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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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Spatiotemporal variation and mechanisms of temperature inversion in the Bay of Bengal and the eastern equatorial Indian Ocean

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Acta Oceanologica Sinica 2022年第4期41卷 23-39页

作者： K M Azam Chowdhury Wensheng Jiang Guimei Liu md Kawser ahmed Shaila Akhter College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China KeyLab of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao 266100China Department of Oceanography&International Centre for Ocean Governance(ICOG) University of DhakaDhaka 1000Bangladesh National Marine Environmental Forecasting Center Beijing 100081China

In the northern Bay of Bengal,the existence of intense temperature inversion during winter is a widely accepted ***,occurrences of temperature inversion during other seasons and the spatial distribution within and adjacent to the Bay of Bengal are not well *** this study,a higher resolution spatiotemporal variation of temperature inversion and its mechanisms are examined with mixed layer heat and salt budget analysis utilizing long-term Argo(2004 to 2020)and RAMA(2007 to 2020)profiles data in the Bay of Bengal and eastern equatorial Indian Ocean(EEIO).Temperature inversion exists(17.5%of the total 39293 Argo and 51.6%of the 28894 RAMA profiles)throughout the year in the entire study *** shows strong seasonal variation,with the highest occurrences in winter and the lowest in *** winter inversion in the northern Bay of Bengal,two other regions with frequent temperature inversion are identified in this study for the first time:the northeastern part of the Bay of Bengal and the eastern part of the EEIO during summer and *** processes of temperature inversion for different subregions are revealed in the current *** of heat(mean~25 W/m;)below the haline-stratified shallow mixed layer leads to a relatively warmer subsurface layer along with the simultaneous cooling tendency in mixed layer,which controls more occurrence of temperature inversion in the northern Bay of Bengal throughout the *** lower cooling tendency due to net surface heat loss and higher mixed layer salinity leaves the southern part of the bay less supportive to the formation of temperature inversion than the northern *** the EEIO,slightly cooling tendency in the mixed layer along with the subduction of warm-salty Arabian Sea water beneath the cold-fresher Bay of Bengal water,and downwelling of thermocline creates a favorable environment for forming temperature inversion mainly during summer and *** isothermal layer

关键词： temperature inversion Bay of Bengal Argo and RAMA data intrusion of the Arabian Sea water eastern equatorial Indian Ocean penetrative heat below mixed layer depth

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Simulation and Modelling of Water Injection for Reservoir Pressure Maintenance

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Computers, Materials & Continua 2022年第9期72卷 5761-5776页

作者： Rishi Dewan Adarsh Kumar Mohammad Khalid Imam Rahmani Surbhi Bhatia md Ezaz ahmed Department of Physics University of Petroleum&Energy StudiesDehradun 248007UttarakhandIndia Department of Computer Science University of Petroleum&Energy StudiesDehradun 248007UttarakhandIndia College of Computing and Informatics Saudi Electronic UniversityRiyadh 11673Saudi Arabia Department of Information Systems College of Computer Science and Information TechnologyKing Faisal UniversityAl Hasa 36362Saudi Arabia

Water injection has shown to be one of the most successful,efficient,and cost-effective reservoir management *** re-injecting treated and filtered water into reservoirs,this approach can help maintain reservoir pressure,increase hydrocarbon output,and reduce the environmental *** goal of this project is to create a water injection model utilizing Eclipse reservoir simulation software to better understand water injection methods for reservoir pressure maintenance.A basic reservoir model is utilized in this *** simulation designs,the reservoir length,breadth,and thickness may be changed to different *** water-oil contact was discovered at 7000 feet,and the reservoir pressure was recorded at 3000 pounds per square inch at a depth of 6900 *** aquifer chosen was of the Fetkovich type and was linked to the reservoir in the j+*** porosity was estimated to be varied,ranging from 9%to 16%.The residual oil saturation was set to 25%and the irreducible water saturation was set at 20%.The vertical permeability was set at 50 md as a *** Volume Temperature(PVT)data was used to estimate the gas and water characteristics.

