首页 > 最新文献

American Journal of Materials Science最新文献

英文 中文
Nucleation Controlled in the Aggregative Growth of Strontium Carbonate Microcrystals 碳酸锶微晶聚集生长中的成核控制
Pub Date : 2012-12-01 DOI: 10.5923/J.MATERIALS.20120205.02
B. Sreedhar, C. Vani, D. K. Devi, V. Sreeram, M. V. B. Rao
The in fluence of PABA(p-aminobenzoicacid) and HEEDTA (N-(2-hydro xyethyl) ethylenediamine- N, N, N- triacetic acid) on Strontionite crystals via simp le CO2 d iffusion route is described. The results showed that the experimental parameters have great influence on the shape evolution of products. The presence of templating species and varied pH are the key primary conditions for the g rowth morphology. Spike like crystals self assembled in the form of flo wer like and cauliflower shaped cluster with high crystallin ity were identified. The crystals undergo an interesting morphology changes and have been characterized by X-ray d iffraction (XRD), Scanning Electron M icroscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) techniques.
介绍了PABA(对氨基苯甲酸)和HEEDTA (N-(2-羟基乙基)乙二胺- N, N, N-三乙酸)通过简单的CO2注入途径对辉脱石晶体的影响。结果表明,实验参数对产品的形状演变有较大的影响。模板种的存在和pH的变化是影响其生长形态的主要条件。鉴定出花状自组装的穗状晶体和高结晶度的花椰菜状晶体。晶体发生了有趣的形态变化,并通过x射线衍射(XRD),扫描电子显微镜(SEM)和傅里叶变换红外光谱(FT-IR)技术进行了表征。
{"title":"Nucleation Controlled in the Aggregative Growth of Strontium Carbonate Microcrystals","authors":"B. Sreedhar, C. Vani, D. K. Devi, V. Sreeram, M. V. B. Rao","doi":"10.5923/J.MATERIALS.20120205.02","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120205.02","url":null,"abstract":"The in fluence of PABA(p-aminobenzoicacid) and HEEDTA (N-(2-hydro xyethyl) ethylenediamine- N, N, N- triacetic acid) on Strontionite crystals via simp le CO2 d iffusion route is described. The results showed that the experimental parameters have great influence on the shape evolution of products. The presence of templating species and varied pH are the key primary conditions for the g rowth morphology. Spike like crystals self assembled in the form of flo wer like and cauliflower shaped cluster with high crystallin ity were identified. The crystals undergo an interesting morphology changes and have been characterized by X-ray d iffraction (XRD), Scanning Electron M icroscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) techniques.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87571728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Cuinse 2 Solar Cells Efficiency Optimization 中国2太阳能电池效率优化
Pub Date : 2012-12-01 DOI: 10.5923/J.MATERIALS.20120205.05
N. Touafek, M. Aida, R. Mahamdi
In the present paper calculation of CuInSe2(CIS)/ CdS solar cell efficiency is presented. The influence of the thickness and the optical band gap of CdS and CIS layers on the solar cell performances are investigated. The thickness of CdS buffer layer, wh ich is generally neglected is taken into account. The solar cells performances calculat ions are based on the calculation, by means of developed software written with Matlab, o f photocurrent from the resolution of the well known three coupling equations: continuity equation for holes in the CdS (n-region) and fo r electrons in the CIS (p- region) and Poisson equation. The obtained results indicated that the solar cell efficiency can be improved by reducing the CdS thickness or by increasing the CIS thickness. The efficiency increasing rates are 0.01 %/ n m and 0.5 %/n m for CdS and CIS layer thickness respectively. The CdS layer alters the shorter wavelength of the solar spectrum, wh ile the CIS layer alters the longer wavelength. CIS layer optical band gap is the most crucial parameter by co mparison to the optical gap of CdS layer.
