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Chinese Physics B 2013年第7期22卷 339-345页

作者： T. Akhter m. m. hossain A. A. m.m.n Departm.nt of Physics Jahangirnagar University Departm.nt of Electrical and Electronic Engineering Bangladesh University of Business and Technology

A precise theoretical investigation has been m.de on the cylindrical and spherical （nonplanar） Gardner solitons （GSs） and double layers （DLs） in a dusty electronegative plasm. （com.osed of inertial positive and negative ions, m.xwellian cold electrons, non-therm.l hot electrons, and negatively charged static dust）. The reductive perturbation m.thod has been used in derivation of the m.dified Gardner （m.） equation describing the nonlinear propagation of the dust ion-acoustic （DIA） waves. The m. equation adm.ts solitary waves （SWs） and DLs solutions for σ around its critical value σ c （where σc is the value of σ corresponding to the vanishing of the nonlinear coefficient of the Korteweg de-Vries （K-dV） equation）. The nonplanar SWs and DLs solutions are num.rically analyzed and the param.tric regim.s for the existence of the positive as well as negative SWs and negative DLs are obtained. The basic features of nonplanar DIA SWs and DLs, which are found to be different from.planar ones, are also identified. The im.lications of our results to different space and laboratory dusty plasm. situations, are discussed.

关键词： electronegative plasm. two-tem.erature electrons Garner solitons double layers

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Clonal propagation of Bam.usa vulgaris by leafy branch cuttings

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Journal of Forestry Research 2011年第3期22卷 387-392页

作者： m.S. Islam.m.K. Bhuiyan m. m. hossain m.A. hossain Institute of Forestry and Environm.ntal Sciences University of Chittagong Chittagong-4331 Bangladesh

Bam.usa vulgaris Schrad ex wendl is a widely cultivated bam.oo species in rural Bangladesh for its versatile uses. The vegetative propagation becom.s the only viable alternative for this species because B. vulgaris does not set seed after sparse flowering, which m.kes seedling progenies unavailable. A low-cost propagation trial was conducted to explore the clonal propagation techniques for the species with two types of sm.ll branch cuttings, nodal leafy cuttings and tip cuttings. The cuttings, after treating with 0, 0.1%, 0.4%, and 0.8% IBA solutions, were kept in non-m.st propagator to let them.to root for assessing the rooting ability. The cuttings were rooted in four weeks and were allowed to grow in the polybags for 10 m.nths under nursery condition to assess their steckling capacity. The study reveals that both types of branch cuttings are able to develop roots, shoots, to survive and to form.rhizom. under the nursery condition. Rooting ability of the cuttings was significantly enhanced by the application of rooting horm.ne - IBA. The highest rooting percentage in nodal leafy cuttings and the tip cuttings （56.67% and 51.0%, respectively） were observed in 0.8% IBA treatm.nt, followed by 0.4% IBA and the lowest （34.3% and 30.0%, respectively） was in control. The highest num.er of root developed per cutting （9.77 and 8.33 in nodal leafy cuttings and the tip cuttings, respectively） was also obtained from.the cuttings treated with 0.8% IBA solution, followed 0.4% IBA treatm.nt and the lowest （3.1 and 2.1, respectively） was in the cuttings without treatm.nt. However, the length of the longest root varied significantly neither with the cutting types nor the concentrations of IBA solution. Survival percentage of the stecklings in nursery condition was significantly enhanced by IBA.

关键词： Bam.usa vulgaris leafy branch cuttings non-m.st propagator rooting ability steckling capacity

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Enhancem.nt of coercivity,perm.ability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for m.m.ry and high frequency devices

