Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.06
Xiangcheng Sun, Kai Sun, Caiyun Chen, Haiping Sun, B. Cui
Amo rphous carbon-coated lithiu m iron phosphate (C-LiFePO4) particles have been mass synthesized at the commercial scale by a controlled solid-state reaction method. Particles morphologies , o livine-type phase structures and the carbon coating features were investigated in details by various techniques as X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) imaging, and transmission electron microscopy (TEM, HRTEM ) imag ing, selected-area electron diffraction (SAED), X-ray energy dispersive spectroscopy microanalysis (XED S), and X-ray photoelectron spectroscopy (XPS). Single-crystal nature of the olivine type LiFePO4 structures was revealed by XRD and SA ED analyses. TEM imaging showed rough nanoparticles spherical features with average size range of 50-200 n m. Ho mogenous coating features of carbon layers on the particles surface and olivine-LiFePO4 phase are clearly observed in HR-TEM imaging and confirmed by the corresponding SAED pattern. Elemental b inding energy fro m XPS analysis also confirmed that an amo rphous sp2 carbon coating layer and olivine type LiFePO4 structures. It is indicated that the characteristics of sp2 type conducting-coating layer on the particles surfaces gave rise to improved electrical conductivity by reducing the diffusion path of the electron and lithiu m ions, as directly evidenced fro m our charge-discharge cycling testing as the cathode in the Lithiu m ion battery cell.
{"title":"Controlled Preparation and Surface Structure Characterization of Carbon-Coated Lithium Iron Phosphate and Electrochemical Studies as Cathode Materials for Lithium Ion Battery","authors":"Xiangcheng Sun, Kai Sun, Caiyun Chen, Haiping Sun, B. Cui","doi":"10.5923/J.IJMC.20120205.06","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.06","url":null,"abstract":"Amo rphous carbon-coated lithiu m iron phosphate (C-LiFePO4) particles have been mass synthesized at the commercial scale by a controlled solid-state reaction method. Particles morphologies , o livine-type phase structures and the carbon coating features were investigated in details by various techniques as X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) imaging, and transmission electron microscopy (TEM, HRTEM ) imag ing, selected-area electron diffraction (SAED), X-ray energy dispersive spectroscopy microanalysis (XED S), and X-ray photoelectron spectroscopy (XPS). Single-crystal nature of the olivine type LiFePO4 structures was revealed by XRD and SA ED analyses. TEM imaging showed rough nanoparticles spherical features with average size range of 50-200 n m. Ho mogenous coating features of carbon layers on the particles surface and olivine-LiFePO4 phase are clearly observed in HR-TEM imaging and confirmed by the corresponding SAED pattern. Elemental b inding energy fro m XPS analysis also confirmed that an amo rphous sp2 carbon coating layer and olivine type LiFePO4 structures. It is indicated that the characteristics of sp2 type conducting-coating layer on the particles surfaces gave rise to improved electrical conductivity by reducing the diffusion path of the electron and lithiu m ions, as directly evidenced fro m our charge-discharge cycling testing as the cathode in the Lithiu m ion battery cell.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"218-224"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.07
K. V. Rajulu, A. Nandanwar, M. C. Kiran
Smo ke density of wood based panel materials like General purpose plywood, Marine Plywood(BWP g rade), Medium Density Fibre Board (M DF), Bamboo Mat Board (BM B), Pre -laminated Part icle Board (PPB) were measured using chamber method (ASTM D 2843-70). The specimens are tested inside closed chamber and readings of light transmission were taken at 5-seconds interval. Measurements were made in terms of loss of light transmittance through an accumulated volu me of s moke. It was observed that pre-laminated particle board and general purpose plywood with 22.20% &22.47% of smo ke accumu lation area respectively resulted lower values as compared to other panel products such as marine plywood (BWP grade), MDF, BM B etc. A uniform rate of s moke build-up was recorded. Th is study provides the basis for predicting the smoke production rate, time to ignite (TTI), and To xicity index which can be developed by combustion of the wood product.
