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Reproductive Isolating Mechanisms in the Bangladesh Coastal Bullfrog Hoplobatrachus litoralis and Its Congeneric Species Revealed by Crossing Experiments and Examination on Spermatogenesis of the Hybrids

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Asian Herpetological Research 2017年第1期18卷 27-38页

作者： Mahmudul HASAN Mohammed Mafizul ISLAM md. Mukhlesur rahman k.an Ratanasate WANICHANON Atsushi kURABAYASHI Masayuki NUMIDA Amphibian Research Center Hiroshima University 1-3-1 Kagamiyama Higashihiroshima 739-8526 Japan Department of Fisheries Biology and Genetics Bangladesh Agricultural University Mymensingh-2202 Bangladesh Department of Anatomy Phramonkutklao Medical College Rajawithi Rd. Bangkok 10400 Thailand 1-6-15 Ushitaasahi Higashi ku Hiroshima 732-0067 Japan

To elucidate reproductive isolating mechanisms in the Bangladesh coastal bullfrog Hoplobatrachus litoralis and its congeneric species, we performed crossing experiments using three species： H. litoralis, H. tigerinus and H. rugulosus. In addition, we conducted histological observations on spermatogenesis of the hybrids. The reciprocal hybrids between H. litoralis and H. tigerinus developed normally with somewhat lower viability at the metamorphosis stage compared with the controls. Most of the metamorphosed frogs became mature. On the other hand, almost all hybrids between female H. rugulosus and male H. litoralis or H. tigerinus died of underdevelopment at the tadpole stage, and only a few hybrids metamorphosed normally and survived to maturity. The inner structures of the testes of the control H. litoralis and H. tigerinus were completely normal, with seminiferous tubules filled with compact bundles of normal spermatozoa. Those of the reciprocal hybrids between H. litoralis and H. tigerinus were almost normal or slightly abnormal, with seminiferous tubules that contained pycnotic nuclei in addition to normal bundles of normal spermatozoa, which demonstrates slight abnormalities in spermatogenesis. In contrast, the hybrids between female H. rugulosus and male H. litoralis or H. tigerinus had no bundles of spermatozoa nor spermatids in the seminiferous tubules, which indicates entirely abnormal spermatogenesis. Meiotic chromosome figures in the reciprocal hybrids between H. litoralis and H. tigerinus showed slight abnormalities, with the occurrence of univalents and increase of rod-shaped bivalents. These results indicate that H. litoralis and H. tigerinus are not isolated from each other by hybrid inviability nor by hybrid sterility, although the hybrids showed somewhat abnormal spermatogenesis in hybrids and that H. rugulosus is isolated from both H. litoralis and H. tigerinus by incomplete hybrid inviability and complete hybrid sterility.

关键词： Hoplobatrachus reproductive isolation interspecific hybrids spermatogenesis meiotic chromosomes

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Trace Metals Concentrations at the Atmosphere Particulate Matters in the Southeast Asian Mega City (Dhaka, Bangladesh)

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Open Journal of Air Pollution 2015年第2期4卷 86-98页

作者： md. Faridul Islam Syada Sanjida Majumd.r Abdullah Al Mamun md. Badiuzzaman k.an Mohammad arifur rahman Abdus Salam Department of Chemistry University of Dhaka Dhaka Bangladesh Department of Chemistry University of Louisville Louisville USA Department of Environment Sciences Informatics and Statistics Cà Foscari University of Venice Venice Italy Department of Environment Science Bangladesh Agricultural University Mymensingh Bangladesh

