Pinning properties were investigated for bulk Y-123 superconductors in an underdoped condition by heat treatment at a high temperature. The critical current density was drastically decreased. It is ascribed to the weakened pinning strength of 211 phase particles resulting from a degradation of the superconductivity in the block layer. A decrease of g2, the number of flux lines in the flux bundle, was found to be stronger than that of the pinning strength. This indicates that an additional disorder because of the thermal activation of flux lines also makes g2 smaller. The present result shows that the disorder transition that causes the peak effect is more strongly affected by the elastic properties than by the pinning strength.
{"title":"Effect of Deoxygenation on the Flux-Pinning Properties of Superconducting Y-123","authors":"D. Yoshimi, M. Migita, E. Otabe, T. Matsushita","doi":"10.2221/JCSJ.37.420","DOIUrl":"https://doi.org/10.2221/JCSJ.37.420","url":null,"abstract":"Pinning properties were investigated for bulk Y-123 superconductors in an underdoped condition by heat treatment at a high temperature. The critical current density was drastically decreased. It is ascribed to the weakened pinning strength of 211 phase particles resulting from a degradation of the superconductivity in the block layer. A decrease of g2, the number of flux lines in the flux bundle, was found to be stronger than that of the pinning strength. This indicates that an additional disorder because of the thermal activation of flux lines also makes g2 smaller. The present result shows that the disorder transition that causes the peak effect is more strongly affected by the elastic properties than by the pinning strength.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"420-426"},"PeriodicalIF":0.0,"publicationDate":"2002-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187548","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 new generation of high gradient magnetic separation (HGMS) has recently received attention again, especially for its applications in the fields of water and wastewater treatment. The reason for this attention is that a newly developed superconducting magnet can be used to easily generate a high magnetic field, under which even weakly paramagnetic materials can be separated at high efficiency. Furthermore, new magnetic seeding processes without the addition of magnetite have been developed for the separation of nonmagnetic particles from the viewpoint of colloid chemistry and material science. We also have developed a new wastewater treatment process that uses magnetic gel particles containing immobilized microorganisms and magnetic particles. The magnetic gel particles are magnetically separated and recovered from the effluent in wastewater treatment processes, and are then recycled to a bioreactor directly or reused after storing. In this paper, the applications of magnetic separation to the recovery of microorganisms for wastewater treatment use were reviewed. Further, a novel type of magnetic separator without a filter matrix was introduced to the continuous separation and recovery of magnetic gel particles with different magnetic characteristics.
{"title":"Magnetic Separation for the Recovery of Microorganisms in Wastewater Treatment","authors":"H. Ozaki, S. Kurinobu, T. Sumino","doi":"10.2221/JCSJ.37.404","DOIUrl":"https://doi.org/10.2221/JCSJ.37.404","url":null,"abstract":"A new generation of high gradient magnetic separation (HGMS) has recently received attention again, especially for its applications in the fields of water and wastewater treatment. The reason for this attention is that a newly developed superconducting magnet can be used to easily generate a high magnetic field, under which even weakly paramagnetic materials can be separated at high efficiency. Furthermore, new magnetic seeding processes without the addition of magnetite have been developed for the separation of nonmagnetic particles from the viewpoint of colloid chemistry and material science. We also have developed a new wastewater treatment process that uses magnetic gel particles containing immobilized microorganisms and magnetic particles. The magnetic gel particles are magnetically separated and recovered from the effluent in wastewater treatment processes, and are then recycled to a bioreactor directly or reused after storing. In this paper, the applications of magnetic separation to the recovery of microorganisms for wastewater treatment use were reviewed. Further, a novel type of magnetic separator without a filter matrix was introduced to the continuous separation and recovery of magnetic gel particles with different magnetic characteristics.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"404-409"},"PeriodicalIF":0.0,"publicationDate":"2002-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187508","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}
K. Shimohata, S. Yokoyama, T. Inaguchi, Shiro Nakamura, Yasuo Ozawa
Current distribution in the superconducting film for a resistive fault current limiter is important because it influences AC loss and a uniformity of S/N transition. The lateral current distribution of the film was reconstructed from the magnetic field distribution, which is measured by multiple Hall probes. The following results were obtained. (1) Non-uniform current distribution in the superconducting film was observed when the current was less than 1.3times critical current (Ic). (2) The current in a superconducting film was uniform when the current was much higher than Ic. The current can be considered uniform when the film works as a fault current limiter because the S/N transition starts at about twice Ic. (3) The validity of the measurement was verified by the comparison with the electric circuit simulation.
