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The Effects of Oxidation States and Spin States of Chromium Interaction with <i>Sargassum Sp</i>.: A Spectroscopic and Density Functional Theoretical Study

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Green and Sustainable Chemistry 2021年第4期11卷 125-141页

作者： Mohammad Abdul Matin md. Aftab Ali Shaikh md. anwar Hossain md. Alauddin Tapas Debnath Mohammed Abdul Aziz Centre for Advanced Research in Sciences (CARS) Dhaka University Dhaka Bangladesh Department of Chemistry Dhaka University Dhaka Bangladesh National University Gazipur Bangladesh Department of Theoretical and Computational Chemistry Dhaka University Dhaka Bangladesh

The study of various oxidation states of chromium with Sargassum sp. is of particular interest since hexavalent chromium is reduced to trivalent chromium in an aqueous solution. In this study, a systematic density functional theory (DFT) calculations were performed to study the interactions of transition metal chromium ion with different oxidation states and spin states with the Sargassum sp. decorated with carboxylate (acetate) at the wB97XD/6-311++ G(d,p) level of theory. The structures and binding energies of chromium metal-carboxylate complexes at various oxidation states and spin states in gas phase were examined. The coordination strength of Cr(VI) with the acetate ligand was predominantly the strongest compared to the other oxidation states. Vibrational frequency analysis, for the homoleptic monomers of tris [CrIII(AC)3]0 and [CrVI(AC)3]3+ complexes, illustrate good harmony with the experimen

关键词： Transition Metal Time Dependent Density Functional Theory Binding Energy Spectroscopy Electronic Properties and Homoleptic Coordinated Complex

Combine Harvester: Small Machine Solves Big Rice Harvesting Problem of Bangladesh

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Agricultural Sciences 2022年第2期13卷 201-220页

作者： Bidhan Chandra Nath Subrata Paul md.Durrul Huda md.anwar hossen MGK Bhuiyan AKM Saiful Islam Bangladesh Rice Research Institute Gazipur Bangladesh

Bangladesh, a country with 87% of rural households that depend on agriculture and rice dominated diets (70%), engages the country’s food security. Therefore, there is strong advocacy for a mechanized paddy harvesting system for food security in South Asia, mainly Bangladesh. Some harvesting machinery is available;however, the precise roles of a combine harvester during this process are little. This study attempts to understand the consequences of combining harvesters for paddy harvesting and compare them with hand harvesting. For comparison of field performance of combine harvester with traditional harvesting, the experiment was conducted at Gazipur District, Bangladesh, in 2016. Results showed that the labor required for harvesting unit area 283, 15 and 9.87 man-h∙ha−1 for T1 (Sickle + Head carry + Beating + Kula), T2 (Reaper + Trolley carry + Close drum thresher + winnower), T3 (Combine harvester) system, respectively. Likewise, the harvesting costs were 1.84 (T2) and 2.5 (T1) times higher than the combine harvester (T3). Also, the postharvest loss can be saved 1.84%, to use combine harvester over manual harvesting of paddy. The above result revealed that the semi-mechanized and mechanized harvesting system is a time, labor and cost-saving system;however, the manual reaping system is concerned with more postharvest losses (3.09%). This study highlights the importance of combine harvester;however, further research is required in other places with large and mini-combine harvesters under diverse cropping areas and to test a combine harvester’s detailed potentiality.

关键词： Combine Harvester Harvesting Labor Paddy Postharvest Losses

Prevalence of Antibiotic Resistant Bacteria on Tomato Surfaces and Effectiveness of Disinfectants in Reducing the Microbial Load

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Journal of Food Science and Engineering 2012年第5期2卷 293-300页

作者： Fauzia Ahmed Rupa Munawar Sultana Yasuhiro Inatsu md. Latiful Bari md. anwar Hossain Department of Microbiology University of Dhaka Dhaka 1000 Bangladesh Food Hygiene Research Laboratory National Food Research Institute 2-1-12 KannondaL Tsukuba-shi Ibaraki 305-8642 Japan Food Analysis and Research Laboratory Center for Advanced Research in Sciences University of Dhaka Dhaka 1000Bangladesh

