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Effect of Bismuth Addition on Structure and mechanical Properties of Tin-9Zinc Soldering Alloy

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materials Sciences and Applications 2015年第9期6卷 792-798页

作者： muhommad Abdul Wadud m. A. gafur md. Rakibul Qadir mohammad Obaidur Rahman Department of Physics Jahangirnagar University Savar Bangladesh PP&PDC BCSIR Dhaka Bangladesh

Sn-Zn based solder is a possible replacement of Pb solder because of its better mechanical properties. The alloys need to be studied and explored to get a usable solder alloy having better properties. In this work eutectic Sn-9Zn and three Tin-Zinc-Bismuth ternary alloys were prepared and investigated their microhardness and mechanical properties. microhardness, tensile strength and elastic modulus increase with Bi addition while ductility decreases with Bi addition.

关键词： Lead Free Solder Alloy Eutectic Alloy microhardness

Effect of 3 mol% Yttria Stabilized Zirconia Addition on Structural and mechanical Properties of Alumina-Zirconia Composites

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materials Sciences and Applications 2017年第7期8卷 584-602页

作者： m. A. gafur md. Saifur Rahman Sarker md. Zahangir Alam m. R. Qadir PP & PDC BCSIR Dhaka Bangladesh Department of Chemistry Kurigram Govt. College Kurigram Rangpur Bangladesh Department of ACCE Dhaka University Dhaka Bangladesh

Alumina-Zirconia (Al2O3-ZrO2) composites especially Zirconia Toughened Alumina (ZTA) shows better mechanical properties over alumina. Al2O3-ZrO2 composites were prepared by powder compaction method varying 3 mol% yttria stabilized zirconia (3Y-ZrO2) content from 0 to 20 vol% using small amount of mgO as sintering aid. The composites were sintered for two hours in air at 1580°C. At this temperature maximum density was achieved 99.31% of theoretical density for composite containing 20 vol% 3Y-ZrO2. Density measurement of sintered composites was carried out using Archimedes’s method. Hardness and fracture toughness measurement was carried out using Vickers indentation. Phase content and t-ZrO2 retention were detected by means of X-ray diffraction (XRD). microstructure of the composites and grain size of alumina and zirconia was determined by Scanning Electron microscopic (SEm) analysis. maximum microhardness (17.46 GPa) was achieved for composite containing 5 vol% ZrO2 and maximum flexural strength (684.32 mPa) and fracture toughness (10.33 mPam0.5) was achieved for composite containing 20 vol% of 3Y-ZrO2. The aim of the present work is to investigate the optimum 3Y-ZrO2 content for obtaining maximum density, microhardness, flexural strength and fracture toughness of Al2O3-ZrO2 composites.

关键词： Alumina-Zirconia Composites Sintering t-ZrO2 Retention Grain Size

Study of the Physical, mechanical and Thermal Properties of Banana Fiber Reinforced HDPE Composites

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materials Sciences and Applications 2020年第4期11卷 245-262页

作者： Budrun Neher Rakib Hossain Kaniz Fatima m. A. gafur md. Abul Hossain Farid Ahmed Department of Physics Jahangirnagar University Dhaka Bangladesh Department of Physics Bangabandhu Sheikh Mujibur Rahman Science & Technology University Gopalganj Bangladesh PP and PDC Bangladesh Council of Scientific and Industrial Research Dhaka Bangladesh

Natural fiber reinforced composite materials are replacing the conventional materials, owing to their excellent physical, mechanical, electrical, and thermal properties. Also they increase biodegradability, reduce cost and decrease environmental pollution and hazards. In this study, obsolete high density polyethylene (HDPE) has used as polymer matrix and banana fiber as reinforcement material. Composites (5%, 10%, 15% and 20% of fiber contents) were made by hot press molding method by using Paul-Otto Weber Hydraulic press machine. The physical, mechanical and thermal properties of banana fiber-HDPE composites were studied and investigated the increment or decrement nature of different properties due to addition of banana fiber in BF-HDPE composites. The bulk density of composites increased with the increase wt. (%) of fiber content in composites. Water absorption ability of banana fiber and BF-HDPE composites also increased with the increase of wt. (%) of fiber content in composites and with socking time. Tensile strength of the BF-HDPE composites increased with the increase of fiber content in both cases (continuous aligned fiber orientation and continuous bidirectional fiber orientation). moreover, the tensile strength of BF-HDPE composites with continuous aligned fiber orientation was greater than that of continuous bidirectional fiber orientation. At first, the flexural strength increased for 5% BF-HDPE composites then the value decreased for other higher compositions. The flexural strength of continuous aligned fiber orientation was slightly greater than that of continuous bidirectional fiber orientation and composite with 5% banana fiber showed better flexural properties than others. Leeb’s rebound hardness decreased with the increase of fiber addition. Different thermal properties like TG/DTG, DTA of the obsolete HDPE and BF-HDPE composites were studied using thermo gravimetric analyzer and it was found that composite with 20% fiber content was more thermally