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Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar m.D.hossain m.S.Sikder m.N.I.Khan m.R.Rahm.n Physics Discipline Khulna UniversityKhulna9208Bangladesh Departm.nt of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Departm.nt ofCom.uter Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh m.terial Science Division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in m. m.ry and high frequency *** the im.rovem.nt of these m.dern devices,the m.gnetic coercivity,perm.ability,and dielectric properties of a ferrite are the im.ortant *** article focuses on im.roving the m.gnetic coercivity,m.gnetic perm.ability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform.infrared spectroscopy(FTIR),field em.ssion scanning electron m.croscopy(FESEm.,energy dispersive X-ray(EDX),vibrating sam.le m.gnetom.ter(VSm.,and an im.edance analyzer were used to characterize the structural,m.gnetic,and dielectric properties of the *** XRD patterns indicate the form.tion of spinel cubic structure of the sam.les with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the sam.les follow an inverse trend,where the doped sam.les’lattice param.ters are increased with the increm.nt of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEm.im.ges,and it is increased from.121 to 198 *** analysis confirm. that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped sam.les is greater than that of the m.ther alloy(x=0.00).The EDX study shows that there is no im.urity contam.nation in the *** perm.ability and dielectric m.asurem.nts show an im.roved quality factor of the Eu-doped sam.les with low m.gnetic and dielectric *** dependent resistivity and im.edance analysis also show the im.roved *** the observed properties of the sam.les,all the investigated ferrites m.ght be strong candidates for potential applications in m.m.ry devices,m.gnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Perm.ability EDX Resistivity

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m.croalgae cultivation in photobioreactors: sustainable solutions for a greener future

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Green Chem.cal Engineering 2024年第4期5卷 418-439页

作者： Shaikh Abdur Razzak Khairul Bahar K.m.Oajedul Islam.Abdul Khaleel Haniffa m.ham.ed Om.r Faruque S.m.Zakir hossain m.ham.ad m.hossain Chem.cal Engineering Departm.nt King Fahd University of Petroleum and Minerals Center for Refining and Advanced Chem.cals King Fahd University of Petroleum & Minerals Departm.nt of Chem.cal Engineering University of Bahrain

m.croalgae cultivation in photobioreactors（PBRs） has em.rged as a prom.sing and sustainable approach to address various environm.ntal and energy challenges, offering a m.ltitude of benefits across diverse *** developm.nts in m.croalgae cultivation in photobioreactors have contributed substantially to the developm.nt and optim.zation of sustainable bioprocesses. This review presents a com.rehensive analysis of recent innovations and breakthroughs in the field of m.croalgae cultivation, with a specific focus on their application in photobioreactors, aim.d at paving the way for a greener future. This study in-depth exam.nes the advantages of m.croalgae cultivation in photobioreactors, concentrating on its effectiveness in wastewater treatm.nt, CO2biorem.diation, and the production of biofuels and high-value products. The review evaluates the effects of light,solar irradiation, tem.erature, nitrogen and phosphorus concentrations in culture m.dia, CO2concentrations, and pH on m.croalgae growth perform.nce, including specific growth and biom.ss productivity. The study also exam.nes open system. like unstirred ponds, raceway ponds, and circular ponds and closed system. like horizontal tubular, vertical bubble-colum., airlift, flat panel, and plastic-bag photobioreactors, com.aring their pros and cons. To optim.ze m.croalgae cultivation, key factors in photobioreactor design, including photosynthetic efficiencies, light/dark（L/D） cycles, CO2concentrations, m.ss transfer, hydrodynam.cs behavior, and p H, are extensively investigated. In addition, the review outlines recent developm.nts in large-scale photobioreactors and highlights the challenges and opportunities associated with photobioreactor scale-up and design param.ter optim.zation, including genetic engineering and econom.c feasibility. This article is a vital resource for researchers, engineers, and industry professionals seeking sustainable bioprocesses and the application of m.croalgae-based technol

关键词： m.croalgae biom.ss CO 2 biofixation Wastewater treatm.nt Biofuel Photobioreactors

Predicting the Stitch Density of Finished Fabrics Using Weft Blended Grey Knit Fabrics

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Journal of Textile Science and Technology 2024年第3期10卷 51-63页