{"title":"Current Distribution Measurement of YBCO Thin Film for Superconducting Fault Current Limiter","authors":"K. Shimohata, S. Yokoyama, T. Inaguchi, Shiro Nakamura, Yasuo Ozawa","doi":"10.2221/JCSJ.37.410","DOIUrl":"https://doi.org/10.2221/JCSJ.37.410","url":null,"abstract":"Current distribution in the superconducting film for a resistive fault current limiter is important because it influences AC loss and a uniformity of S/N transition. The lateral current distribution of the film was reconstructed from the magnetic field distribution, which is measured by multiple Hall probes. The following results were obtained. (1) Non-uniform current distribution in the superconducting film was observed when the current was less than 1.3times critical current (Ic). (2) The current in a superconducting film was uniform when the current was much higher than Ic. The current can be considered uniform when the film works as a fault current limiter because the S/N transition starts at about twice Ic. (3) The validity of the measurement was verified by the comparison with the electric circuit simulation.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"410-415"},"PeriodicalIF":0.0,"publicationDate":"2002-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187520","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}
Several samples of TbAlO3 and related magnetic materials were developed. These materials have large magnetic moment, and most of them exhibit the magnetic phase transition below 4K. The heat capacity of all samples has been measured with the adiabatic heat-pulse method. The dependence of the heat capacity on the preparation temperature has been studied. We discussed possibility of using these materials as regenerator materials in pulse tube refrigerator.
{"title":"Substitution Effect of Oxide Magnetic Materials for Regenerator","authors":"H. Ikeda, T. Koyano, Y. Matsubara, R. Yoshizaki","doi":"10.2221/JCSJ.37.416","DOIUrl":"https://doi.org/10.2221/JCSJ.37.416","url":null,"abstract":"Several samples of TbAlO3 and related magnetic materials were developed. These materials have large magnetic moment, and most of them exhibit the magnetic phase transition below 4K. The heat capacity of all samples has been measured with the adiabatic heat-pulse method. The dependence of the heat capacity on the preparation temperature has been studied. We discussed possibility of using these materials as regenerator materials in pulse tube refrigerator.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"416-419"},"PeriodicalIF":0.0,"publicationDate":"2002-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187538","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}
Magnetic seeding processes were reviewed and classified from the viewpoint of interface chemistry and colloid chemistry. The description of the fundamental chemical processes of magnetic seeding was made to relate the modern seeding processes to traditional ones, such as ferrite, coprecipitation and flocculation. The processes developed in 1970s were found to provide a clue to develop a new method of magnetic seeding processes.
{"title":"Magnetically Seeding Processes","authors":"S. Takeda","doi":"10.2221/JCSJ.37.315","DOIUrl":"https://doi.org/10.2221/JCSJ.37.315","url":null,"abstract":"Magnetic seeding processes were reviewed and classified from the viewpoint of interface chemistry and colloid chemistry. The description of the fundamental chemical processes of magnetic seeding was made to relate the modern seeding processes to traditional ones, such as ferrite, coprecipitation and flocculation. The processes developed in 1970s were found to provide a clue to develop a new method of magnetic seeding processes.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"315-320"},"PeriodicalIF":0.0,"publicationDate":"2002-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187753","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}
{"title":"Basic Study on Oil Separation from Oil-Contaminated Seawater by MHD Method","authors":"K. Nishigaki, M. Takeda, N. Tomomori, A. Iwata","doi":"10.2221/JCSJ.37.343","DOIUrl":"https://doi.org/10.2221/JCSJ.37.343","url":null,"abstract":"","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"343-349"},"PeriodicalIF":0.0,"publicationDate":"2002-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187381","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}
Magnetic separation is a method to separate and capture fine magnetic particles by the magnetic force acting on the particles in a gradient magnetic field. For the practical use of the magnetic separation, it is necessary to remove the captured particles from the separation area where the magnetic force is active. High gradient magnetic separation utilizes the high spatial magnetic field gradient generated in the matrix of fine ferromagnetic wires (filter matrix) magnetized by an applied magnetic field. In batch-type magnetic separation, the filter matrix is washed by water flushing and by reducing the applied magnetic field to remove the captured particles in the filter matrix. When the particle content in the slurry is large, the short cycle of the water flushing of the filter matrix results in a decrease in separation efficiency. The frequent interruption of the separation process for the flushing is a problem for the practical magnetic separator. Therefore, from the viewpoint of the practical application of magnetic separation, a continuous separation process without interruption for the flushing is useful. In this paper, recently developed magnetic separators for continuous process are reviewed, and their mechanism is explained.
