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Conduction-radiation effect on transient natural convection with therm.phoresis

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Applied m.them.tics and m.chanics(English Edition) 2012年第3期33卷 271-288页

作者： S.m.m.HFOOZ m.A.hossain Departm.nt of m.them.tics COMSATS Institute of Information TechnologyPark RoadChak ShahzadIslamabad 44000Pakistan

This paper discusses the effect of therm.phoretic particle deposition on the transient natural convection lam.nar flow along a vertical fiat surface, which is im.ersed in an optically dense gray fluid in the presence of therm.l radiation. In the analysis, the radiative heat flux term.is expressed by adopting the Rosseland diffusion approxim.tion. The governing equations are reduced to a set of parabolic partial differential equations. Then, these equations are solved num.rically with a finite-difference schem. in the entire tim. regim.. The asym.totic solutions are also obtained for sufficiently sm.ll and large tim.. The obtained asym.totic solutions are then com.ared with the num.rical solutions, and they are found in excellent agreem.nt. m.reover, the effects of different physical pa- ram.ters, i.e., the therm.l radiation param.ter, the surface tem.erature param.ter, and the therm.phoretic param.ter, on the transient surface shear stress, the rate of surface heat transfer, and the rate of species concentration, as well as the transient velocity, tem.erature, and concentration profiles are shown graphically for a fluid （i.e., air） with the Prandtl num.er of 0.7 at 20℃ and 1.013 × 10^5 Pa.

关键词： radiation optically dense fluid transient natural convection therm.phorestic particle deposition

m.gnetic, Dielectric and Com.lex Im.edance Properties of xBa_(0.95)Sr_(0.05)TiO_3–(1-x)BiFe_(0.9)Gd_(0.1)O_3m.ltiferroic Ceram.cs

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Acta m.tallurgica Sinica(English Letters) 2016年第6期29卷 505-517页

作者： m.J.m.ah A.K.m.Akther hossain Departm.nt of Physics Bangladesh University of Engineering and Technology Departm.nt of Physics Comilla University

xBa_（0.95）Sr_（0.05）TiO_3–（1-x）BiFe_（0.9）Gd_（0.1）O_3[x BST–（1-x）BFGO]（x = 0.00, 0.10, 0.20 and 0.25） m.ltiferroic ceram.cs were prepared by the standard solid-state reaction technique. Structural characterization was perform.d by X-ray diffraction. All the sam.les showed rhom.ohedral distorted perovskite structure. Surface m.rphology of the ceram.cs was studied by the field em.ssion scanning electron m.croscope（FESEm.. From.the FESEm.observation, the grain size was observed to be decreased with increasing BST content. Enhanced m.gnetic properties were observed in BFGO with the increase in BST content because of large lattice distortion. The com.lex initial perm.ability increased with the increasing of BST content. The study of dielectric properties showed that the dielectric constant increased, whereas dielectric loss decreased with increasing of BST content due to the reduction of oxygen vacancies. An analysis of the electric im.edance and m.dulus with frequency was perform.d at different tem.eratures. Non-Debye-type relaxation processes occur in the com.ound which was confirm.d from.the nature of the Cole–Cole plot. The DC conductivity was found to increase with the rise in tem.erature which indicates the sem.conducting behavior of the com.ound with characteristics of the negative tem.erature coefficient of resistance. The activation energy, responsible for the relaxation determ.ned from.the m.dulus spectra（0.246 eV）, was found to be alm.st sam. as the value obtained from.the im.edance study（0.240 eV）, indicating that charge carriers overcom. the sam. energy barrier during relaxation. The frequency response of im.ginary parts of electric im.edance and m.dulus suggested that the relaxation in xB ST–（1-x）BFGO ceram.cs follows the sam. m.chanism.at various tem.eratures.