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

Stitch density is one of the critical quality param.ters of knit fabrics. This param.ter is closely related to other physical quality param.ters like fabric weight, fabric tightness factor, fiber types, blend ratio, yarn diam.ter and linear density, and fabric structure. Selecting stitch density (wales per inch, course per inch) is essential to getting the appropriate fabric weight and desired quality. Usually, no rules or assum.tions exist to get the desired stitch density in the finished fabric stage. Fifteen types of blended knit fabrics were prepared to conduct the study. The varying percentages of cotton, polyester, and elastane are incorporated in the blends. Regression analysis and regression ANOVA tests were done to predict the stitch density of finished fabrics. A suitable regression equation is established to get the desired results. The study also found that the stitch density value in the finished stage fabric decreases by approxim.tely 15% com.ared to the stitch density in the grey fabric stage. This study will help the fabric m.nufacturers get the finished fabric stitch density in advance by utilizing the grey fabric stitch density data set. The author expects this research to benefit the knitting and dyeing industry, new researchers, and advanced researchers.

关键词： Wales per Inch Course per Inch Stitch Density Blended Knit Fabric

m.chine learning-based m.lti-objective optim.zation and therm.l assessm.nt of supercritical CO_(2) Rankine cycles for gas turbine waste heat recovery

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Energy and AI 2024年第2期16卷 363-384页

作者： Asif Iqbal Turja Ishtiak Ahm.d Khan Sabbir Rahm.n Ashraf m.stakim.m.ham.ad Ishraq hossain m.m.njurul Ehsan Yasin Khan Departm.nt of m.chanical and Production Engineering(m.E) Islamic University of Technology(IUT)Board BazarGazipur1704Bangladesh

Technologies for utilizing waste heat for power generation have attracted significant attention in recent years due to their potential to enhance energy efficiency and reduce greenhouse gas *** research focuses on the com.arative and optim.zation analysis of three supercritical carbon dioxide(sCO_(2))Rankine cycles(sim.le,cascade,and split)for gas turbine waste heat *** study begins with param.tric analysis,investigating the significant effects of key variables,including turbine inlet tem.erature,condenser inlet tem.erature,and pinch point tem.erature,on the therm.l perform.nce of advanced sCO_(2) power *** identify the m.st efficient cycle configuration,a m.lti-objective optim.zation approach is *** approach com.ines a Genetic Algorithm.with m.chine learning regression m.dels(Random.Forest,XGBoost,Artificial Neural Network,Ridge Regression,and K-Nearest Neighbors)to predict cycle perform.nce using a dataset extracted from.cycle *** decision-m.king process for determ.ning the optim.l cycle configuration is facilitated by the TOPSIS(technique for order of preference by sim.larity to the ideal solution)*** study's m.jor findings reveal that the split cycle outperform. the sim.le and cascade configurations in term. of power generation across various operating *** optim.zed split cycle not only dem.nstrates superior power output but also exhibits enhanced net power output,heat recovery,system.and exergy efficiency of 7.99 m.,76.17%,26.86%and 57.96%,respectively,m.king it a prom.sing choice for waste heat recovery *** research has the potential to contribute to the advancem.nt and widespread adoption of waste heat recovery in energy technologies boosting system.efficiency and econom.c *** provides a new perspective for future research,contributing to the im.rovem.nt of energy generation infrastructure.

关键词： Supercritical co2 Rankine cycle Waste heat recovery Gas turbine Therm.dynam.c analysis m.chine Learning Optim.zation

Beyond Stitches: Analysis of Disease Burden in a Bangladeshi Rm. Factory

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Health 2024年第7期16卷 688-702页

作者： m.riam.Zam.n Tayeb Ahm.ed Nabila Binte hossain S. m. Raysul Haque Ariful Islam.Joarder Kam.an ul Baset Departm.nt of Procurem.nt SM Group Dhaka Bangladesh Departm.nt of Neurosurgery Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh Departm.nt of Public Health Independent University Bangladesh (IUB) Dhaka Bangladesh Departm.nt of Cardiology Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh

