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Frontiers of Optoelectronics 2017年第4期10卷 370-377页

作者： Sakhawat HUSSAIN Tasnim ZERIN md. ashik khan Department of Electrical and Electronic Engineering University of Dhaka Dhaka-1000 Bangladesh

This study considered the design of an efficient, high brightness polar InGaN/GaN light emitting diode （LED） structure with A1GaN capping layer for green light emission. The deposition of high In （〉 15%） composition within InGaN quantum well （QW） has limitations when providing intense green light. To design an effective model for a highly efficient InGaN green LEDs, this study considered the compositions of indium and aluminum for InxGal xN QW and AlyGal yN cap layers, along with different layer thicknesses of well, barrier and cap. These structural properties significantly affect different properties. For example, these properties affect electric fields of layers, polarization, overall elastic stress energy and lattice parameter of the structure, emission wavelength, and intensity of the emitted light. Three models with different composition and layer thicknesses are simulated and analyzed to obtain green light with in-plane equilibrium lattice parameter close to GaN （3.189 A ） with the highest oscillator strength values. A structure model is obtained with an oscillator strength value of 1.18 × 10-1 and least in-plane equilibrium lattice constant of 3.218 A. This emitter can emit at a wavelength of 540 nm, which is the expected design for the fabrication of highly efficient, bright green LEDs.

关键词： green light emitting diode (LED) latticeparameter oscillator strength InGaN quantum well (QW),A1GaN capping layer

Status and prospects for symmetric organic redox flow batteries

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Journal of Energy Chemistry 2025年第1期100卷 125-143页

作者： md.Al Raihan C.Adam Dyker Department of Chemistry University of New Brunswick

As environmental concerns from fossil fuel consumption intensify, large-scale energy storage becomes imperative for the integration of renewable sources like wind, hydro, and solar with the electrical *** flow batteries, particularly those employing organic molecules, are positioned as a key technology for this purpose. This review explores the growing field of symmetric organic redox flow batteries(ORFBs) within this context. Unlike traditional asymmetric designs based on unique active materials for each electrode, symmetric ORFBs involve a single bipolar species for both electrodes. This review highlights the benefits of a symmetric design, and categorizes five distinct classes of organic bipolar molecules used in both aqueous and non-aqueous solvents. By providing a comprehensive overview of their cell cycling and performance characteristics, the strengths and weaknesses of the diverse categories of bipolar molecules are highlighted for both solvent systems, as are opportunities for future development. This should guide new research directions and advance the development of practical symmetric ORFBs.

关键词： Redox flow battery Symmetric battery Organic battery Aqueous electrolyte Non-aqueous electrolyte

Regeneration mechanisms and therapeutic strategies for neuromuscular junctions in aging and diseases

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Neural Regeneration Research 2025年第1期20卷 193-194页

作者： Masashi Fujitani Abu md.Mamun Tarif Yoshinori Otani Department of Anatomy and Neuroscience Faculty of MedicineShimane UniversityShimaneJapan

The neuromuscular junction(NMJ)is an essential synaptic structure composed of motor neurons,skeletal muscles,and glial cells that orchestrate the critical process of muscle contraction(Li et al.,2018).The typical NMJ structure is classically described as having a“pretzel-like”shape in mice(Figure 1),whereas human NMJs have a smaller,fragmented structure throughout *** NMJs exhibit smaller or fragmented endplates,partial denervation,reduced numbers of synaptic vesicles,abnormal presynaptic mitochondria,and dysfunctional perisynaptic Schwann cells(Alhindi et al.,2022).

关键词： aging structure Figure

Steel Surface Defect Detection Using Learnable Memory Vision Transformer

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Computers, Materials & Continua 2025年第1期82卷 499-520页

作者： Syed Tasnimul Karim Ayon Farhan md.Siraj Jia Uddin Department of Computer Science and Engineering BRAC UniversityDhaka1212Bangladesh Department of AI and Big Data Endicott CollegeWoosong UniversityDaejeon34606Republic of Korea

This study investigates the application of Learnable Memory Vision Transformers(LMViT)for detecting metal surface flaws,comparing their performance with traditional CNNs,specifically ResNet18 and ResNet50,as well as other transformer-based models including Token to Token ViT,ViT withoutmemory,and Parallel *** awidely-used steel surface defect dataset,the research applies data augmentation and t-distributed stochastic neighbor embedding(t-SNE)to enhance feature extraction and *** techniques mitigated overfitting,stabilized training,and improved generalization *** LMViT model achieved a test accuracy of 97.22%,significantly outperforming ResNet18(88.89%)and ResNet50(88.90%),aswell as the Token to TokenViT(88.46%),ViT without memory(87.18),and Parallel ViT(91.03%).Furthermore,LMViT exhibited superior training and validation performance,attaining a validation accuracy of 98.2%compared to 91.0%for ResNet 18,96.0%for ResNet50,and 89.12%,87.51%,and 91.21%for Token to Token ViT,ViT without memory,and Parallel ViT,*** findings highlight the LMViT’s ability to capture long-range dependencies in images,an areawhere CNNs struggle due to their reliance on local receptive fields and hierarchical feature *** additional transformer-based models also demonstrate improved performance in capturing complex features over CNNs,with LMViT excelling particularly at detecting subtle and complex defects,which is critical for maintaining product quality and operational efficiency in industrial *** instance,the LMViT model successfully identified fine scratches and minor surface irregularities that CNNs often *** study not only demonstrates LMViT’s potential for real-world defect detection but also underscores the promise of other transformer-based architectures like Token to Token ViT,ViT without memory,and Parallel ViT in industrial scenarios where complex spatial relationships are *** research m