本文介绍了CuInSe2(CIS)/ CdS太阳能电池效率的计算。研究了CdS层和CIS层的厚度和光学带隙对太阳能电池性能的影响。考虑了通常被忽略的CdS缓冲层厚度。太阳能电池的性能计算是基于用Matlab编写的软件,根据众所周知的三个耦合方程:cd中空穴(n区)的连续性方程和CIS中电子(p区)的连续性方程和泊松方程的解析计算光电流。结果表明,减小CdS厚度或增加CIS厚度均可提高太阳能电池效率。cd层厚度和CIS层厚度的效率提高率分别为0.01% /n m和0.5% /n m。CdS层改变太阳光谱的短波长,而CIS层改变太阳光谱的长波长。与CdS层的光隙相比,CIS层的光带隙是最关键的参数。
{"title":"Cuinse 2 Solar Cells Efficiency Optimization","authors":"N. Touafek, M. Aida, R. Mahamdi","doi":"10.5923/J.MATERIALS.20120205.05","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120205.05","url":null,"abstract":"In the present paper calculation of CuInSe2(CIS)/ CdS solar cell efficiency is presented. The influence of the thickness and the optical band gap of CdS and CIS layers on the solar cell performances are investigated. The thickness of CdS buffer layer, wh ich is generally neglected is taken into account. The solar cells performances calculat ions are based on the calculation, by means of developed software written with Matlab, o f photocurrent from the resolution of the well known three coupling equations: continuity equation for holes in the CdS (n-region) and fo r electrons in the CIS (p- region) and Poisson equation. The obtained results indicated that the solar cell efficiency can be improved by reducing the CdS thickness or by increasing the CIS thickness. The efficiency increasing rates are 0.01 %/ n m and 0.5 %/n m for CdS and CIS layer thickness respectively. The CdS layer alters the shorter wavelength of the solar spectrum, wh ile the CIS layer alters the longer wavelength. CIS layer optical band gap is the most crucial parameter by co mparison to the optical gap of CdS layer.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86410153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Tensile Behavior of Cryorolled Zircaloy-2 低温锆合金-2的拉伸性能
Pub Date : 2012-12-01 DOI: 10.5923/J.MATERIALS.20120205.01
P. A. R. Kamalanath, A. Sarkar
Zircaloy-2 is mainly used in nuclear technology, as cladding of fuel rods in nuclear reactors, especially water reactors (BWRs). Hence high strength of Zirca loy-2 is of prime importance. This investigation deals with the effect of cryorolling on Zircaloy-2 by co mparing d ifferent tensile properties. For this analysis, four samp les with various degrees of cryorolling are taken and tensile tests are conducted on these samples. The obtained results are analyzed and the optimu m degree of cryorolling of Zircaloy-2 is obtained. The cryorolling imp roved the mechanical properties of the material as the dislocations are entangled near the grain boundaries and also due to decrease in the grain size. The microstructure of the sample is analysed by optical microscope, before and after cryorolling and the grain structure analysis is done.
锆-2主要用于核技术,作为核反应堆,特别是水堆(BWRs)燃料棒的包层。因此锆合金的高强度是至关重要的。通过对锆合金拉伸性能的比较,研究了低温轧制对锆合金拉伸性能的影响。为了进行分析,取了4个不同程度的冷轧试样,并对这些试样进行了拉伸试验。对所得结果进行了分析,得出了锆合金-2的最佳冷滚度。由于位错在晶界附近的缠结和晶粒尺寸的减小,低温轧制改善了材料的力学性能。用光学显微镜分析了样品的显微组织、冷轧前后的显微组织,并进行了晶粒组织分析。
{"title":"Tensile Behavior of Cryorolled Zircaloy-2","authors":"P. A. R. Kamalanath, A. Sarkar","doi":"10.5923/J.MATERIALS.20120205.01","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120205.01","url":null,"abstract":"Zircaloy-2 is mainly used in nuclear technology, as cladding of fuel rods in nuclear reactors, especially water reactors (BWRs). Hence high strength of Zirca loy-2 is of prime importance. This investigation deals with the effect of cryorolling on Zircaloy-2 by co mparing d ifferent tensile properties. For this analysis, four samp les with various degrees of cryorolling are taken and tensile tests are conducted on these samples. The obtained results are analyzed and the optimu m degree of cryorolling of Zircaloy-2 is obtained. The cryorolling imp roved the mechanical properties of the material as the dislocations are entangled near the grain boundaries and also due to decrease in the grain size. The microstructure of the sample is analysed by optical microscope, before and after cryorolling and the grain structure analysis is done.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75849842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 11
Effect of Heat Input on the Properties of Dissimilar Friction Stir Welds of Aluminium and Copper 热输入对铝、铜不同搅拌摩擦焊缝性能的影响
Pub Date : 2012-12-01 DOI: 10.5923/J.MATERIALS.20120205.03
E. Akinlabi, S. Akinlabi