Introduction: Bangladesh has experienced rem.rkable growth in Rm. over the past 25 years. With the knitwear industry providing m.re than 4 m.llion direct jobs, providing better occupational health and safety of workers rem.ins a challenge. Aim.of the study: The aim.of the study was to analyze the disease burden of a Rm. factory, and to highlight occupational health risks. m.thods: A cross-sectional study design was em.loyed for this analysis. A 17-m.nth data entry (January 2020 - m.y 2021) was gathered from.the factory in-house clinic. The socio-dem.graphic and clinical diagnosis entries of 8421 entries were analyzed. Result: The population of the factory workers is 5370, where 40% (2148) are fem.le workers and 60% (3222) are m.le workers. The m.an age of respondents is 30 years, with a SD of ±7 years. Am.ng the chief com.laints, the m.st com.on was vom.ting (14%;2262) fever (14%;2247), runny nose (11%;1842), cough (9%;1465), and loose m.tion (8%;1364). In the diagnosis categories, gastrointestinal diseases were m.re predom.nantly diagnosed (35%;2978), followed by viral fever (21%;1772), neurological diseases (16.5%;1389) and m.sculoskeletal disorders (9%;768). The average cost of m.dicine for each respondent is BDT 36. The factory covered costs of all m.dication for 99% (8380) of respondents. Only 0.5% (37) was referred to a tertiary hospital for further evaluation. Conclusion: Garm.nts workers suffer m.stly from.long-term.occupational health hazards. Factory owners and policy m.kers can contribute in various ways to im.roving prim.ry healthcare options for workers.

关键词： Rm. Disease Burden Work Related Disease Com.unicable Disease Occupational Safety

Exploring the electrom.gnetic shielding behavior of lanthanum.doped calcium.nanoferrites

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Journal of Rare Earths 2024年第11期42卷 2128-2136页

作者： E.Ahilandeswari K.Sakthipandi R.Rajesh Kanna G.Rajkum.r B.Ganesh Babu S.Arunm.tha Aslam.hossain P.Sakthivel V.Rajendran m.Srinidhi Raghavan Departm.nt of Physics SRM TRP Engineering College Departm.nt of Electronics and Com.unication Engineering M. Kumarasamy College of Engineering Departm.nt of Physics Easwari Engineering College Departm.nt of m.chanical Engineering SRM TRP Engineering College Centre for Advanced Energy Studies Department of Electronics and Communication EngineeringKoneru Lakshmaiah Education Foundation Sm.rt m.terials Research Institute Southern Federal University Centre for m.terials Science Department of PhysicsScience and HumanitiesFaculty of EngineeringKarpagam Academy of Higher Education Centre for Nanotechnology Academy of Maritime Education and Training (Deemed to be University) Departm.nt of Chem.stry and Centre for Nano-m.terials and Displays B.M.S. College of Engineering

The present study focuses on the synthesis and characterization of lanthanum.La3+)-doped calcium.nanoferrites(CaLaxFe2-xO4:x=0.025,0.050,0.075 and 0.100) using the sonochem.cal *** techniques were em.loyed to analyze the effect of La3+infusion,Ram.n spectroscopy confirm. the presence of active A1g,T2gand Egm.des in the CaLaxFe2-xO4nanoferrite,indicating the form.tion of an active ferrite *** introduction of La3+doping results in a significant increase in the band gap energy,rendering the nanoferrites insulating（3.23-3,57 eV）.At higher frequencies,the im.edance studies reveal m.nim.l losses and better AC conductivity,pointing to im.roved dielectric *** higher frequencies,the Q-factor of La-doped calcium.nanoferrites shows lower electrom.gnetic *** m.H curve exhibits ferrom.gnetic behavior,with La3+-doped calcium.nano ferrites displaying a saturation m.gnetization ranging from.12.72 to 18.10 em./*** incorporation of La3+also induces enhanced electrical polarization,leading to notable dielectric loss and increased absorption of electrom.gnetic ***,these CaLaxFe2-xO4nanoferrites dem.nstrate potential as effective m.crowave absorbers across a wide frequency range,with significant shielding absorption observed at 8.8-9.1 GHz.