关键词： BF-HDPE Water Absorption Tensile Strength Hardness TG-DTG

The Development of ZnO Nanoparticle Coated Cotton Fabrics for Antifungal and Antibacterial Applications

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materials Sciences and Applications 2020年第9期11卷 601-610页

作者： Tanu Shree Roy Siraj Ud Daula Shamim md. Khalidur Rahman F. Ahmed m. A. gafur Department of Physics Bangladesh University of Textile Dhaka Bangladesh Department of Physics Mawlana Bhashani Science and Technology University Tangail Bangladesh Department of Electrical & Electronic Engineering Prime University Dhaka Bangladesh Department of Physics Jahangirnagar University Saver Dhaka Bangladesh PP & PDC Bangladesh Council of Scientific & Industrial Research (BCSIR) Dhaka Bangladesh

In the textile industry, cotton is the most popular choice among all the natural fibers due to its unique properties such as softness, affinity to skin, biodegradability, absorbency, and moisture being comfortable to wear. Zinc Oxide Nanoparticles (ZnO NPs) were produced and coated on cotton fabrics. The concentration of Zinc acetate was varied. 2-methoxy-ethanol has been used as a solvent. Using the dip coating technique, ZnO NPs have been coated on the cotton fabric in different mole concentrations. Scanning Electron microscopy (SEm), Ultraviolet Visible (UV-VIS) spectroscopy, the antifungal and antibacterial activity of the ZnO NPs was performed on the coated fabrics. The SEm images depicted that the nanoparticles are well dispersed on the fabric at 3m concentration of ZnO solution. It was found that the UV absorbance increases with the increase of concentration up to 2m concentration and after that it decreases. It was also found that maximum antibacterial and antifungal activity is at 2m concentration.

关键词： Nanoparticles ZnO Cotton SEm UV-VIS Antibacterial Antifungal

A Study of Fabrication Technique, Structural and morphological Behavior of Polypropylene Reinforced with Short Natural Fiber Banana

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Journal of Building material Science 2020年第2期2卷 1-8页

作者： mD.NAZRUL ISLAm m.a.gafur AmIR HOSSAIN KHAN Department of Physics Primeasia UniversityDhakaBangladesh PP and PDC BCSIRDhaka-1205Bangladesh Department of Physics Jahangirnagar University SavarBangladesh

Fiber reinforced polypropylene has been widely accepted as material for structural and engineering applications in recent ***,Banana fibers *** the most common low cost,versatile,renewable and abundantly available natural fibers which have biodegradable *** these fibers are versatile,renewable and most common agro based fibers that have enormous aspect due to their potentiality in composite *** comparison to other artificial fibers there are many advantages of natural fibers due to everyday applications such as,paperweight,suitcases,lampshades,helmets,and shower and bath *** and alkali treated banana fiber reinforced with Polypropylene matrix composite were fabricated with 10-25%loading of fiber by weight and were fabricated as Polypropylene Banana Composite(PPBC).Using melt mixing hot press molding technique these biodegradable composites were *** characteristics like morphologies and micro structural analysis of the composites were studied by Scanning electron microscope(SEm)and infrared spectroscopy instrument(IR).Due to the concept of group vibration infrared spectroscopy has the extensive *** kind of structural change such as addition or substitution of groups or atoms in a molecule may affect the relative mode of vibration of the *** causes change in IR spectral band position,change in relative intensities and appearance of new bands and disappearance of any band and splitting of a single band into two or more *** increase the utility of fiber infrared spectroscopy can also be *** deals with the interaction of infrared light with *** former can indicate the presence of functional groups qualitatively and the latter can provide a semi quantitative measure of their *** the other hand Electron microscopy is most widely used to obtain information regarding the morphology of fiber surfaces,especially SEm(Scanning Electron microscopy).Using SEm,it is easy to

