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Journal of Textile Science and Technology 2022年第4期8卷 203-220页

作者： md. razib sheikh md. Kawsar Hossain Mohammad Mahmudur Rahman Khan Department of Textile Engineering Bangladesh University of Business and Technology Dhaka Bangladesh Department of Textile Engineering Khulna University of Engineering and Technology Khulna Bangladesh

The physical and dimensional characteristics, i.e. course and wale spacing, stitch density, tightness factor, diameter, porosity, dimensional stability and bursting strength of single jersey knitted items containing lycra yarn with the variations in stitch length and lycra content have been examined and a detail investigation on the lycra filament has been discussed in this study. Six different samples were knitted with identical cotton and lycra yarn but different in lycra contents and stitch length. After conditioning in a controlled environment, all the samples were tested as per the established methods. After analyzing the test results, noticeable effects of variations in stitch length and lycra content on physical and dimensional characteristics of single jersey knitted fabric has been found. As smaller the stitch length and as greater the lycra content, the dimensional stability and bursting strength are better;on the other hand, the air permeability is lower.

关键词： Lycra Content Stitch Length Back Plaited Dimensional Stability Porosity Bursting Strength

An Overview on the Spinning Triangle Based Modifications of Ring Frame to Reduce the Staple Yarn Hairiness

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Journal of Textile Science and Technology 2020年第1期6卷 19-39页

作者： md. Khalilur Rahman Khan Hosne Ara Begum md. razib sheikh Department of Textile Engineering Bangladesh University of Business and Technology Dhaka Bangladesh Department of Yarn Engineering Bangladesh University of Textiles Dhaka Bangladesh

Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because of its detrimental effects on the subsequent processes (i.e., weaving, knitting, dyeing etc.) and the quality of resultant textile products. As a result, modified form of ring frame has attracted a lot of attention among the researchers for making yarn with the lower level of hairiness value. Besides the raw material parameters and some processing variables, spinning triangle (ST) is the most critical region that has decisive influence on the distribution of fiber tensions and their spatial orientations and shapes in staple yarn body. Thus, using appropriate methods to control the spinning triangle geometry actively has been a vital issue in the field of yarn hairiness reduction. In this paper, it is attempted to make an overview on the spinning triangle based modifications of ring frame that have been designed and destined to reduce hairiness. However, agent aided ring spinning system has also been briefly discussed in this paper as well.

关键词： Ring Frame Compact Spinning Spinning Triangle Yarn Hairiness

HBsAg, HBcAg, and combined HBsAg/HBcAg-based therapeutic vaccines in treating chronic hepatitis B virus infection

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Hepatobiliary & Pancreatic Diseases International 2013年第4期12卷 363-369页

作者： sheikh Mohammad Fazle Akbar Mamun Al-Mahtab Mohammad Helal Uddin md. Sakirul Islam Khan Department of Medical Sciences Toshiba General HospitalTokyo Japan Department of Hepatology Bangabandhu Sheikh Mujib Medical UniversityDhaka Bangladesh Clinical Research Organization Dhaka Bangladesh Laboratory of Animal Production Faculty of Agriculture Ehime UniversityMatsuyama Japan

BACKGROUND: As the host immunity is diminished in patients with chronic hepatitis B (CHB), different approaches have been used to up-regulate their immune responses to produce therapeutic effects. But, cytokines, growth factors and polyclonal immune modulators could not exhibit sufficient therapeutic effects in these patients. Immune therapy with HBV-related antigens (vaccine therapy) has been used in CHB patients. But there is a paucity of information about the design of HBV antigen-based immune therapy in these patients. DATA SOURCE: Preclinical and clinical studies on immune therapy with HBsAg-based vaccine, HBcAg and combination of HBsAg/HBcAg-based vaccines have been discussed. RESULTS: HBsAg-based prophylactic vaccine was used as an immune therapeutic agent in CHB patients; however, monotherapy with HBsAg-based immune therapy could not lead to sustained control of HBV replication and/or liver damages. HBsAg-based vaccine was used as a combination therapy with cytokines, growth factors, and antiviral drugs. HBsAg-based vaccine was also used for cell-based therapy. However, satisfactory therapeutic effects of HBsAg-based vaccine could not be documented in CHB patients. In the mean time, evidences have supported that HBcAg-specific immunity is endowed with antiviral and liver protecting capacities in CHB patients. Recent data concentrate on the clinical use of combined HBsAg- and HBcAg-based vaccines in CHB ***: Antigen-based immune therapy with HBV- related antigens may be an alternative method for the treatment of CHB patients but proper designs of antigens, types of adjuvants, dose of vaccinations, and routes of administration need further analyses for the development of an effective regimen of immune therapy against HBV.

