Layered metal-organic polymer [Co(L)6](NO3)2 was obtained (where, L = C3H4N2) and structurally characterized by X-Ray diffraction (XRD) analysis. Crystals have trigonal structure: a = b = 12.3555(10) Ǻ, c = 14.4833(3) Ǻ; α = β = 90˚; γ = 120˚; V = 1914.78(5) Ǻ; R3, Z = 3. The structure of the complex consists of discrete [Co(L)6]2+ cations and anions. The Co2+ ion has a centrosymmetric octahedron configuration with a coordination site—CoN6. The ligand is coordinated monodentate through the pyridine nitrogen atom (N3) to the Co2+ ion with an average Co-N bond distance of 2.1590 Ǻ. Molecules in the coordination polymer are additionally linked by intermolecular hydrogen bonds through the pyrrole nitrogen atom (-N-H) and oxygen of the nitrate group with the formation of a polymer chain of the type: N-H…O. The chains are linked in layers along the (001) plane.
得到了层状金属有机聚合物[Co(L)6](NO3)2(其中L = C3H4N2)，并用x射线衍射(XRD)对其进行了结构表征。晶体具有三角形结构:a = b = 12.3555(10) Ǻ， c = 14.4833(3) Ǻ;α = β = 90˚;γ = 120˚;V = 1914.78(5) Ǻ;R3, z = 3。配合物的结构由离散的[Co(L)6]2+阳离子和阴离子组成。Co2+离子具有中心对称的八面体构型，配位位为con6。配体通过吡啶氮原子(N3)与Co2+离子呈单齿配位，Co-N平均键距为2.1590 Ǻ。配位聚合物中的分子通过吡咯氮原子(-N-H)和硝酸基的氧通过分子间氢键连接，形成了N-H…O型聚合物链。链沿(001)平面分层连接。
{"title":"Coordination Polymer of Cobalt (ΙΙ) Nitrate with Imidazole: Synthesis, Properties and Crystal Structure","authors":"Elmira Alamanova, Nasira Shyytyeva, Zhyldyz Berdalievа, Nurzat Abdyldaeva, Astra Duishonbaeva, Z. Abdullaeva","doi":"10.4236/jcpt.2021.101001","DOIUrl":"https://doi.org/10.4236/jcpt.2021.101001","url":null,"abstract":"Layered metal-organic polymer [Co(L)6](NO3)2 was obtained (where, L = C3H4N2) and structurally characterized by X-Ray diffraction (XRD) analysis. Crystals have trigonal structure: a = b = 12.3555(10) Ǻ, c = 14.4833(3) Ǻ; α = β = 90˚; γ = 120˚; V = 1914.78(5) Ǻ; R3, Z = 3. The structure of the complex consists of discrete [Co(L)6]2+ cations and anions. The Co2+ ion has a centrosymmetric octahedron configuration with a coordination site—CoN6. The ligand is coordinated monodentate through the pyridine nitrogen atom (N3) to the Co2+ ion with an average Co-N bond distance of 2.1590 Ǻ. Molecules in the coordination polymer are additionally linked by intermolecular hydrogen bonds through the pyrrole nitrogen atom (-N-H) and oxygen of the nitrate group with the formation of a polymer chain of the type: N-H…O. The chains are linked in layers along the (001) plane.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41947406","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 : 2021-01-01DOI: 10.4236/jcpt.2021.102002
Chao-Wan Chang, Chi-Rung Lee, Gene-Hsiang Lee
The synthesis and structures of two novel zwitterionic ruthenium triazolato complexes are reported. The treatment of the ruthenium azido complex [Ru]-N 3 (1, [Ru] = (η 5 -C 5 H 5 )(dppe)Ru, dppe = Ph 2 PCH 2 CH 2 PPh 2 ) with an excess of ethyl propiolate in CHCl 3 or CH 2 Cl 2 under ambient conditions for 15 days results in the formation of a mixture of the Z- and E-forms of N(1)-bound ruthenium 3-ethylacryl-4-carboxylate-3H-1,2,3-triazolato complexes [Ru]N 3 (CH=CHCO 2 Et)C 2 H(CO 2 ) (Z-3) and (E-3) in a ratio of ca. 5:2. The structures of E-3 and Z-3 were confirmed by single-crystal X-ray diffraction analysis and fully characterized by 1 H, 31 P, 13 C NMR and IR spectroscopy, mass spectrometry, and elemental analysis. The negatively charged carboxylate moieties of the zwitterionic ruthenium triazolato complexes Z-3 and Z-3 are highly nucleophilic and reactive toward a variety of electrophiles, making Z-3 and Z-3 potential starting materials for the development of biologically active 1,2,3-triazole derivatives.