Atmospheric particulate matters were collected on quartz fibre filters for 24 hours with a low volume sampler from January 2014 to March 2014 at the Southeast Asian mega city (Dhaka, Bangladesh). Particulate matters samples were analysed for eleven trace metals with inductively coupled plasma mass spectrometer (ICP-MS) at Cà Foscari University of Venice, Italy. Trace metals were extracted from filters with digestion method using a mixture of HNO3 and H2O2. The average concentration of the determined trace metals of As, Cd, Ni, Cu, Pb, Cr, Fe, Mn, Zn, Sband Se were 3.06, 6.28, 3.77, 11.98, 305.6, 9.2, 2057.0, 42.2, 303.3, 5.47 and 2.43 ng·mǅ, respectively. Arsenic concentration is much lower in the atmosphere of Dhaka, though Bangladesh has severe arsenic problem in the ground water. Lead and cadmium concentrations showed decreasing trend in Dhaka compared than previous measurements—but still they have very high levels compared than Europe and USA. There is very limited information for Mn, Sb and Se concentrations in Dhaka air. Correlation studies showed that several trace metals had potential joint sources of origin, e.g., manganese is highly correlated with iron (r2 = 0.97) and nickel (r2 = 0.84), copper (r2 = 0.86);lead with arsenic (r2 = 0.79) and antimony (r2 = 0.78). Enrichment factors analysis was also done with the data base for the respective metals in earth crust and coal fly ash. As and Cu both have combined sources, whereas Cd, Pb and Zn were from coal fly *** metals concentrations in Dhaka city air were much higher than Europe and USA but comparable or slightly lower than other south Asian countries. This is the first extensive study for the eleven trace metals with ICP-MS in Dhaka, Bangladesh.

关键词： Atmospheric Aerosol Particulate Matter Trace Metals Arsenic Lead and Cadmium

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Cardio- and hepato-protective potential of methanolic extract of Syzygium cumini(L.) Skeels seeds:A diabetic rat model study

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Asian Pacific Journal of Tropical Biomedicine 2017年第2期7卷 126-133页

作者： Sumaiya Nahid kishor Mazumd.r Zillur rahman Saiful Islam md. Humayun Rashid Philip Grey kerr Department of Pharmacy University of Science and Technology ChittagongFoy's LakePahartaliChittagong 4202Bangladesh School of Biomedical Sciences Charles Sturt UniversityBoorooma StreetWaggaWaggaNew South Wales 2678Australia Department of Pathology Chittagong Medical College HospitalChittagong 4202Bangladesh

Objective: To evaluate the effect of methanolic extract of Syzygium cumini(L.) Skeels(S. cumini) seeds on the major organs in an animal model of diabetes through biochemical and histopathological ***: The methanolic extracts of S. cumini seeds(100 and 200 mg/kg body weight) were administered to alloxan-induced diabetic rats daily, with fasting blood glucose levels being measured by glucometry at one-day interval for a duration of two weeks. Biochemical assays to evaluate changes in the functions of the heart, liver,pancreas and kidney were carried out. Histopathological changes in the diabetic rat organs(pancreas, liver, heart, kidney and spleen) were also observed after the 14 days of treatment with the ***: Oral administration of methanolic extracts of S. cumini seeds(100 and 200 mg/kg body weight), with gliclazide as a positive control(25 mg/kg), showed beneficial effects including lowering blood glucose levels(P kg, the extracts reversed cardiac and liver damage caused by ***: In addition to the anti-hyperglycemic activity of methanolic extracts of S. cumini seeds, the extracts demonstrates potential to minimize cardiac and hepatic complications.

关键词： Syzygium cumini seeds Diabetes Cardioprotection Hepatoprotection

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Test and performance optimization of nozzle inclination angle and swirl combustor in a low-tar biomass gasifier:a biomass power generation system perspective

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Carbon Resources Conversion 2022年第2期5卷 139-149页

作者： md.Mashiur rahman Agricultural Engineering Division Regional Agricultural Research StationBangladesh Agricultural Research InstituteJamalpur2000Bangladesh DTU Chemical Engineering Technical University of Denmark(DTU)Frederiksborgvej 399DK 4000 RoskildeDenmark