Th is paper reports the effect of heat input on the resulting properties of joints between aluminiu m and copper produced with the friction stir weld ing process. The welds were produced using three different shoulder diameter tools, viz: 15, 18 and 25 mm by varying the rotational speed between 600 and 1200 rp m and the traverse speed between 50 and 300 mm/ min in order to vary the heat input to the welds. The microstructures, the grain sizes and the microhardness of the joint interfaces were characterised, and the electrical resistivities o f the jo ints were also measured. The resulting microstructural characterizat ion revealed that good metallurgical bonding was achieved at the jo int interfaces of the welds produced; this is evident with the presence of interlayers of aluminiu m and copper observed in the stir zones of the welds. The grains at the interfacial regions were recrystallized leading to a sharp decrease in the grain sizes compared to the parent materials. Higher Vickers microhardness values were measured at the joint interfaces resulting fro m strain hardening and the presence of intermetallics. It was also observed that the electrical resistivities of the jo ints increased as the heat input to the welds increases.
本文报道了热输入对搅拌摩擦焊接铝铜接头性能的影响。焊接使用三种不同的肩径工具,即:15、18和25毫米,通过在600到1200转/米之间改变转速,在50到300毫米/分钟之间改变导线速度,以改变焊缝的热量输入。对接头界面的显微组织、晶粒尺寸和显微硬度进行了表征,并测量了接头的电阻率。显微组织表征表明,所制备的焊缝在接合界面处实现了良好的冶金结合;在焊缝的搅拌区观察到铝和铜的夹层,这一点很明显。界面区晶粒发生再结晶,晶粒尺寸较母材明显减小。由于应变硬化和金属间化合物的存在,在接头界面处测得较高的维氏显微硬度值。还观察到,随着焊缝输入热量的增加,焊点的电阻率也会增加。
{"title":"Effect of Heat Input on the Properties of Dissimilar Friction Stir Welds of Aluminium and Copper","authors":"E. Akinlabi, S. Akinlabi","doi":"10.5923/J.MATERIALS.20120205.03","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120205.03","url":null,"abstract":"Th is paper reports the effect of heat input on the resulting properties of joints between aluminiu m and copper produced with the friction stir weld ing process. The welds were produced using three different shoulder diameter tools, viz: 15, 18 and 25 mm by varying the rotational speed between 600 and 1200 rp m and the traverse speed between 50 and 300 mm/ min in order to vary the heat input to the welds. The microstructures, the grain sizes and the microhardness of the joint interfaces were characterised, and the electrical resistivities o f the jo ints were also measured. The resulting microstructural characterizat ion revealed that good metallurgical bonding was achieved at the jo int interfaces of the welds produced; this is evident with the presence of interlayers of aluminiu m and copper observed in the stir zones of the welds. The grains at the interfacial regions were recrystallized leading to a sharp decrease in the grain sizes compared to the parent materials. Higher Vickers microhardness values were measured at the joint interfaces resulting fro m strain hardening and the presence of intermetallics. It was also observed that the electrical resistivities of the jo ints increased as the heat input to the welds increases.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86908421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 31
Biomimetic Mineralization of BaCO 3 Microstructures By Simple CO 2 Diffusion Method 基于简单co2扩散法的baco3微结构仿生矿化
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20120204.02
B. Sreedhar, C. Vani, D. K. Devi, V. Sreeram, M. V. B. Rao
Bariu m carbonate (BaCO3) microstructures have been synthesized in aqueous solution under ambient condi- tions with PABA (p-amino benzoic acid) and HEEDTA (N-(2 hydroxyethyl) ethylenediamine-N, N', N '' - triacetic acid) as simp le additives. In this study we demonstrate that the integration of both the additives, PABA and HEEDTA under different experimental conditions, such as crystallization sites and pH will extend the possibilities for controlling the shape and size on microstructures of the inorganic crystals by means of a slow CO2 simple d iffusion route. The influence of variation of pH condition with two different additives on the particle size and morphology was investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray powder diffracto metry were used to characterize the products. The results indicate that bunch like dendrit ic and limpet teeth shaped, BaCO3 microstructures were obtained. Increasing pH led to the separation of rods from the co mplex structures.