报道了两种新型两性离子三唑钌配合物的合成及其结构。钌叠氮基的处理复杂[俄文]- N 3(1[俄文]=(η5 - C 5 H 5) (dppe)俄文,dppe Ph值= 2 PCH 2 CH 2、2)与过多的乙基propiolate CHCl 3或CH 2 Cl 2 15天导致环境条件下形成的混合物的Z - N的电子表单(1)绑定钌3-ethylacryl-4-carboxylate-3H-1, 2, 3-triazolato复合物[俄文]N 3 (CH = CHCO - 2等)C 2 H (CO 2) (Z-3)和(e - 3)在ca。5:2的比率。通过单晶x射线衍射分析证实了E-3和Z-3的结构，并通过1h、31p、13c核磁共振、红外光谱、质谱和元素分析对其结构进行了全面表征。阴离子型三唑钌配合物Z-3和Z-3的带负电羧酸部分具有高度亲核性和对多种亲电试剂的反应性，使Z-3和Z-3成为开发具有生物活性的1,2,3-三唑衍生物的潜在起始材料。
{"title":"Synthesis, Characterization and Crystal Structures of Zwitterionic Triazolato Complexes by Reaction of a Ruthenium Azido Complex with Excess Ethyl Propiolate","authors":"Chao-Wan Chang, Chi-Rung Lee, Gene-Hsiang Lee","doi":"10.4236/jcpt.2021.102002","DOIUrl":"https://doi.org/10.4236/jcpt.2021.102002","url":null,"abstract":"The synthesis and structures of two novel zwitterionic ruthenium triazolato complexes are reported. The treatment of the ruthenium azido complex [Ru]-N 3 (1, [Ru] = (η 5 -C 5 H 5 )(dppe)Ru, dppe = Ph 2 PCH 2 CH 2 PPh 2 ) with an excess of ethyl propiolate in CHCl 3 or CH 2 Cl 2 under ambient conditions for 15 days results in the formation of a mixture of the Z- and E-forms of N(1)-bound ruthenium 3-ethylacryl-4-carboxylate-3H-1,2,3-triazolato complexes [Ru]N 3 (CH=CHCO 2 Et)C 2 H(CO 2 ) (Z-3) and (E-3) in a ratio of ca. 5:2. The structures of E-3 and Z-3 were confirmed by single-crystal X-ray diffraction analysis and fully characterized by 1 H, 31 P, 13 C NMR and IR spectroscopy, mass spectrometry, and elemental analysis. The negatively charged carboxylate moieties of the zwitterionic ruthenium triazolato complexes Z-3 and Z-3 are highly nucleophilic and reactive toward a variety of electrophiles, making Z-3 and Z-3 potential starting materials for the development of biologically active 1,2,3-triazole derivatives.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70944012","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}
Crystal shape distribution, i.e. the multidimensional size distribution of crystals, is of great importance to their down-stream processing such as in filtration as well as to the end-use properties including the dissolution rate and bioavailability for crystalline pharmaceuticals. Engineering crystal shape and shape distribution requires knowledge about the growth behavior of different crystal facets under varied operational conditions e.g. supersaturations. Measurement of the facet growth rates and growth kinetics of static crystals in a crystallizer without stirring has been reported previously. Here attention is given to study on real-time characterization of the 3D facet growth behavior of crystals in a stirred tank where crystals are constantly moving and rotating. The measurement technique is stereo imaging and the crystal shape reconstruction is based on a stereo imaging camera model. By reference to a case study on potash alum crystallization, it is demonstrated that the crystal size and shape distributions (CSSD) of moving and rotating potash alum crystals in the solution can be reconstructed. The moving window approach was used to correlate 3D face growth kinetics with supersaturation (in the range 0.04 - 0.12) given by an ATR FTIR probe. It revealed that {100} is the fastest growing face, leading to a rapid reduction of its area, while the {111} face has the slowest growth rate, reflected in its area continuously getting larger.
