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Allometric relationship for estimating above-ground biomass of Aegialitis rotundifolia Roxb. of Sundarbans mangrove forest, in Bangladesh

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Journal of Forestry Research 2012年第1期23卷 23-28页

作者： Mohammad Raqibul hasan Siddique Mahmood Hossain md. Rezaul Karim Chowdhury Forestry and Wood Technology Discipline Khulna University Khulna-9208 Bangladesh

Tree biomass plays a key role in sustainable management by providing different aspects of ecosystem. Estimation of above ground biomass by non-destructive means requires the dex;elopment of allometric equations. Most researchers used DBH （diameter at breast height） and TH （total height） to develop allometric equation for a tree. Very few spe- cies-specific allometric equations are currently available for shrubs to estimate of biomass from measured plant attributes. Therefore, we used some of readily measurable variables to develop allometric equations such as girth at collar-height （GcH） and height of girth measuring point （GMH） with total height （TH） for A. rotundifolia, a mangrove species of Sundarbans of Bangladesh, as it is too dwarf to take DBH and too ir- regular in base to take Girth at a fixed height. Linear, non-linear and logarithmic regression techniques were tried to determine the best re- gression model to estimate the above-ground biomass of stem, branch and leaf. A total of 186 regression equations were generated from the combination of independent variables. Best fit regression equations were determined by examining co-efficient of determination （R：）, co-efficient of variation （Cv）, mean-square of the error （Ms^r）, residual mean error （Rmax）, and F-value. Multiple linear regression models showed more efficient over other types of regression equation. The performance of regression equations was increased by inclusion of GMn as an independ- ent variable along with total height and GCH.

关键词： Aegialitis rotundifolia allometry biomass mangroves sundarbans

Pressure-dependent physical properties of cubic SrΒO3(Β=Cr,Fe)perovskites investigated by density functional theory

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Chinese Physics B 2020年第12期29卷 212-220页

作者： md.Zahid hasan md.Rasheduzzaman Khandaker Monower Hossain Department of Electrical and Electronic Engineering International Islamic University ChittagongKumiraChittagong-4318Bangladesh Department of Materials Science and Engineering University of RajshahiRajshahi-6205Bangladesh

We perform the first-principles investigations of the structural,elastic,electronic,and optical properties of SrBO3(B=Cr,Fe)perovskites under pressure based on density functional theory(DFT).This is the first detailed pressure-dependent study of the physical properties for these *** calculated structural parameters are consistent with the existing experimental results and slightly decrease with the application of *** mechanical properties are discussed in detail and reveal that the SrCrO3 is harder than *** pressure,these compounds behave like half-metals,confirmed by their band structure and density of *** the SrCrO3 retains its half-metallic nature under pressure,SrFeO3 becomes metallic for both up-spin and down-spin *** charge density and bond overlap population reveal the covalent nature of Cr–O bond and Fe–O bond in the studied *** optical properties of SrBO3,also discussed for the first time,reveal some interesting results.

关键词： density functional theory(DFT) effects of pressure electronic band structure optical properties

Single polarization photonic crystal fiber filter based on surface plasmon resonance

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Frontiers of Optoelectronics 2019年第2期12卷 157-164页

作者： md. Nazmul HOSSEN md. FERDOUS Kawsar AHMED md. Abdul KHALEK Sujan CHAKMA Bikash Kumar PAUL Department of Information and Communication Technology(ICT) Mawlana Bhashani Science and Technology University(MBSTU)SantoshTangail 1902Bangladesh Group of Biophotomatix SantoshTangail 1902Bagladesh Department of Software Enineering(SWE) Daffodil International UniversityShukrabadDhaka 1207Bangladesh

In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)*** nanowire is used as the active plasmonic *** into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon *** investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected *** of any polarization can be obtained by properly placing the metal *** maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μ*** a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter ***,the recommended PCF structure is useful for polarization device.