以PABA(对氨基苯甲酸)和HEEDTA (N-(2 -羟乙基)乙二胺-N, N′,N′-三乙酸)为简单添加剂,在常温条件下在水溶液中合成了碳酸钡(BaCO3)微结构。在本研究中,我们证明了添加剂PABA和HEEDTA在不同实验条件下的整合,如结晶位置和pH值,将扩大通过缓慢的CO2简单扩散途径控制无机晶体微观结构的形状和大小的可能性。考察了pH条件的变化对两种添加剂的粒径和形貌的影响。采用扫描电子显微镜、傅里叶变换红外光谱和x射线粉末衍射仪对产物进行了表征。结果表明,合金中获得了束状枝状和帽齿状的BaCO3显微组织。pH的增加导致棒状物从络合结构中分离。
{"title":"Biomimetic Mineralization of BaCO 3 Microstructures By Simple CO 2 Diffusion Method","authors":"B. Sreedhar, C. Vani, D. K. Devi, V. Sreeram, M. V. B. Rao","doi":"10.5923/J.MATERIALS.20120204.02","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120204.02","url":null,"abstract":"Bariu m carbonate (BaCO3) microstructures have been synthesized in aqueous solution under ambient condi- tions with PABA (p-amino benzoic acid) and HEEDTA (N-(2 hydroxyethyl) ethylenediamine-N, N', N '' - triacetic acid) as simp le additives. In this study we demonstrate that the integration of both the additives, PABA and HEEDTA under different experimental conditions, such as crystallization sites and pH will extend the possibilities for controlling the shape and size on microstructures of the inorganic crystals by means of a slow CO2 simple d iffusion route. The influence of variation of pH condition with two different additives on the particle size and morphology was investigated. Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray powder diffracto metry were used to characterize the products. The results indicate that bunch like dendrit ic and limpet teeth shaped, BaCO3 microstructures were obtained. Increasing pH led to the separation of rods from the co mplex structures.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79139535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Flexural properties of wheat straw reinforced polyester composites 麦秸增强聚酯复合材料的弯曲性能
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20110102.11
C. Dong, I. Davies
A study on the flexural properties of wheat straw reinforced polyester composites is presented in this paper. The wheat straw/polyester composites were made as per the hand layup procedure and the instructions provided by the manufacturers. These specimens were then tested in the three point bend configuration in accordance with ASTM D790-07 at a span to depth ratio of 16. Four weight fractions of wheat straw 2%, 4%, 6% and 8% were chosen to be studied. The process-induced voids were studied and it is shown that voids play an important role in flexural properties. When voids exist, flexural modulus was calculated using a micromechanical model. It is shown from both the experimental results and calculation that flexural modulus decreases with the addition of wheat straw, and this reduction in flexural modulus is due to process-induced voids. Flexural strength of polyester resins does not increase with the addition of wheat straw as rein- forcement. This is due to poor interfacial adhesion and the existence of voids. In order to achieve reinforcement, treatment of straw fibers and better processing techniques to reduce voids are needed.