{"title":"Real-Time Characterization of Crystal Shape and Size Distribution Based on Moving Window and 3D Imaging in a Stirred Tank","authors":"Rui Zhang, Xue-zhong Wang, Yang Zhang, Tao Liu","doi":"10.4236/jcpt.2019.92002","DOIUrl":"https://doi.org/10.4236/jcpt.2019.92002","url":null,"abstract":"Crystal shape distribution, i.e. the multidimensional size distribution of crystals, is of great importance to their down-stream processing such as in filtration as well as to the end-use properties including the dissolution rate and bioavailability for crystalline pharmaceuticals. Engineering crystal shape and shape distribution requires knowledge about the growth behavior of different crystal facets under varied operational conditions e.g. supersaturations. Measurement of the facet growth rates and growth kinetics of static crystals in a crystallizer without stirring has been reported previously. Here attention is given to study on real-time characterization of the 3D facet growth behavior of crystals in a stirred tank where crystals are constantly moving and rotating. The measurement technique is stereo imaging and the crystal shape reconstruction is based on a stereo imaging camera model. By reference to a case study on potash alum crystallization, it is demonstrated that the crystal size and shape distributions (CSSD) of moving and rotating potash alum crystals in the solution can be reconstructed. The moving window approach was used to correlate 3D face growth kinetics with supersaturation (in the range 0.04 - 0.12) given by an ATR FTIR probe. It revealed that {100} is the fastest growing face, leading to a rapid reduction of its area, while the {111} face has the slowest growth rate, reflected in its area continuously getting larger.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43821336","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}
A single scan has been performed in Differential Scanning Calorimetry (DSC) at a heating rate of 15oC/min under non-isothermal conditions to investigate the crystallization kinetics of glassy Se90Sb10-xAgx alloys (where x = 2, 4, 6, 8). For this purpose, Handerson’s theory based on non-isothermal method for thermal analysis of single-scan DSC data has been used. The activation energy of crystallization and order parameter has been determined and composition dependence of these parameters has been discussed.
{"title":"Application of Single Scan Differential Scanning Calorimetry Technique for Determination of Kinetic Parameters of Crystallisation in Se-Sb-Ag","authors":"N. Yaduvanshi, D. Kumar, N. Rastogi, Ashok Kumar","doi":"10.4236/JCPT.2019.91001","DOIUrl":"https://doi.org/10.4236/JCPT.2019.91001","url":null,"abstract":"A single scan has been performed in Differential Scanning Calorimetry (DSC) at a heating rate of 15oC/min under non-isothermal conditions to investigate the crystallization kinetics of glassy Se90Sb10-xAgx alloys (where x = 2, 4, 6, 8). For this purpose, Handerson’s theory based on non-isothermal method for thermal analysis of single-scan DSC data has been used. The activation energy of crystallization and order parameter has been determined and composition dependence of these parameters has been discussed.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47349057","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}
G. S. Pekar, A. F. Singaеvsky, M. M. Lokshin, I. Vasin, O. Dubikovskyi
Unconventional ways to improve the efficiency of purification of two different semiconductor materials of current interest, ZnO and Ge, are described. It is shown that, by using chemically assisted vapour transport of ZnO with carbon as a transporting agent, the degree of chemical purity of ZnO can be increased by more than an order of magnitude. It is also found that heating of the molten Ge in the experimentally determined narrow (about 20˚C wide) temperature range in which an intense evaporation of certain substances is observed, leads to a significant reduction of germanium contamination. As a result, a subsequent deep purification of pre-heat treated germanium by zone refining can be achieved at twice reduced (as compared with “non-treated” Ge) number of passes of a boat with germanium through the melting zones. Thus, the Ge purification process becomes faster, cheaper and more efficient.