This study was conducted to isolate and identify antibiotic resistant bacteria in fresh tomato sold in three different local markets of Dhaka city. On an average 〉 5.0 log CFU/g of natural microbial populations and coliform bacteria was present in the samples. Prevalence of Salmonella spp., E. coli, Listeria spp., and Yersinia spp., were recorded through cultivation dependent assay of tomato samples of different markets. Almost all of the isolates were uniformly resistant to rifampicin, erythromycin, clindamycin and oxacillin （100%）, vancomycin （93%）, amoxicillin （87%）, whereas 60% of the isolates were found to be resistant to ampicillin and cephalexin. Antibiotic sensitivity test of the presumptive E. coli and Salmonella spp. and corresponding plasmid profiling indicated a correlation of plasmid mediated multidrug resistance （md.） of these environmental bacteria. Washing with sanitizing agents such as acidified sodium chlorite （ASC） and 200 ppm chlorinated water was able to reduce _〈 2.0 log CFU/g of natural microflora and coliform bacteria. In contrast, ASC was able to reduce 〈 2.0 log CFU/g of other food borne pathogens and, chlorinated water was able to reduce up to undetectable level. Therefore, washing of tomato with 200 ppm chlorinated water could be useful in reducing the pathogen populations on tomatoes.

关键词： Antibiotic resistant bacteria acidified sodium chlorite chlorinated water E. coli O 157:H7 salmonella spp. tomato.

Research and Development of Surface Mounted Concentrator for Photovoltaic Solar Cell

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Research and Development of Surface Mounted Concentrator for...

作者： md.anwar Hossain 东华大学

学位级别：硕士

太阳辐射是人类活动的重要能量来源。太阳能电池是现今最重要的清洁能源之一,光伏（PV）电池消耗功率小,在世界能源领域拥有极好的应用潜力,但现今使用范围并不广泛,与其高额的系统成本息息相关。本论文给出一种低成本的表面聚光器（SM...

太阳辐射是人类活动的重要能量来源。太阳能电池是现今最重要的清洁能源之一,光伏（PV）电池消耗功率小,在世界能源领域拥有极好的应用潜力,但现今使用范围并不广泛,与其高额的系统成本息息相关。本论文给出一种低成本的表面聚光器（SMC）的设计,以降低太阳能电池的高额成本。本论文对比多种形态的聚光器,选取一种性能相对较好的聚光器,将光伏电池的效率提高20%以上。通过理论计算和实际检测,选择SMC和PV电池之间合理间距,确保SMC和PV电池紧密接触以防止PV电池被灼烧损坏。菲涅耳透镜聚光器是用于高浓度的强力聚光器之一,菲涅耳透镜用于低成本硅光伏电池组件进行结合,但由于实验条件有限,本论文根据聚光器参数以及低成本硅光伏电池特性建立光学模型,并完成仿真测试。本论文将菲涅耳透镜的像差和PV电池之间距离作为变量,观察光线强度和热量的变化。寻求一种较为理想的距离,并将聚光器固定在此位置。本论文未来工作将放置四个扩展的太阳能电池以覆盖PV电池四周,以收集由透镜和PV电池产生的漫射和反射光。本论文根据填充因子（FF）的取值范围以及太阳高度的不同对PV电池效率的影响,分析了聚光器的光学和几何特性,以及由外部环境因素导致的太阳能吸收率与PV电池的S MC面板倾斜角度的关系。提出了一种自适应控制算法,实现了对PV电池的SMC面板倾角最优化控制。

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A unified approach of PID controller design for unstable processes with time delay

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Journal of Central South University 2020年第9期27卷 2643-2661页

作者： Ashraf RAZA md.Nishat anwar Electrical Engineering Department National Institute of TechnologyPatna-800005India

This paper addresses a unified approach of the PID controller design for low as well as high order unstable processes with time *** design method is based on the direct synthesis(DS)approach to achieve the enhanced load disturbance *** improve the servo response,a two-degree of freedom control scheme has been considered.A suitable guideline has been provided to select the desired reference model in the DS *** direct synthesis controller has been approximated to the PID controller using the frequency response matching method.A consistently better performance has been obtained in comparison with the recently reported methods.