{"title":"Magnetic Separation Method for Continuous Separation Process","authors":"S. Fukui","doi":"10.2221/JCSJ.37.321","DOIUrl":"https://doi.org/10.2221/JCSJ.37.321","url":null,"abstract":"Magnetic separation is a method to separate and capture fine magnetic particles by the magnetic force acting on the particles in a gradient magnetic field. For the practical use of the magnetic separation, it is necessary to remove the captured particles from the separation area where the magnetic force is active. High gradient magnetic separation utilizes the high spatial magnetic field gradient generated in the matrix of fine ferromagnetic wires (filter matrix) magnetized by an applied magnetic field. In batch-type magnetic separation, the filter matrix is washed by water flushing and by reducing the applied magnetic field to remove the captured particles in the filter matrix. When the particle content in the slurry is large, the short cycle of the water flushing of the filter matrix results in a decrease in separation efficiency. The frequent interruption of the separation process for the flushing is a problem for the practical magnetic separator. Therefore, from the viewpoint of the practical application of magnetic separation, a continuous separation process without interruption for the flushing is useful. In this paper, recently developed magnetic separators for continuous process are reviewed, and their mechanism is explained.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"321-327"},"PeriodicalIF":0.0,"publicationDate":"2002-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2221/JCSJ.37.321","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187767","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}
Synopsis: Recent progress in magnet technology has enabled the realization of economically and operationally favorable superconducting magnets. Consequently, this has made it possible to utilize high-intensity magnetic fields occupying a large volume with very small electric power consumption in much broader areas of science and technology than in the past. Magnetic separa tion is a promising application because it can separate (or purify) a large quantity of dilute sus pension at high speed; it is repeatedly usable, and is recognized as a secondary-waste-free tech nology that will contribute significantly to the preservation of global environment. This intro ductory article discusses some of the fundamental characteristics of magnetic separation and the recent R & D activities from the viewpoint of an industrial application of superconducting magnets.
{"title":"From Basic Research to Industrial Application of Superconducting Magnets in Magnetic Separation","authors":"T. Ohara","doi":"10.2221/JCSJ.37.303","DOIUrl":"https://doi.org/10.2221/JCSJ.37.303","url":null,"abstract":"Synopsis: Recent progress in magnet technology has enabled the realization of economically and operationally favorable superconducting magnets. Consequently, this has made it possible to utilize high-intensity magnetic fields occupying a large volume with very small electric power consumption in much broader areas of science and technology than in the past. Magnetic separa tion is a promising application because it can separate (or purify) a large quantity of dilute sus pension at high speed; it is repeatedly usable, and is recognized as a secondary-waste-free tech nology that will contribute significantly to the preservation of global environment. This intro ductory article discusses some of the fundamental characteristics of magnetic separation and the recent R & D activities from the viewpoint of an industrial application of superconducting magnets.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"303-314"},"PeriodicalIF":0.0,"publicationDate":"2002-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187744","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 abrasives have been recovered from the slurry wasted by the factory where the silicon wafers for solar batteries are processed. The separator has been designed and developed for a practical application of superconducting magnetic separation. The SiC abrasives to which iron fragments of the wire adhere were separated. The iron particles from the wire sawing machine were also separated. The abrasives were successfully separated, and the wasted slurry could be recovered.
{"title":"Recovery of Abrasives from Wasted Slurry by Superconducting High Gradient Magnet Separation","authors":"S. Horie, S. Nishijima, S. Takeda, A. Nakahira","doi":"10.2221/JCSJ.37.338","DOIUrl":"https://doi.org/10.2221/JCSJ.37.338","url":null,"abstract":"The abrasives have been recovered from the slurry wasted by the factory where the silicon wafers for solar batteries are processed. The separator has been designed and developed for a practical application of superconducting magnetic separation. The SiC abrasives to which iron fragments of the wire adhere were separated. The iron particles from the wire sawing machine were also separated. The abrasives were successfully separated, and the wasted slurry could be recovered.","PeriodicalId":93144,"journal":{"name":"Teion kogaku = Cryogenic engineering : [official journal of the Cryogenic Association of Japan]","volume":"37 1","pages":"338-342"},"PeriodicalIF":0.0,"publicationDate":"2002-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68187364","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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