关键词： Eclipse water injection reservoir modeling simulation oil saturation

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Assessment of ecological risk for heavy metals in surface sediment of an urban river in a developing country

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International Journal of Sediment Research 2023年第6期38卷 834-846页

作者： md Saiful Islam md Humayun Kabir Mir Mohammad Ali md Towhidul Islam Asfia Niger md Humayun Kabir Zulhilmi Ismail Sujat ahmed Khalid A.Ibrahim Abubakr M.Idris Department of Soil Science Patuakhali Science and Technology University Department of Environmental Science and Resource Management Mawlana Bhashani Science and Technology University Department of Aquaculture Sher-e-Bangla Agricultural University Department of Soil Science Bangabandhu Sheikh Mujibur Rahman Agricultural University Centre for River and Coastal Engineering(CRCE) Universiti Teknologi Malaysia(UTM) Department of Water & Environmental Engineering Faculty of Civil EngineeringUniversiti Teknologi Malaysia(UTM) Environment Center for People & Environ(CPE) Department of Biology College of ScienceKing Khalid University Center for Environment and Tourism Studies and Research King Khalid University Department of Chemistry College of ScienceKing Khalid University Research Center for Advanced Materials Science(RCAMS) King Khalid University

The speed of increasing threats to the riverine water resources makes it more critical to protect the health of Old Brahmaputra River *** current study was done to investigate the concentrations,distributions,sources,and ecological risk of heavy metals in surface sediment from the Old Brahmaputra River,*** were collected from seven sites and analyzed with an inductively coupled plasma-mass spectrometer(ICP-MS).The results showed that mean concentrations(mg/kg) of heavy metals were in the order of nickel(Ni)(44.69)> chromium(Cr)(30.16)> lead(Pb)(19.31)>copper(Cu)(17.84)> cadmium(Cd)(3.94)> arsenic(As)(2.73).The contamination factor(CF),pollution load index(PLI),enrichment factor(EF),and geo-accumulation index(Igeo) indicated low to moderate *** unit analysis revealed that the studied metals from all stations posed low *** sediment of the study river was uncontaminated to moderately contaminated,posing a minimal ecological ***,Cr,Ni,and Pb originated from anthropogenic sources rather than geogenic sources,and caused the severity of *** this regard,pollutant-based intensive monitoring of heavy metals and holistic ecological risk assessments are required to maintain a sound and healthy aquatic environment in the river.

关键词： Heavy metals Sediment quality Ecological risk Old Brahmaputra river Source identification

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Investigation of heat transfer of a building wall in the presence of phase change material(PCM)

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能源与人工环境(英文) 2020年第2期1卷 199-206页

作者： Rafid Jahangir Khan md.Zubayer Hossain Bhuiyan Dewan Hasan ahmed Department of Mechanical and Production Engineering Ahsanullah University of Science and Technology141-142 Love RoadTejgaon Industrial AreaDhakaBangladesh

The energy consumption in buildings for heating,ventilation,and air-conditioning is increasing with the in-creasing demand for thermal *** energy storage with phase change material(PCM)has attracted growing attention for its role in achieving energy conservation in buildings with thermal *** paper investigates the effect of PCM on the heat transfer rate in a building wall and the role of PCM on the indoor thermal comfort of the *** models of building wall fragments were developed for the experimental *** one model,tests were conducted for different positions of the PCM layer in the building wall to identify the optimal position of the PCM layer inside the *** another model,tests were carried out integrating PCM,air gap,and other conventional building materials(brickbat and sand),one at a time,to investigate the role of PCM on the heat transfer rate in the building wall *** results show that placing the PCM layer closer to the heat source gives a low-temperature gain of the cold water bath(indoor state)as compared with the PCM layer near the heat *** PCM,the temperature rise of the cold water bath(indoor state)of the building wall fragment was the lowest,and the slope of the temperature rise of the cold water bath becomes steadier with time i.e.,fewer temperature *** was a significant time delay for the cold water bath to reach a given *** heat required for a unit degree increase in the temperature of the cold water bath was higher and the peak heat flux of the wall was lower relative to the other building materials.

关键词： Phase change material(PCM) Thermal energy storage Building wall fragment Thermal comfort

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Design and Optimization of Photonic Crystal Fiber Based Sensor for Gas Condensate and Air Pollution Monitoring

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Photonic Sensors 2017年第3期7卷 234-245页

作者： md. Ibadul ISLAM Kawsar ahmed Shuvo SEN Sawrab CHOWDHURY Bikash Kumar PAUL md. Shadidul ISLAM Mohammad Badrul Alam MIAH Sayed ASADUZZAMAN Department of Information and Communication Technology (ICT) Mawlana Bhashani Science and Technology University Santosh Tangail 1902 Bangladesh Group of Bio-photomatix Tangail 1902 Bangladesh Department of Software Engineering (SWE) Daffodil International University Sukrabad Dhaka 1207 Bangladesh

In this paper, a hexagonal shape photonic crystal fiber （H-PCF） has been proposed as a gas sensor of which both micro-structured core and cladding are organized by circular air cavities. The reported H-PCF has a single layer circular core which is surrounded by a five-layer hexagonal cladding. The overall pretending process of the H-PCF is completed by using a full vectorial finite element method （FEM） with perfectly matched layer （PML） boundary condition. All geometrical parameters like diameters and pitches of both core and cladding regions have fluctuated with an optimized structure. After completing the numerical analysis, it is clearly visualized that the proposed H-PCF exhibits high sensitivity with low confinement loss. The investigated results reveal the relative sensitivity of 56.65% and confinement loss of 2.31×10^-5 dB/m at the 1.33%tm wavelength. Moreover, effective area, nonlinearity, and V-parameter of the suggested PCF are also briefly described.

