Mefenamic acid (MA) is a high-dose, anti-inflammatory, analgesic agent that is widely prescribed for pain related to menstrual disorders. It has some negative properties, such as a high hydrophobicity with a propensity to stick to surfaces, and possess great problems during granulation and tableting. Crystallization kinetics was investigated for mefenamic acid. Availability of data on the kinetics of crystal growth is very important for the development and operation of industrial crystallisation processes. The experiments for the measurement of crystal growth kinetics were carried out using the desupersaturation curve technique based on the measurement of the solution concentration versus time in a seeded isothermal batch experiment. To predict the optimum parameters (b, kb, g, kg) for the nucleation and growth kinetics from the desupersaturation curve obtained, the Population Balance Modelling was used and solved by the method of moments. The initial values for the optimisation problem were estimated by using the approach developed by Garside et al. (1982) [1].
{"title":"Optimum Kinetic Parameters of Mefenamic Acid Crystallization by PBM","authors":"C. Serap, Yaylaci Cihan","doi":"10.4236/JCPT.2012.23011","DOIUrl":"https://doi.org/10.4236/JCPT.2012.23011","url":null,"abstract":"Mefenamic acid (MA) is a high-dose, anti-inflammatory, analgesic agent that is widely prescribed for pain related to menstrual disorders. It has some negative properties, such as a high hydrophobicity with a propensity to stick to surfaces, and possess great problems during granulation and tableting. Crystallization kinetics was investigated for mefenamic acid. Availability of data on the kinetics of crystal growth is very important for the development and operation of industrial crystallisation processes. The experiments for the measurement of crystal growth kinetics were carried out using the desupersaturation curve technique based on the measurement of the solution concentration versus time in a seeded isothermal batch experiment. To predict the optimum parameters (b, kb, g, kg) for the nucleation and growth kinetics from the desupersaturation curve obtained, the Population Balance Modelling was used and solved by the method of moments. The initial values for the optimisation problem were estimated by using the approach developed by Garside et al. (1982) [1].","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"2012 1","pages":"81-95"},"PeriodicalIF":0.0,"publicationDate":"2012-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940461","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 design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.
{"title":"Design and Calculation for Test Tube with the Aim of Regulation Simultaneous Crystallization Tests","authors":"A. Janićijević, N. Danilović, B. Čabrić","doi":"10.4236/JCPT.2012.23016","DOIUrl":"https://doi.org/10.4236/JCPT.2012.23016","url":null,"abstract":"A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"02 1","pages":"121-123"},"PeriodicalIF":0.0,"publicationDate":"2012-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940374","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}
Single crystals of L-Valinium picrate were grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system. The optical transmission study reveals the transparency of the crystal in the entire visible region and the cut off wave length has been found to be 470 nm. The optical band gap is found to be 2.55 eV. The transmittance of L-Valinium picrate crystal has been used to calculate the refractive index (n), the extinction coefficient (K) and both the real (er) and imaginary (ei) components of the dielectric constant as functions of wavelength. Low dielectric loss at high frequency region is indicative of enhanced optical quality with lesser defects. Photoconductivity measurements carried out on the grown crystal reveal the negative photoconducting nature.
