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Chinese Chemical Letters 2012年第8期23卷 981-984页

作者： Malihe Ahmadipour mohammad Ali Taher Hadi Beitollahi rahman Hosseinzadeh Department of Chemistry Shahid Bahonar University of KermanP.O.Box 76175-133KermanIran Young Researchers Society Shahid Bahonar University of KermanP.O.Box 76175-133KermanIran Environment Department Research Institute of Environmental SciencesInternational Center for ScienceHigh Technology&Environmental SciencesKermanIran Department of Organic Chemistry Faculty of ChemistryUniversity of MazandaranBabolsarIran

The electrooxidation of L-cysteine（L-Cys） was studied using a benzoylferrocene（BF） modified multi-wall carbon nanotube paste electrode（BFCNPE） using cyclic voltammetry（CV）,square wave voltammetry（SWV） and chronoamperometry（CHA）.Under optimum pH in CV the oxidation of L-Cys occurs at a potential about 215 mV less positive than that at the surface of unmodified carbon paste *** catalytic oxidation peak currents were dependent on the L-Cys concentration and a linear calibration curve was obtained in the range 0.7-350.0 mmol/L of L-Cys with SWV *** detection limit（3s） was determined as 0.1 mmol/*** method was also used for the determination of L-Cys in some real samples.

关键词： L-Cysteine Carbon paste electrode Carbon nanotubes Voltammetry

Bacterial endotoxins in periodontal health and diseases

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BIOCELL 2023年第1期47卷 81-89页

作者： FARIHA NUSRAT mohammad TARIQUR rahman MUHAMMAD MANJURUL KARIM Department of Mathematics and Natural Sciences BRAC UniversityDhaka1212Bangladesh Faculty of Dentistry University of MalayaKuala Lumpur50603Malaysia Department of Microbiology University of DhakaDhaka1000Bangladesh

Bacterial endotoxins are a major concern in periodontal health and diseases owing to their structure and biological *** up-to-date knowledge of endotoxins and the recent findings about the influence of endotoxins in dental health,their probable mode of pathogenesis,and standard detection methods,this review analyzes the potential efficacy and benefits of probiotics in combination with conventional and contemporary treatment *** the oral cavity,Gram-negative bacteria are documented to predominate in the pulpal lesions with radiolucent areas and in the root canal with pulp necrosis,where they pose an absolute threat by promoting a series of inflammatory ***,a constituent of Gram-negative bacteria establishes a nexus between cytokine stimulation and proinflammatory reactions,therefore plays a critical role in decaying dental pulp and modulating periodontal ***,the treatment regimen involves several biochemical *** addition,probiotics have been reported to control endotoxin in gingivitis and contribute to the overall improvement of dental health.A potential benefit of a combination of probiotics as a complementary treatment along with the conventional treatment warrant more empirical evidence to elucidate its role and mechanism in resolving the clinical manifestations associated with endotoxins in the periodontal region.

关键词： Dental health LPS Oral probiotics Periodontitis

Chloride ingress and macro-cell corrosion of steel in concrete made with recycled brick aggregate

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Frontiers of Structural and Civil Engineering 2021年第6期15卷 1358-1371页

作者： Tarek Uddin MOHAMMED Mahfuzur rahman Ahmed SABBIR mohammad Mehedi HASAN Abdullah Al MAMUN Department of Civil and Environmental Engineering Islamic University of TechnologyBoard BazarGazipur 1704Bangladesh Department of Civil Engineering University of Information Technology and SciencesBaridharaDhaka 1202Bangladesh Bangladesh Road Research Laboratory Roads and Highways DepartmentMirpurDhaka 1216Bangladesh

An investigation on chloride ingress and macro-cell corrosion of steel bars in concrete made with recycled brick aggregate(RBA)was carried *** control cases,virgin brick aggregate(BA)and stone aggregate(SA)were also *** cylindrical and cracked prism specimens were studied for 16 different *** prism specimens were made with a segmented steel bar providing electrical connection from outside of the specimens to measure macro-cell corrosion current continuously under seawater splash exposure for a period of 30 d using a data *** specimens were submerged in 3%NaCl solution at a temperature of 40℃ to investigate chloride ingress in concrete made with RBA,BA,and SA after 120 and 180 ***-cell potential,corrosion area,and depths of corrosion were also *** chloride ingress as well as corrosion of steel bars in concrete made with the different types of aggregate is ordered as RBA>BA>SA.