关键词： Relative sensitivity confinement loss gas sensor effective area nonlinearity and photonic crystal fiber

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Contributions of shortwave radiation to the formation of temperature inversions in the Bay of Bengal and eastern equatorial Indian Ocean:A modeling approach

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Acta Oceanologica Sinica 2022年第9期41卷 19-37页

作者： K M Azam Chowdhury Wensheng Jiang Changwei Bian Guimei Liu md Kawser ahmed Shaila Akhter College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao266100China Department of Oceanography&International Centre for Ocean Governance(ICOG) University of DhakaDhaka1000Bangladesh National Marine Environmental Forecasting Center Beijing100081China Key Lab of Marine Environment and Ecology of Ministry of Education Ocean University of ChinaQingdao266100China Frontiers Science Center for Deep Ocean Multispheres and Earth System(FDOMES) Ocean University of ChinaQingdao266100China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao266237China Bangladesh Betar Ministry of Information and BroadcastingGovernment of the People’s Republic of BangladeshDhaka1207Bangladesh

Variations in incoming shortwave radiation influence the net surface heat flux,contributing to the formation of a temperature *** effects of shortwave radiation on the temperature inversions in the Bay of Bengal and eastern equatorial Indian Ocean have never been ***,a high-resolution(horizontal resolution of 0.07°×0.07° with 50 vertical layers) Regional Ocean Modeling System(ROMS) model is utilized to quantify the contributions of shortwave radiation to the temperature inversions in the study *** of the mixed layer heat and salt budgets are performed,and different model simulations are *** model results suggest that a 30% change in shortwave radiation can change approximately 3% of the temperature inversion area in the Bay of *** shortwave radiation reduces the net surface heat flux and cools the mixed layer substantially;it also reduces the evaporation rate,causing less evaporative water vapor losses from the ocean than the typical situation,and ultimately enhances haline ***,the rudimentary outcome of this research is that a decrease in shortwave radiation produces more temperature inversion in the study region,which is primarily driven by the net surface cooling and supported by the intensive haline ***,low shortwave radiation eventually intensifies the temperature inversion layer by thickening the barrier *** study could be an important reference for predicting how the Indian Ocean climate will respond to future changes in shortwave radiation.

关键词： mixed layer cooling haline stratification temperature inversion ROMS model shortwave radiation Bay of Bengal eastern equatorial Indian Ocean

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Agro-Morphological, Physico-Chemical and Molecular Characterization of Rice Germplasm with Similar Names of Bangladesh

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Rice science 2016年第4期23卷 211-218页

作者： Mir Sharf Uddin ahmed Mohammad KHALEQUZZAMAN md.Khairul BASHAR Abul Kalam Mohammad SHAMSUDDIN Genetic Resources and Seed Division Bangladesh Rice Research Institute HarvestP lus International Centre for Tropical Agriculture Department of Genetics and Plant Breeding Bangladesh Agricultural University

Thirty-one duplicate and similar named rice germplasms of Bangladesh were studied to assess the genetic variation for the agro-morphological and physico-chemical traits and simple sequence repeat banding patterns during 2009–2012 at Bangladesh Rice Research Institute. The range of variations within the cultivar groups showed higher degree. The principal component analysis showed that the first five components with vector values > 1 contributed 82.90% of the total variations. The cluster analysis grouped the genotypes into four clusters, where no duplicate germplasm was found. The highest number(11) of genotypes was constellated in cluster I and the lowest(3) in cluster II. The intra- and inter-cluster distances were the maximum in cluster I(0.93) and between clusters I and IV(24.61), respectively, and the minimum in cluster IV(0.62) and between clusters I and III(5.07), respectively. The cluster mean revealed that the crosses between the genotypes of cluster I with those of clusters II and IV would exhibit high heterosis for maximum good characters. A total of 350 alleles varied from 3(RM277) to 14(RM21) with an average of 7.8 per locus were detected at 45 microsatellite loci across the 31 rice accessions. The gene diversity ranged from 0.48 to 0.90 with an average of 0.77, and the polymorphism information content values from 0.44(RM133) to 0.89(RM206) with an average of 0.74. RM206, RM21, RM55, RM258 and RM433 were considered as the best markers on the basis of their higher polymorphism information content values. The dendrogram from unweighted pair-group method with arithmetic average clustering also classified the genotypes into four groups, where group IV comprised of 20 genotypes and group III of one genotype, but no duplicate was found. Finally, similar and duplicate named rice germplasms need to be conserved in gene bank as are distinct from each other.