{"title":"Optical and Dielectric Studies on L-Valinium Picrate Single Crystal","authors":"P. Koteeswari, P. Mani, S. Suresh","doi":"10.4236/JCPT.2012.23015","DOIUrl":"https://doi.org/10.4236/JCPT.2012.23015","url":null,"abstract":"Single crystals of L-Valinium picrate were grown from aqueous solution by slow evaporation technique. Single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system. The optical transmission study reveals the transparency of the crystal in the entire visible region and the cut off wave length has been found to be 470 nm. The optical band gap is found to be 2.55 eV. The transmittance of L-Valinium picrate crystal has been used to calculate the refractive index (n), the extinction coefficient (K) and both the real (er) and imaginary (ei) components of the dielectric constant as functions of wavelength. Low dielectric loss at high frequency region is indicative of enhanced optical quality with lesser defects. Photoconductivity measurements carried out on the grown crystal reveal the negative photoconducting nature.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"2012 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2012-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940633","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}
The effect of annealing in air and oxygen on structural, electrical and optical properties of gallium doped ZnO thin films was investigated. The X-ray diffraction patterns showed that the films were highly preferentially oriented along (002) plane. After the heat treatment in air and oxygen environments, the intensity of (002) peak was apparently improved. It was found that heat treatment in air atmospheres lead to increase in surface roughness of the film. The GZO films annealed in oxygen at 673 K exhibited low resistivity of 4.21 × 10–3 Ω.cm, while the resistivity of film annealed in air showed a slightly higher value of 7.14 × 10–3 Ω.cm. In addition to this, all films have good optical transmittance about 80% in the visible region. It is found from the photoluminescence studies that the broad visible emissions in GZO films originated from the intrinsic shallow traps (VZn) and deep level vacancies (ZZi, OZn and Vo)
{"title":"Resistivity Stability of Ga Doped ZnO Thin Films with Heat Treatment in Air and Oxygen Atmospheres","authors":"T. Rao, M. Kumar","doi":"10.4236/JCPT.2012.22010","DOIUrl":"https://doi.org/10.4236/JCPT.2012.22010","url":null,"abstract":"The effect of annealing in air and oxygen on structural, electrical and optical properties of gallium doped ZnO thin films was investigated. The X-ray diffraction patterns showed that the films were highly preferentially oriented along (002) plane. After the heat treatment in air and oxygen environments, the intensity of (002) peak was apparently improved. It was found that heat treatment in air atmospheres lead to increase in surface roughness of the film. The GZO films annealed in oxygen at 673 K exhibited low resistivity of 4.21 × 10–3 Ω.cm, while the resistivity of film annealed in air showed a slightly higher value of 7.14 × 10–3 Ω.cm. In addition to this, all films have good optical transmittance about 80% in the visible region. It is found from the photoluminescence studies that the broad visible emissions in GZO films originated from the intrinsic shallow traps (VZn) and deep level vacancies (ZZi, OZn and Vo)","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"02 1","pages":"72-79"},"PeriodicalIF":0.0,"publicationDate":"2012-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940022","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}
C. Damour, M. Benne, L. Boillereaux, B. Grondin-Perez, J. Chabriat
This paper illustrates the benefits of a multivariable linearizing control approach applied to an industrial crystallization process. This relevant approach is declined according to two different strategies: first, a setpoint tracking is proposed for the couple crystal mass/concentration, whereas a second way consists in tracking of crystal content and concentration. The controlled variables, unavailable online, are issued from an observer developed in previous works. The performance of these strategies, which application to cane sugar crystallization constitutes a real novelty, are compared with experimental data issued from a PID-controlled industrial plant. The results reveal a significant improvement of energy efficiency, leading to an economy of more than 10% of energy.
{"title":"Energy Efficiency Improvement of an Industrial Crystallization Process Using Linearizing Control","authors":"C. Damour, M. Benne, L. Boillereaux, B. Grondin-Perez, J. Chabriat","doi":"10.4236/JCPT.2012.22007","DOIUrl":"https://doi.org/10.4236/JCPT.2012.22007","url":null,"abstract":"This paper illustrates the benefits of a multivariable linearizing control approach applied to an industrial crystallization process. This relevant approach is declined according to two different strategies: first, a setpoint tracking is proposed for the couple crystal mass/concentration, whereas a second way consists in tracking of crystal content and concentration. The controlled variables, unavailable online, are issued from an observer developed in previous works. The performance of these strategies, which application to cane sugar crystallization constitutes a real novelty, are compared with experimental data issued from a PID-controlled industrial plant. The results reveal a significant improvement of energy efficiency, leading to an economy of more than 10% of energy.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"02 1","pages":"44-54"},"PeriodicalIF":0.0,"publicationDate":"2012-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940249","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}
Trifkovic Milana, Rohani Sohrab, Sheikhzadeh Mehdi
In this work, solvent-mediated polymorphic transformation of metastable Form II to stable Form I of Buspirone Hy-drochloride (BUS-HCl) was studied. The polymorphic transformation was monitored using in-situ Raman spectroscopy. The solvent-mediated transformation process is governed by the dissolution of Form II and the nucleation and subsequent growth of Form I. The model parameters for each of these sub-processes were determined with the aid of experimental data including polymorphic fraction in solid phase, solute concentration, and the crystal size distribution. In order to estimate the kinetic parameters, independent seeded batch sets of experiments were conducted, first to estimate the growth rate of Form I, and consequently to estimate the secondary nucleation of Form I and dissolution rate of Form II. The experimental data showed that the secondary nucleation of Form I occurred slightly after the dissolution of Form II was initiated. The estimated parameters for growth, nucleation and dissolution rates were successfully implemented in the population model and validated with the experiments.
