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Effect of Non-Equilibrium Condensation of Moist Air on Unsteady Behaviour of Shock Waves around a Circular Arc Blade

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Journal of Thermal Science 2007年第2期16卷 134-139页

作者： Shigeru MATSUO Kenbu TERAMOTO Miah md.ashraful alam Toshiaki SETOGUCHI Heuy Dong KIM Shen YU Department of Mechanical Engineering Saga University1Honjo-machiSaga-shiSaga 840-8502Japan Department of Mechanical Engineering Khulna University of Engineering & TechnologyKhulna-9203Bangladesh School of Mechanical Engineering Andong National University388Songchun-dongAndong 760749Korea Institute of Engineering Thermophysics Chinese Academy of SciencesP.O.Box 2706Beijing 100080China

The unsteady phenomena in the transonic flow around airfoils are observed in the flow field of fan, compressor blades and butterfly valves, and this often causes serious problems such as the aeroacoustic noise, the vibration. In the transonic or supersonic flow where vapour is contained in the main flow, the rapid expansion of the flow may give rise to a non-equilibrium condensation. However, the effect of non-equilibrium condensation on the transonic internal flows around the airfoil has not yet been clarified satisfactorily. In the present study, the effect of non-equilibrium condensation of moist air on the self-excited shock wave oscillation on a circular arc blade was investigated numerically. The results showed that in the case with non-equilibrium condensation, frequencies of the flow oscillation became smaller than those without the non-equilibrium condensation.

关键词： compressible flow transonic flow shock wave oscillation non-equilibrium condensation simulation

Turning Trash into Treasure: Developing an Intelligent Bin for Plastic Bottle Recycling

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Journal of Social Computing 2024年第1期5卷 1-14页

作者： Sirajam Munira Niloy Paul md ashraful alam md.Mahmudur Rahman M.Shamim Kaiser Institute of Information Technology Jahangirnagar UniversityDhaka 1342Bangladesh

Plastic pollution has emerged as a major global concern due to its enduring nature and limited recycling *** response to this critical challenge,this paper presents a novel approach utilizing a Detection-Based Reward System(DBRS)alongside an innovative business model to promote effective plastic waste management,reduce plastic waste accumulation in the nature,and uphold environmental *** the YOLOv5 algorithm for its exceptional accuracy,speed,and open-source availability,plastic bottle detection becomes a pivotal aspect of this *** seamlessly enroll in the system,triggering an automated detection process that computes reward points corresponding to their deposited plastic *** reward points are meticulously stored within a centralized *** its operational facets,this comprehensive system encompasses a robust business model,strategically poised to capture widespread engagement with waste disposal practices,thereby contributing to the realization of Sustainable Development Goals(SDGs)geared towards fostering a healthier ***,the DBRS attains cutting-edge performance in plastic bottle detection,boasting an impressive mean Average Precision(mAP)of 0.973,underscoring its efficacy in tackling plastic pollution.

关键词： smart environment reward system YOLOv5 deep learning business model

Upward Transition Probabilities B(E2)↑ Properties Study of Even-Even <sup>104-114</sup>Ru Nuclei

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World Journal of Nuclear Science and Technology 2020年第3期10卷 129-137页

作者： Tazul Islam Ruhol Amin md. ashraful alam Jobaidul Islam Department of Physics Mawlana Bhashani Science and Technology University Tangail Bangladesh

In this research work, the upward transition probabilities for the transition levels, 0+ → 2+, 2+ → 4+, 4+ → 6+ and 6+ → 8+ levels of even-even neutron rich 104-114Ru isotopes have been calculated by using the Global Best Fit (GBF) method. In addition, the associated parameters such as, Quadrupole moment and Deformation parameter of even-even 104-114Ru have been calculated. The dependency of these nuclear parameters shows the nuclear magic number tendency.

关键词： Upward Transition Probability Quadrupole Moment Deformation Parameter Global Best Fit (GBF) Method

Structure of Periodic Flows through a Channel with a Suddenly Expanded and Contracted Part

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Open Journal of Fluid Dynamics 2023年第S1期13卷 232-249页

作者： Takuya Masuda Toshio Tagawa Miah md. ashraful alam Yasutaka Hayamizu Department of Integrated Engineering National Institute of Technology Yonago College Tottori Japan Department of Aeronautics and Astronautics Tokyo Metropolitan University Tokyo Japan Department of Mechanical Engineering for Transportation Faculty of Engineering Osaka Sangyo University Osaka Japan

