Pub Date : 2012-12-01DOI: 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":"2 1","pages":"142-146"},"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}
Pub Date : 2012-12-01DOI: 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.
{"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":"127 1","pages":"160-164"},"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}
Pub Date : 2012-12-01DOI: 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.
{"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":"22 5 1","pages":"138-141"},"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}
Pub Date : 2012-12-01DOI: 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.
{"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":"61 1","pages":"147-152"},"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}
Pub Date : 2012-08-31DOI: 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.
{"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":"10 1","pages":"105-109"},"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}
Pub Date : 2012-08-31DOI: 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.
{"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":"7 1","pages":"71-75"},"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}
Pub Date : 2012-08-31DOI: 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.
{"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":"26 1","pages":"131-137"},"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}
Pub Date : 2012-08-31DOI: 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.
{"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":"23 1","pages":"11-14"},"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}
Pub Date : 2012-08-31DOI: 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.
{"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":"15 1","pages":"67-70"},"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}
Pub Date : 2012-08-31DOI: 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":"73 1","pages":"98-102"},"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}
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