关键词： Banana polypropylene composites Natural fiber Hot press molding Spectros-copy biodegradable matrix Infrared spectroscopy Functional groups morphology Surface topography

Conduction mechanism and Conductivity Behaviour of Pure Polypropylene (PP) and Polypropylene-Banana Fiber (PP-B) Composites

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Journal of Building material Science 2020年第2期2卷 16-20页

作者： md.Nazrul Islam m.a.gafur md.Amir Hossain Khan Department of Physics Primeasia UniversityBangladesh P.P&PDC BCSIRBangladesh Department of Physics Jahangir Nagar UniversityBangladesh

Fibers reinforced composite materials offer a combination of strength and modulus that are either comparable to or better than many traditional metallic *** research on natural fiber based composite materials fit well into this ecological *** paper reports the conduction mechanism and ac conductivity,activation energy behavior of Polypropylene and banana fiber reinforced thermoplastic ***[-CH_(2)-CH_(2)-CH_(2)-]n and different fiber content(wt.%)of polypropylene-banana fibers(natural fiber)composites were fabricated using a hot-press molding *** optimum fabrication parameters were established(initial pressure,***.).These composite test samples were fabricated so the short fibers were randomly oriented in the *** detail investigation of the *** and conduction mechanism of polymer composites would provide information about the relaxation processes,activation energy *** are dependent on frequency,temperature and *** activation energy involved in the above processes can also be estimated from this *** measurements were performed over a wide range of frequency of 60 Hz to 3 mHz and temperature range from 30℃(303°K)to 110℃(383°K).Experimental results of the ac properties of pure polypropylene and polypropylene-natural banana fiber composites were *** has been established that the fabricated composition changes its insulating property after adding the natural fibers and gives the better conductivity properties.

关键词： Composites Ac conductivity Dielectric constant Hopping conduction Interfacial polarization Activation energy

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果树越冬不同覆盖方法的成本计算

北方园艺 2012年第14期 197-200页

作者：李银芳潘伯荣孙永强阿迪力.吾彼尔郑建新方桂娟中国科学院新疆生态与地理研究所新疆乌鲁木齐830011 新疆阜康市林业局新疆阜康831501

为减轻果树越冬掩埋的劳动强度,推广塑料膜防寒覆盖法,对土埋和白塑料布、黑塑料布、彩条布覆盖的劳动力和材料成本进行了对比分析。结果表明:蟠桃土埋法需要强壮劳动力1 700元/667m2,塑料薄膜法只需要强壮劳动力450元/667m2;加材料费合... 详细信息

为减轻果树越冬掩埋的劳动强度,推广塑料膜防寒覆盖法,对土埋和白塑料布、黑塑料布、彩条布覆盖的劳动力和材料成本进行了对比分析。结果表明:蟠桃土埋法需要强壮劳动力1 700元/667m2,塑料薄膜法只需要强壮劳动力450元/667m2;加材料费合计:白塑料布单层覆盖690.0元/667m2,双层覆盖930.0元/667m2;黑塑料布单层覆盖814.8元/667m2,双层覆盖1 179.6元/667m2;彩条布单层覆盖862.8元/667m2,双层覆盖1 275.6元/667m2。葡萄土埋法需要强壮劳动力2.92元/m;塑料薄膜法只需要强壮劳动力0.74元/m,加材料费合计:白塑料布单层覆盖1.24元/m,双层覆盖1.74元/m;黑塑料布单层覆盖1.50元/m,双层覆盖2.26元/m;彩条布单层覆盖1.60元/m,双层覆盖2.46元/m。塑料薄膜法比土埋法便宜,其中白塑料布更便宜。同时提出,在环塔里木主产区和吐哈区的暖温带,应该根据气象部门秋季的长期天气预报,一般年份用单层覆盖都能安全越冬,预报寒冬的年份,应该进行双层覆盖。在中温带的北疆沿天山一带产区,也应根据气象部门秋季的长期天气预报,一般年份用单层覆盖都能安全越冬,预报寒冬或者晚降雪的年份,应该进行双层覆盖。

关键词：果树越冬覆盖覆盖物,成本