采用室内法(ASTM D 2843-70)测量了通用胶合板、船用胶合板(BWP g级)、中密度纤维板(M DF)、竹席板(BM B)、预层合零件板(PPB)等木基板材料的Smo密度。样品在密闭室内测试，每隔5秒读取透光率。测量是根据通过累积的体积体积的光透射损失来进行的。结果表明，与其他板材如船用胶合板(BWP级)、MDF、bmb等相比，smke累积面积分别为22.20%和22.47%的预层压刨花板和通用胶合板的smke累积值较低。记录到均匀的烟雾积聚速率。研究结果为预测木材燃烧后的产烟率、点燃时间(TTI)和to毒性指标提供了依据。
{"title":"Evaluation of Smoke Density on Combustion of Wood Based Panel Products","authors":"K. V. Rajulu, A. Nandanwar, M. C. Kiran","doi":"10.5923/J.IJMC.20120205.07","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.07","url":null,"abstract":"Smo ke density of wood based panel materials like General purpose plywood, Marine Plywood(BWP g rade), Medium Density Fibre Board (M DF), Bamboo Mat Board (BM B), Pre -laminated Part icle Board (PPB) were measured using chamber method (ASTM D 2843-70). The specimens are tested inside closed chamber and readings of light transmission were taken at 5-seconds interval. Measurements were made in terms of loss of light transmittance through an accumulated volu me of s moke. It was observed that pre-laminated particle board and general purpose plywood with 22.20% &22.47% of smo ke accumu lation area respectively resulted lower values as compared to other panel products such as marine plywood (BWP grade), MDF, BM B etc. A uniform rate of s moke build-up was recorded. Th is study provides the basis for predicting the smoke production rate, time to ignite (TTI), and To xicity index which can be developed by combustion of the wood product.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"225-228"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.03
M. Khairy, M. Mousa
Nanosized Cu 0.1Zn0.9 Mn2O4 were prepared by hydrothermal method in absence and presence of surfactants. The samples were characterized using XRD, SEM and TEM. A ll samp les showed spinel crystal structure with crystallite sizes depending on the preparation method and lay in the range of 17-89 n m. Electrical conductivity as a function of frequency and temperature has been studied. The conductivity results showed that all investigated samples behave like semiconductors and could be explained by hopping mechanism in which the conduction occurres via electron exchange amongst M n+ and M n+1 ions situated on octahedral sites in spinel lattice. Room temperature magnetic properties using VSM were studied. Effect of γ-radiation on the studied properties is investigated. Each of particle size, mo rphology, magnetic and electrical properties is affected with each of the type of surfactant used in the preparation method and γ- irradiat ion process.
在无表面活性剂和表面活性剂存在的情况下，采用水热法制备了Cu 0.1Zn0.9 Mn2O4纳米粉体。采用XRD、SEM和TEM对样品进行了表征。所有样品均显示尖晶石晶体结构，其晶粒大小取决于制备方法，在17-89 n m范围内。电导率作为频率和温度的函数已被研究。电导率结果表明，所研究的样品的导电行为与半导体相似，可以用跳变机制来解释，跳变机制是指尖晶石晶格中位于八面体位置的mn +和mn +1离子之间通过电子交换进行导电。用VSM研究了材料的室温磁性能。研究了γ辐射对材料性能的影响。每一种表面活性剂的制备方法和γ-辐照过程都影响其粒度、形貌、磁性和电学性能。
{"title":"Influences of γ–Radiation and Surfactants on Electrical and Magnetic Properties of Cu 0.1 Zn 0.9 Mn 2 O 4 Nanoparticles","authors":"M. Khairy, M. Mousa","doi":"10.5923/J.IJMC.20120205.03","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.03","url":null,"abstract":"Nanosized Cu 0.1Zn0.9 Mn2O4 were prepared by hydrothermal method in absence and presence of surfactants. The samples were characterized using XRD, SEM and TEM. A ll samp les showed spinel crystal structure with crystallite sizes depending on the preparation method and lay in the range of 17-89 n m. Electrical conductivity as a function of frequency and temperature has been studied. The conductivity results showed that all investigated samples behave like semiconductors and could be explained by hopping mechanism in which the conduction occurres via electron exchange amongst M n+ and M n+1 ions situated on octahedral sites in spinel lattice. Room temperature magnetic properties using VSM were studied. Effect of γ-radiation on the studied properties is investigated. Each of particle size, mo rphology, magnetic and electrical properties is affected with each of the type of surfactant used in the preparation method and γ- irradiat ion process.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"197-204"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.05
M. Sarker, M. M. Rashid, M. Molla, Muhammad Sadikur Rahman