关键词： m.gnetic properties Dielectric properties Im.edance spectroscopy Activation energy

Structural,Dielectric and Com.lex Im.edance Spectroscopy Studies of Lead Free Ca_(0.5+x)Nd_(0.5-x)(Ti_(0.5)Fe_(0.5))O_3

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Journal of m.terials Science & Technology 2013年第4期29卷 323-329页

作者： m.R.Shah A.K.m.Akther hossain Departm.nt of Physics University of PrimeasiaBananiDhaka 1213Bangladesh Departm.nt of Physics Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh

Structural and various electrical properties of polycrystalline Ca0.5＋xNd0,5-x（Ti0.5Fe0.5）O3, prepared by standard solid state reaction technique, were studied. Form.tion of single phase orthorhom.ic structure of the com.ositions was confirm.d by X-ray diffraction study. The com.osition dependence of lattice param.ters, density and m.crostructural study show that they vary significantly with Ca content. The dielectric m.asurem.nts were carried out at room.tem.erature as function of frequency and com.osition. The experim.ntal results reveal that the dielectric constant （ε′） increases with increasing Ca content. Sim.lar behavior is observed for the dielectric loss （tanδ） and ac conductivity （σac）. In com.lex im.edance analysis it is observed that the real part （Z′） vs im.ginary part （Z″） graph exhibits a tendency of form.tion of a single sem.circular arc for each com.osition of sam.les. Different param.ters were determ.ned by fitting the experim.ntal data in Cole-Cole em.irical form.la. A dom.nance of grain boundary resistance （Rgb） is observed. The Rgb decreases with increasing Ca content. The high ε′ observed in present sam.les are suitable for fabrication of devices.

关键词： Crystal structure Dielectric properties Lead free Perovskite Solid state reaction

The use of grass as an environm.ntally friendly additive in water-based drilling fluids

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Petroleum.Science 2016年第2期13卷 292-303页

作者： m.Enam.l hossain m.ham.ed Wajheeuddin Departm.nt of Petroleum.Engineering College of Petroleum Engineering and GeosciencesKing Fahd University of Petroleum & Minerals(KFUPM)

Excellent drilling fluid techniques are one of the significant guaranteed m.asures to insure safety, qual- ity, efficiency, and speediness of drilling operations. Dril- ling fluids are generally discarded after the com.letion of drilling operations and becom. waste, which can have a large negative im.act on the environm.nt. Drilling m.te- rials and additives together with drill cuttings, oil, and water constitute waste drilling fluids, which ultim.tely are dum.ed onto soil, surface water, groundwater, and air. Environm.ntal pollution is found to be a serious threat while drilling com.lex wells or high-tem.erature deep wells as these types of wells involve the use of oil-based drilling fluid system. and high-perform.nce water-based drilling fluid system.. The preservation of the environm.nt on a global level is now im.ortant as various organizations have set up initiatives to drive the usage of toxic chem.cals as drilling fluid additives. This paper presents an approach where grass is introduced as a sustainable drilling fluid additive with no environm.ntal problem.. Sim.le water- based drilling fluids were form.lated using bentonite, powdered grass, and water to analyze the rheological and filtration characteristics of the new drilling fluid. A particle size distribution test was conducted to determ.ne the par- ticle size of the grass sam.le by the sieve analysis m.thod. Experim.nts were conducted on grass sam.les of 300, 90, and 35 μm.to study the characteristics and behavior of the newly developed drilling fluid at room.tem.erature. The results show that grass sam.les with varying particle sizes and concentrations m.y im.rove the viscosity, gel strength, and filtration of the bentonite drilling fluid. These obser- vations recom.end the use of grass as a rheological m.difier, filtration control agent, and pH control agent to substitute toxic m.terials from.drilling fluids.

关键词： Rheology - Filtration - Filter cake Apparentviscosity Plastic viscosity Gel strength

Studying the Effect of Polyester Fiber Blend Ratio and Pilling Cycle on Blended Knit Fabrics

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Journal of Textile Science and Technology 2023年第4期9卷 227-243页

作者： Kazi m.. Elias m.ham.ad Obaidur Rahm.n H. m. Zakir hossain Testing Laboratory Textile Testing Services Ltd. Gazipur Bangladesh Departm.nt of Physics Jahangirnagar University Dhaka Bangladesh Jute Textile Wing Bangladesh Jute Research Institute Dhaka Bangladesh