关键词： Learnable Memory Vision Transformer(LMViT) Convolutional Neural Networks(CNN) metal surface defect detection deep learning,computer vision image classification learnable memory gradient clipping label smoothing t-SNE visualization

Quasi-inverse Pendulum Model of 12 DoF Bipedal Walking

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International Journal of Automation and computing 2017年第2期14卷 179-190页

作者： M. Akhtaruzzaman Amir A. Shafie md. Raisuddin khan Department of Mechatronics Engineering Kulliyyah of Engineering International Islamic University Malaysia Kuala Lumpur 53100 Malaysia

This paper presents modeling of a 12-degree of freedom （DoF） bipedal robot, focusing on the lower limbs of the system, and trajectory design for walking on straight path. Gait trajectories are designed by modeling of center of mass （CoM） trajectory and swing foot ankle trajectory based on stance foot ankle. The dynamic equations of motion of the bipedal robot are derived by considering the system as a quasi inverted pendulmn （QIP） model. The direction and acceleration of CoM movement of the QIP model is determined by the position of CoM relative to the centre of pressure （COP）. To determine heel-contact and toe-off, two custom designed switches are attached with heel and toe positions of each foot. Four force sensitive resistor （FSR） sensors are also placed at the plantar surface to measure pressure that is induced on each foot while walking which leads to the calculation of CoP trajectory. The paper also describes forward kinematic （FIK） and inverse kinematic （IK） investigations of the biped model where Denavit-Hartenberg （D-H） representation and Geometric-Trigonometric （G-T） formulation approach are applied. Experiments are carried out to ensure the reliability of the proposed model where the links of the bipedal system follow the best possible trajectories while walking on straight path.

关键词： Humanoid robot quasi-inverse pendulum gait trajectory planning Anthropoid.

Options and Opportunities for Energy Management in Malaysian Grid Systems-Putrajaya as a Case Study

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Journal of Electronic Science and Technology 2018年第4期16卷 316-324页

作者： Aravind CV Umashankar Subramaniam md.Shahrukh Adnan khan md. Ibrahim Ibne Alam School of Engineering Taylor’s University Subang Jaya 47500 Malaysia Department of Energy and Power Electronics VIT University Vellore 632014 India University of Asia Pacific Dhaka 1205 Bangladesh

This paper presents an opportunity for energy management with an integrated photovoltaic and wind farm for the energy and economic aspects of the commercial area located in Putrajaya. The energy economy accession conforming to the wind speed, temperature, solar irradiation, and energy consumption on a daily basis is taken into consideration. Design analysis is done through the industry standard numerical tool. From the result analysis, the recommended ratio of renewable share minimizing stress to the electric grid is proposed. According to the solutions obtained from the numerical design tool, photovoltaic is recommended to be more energy efficient and economically viable in comparison of the fully crowded wind farm. From the proposed solutions, the photovoltaic is able to provide 51% of the energy consumed and it costs RM 0.365 per kW/h.

关键词： Cost grid Homer Pro photovoltaic park wind turbine farm

MOVPE Growth of In_xGa_(1-x)N(x～0.4) and Fabrication of Homo-junction Solar Cells

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Journal of Materials Science & Technology 2013年第2期29卷 128-136页

作者： md. Rafiqul Islam md. Rejvi Kaysir md. Jahirul Islam A. Hashimoto A. Yamamoto Department of Electrical and Electronic Engineering KUETKhulna 9203 Bangladesh Graduate School of Engineering University of Fukui 3-9-1 BunkyoFukui 910-8507 Japan

