3047 with 14.4-18.3 cm in TL and 19.97-34.7g in *** relationship of fecundity with TL and BW was F=1.385TL13.405,r^(2)=0.885 and F=5.201BW^(4.827),r^(2)=*** behavior of spawning together with allochronic oocytes development has also been found through *** results of this study could be used for predicting the response of populations of fish in Surma River and/or other where to human interferences and environmental change.

关键词： Condition factor Gonadal cycle Gonadosomatic index Mystus bleekeri Sex ratio

Remote condition monitoring of rail tracks using distributed acoustic sensing(DAS):A deep CNN-LSTM-SW based model

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Green Energy and Intelligent Transportation 2024年第5期3卷 70-85页

作者： md.arifur rahman Suhaima Jamal Hossein Taheri The Laboratory for Advanced Non-Destructive Testing In-situ Monitoringand Evaluation(LANDTIE)Department of Manufacturing EngineeringGeorgia Southern UniversityStatesboro 30458GAUSA Information Technology Department Georgia Southern UniversityStatesboro 30458GAUSA

Railroad condition monitoring is paramount due to frequent passage through densely populated *** significance arises from the potential consequences of accidents such as train derailments,hazardous materials leaks,or collisions which may have far-reaching impacts on communities and the surrounding *** a solution to this issue,the use of distributed acoustic sensing(DAS)-fiber optic cables along railroads provides a feasible tool for monitoring the health of these extended ***,analyzing DAS data to assess railroad health or detect potential damage is a challenging *** to the large amount of data generated by DAS,as well as the unstructured patterns and substantial noise present,traditional analysis methods are ineffective in interpreting this *** paper introduces a novel approach that harnesses the power of deep learning through a combination of CNNs and LSTMs,augmented by sliding window techniques(CNN-LSTM-SW),to advance the state-of-the-art in the railroad condition monitoring *** well as it presents the potential for DAS and fiber optic sensing technologies to revolutionize the proposed CNN-LSTM-SW model to detect conditions along the rail track *** insights from the data of High tonnage load(HTL)-a 4.16 km fiber optic and DAS setup,we were able to distinguish train position,normal condition,and abnormal conditions along the ***,our investigation demonstrated that the proposed approaches could serve as efficient techniques for processing DAS signals and detecting the condition of railroad infrastructures at any remote distance with DAS-Fiber optic cable ***,in terms of pinpointing the train's position,the CNN-LSTM architecture showcased an impressive 97%detection *** a sliding window,the CNN-LSTM labeled data,the remaining 3%of misclassified labels have been improved dramatically by predicting the exact locations of each type of ***,these prop

关键词： Distributed acoustic sensing(DAS)-Fiber optic cable Railroad condition monitoring and anomaly detection High tonnage load(HTL) Convolutional neural network-long short-term memory-sliding window(CNN-LSTM-SW)

Surfactant and nanoparticle synergy:Towards improved foam stability

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Petroleum 2023年第2期9卷 255-264页

作者： arifur rahman Farshid Torabi Ezeddin Shirif Petroleum Systems Engineering Faculty of Engineering and Applied ScienceUniversity of ReginaReginaSK S4S 0A2Canada Petroleum and Mining Engineering School of Applied Science&TechnologyShahjalal University of Science and TechnologySylhet3114Bangladesh

Surfactant foam stability gets a lot of interest while posing a significant obstacle to many industrial *** of the viable solutions for addressing gas mobility concerns and boosting reservoir fluid sweep efficiency during solvent-based enhanced heavy oil recovery processes is foam *** synergistic effect of nanoparticles and surfactants in a porous reservoir media can help create a more durable and sturdier *** study aims to see how well a combination of the nanoparticles(NPs)and surfactant can generate foam for controlling gas mobility and improving oil *** research looked at the effects of silicon and aluminum oxide nanoparticles on the bulk and dynamic stability of sodium dodecyl surfactant(SDS)-foam in the presence and absence of *** foam height,liquid drainage,half-decay life,nanoparticle deposition,and bubble size distribution of the generated foams with time were used to assess static foam stability in the bulk phase,while dynamic stability was studied in the *** understand the processes of foam stabilization by nanoparticles,the microscopic images of foam and the shape of bubbles were *** nanoparticles were applied in foamability testing in bulk and dynamic phase,the foam generation and stability were improved by 23%and 17%,*** comparison to surfactant alone,adding nanoparticles to surfactant solutions leads to a more significant pressure drop of 17.34 psi for SiO_(2)and 14.86 psi for Al_(2)O_(3)NPs and,as a result,a higher reduction in gas mobility which ultimately assists in enhancing oil recovery.