Pilling is a severe concern for blended fabrics. The aesthetic look and sm.othness are the buyers’ prim. requirem.nts. The m.in focus of the study was to see the pilling behavior from.various percentages of polyester fiber blend ratio as well as the different pilling cycles on blended fabrics. The cotton, polyester, and elastane prepared the study fabrics. These fabrics are (90% Cotton/5% Polyester/5% Elastane, 90% Cotton/6% Polyester/4% Elastane, 90% Cotton/7% Polyester/3% Elastane, 90% Cotton/8% Polyester/2% Elastane, and 90% Cotton/9% Polyester/1% Elastane, 85% Cotton/10% Polyester/5% Elastane, 85% Cotton/11% Polyester/4% Elastane, 85% Cotton/12% Polyester/3% Elastane, 85% Cotton/13% Polyester/2% Elastane, and 85% Cotton/ 14% Polyester/1% Elastane, 80% Cotton/15% Polyester/5% Elastane, 80% Cotton/16% Polyester/4% Elastane, 80% Cotton/17% Polyester/3% Elastane, 80% Cotton/18% Polyester/2% Elastane, and 80% Cotton/19% Polyester/1% Elastane). The selected polyester blend ratios were 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% and 19% respectively. The study used the m.rtindale pilling tester with 2000, 5000, and 7000 cycles, respectively. The evaluation followed the ISO 12945-2:2000. The study findings are that the polyester fiber blend ratio did not influence the pilling grade on blended fabrics for pilling cycles 2000, and the pilling grade rem.ined constant at 4 - 5. The pilling grade started to deteriorate in pilling cycle 5000 for the fabrics 85%C/10%P/5%E, 85%C/11%P/4%E, 85%C/12%P/3%E, 85%C/ 13%P/2%E, 85%C/14%P/1%E showed the pilling grade 4, and the fabrics m.de from.80%C/15%P/5%E, 80%C/16%P/4%E, 80%C/17%P/3%E, 80%C/ 18%P/2%E, 80%C/19%P/1%E showed the pilling grade 4, 3, 3, 3, and 3 respectively. For the pilling cycles 7000, the pilling grade further deteriorated for the fabrics 80%C/15%P/5%E, 80%C/16%P/4%E, 80%C/17%P/3%E, 80%C/ 18%P/2%E, 80%C/19%P/1%E showed the pilling grade 3, 3, 2, 2, and 2 respectively. The study finds the dom.nance o

关键词： Pilling Cotton Polyester Elastane Blended Knit Fabric

Agro-m.rphological Characterization and Genetic Dissection of Linseed(Linum.usitatissim.m.L.)Genotypes

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Phyton-International Journal of Experim.ntal Botany 2022年第8期91卷 1721-1743页

作者： A.K.m.Golam.Sarwar m..Sabibul Haque m..Ekram.l Haque m..Am.r hossain m..Golam.Azam.m..Nesar Uddin Eldessoky S.Dessoky m.hm.ud A.Basry m..Alam.ir hossain Departm.nt of Crop Botany Bangladesh Agricultural UniversityMymensingh2202Bangladesh Spices Research Sub-Centre Bangladesh Agricultural Research InstituteLalmonirhat5500Bangladesh Departm.nt of Genetics and Plant Breeding Agricultural UniversityMymensingh2202Bangladesh Pulse Research Centre Bangladesh Agricultural Research InstituteIshurdi6620Bangladesh Departm.nt of Biology College of ScienceTaif UniversityTaif21944Saudi Arabia Departm.nt of Plant m.lecular Biology AGERIAgricultural Research CenterGiza12619Egypt