{"title":"Improved Efficiency of ZnO and Ge Purification","authors":"G. S. Pekar, A. F. Singaеvsky, M. M. Lokshin, I. Vasin, O. Dubikovskyi","doi":"10.4236/jcpt.2019.93003","DOIUrl":"https://doi.org/10.4236/jcpt.2019.93003","url":null,"abstract":"Unconventional ways to improve the efficiency of purification of two different semiconductor materials of current interest, ZnO and Ge, are described. It is shown that, by using chemically assisted vapour transport of ZnO with carbon as a transporting agent, the degree of chemical purity of ZnO can be increased by more than an order of magnitude. It is also found that heating of the molten Ge in the experimentally determined narrow (about 20˚C wide) temperature range in which an intense evaporation of certain substances is observed, leads to a significant reduction of germanium contamination. As a result, a subsequent deep purification of pre-heat treated germanium by zone refining can be achieved at twice reduced (as compared with “non-treated” Ge) number of passes of a boat with germanium through the melting zones. Thus, the Ge purification process becomes faster, cheaper and more efficient.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70943886","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}
In the present work, undoped (SnO2) and fluorine-doped tin oxide (FTO) thin films were prepared by sol-gel process using a solution composed of (SnCl2, H2O), (NH4F), and ethanol mixture. The fluorine concentration effect on structural, optical and electrical properties of SnO2 films is investigated. The electrical properties of FTO films prepared by sol gel remain relatively lower than the ones deposited by other techniques. In present paper, we try to elucidate this difference. Films composition and the FTIR analysis, of films and formed precipitate during film growth, indicate that few amounts of fluorine are incorporated in SnO2 network, most of fluorine atoms remain in the solution. The films resistivity is reduced from 1.1 Ω·cm for undoped films to 3 × 10-2 Ω·cm for 50 wt.% doped FTO, but remains higher than the reported ones in the literature. This high resistivity is explained in terms of fluorine bonding affinity in the solution.
{"title":"Fluorine-Doped Tin Oxide Thin Films Deposition by Sol-Gel Technique","authors":"A. Adjimi, M. L. Zeggar, N. Attaf, M. Aida","doi":"10.4236/jcpt.2018.84006","DOIUrl":"https://doi.org/10.4236/jcpt.2018.84006","url":null,"abstract":"In the present work, undoped (SnO2) and fluorine-doped tin oxide (FTO) thin films were prepared by sol-gel process using a solution composed of (SnCl2, H2O), (NH4F), and ethanol mixture. The fluorine concentration effect on structural, optical and electrical properties of SnO2 films is investigated. The electrical properties of FTO films prepared by sol gel remain relatively lower than the ones deposited by other techniques. In present paper, we try to elucidate this difference. Films composition and the FTIR analysis, of films and formed precipitate during film growth, indicate that few amounts of fluorine are incorporated in SnO2 network, most of fluorine atoms remain in the solution. The films resistivity is reduced from 1.1 Ω·cm for undoped films to 3 × 10-2 Ω·cm for 50 wt.% doped FTO, but remains higher than the reported ones in the literature. This high resistivity is explained in terms of fluorine bonding affinity in the solution.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"08 1","pages":"89-106"},"PeriodicalIF":0.0,"publicationDate":"2018-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42804962","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}
Batch crystallization studies of curcumin from hydrotropic solutions of sodium cumenesulphonate (NaCS) and of cinnamic acid from a photosensitive hydrotropic medium of sodium cinnamate (Na-CIN) were carried out, in an agitated reactor for the effect of alternate heating and cooling cycles on crystal morphology. The crystal characterization by Scanning electron microscopy (SEM) and crystal size distribution (CSD) showed formation of spheroidal curcumin crystals while cinnamic acid formed porous aggregates when subjected to thermal cycles. The UV irradiation of cinnamic acid however showed no formation of the aggregates. The type of hydrotrope used and the initial crystal morphologies of curcumin and cinnamic acid are shown to be important factors to result in a different behaviour of the crystal morphology upon thermal cycles. The CSD data were effectively used for estimation of nucleation and growth rate parameters.