关键词： unstable process maximum sensitivity time delay higher order process direct synthesis method frequency response matching

An Improved SOI CMOS Technology Based Circuit Technique for Effective Reduction of Standby Subthreshold Leakage

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Circuits and Systems 2013年第6期4卷 431-437页

作者： Manish Kumar md. anwar Hussain Sajal K. Paul Department of Electronics and Communication Engineering North Eastern Regional Institute of Science and Technology Arunachal Pradesh India Department of Electronics Engineering Indian School of Mines Jharkhand India

Silicon-on-insulator (SOI) CMOS technology is a very attractive option for implementing digital integrated circuits for low power applications. This paper presents migration of standby subthreshold leakage control technique from a bulk CMOS to SOI CMOS technology. An improved SOI CMOS technology based circuit technique for effective reduction of standby subthreshold leakage power dissipation is proposed in this paper. The proposed technique is validated through design and simulation of a one-bit full adder circuit at a temperature of 27℃, supply voltage, VDD of 0.90 V in 120 nm SOI CMOS technology. Existing standby subthreshold leakage control techniques in CMOS bulk technology are compared with the proposed technique in SOI CMOS technology. Both the proposed and existing techniques are also implemented in SOI CMOS technology and compared. Reduction in standby subthreshold leakage power dissipation by reduction factors of 54x and 45x foraone-bit full adder circuit was achieved using our proposed SOI CMOS technology based circuit technique in comparison with existing techniques such as MTCMOS technique and SCCMOS technique respectively in CMOS bulk technology. Dynamic power dissipation was also reduced significantly by using this proposed SOI CMOS technology based circuit technique. Standby subthreshold leakage power dissipation and dynamic power dissipation were also reduced significantly using the proposed circuit technique in comparison with other existing techniques, when all circuit techniques were implemented in SOI CMOS technology. All simulations were performed using Microwindver 3.1 EDA tool.

关键词： Standby Subthreshold Leakage SOI Technology Low Power Multi-Threshold Voltage Stack Effect Reverse Gate Voltage

Robustness Study and Superior Method Development and Validation for Analytical Assay Method of Atropine Sulfate in Pharmaceutical Ophthalmic Solution

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American Journal of Analytical Chemistry 2024年第5期15卷 151-164页

作者： md. Nazmus Sakib Chowdhury Sreekanta Nath Dalal md. Ariful Islam md. anwar Hossain Pranab Kumar Das Shakawat Hossain Parajit Das Department of Pharmacy Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh Department of Applied Chemistry and Chemical Engineering University of Dhaka Dhaka Bangladesh Department of Applied Chemistry and Chemical Engineering University of Chittagong Chattogram Bangladesh Department of Applied Chemistry and Chemical Engineering Islamic University Kushtia Bangladesh Department of Applied Chemistry and Chemical Engineering University of Rajshahi Rajshahi Bangladesh Department of Pharmacy International Islamic University Chittagong Chittagong Bangladesh Department of Applied Chemistry and Chemical Engineering Bangabandhu Sheikh Mujibur Rahman Science and Technology University Gopalganj Bangladesh

Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical method variation parameters are based on pH variability of buffer solution of mobile phase, organic ratio composition changes, stationary phase (column) manufacture, brand name and lot number variation;flow rate variation and temperature variation of chromatographic system. The analytical chemical method for assay of Atropine Sulfate conducted for robustness evaluation. The typical variation considered for mobile phase organic ratio change, change of pH, change of temperature, change of flow rate, change of column etc. Purpose: The aim of this study is to develop a cost effective, short run time and robust analytical chemical method for the assay quantification of Atropine in Pharmaceutical Ophthalmic Solution. This will help to make analytical decisions quickly for research and development scientists as well as will help with quality control product release for patient consumption. This analytical method will help to meet the market demand through quick quality control test of Atropine Ophthalmic Solution and it is very easy for maintaining (GDP) good documentation practices within the shortest period of time. Method: HPLC method has been selected for developing superior method to Compendial method. Both the compendial HPLC method and developed HPLC method was run into the same HPLC system to prove the superiority of developed method. Sensitivity, precision, reproducibility, accuracy parameters were considered for superiority of method. Mobile phase ratio change, pH of buffer solution, change of stationary phase temperature, change of flow rate and change of column were taken into consideration for robustness study of the developed method. Results: The limit of quantitation (LOQ) of developed method was much low than the compendial method. The % RSD fo