With respect to flows in a two-dimensional sudden expansion and contraction channel having a pair of cavities, numerical simulation was performed by imposing inlet/outlet boundary conditions giving a velocity distribution to the inlet. Periodic flows have been reproduced, which have a discrete spectrum about frequency. A fundamental wave occupies most part of the disturbance components, but higher harmonic waves are also included. The disturbance is excited by Kelvin-Helmholtz instability in a cavity section, where only the fundamental wave is generated. A wavenumber is regulated by a channel length under a periodic boundary condition, but there is no restriction in a main flow direction under the inlet/outlet boundary conditions, and therefore, some wavenumbers can occur. Therefore, an arbitrary frequency component of disturbance is a synthesized wave composed of various wave numbers. There are two kinds of components constituting this synthesized wave: a maximum of a velocity distribution is near a wall and in the center of the channel, which are called as wall mode and central mode in linear stability analysis of the plane Poiseuille flow. The synthesized wave composed of some modes shows a tendency to lower wavenumbers at the center of the channel.

关键词： Frequency Spectrum Harmonic Wave Number Phase Velocity Superposition Eigenfunction Profile

Advances in the light field displays based on integral imaging and holographic techniques(Invited Paper)

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Chinese Optics Letters 2014年第6期12卷 16-20页

作者： Nam Kim md. ashraful alam Le Thanh Bang Anh-Hoang Phan Mei-Lan Piao Munkh-Uchral Erdenebat School of Electrical and Computer Engineering Chungbuk National University410 Sungbong-ro Heungdeok-gu Cheongju Chungbuk 361-763 Korea

Light field displays comprise three-dimensional （3D） visual information presentation devices capable of providing realistic and full parallax autostereoscopic images. In this letter, the recent advances in the light field displays based on integral imaging （II） and holographic techniques are presented. Several advanced approaches to demonstrate the light field displays including viewing angle enhancement techniques of the II display, a fast hologram generation method using graphics processing unit （GPU） and multiple WRPs, and a holographic microscopy to display the living cells are reported. These methods improve some important constraints of the light field displays and add new features.

关键词： Advances in the light field displays based on integral imaging and holographic techniques II GPU

A Study on Fluidic Diode for Wave Energy Conversion-Effect of Bypass Geometry on the Turbine Performance

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Open Journal of Fluid Dynamics 2020年第3期10卷 270-278页

作者： Keito Matsumoto Manabu Takao Shinya Okuhara Miah md. ashraful alam Yoichi Kinoue National Institute of Technology Matsue College Matsue Japan Institute of Ocean Energy Saga University Saga Japan

A twin-impulse turbine for bi-directional flow has been developed for wave energy converter. However, the previous studies elucidated that the mean efficiency of the twin turbine is much lower than that of the impulse turbine for a unidirectional flow because a portion of airflow passes through the reverse flow turbine whose efficiency is very low. Therefore, a fluidic diode was adopted in the twin-impulse turbine in order to reduce the air flow through the reverse flow turbine. In this study, the rectification effect of the fluidic diode was investigated where a bypass is introduced into a blunt body. A computational fluid dynamics (CFD) analysis was conducted to investigate the effect of fluidic diodes on the turbine performance. In this analysis, RANS equations were used as the governing equations and the standard k-ε model was used as the turbulence model. The computational domain is composed of a circular tube and fluidic diode, and the domain meshed with an approximately 1.5 million mesh elements. As a result, it was found that the rectification effect of the fluidic diode is enhanced by installing a blunt body with a bypass hole of 5° taper angle.

关键词： Fluidic Diode Wave Energy Conversion Twin-Impulse Turbine CFD Analysis

Estimation of cytotoxic potency by brine shrimp lethality bioassay application of Clerodendrum infortunatum Linn.

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Journal of Coastal Life Medicine 2015年第8期 636-639页

作者： Talukdar Muhammad Waliullah Akter Mst Yeasmin ashraful md alam Wahedul md Islam Parvez Hassan Molecular Cellular Biology Laboratory Bioscience DepartmentGSSTShizuoka University836-OyaSuruga-kuShizuoka 422-8529Japan FIQC Laboratory Department of FisheriesMatshya BhabanRamnaDhaka-1000Bangladesh Institute of Biological Sciences University of RajshahiRajshahi-6205Bangladesh

Objective:To learn a scientific and systematic knowledge of anticancer,antimicrobial and pharmacological activities of natural products and estimate cytotoxic potency by using ethanol and chloroform extracts of root,leaf and stem of Clerodendrum infortunatum(Verbenaceae)due to its random use in customary and traditional medicine to cure common ailments such as intestinal disorder,diarrhea,tuberculosis and respiratory problems ***:The in vitro application was carried out with the bench-top bioassay method by using brine shrimp lethality ***:All of the crude extracts were found to be lethal and *** LC50 value of ethyl alcohol fraction of root was 20.845 mg/L compared to the standard drug tetracycline of 14.675 mg/L to brine shrimp nauplii,indicating that the extracts were biologically ***:The cytotoxic study of LC50 value showed that a good correlation with the antibiotic *** the comparative correlation error bars and percentage,we understood that ethyl alcohol fraction of root extract was very *** study serves as a basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.

