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An investigation of the effects of synthesized zinc oxide nanoparticles on the properties of water-based drilling fluid

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Petroleum Research 2022年第1期7卷 131-137页

作者： Muhammad Hasibul Ahasan mdFazla Alahi Alvi Nayem Ahmed md.saiful alam Department of Petroleum and Mining Engineering Shahjalal University of Science and TechnologySylhet3114Bangladesh

The deterioration of drilling fluid properties during deep drilling causes problems like inefficient cutting removal,fluid invasion,and shale swelling,which increases non-productive time(NPT)and *** nanoparticles(NPs)based drilling fluid are introduced to address these impediments since these particles prove their advantages in different stages of petroleum exploration and *** developments are concerned with the use of commercial zinc oxide(ZnO)NPs in inorganic KCl salt-based drilling fluid,although application of KCl in drilling fluid arouses environmental *** this study,ZnO NPs prepared in the laboratory are used in water-based drilling fluid(WBDF)to assess the effect of nanoparticles on the properties of drilling fluid at two temperature conditions of 40C and 80C.A base mud is formulated,and ZnO NPs with five different concentrations of 0.05,0.1,0.5,1.0,and 2.0 wt%are mixed with the base *** experimental analysis shows that NPs improve the rheological properties of *** the concentration of NPs was 0.1 wt%,the yield point increased by 61.54%at 40C,and when the concentration of NPs was 0.05 wt%,the yield point increased by 60%at 80***,when the concentration of NPs is 0.05 wt%,10-sec gel strengths are enhanced by 25%and 50%at 40C and 80C,*** API low-pressure low-temperature(LPLT)filter volume is not significantly affected by the addition of NPs in ***,mud cake thickness continuously reduces with the increase of NPs *** result reveals that a superior rheological improvement is achieved at low NPs concentration(0.05 wt%)at higher temperature.

关键词： Drilling fluids Zinc oxide Nanoparticles Rheology Mud cake thickness

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Detection of COVID-19 and Pneumonia Using Deep Convolutional Neural Network

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Computer Systems Science & Engineering 2023年第1期44卷 519-534页

作者： md.saiful Islam Shuvo Jyoti Das md.Riajul alam Khan Sifat Momen Nabeel Mohammed Department of Electrical and Computer Engineering North South UniversityPlot 15Block BBashundharaDhaka1229Bangladesh

COVID-19 has created a panic all around the *** is a contagious dis-ease caused by Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2),originated from Wuhan in December 2019 and spread quickly all over the *** healthcare sector of the world is facing great challenges tackling COVID *** of the problems many have witnessed is the misdiagnosis of COVID-19 cases with that of healthy and pneumonia *** this article,we propose a deep Convo-lutional Neural Network(CNN)based approach to detect COVID+(i.e.,patients with COVID-19),pneumonia and normal cases,from the chest X-ray ***-19 detection from chest X-ray is suitable considering all aspects in compar-ison to Reverse Transcription Polymerase Chain Reaction(RT-PCR)and Computed Tomography(CT)*** deep CNN models including VGG16,InceptionV3,DenseNet121,DenseNet201 and InceptionResNetV2 have been adopted in this pro-posed *** have been trained individually to make particular *** results demonstrate that DenseNet201 provides overall better performance with accuracy,recall,F1-score and precision of 94.75%,96%,95%and 95%*** careful comparison with results available in the literature,we have found to develop models with a higher *** the studies were carried out using a publicly available chest X-ray(CXR)image data-set.

关键词： COVID-19 convolutional neural network deep learning DenseNet201 model performance

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Is the Trade-led Growth Hypothesis Valid for the Kingdom of Saudi Arabia?Evidence from an ARDL Approach

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Fudan Journal of the Humanities and Social Sciences 2021年第3期14卷 445-463页

作者： md.saiful Islam Department of Economics and Finance College of Business AdministrationUniversity of HailHailKingdom of Saudi Arabia

This study examines the trade-led growth(TLG)hypothesis for the Kingdom of Saudi *** time-series annual data for the period 1985-2019,the ARDL approach and Toda-Yamamoto Granger causality test are applied to accomplish the *** ARDL estimation reveals that trade openness positively causes economic growth in both the long and short run,and the TLG hypothesis is found valid for the *** Toda-Yamamoto Granger causality test results have evidenced several unidirectional *** them,trade openness causes economic growth and supports the ARDL finding and hence the TLG hypothesis for the ***,trade openness causes gross fixed capital formation,and the labor force stimulates both economic growth and trade *** findings recommend that the Kingdom may increase its trade to reap further benefits and enhance its income growth.