对麦草增强聚酯复合材料的抗弯性能进行了研究。麦草/聚酯复合材料是按照手工铺层工艺和制造商提供的说明制作的。然后根据ASTM D790-07在跨度与深度比为16的三点弯曲配置下对这些试件进行测试。选取麦秸质量分数为2%、4%、6%和8%进行研究。研究了过程引起的孔洞,结果表明孔洞对材料的弯曲性能有重要影响。当存在空洞时,使用微力学模型计算弯曲模量。实验结果和计算结果都表明,麦秸的加入会导致弯曲模量的降低,而这种降低是由于加工过程中产生的空洞。聚酯树脂的抗弯强度不随麦秸的加入而增加。这是由于界面附着力差和空隙的存在。为了达到增强效果,需要对秸秆纤维进行处理,并采用更好的加工技术来减少空隙。
{"title":"Flexural properties of wheat straw reinforced polyester composites","authors":"C. Dong, I. Davies","doi":"10.5923/J.MATERIALS.20110102.11","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20110102.11","url":null,"abstract":"A study on the flexural properties of wheat straw reinforced polyester composites is presented in this paper. The wheat straw/polyester composites were made as per the hand layup procedure and the instructions provided by the manufacturers. These specimens were then tested in the three point bend configuration in accordance with ASTM D790-07 at a span to depth ratio of 16. Four weight fractions of wheat straw 2%, 4%, 6% and 8% were chosen to be studied. The process-induced voids were studied and it is shown that voids play an important role in flexural properties. When voids exist, flexural modulus was calculated using a micromechanical model. It is shown from both the experimental results and calculation that flexural modulus decreases with the addition of wheat straw, and this reduction in flexural modulus is due to process-induced voids. Flexural strength of polyester resins does not increase with the addition of wheat straw as rein- forcement. This is due to poor interfacial adhesion and the existence of voids. In order to achieve reinforcement, treatment of straw fibers and better processing techniques to reduce voids are needed.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90754007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 18
Optical Properties of 3,4,9,10-Perylenetetracarboxylic Diimide (PTCDI) Organic Thin Films as a Function of Post-Annealing Temperatures 3,4,9,10-苝四羧基二亚胺(PTCDI)有机薄膜的光学性质与退火后温度的关系
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20120204.06
M. El-Nahhas, H. Abdel-Khalek, E. Salem
In this work, effect of post-annealing on the structural and optical properties of thermally evaporated PTCDI films deposited on quartz substrates is reported. The optical properties were investigated using spectrophotometric measurements in wavelength range 200-2500 n m fo r as -deposited and annealed films with the same thickness at different temperatures. The XRD studies confirm the films have orthorhomb ic structure (PNA21) space group. The optical constants were accurately determined using reflectance and transmittance spectra. The dispersion of the refractive index is discussed in terms o f single oscillator model. In addition, the rat io of free carrier concentration to its effective mass was estimated. The absorption analysis has been also performed in order to determine the type of electronic inter-band transitions for the films. Both direct and indirect transitions are present. The direct and indirect bandgap energy decreases with increasing temperature. The decrease in the energy can be explained by increase of delocalized π electrons due to thermal annealing.
本文报道了后退火对石英衬底上热蒸发PTCDI薄膜结构和光学性能的影响。采用分光光度法在波长200 ~ 2500 nm范围内研究了在不同温度下沉积和退火的相同厚度薄膜的光学性质。XRD研究证实薄膜具有正交结构(PNA21)空间基团。利用反射光谱和透射光谱精确测定了光学常数。用单振子模型讨论了折射率的色散。此外,还估计了游离载流子浓度与有效质量的比值。为了确定薄膜的电子带间跃迁类型,还进行了吸收分析。直接和间接的过渡都存在。直接和间接带隙能量随温度的升高而减小。能量的降低可以解释为由于热退火导致离域π电子的增加。
{"title":"Optical Properties of 3,4,9,10-Perylenetetracarboxylic Diimide (PTCDI) Organic Thin Films as a Function of Post-Annealing Temperatures","authors":"M. El-Nahhas, H. Abdel-Khalek, E. Salem","doi":"10.5923/J.MATERIALS.20120204.06","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120204.06","url":null,"abstract":"In this work, effect of post-annealing on the structural and optical properties of thermally evaporated PTCDI films deposited on quartz substrates is reported. The optical properties were investigated using spectrophotometric measurements in wavelength range 200-2500 n m fo r as -deposited and annealed films with the same thickness at different temperatures. The XRD studies confirm the films have orthorhomb ic structure (PNA21) space group. The optical constants were accurately determined using reflectance and transmittance spectra. The dispersion of the refractive index is discussed in terms o f single oscillator model. In addition, the rat io of free carrier concentration to its effective mass was estimated. The absorption analysis has been also performed in order to determine the type of electronic inter-band transitions for the films. Both direct and indirect transitions are present. The direct and indirect bandgap energy decreases with increasing temperature. The decrease in the energy can be explained by increase of delocalized π electrons due to thermal annealing.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91094338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 23
