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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

Development and Performance Study of Controlled Atmosphere for Fresh Tomato

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World Journal of Engineering and Technology 2016年第2期4卷 168-175页

作者： md. Farid Ahmed md. Zahirul Islam md. Sazzat Hossain Sarker S. M. kamrul hasan Rakib Mizan Department of Food Engineering and Technology Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh Department of Food Processing and Preservation Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh

Development of a controlled atmosphere (CA) plant and shelf-life of fresh tomatoes at different storage conditions were studied in this research. The controlled chamber (4.5' × 4.5' × 4.5') with supplement of 1% L-ascorbic acid as antioxidant source was constructed using locally available materials. Fresh tomatoes were kept with wrapping by low density polyethylene under refrigerated and CA storage conditions. The maximum shelf-life of fresh tomato was 42 days under CA condition and followed by 35 days in refrigeration condition. Though initial cost of controlled atmosphere was high but it resulted in maximum shelf life of tomato. However, CA condition retained the physiological changes namely, color change, TSS, and weight loss of fresh tomatoes than that of stored in refrigerated condition. From nutritional point of view, it was concluded that developed CA plant could be used to extend the shelf-life of fresh tomatoes with minimum physico-chemical changes throughout the storage period.

关键词： Controlled Atmosphere Tomato Shelf-Life Storage Study Weight Loss

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

Research on the Development of Fibroin and Nano-Fiber from Silk Cocoons for Regenerated Tissue Engineering Applications by Electro-Spinning

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Advances in Nanoparticles 2024年第1期13卷 1-9页

作者： md.kamrul hasan Xinbo Ding School of Textile Science and Engineering International Silk Institute Zhejiang Sci-Tech University Hangzhou China

In this paper, the main goal is to prepare silk fibroin nano-fiber, which is used for regenerated tissue applications. Silk scaffold nano-fibers made by electro-spinning technology can be used in regenerated tissue applications. The purpose of the research is to prepare a silk-fibroin nano-fiber solution for potential applications in tissue engineering. Using a degumming process, pure silk fibroin protein is extracted from silk cocoons. The protein solution for fibroin is purified, and the protein content is determined. The precise chemical composition, exact temperature, time, voltage, distance, ratio, and humidity all have a huge impact on degumming, solubility, and electro-spinning nano-fibers. The SEM investigates the morphology of silk fibroin nano-fibres at different magnifications. It also reveals the surface condition, fiber orientation, and fiber thickness of the silk fibroin nano-fiber. The results show that regenerated silk fibroin and nano-fiber can be used in silk fibroin scaffolds for various tissue engineering applications.

关键词： Silk fibroin Scaffold electro-spinning nano-fiber Tissue Engineering

Preparation and Performance Study of PVA-Based Flexible Sensors

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Open Journal of Polymer Chemistry 2024年第1期14卷 19-40页

作者： md.kamrul hasan Xinbo Ding School of Textile Science and Engineering International Silk Institute Zhejiang Sci-Tech University Hangzhou China

Flexible sensors have great potential for monitoring human body motion signals. This paper presents a flexible sensor that uses zinc oxide (ZnO) to improve the mechanical properties and electrical conductivity of PVA hydrogel. The composite hydrogel has excellent conductive properties and high strain sensitivity, making it suitable for motion monitoring. The PVA/ZnO conductive hydrogel is tested on various body parts, showing effective feedback on movement changes and good electrical signal output effects for different motion degrees, confirming its feasibility in flexible sensors. The sensor exhibits good mechanical properties, electrical conductivity, and tensile strain sensing performance, making it a promising sensor material. It can accurately monitor wrist bending, finger deformation, bending, and large-scale joint movements due to its wide monitoring range and recoverable strain. The results show that the PVA/ZnO conductive hydrogel can provide effective feedback in flexible sensors, which is suitable for use in motion monitoring.

关键词： Polyvinyl Alcohol Zinc Oxide Zinc Oxide Nanorods Conductive Hydrogel Flexible Sensor

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

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