关键词： photonic crystal fiber (PCF) surface plasmon resonance (SPR) perfectly match layer polarization filter

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 KHAN 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

Growth performance of Avicennia officinalis L. and the effect of spacing on growth and yield of trees planted in the Western coastal belt of Bangladesh

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Journal of Forestry Research 2014年第4期25卷 835-838页

作者： md. Abdul Quddus Miah Sk. Ahiul Islam md. Ahsan Habib md. Golam Moula Plantation Trial Unit Division Bangladesh Forest Research Institute Rupatoli Barisal-8206 Bangladesh

A trial ofAvicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline （Patuakhali district） of Bangladesh since 1993 to assess growth perform- ance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and ana- lyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height （dbh） from 26.57-32.16 cm in plots of different spacings. The mean annual height increment ranged from 0,67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 ***＇*** in different treatments. Significantly greater diameter （32.16 cm） and wood volume （10.04 ***.a-1） were obtained with wider （2.13 m × 2.13 m） spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other .4. officinalis plantations raised by Forest Department （FD） on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height incre- ment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1,37 cm and wood volume from 1.55-5.73 m3·ha-1·a·-1. The growth performance of A. offindicated that the newly aecreted lands along the western shoreline may be suitable for raising Avicennia planta- tions for the enrichment of coastal vegetation.

关键词： growth Avicennia officinalis plantation spacing coastal belt

Macronutrient modulation of mRNA and microRNA function in animals:A review

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Animal Nutrition 2020年第3期6卷 258-268页

作者： md.Mahmodul hasan Sohel Department of Genetics Faculty of Veterinary MedicineErciyes University Genome and Stem Cell Centre Erciyes University

Dietary macronutrients have been regarded as a basic source of energy and amino acids that are necessary for the maintenance of cellular homeostasis,metabolic programming as well as protein *** to the emergence of"nutrigenomics",a unique discipline that combines nutritional and omics technologies to study the impacts of nutrition on genomics,it is increasingly evident that macro nutrients also have a significant role in the gene expression *** expression is a complex phenomenon controlled by several signaling pathways and could be influenced by a wide variety of environmental and physiological *** macronutrients are the most important environmental factor influencing the expression of both genes and microRNAs(miRNA).miRNA are tiny molecules of 18 to 22 nucleotides long that regulate the expression of ***,dietary macro nutrients can influence the expression of genes in both direct and indirect *** advancements in the state-of-the-art technologies regarding molecular genetics,such as next-generation sequencing,quantitative PCR array,and microarray,allowed us to investigate the occurrence of genome-wide changes in the expression of genes in relation to augmented or reduced dietary macronutrient intake,The purpose of this review is to accumulate the current knowledge focusing on macronutrient mediated changes in the gene *** review will discuss the impact of altered dietary carbohydrate,protein,and fat intake on the expression of coding genes and their *** addition,it will also summarize the regulation of miRNA,both cellular and extracellular miRNA,expression modulated by dietary macronutrients.

关键词： Nutrigenomics microRNA Circulating microRNA Carbohydrate Protein Fat

Development and validation of a simple UV spectrophotometric method for the determination of levofloxacin both in bulk and marketed dosage formulations

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Journal of Pharmaceutical Analysis 2012年第6期2卷 454-457页

作者： Mahfuza Maleque md. Raquibul hasan Farhad Hossen Sanjana Safi Department of Pharmacy School of Health Sciences State University of Bangladesh Dhaka Bangladesh Department of Clinical Pharmacy and Pharmacology Faculty of Pharmacy University of Dhaka Bangladesh

A rapid, specific and economic UV spectrophotometric method has been developed using a solvent composed of water：methanol：acetonitrile （9：0.5：0.5） to determine the levofloxacin content in bulk and pharmaceutical dosage formulations. At a pre-determined 2 of 292 nm, it was proved linear in the range of 1.0 12.0 μg/mL, and exhibited good correlation coefficient （R2=0.9998） and excellent mean recovery （99.0-100.07%）. This method was successfully applied to the determination of levofloxacin content in five marketed brands from Bangladesh and the results were in good agreement with the label claims. The method was validated statistically and by recovery studies for linearity, precision, repeatability, and reproducibility. The obtained results proved that the method can be employed for the routine analysis of levofloxacin in bulks as well as in the commercial formulations.