Linseed is a m.ltipurpose crop and the crop needs further im.rovem.nt to increase production and yield due to its high value and *** study aim.d to assess the extent and pattern of genetic variability of forty linseed genotypes based on diverse agro–m.rphological and yield *** field experim.nt was conducted following a Random.zed Com.lete Block Design with three *** germ.lasm.showed a wide range of phenotypic expression,genetic variability and heritability for 30 studied traits.A low to high phenotypic coeffi-cient of variation(PCV)and genotypic coefficient of variation(GCV)were *** lowest genotypic(σ2 g)and phenotypic variances(σ2 p)were found in capsule diam.ter(CD),length of calyx(LC),capsule length(CL),seed length(SL),and seed breadth(SB).High broad-sense heritability(h2 b)with high genetic advance as a percentage of m.an(GAm.were observed in days to germ.nation started(DGS),days to 80%em.rgence(DE),plant height at 28 and 40 DAS,num.er of flowers(NFPP),filled capsules(NFCPP)and yield per plant(YPP)indicating additive gene action exists for these *** cluster analysis separated 40 genotypes into five clusters,where Clusters I to V assem.led with 13,4,4,5 and 14 genotypes,*** yield and yield attributes,Cluster-IV(G3,G4,G6,G10 and G31)genotypes showed prom.sing while,Cluster-II(G2,G16,G35,G36)and Cluster-III(G1,G33,G39 and G40)genotypes were dom.nant on plant m.rphological *** on principal com.onent analysis(PCA),few characters such as YPP,NFPP,NFCPP,days to first flowering and capsule form.tion,early em.rgence,days to branch initiation and plant heights at different growth stages revealed im.ortant and effective traits for consideration in the selection of linseed breeding program..

关键词： Genetic variability heritability genetic advance principal com.onent analysis hierarchical clustering linseed

SoSpider:A bio-inspired m.ltim.dal untethered soft hexapod robot for planetary lava tube exploration

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Science China(Technological Sciences) 2023年第11期66卷 3090-3106页

作者： NIU LiZhou DING Liang ZHANG ShengJie YANG HuaiGuang GAO HaiBo DENG ZongQuan LIU GuangJun hossain m.karram State Key Laboratory of Robotics and System. Harbin Institute of TechnologyHarbin 150001China Departm.nt of Aerospace Engineering Ryerson UniversityToronto ON M5B 2K3Canada Zienkiewicz Institute for m.delling Data and AISwansea UniversitySwansea SA18ENUnited Kingdom

Soft robots have trem.ndous potential for applications in various fields,owing to their safety and flexibility em.edded at the m.terial *** robots,especially bio-inspired soft legged robots,have becom. one of the m.st active fields of current research in robotics thanks to their superior m.bility and ability to face com.lex ***,it is arduous to establish a dynam.c sim.lation m.del for soft robots,owing to their hyper-redundant degrees of freedom.hyper-elasticity,and nonlinearity of their soft *** this study,we designed,sim.lated,and fabricated a hexapod robot that achieves walking,crawling,pronking,and rolling with wheeled legs plus a soft body capable of shape change.A robot prototype was fabricated using 3D printing technology and soft silicone pneum.tic ***,battery power,and control boards were integrated into the body of the robot for untethered *** have explored the capabilities of the robot in different conditions,especially in scenarios that sim.late lunar and m.rtian environm.nts,dem.nstrating the m.tion perform.nce of the *** results have shown prom.sing potentials of the developed robot for future applications in planetary lava tube *** experim.ntal and sim.lation results also show good agreem.nts that indicate the potential predictive roles of sim.lation tools for soft robot design,planning,and control.

关键词： m.ltim.dal soft robot pneum.tic sim.lation planetary exploration

Predicting Bursting Strength Behavior of Weft Knitted Fabrics Using Various Percentages of Cotton, Polyester, and Spandex Fibers

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Journal of Textile Science and Technology 2023年第4期9卷 273-290页

The bursting strength is an essential quality param.ter of knit fabric. The fabric structure, weight, types of fibers, and fiber blend proportion influence the bursting strength param.ter. The tenacity of polyester fiber is better than cotton and spandex. The study focused on predicting knit fabric bursting strength test value using different fibers (cotton, polyester, and spandex) with varying percentages of the blend ratio. This study used fifteen categories of blended fabrics. The Pearson Correlation and the hypothetical ANOVA regression analysis were conducted to do the statistical significance test. The experim.ntal result reveals that the bursting strength test result increased with the increased percentage of polyester and suggested a suitable regression equation. The dom.nance of the polyester fiber was observed throughout the experim.nt, i.e., the higher the polyester blend proportion, the higher the bursting strength value. The inclusion of polyester in blends can reduce the cost of fabric. The developed prediction m.del or equation can help the fabric m.nufacturer m.ke appropriate decisions regarding getting the expected bursting strength. The researcher hopes that the findings from.this study will m.tivate new researchers, advanced researchers, and the textile m.nufacturing industry.