关键词： brick aggregate chloride ingress macro-cell corrosion recycled brick aggregate

Study the Structural, Electronic, Optical Properties of CZTS Compound after Doping Ba at Zn Site and Si at Sn Site Using Density Functional Theory (DFT)

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Materials Sciences and Applications 2024年第9期15卷 305-319页

作者： Fatema Najrin Rabeya Bakar Sarna Sayedul Hasan Shariful Islam Budrun Neher Md. Mahbubur rahman Bhuiyan Farid Ahmed Department of Physics Jahangirnagar University Bangladesh Department of Physics Sunamganj Science and Technology University Santiganj Bangladesh

The structural, electronic, and optical properties of Cu2Zn1−xBaxSn1−ySiyS4 compounds have been calculated using GGA-PBE function within the framework of Density Functional Theory (DFT). In the present work, lattice parameters remained the same, that is tetragonal crystal structure for 0% and 100% doping concentration. The electronic band gap of Cu2Zn1−xBaxSn1−ySiyS4 compounds has been gradually increased for continuous increment of doping concentration where the highest electronic band gap is 1.117 eV for Cu2BaSiS4 structure. Moreover, the band gap changes from direct to indirect band gap with the increase of doping concentration in the parent compound. The absorption coefficient has been found to be high (> 104 cm−1) in UV-region for all the doping concentration which makes the studied compound as a potential candidate of absorber layer in the UV detector. The theoretical study of the effect of double doping in the CZTS compound is very interesting for improving the quality of it and it would be a reference for the theoretical and experimental researchers.

关键词： Photovoltaics Absorber Layer Density Functional Theory (DFT) Band Gap Solar Cell

Removal of Dyes in Aqueous Media with Hydrochar Base of Solid Tanneries Waste: Optimization Process and Application

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Materials Sciences and Applications 2024年第7期15卷 168-185页

作者： Abdoul Ntieche rahman Gervais Ndongo Kounou Sakué Ngankam Eric Tamafo Fouegue Aymard Didier Kouotou Daouda Abdelaziz Baçaoui Department of Chemistry Higher Teacher Training College Bertoua The University of Bertoua Bertoua Cameroon Department of Fundamental Sciences Institute of Wood Technology of Mbalmayo University of Yaound I Balmayo Cameroon Department of Chemistry Faculty of Science Semlalia University of Cady Ayyad Marrakech Morocco

The Response Surface Methodology (RSM) was used to optimise the conditions of preparation of activated hydrochar from tannery solid waste by hydrothermal carbonisation (HTC). The main factors such as residence time, moisture content and final carbonisation temperature were investigated during the optimisation of hydrochar preparation conditions. The three responses investigated are hydrochar yield, iodine and methylene blue indices. The results of experimental analyses showed that the yield of hydrochar decreases with increasing final temperature, leading to the formation of micropores inside the carbonaceous solid. The optimum conditions for preparing the following hydrochar were obtained: 83.10%, 390.44 mg∙g−1 and 259.63 mg∙g−1 respectively for the hydrochar yield, the iodine and methylene blue indices. The specific surface area of prepared hydrochar is 849.160 m2/g, SEM micrographs showed a porous heterogeneous surface and particularly, the hydrochar surface also revealed external pores on the hydrochar surface which acted as a pathway to the micropores. Fourier transform infrared (FTIR), however, showed a predominance of acid functions on the surface of the carbonaceous solids. Tests were carried out to eliminate indigo carmine in aqueous media. Activated hydrochar showed a high level of activity, with the Langmuir and Freundlich isotherms giving an adsorption quantity of 354.610 mol/g and a KF constant of 468.2489, respectively. The findings of the research revealed that hydrochar produced is well adapted for dyes removal.