关键词： diversity simple sequence repeat similar name landrace rice agro-morphological and physico-chemical trait

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The response of the upper ocean to tropical cyclone Viyaru over the Bay of Bengal

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Acta Oceanologica Sinica 2019年第1期38卷 61-70页

作者： Mir Kashem md Kawser ahmed Fangli Qiao M A E Akhter K M Azam Chowdhury Department of Oceanography University of Dhaka First Institute of Oceanography Ministry of Natural Resources Department of Physics Khulna University of Engineering & Technology

Better forecast of tropical cyclone(TC) can help to reduce risk and enhance management. The TC forecast depends on the scientific understanding of oceanic processes, air-sea interaction and finally, the atmospheric process. The TC Viyaru is taken as an example, which is formed at the end of 11 May 2013 and sustains up to 17 May 2013 during pre-monsoon season. Argo data are used to investigate ocean response processes by comparing pre-and post-conditions of the TC. Eight oceanic parameters including the sea surface temperature(SST), the sea surface salinity(SSS), and the barrier layer thickness(BLT), the 26°C isotherm depth in the ocean(D26), the isothermal layer depth(ILD), the mixed layer depth(MLD), the tropical cyclone heat potential(TCHP) and the effective oceanic layer for cyclogenesis(EOLC) are chosen to evaluate the pre-and post-conditions of the TC along the track of Viyaru. The values of the SST, D26, BLT, TCHP and EOLC in the pre-cyclonic condition are higher than the post-cyclonic condition, while the SSS, ILD and MLD in the post-cyclonic condition are higher than the pre-cyclonic condition of the ocean due to strong cyclonic winds and subsurface upwelling. It is interesting that the strong intensity of the TC reduces less SST and vice versa. The satisfied real time Argo data is not available in the northern Bay of Bengal especially in the coastal region. A weather research and forecasting model is employed to hindcast the track of Viyaru, and the satellite data from the National Center Environmental Prediction are used to assess the hindcast.

关键词： effective oceanic layer for cyclogenesis, sea surface temperature tropical cyclone tropical cyclone heat potential tropical cyclone viyaru weather research and forecasting model

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Destructive and non-destructive evaluation of concrete for optimum sand to aggregate volume ratio

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1400-1414页

作者： Tarek Uddin MOHAMMED Aziz Hasan MAHMOOD Mohammad Zunaied-Bin-HARUN Jamil ahmed JOY mdAsif ahmed Department of Civil and Environmental Engineering Islamic University of Technology(IUT)Organization of Islamic Cooperation(OIC)Board BazarGazipur 1704Bangladesh Centre for Infrastructure Engineering and Safety School of Civil and Environmental EngineeringThe University of New South WalesSydneyNSW 2052Australia Department of Civil Engineering European University of BangladeshMirpurDhaka 1216Bangladesh

Aggregates are the biggest contributor to concrete volume and are a crucial parameter in dictating its mechanical *** such,a detailed experimental investigation was carried out to evaluate the effect of sand-toaggregate volume ratio(s/a)on the mechanical properties of concrete utilizing both destructive and non-destructive testing(employing UPV(ultrasonic pulse velocity)measurements).For investigation,standard cylindrical concrete samples were made with different s/a(0.36,0.40,0.44,0.48,0.52,and 0.56),cement content(340 and 450 kg/m^(3)),water-to-cement ratio(0.45 and 0.50),and maximum aggregate size(12 and 19 mm).The effect of these design parameters on the 7,14,and 28 d compressive strength,tensile strength,elastic modulus,and UPV of concrete were *** careful analysis demonstrates that aggregate proportions and size need to be optimized for formulating mix designs;optimum ratios of s/a were found to be 0.40 and 0.44 for the maximum aggregate size of 12 and 19 mm,respectively,irrespective of the W/C(water-to-cement)and cement content.

关键词： aggregates non-destructive testing sand-to-aggregate volume ratio(s/a) maximum aggregate size(MAS)

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