The demand for fossil fuel is at an all t ime h igh worldwide. Annually ~30 billion barrels of petroleu m is being consumed worldwide. In this busy society, transportation is vital and, for transportation, petroleum is an obligation. All the major forms of business, agricultural, exports and imports depend on transportation. Transportation requires petroleum to function. Vehicles in the road require fuels, airway transportation requires Aviation fuel and sea transportation requires fuel oil. Fo r not only transportation but also, petroleum is required to make all kind of daily usable plastics. Deplet ion of petroleum is inevitable at th is current rate of consumption. Emissions released fro m evaporation and co mbustion of these fuel contributes to too many environ mental and health problems; including emitting greenhouse gases that contribute immensely to global warming. Annually ~7 billion tons of carbon dioxide is released to the environment due to petroleum emission. Moreover, when the plastics are discarded into the landfill, it becomes waste plastic and since plastic is non-biodegradable, it can remain in the landfill fo r thousands of year. Waste plastics presence in the landfill causes environmental problems e.g., it can cause soil to decay. Alternative source of energy created fro m Solar, W ind, Hydrogen Fuel, Bio mass Fuel, Bio-Diesel, Green Diesel, Bio-ethanol, and Geo-thermal has been proposed as a solution to these problems. A developed process of thermally breaking down the hydrocarbon of chains of plastic has been studied and imp lemented to produce a liquid fuel in the presence of activated carbon. The activated carbon acts as a filter to absorb dye from the waste plastic during the thermal process to increase the quality of the final product. This fuel can be used for all kinds of transportation, and will emit much less emission compared to the current commercial fuel and it will be cost effective.
{"title":"Method of Converting Municipal Proportional Waste Plastics into Liquid Hydrocarbon Fuel by Using Activated Carbon","authors":"M. Sarker, M. M. Rashid, M. Molla, Muhammad Sadikur Rahman","doi":"10.5923/J.IJMC.20120205.05","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.05","url":null,"abstract":"The demand for fossil fuel is at an all t ime h igh worldwide. Annually ~30 billion barrels of petroleu m is being consumed worldwide. In this busy society, transportation is vital and, for transportation, petroleum is an obligation. All the major forms of business, agricultural, exports and imports depend on transportation. Transportation requires petroleum to function. Vehicles in the road require fuels, airway transportation requires Aviation fuel and sea transportation requires fuel oil. Fo r not only transportation but also, petroleum is required to make all kind of daily usable plastics. Deplet ion of petroleum is inevitable at th is current rate of consumption. Emissions released fro m evaporation and co mbustion of these fuel contributes to too many environ mental and health problems; including emitting greenhouse gases that contribute immensely to global warming. Annually ~7 billion tons of carbon dioxide is released to the environment due to petroleum emission. Moreover, when the plastics are discarded into the landfill, it becomes waste plastic and since plastic is non-biodegradable, it can remain in the landfill fo r thousands of year. Waste plastics presence in the landfill causes environmental problems e.g., it can cause soil to decay. Alternative source of energy created fro m Solar, W ind, Hydrogen Fuel, Bio mass Fuel, Bio-Diesel, Green Diesel, Bio-ethanol, and Geo-thermal has been proposed as a solution to these problems. A developed process of thermally breaking down the hydrocarbon of chains of plastic has been studied and imp lemented to produce a liquid fuel in the presence of activated carbon. The activated carbon acts as a filter to absorb dye from the waste plastic during the thermal process to increase the quality of the final product. This fuel can be used for all kinds of transportation, and will emit much less emission compared to the current commercial fuel and it will be cost effective.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"208-217"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.01
P. Atanda, O. Adeniji, O. Oluwole
This report presents a prelimnary investigation into the development of heat treat ment refractory bricks using two local Nigerian clays. Ten different sample co mpositions of two different clay deposits from Awo (Egbedore local Govern ment) and Ipetumodu (Ife No rth Local Govern ment) areas of Osun State, Nigeria, were collected and analysed. The effect of Port land cement on the refractory properties of the clays was studied. The sample mixes of the clay and West African Portland Cement were prepared in varying proportions. Physical and thermal property tests such as thermal shock, thermal conductivity, apparent porosity, shrinkage and cold crushing strength were carried out on the samples. The prelimnary results obtained showed that the sample co mposition containing between 20% and 30% West African Port land Cement (WAPCO) of both samples can be used for the manufacture of heat treatment furnaces bricks by blending the addition with more non-linear expansivity materials to increase thermal shock resistance.