关键词： Trade-led growth Trade openness Economic growth Labor force Kingdom of Saudi Arabia

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Flexural Strength and Load-Deflection Behaviour of Hybrid Thermoset Composites of Wood and Canola Biopolymers

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Advanced Fiber Materials 2021年第5期3卷 331-346页

作者： Ikra Iftekhar Shuvo md.saiful Hoque md.Shadhin Lovely K.M.Khandakar University of Alberta EdmontonCanada University of Manitoba WinnipegCanada

The study aims to incorporate cellulosic canola(Brassica napus L.)biopolymers with wood biomass to increase flexural strength more than wood fraction alone.A facile fabrication process-at ambient temperature-is employed for ease of producing two different sets of bio-composites utilizing unsaturated polyester resin:pristine composite structures of 100%wood and hybrid composite structures of a canola-wood *** curing process is accompanied by methyl ethyl ketone peroxide(MEKP).Besides the lightweight feature,the hybrid composite structures exhibit maximum flexural strength up to 59.6 and 89.58 MPa at 2.5 and 5%fibre polymer fraction,outperforming the pristine wood composites(49.25 MPa).Also,the bending behaviours of the composite structures are illustrated by the load-deflection curves and the associated SEM micrographs display their fractured and debonded surface at the *** novel canola fibre benefits from its inherent hollow architecture,facilitating an excellent strength to weight ratio for the thermoset ***,canola displays a fibre diameter and density of 79.80(±41.31)μm and 1.34(±0.0014)g/cc,contributing effectively towards the flexure performance and high packing *** breaking tenacity(13.31±4.59 g-force/tex)and tensile strength(174.93±60.29)of canola fibres are comparable to other bast *** synergy among fibre diameters,density and break-ing tenacity creates a good interphase to successfully transfer the external compressive load from the resin matrix to the ***,the two-parameter Weibull distribution model is applied for predicting the failure and reliability probability of composite specimens against a wide range of compressive ***,prioritized SWOT factors have been summa-rized associated with the prospects and key challenges of canola biopolymers-an attempt to strategize the planning and decision-making process for a potential business *** introduction of canola into the pla

关键词： Flexural strength Load-deflection Fibre Composite Weibull distribution

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Human and ecological risks of metals in soils under different land-use types in an urban environment of Bangladesh

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Pedosphere 2020年第2期30卷 201-213页

作者： md.saiful ISLAM md.Kawser AHMED md.Habibullah Al-MAMUN Dennis Wayne EATON Department of Soil Science Patuakhali Science and Technology UniversityDumkiPatuakhali 8602Bangladesh Graduate School of Environment and Information Sciences Yokohama National University79-7 TokiwadaiHodogaya-kuYokohamaKanagawa 240-8501Japan Department of Oceanography University of DhakaDhaka 1000Bangladesh Department of Fisheries University of DhakaDhaka 1000Bangladesh Contract Faculty Rutgers UniversityNew BrunswickNJ 08901-8554USA

Trace metal contamination in soil is of great concern owing to its long persistence in the environment and toxicity to humans and other *** of six potentially toxic trace metals,Cr,Ni,Cu,As,Cd,and Pb,in urban soils were measured in Dhaka City,*** from different land-use types,namely,agricultural field,park,playground,petrol station,metal workshop,brick field,burning sites,disposal sites of household waste,garment waste,electronic waste,and tannery wast,and construction waste demolishing sites,were *** concentration ranges of Cr,Ni,Cu,As,Pb,and Cd in soils were 2.4–1258,8.3–1044,9.7–823,8.7–277,1.8–80,and 13–842 mg kg^-1,*** concentrations of metals were subsequently used to establish hazard quotients(HQs)for the adult *** metal HQs decreased in the order of As>Cr>Pb>Cd>Ni>*** was the most vital exposure pathway of studied metals from soils followed by dermal contact and *** range of pollution load index(PLI)was 0.96–17,indicating severe contamination of soil by trace *** the comprehensive potential ecological risk(PER),soils from all land-use types showed considerable to very high ecological *** findings of this study revealed that in the urban area studied,soils of some land-use types were severely contaminated with trace ***,it is suggested that more attention should be paid to the potential health risks to the local inhabitants and ecological risk to the surrounding ecosystems.