关键词： Foam stability Nanoparticles Surfactant Foam decay Pressure drop Enhanced oil recovery Etc

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Nanoparticle-stabilized CO2 foam flooding for enhanced heavy oil recovery: A micro-optical analysis

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Petroleum 2024年第4期10卷 696-704页

作者： arifur rahman Ezeddin Shirif Farshid Torabi Petroleum Systems Engineering Faculty of Engineering and Applied Science University of Regina Petroleum and Mining Engineering School of Applied Science & Technology Shahjalal University of Science and Technology

Surfactant flooding is a well-known chemical approach for enhancing oil recovery. Surfactant flooding has the disadvantage that it cannot withstand the harsh reservoir conditions. Improvements in oil recovery and release are made possible by the use of nanoparticles and surfactants and CO2co-injection because they generate stable foam, reduce the interfacial tension（IFT） between water and oil, cause emulsions to spontaneously form, change the wettability of porous media, and change the characteristics of flow. In the current work, the simultaneous injection of SiO2, Al2O3nanoparticles, anionic surfactant SDS, and CO2in various scenarios were evaluated to determine the microscopic and macroscopic efficacy of heavy oil recovery. IFT（interfacial tension） was reduced by 44% when the nanoparticles and SDS（2000 ppm） were added, compared to a reduction of roughly 57% with SDS only. SDS-stabilized CO2foam flooding, however, is unstable due to the adsorption of SDS in the rock surfaces as well as in heavy oil. To assess foam's potential to shift CO2from the high permeability zone（the thief zone） into the low permeability zone, directly visualizing micromodel flooding was successfully executed（upswept oil-rich zone）. Based on typical reservoir permeability fluctuations, the permeability contrast（defined as the ratio of high permeability to low permeability） for the micromodel flooding was selected. However, the results of the experiment demonstrated that by utilizing SDS and nanoparticles, minimal IFT was reached. The addition of nanoparticles to surfactant solutions, however, greatly boosted oil recovery,according to the findings of flooding studies. The ultimate oil recovery was generally improved more by the anionic surfactant（SDS） solution including nanoparticles than by the anionic surfactant（SDS） alone.

关键词： Micromodel CO 2 foam Surfactant Nanoparticles Interfacial tension Heavy oil

Capturing transition and non-transition flows with a new shear stress transport model

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Chinese Journal of Aeronautics 2023年第3期36卷 121-136页

作者： md Mizanur rahman School of Mechanical Engineering Hangzhou Dianzi UniversityHangzhou 310018China

A new Shear Stress Transport(SST)k-ω model is devised to integrate salient features of both the non-transitional SST k-ω model and correlation-based γ-Re_(θ) transition *** exceptionally simplified approach is applied to extend the New SST(NSST)model capabilities toward transition/non-transition ***’s stress-intensity factor R_(b)=|-uv|/k can be parameterized with the wall-distance dependent Reynolds number Re_(y)=√ky/v;however,as the Re_(y)is replaced by a“flow-structure-adaptive”parameter R_(μ)=v_(T)/v,the resulting R_(b)is capable of capturing various transition phenomena *** prospective stress-intensity parameter R_(b)=R_(b)(Re_(y),R_(μ))is incorporated in the constitutive relations for eddy-viscosity v_(T) and production term P_(k).The proposed formulation is intrinsically plausible,having a dramatic impact on the prediction of bypass,separation-induced and natural transitions together with non-transitional *** extra viscous-production term P_(k)^(lim) is added with the k-equation to ensure proper generation of k at the viscous sublayer when computing separation-induced transition over a Low-Reynolds Number(LRN)*** demonstrate that the NSST k-ω model maintains an excellent consistency with both SST k-ω and γ-Re_(θ) models.