{"title":"Development of Heat Treatment Refractory Bricks Using Local Nigerian Clays","authors":"P. Atanda, O. Adeniji, O. Oluwole","doi":"10.5923/J.IJMC.20120205.01","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.01","url":null,"abstract":"This report presents a prelimnary investigation into the development of heat treat ment refractory bricks using two local Nigerian clays. Ten different sample co mpositions of two different clay deposits from Awo (Egbedore local Govern ment) and Ipetumodu (Ife No rth Local Govern ment) areas of Osun State, Nigeria, were collected and analysed. The effect of Port land cement on the refractory properties of the clays was studied. The sample mixes of the clay and West African Portland Cement were prepared in varying proportions. Physical and thermal property tests such as thermal shock, thermal conductivity, apparent porosity, shrinkage and cold crushing strength were carried out on the samples. The prelimnary results obtained showed that the sample co mposition containing between 20% and 30% West African Port land Cement (WAPCO) of both samples can be used for the manufacture of heat treatment furnaces bricks by blending the addition with more non-linear expansivity materials to increase thermal shock resistance.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"185-191"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-01-07DOI: 10.5923/J.IJMC.20120205.04
N. Shohoji
Recently, Noda and collaborators at Kyoto University reported possible enhancement of photo-voltaic cell (PVC) energy conversion efficiency by allowing penetration of preferential range of wavelength components alone to PVC by filtering the solar beam through a special semiconductor thin film developed at their laboratory. During the course of our recent experimental attempts ofnitridingd-group transition metals in N2 gas environment, we detected intriguing effects of colour-filtering on reaction product. In the present report, these effects of colour-filtering are reviewed under new light of recently reported evidence by Noda and co-workers. It appears that, by colour-filtering the selected wavelength range in solar beam, undesirable secondary reactions might be suppressed to result in promotion of a target reaction under heating using concentrated solar beam as the source of reaction heat.
{"title":"Effects of Colour-filtering Solar Beam on Reaction Product from d-group Transition Metals in N 2 Gas En vironme nt under Heating with Concentrated Solar Beam","authors":"N. Shohoji","doi":"10.5923/J.IJMC.20120205.04","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120205.04","url":null,"abstract":"Recently, Noda and collaborators at Kyoto University reported possible enhancement of photo-voltaic cell (PVC) energy conversion efficiency by allowing penetration of preferential range of wavelength components alone to PVC by filtering the solar beam through a special semiconductor thin film developed at their laboratory. During the course of our recent experimental attempts ofnitridingd-group transition metals in N2 gas environment, we detected intriguing effects of colour-filtering on reaction product. In the present report, these effects of colour-filtering are reviewed under new light of recently reported evidence by Noda and co-workers. It appears that, by colour-filtering the selected wavelength range in solar beam, undesirable secondary reactions might be suppressed to result in promotion of a target reaction under heating using concentrated solar beam as the source of reaction heat.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"205-207"},"PeriodicalIF":1.6,"publicationDate":"2013-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71252427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","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.IJMC.20120202.01
S. Bhatt, M. Uniyal
The samples of K1-xNaxNbO3 (X=0.4, 0.2, 0) ceramics (PSN) have been prepared by the conventional solid- state reaction method and sintering process. The prepared samples have been characterized by XRD. All the prepared samples show orthorhombic structure at room temperature. Dielectric and Electrical properties of PSN system have been investigated in the temperature range 45 0 C-245 0 C, and at 1MHz frequency. It is observed that dielectric constant, loss tangent and electrical conductivity increases with increasing temperature. Near the transition temperature dielectric constant, loss tangent and electrical conductivity of these samples show anomalous behaviour with temperature.