关键词： Robustness Method Validation HPLC Compendial Method Method Development GDP LOQ

New Hybrid Digital Circuit Design Techniques for Reducing Subthreshold Leakage Power in Standby Mode

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Circuits and Systems 2013年第1期4卷 75-82页

作者： Manish Kumar md. anwar Hussain Sajal K. Paul Department of ECE North Eastern Regional Institute of Science & Technology Nirjuli Arunachal Pradesh India Department of Electronics Engineering Indian School of Mines Dhanbad Jharkhand India

In this paper, four new hybrid digital circuit design techniques, namely, hybrid multi-threshold CMOS complete stack technique, hybrid multi-threshold CMOS partial stack technique, hybrid super cutoff complete stack technique and hybrid super cutoff partial stack technique, have been proposed to reduce the subthreshold leakage power dissipation in standby modes. Techniques available in literature are compared with our proposed hybrid circuit design techniques. Performance parameters such as subthreshold leakage power dissipation in active and standby modes, dynamic power dissipation and propagation delay, are compared using existing and proposed hybrid techniques for a two input AND gate. Reduction of subthreshold leakage power dissipation in standby mode is given more importance, in comparison with the other circuit design performance parameters. It is found that there is reduction in subthreshold leakage power dissipation in standby and active modes by 3.5× and 1.15× respectively using the proposed hybrid super cutoff complete stack technique as compared to the existing multi-threshold CMOS (MTCMOS) technique. Also a saving of 2.50× and 1.04× in subthreshold leakage power dissipation in standby and active modes respectively were observed using hybrid super cutoff complete stack technique as compared to the existing super cutoff CMOS (SCCMOS) technique. The proposed hybrid super cutoff stack technique proved to perform better in terms of subthreshold leakage power dissipation in standby mode in comparison with other techniques. Simulation results using Microwind EDA tool in 65 nm CMOS technology is provided in this paper.

关键词： Subthreshold Leakage Power Standby Mode Active Mode Propagation Delay

Gold nanoparticles inhibit activation of cancer-associated fibroblasts by disrupting communication from tumor and microenvironmental cells

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Bioactive Materials 2021年第2期6卷 326-332页

作者： Yushan Zhang Chandra Kumar Elechalawar md.Nazir hossen Emmy RFrancek Anindya Dey Stefan Wilhelm Resham Bhattacharya Priyabrata Mukherjee Department of Pathology The University of Oklahoma Health Sciences CenterOklahoma CityOK73104USA Peggy and Charles Stephenson Cancer Center The University of Oklahoma Health Sciences CenterOklahoma CityOK73104USA Stephenson School of Biomedical Engineering University of OklahomaNormanOK73019USA Department of Obstetrics and Gynecology The University of Oklahoma Health Sciences CenterOklahoma CityOK73104USA Institute for Biomedical Engineering Scienceand Technology(IBEST)NormanOK73019USA

Cancer-associated fibroblasts(CAFs)are a major constituent of the tumor microenvironment(TME)and an important contributor to cancer progression and therapeutic *** of CAF activation is a promising strategy to influence cancer ***,we report that ovarian cancer cells(OCs)and TME cells promote the activation of ovarian CAFs,whereas gold nanoparticles(GNPs)of 20 nm in diameter inhibit the activation,as demonstrated by the changes in cell morphology,migration,and molecular *** exert the effect by altering the levels of multiple fibroblast activation or inactivation proteins,such as TGF-β1,PDGF,uPA and TSP1,secreted by OCs and TME ***,GNPs represent a potential tool to help understand multicellular communications existing in the TME as well as devise strategies to disrupt the communication.

关键词： Gold nanoparticle(GNP) Cancer-associated fibroblast(CAF) Tumor microenvironment(TME) Fibroblast activation Morphology Migration