The metal organic vapor phase epitaxy （MOVPE） growth of indium gallium nitride （InGaN） has been discussed in detail towards the fabrication of solar cell. The InGaN film with In contents up to 0.4 are successfully grown by controlling the fundamental growth parameters such as the precursor gas flow rates, temperature etc. The formation of metallic In originates from the higher value （0.74） of trimethylindium/ （trimethylindium ＋ triethylgallium）（TMI/（TMI ＋ TEG）） molar ratio with low （4100） V/lll weight molar ratio while the lower value （0.2） of TMI/（TMI ＋ TEG） causes the phase separation. It is also necessary to control the growth rate and epitaxial film thickness to suppress the phase separation in the material. The crystalline quality of grown films is studied and it is found to be markedly deteriorated with increasing In content. The lattice parameters as well as the thermal expansion coefficient mismatch between GaN template and InGaN epi-layer are primarily considered as the reasons to deteriorate the film quality for higher In content. By using Ino.16Ga0.84N films, an n＋-p homo-junction structure is fabricated on 0.65 μm GaN template. For such a device, the response to the light illumination （AM 1.5） is observed with an open circuit voltage of 1.4 V and the short circuit current density of 0.25 mA/cm2. To improve the performance as well as increase solar photon capturing, the device is further fabricated on thick GaN template with higher In content. The In0.25Ga0.75N n＋-p junction solar cell is found better performance with an open circuit voltage of 1.5 V and the short circuit current density of 0.5 mA/cm2. This is the InGaN p-n homo-junction solar cell with the highest In content ever reported by MOVPE.

关键词： InGaN Metal organic vapor phase epitaxy (MOVPE) Growth Film quality Doping p-n junction

Morphological and Genetical Variability among Rhizoctonia solani Isolates Causing Sheath Blight Disease of Rice

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Rice science 2016年第1期23卷 42-50页

作者： Zakiah Rahman MONI md.Ansar ALI md.Shahidul ALAM md.Asif RAHMAN md.Rejwan BHUIYAN md.Salim MIAN khandakar md.IFTEKHARUDDAULA md.Abdul LATIF Mohammad ashik Iqbal khan Plant Breeding Division Bangladesh Rice Research Institute Director Research Bangladesh Rice Research Institute Department of Botany Rajshahi University Department of Genetics and Plant Breeding Bangabandhu Sheikh Mujibur Rahman Agricultural University Plant Pathology Division Bangladesh Rice Research Institute

Eighteen isolates of Rhizoctonia solani collected from infected rice plants in four different locations of Bangladesh were studied by using morphological characters and molecular markers. Anastomosis study with a reference isolate confirmed that all the isolates belonged to R. solani. Significant variation was observed in sclerotial size, shape and distribution. Un-weighted pair group method with arithmetic mean dendrogram constructed based on the Gower＇s general similarity coefficient showed that these isolates were grouped into four clusters at the 0.68 similarity coefficent according to morphological characters. Cluster I was a major cluster consisting of 13 isolates, while clusters Ⅱ to Ⅳ consisted of 1 or 2 isolates. Analyses by variable number of tandem repeat and amplified fragment length polymorphism markers showed that the isolates were grouped into five and three clusters at a similarity coefficient of 0.64 and 0.69, respectively. Although most of the variability was found between isolates from different regions as expected, significant variation was observed within the isolates collected from similar agro-ecological regions. Our results suggest the presence of different races of R. solani within the same local geographic regions.

关键词： rice Rhizoctonia solani fungal variability molecular marker morphological character

Biogas generation from kitchen and vegetable waste in replacement of traditional method and its future forecasting by using ARIMA model

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Waste Disposal and Sustainable Energy 2021年第2期3卷 165-175页

作者： Pranta Roy md.ashik Ahmed md.Hakimuzzaman Shah Department of Civil Engineering Dhaka International UniversityDhakaBangladesh Ingram School of Engineering Texas State UniversitySan MarcosTX 78666USA Department of Civil Engineering Khulna University of Engineering and TechnologyKhulnaBangladesh

Nowadays,traditional energy resources are going into a vulnerable condition *** that note biogas is an emerging subsidiary ***,cow-dung is used as a basic raw material to produce *** this study,various forms of putrescible waste like kitchen and vegetable waste were giving emphasis to produce biogas as a replacement of cow dung as well as good management of putrescible waste.2000 kg of kitchen and 1050 kg of vegetable waste were used in a biogas plant continuously for 15 days with a waste/water ratio of 1:*** 133.33 kg of kitchen and 70 kg of vegetable waste generated 2.27 kg and 1.17 kg of biogas per day ***,the average time of burning of biogas for kitchen and vegetable waste was 7.92 *** 4.08 *** day in some *** benefit-cost ratio was greater than 1 for both cases that’s why it can be reckoned as an efficacious *** Integrated Moving Average(ARIMA)model was performed to forecast the amount of biogas generation for kitchen and vegetable waste for the next 10 *** residual sum of square(RSS)value of the ARIMA model for kitchen and vegetable waste was 0.028437 and 0.139524 respectively which indicates ***,predictions of the amount of biogas generation are plotted with a 95%confidence *** forecast indicates that biogas from kitchen waste is more proficient than vegetable waste for the next 10 ***,this putrescible waste can be a prominent raw material for next-gen biogas production.

关键词： Biogas Putrescible waste Benefit-cost analysis Waste management Forecasting

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： md.Ahasan Habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-Hun Jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Potassium hydroxide