关键词： hazard quotient health risk land use potential ecological risk soil pollution trace metals urban soil

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Invaders’ control on post-disturbance succession in coastal mangroves

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Journal of Plant Ecology 2012年第2期5卷 157-166页

作者： Shekhar R.Biswas md.saiful Islam Khan Azim U.Mallik Department of Ecology and Evolutionary Biology University of Toronto3359 Mississauga RoadMississaugaOntario L5L1C6Canada United Nations Environment Programme-World Conservation Monitoring Centre(UNEP-WCMC) Cambridge CB30DLUK Forest and Landscape LIFECopenhagen University1958 Frederiksberg CDenmark Department of Biology Lakehead University955 Oliver RoadThunder BayOntario P7B 5E1Canada

Aims In recent years,coastal mangroves have been frequently affected by large disturbances(cyclones,hurricanes,flooding and tsunamis)and post-disturbance vegetation is often dominated by small stature mangrove,mangrove-associate and non-mangrove species potentially affecting ecosystem *** on the processes of mangrove vegetation development and recovery(succession)following normal and large disturbances will benefit practitioners in designing robust ecosystem management/restoration *** we propose a conceptual model of disturbance-mediated succession in *** Based on field observations and species’life history traits,we develop conceptual models of mangrove succession under normal disturbance regime and recently experienced increased frequency of large *** evaluate our conceptual models by conducting a scenario testing *** Findings We suggest two predominant processes affecting mangrove succession after disturbance:propagule limitation due to damage of seed producing mature trees and dispersal barrier resulting from biological invasion associated with large *** argue that large disturbances affect mature trees more than the small-stature non-tree(shrubs,herbs and climbers)species creating a larger propagule shortage for mangrove tree species than non-tree ***,large disturbances facilitate invasion of free-floating aquatics,which may interfere with the flow-facilitated propagule dispersal and seedling establishment of mangrove *** a scenario testing experiment,we have shown that similar levels of disturbance impact vegetation development and recovery differently depending on the presence or absence of invasive *** conclude that since biological invasion is one of the major drivers of post-disturbance mangrove succession,the dimension of biological invasion should be included in prediction,management and restoration of mangrove forests.

关键词： biological invasion cryptic ecological degradation dispersal barrier large disturbances mangrove restoration mangrove succession

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Rheology and lubricity characteristics study at different temperatures using synthesized SnO_(2) nanoparticles in KCl free bentonite water base mud

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Petroleum Research 2023年第4期8卷 541-549页

作者： A.B.M.Ariful Bari Khandaker Nayem Ahmed md.saiful alam Department of Petroleum and Mining Engineering Shahjalal University of Science and TechnologySylhet3114Bangladesh Department of Petroleum and Mining Engineering Jashore University of Science and TechnologyJashore7408Bangladesh

Drilling mud is a major concerning element due to its high operational and economic impact on the drilling *** additives are introduced to enhance the efficiency of drilling fluid,but none of them could perfectly achieve their proposed efficacy in drilling *** conceived several nanoparticles(NPs)in drilling fluid to dissolve this *** a singular instance,commercial tin oxide(SnO_(2))nanoparticles were utilized to analyze the influence of NPs on the rheological and filtration properties of inorganic KCl salt-based drilling ***,the effect of SnO_(2) NPs on mud lubricity characteristics is not studied ***,due to the hazardous behavior of KCl,its use is very ***,we consider a KCl-free bentonite water-based mud to avoid any environmental damages from drilling *** also use SnO_(2) NPs that is synthesized in our laboratory by co-precipitation *** addition to rheological and filtration properties,we also investigate the effect of NPs on mud's lubricity that was not considered in the previous *** fluid properties are measured at five different NPs concentrations of 0.10,0.25,0.50,0.75&1.0 wt%,and at six different temperatures of 30,40,50,60,70,and 80°C,while filtration properties are measured using API low-pressure low temperature(LPLT)*** addition of 0.1 wt%SnO_(2) NPs increases plastic viscosity,yield point,10 s gel strength,and 10 min gel strength by 10%,63%,20%,and 14%,*** maximum reduction in lubricity coefficient is found to be 14%at NPs concentration of 1.0 wt%.The NPs concentration of 0.5 wt%yielded a reduction in fluid loss and mud cake thickness by 8.1%and 34%,*** study suggests that SnO_(2) NPs can be employed as an additive to improve the rheology,lubricity,and filtration properties of KCl-free bentonite water-based drilling mud.