{"title":"Synthesis, Characterization and Dielectric Properties of K 1-x Na x NbO 3","authors":"S. Bhatt, M. Uniyal","doi":"10.5923/J.IJMC.20120202.01","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120202.01","url":null,"abstract":"The samples of K1-xNaxNbO3 (X=0.4, 0.2, 0) ceramics (PSN) have been prepared by the conventional solid- state reaction method and sintering process. The prepared samples have been characterized by XRD. All the prepared samples show orthorhombic structure at room temperature. Dielectric and Electrical properties of PSN system have been investigated in the temperature range 45 0 C-245 0 C, and at 1MHz frequency. It is observed that dielectric constant, loss tangent and electrical conductivity increases with increasing temperature. Near the transition temperature dielectric constant, loss tangent and electrical conductivity of these samples show anomalous behaviour with temperature.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"47-50"},"PeriodicalIF":1.6,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71251869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","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.IJMC.20120202.06
N. Nghia, Nguyen Ngoc Khoa Truong, N. M. Thong, N. P. Hung
Nanowire-shaped silver have been synthesized by the polyol process in ethylene glycol as a reductant, poly- vinylpyrrolidone (PVP) as a stabilizer, using a microwave technique. The products were characterized by transmission electron microscopy (TEM). The presence of sodium chloride in the polyol reduction of silver nitrate facilitated the pro- duction of silver nanowires. These wires were formed quickly (in approximately 3 minutes microwave heating). It was found that morphologies and sizes of silver nanostructures depended strongly on such experimental parameters as concentrations of PVP, NaCl, AgNO3, and heating time. The chloride ion was necessary to synthesize nanowire-shaped silver, and the sodium chloride likely controlled the rate of silver(I) reduction and initial seed formation. Among all the nanowire materials, the synthesis of silver nanowires has been and continues to be an area of active research because of their wide applications in catalysts, scanning probes, and various kinds of electronic and photonic nanodevices. Microwave-polyol method is a promising route for rapid preparation of metallic nanomate- rials(1). When microwave was irradiated into the mixture of AgNO3/NaCl/PVP in ethylene glycol solution, anisotropic Ag nanarods and nanowires were produced preferentially. In this work, we examined the dependence of shape, size of silver nanostructures on such experimental parameters as concentrations of PVP, NaCl, AgNO3, and heating time. The changes of shapes and sizes of silver nanostructures were observed by using transmission electron microscope (TEM). Possible formation mechanism of nanorods, nanowires, spherical and cubic nanoparticles under microwave (MW) irradiation in the presence of sodium chloride was discussed.
{"title":"Synthesis of Nanowire-Shaped Silver by Polyol Process of Sodium Chloride","authors":"N. Nghia, Nguyen Ngoc Khoa Truong, N. M. Thong, N. P. Hung","doi":"10.5923/J.IJMC.20120202.06","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120202.06","url":null,"abstract":"Nanowire-shaped silver have been synthesized by the polyol process in ethylene glycol as a reductant, poly- vinylpyrrolidone (PVP) as a stabilizer, using a microwave technique. The products were characterized by transmission electron microscopy (TEM). The presence of sodium chloride in the polyol reduction of silver nitrate facilitated the pro- duction of silver nanowires. These wires were formed quickly (in approximately 3 minutes microwave heating). It was found that morphologies and sizes of silver nanostructures depended strongly on such experimental parameters as concentrations of PVP, NaCl, AgNO3, and heating time. The chloride ion was necessary to synthesize nanowire-shaped silver, and the sodium chloride likely controlled the rate of silver(I) reduction and initial seed formation. Among all the nanowire materials, the synthesis of silver nanowires has been and continues to be an area of active research because of their wide applications in catalysts, scanning probes, and various kinds of electronic and photonic nanodevices. Microwave-polyol method is a promising route for rapid preparation of metallic nanomate- rials(1). When microwave was irradiated into the mixture of AgNO3/NaCl/PVP in ethylene glycol solution, anisotropic Ag nanarods and nanowires were produced preferentially. In this work, we examined the dependence of shape, size of silver nanostructures on such experimental parameters as concentrations of PVP, NaCl, AgNO3, and heating time. The changes of shapes and sizes of silver nanostructures were observed by using transmission electron microscope (TEM). Possible formation mechanism of nanorods, nanowires, spherical and cubic nanoparticles under microwave (MW) irradiation in the presence of sodium chloride was discussed.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"75-78"},"PeriodicalIF":1.6,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71251937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","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.IJMC.20120201.02
N. Shohoji
Chemical activities, a(X) and a(H), of constituents, X and H, in H2X type gas molecules (X = S or O) were evaluated as functions of temperature T and extent α of dissociation adapting a thermodynamic analysis procedure developed by Katsura for interpreting enhanced a(N) and a(H) in NH3 gas molecules with suppressed α by flowing. Present analysis results showed that both H2S and H2O gas molecules are chemically rather inert even at comparatively low α unlike nitro- gen-family tri-hydrides XH3 that were proved to yield high chemical activity of each constituent in a state being away from thermodynamic equilibrium. The parameter α referring to the extent of dissociation of HnX type gas molecules appears to be a significant parameter in evaluating the chemical activities, a(X) and a(H), in the HnX gas molecules that are remained non-dissociated.