关键词： Response Surface Methodology Hydrochar Tannery Hydrothermal Carbonization Adsorption

Effect of Exchange-Correlation Functional on the Structural, Mechanical, and Optoelectronic Properties of Orthorhombic RbSrBr3 Perovskite

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Materials Sciences and Applications 2024年第6期15卷 137-154页

作者： Fatema Najrin Rabeya Bakar Sarna Md. Alamin Sarker Budrun Neher Md. Mahbubur rahman Bhuiyan Farid Ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Department of Electrical and Electronics Engineering Green University of Bangladesh Purbachal American City Kanchan Rupganj Narayanganj-1461 Dhaka Bangladesh

In the present study, the effect of the exchange-correlation functional on the structural, mechanical, and optoelectronic properties of orthorhombic RbSrBr3 perovskite has been investigated using various functionals in Density Functional Theory (DFT) with the CASTEP code. The optimized lattice parameters are quite similar for all the functionals. The electronic properties have shown that RbSrBr3 perovskite is a wide direct band gap compound with a band gap energy ranging from 4.296 eV to 4.494 eV for all the functionals. The mechanical parameters like elastic constants, Young’s modulus, Shear modulus, Poisson’s ratio, Pugh’s ratio, and an anisotropic factor reveal that the RbSrBr3 perovskite has ductile behavior and an anisotropic nature which signifies the mechanical stability of the compound. The Debye temperature might withstand lattice vibration heat. High absorption coefficient (>104 cm−1), high optical conductivity, and very low reflectivity have been found in the RbSrBr3 perovskite for all functions. The computed findings on the RbSrBr3 perovskite suggested that the presented studied material is potentially applicable for photodetector and optoelectronic devices.

关键词： Density Functional Theory Mechanical Properties Photodetector Ductility Anisotropic Factor

Multi-Pollutant Formation and Control in Pressurized Oxy-Combustion:SO_(x),NO_(x),Particulate Matter,and Mercury

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Engineering 2024年第8期39卷 127-153页

作者： Gaofeng Dai Jiaye Zhang Zia ur rahman Yufeng Zhang Yili Zhang Milan Vujanović Hrvoje Mikulčić Nebojsa Manic Aneta Magdziarz Houzhang Tan Richard L.Axelbaum Xuebin Wang MOE Key Laboratory of Thermo-Fluid Science and Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Ecology and Environment Hainan UniversityHaikou 570228China Faculty of Mechanical Engineering&Naval Architecture University of ZagrebZagreb 10000Croatia Faculty of Mechanical Engineering University of MariborMaribor 2000Slovenia Faculty of Mechanical Engineering University of BelgradeBelgrade 11120Serbia AGH University of Krakow Krakow 30059Poland Consortium for Clean Coal Utilization Department of EnergyEnvironmental&Chemical EngineeringWashington University in St.LouisSt.LouisMO 63130USA

Oxy-combustion is a promising carbon-capture technology,but atmospheric-pressure oxy-combustion has a relatively low net efficiency,limiting its application in power *** pressurized oxycombustion(POC),the boiler,air separation unit,flue gas recirculation unit,and CO_(2)purification and compression unit are all operated at elevated pressure;this makes the process more efficient,with many advantages over atmospheric pressure,such as low NO_(x)emissions,a smaller boiler size,and *** is also more promising for industrial application and has attracted widespread research interest in recent *** can produce high-pressure CO_(2)with a purity of approximately 95%,which can be used directly for enhanced oil recovery or ***,the pollutant emissions must meet the standards for carbon capture,storage,and *** of the high oxygen and moisture concentrations in POC,the formation of acids via the oxidation and solution of SO_(x)and NO_(x)can be increased,causing the corrosion of pipelines and ***,particulate matter(PM)and mercury emissions can harm the environment and human *** main distinction between pressurized and atmospheric-pressure oxy-combustion is the former’s elevated pressure;thus,the effect of this pressure on the pollutants emitted from POC—including SO_(x),NO_(x),PM,and mercury—must be understood,and effective control methodologies must be incorporated to control the formation of these *** paper reviews recent advances in research on SO_(x),NO_(x),PM,and mercury formation and control in POC systems that can aid in pollutant control in such systems.