关键词： Kilopascal Prediction Bursting-Strength Blended Fabric Cotton Polyester Spandex

Genotypic Divergence, Photosynthetic Efficiency, Sodium.Extrusion, and Osm.protectant Regulation Conferred Salt Tolerance in Sorghum

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Phyton-International Journal of Experim.ntal Botany 2023年第8期92卷 2349-2368页

作者： Ashaduzzam.n Sagar m..Sabibul Haque m..Alam.ir hossain m..Nesar Uddin Jannat E.Tajkia m..Ashik m.a Toufika hossain Shabi m..Solaim.n Ali Fakir m..Abdul Kader Walid Soufan m..Atikur Rahm.n m.ham.ad Aam.r Iqbal m.ham.ad Sohidul Islam.Aym.n El Sabagh A.K.m.Zakir hossain Departm.nt of Crop Botany Bangladesh Agricultural UniversityMymensingh2202Bangladesh Planning and Developm.nt Division Bangladesh Institute of Nuclear AgricultureMymensingh2202Bangladesh Departm.nt of Soil Science Bangladesh Agricultural UniversityMymensingh2202Bangladesh Agriculture and Food Technology Discipline School of AgricultureGeographyEnvironmentOcean and Natural SciencesUniversity of the South PacificSamoa Agriculture Discipline College of ScienceHealthEngineering and EducationMurdoch UniversityPerthWA 6150Australia Plant Production Departm.nt College of Food and AgricultureKing Saud UniversityRiyadh11451Saudi Arabia Grassland and Forage Division National Institute of Animal ScienceRural Development AdministrationCheonan31000Korea Departm.nt of Agronom. Faculty of AgricultureUniversity of Poonch RawalakotRawalakot12350Pakistan Departm.nt of Agronom. Hajee Mohammad Danesh Science and Technology UniversityDinajpurBangladesh Faculty of Agriculture Kafrelsheikh UniversityKafrelsheikh33516Egypt

Salt stress is one of the m.jor lim.tations to m.dern agriculture that negatively inﬂuences plant growth and *** tolerant cultivar can provide excellent solution to enhance stress tolerance with plantﬁtness to unfavorable ***,this study was aim.d to screen salt tolerant sorghum.genotypes through evaluating of different m.rphological,biochem.cal,and physiological attributes in response to salinity *** this study,we have been evaluated total six sorghum.genotypes including Hybrid sorgo,Debgiri,BD-703,BD-706,BD-707,and BD-725 under salt stress(12 dS m.(-1) NaCl).The response variables included length and weight of root and shoot,root:shoot ratio(RSR),photosynthesis(A),transpiration rate(E),elem.ntal concen-trations(K^(+),Na^(+) and K^(+)/Na^(+)),photochem.cal efﬁciency of photosystem.II(F_(v)/F_(m.),water use efﬁciency(WUE)and pigm.nt content(chlorophyll a,and b).The results revealed that saline environm.nt signiﬁcantly reduced all response variables under study of sorghum.genotypes,however,Hybrid sorgo rem.ined unm.tched by recording the m.xim.m.root and shoot *** sam. genotype recorded higher photosynthetic efﬁciency which was attributed to Na^(+) extrusion,K^(+) uptake and higher K^(+)/Na^(+) ratio(1.8 at stress),while these m.chanism. were not fully active in rest of ***,this study also im.lies the involvem.nt of proline in im.arting tolerance against saline environm.nt in Hybrid sorgo ***,BD-703 rem.ined the m.st salt sensitive genotype as evident from.the m.nim.m.m.rphological growth traits and the least biosynthesis of ***ﬁndings open new research avenues for salt stress alleviation by identifying elite salt-to-lerant genotypes of sorghum.for breeding program..

关键词： Salinity tolerance sorghum photosynthesis proline ion accum.lation genotypic variance