{"title":"Chemical Activities, a(H) and a(X), of Constituents in H 2 X Type Gas Molecules (X = O or S) at Arbitrary Degree of Dissociation","authors":"N. Shohoji","doi":"10.5923/J.IJMC.20120201.02","DOIUrl":"https://doi.org/10.5923/J.IJMC.20120201.02","url":null,"abstract":"Chemical activities, a(X) and a(H), of constituents, X and H, in H2X type gas molecules (X = S or O) were evaluated as functions of temperature T and extent α of dissociation adapting a thermodynamic analysis procedure developed by Katsura for interpreting enhanced a(N) and a(H) in NH3 gas molecules with suppressed α by flowing. Present analysis results showed that both H2S and H2O gas molecules are chemically rather inert even at comparatively low α unlike nitro- gen-family tri-hydrides XH3 that were proved to yield high chemical activity of each constituent in a state being away from thermodynamic equilibrium. The parameter α referring to the extent of dissociation of HnX type gas molecules appears to be a significant parameter in evaluating the chemical activities, a(X) and a(H), in the HnX gas molecules that are remained non-dissociated.","PeriodicalId":14124,"journal":{"name":"International Journal of Mobile Communications","volume":"2 1","pages":"10-15"},"PeriodicalIF":1.6,"publicationDate":"2012-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71251799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"管理学","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.IJMC.20120203.01
O. AtandaP., O. Oluwole.O.
The production of Electrical porcelain by slip casting using Ikere-Ekiti Kaolin and clay fro m South Western Nigeria was the focus of this work. Atomic Absorbtion Spectrometric(AAS) analyses of samples of Ikere -Ekit i Kaolin and clay, Ile-Ife clay and Iwo Kaolin was done. AAS analyses showed Iwo Kao lin and Ile -ife clay having lo w alu mina and high impurity contents making them low refractory. Init ial tests confirmed its low refractoriness as Iwo Kao lin could not withstand the bisque firing at 900℃ cracking extensively. Thus Ile-ife clay and Iwo Kaolin were disqualified as candidate materials for electrical porcelain production. Ikere-Ekiti kao lin and clay found to be high in alu mina content and having low impurity contents were used in the experimental production. Results showed Ikere -Ekiti kaolin and clay suitable for porcelain pro- duction. Values of standard refractory tests fell with in standard values for porcelain production. Kaolin is commercial clay co mposed principally of the hydrated aluminosilicate clay mineral kaolinite. The co m- mercial value of kaolin is based on the mineral"s whiteness and fineness, but controllable part icle size wh ich may be optimized during processing. Particle size affects fluid ity, strength, plasticity, colour, abrasiveness and ease of disper- sion. Other important properties include the flat particle shape, which increases opacity and hiding power, its soft and non abrasive texture, due to the absence of coarser impurities, an its chemical inertness. These key properties distinguish kaolin fro m other kaolin itic clays like ball clay and fireclay. The kaolinite content of processed grades of kaolin varies, but is generally in the range of 75% to 94%. Associated minerals may have considerable influence on the suitability of the clay for a particular application. Kao lin fro m different parts of the world have markedly different properties. Kaolin has a chemical formu la of Al2Si2O5(OH)4. It is non - plastic with a Mohr scale hardness of 2 to 2.5. It has a dull and earthy luster and a refractive index o f α 1.553 - 1.565, β 1.559 - 1.569, γ 1.569 - 1.570, with a specific gravity of 2.16 - 2.68. The melting temperature is as h igh as over 1700℃ and it is triclin ic in its crystal system(1). On the other hand, ball clay is an earth material of very fine part icle size which forms as an end result of the the res idu e due to weat hering o r by hyd ro thermal act ion
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