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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

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

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

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

A Study on the Gas-Solid Particle Flows in a Needle-Free Drug Delivery Device

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Journal of Thermal Science 2013年第4期22卷 340-344页

作者： md.Alim Iftekhar Rasel md.Abu Taher H.D.Kim Department of Mechanical Engineering Andong National University

Different systems have been used over the years to deliver drug particles to the human skin for pharmaceutical effect. Research has been done to improve the performance and flexibility of these systems. In recent years a unique system called the transdermal drug delivery has been developed. Transdermal drug delivery opened a new door in the field of drug delivery as it is more flexible and offers better performance than the conventional systems. The principle of this system is to accelerate drug particles with a high speed gas flow. Among different transdermal drug delivery systems we will concentrate on the contour shock tube system in this paper. A contoured shock tube is consists of a rupture chamber, a shock tube and a supersonic nozzle section. The drug particles are retained between a set of bursting diaphragm. When the diaphragm is ruptured at a certain pressure, a high speed unsteady flow is initiated through the shock tube which accelerates the particles. Computational fluid dynamics is used to simulate and analyze the flow field. The DPM (discrete phase method) is used to model the particle flow. As an unsteady flow is initiated though the shock tube the drag correlation proposed by Igra et al is used other than the standard drag correlation. The particle velocities at different sections including the nozzle exit are investigated under different operating conditions. Static pressure histories in different sections in the shock tube are investigated to analyze the flow field. The important aspects of the gas and particle dynamics in the shock tube are discussed and analyzed in details.

关键词： Shock tube Drug delivery Contoured shock tube Unsteady flow Biolistics

Spatiotemporal variability of channel and bar morphodynamics in the Gorai-Madhumati River,Bangladesh using remote sensing and GIS techniques

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Frontiers of Earth Science 2020年第4期14卷 828-841页

作者： md.Yousuf Gazi Farhad Hossain Sumiya Sadeak md.Mahin Uddin Department of Geology University of DhakaDhaka1000Bangladesh Department of Geography and Environment University of DhakaDhaka1000Bangladesh

Bangladesh is a riparian country that is criss-crossed by the many tributaries and distributaries of the mighty Ganges,Brahmaputra,and Meghna river ***-Madhumati,a distributary of the Ganges River is an example where morphological development of the river is associated with frequent channel shifting within the catchment *** main objective of this research is to quantify the extent of channel migration,erosion-accretion,river width,sinuosity,and charland morpho-dynamics from 1972 to 2018 using geospatial techniques combined with satellite images and hydrological *** study also addressed the impacts of Farakka Barrage construction in India on the shifting,flow behavior,and siltation of Gorai-Madhumati *** study shows that bar surface areas have abnormally increased in both segments after 1975 due to the construction of Farakka *** flow in the Gorai-Madhumati has dropped remarkably in the downstream and instigated huge sedimentation in this *** of the time series satellite images revealed that the morphology of the river channel experienced huge changes simultaneously with the changes in the seasonal flow and sedimentation all over the study *** trend has frequently shifted and taken place in the NW and NE direction in the observed sections of the *** the study period,total amount of accretion was greater than the net percentage of erosion on both banks of the *** discharge,bar accretion,and erosion history show that the Gorai-Madhumati River will no longer exist with the present flowing condition without attention and proper river management.

关键词： channel migration erosion-accretion morphodynamics geospatial techniques Gorai-Madhumati Bangladesh

Evolution of river course and morphometric features of the River Ganga:A case study of up and downstream of Farakka Barrage

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International Soil and Water Conservation Research 2021年第4期9卷 578-590页

作者： md Nawaj Sarif Lubna Siddiqui md Safikul Islam Neha Parveen Monojit Saha Department of Geography Jamia Millia IslamiaNew DelhiIndia Centre for Earth Observation science University of ManitobaCanada

River channel shifting in the deltaic regime is an unabated *** shifting has become one of the concerns as it influences land use/land cover along the riverbank in various *** the management of the river,it is indispensable to study the pattern of river course change both in qualitative and quantitative *** study is an attempt to understand the pattern of shifting and to quantify erosion and deposition of the river Ganga at upstream and downstream of Farakka Barrage during *** study has been carried out by using various historical maps,aerial photographs,satellite imagery,and remote sensing and GIS technique to understand the dynamic of the *** 223 years period shifting of the river accentuates the remarkable oscillation of the *** of the river is determined to understand the area covered by the river course in the study *** evaluate the meandering of the river sinuosity of the river has been computed in this *** amount of erosion and deposition was calculated in this study by using ArcGIS *** study found a higher amount of erosion at the east bank where Manikchak,Kaliachak II and Kaliachak III blocks are situated between 1965 and *** the west bank of the river,especially the Rajmahal block,the occurrence of deposition was remarkable during the same period.

关键词： River shifting Sinuosity Ganga Erosion and Deposition Landsat

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