Capacitive Behavior of Manganese Dioxide/Stainless Steel Electrodes at Different Deposition Currents 二氧化锰/不锈钢电极在不同沉积电流下的电容行为
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20120202.03
S. Hassan, Masa-aki Suzuki, A. El‐Moneim
Amorphous manganese dioxide thin films were prepared by galvanostatic cathodic deposition at current densities of 0.5-1 mA/cm 2 on etched stainless-steel substrate from 20 mM KMnO4 solution. The structure of the deposited oxides was investigated using X-ray diffraction analysis. The capacitive behavior of the manganese dioxide electrodes was characterized by cyclic voltammetry and electrochemical impedance spectroscopy in 0.5 M Na2SO4 electrolyte. The capacitive performance was found to increase with the increase in the deposition current density. The electrode deposited at current density of 1 mA/cm 2 showed specific capacitance of 174 F/g at a scan rate of 10 mV/s, equivalent series resistance of 3.53 Ω, and charge transfer resistance of 1.39 Ω. The improvement in the capacitive behavior of the electrode with the increase in the deposition current density was attributed to the increase in the electronic properties of the deposited oxides.
以20mm KMnO4溶液为基材,采用电流密度为0.5-1 mA/ cm2的恒流阴极沉积方法,在蚀刻不锈钢基体上制备了非晶二氧化锰薄膜。用x射线衍射分析研究了沉积氧化物的结构。用循环伏安法和电化学阻抗法表征了二氧化锰电极在0.5 M Na2SO4电解液中的电容行为。电容性能随沉积电流密度的增大而增大。在1 mA/ cm2电流密度下沉积的电极在扫描速率为10 mV/s时的比电容为174 F/g,等效串联电阻为3.53 Ω,电荷转移电阻为1.39 Ω。随着沉积电流密度的增加,电极的电容性能得到改善,这是由于沉积氧化物的电子性能提高所致。
{"title":"Capacitive Behavior of Manganese Dioxide/Stainless Steel Electrodes at Different Deposition Currents","authors":"S. Hassan, Masa-aki Suzuki, A. El‐Moneim","doi":"10.5923/J.MATERIALS.20120202.03","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20120202.03","url":null,"abstract":"Amorphous manganese dioxide thin films were prepared by galvanostatic cathodic deposition at current densities of 0.5-1 mA/cm 2 on etched stainless-steel substrate from 20 mM KMnO4 solution. The structure of the deposited oxides was investigated using X-ray diffraction analysis. The capacitive behavior of the manganese dioxide electrodes was characterized by cyclic voltammetry and electrochemical impedance spectroscopy in 0.5 M Na2SO4 electrolyte. The capacitive performance was found to increase with the increase in the deposition current density. The electrode deposited at current density of 1 mA/cm 2 showed specific capacitance of 174 F/g at a scan rate of 10 mV/s, equivalent series resistance of 3.53 Ω, and charge transfer resistance of 1.39 Ω. The improvement in the capacitive behavior of the electrode with the increase in the deposition current density was attributed to the increase in the electronic properties of the deposited oxides.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85477524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 33
Fabrication of Al7075/TiB 2 Surface Composite Via Friction Stir Processing 搅拌摩擦法制备Al7075/ tib2表面复合材料
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20110102.10
H. Bisadi, A. Abasi
In this work friction stir processing was utilized to successfully disperse and embed TiB2 particles with global size of 2.62 μm in Al 7075. The effects of rotational and traverse speeds with two FSP passes on particle distribution and microstructures were studied. Microstructure observations were carried out by employing optical microscopy and scanning electron microscopy (SEM) of the modified surface. The results showed that increasing the rotational speed caused a more uniform distribution of TiB2 Particles. Microhardness of the cross section and tensile test result were also evaluated. The microhardness values of produced composite surface raise with increasing the rotational and traverse speed and improved almost 3 times as compared with base aluminium. Tensile test result shows rising in yield strength by more than two times of base metal.
