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Chemical sensing through photonic crystal fiber:sulfuric acid detection

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Frontiers of Optoelectronics 2019年第4期12卷 372-381页

作者： Etu PODDER md.Belial HOSSAIN Rayhan habib JIBON Abdullah Al-Mamun BULBUL Himadri Shekhar MONDAL Electronics and Communication Engineering Discipline Khulna UniversityKhulna-9208Bangladesh Department of Electronics and Telecommunication Engineering(ETE) Bangabandhu Sheikh Mujibur Rahman Science and Technology UniversityGopalganjBangladesh

A photonic crystal fiber(PCF)for sensing of sulfuric acid is designed and analyzed using Comsol *** analyze the sensor performance,0%,10%,20%,30%,40%H2SO4 solution is placed into the fiber separately and then relative sensitivity,confinement loss,birefringence,effective area *** investigated for each solution over wavelength ranging from 0.8 to 1.8μ*** sensor structure affords moderately high relative sensitivity and around 63.4%sensitivity is achieved for the highest concentration of H2SO4 at the wavelength 1.5|im inxpolarization *** PCF model also shows zero confinement loss for all solutions of H2SO4 over wavelength ranging from 1 to 1.35μm and later on approximately 1.422×10^-17 dB/km confinement loss is found for the highest concentration of H2SO4 at 1.5|im ***,higher birefringence is attained when the concentration of sulfuric acid is lower and it is achieved 7.5×10^-4 at 1.5μm ***,higher sensing area is achieved at high concentration of sulfuric acid.

关键词： refractive index confinement loss birefri gence relative sensitivity

Quantum-Edge Cloud Computing for IoT: Bridging the Gap between Cloud, Edge, and Quantum Technologies

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Advances in Internet of Things 2024年第4期14卷 99-120页

作者： Shahanaz Akter md. Khairul Islam Bhuiyan md. Bahauddin Badhon habib md. Hasan Fatema Akter Mohammad Nahid Ul Islam Department of Accounting and Finance Southern Utah University Cedar City USA Inventive Apps Ltd. New York USA School of Business and Technology Emporia State University Emporia USA

The rapid expansion of the Internet of Things (IoT) has driven the need for advanced computational frameworks capable of handling the complex data processing and security challenges that modern IoT applications demand. However, traditional cloud computing frameworks face significant latency, scalability, and security issues. Quantum-Edge Cloud Computing (QECC) offers an innovative solution by integrating the computational power of quantum computing with the low-latency advantages of edge computing and the scalability of cloud computing resources. This study is grounded in an extensive literature review, performance improvements, and metrics data from Bangladesh, focusing on smart city infrastructure, healthcare monitoring, and the industrial IoT sector. The discussion covers vital elements, including integrating quantum cryptography to enhance data security, the critical role of edge computing in reducing response times, and cloud computing’s ability to support large-scale IoT networks with its extensive resources. Through case studies such as the application of quantum sensors in autonomous vehicles, the practical impact of QECC is demonstrated. Additionally, the paper outlines future research opportunities, including developing quantum-resistant encryption techniques and optimizing quantum algorithms for edge computing. The convergence of these technologies in QECC has the potential to overcome the current limitations of IoT frameworks, setting a new standard for future IoT applications.

关键词： Quantum-Edge Cloud Computing (QECC) Internet of Things (IoT) Low Latency Quantum Computing (QC) Scalable Cloud Services

Measurement and correlation of solubility of diosmin in four pure solvents and β-cyclodextrin solution at 298.15K to 333.15K

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Chinese Journal of Chemical Engineering 2015年第5期23卷 812-815页

作者： md Khalid Anwer Faiyaz Shakeel Department of Pharmaceutics College of Pharmacy Salman Bin Abdulaziz University Center of Excellence in Biotechnology Research King Saud University Department of Pharmaceutics College of Pharmacy King Saud University

The aim of present study was to measure and correlate the solubility of poorly water-soluble flavonoid diosmin in water, ethanol, isopropyl alcohol （IPA）, polyethylene glycol-400 （PEG-400） and β-cyclodextrin （β-CD） aqueous solution （0.02 mol·L^-1 ）. The solubility of diosmio was measured using the shake flask method from （298.15 to 333.15） K at atmospheric pressure. The experimental solubilities of diosmin were regressed by the modified Apelblat model with a relative deviation in the range of 0.048% to 5.940%. The correlation coefficients were observed in the range of 0.9957 to 0.9995. The solubility of diosmin was found to be increased with temperature in all sample matrices investigated. The mole fraction solubility of diosmin was found to be higher in 5-CD aqueous solution and PEG-400 as compared to water, ethanol and IPA. Based on solubility data of present study, diosmin was considered as practically insoluble in water, insoluble in ethanol ＆ IPA and soluble in PEG- 400 and β-CD aqueous solution.