{"title":"Kinetics Estimation and Polymorphic Transformation Modeling of Buspirone Hydrochloride","authors":"Trifkovic Milana, Rohani Sohrab, Sheikhzadeh Mehdi","doi":"10.4236/JCPT.2012.22006","DOIUrl":"https://doi.org/10.4236/JCPT.2012.22006","url":null,"abstract":"In this work, solvent-mediated polymorphic transformation of metastable Form II to stable Form I of Buspirone Hy-drochloride (BUS-HCl) was studied. The polymorphic transformation was monitored using in-situ Raman spectroscopy. The solvent-mediated transformation process is governed by the dissolution of Form II and the nucleation and subsequent growth of Form I. The model parameters for each of these sub-processes were determined with the aid of experimental data including polymorphic fraction in solid phase, solute concentration, and the crystal size distribution. In order to estimate the kinetic parameters, independent seeded batch sets of experiments were conducted, first to estimate the growth rate of Form I, and consequently to estimate the secondary nucleation of Form I and dissolution rate of Form II. The experimental data showed that the secondary nucleation of Form I occurred slightly after the dissolution of Form II was initiated. The estimated parameters for growth, nucleation and dissolution rates were successfully implemented in the population model and validated with the experiments.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"2012 1","pages":"31-43"},"PeriodicalIF":0.0,"publicationDate":"2012-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940186","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 our work, ciprofloxacin was extracted from the raw material ciprofloxacin hydrochloride and coordinated with the metal ions of copper, manganese and zirconium. The procedures include the comparison of the autoclave method with the solvothermal method, synthesizing the corresponding complexes and conducting antibacterial test on nearly 20 kinds of bacteria. It is shown that under the condition of PH1 and 110℃ - 116℃, the autoclave method and solvothermal method can be utilized to obtain the ciprofloxacin complexes with Cu2+, Mn2+ and Zr2+ as the metal ligands after reacting for 8 hours. The raw material, ligands and monocrystals were characterized by IR, DSC, UV and fluorescence spectrum. Meanwhile a great number of antibacterial tests were carried out, revealing favorable bacteriocidal properties of the resulting complexes.