关键词： chronic hepatitis B HBsAg vaccine HBsAg/HBcAg vaccine immune therapy therapeutic vaccines

Potential role of tubulin glutamylation in neurodegenerative diseases

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Neural Regeneration Research 2024年第6期19卷 1191-1192页

作者： Abdullah md.sheikh Shatera Tabassum Department of Laboratory Medicine Shimane University Faculty of MedicineShimaneJapan

The differentiation of neuronal stem cells into mature neurons is a complex process that involves both structural and functional *** cells undergo differentiation,there are notable functional changes,including the expression of various transcription factors,cytokines,and ***,structural changes occur as the cells develop various processes from the cell body and establish synaptic contacts with other cells.

关键词： diseases degenerative cytokines

Massive MIMO system lower bound spectral efficiency analysis with precoding and perfect CSI

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Digital Communications and Networks 2021年第3期7卷 342-351页

作者： Tasher Ali sheikh Joyatri Bora md.Anwar Hussain Department of Electronics and Communication Engineering North Eastern Regional Institute of Science and TechnologyNirjuliArunachal Pradesh791109India

The analytical lower bound of Spectral Efficiency(SE)of downlink transmission of the Massive Multiple Input Multiple Output(Ma-MIMO)system is *** this paper,we derive some novel and approximate mathematical expressions for the lower bound of the SE of a Ma-MIMO with linear precoding schemes,i.e.,Minimum Mean Square Error(MMSE)and Zero-Forcing(ZF).For simulation analysis of the SE,we consider three joint users and antenna scheduling algorithms,namely,the semi-orthogonal,random,and distance-based user scheduling algorithms,whereas the antennas are selected based on Maximum Signal to Noise Ratio(MSNR)with scheduled *** channel between the user and the transmitter is assumed to have characteristics of Small Scale Fading(SSF)and Large Scale Fading(LSF)with the Rayleigh fading *** investigate the effect of the variation of transmitting SNR,the number of base station antennas(M),and the radius(R)of the cell area on the *** simulate the downlink transmission of Ma-MIMO and compare the simulation and analytical *** is observed that the trends of variation of both results are similar to the variation of identical factors,and the difference between the simulated and analytical lower bounds of the SE is approximately 1-1.5 *** analytical lower bound is smaller than the simulation result.

关键词： Fifth-generation Spectral efficiency Ma-MIMO LSF coefficient Precoding

A Comparative Study of Heavy Metal Concentration in Different Layers of Tannery Vicinity Soil and Near Agricultural Soil

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American Journal of Analytical Chemistry 2016年第12期7卷 880-889页

作者： Ashiqur Rahaman Jahan Sadia Afroze Khairul Bashar md. Farhad Ali md. razib Hosen Institute of Leather Engineering and Technology University of Dhaka Dhaka Bangladesh

This research was conducted to bring out the appropriate level of heavy metal contamination in soil at the site of Buriganga river bank near the Hazaribagh tannery area and the normal agricultural area to evaluate heavy metal contamination in soil due to untreated tannery effluents. AAS flame method was used to determine the concentration of Chromium (Cr), lead (Pb), Cadmium (Cd), Zinc (Zn) in several depths of the soil. Results showed that, the heavy metal concentration in soil at the site of Buriganga river bank in the tannery vicinity and normal agricultural area significantly varies, such as Cr varies (561.71 - 31.23) mg/kg, Zn varies (158.23 - 73.5), Pb varies (70.58 - 24) and Cd varies (2.25 - 0.71) mg/kg in the river bank as well as in the normal agricultural area Cr varies (27.869 - 24.5416) mg/kg, Zn varies (134.167 - 28), Pb varies (25.76 - 22.49) and Cd varies (1.30 - 0.64) mg/kg. The study indicated that heavy metals concentration was found to be significantly higher in river bank soils than in the normal agricultural area. This metal concentration in soil is responsible for the promotion of toxicity in agricultural products. Therefore, the human health and environment are affected by these areas.

关键词： Heavy Metal Soil Contamination Tannery Area Agricultural Area

Capacity maximizing in massive MIMO with linear precoding for SSF and LSF channel with perfect CSI

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Digital Communications and Networks 2021年第1期7卷 92-99页

作者： Tasher Ali sheikh Joyatri Bora md.Anwar Hussain Department of Electronics and Communication Engineering Nordi Eastern Regional Institute of Science and TechnologyNirjuliArunachal Pradesh791109India