采用搅拌摩擦工艺成功地将粒径为2.62 μm的TiB2颗粒分散并嵌入到Al 7075中。研究了两个FSP通道的旋转和穿越速度对颗粒分布和微观结构的影响。利用光学显微镜和扫描电镜对改性后的表面进行了微观结构观察。结果表明,转速的增加使TiB2颗粒的分布更加均匀。并对截面显微硬度和拉伸试验结果进行了评价。复合材料表面的显微硬度值随着旋转和横移速度的增加而提高,与原铝相比提高了近3倍。拉伸试验结果表明,屈服强度提高了2倍以上。
{"title":"Fabrication of Al7075/TiB 2 Surface Composite Via Friction Stir Processing","authors":"H. Bisadi, A. Abasi","doi":"10.5923/J.MATERIALS.20110102.10","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20110102.10","url":null,"abstract":"In this work friction stir processing was utilized to successfully disperse and embed TiB2 particles with global size of 2.62 μm in Al 7075. The effects of rotational and traverse speeds with two FSP passes on particle distribution and microstructures were studied. Microstructure observations were carried out by employing optical microscopy and scanning electron microscopy (SEM) of the modified surface. The results showed that increasing the rotational speed caused a more uniform distribution of TiB2 Particles. Microhardness of the cross section and tensile test result were also evaluated. The microhardness values of produced composite surface raise with increasing the rotational and traverse speed and improved almost 3 times as compared with base aluminium. Tensile test result shows rising in yield strength by more than two times of base metal.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82534727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 25
Recyclable Copper Oxide Catalyzed Synthesis of N -Arylpyrroles from Arylhalides and Trans-4-Hydroxy-L-Proline 可回收氧化铜催化芳烃卤化物与反式-4-羟基- l -脯氨酸合成N -芳基吡咯
Pub Date : 2012-08-31 DOI: 10.5923/J.MATERIALS.20110102.16
R. Sridhar, M. Yedukondalu, N. Chandrasekhar, M. Rao
A facile and novel copper oxide nanoparticle catalyzed route has been developed for the synthesis of N-arylpyrroles, through tandem one-pot cross-coupling reaction of aryl halides and trans-4-hydroxy-L-proline, which is procured from natural source. This methodology is a first report of ligand free conditions and is a sustainable resource, via extrusion followed by redox amination. Catalyst used can be recovered and recycled up to five cycles with efficient activity.
利用天然来源的芳烃卤化物与反式-4-羟基- l -脯氨酸进行串联一锅交叉偶联反应,建立了一种简便、新颖的纳米氧化铜催化合成n -芳基吡咯的途径。这种方法是配体自由条件的第一份报告,是一种可持续的资源,通过挤压和氧化还原胺化。使用的催化剂可以回收和循环利用多达五次,具有高效的活性。
{"title":"Recyclable Copper Oxide Catalyzed Synthesis of N -Arylpyrroles from Arylhalides and Trans-4-Hydroxy-L-Proline","authors":"R. Sridhar, M. Yedukondalu, N. Chandrasekhar, M. Rao","doi":"10.5923/J.MATERIALS.20110102.16","DOIUrl":"https://doi.org/10.5923/J.MATERIALS.20110102.16","url":null,"abstract":"A facile and novel copper oxide nanoparticle catalyzed route has been developed for the synthesis of N-arylpyrroles, through tandem one-pot cross-coupling reaction of aryl halides and trans-4-hydroxy-L-proline, which is procured from natural source. This methodology is a first report of ligand free conditions and is a sustainable resource, via extrusion followed by redox amination. Catalyst used can be recovered and recycled up to five cycles with efficient activity.","PeriodicalId":7420,"journal":{"name":"American Journal of Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81201673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
American Journal of Materials Science
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1