{"title":"The Synthesis, Characterization and Application of Ciprofloxacin Complexes and Its Coordination with Copper, Manganese and Zirconium Ions","authors":"Z. Tan, Feng-Jiao Tan, Li Zhao, Jun-Yong Li","doi":"10.4236/JCPT.2012.22008","DOIUrl":"https://doi.org/10.4236/JCPT.2012.22008","url":null,"abstract":"In our work, ciprofloxacin was extracted from the raw material ciprofloxacin hydrochloride and coordinated with the metal ions of copper, manganese and zirconium. The procedures include the comparison of the autoclave method with the solvothermal method, synthesizing the corresponding complexes and conducting antibacterial test on nearly 20 kinds of bacteria. It is shown that under the condition of PH1 and 110℃ - 116℃, the autoclave method and solvothermal method can be utilized to obtain the ciprofloxacin complexes with Cu2+, Mn2+ and Zr2+ as the metal ligands after reacting for 8 hours. The raw material, ligands and monocrystals were characterized by IR, DSC, UV and fluorescence spectrum. Meanwhile a great number of antibacterial tests were carried out, revealing favorable bacteriocidal properties of the resulting complexes.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"2012 1","pages":"55-63"},"PeriodicalIF":0.0,"publicationDate":"2012-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70939886","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}
Alloys of Se80-xTe20Inx glassy system are obtained by quenching technique and crystallization kinetics has been studied using Differential Scanning Calorimetric [DSC] technique. Well defined endothermic and exothermic peaks are ob- served at glass transition temperature (Tg) and crystallization temperature (Tc). From DSC scans, Tc is obtained at dif- ferent heating rates (5, 10, 15, 20, 25 K/min). It is observed that Tc increases with increasing heating rate for a particular glassy alloy. Activation energy of crystallization (Ec) has been calculated by different Non-isothermal Iso-conversional methods, i.e., Kissinger-Akahira-Sunose [KAS], Friedman, Flynn-wall-Ozawa [FWO], Friedman-Ozawa [FO] and Sta-rink methods. It is observed that Ec is dependent on extent of crystallization (α). Activation energy is also found to vary with atomic percentage of In in ternary Se80-xTe20Inx glassy system. The compositional dependence of Ec shows a re-versal in the trend at x = 15 in Se80-xTe20Inx, which is explained in terms of mechanically stabilized structure at this composition.
{"title":"Thermal Characterization of Se80-xTe20Inx Glasses Using Iso-Conversional Methods","authors":"Renu Shukla, Pragya Agarwal, Ashok Kumar","doi":"10.4236/JCPT.2012.22009","DOIUrl":"https://doi.org/10.4236/JCPT.2012.22009","url":null,"abstract":"Alloys of Se80-xTe20Inx glassy system are obtained by quenching technique and crystallization kinetics has been studied using Differential Scanning Calorimetric [DSC] technique. Well defined endothermic and exothermic peaks are ob- served at glass transition temperature (Tg) and crystallization temperature (Tc). From DSC scans, Tc is obtained at dif- ferent heating rates (5, 10, 15, 20, 25 K/min). It is observed that Tc increases with increasing heating rate for a particular glassy alloy. Activation energy of crystallization (Ec) has been calculated by different Non-isothermal Iso-conversional methods, i.e., Kissinger-Akahira-Sunose [KAS], Friedman, Flynn-wall-Ozawa [FWO], Friedman-Ozawa [FO] and Sta-rink methods. It is observed that Ec is dependent on extent of crystallization (α). Activation energy is also found to vary with atomic percentage of In in ternary Se80-xTe20Inx glassy system. The compositional dependence of Ec shows a re-versal in the trend at x = 15 in Se80-xTe20Inx, which is explained in terms of mechanically stabilized structure at this composition.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"2 1","pages":"64-71"},"PeriodicalIF":0.0,"publicationDate":"2012-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70939903","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. Willander, O. Nur, M. Israr, A. Hamad, F. G. E. Desouky, M. A. Salem, I. Battisha
Nano-composite, perovskite Ba(1- x - y)Sr(x)TiFe(y)O3, denoted as (BSTFe) in powder form was derived via sol-gel (SG) method followed by sintering at fixed temperature 750℃ for one hour. The chemical composition, morphology and structure of the powder samples were investigated by using X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). The XRD characterization indicates formation of a cubic crystalline phase in the pure BST. A well defined perovskite phase with nano-crystallite sizes equal to about 34 nm was achieved from XRD for B10ST3F sample, while TEM study confirmed the obtained XRD results giving the following crystallite size value about 33.75 nm for the same sample. The dielectric A.C. conductivity was evaluated as a function of temperature and frequency ranging from 42 Hz up to 1 MHz.