{"title":"Crystallization of Curcumin and Cinnamic Acid from Aqueous Solutions of Hydrotropes","authors":"N. Rathi, V. Gaikar","doi":"10.4236/jcpt.2018.83005","DOIUrl":"https://doi.org/10.4236/jcpt.2018.83005","url":null,"abstract":"Batch crystallization studies of curcumin from hydrotropic solutions of sodium cumenesulphonate (NaCS) and of cinnamic acid from a photosensitive hydrotropic medium of sodium cinnamate (Na-CIN) were carried out, in an agitated reactor for the effect of alternate heating and cooling cycles on crystal morphology. The crystal characterization by Scanning electron microscopy (SEM) and crystal size distribution (CSD) showed formation of spheroidal curcumin crystals while cinnamic acid formed porous aggregates when subjected to thermal cycles. The UV irradiation of cinnamic acid however showed no formation of the aggregates. The type of hydrotrope used and the initial crystal morphologies of curcumin and cinnamic acid are shown to be important factors to result in a different behaviour of the crystal morphology upon thermal cycles. The CSD data were effectively used for estimation of nucleation and growth rate parameters.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"8 1","pages":"73-87"},"PeriodicalIF":0.0,"publicationDate":"2018-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48335228","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}
An analytical investigation is conducted to study the effect of magnetic field on convection heat transfer through packed porous beds which consists of a horizontal fluid layer (river bed) and a porous zone with anisotropic permeability and underlined by a surface heated by a constant temperature T1. The free surface of the fluid layer overlying the horizontal porous layer receives solar rays to length of day and is then considered heated isothermally at temperature T2 such as T1 < T2. Flow in porous medium is assumed to be governed by the generalized Brinkman-extended Darcy law and in the fluid layer by the Navier-Stokes model. The Beavers-Joseph condition is applied at the interface between the two layers. The influence of Hartmann number and hydrodynamic anisotropy on the convective phenomenon is investigated analytically. It is found that the magnetic field, the anisotropic permeability and the thickness of the porous lining, e, have a strong influence of the geothermal convective flow and the heat transfer rate.
{"title":"Effect of Constant Magnetic Field on Convective Heat Transfer through Anisotropic River Beds","authors":"J. Yovogan, G. Degan, L. Fagbemi","doi":"10.4236/JCPT.2018.82004","DOIUrl":"https://doi.org/10.4236/JCPT.2018.82004","url":null,"abstract":"An analytical investigation is conducted to study the effect of magnetic field on convection heat transfer through packed porous beds which consists of a horizontal fluid layer (river bed) and a porous zone with anisotropic permeability and underlined by a surface heated by a constant temperature T1. The free surface of the fluid layer overlying the horizontal porous layer receives solar rays to length of day and is then considered heated isothermally at temperature T2 such as T1 < T2. Flow in porous medium is assumed to be governed by the generalized Brinkman-extended Darcy law and in the fluid layer by the Navier-Stokes model. The Beavers-Joseph condition is applied at the interface between the two layers. The influence of Hartmann number and hydrodynamic anisotropy on the convective phenomenon is investigated analytically. It is found that the magnetic field, the anisotropic permeability and the thickness of the porous lining, e, have a strong influence of the geothermal convective flow and the heat transfer rate.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"08 1","pages":"57-71"},"PeriodicalIF":0.0,"publicationDate":"2018-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44085055","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}
Purification is a primary application of zone melting, in which the improvement of efficiency, production yield and minimum achievable impurity level are always the research focus due to the increasing demand for high purity metals. This paper has systematically outlined the whole development of related research on zone refining of metals including basic theories, variants of zone refining, parametric optimization, numerical models, and high purity analytical methods. The collection of this information could be of good value to improve the refining efficiency and the production of high purity metals by zone refining.