关键词： Pressurized oxy-combustion Sulfur oxides Nitrogen oxides Particulate matter Mercury Direct contact cooler Carbon capture and sequestration

Deposition behavior and tribological properties of diamond-like carbon coatings on stainless steels via chemical vapor deposition

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1335-1343页

作者： Labani Mustafi M.M.rahman mohammad Nur E Alam Al Nasim mohammad Asaduzzaman Chowdhury M.H.Monir School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Engineering RMIT UniversityMelbourneVictoria 3001Australia Dhaka University of Engineering and Technology Gazipur 1707Bangladesh

A systematic investigation was carried out to observe the deposition rate of a diamond-like carbon(DLC) coating on two stainless steel substrates by chemical vapor deposition(CVD). The objective of this research is to study the deposition behavior of the DLC coating and its tribological properties in different combinations of methane(CH_4) and nitrogen, which were used as precursor gases. The results reveal that the deposition rate increases with increasing CH_4 content up to 50 vol%. The hardness of the DLC-deposited layer also increases while the friction coefficient decreases with increasing CH_4 gas content up to 50% in the precursor gas mixture.

关键词： diamond-like carbon chemical vapor deposition methane and nitrogen gas mixtures deposition rate hardness friction coefficient

Bilirubin sensor based on CuO-CdO composites deposited in a nafion/glassy carbon electrode matrixes

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Progress in Natural Science:Materials International 2017年第5期27卷 566-573页

作者： Mohammed M.rahman mohammad Musarraf Hussain Abdullah M.Asiri Chemistry Department King Abdulaziz UniversityFaculty of Science Center of Excellence for Advanced Material Research (CEAMR) King Abdulaziz University

Copper oxide-cadmium oxide nanocomposites(CuO-CdO NCs) were synthesized by solvothermal technique in a basic medium. CuO-CdO NCs were characterized using conventional techniques, such as Fourier Transform Infrared Spectroscopy(FTIR), UV–Visible Spectroscopy(UV/Vis), Field-Emission Scanning Electron Microscopy(FESEM), X-ray electron dispersive spectroscopy(XEDS), X-ray photoelectron spectroscopy(XPS), and powder X-ray diffraction(XRD). A selective and enzyme-less Bilirubin(BLR) sensor was developed with a thin-layer of NCs onto a glassy carbon electrode(GCE, surface area = 0.0316 cm~2) using 5% nafion binders at room conditions. Improved electrochemical performances of higher sensitivity, lower detection limit,linear dynamic range(LDR), and long-term stability of preferred BLR were achieved by a reliable currentvoltage(I-V) approach. The calibration curve was found linear(R~2= 0.9347) in a wide range of BLR concentration(10.0 pM ~ 10.0 mM). Based on the signal to noise ratio value of 3, the sensitivity and limit of detection(LOD) of the sensor were calculated as 95.0 pA μM-1cm-2and 1.0 ± 0.1 pM *** synthesized CuO-CdO NCs/GCE is an excellent advancement of developing a selective and sensitive BLR sensor by electrochemical approach and practically implemented in real sample applications.

关键词： CuO-CdO nanocomposites Bilirubin biosensor Glassy carbon electrode Sensitivity Real sample analysis Health care field

Characterization of a-Si:H/SiN multilayer waveguide polarization using an optical pumping application—LED

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第10期10卷 1421-1427页

作者： Mohd Saiful Dzulkefly ZAN Isamu KATO mohammad Syuhaimi AB-rahman Seri Mastura MUSTAZA Department of Electrical Electronic and System EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia Department of Electrical Engineering and Bioscience Waseda University

This paper describes the fabrication of a waveguide and the analysis of its polarization characteristics by applying light-emitting diode(LED) pumping lights to its *** using double tubed coaxial line(DTCL) microwave plasma chemical vapor deposition(MPCVD) equipment,an a-Si:H/SiN multilayer waveguide was fabricated whose thickness could be controlled at nanometer *** main structural material of the waveguide sample consisted of a combination of layers of amorphous silicon hydrogen and silicon *** the sample was ready,another major objective of the experiment was to analyze the polarization characteristics of the fabricated *** idea of the experiment was to analyze how the waveguide reacts when three types of LED(blue,yellow,and red) are radiated onto its *** results showed that the fabrication of the a-Si:H/SiN sample is *** effective transmission results,which accord with the polarization characteristics analysis,were obtained.

关键词： Waveguide Multilayer Optical pumping Light-emitting diode (LED) Double tubed coaxial line microwave plasma chemical vapor deposition (DTCL-MPCVD)