采用溶胶-凝胶(SG)法制备了Ba(1- x - y)Sr(x) fe (y)O3纳米复合材料(BSTFe)，并在750℃固定温度下烧结1h。采用x射线衍射(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)对粉末样品的化学成分、形貌和结构进行了研究。XRD表征表明，在纯BST中形成立方晶相。对B10ST3F样品进行XRD分析，得到了一个清晰的钙钛矿相，其纳米晶尺寸约为34 nm, TEM研究证实了所得XRD结果，得出了相同样品的晶尺寸约为33.75 nm。电介质交流电导率被评估为温度和频率范围从42 Hz到1 MHz的函数。
{"title":"Determination of A.C. Conductivity of Nano-Composite Perovskite Ba(1- x - y)Sr(x)TiFe(y)O3 Prepared by the Sol-Gel Technique","authors":"M. Willander, O. Nur, M. Israr, A. Hamad, F. G. E. Desouky, M. A. Salem, I. Battisha","doi":"10.4236/JCPT.2012.21001","DOIUrl":"https://doi.org/10.4236/JCPT.2012.21001","url":null,"abstract":"Nano-composite, perovskite Ba(1- x - y)Sr(x)TiFe(y)O3, denoted as (BSTFe) in powder form was derived via sol-gel (SG) method followed by sintering at fixed temperature 750℃ for one hour. The chemical composition, morphology and structure of the powder samples were investigated by using X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). The XRD characterization indicates formation of a cubic crystalline phase in the pure BST. A well defined perovskite phase with nano-crystallite sizes equal to about 34 nm was achieved from XRD for B10ST3F sample, while TEM study confirmed the obtained XRD results giving the following crystallite size value about 33.75 nm for the same sample. The dielectric A.C. conductivity was evaluated as a function of temperature and frequency ranging from 42 Hz up to 1 MHz.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"02 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2012-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.4236/JCPT.2012.21001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940160","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}
At present there is no explanation of the nature of interface instability upon first order phase transitions. The well-known theory of concentration overcooling under directed crystallization of solutions and Mullins-Sekerka instability cannot account for the diversified liquid component redistribution during solid state transition. In [1-3], within the framework of the nonequilibrium mass transfer problem, it has been shown that there are regimes of the interface instability, which differ from the known ones [4-6]. Moreover, the instability theory of works [1-3] demonstrates a complete experimental agreement of the dependence of eutectic pattern period on interface velocity. However, it is difficult to explain interface instability within the framework of a general setting of the mass-transfer problem. This paper is de-voted to qualitative analysis of the phenomena that are responsible for interface instability. The phenomena are connected by a single equation. Qualitative analysis revealed a variety of different conditions responsible for instability of flat interface stationary movement upon phase transition. The type of instability depends on system parameters. It is important that interface instability in the asymptotic case of quasi-equilibrium problem setting is qualitatively different from interface instability in the case of nonequilibrium problem setting.
{"title":"Qualititative Analysis of Interface Behavior under First Phase Transition","authors":"A. Guskov","doi":"10.4236/JCPT.2012.21005","DOIUrl":"https://doi.org/10.4236/JCPT.2012.21005","url":null,"abstract":"At present there is no explanation of the nature of interface instability upon first order phase transitions. The well-known theory of concentration overcooling under directed crystallization of solutions and Mullins-Sekerka instability cannot account for the diversified liquid component redistribution during solid state transition. In [1-3], within the framework of the nonequilibrium mass transfer problem, it has been shown that there are regimes of the interface instability, which differ from the known ones [4-6]. Moreover, the instability theory of works [1-3] demonstrates a complete experimental agreement of the dependence of eutectic pattern period on interface velocity. However, it is difficult to explain interface instability within the framework of a general setting of the mass-transfer problem. This paper is de-voted to qualitative analysis of the phenomena that are responsible for interface instability. The phenomena are connected by a single equation. Qualitative analysis revealed a variety of different conditions responsible for instability of flat interface stationary movement upon phase transition. The type of instability depends on system parameters. It is important that interface instability in the asymptotic case of quasi-equilibrium problem setting is qualitatively different from interface instability in the case of nonequilibrium problem setting.","PeriodicalId":64440,"journal":{"name":"结晶过程及技术期刊(英文)","volume":"02 1","pages":"25-29"},"PeriodicalIF":0.0,"publicationDate":"2012-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70940307","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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