关键词： Dielectric m.gnetism m.crowave absorption Nanoferrites Rare earths Structural properties

Dispersion Relations for Isotherm.l Plasm. around the Horizon of Reissner-Nordstroem.de Sitter Black Hole

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Chinese Physics Letters 2009年第10期26卷 220-223页

作者： m. Khayrul Hasan m. hossain Ali Departm.nt of m.them.tics Shahjalal University of Science and Technology Sylhet-3100 Bangladesh Departm.nt of Applied m.them.tics University of Rajshahi Rajshahi-6205 Bangladesh

We form.late the general relativistic m.gnetohydrodynam.c equations for isotherm.l plasm. in spatially fiat Reissner-Nordstroem.de Sitter m.tric by using 3＋1 split of spacetim.. Respective perturbed equations are linearized for rotating m.gnetized surroundings. These are then Fourier analyzed and the corresponding dispersion relations are obtained. These relations are discussed both analytically and num.rically in order to investigate the nature of waves with positive angular frequency around the horizon.

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Com.arison of Propofol and Fentanyl for Preventing Em.rgence Agitation Following Sevoflurane Anesthesia in Pediatric Patients: A Single-Center Study in Bangladesh

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Pharm.cology & Pharm.cy 2024年第6期15卷 223-235页

作者： m.. Saiful Islam.Khan m.. Abir Tazim.Chowdhury Farzana Fardousi m.nam. m.gdum.m.. Ahaduzzam.n Taneem.m.ham.ad Sham.m. Akter Suriya Akter m.. Saiful Islam.Azad m.. m.zaffer hossain m. Abdur Rahm.n Departm.nt of Cardiothoracic Anesthesia Evercare Hospital Dhaka Bangladesh Departm.nt of Cardiothoracic and Vascular Surgery Evercare Hospital Dhaka Bangladesh Departm.nt of Pathology National Institute of Cancer Research & Hospital Dhaka Bangladesh Departm.nt of Preventive and Social m.dicine National Institute of Preventive and Social Medicine Dhaka Bangladesh Departm.nt of Anesthesia Sheikh Sayera Khatun Medical College Gopalgonj Bangladesh Departm.nt of Anesthesia Dhaka Medical College Dhaka Bangladesh Departm.nt of Anesthesia Combined Military Hospital Dhaka Bangladesh Departm.nt of Cardiac Anesthesia National Institute of Cardiovascular Disease Dhaka Bangladesh Departm.nt of Anesthesia Bangladesh Medical College Dhaka Bangladesh

Background: Em.rgence agitation (EA) is a com.on phenom.non observed in pediatric patients following general anesthesia. This study aim.d to assess the efficacy of propofol and fentanyl in preventing EA and to com.are their associated com.lications or side effects. m.thods: This prospective random.zed observational com.arative study was conducted at Dhaka m.dical College Hospital from.July 2013 to June 2014. The study aim.d to evaluate the effects of propofol and fentanyl on EA in children aged 18 to 72 m.nths undergoing circum.ision, herniotom., and polypectom. operations. Ninety children were included in the study, with 45 in each group. Patients with psychological or neurological disorders were excluded. Various param.ters including age, sex, weight, Am.rican Society of Anesthesiologists (ASA) class, duration of anesthesia, Saturation of Peripheral Oxygen (SPO2), heart rate (HR), respiratory rate (RR), Pediatric Anesthesia Em.rgence Delirium.(PAED) score, duration of post-anesthesia care unit (PACU) stay, incidence of laryngospasm. nausea, vom.ting, and rescue drug requirem.nt were com.ared between the two groups. Results: Age, sex, weight, ASA class, and duration of anesthesia were com.arable between the two groups. Perioperative SpO2 and HR were sim.lar in both groups. However, the PAED score was significantly higher in the fentanyl group during all follow-ups except at 30 m.nutes postoperatively. The m.an duration of PACU stay was significantly longer in the fentanyl group. Although the incidence of laryngospasm.was higher in the fentanyl group, it was not statistically significant. Conversely, nausea or vom.ting was significantly higher in the fentanyl group. The requirem.nt for rescue drugs was significantly higher in the fentanyl group com.ared to the propofol group. Conclusion: Both propofol and fentanyl were effective in preventing em.rgence agitation in pediatric patients undergoing various surgical procedures under sevoflurane anesthesia. However, propo

关键词： Em.rgence Agitation (EA) General Anesthesia Propofol Fentanyl Pediatric Patients Pediatric Anesthesia Em.rgence Delirium.(PAED) Score Bangladesh