The capacity of a massive MIMO cellular network depends on user and antenna selection algorithms,and also on the acquisition of perfect Channel State Information(CSD).Low computational cost algorithms for user and an-tenna selection significantly may enhance the system capacity,as it would consume a smaller bandwidth out of the total bandwidth for downlink *** objective of this paper is to maximize the system sum-rate capacity with efficient user and antenna selection algorithms and linear *** consider in this paper,a slowly fading Rayleigh channel with perfect acquisition of CSI to explore the system sum-rate capacity of *** MIMO *** user selection,we apply three algorithms,namely Semi orthogonal user selection(SUS),Descending Order of SNR-based User Scheduling(DOSUS),and Random User Selection(RUS)*** all the user selection algorithms,the selection of Base Station(BS)antenna is based on the maximum Signal-to-Noise Ratio(SNR)to the selected *** users are characterized by having both Small Scale Fading(SSF)due to slowly fading Rayleigh channel and *** Fading(ISF)due to distances from the base ***,we use linear precoding techniques,such as Zero Forcing(ZF),Minimum Mean Square Error(MMSE),.and Maximum Ratio Transmission(MRT)to reduce interferences,thereby improving average system sum-rate *** using SUS,DOSUS,and RUS user selection algorithms with ZF,MMSE,and MRT precoding techniques are *** also analyzed and compared the computational complexity of all the three user selection *** computational complexities of the three algorithms that we achieved in this paper are 0(1)for RUS and DOSUS,and 0(M^2N)for suS which are less than the other conventional user selection methods.

关键词： Massive MIMO User selection Antenna selection Complexity DOSUS and antenna selection 5G

First Report of Pseudopestalotiopsis theae Causing Aloe vera Leaf Spot Disease in Bangladesh

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American Journal of Plant Sciences 2022年第2期13卷 193-204页

作者： md. Sabbir Ahmmed md. Maniruzzaman Sikder Satya Ranjan Sarker md. Sharif Hossain razib Datta Shubhra Nuhu Alam Department of Botany Faculty of Biological Sciences Jahangirnagar University Savar Bangladesh Department of Biotechnology and Genetic Engineering Faculty of Biological Sciences Jahangirnagar University Savar Bangladesh

Aloe vera (L.) Burm.f. is one of the important medicinal plants, has been commercially cultivated in the Northern part of Bangladesh. An experiment was conducted to detect A. vera leaf disease collected from Natore district, Bangladesh. Fungal leaf spot disease caused by Pseudopestalotiopsis theae (Sawada) Maharachch., K.D. Hyde & Crous was identified through morphological features and sequencing of internal transcribed spacer region of ribosomal DNA. After submitting nucleotide sequences to NCBI, we received an accession number MH333081.1: Pseudopestalotiopsis theae. The growth pattern of the isolated fungal pathogen was evaluated on different solid culture media, at different temperature and light conditions. The results showed the maximum mycelial growth of the fungus on the Richard Agar medium under the complete dark condition at 25°C. We evaluated fungal antagonists against the isolated pathogenic fungus, in which Trichoderma asperellum showed optimistic results. Synthetic fungicides—Tilt 250EC and Ridomil Gold completely inhibited the studied fungus’s vegetative growth. Pseudopestalotiopsis theae causing A. vera leaf spot disease in Bangladesh is a new record to the best of our knowledge.

关键词： Fungal Biology Molecular Growth Characters Bio-Control Agents Fungicides

Unsteady RANS simulation of wind flow around a building shape obstacle

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Building Simulation 2022年第2期15卷 291-312页

作者： sheikh Hassan md.Mamun Molla Preetom Nag Nasrin Akhter Amirul Khan Department of Mathematics&Physics North South UniversityDhaka 1229Bangladesh Department of Mathematics Dhaka University of Engineering&TechnologyGazipur 1708Bangladesh School of Civil Engineering University of LeedsLeeds LS29JTUK

This work aims to find the origin and connection of the surface,near-wake,and far-wake structures in the flow encompassing a high-rise building for a high Reynolds *** origin and interconnection of the stream-wise tip vortices,with the other components of the wake,is analysed in this study for the current *** Unsteady Reynolds Averaged Navier-Stokes equations(URANS)together with the realizable k-εturbulence model have been used in this investigation to study the turbulent wake flow following a ground-surface-attached square shape building.A moderately big obstacle aspect ratio of 4,a Reynolds number of 12,000,and a thin evolving boundary layer thickness have been used in the flow *** designed flow addresses the reversed-flows at the outlet during computation to improve the accuracy of the realizable k-e *** Reynolds stress components are retrieved using the Boussinesq *** wake’s principal compositions,including span-wise-side eddies and area of high stream-wise vorticity in the uppermost portion of the wake,are illustrated by both three-dimensional(3D)representations and planner projections of the mean flow distributions.A braided vortex formation,composed of asymmetric hairpin vortexes,is witnessed in the far-wake *** association of the near-wake vortex structures with the far-wake and near-wall flow,which is associated with the flow strengths,is also *** this investigation,few areas of large stream-wise vorticity magnitude,like tip vortexes,are correlated to the 3D curving of the fluid motion,and tip vortices did not continuously reach to the free end part of the *** 3D fluid motion interpretation,which combined several measurements of the flow distribution encompassing the cylinder,shows that the time-averaged near-wake structures are formed of two segments of distinct source and section of ***,addressing reversed-flow during computation shows notable improvement in the results.

关键词： turbulent wake vortex shedding flow structures tip vortexes model building URANS turbulent boundary layer

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