关键词： Apelblat model Cyclodextrin Diosmin Solubility Thermodynamics

Improved voltage tracking of autonomous microgrid technology using a combined resonant controller with lead-lag compensator adopting negative imaginary theorem

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Protection and Control of Modern Power Systems 2022年第1期7卷 149-164页

作者： md.Yah-Ya Ul Haque md.Rashidul Islam Tanvir Ahmed md.Rafiqul Islam Sheikh Department of Electrical and Electronic Engineering Varendra UniversityRajshahi 6204Bangladesh Department of Electrical and Electronic Engineering Rajshahi University of Engineering&TechnologyRajshahi 6204Bangladesh

Growing application of distributed generation units at remote places has led to the evolution of microgrid(MG)*** an MG system functions independently,i.e.,in autonomous mode,unpredictable loads and uncertainties emerge throughout the *** obtain stable and flexible operation of an autonomous MG,a rigid control mechanism is *** this paper,a robust high-performance controller is introduced to improve the performance of voltage tracking of an MG system and to eliminate stability problems.A combination of a resonant controller and a lead-lag compensator in a positive position feedback path is designed,one which obeys the negative imaginary(NI)theorem,for both single-phase and three-phase autonomous MG *** controller has excellent tracking *** is investigated through considering various uncertainties with different load *** feasibility and effectiveness of the controller are also determined with a comparative analysis with some well-known controllers,such as linear quadratic regulator,model predictive and NI approached resonant *** confirms the superi-ority of the designed controller.

关键词： Negative imaginary theorem Resonant controller Lead-lag compensator Autonomous microgrid Voltage tracking

Dosimetric Characteristics of 6 MV Medical Linac at BAEC

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International Journal of Medical Physics, Clinical Engineering and Radiation Oncology 2021年第1期10卷 38-46页

作者： Sudeb Kumar Roy Pretam Kumar Das Rajada Khatun md. Ashikur Rahman Shirin Akter Tushar Kumar Mohammad Monjur ahasan Department of Physics Pabna University of Science and Technology Pabna Bangladesh Medical Physics Division Atomic Energy Centre Dhaka Bangladesh Institutes of Nuclear Medical Physics Atomic Energy Research Establishment Savar Dhaka Bangladesh

Dosimetric characteristic is one of the essential parameters of a medical linear accelerator (LINAC), which must be obtained before clinical use. The dosimetric characteristics for 6 MV photon beam were measured and compared with the corresponding published data. The study was done using a Varian linear accelerator (Model Clinac-iX) at the Institute of Nuclear Medical Physics (INMP), AERE, Savar, Dhaka, under the Bangladesh Atomic Energy Commission (BAEC). The data is taken for 10 field sizes (2 × 2, 3 × 3, 5 × 5, 7 × 7, 10 × 10, 15 × 15, 20 × 20, 25 × 25, 30 × 30 and 40 × 40 cm2) at same conditions. The measured Percent Depth Dose (PDD) curves were obtained for 6 MV photon beams with the field as mentioned above and compared with the calculated PDD curves. The measured depth dose (Dmax) for reference field size (FS) 10 × 10 cm2 is 15.99 mm, and the PDD at 10 cm depth (D10) is 66.87% for 6 MV photon energies that are found to be compatible with the published report BJR supplement 25. The measured PDD curves for photon energies show a good agreement with the standard PDD curves. The photon beam dosimetry data found in the current study are compatible and all the tolerances are within the clinically acceptable tolerance limit.

关键词： Linac Machines 3D Water Phantom Ionization Chamber Electrometer

Solution processed high performance perovskite quantum dots/ZnO phototransistors

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Nano Research 2022年第4期15卷 3660-3666页

作者： md Mehedi Hasan Eric Moyen Jewel Kumer Saha md Mobaidul Islam Arqum Ali Jin Jang Advanced Display Research Center(ADRC) Department of Information DisplayKyung Hee University26Kyungheedae-roDongdaemun-guSeoul 02447Republic of Korea

Phototransistors that can detect visible light have been fabricated using solution processed zinc oxide channel/zirconium oxide gate insulator thin film transistors(TFTs)and room temperature synthesized perovskite quantum dots(PeQDs)as active *** ZnO thin film transistors did not show a photocurrent under visible light ***,ZnO TFTs decorated with PeQDs exhibited enhanced photocurrent upon exposure to visible *** device had a responsivity of 567 A/W(617 A/W),a high detectivity of 6.59×10^(13)Jones(1.85×10^(14)J)and a high sensitivity of 10^(7)(10^(8))under green(blue)light at a low drain voltage of 0.1 *** high photo-responsivity and detectivity under green light resulted from the combination of short ligands in the QDs films and the high mobility of the spray coated ZnO *** results are relevant for the development of low cost and low energy consumption phototransistors working in the visible range.

