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Investigation on Lanthanum Fluoride as a Novel Cathode Buffer Material Layer for the Enhancement of Stability and Performance of Organic Solar Cell

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Optics and Photonics Journal 2014年第10期4卷 280-287页

作者： md. Shahinul Islam md. Golam Saklayen md. Ferdous Rahman Hartmut Baerwolff abu Bakar md. Ismail Department of Applied Physics & Electronic Engineering Rajshahi University Rajshahi Bangladesh Department of Electronics and Telecommunication Engineering Begum Rokeya University Rangpur Bangladesh Department of Analog & Optoelectronics Cologne University of Applied Sciences Cologne Germany

This article presents the investigation on very thin Lanthanum Fluoride (LaF3) layer as a new cathode buffer layer (CBL) for organic solar cell (OSC). OSCs were fabricated with poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) polymer blend at 1:1 ratio. Electron-beam evaporation at room temperature was used to deposit 3 and 5 nm thick LaF3 layer. A very smooth surface of LaF3 with an average roughness of 0.2 nm has been observed by the Atomic Force Microscope (AFM) that is expected to prevent diffusion of cathode metal ion through it and thereby enhance the lifetime and stability of OSC. Huge enhancement of JSC and VOC was also observed for 3 nm-thick LaF3 CBL. Several excellent features of the LaF3 layer such as, transporting electron through tunneling, blocking of holes to the cathode, minimizing recombination, protecting the photoactive polymer from ambient oxygen, and reducing degradation/oxidation of any low work function layer at the cathode interface, might have contributed to the performance enhancement of OSC. The experimental findings indicate the promise of LaF3 to be an excellent CBL material for OSC.

关键词： Organic Semiconductor Photoactive Polymer Organic Solar Cell Bulk Heterojunction Solar Cells Cathode Buffer Layer Lanthanum Fluoride Spin Coating E-Beam Evaporation

Determination of Array Gain of Single Hop to Achieve the Performance of a 2-Hop Wireless Link

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Journal of Computer and Communications 2018年第7期6卷 84-98页

作者： abu Sayed md. Mostafizur Rahaman Jesmin Akhter md. Rafsan Jani md. Imd.dul Islam Department of Computer Science and Engineering Jahangirnagar University Savar Dhaka Bangladesh Institute of Information Technology Jahangirnagar University Savar Dhaka Bangladesh

In adaptive beamforming system adaptive algorithm of digital filter is applied to update the weighting vector of the antenna elements to get antenna gain along the desired direction and attenuation along the jammer. The objective of the paper is to evaluate the threshold gain of the adaptive beam former along the line of sight (LOS) between the transmitter and the receiver (including jammer suppression) to make the single hop link comparable with 2-hop link. The single hop and 2-hop communication systems are compared in context of symbol error rate (SER) under fading condition theoretically and verified by simulation. Finally we evaluate the numerical value of threshold gain of adaptive beamformer of two antenna elements under Rayleigh and Nakagami-m fading conditions.

关键词： Array Antenna System BER Threshold Array Gain Side Lobe Canceller Path Loss

The Cyborg Entity in Gibson＇s Neuromancer： An Idealistic ＂Cyborg Manifesto？＂

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Journal of Literature and Art Studies 2015年第11期5卷 959-969页

作者： Sanyat Sattar abu Saleh md. Raft Jahangirnagar University Dhaka Bangladesh Daffodil International University Dhaka Bangladesh

The idea of Cyborg initiates the blurring of frontiers between traditional gender roles in the post-modem era, transforming itself into a politicized entity. William Gibson＇s Neuromancer as an early introducer of the Cyborg characters tries to dissolve the boundaries through his female characters by balancing the power quota with the help of the non-gendered entity of the Cyborg. According to Donna Haraway, there will be a dawn of new cyborg era causing a gender role reversal. The objective of this paper is to find whether such role reversal is at all possible.

关键词： cyborg postmodem fiction infotopia posthuman cyberfeminism cyborg manifesto

Intraspecific morphometric diversity of barramundi (Lates calcariferBloch, 1790) in the waters of southern Bangladesh

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Journal of Oceanology and Limnology 2019年第4期37卷 1393-1402页

作者： md.Reaz CHAKLADER Ashfaqun NAHAR md.abu HANIF Muhammad A. B. SIDDIK School of Molecular and Life Sciences Curtin University Bentley 6102 Australia Department of Marine Fisheries and Oceanography Patuakhali Science and Technology University Patuakhali 8602 Bangladesh Department of Fisheries Biology and Genetics Patuakhali Science and Technology University Patuakhali 8602 Bangladesh