关键词： Mud Rheology Lubricity Tin oxide Nanoparticles KCl

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Sensing and Uptake of Nitrogen in Rice Plant: A Molecular View

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Rice science 2019年第6期26卷 343-355页

作者： md.saiful ISLAM Department of Soil Science Patuakhali Science and Technology University Graduate School of Agricultural and Life Sciences The University of Tokyo

As a main feature of plant autotrophy, assimilation of inorganic nitrogen (N) is not only of fundamental interest to the crop, but also a crucial factor in crop productivity. N is the main plant mineral nutrient needed for chlorophyll production and other plant cell components (proteins, nucleic acids and amino acids). I highlighted the novel aspects of N responsive sensors, transporters and signaling molecules recently identified in the monocot rice plant, and discussed their potential roles in N sensing and transporting. Furthermore, over the last couple of years, N sensing has been shown to be affected by different external factors, which act as local signals to trigger systemic signaling coordinated by long-distance transport or mobile signals in plant body. Understanding of this complex regulatory network provides a foundation mechanism for the development of novel strategies to increase the acquisition and transportation efficiency of nitrogen under varying N conditions for rice production.

关键词： rice nitrate signaling gene function

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Effects of Tinospora tuberculata leaf methanol extract on seedling growth of rice and associated weed species in hydroponic culture

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Journal of Integrative Agriculture 2016年第7期15卷 1521-1531页

作者： Farzad Aslani Abdul Shukor Juraimi Muhammad saiful Ahmad-Hamdani Farahnaz Sadat Golestan Hashemi md Amirul alam md Abdul Hakim md Kamal Uddin Department of Crop Science Faculty of Agriculture Universiti Putra Malaysia (UPM) Institute of Tropical Agriculture Universiti Putra Malaysia (UPM) School of Agriculture Science and Biotechnology Faculty of Bioresources and Food Industry Universiti Sultan Zainal Abidin Department of Land Management Faculty of Agriculture Universiti Putra Malaysia (UPM)

The study was conducted to evaluate the responses of rice and rice weed seedlings （barnyardgrass and weedy rice） at the three-leaf stage toTinospora tuberculata leaf methanol extract （3.12, 6.25 and 12.5 g L–1） under hydroponic culture. It shows that the leaf methanol extract had various degrees effects depending on target plant species and each tested index （biomass, root length, shoot length, transpiration volume, chlorophyla, chlorophylb and carotenoid contents）. The effec-tive concentration of the leaf extract capable of reducing 50% of rice growth was higher than those of target weed species. Moreover, the root length was more tolerant to leaf methanol extract in comparison to the other plant parameters measured. A greater reduction was observed in chlorophyla content compared to chlorophylb and carotenoid. The results revealed that the reduction of transpiration volume closely coincided with the magnitude of growth inhibition of tested plants. Ultra-fast liquid chromatography analysis revealed 11 of 32 peaks in chemical proifle, including benzoic acid, caffeic acid, chlorogenic acid, isoorientin, isovitexin, orientin,p-anisic acid, syringic acid,trans-cinnamic acid,trans-ferulic acid, and vitexin have the same retention time with those peaks of the extract. The amount of compounds was present in the range of between 4817 and 115.5 mg kg–1 dry weight （DW）. The concentration-response bioassay of al 11 individual compounds and their equimolar mixture against the seeds of barnyardgrass revealed their contribution in the alelopahic activity ofT. tuberculata leaf extract. The examined compounds and their combination exhibited various degrees of growth inhibitory effects on the early growth of barnyardgrass. Therefore, the speciifc number, concentration, combination and inhibitory activity of bioactive compounds leads to alelopathy activity ofT. tuberculata leaves which could be employable directly as a natural herbicide and its growth inhibitor compounds can be used

关键词： alelochemicals identiifcation and quantiifcation natural herbicide UFLC weed control

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Non-Uniform Doo-Sabin Subdivision Surface via Eigen Polygon

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Journal of Systems Science & Complexity 2021年第1期34卷 3-20页

作者： alam md Nur LI Xin School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China

This paper constructs a new non-uniform Doo-Sabin subdivision scheme via eigen *** authors proved that the limit surface is always convergent and is G1 continuous for any valence and any positive knot intervals under a minor assumption, that λ is the second and third eigenvalues of the subdivision matrix. And then, a million of numerical experiments are tested with randomly selecting positive knot intervals, which verify that our new subdivision scheme satisfies the *** this is not true for the other two existing non-uniform Doo-Sabin schemes in Sederberg, et al.(1998), Huang and Wang(2013). In additional, numerical experiments indicate that the quality of the new limit surface can be improved.

关键词： Doo-Sabin non-uniform splines subdivision

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