{"title":"Production of High Purity Metals: A Review on Zone Refining Process","authors":"Xiaoxin Zhang, S. Friedrich, B. Friedrich","doi":"10.4236/JCPT.2018.81003","DOIUrl":"https://doi.org/10.4236/JCPT.2018.81003","url":null,"abstract":"Purification is a primary application of zone melting, in which the improvement of efficiency, production yield and minimum achievable impurity level are always the research focus due to the increasing demand for high purity metals. This paper has systematically outlined the whole development of related research on zone refining of metals including basic theories, variants of zone refining, parametric optimization, numerical models, and high purity analytical methods. The collection of this information could be of good value to improve the refining efficiency and the production of high purity metals by zone refining.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"8 1","pages":"33-55"},"PeriodicalIF":0.0,"publicationDate":"2018-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43578659","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}
M. Djihouessi, S. Onifade, M. Aina, H. Labité, F. P. Codo
This paper presented the first part of the studies about the development of a tool for groundwater contamination prediction, conducted by the Laboratory of Sciences and Technology of Water (UAC/Benin). The investigation made consisted in estimating the combined effect of retardation factor and biodegradation on migration processes of leachate, in the underlying soils of household waste dumpsites, without active safety barrier. Leachate infiltration tests for different initial conditions were made on soil columns and the breakthrough curves were traced for electrical conductivity, the 5 day biochemical oxygen demand (BOD5) and total kjeldahl nitrogen TKN. A mathematical migration model was developed and solved numerically by finite difference method and implemented with Matlab R2013a. Thus, the calibration of the model was made with electric conductivity data by determining the dispersion coefficient of the studied soils (D = 0.96 cm2/min). Simulations for model verification showed that the established model can perfectly predict the migration of biodegradable organic pollution (BOD5) but did not give conclusive results for the monitoring of nitrogenous organic matter (TKN). The influence of the retardation factor on the migration of biodegradable organic pollutants in soils was linear, while the biodegradation rate of the organic material on migration showed an exponential pattern.
{"title":"Migration of Biodegradable Organic Matter in Underlying Soils of Household Waste Dumpsites: A Case Study in Abomey-Calavi, Benin","authors":"M. Djihouessi, S. Onifade, M. Aina, H. Labité, F. P. Codo","doi":"10.4236/jcpt.2018.81002","DOIUrl":"https://doi.org/10.4236/jcpt.2018.81002","url":null,"abstract":"This paper presented the first part of the studies about the development of a tool for groundwater contamination prediction, conducted by the Laboratory of Sciences and Technology of Water (UAC/Benin). The investigation made consisted in estimating the combined effect of retardation factor and biodegradation on migration processes of leachate, in the underlying soils of household waste dumpsites, without active safety barrier. Leachate infiltration tests for different initial conditions were made on soil columns and the breakthrough curves were traced for electrical conductivity, the 5 day biochemical oxygen demand (BOD5) and total kjeldahl nitrogen TKN. A mathematical migration model was developed and solved numerically by finite difference method and implemented with Matlab R2013a. Thus, the calibration of the model was made with electric conductivity data by determining the dispersion coefficient of the studied soils (D = 0.96 cm2/min). Simulations for model verification showed that the established model can perfectly predict the migration of biodegradable organic pollution (BOD5) but did not give conclusive results for the monitoring of nitrogenous organic matter (TKN). The influence of the retardation factor on the migration of biodegradable organic pollutants in soils was linear, while the biodegradation rate of the organic material on migration showed an exponential pattern.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"08 1","pages":"18-32"},"PeriodicalIF":0.0,"publicationDate":"2018-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48876924","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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