A total of 160 barramundi's (Lates calcarifer Bloch, 1790) sampled from four rivers (Tentulia, Balaswar, Bakkhali, and Andarmanik) along the southern coastal region of Bangladesh were investigated in terms of morphometric characters to reveal the intraspecific variation. Twenty-five morphometric measurements were extracted using the conventional method and subjected to multivariate analyses (i.e., principal component analysis (PCA), discriminate function analysis (DFA), cluster analysis (CA)) to distinguish individuals from different rivers. The result demonstrated that twenty-two out of 25 measurements was statistically significant (Univariate ANOVA) among all four populations. PCA analysis of morphometric characters resulted in two principal components, PC I and PCⅡ which accounted for 79.25% and 4.28% of the total data variance. PC I-PC Ⅱ plot explained 83.53% of total variance differentiated the population of L. calcarifer into two groups. Discriminate analysis correctly classified about 88.1% of the examined fish into the four areas. The UPGMA dendrogram showed that Bakkhali populations were the most morphologically different populations in comparison to other populations, while Andarmanik and Balaswar populations were very close to each other. The strong morphometric variation between Bakkhali and Tentulia, Andarmanik and Balaswar was observed in the present study, suggested the evidence of the separate stock population of barramundi in these locations, which might require distinct stock management strategies for resource sustainability in the waters of southern Bangladesh. However, if these findings are supported by further molecular markers and geometric morphometry, this would be a strong indication of different stocks of this population in the four rivers of southern Bangladesh.

关键词： intraspecific diversity morphometric characters stock structure Lates calcarifer Bangladesh

Industrial IoT Based Condition Monitoring for Wind Energy Conversion System

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CSEE Journal of Power and Energy Systems 2021年第3期7卷 654-664页

作者： md.Liton Hossain Ahmed abu-Siada S.M.Muyeen md.Mubashwar Hasan Momtazur Rahman Department of Electrical and Computer Engineering Curtin UniversityPerthAustralia School of Science Engineering and ITFederation UniversityAustralia Edith Cowan University Australia

Wind energy has been identified as the second dominating source in the world renewable energy generation after *** and distribution of wind energy has brought technology revolution by developing the advanced wind energy conversion system(WECS)including multilevel inverters(MLIs).The conventional rectifier produces ripples in their output waveforms while the MLI suffers from voltage balancing issues across the DC-link *** paper proposes a simplified proportional integral(PI)-based space vector pulse width modulation(SVPWM)to minimize the output waveform ripples,resolve the voltage balancing issue and produce better-quality output *** experiences various types of faults particularly in the DC-link capacitor and switching devices of the power *** faults,if not detected and rectified at an early stage,may lead to catastrophic failures to the WECS and continuity of the power *** paper proposes a new algorithm embedded in the proposed PI-based SVPWM controller to identify the fault location in the power converter in real *** most wind power plants are located in remote areas or offshore,WECS condition monitoring needs to be developed over the internet of things(IoT)to ensure system *** this paper,an industrial IoT algorithm with an associated hardware prototype is proposed to monitor the condition of WECS in the real-time environment.

关键词： Asset management condition monitoring fault diagnosis industrial internet of things(IoT) wind energy conversion system

Influence of Thickness and Annealing Temperature on the Optical Properties of Spin-Coated Photoactive P3HT:PCBM Blend

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Optics and Photonics Journal 2013年第8期3卷 28-32页

作者： md. Shahinul Islam md. Earul Islam abu Bakar md. Ismail Hartmut Baerwolff Department of Analog & Optoelectronics Cologne University of Applied Sciences Cologne Germany Department of Applied Physics & Electronic Engineering Rajshahi University Rajshahi Bangladesh Department of Material Science & Engineering Rajshahi University Rajshahi Bangladesh

Influence of annealing temperature and thickness on the optical characteristics of the blend of poly (3-hexylthiophene) (P3HT) and Phenyl C61 butyric acid methylester (PCBM) layer has been investigated in this report. Photoactive polymer material (P3HT:PCBM) was deposited on indium tin oxide (ITO) substrate by spin-coating. The morphology of P3HT:PCBM composite layer was investigated by Atomic Force Microscope (AFM). The surface roughness was found to reduce after heat treatment. The absorption of the composite layer was found to increase with its number of layer (thickness). On the other hand, the photoluminescence (PL) quenching, which indicates efficient charge separation in the bulk heterojunction, was found higher for the thinner layer. Absorption was also found to increase with the annealing temperature. Therefore, to optimize the thickness of the P3HT:PCBM photoactive layer that will provide best absorption while providing efficient charge separation, annealing at optimized temperature might be an effective tool.