A nozzle inclination angle and swirl combustor inside the low-tar biomass(LTB)gasifier reactor were tested and optimized to evaluate these effects on tar reduction to design tar-free producer *** tar reduction process is mainly based on the concept of a swirling flow created by the nozzle inclination angle,with the inclination angle of 55◦to the radial line,allowing good mixing between pyrolysis gases and gasifying agents.A separate swirl combustor has created large internal annular and reverses flow zones with the help of swirl flow,resulting in homogenized temperature inside the combustor and providing longer residence time;both have a positive effect on the combustion of mixed gasifying air-pyrolysis gases by the thermal cracking in the partial oxidation *** ratio(RR)and combustion degree of volatiles are the two optimization parameters for evaluating the performance of NIA and swirl *** result observed that outstanding tar reduction occurred in this novel *** 86.5 and 12.8%of tar compounds are broken down in the partial oxidation zone and pyrolysis zone using the novel swirl combustor and NIA,respectively;gas outlet has observed producer gas having tar concentration of less than 1%.The optimization results reveal that a lower recycling ratio(recycle gas/gasifying air)and a higher combustion degree of volatiles perform better in biomass ***,this system generated producer gas with the tar concentration at an extremely low level of 7.4 mg/Nm^(3)for a biomass moisture content of 9%and appeared the lower heating value of 4.6–5.1 MJ/Nm^(3).This lower tar concentration might be directly coupled with an internal combustion engine or a gas turbine for power generation.

关键词： Biomass gasification Downdraft moving bed gasifier Nozzle inclination angle Swirl combustor Swirl flow Tar Reduction

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Behaviour of self-centring shear walls——A state of the art review

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Frontiers of Structural and Civil Engineering 2023年第1期17卷 53-77页

作者： Mehdi JAVADI Reza HASSANLI md.Mizanur rahman md.Rajibul kARIM UniSA STEM University of South AustraliaAdelaide 5095Australia

The application of unbonded post-tensioning (PT) in structural walls has led to the development of advanced self-centring (rocking) shear wall systems that has significant advantages, including accelerated construction due to the incorporation of prefabricated elements and segmental construction for different materials (e.g., concrete, masonry, and timber), reduced residual drifts, and little damage upon extreme seismic and wind loads. Concrete, masonry, and timber are often used for the construction of unbonded PT structural wall systems. Despite extensive research since the 1980s, there are no well-established design guidelines available on the shear wall configuration with the required energy dissipation system, joint’s locations and acceptance criteria for shear sliding, confinement, seismic performance factors, PT loss, PT force range and residual drifts of shear walls subjected to lateral loads. In this research a comprehensive state-of-the-art literature review was performed on self-centring shear wall system. An extensive study was carried out to collect a database of 100 concrete, masonry, and self-centring shear wall tests from the literature. The established database was then used to review shear walls’ configurations, material, and components to benchmark requirements applicable for design purposes. The behaviour of concrete, masonry and timber shear walls were compared and critically analysed. The general behaviour, force-displacement performance of the walls, ductility, and seismic response factors, were critically reviewed and analysed for different self-centring wall systems to understand the effect of different parameters including configurations of the walls, material used for construction of the wall (concrete, masonry, timber) and axial stress ratio. The outcome of this research can be used to better understand the behaviour of self-centring wall system in order to develop design guidelines for such walls.

关键词： self-centring shear walls rocking walls energy dissipation seismic performance factors PT loss residual drift

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Self-centring segmental retaining walls—A new construction system for retaining walls

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Frontiers of Structural and Civil Engineering 2021年第4期15卷 980-1000页

作者： Mehdi JAVADI Reza HASSANLI md.Mizanur rahman md.Rajibul kARIM UniSA STEM University of South AustraliaMawson Lakes5095Australia

This paper reports on an experimental study on a new self-centring retaining wall *** post-tensioned segmental retaining walls(PSRWs)were experimentally *** of the walls was constructed using seven T-shaped concrete segments with a dry *** walls were tested under incrementally increasing cyclic lateral *** effect of the wall height,levels of post-tensioning(PT)force,and bonded versus unbonded condition of PT reinforcement on the structural behavior of the PSRWs was *** results showed that such PSRWs are structurally adequate for water retaining *** to the results,increasing the wall height decreases initial strength but increases the deformation capacity of the *** larger deformation capacity and ductility of PSRW make it a suitable structural system for fluctuating loads or deformation,e.g.,*** was also found that increasing the PT force increases the wall’s stiffness;however,reduces its *** residual drift and the extent of damage of the unbonded PSRWs were significantly smaller than those of the bonded *** suggest that this newly developed self-centring retaining wall can be a suitable structural system to retain lateral *** to its unique deformation capacity and self-centring behavior,it can potentially be used for seawall application.