关键词： γ-Re_(θ)model Non-transition Stress-intensity parameter SST model Transition

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An Improved Encoder-Decoder CNN with Region-Based Filtering for Vibrant Colorization

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Computer Systems Science & Engineering 2023年第7期46卷 1059-1077页

作者： Mrityunjoy Gain md.arifur rahman Rameswar Debnath MrimMAlnfiai Abdullah Sheikh Mehedi Masud Anupam Kumar Bairagi Computer Science and Engineering Discipline Khulna UniversityKhulna 9208Bangladesh Department of Information Technology College of Computers and Information TechnologyTaif UniversityTaif 21944Saudi Arabia Department of Computer Science College of Computers and Information TechnologyTaif UniversityTaif 21944Saudi Arabia

Colorization is the practice of adding appropriate chromatic values to monochrome photographs or videos.A real-valued luminance image can be mapped to a three-dimensional color ***,it is a severely ill-defined problem and not has a single *** this paper,an encoder-decoder Convolutional Neural Network(CNN)model is used for colorizing gray images where the encoder is a Densely Connected Convolutional Network(DenseNet)and the decoder is a conventional *** DenseNet extracts image features from gray images and the conventional CNN outputs a^(*)b^(*)color *** to a large number of desaturated color components compared to saturated color components in the training images,the saturated color components have a strong tendency towards desaturated color components in the predicted a^(*)b^(*)*** solve the problems,we rebalance the predicted a^(*)b^(*)color channel by smoothing every subregion individually using the average filter.2 stage k-means clustering technique is applied to divide the *** we apply Gamma transformation in the entire a^(*)b^(*)channel to saturate the *** compare our proposed method with several existing *** the experimental results,we see that our proposed method has made some notable improvements over the existing methods and color representation of gray-scale images by our proposed method is more plausible to ***,our suggested approach beats other approaches in terms of Peak Signal-to-Noise Ratio(PSNR),Structural Similarity Index Measure(SSIM)and Histogram.

关键词： Colorization DenseNet desaturation k-means

Sensitivity analysis of the DehumReq model to evaluate the impact of predominant factors on dehumidification requirement of greenhouses in cold regions

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Information Processing in Agriculture 2023年第2期10卷 216-228页

作者： md Sazan rahman Huiqing Guo Department of Mechanical Engineering University of Saskatchewan57 Campus driveSaskatoonSK S7N 5A9Canada Department of Bioresource Engineering McGill UniversityMacdonald Stewart Building21111 Lakeshore RoadSainte-Anne-de-BellevueQC H9X 3V9Canada

In this study,the sensitivity of a novel dehumidification requirement model(DehumReq)is analyzed to evaluate the effect of the predominant factors on the dehumidification needs of the *** hourly dehumidification demand and sensitivity coefficient(SC)are estimated for three different seasons:warm(July),mild(May),and cold(November),by using the local sensitivity analysis *** on SC values,the solar radiation,air exchange,leaf area index(LAI),and indoor setpoints(temperature,relative humidity(RH),and water vapor partial pressure(WVPP))have significant impact on the dehumidifi-cation needs,and the impact varies from season to *** parameters have a higher SC in summer,whereas solar radiation and LAI have a higher SC in mild *** dehumidification load increases 4 times of its base value with increasing solar radiation by 200 W/m^(2),and the highest LAI(10)caused 5 times increment of the *** changing of WVPP from its base value(1.5 kPa)to maximum(2.9 kPa)reduces the load 70%in *** exchange was found to be the most crucial parameter because it is the main dehumidification approach that has a large range and is easily adjustable for any *** air exchange by ventilation or infiltration will reduce the dehumidification load to zero in May and November and minimizes it to only nighttime load in *** the other parameters,higher ambient air RH and indoor air speed will result in higher the dehumidification load;whereas higher inner surface condensation will result in lower dehumidifi-cation *** result of this study will assist in the selection of the most efficient moisture control strategies and techniques for greenhouse humidity control.

关键词： Greenhouse Dehumidification DehumReq model Sensitivity analysis Solar radiation Air exchange

Low Melting Temperature Liquid Metals and Their Impacts on Physical Chemistry

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Accounts of Materials Research 2021年第8期2卷 577-580页

作者： Kourosh Kalantar-Zadeh md.arifur Rahim Jianbo Tang School of Chemical Engineering University of New South Wales(UNSW)KensingtonNSW 2052Australia

Low-melting-temperature(LMT)metals and alloys based on post-transition metals,frequently dubbed as“liquid metals”,are enigmatic *** they have been around for thousands of years,and we have continuously been fascinated by what they are,our knowledge about them is still *** the reason is that most electromagnetic waves or even electron beams can hardly penetrate through liquid metals and we tend to ignore what we cannot directly observe.

关键词： materials. metals alloys