关键词： Organic Semiconductor Photoactive Polymer Bulk Heterojunction Solar Energy Materials

Wearable Antenna for Power Efficient On-Body and Off-Body Communications

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Journal of Electromagnetic Analysis and Applications 2014年第9期6卷 238-243页

作者： Mohammad Monirujjaman Khan md. Azizur Rahman md. abu Talha Tarannum Mithila 1Electronics and Telecommunication Engineering University of Liberal Arts Bangladesh Dhaka Bangladesh 2School of Electronic Engineering and Computer Science Queen Mary University of London London UK Department of Computer & Information Technology London School of Technology London UK Electronics and Telecommunication Engineering University of Liberal Arts Bangladesh Dhaka Bangladesh

A novel dual-band and diverse radiation pattern antenna is proposed for power efficient on-body and off-body communications intended for various applications in healthcare and sport monitoring. The antenna is dual band at 2.45 GHz (ISM band) with omnidirectional radiation pattern over the body surface to communicate power efficiently with other co-located body worn devices and at 1.9 GHz (PCS band), it has directive radiation pattern towards off the body to communicate from on-body device to off-body devices. The free space and on-body performances of the antenna are investigated by both simulation and experiment. The antenna shows very good on-body radiation efficiency of 58% at 2.45 GHz and 61% at 1.9 GHz. Good on-body gain is noticed at both frequency bands. Results show that the gain of the proposed antenna increases by 4.7% at 2.45 GHz and 3.2% at 1.9 GHz when placed on the body.

关键词： Dual Band Diverse Radiation Pattern Power Efficient On-Body Communications Power Efficient Off-Body Communications Body-Centric Wireless Communications

Spatiotemporal patterns and trends of community transmission of the pandemic COVID-19 in South Asia: Bangladesh as a case study

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Biosafety and Health 2021年第1期3卷 39-49页

作者： Ariful Islam abu sayeed Kaisar Rahman Jinnat Ferdous Shahanaj Shano Shusmita Dutta Choudhury Mohammad Mahmudul Hassan EcoHealth Alliance New York NY 10001-2320USA Centre for Integrative Ecology School of Life and Environmental ScienceDeakin UniversityVictoria 3216Australia Department of Medicine Jhenaidah Government Veterinary CollegeJhenaidah 7300Bangladesh Faculty of Veterinary Medicine Chattogram Veterinary and Animal Sciences UniversityChattogram 4225Bangladesh Institute of Epidemiology Disease Control and Research(IEDCR)Dhaka 1212Bangladesh

South Asian(SA)countries have been fighting with the pandemic novel coronavirus disease 2019(COVID-19)since January ***,the country-specific descriptive study has been ***,as transboundary infection,the border sharing,shared cultural and behavioral practice,effects on the temporal and spatial distribution of COVID-19 in SA is still ***,this study has been revealed the spatial hotspot along with descriptive output on different parameters of COVID-19 *** extracted data from theWHO and the worldometer database from the onset of the outbreak up to 15 May,*** has the highest case fatality rate(CFR,9.22%),whereas Oceania has the highest(91.15%)recovery rate from *** SA countries,India has the highest number of cases(85,790),followed by Pakistan(38,799)and Bangladesh(20,065).However,the number of tests conducted was minimum in this region in comparison with other *** highest CFR was recorded in India(3.21%)among SA countries,whereas Nepal and Bhutan had no death record due to COVID-19 so *** recovery rate varies from 4.75%in the Maldives to 51.02%in Sri *** Bangladesh,community transmission has been recorded,and the highest number of cases were detected in Dhaka,followed by Narayanganj and *** detected Dhaka and its surrounding six districts,namely Gazipur,Narsingdi,Narayanganj,Munshiganj,Manikganj,and Shariatpur,as the 99%confidence-based hotspot where Faridpur and Madaripur district as the 95%confidence-based spatial hotspots of COVID-19 in ***,we did not find any cold spots in *** identified three hotspots and three cold spots at different confidence levels in *** from this study suggested the“Test,Trace,and Isolation”approach for earlier detection of infection to prevent further community transmission of COVID-19.

关键词： Case fatality rate Dhaka South Asia Risk Community transmission Bangladesh

Anaortic Off-Pump Complete Arterial Revascularization Using Composite LIMA RIMA Y Sequential 5 Grafts in a Patient with Triple Vessel Disease Performed in a Low Resource Country: A Case Report

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World Journal of Cardiovascular Surgery 2021年第12期11卷 125-132页

作者： Asraful Hoque Romena Rahman abu Shadat Mohammad Saem Khan md. Abdullah Yusuf Muhammad Asif Ahsan Chowdhury imran Ahmed Wahida Salam md. Monzur Hossain Tanvir Hossain Department of Cardiac Surgery National Institute of Cardiovascular Diseases Dhaka Bangladesh Department of Microbiology National Institute of Neurosciences and Hospital Dhaka Bangladesh

The use of bilateral internal thoracic arteries to treat coronary artery disease is very less despite of improved long-term survival. In this case report, a patient presented with TVD has been managed with anaortic off-pump complete arterial revascularization (OPCABG) by using composite LIMA RIMA Y Sequential 5 grafts to achieve complete arterial revascularization successfully. This type of operative procedure is technically difficult in a resource poor country like Bangladesh. However, this has been done by a group of young cardiac surgeon. During follow up, the patient is in a good condition.

关键词： Anaortic Off-Pump Complete Arterial Revascularization Composite LIMA RIMA Y Sequential 5 Grafts Triple Vessel Disease Low Resource Country