关键词： Fluoroquinolone Levofloxacin UV spectrophotometricmethod Validation

Estimation of the Stability of a River Island and Its Suitability for Installing Solar Based Power Plant in Bangladesh

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Journal of Geoscience and Environment Protection 2024年第11期12卷 51-72页

作者： md. Golam Muktadir md. Muhtasim Billah Anika Samm-A Farzana Rahman Nusrat Jahan Shimu Mahmudul hasan Intehum Taufique Aurnab mehedi hasan Peas Department of Environmental Science Bangladesh University of Professionals (BUP) Dhaka Bangladesh Department of Disaster Science and Climate Resilience University of Dhaka Dhaka Bangladesh Development & Production Division Bangladesh Oil Gas & Mineral Corporation (Petrobangla) Dhaka Bangladesh Department of Oceanography University of Dhaka Dhaka Bangladesh Bangladesh Space Research and Remote Sensing Organization (SPARRSO) Dhaka Bangladesh

Bangladesh, situated in tropical and subtropical regions, receives significant amount of solar energy, making it an ideal location for solar energy production. However, determining suitable sites in the country for solar based power plant establishment turns out to be a difficult task given its dense population. This study aims to the identification of such a potential site by assessing the stability of the Jamuna river Island to be proposed as a site for developing solar based power plant. The research concentrates on Fulchhari union of Gaibandha district, one of the three major islands in the Jamuna river, utilizing two GIS-based multi-criteria decision-making (MCDM) techniques. One is Digital Shoreline Analysis System (DSAS) for stability analysis, and another is Analytical Hierarchy Process (AHP) for suitability evaluation. For the stability analysis of the island, Landsat satellite imagery of 1990, 1995, 2000, 2005, 2010, 2015 and 2020 covering a long term of 30 years period were investigated. Based on average change rates, the bankline of the island was divided into 2 accretion zones in the south and south-eastern direction, and 8 erosion zones. Along with the bankline changes, climatological, geomorphological, and environmental factors have been adopted to modeling process for suitability analysis. The optimal locations for solar based power plants have been demonstrated by a suitability map, where high and standard potential area is about 60% of the area of Fulchhari union. Production may be enhanced up to 5 times more with the consideration of utilizing the moderate optimum zone.

关键词： Jamuna River Island GIS-DSAS GIS-AHP Stability Suitability

A monodisperse-aerosol generation system： Design, fabrication and performance

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Particuology 2017年第5期15卷 118-125页

作者： Amit md. Estiaque Arefin M.H. Masud Mohammad U.H. Joardder md. Shamim Akhter Department of Mechanical Engineering Rajshahi University of Engineering and Technology Rajshahi Bangladesh

Monodisperse aerosols are essential in many applications, such as filter testing, aerosol instrument calibration, and experiments for validating models. This paper describes the design principle, construction, and performance of a monodisperse-aerosol generation system that comprises an atomizer, virtual impactor, microcontroller-based isokinetic probe, wind tunnel, and velocity measurement device. The size distribution of the produced monodisperse aerosols was determined by an optical particle counter. The effects of atomizer characteristics, the rates of minor and major flow, and solution criteria were investigated. It was found that all these parameters affect the generation of monodisperse aerosol. Finally, the expected geometric standard deviation （〈1.25） of monodisperse aerosol particles was obtained with the most suitable atomizer for 10% oleic acid in ethyl alcohol solution with 5%-15% minor flow, where the ratio between the nozzle-to-probe distance and acceleration-nozzle-exit diameter was 0.66. The con- structed monodisperse-aerosol-generation system can be used for instrumental calibration and aerosol research.

关键词： Aerosol generation Monodisperse Design Sampling Counting