关键词： retaining wall segmental precast concrete unbonded post-tensioning water retaining wall seawall

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Improvement of Rainfall Prediction Model by Using Fuzzy Logic

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American Journal of Climate Change 2020年第4期9卷 391-399页

作者： md. Anisur rahman Department of Mathematics Islamic University Kushtia Bangladesh

This paper presents the improvement of the fuzzy inference model for predicting rainfall. Fuzzy rule based system is used in this study to predict rainfall. Fuzzy inference is the actual procedure of mapping with a given set of input and output through a set of fuzzy systems. Two operations were performed on the fuzzy logic model;the fuzzification operation and defuzzification operation. This study is obtaining two input variables and one output variable. The input variables are temperature and wind speed at a particular time and output variable is the amount of predictable rainfall. Temperature, wind speed and rainfall have to construct eight equations for different categories and which are shows the diagram of the graph. Fuzzy levels and membership functions obtained after minimum composition of inference part of the fuzzifications done for temperature and wind speed are considered as they represent the environmental condition enhance a rainfall occurrence which is effect on agricultural production.

关键词： Fuzzy Logic Membership Function Temperature Wind Speed Predicted Rainfall

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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

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CFD study of turbulent jet impingement on curved surface

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Chinese Journal of Chemical Engineering 2016年第5期24卷 588-596页

作者： Javad Taghinia md.Mizanur rahman Timo Siikonen Aalto University School of EngineeringDepartment of Applied MechanicsFI-00076Finland Hong kong University of Science and Technology Department of Civil and Environmental EngineeringClear Water BayHong KongChina

The heat transfer and flow characteristics of air jet impingement on a curved surface are investigated with computational fluid dynamics(CFD)*** first applied model is a one-equation SGS model for large eddy simulation(LES)and the second one is the SST-SAS hybrid *** models are utilized to study the flow physics in impinging process on a curved surface for different jet-to-surface(h/B)distances at two Reynolds numbers namely,2960 and 4740 based on the jet exit velocity(U_e)and the hydraulic diameter(2B).The predictions are compared with the experimental data in the literature and also the results from RANS k-ε*** show that both models can produce relatively good ***,one-equation model(OEM)produced more accurate results especially at impingement region at lower jet-to-surface *** terms of heat transfer,the OEM also predicted better at different jet-to-surface *** is also observed that both models show similar performance at higher h/B ratios.

关键词： Jet impingement Curved surface RAST one-equation model Large eddy simulation Heat transfer

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Aerial Extent Analysis and Environmental Problems Identification of Matasagar and Sukhsagar Wetlands in Bangladesh Using GIS and Remote Sensing Tools

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Journal of Geographic Information System 2016年第6期8卷 683-691页

作者： md. Zakiur rahman md. Shahedur Rashid Department of Geography and Environmental Science Begum Rokeya University Rangpur Bangladesh Department of Geography and Environment Jahangirnagar University Dhaka Bangladesh

Bangladesh is a land of wetlands. Basically, most of them are freshwater wetlands and have great influence on the primary economic activities such as agriculture and fisheries of the country. Due to its important role in the harmonizing ecosystem, wetlands demand much attention as a significant part of our environment. Matasagar and Sukhsagar are very important historical wetlands of Bangladesh. But those are endangered today due to lack of public awareness of the dangers of their activities to the environment and unbridled profit making activities of the commercial users of the wetlands. Comparisons of maps and Google images from 1933 to present have shown that the forest areas of the wetlands have been progressively destroyed, and these have greatly affected the biodiversity of these areas mentioned. GIS (Geographic Information System) and remote sensing techniques are used to identify the changes in the aerial extent of those wetlands. This study also tried to explore present environmental conditions by in-situ observation. This is high time;some serious steps should be taken to ensure the conservation and preservation of these areas mentioned.

关键词： Historical Wetland Extent Analysis Environment Problems GIS Remote Sensing

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