关键词： Plant Ethnobotanical information Median lethal dose Cytotoxicity Artemia salina Standard deviation

Effect of Seeding Density on Mat-Type Seedling Quality for Mechanical Transplanting in Dry Season Rice

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Agricultural Sciences 2021年第11期12卷 1231-1243页

作者： Nilufar Yasmin Shaikh md. ashraful alam Mohammad Kamruzzaman md. Abdullah Al Mamun AKM Saiful Islam Biotechnology Division Bangladesh Rice Research Institute (BRRI) Gazipur Bangladesh Farm Machinery and Post-Harvest Technology Division Bangladesh Rice Research Institute (BRRI) Gazipur Bangladesh Agricultural Statistics Division Bangladesh Rice Research Institute (BRRI) Gazipur Bangladesh

Rice transplanting with a transplanter is a cost-effective process. Due to labor shortages during the peak time of rice transplanting, it is a promising technology in Bangladesh. However, the high-quality mat-type seedling is a prerequisite factor for mechanical transplanting. The experiments were conducted at three different locations (Gazipur, Tangail, and Rangpur) during the dry season (Boro)/2019-20 to determine the best seeding density for high-quality mat-type seedlings to be prepared for mechanical rice transplanters. The effects of seeding rate on seedling quality such as survival rate, seedling strength, stem thickness of newly released boro rice varieties BRRI dhan86, BRRI dhan89, and BRRI dhan92 were studied using four seeding rates (130, 140, 150, 160 g/tray). Results revealed that BRRI dhan92 showed quick seedling emergence compared to BRRI dhan89 and BRRI dhan86. Seedling mortality was found the lowest BRRI dhan92 while the highest in BRRI dhan86. 25 - 30 days old seedling was found suitable for mechanical transplanting in terms of seedling mortality. Seedling height increased with the increase in seed density. BRRI dhan92 showed the highest stem thickness followed by BRRI dhan89 and BRRI dhan86 with seed rate 150 - 160 g per tray. The suitable seeding rate (150 - 160 g/tray) for the studied varieties was found better for raising mat-type seedlings suitable for mechanical transplanting, which could coordinate the production of larger population growth and higher harvest index to achieve high grain yield.

关键词： Rice Seed Density Mortality Seedling Age Stem Thickness Seedling Strength

小麦条锈菌看家基因SNP引物的开发及多态性位点研究

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分子植物育种 2018年第5期16卷 1539-1544页

作者：李明菊 md.ashraful alam 李昊星程加省丁明亮云南省农业科学院农业环境资源研究所昆明650205 孟加拉国农业研究所小麦研究中心孟加拉迪纳杰布尔5200 华中农业大学生命科学技术学院武汉430070 云南省农业科学院粮食作物研究所昆明650205

利用NCBI数据库进行小麦条锈菌看家基因SNP引物开发,从NCBI搜索到15个基因的序列,利用Primer Premier 5.0软件设计了22对引物,利用其进行条锈菌DNA的PCR扩增、测序,并与标准序列比对,从而筛选出SNP引物。在候选基因中,柠檬酸盐合酶(Cs)... 详细信息

利用NCBI数据库进行小麦条锈菌看家基因SNP引物开发,从NCBI搜索到15个基因的序列,利用Primer Premier 5.0软件设计了22对引物,利用其进行条锈菌DNA的PCR扩增、测序,并与标准序列比对,从而筛选出SNP引物。在候选基因中,柠檬酸盐合酶(Cs)、热休克蛋白hsp90(Hsp)、泛素活化酶E1(Uba)及泛素结合酶E2(Ubc)4个基因的5对SNP引物表现多态性,能检测到条锈菌SNP位点依次为4、6~7、4和7个,均为系统发生信息位点,并摸索出优化的PCR反应体系及条件。利用开发的引物研究条锈菌群体结构,可揭示病原菌起源、进化、传播,为病害治理提供依据。

关键词：小麦条锈菌看家基因单核苷酸序列多态性引物开发