关键词： ZnO thin film transistors perovskite quantum dots photo-detectors photo-transistors

Investigation of phase-change materials for interior temperature regulation in public transport

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Clean Energy 2022年第1期6卷 178-192页

作者： md Nahidul Islam md Nahid Hossain Dewan HasanAhmed Department of Mechanical and Production Engineering Ahsanullah University of Science and Technology141-142 Love RoadTejgaon Industrial AreaDhakaBangladesh

Regulating the indoor temperature of public transport on hot sunny days is a prime concern,as both the external and internal heat sources play an active role in heat *** studies have been carried out on a bus model using sodium sulphate decahydrate as a phase-change material(PCM)that is placed in between the ceiling and the *** are conducted on a sunny day and also for different cases of external(300-W surface heater)and internal(25-W light bulb)heat *** results show that PCM,in the presence of an external heat source,can help to keep the indoor temperature lower and delay the time period for increasing the temperature by absorbing heat during the phase *** the other hand,the presence of the internal heat source contributes to a detrimental effect on the indoor temperature,which gradually increases with the elapse of *** the combination of the external and internal heat sources,it is found that the internal heat source plays a dominating factor to raise the indoor *** is revealed from the experimental results that a 12.7-mm single layer and a single PCM are not enough to counter the internal heat of 25 W unless the thickness of the PCM layer is increased to delay the increase in the indoor *** additional PCM layer with a lower melting temperature could be placed at the inner portion of the ceiling to have effective thermal-energy storage by absorbing the substantial heat gain from the internal heat sources.

关键词： latent heat sodium sulphate decahydrate phase-change material transportation thermal-energy storage

quantum gases power law potential grand potential condensation hierarchy

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Communications in Theoretical Physics 2016年第2期65卷 169-176页

作者： Mir Mehedi Faruk md.Sazzad Hossain md.Muktadir Rahman Department of Theoretical Physics University of Dhaka Dhaka-lO00 Bangladesh Theoretical Physics Blackett Laboratory Imperial College London SW7 2AZ United Kingdom Department of Nuclear Engineering University of Dhaka Dhaka-1000 Bangladesh

The changes in characteristics of Bose condensation of ideal Bose gas due to an external generic power law potential U =∑~d_（i=1）ci｜xi/ai｜~（ni） are studied carefully. Detailed calculation of Kim et al.（J. Phys. Condens. Matter 11（1999） 10269） yielded the hierarchy of condensation transitions with changing fractional dimensionality. In this manuscript, some theorems regarding specific heat at constant volume CV are presented. Careful examination of these theorems reveal the existence of hidden hierarchy of the condensation transition in trapped systems as well.

关键词： Investigation of Bose Condensation in Ideal Bose Gas Trapped under Generic Power Law Potential in d Dimension

Test and performance optimization of nozzle inclination angle and swirl combustor in a low-tar biomass gasifier:a biomass power generation system perspective

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Carbon Resources Conversion 2022年第2期5卷 139-149页

作者： md Mashiur Rahman Agricultural Engineering Division Regional Agricultural Research StationBangladesh Agricultural Research InstituteJamalpur2000Bangladesh DTU Chemical Engineering Technical University of Denmark(DTU)Frederiksborgvej 399DK 4000 RoskildeDenmark

A nozzle inclination angle and swirl combustor inside the low-tar biomass(LTB)gasifier reactor were tested and optimized to evaluate these effects on tar reduction to design tar-free producer *** tar reduction process is mainly based on the concept of a swirling flow created by the nozzle inclination angle,with the inclination angle of 55◦to the radial line,allowing good mixing between pyrolysis gases and gasifying agents.A separate swirl combustor has created large internal annular and reverses flow zones with the help of swirl flow,resulting in homogenized temperature inside the combustor and providing longer residence time;both have a positive effect on the combustion of mixed gasifying air-pyrolysis gases by the thermal cracking in the partial oxidation *** ratio(RR)and combustion degree of volatiles are the two optimization parameters for evaluating the performance of NIA and swirl *** result observed that outstanding tar reduction occurred in this novel *** 86.5 and 12.8%of tar compounds are broken down in the partial oxidation zone and pyrolysis zone using the novel swirl combustor and NIA,respectively;gas outlet has observed producer gas having tar concentration of less than 1%.The optimization results reveal that a lower recycling ratio(recycle gas/gasifying air)and a higher combustion degree of volatiles perform better in biomass ***,this system generated producer gas with the tar concentration at an extremely low level of 7.4 mg/Nm^(3)for a biomass moisture content of 9%and appeared the lower heating value of 4.6–5.1 MJ/Nm^(3).This lower tar concentration might be directly coupled with an internal combustion engine or a gas turbine for power generation.

关键词： Biomass gasification Downdraft moving bed gasifier Nozzle inclination angle Swirl combustor Swirl flow Tar Reduction