Pub Date : 1986-01-01DOI: 10.2109/JCERSJ1950.94.1092_842
H. Hasegawa, I. Yasui
Two fundamental methods have been used for X-ray structure analysis of amorphous materials, i.e., the intensity comparison method and radial distribution analysis. There is an opinion that Fourier conversion from raw intensity data to a radial distribution function (RDF) introduces some errors and a comparison on intensity curves is, therefore, more exact. The present calculations have indicated that an RDF obtained from an intensity curve can be exactly re-transformed to the original intensity curve, if the upper range of Fourier-integral is sufficiently high. This means that no information disappears or any other spurious information is not added in the process of transformation between intensity data and an RDF. On the other hand, direct calculation of intensity with the Debye equation inevitably introduces truncation errors, unless some approximations are used. When the comparison on intensity curves is requested, it is desirable to transform an RDF obtained from a structure model to an intensity curve. Some distortions introduced in RDFs are offset each other in an observed and calculated RDFs and usually need not to be considered in the pair function method. There is, however, another opinion that some distortions introduced in RDFs difuse the part of small atomic distances and a comparison in intensity curves is, therefore, necessary. The present calculations indicate that atomic pairs with small inter-atomic distances can be equally compared in RDFs as well as in intensity curves as for oxide, chalcogenide or halide glasses. In conclusion, the present calculations have proved that errors are not intermixed in transformation process between an intensity curve and an RDF and that the same level of assessment of the structural models is possible either in intensity curves or in RDFs, although the intensity comparison method by use of the Debye equation can not avoid the intermixture of truncation errors, unless some approximations are used.
{"title":"Features and Relationship between Some Methods of X-ray Diffraction Analysis for Amorphous Materials","authors":"H. Hasegawa, I. Yasui","doi":"10.2109/JCERSJ1950.94.1092_842","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1092_842","url":null,"abstract":"Two fundamental methods have been used for X-ray structure analysis of amorphous materials, i.e., the intensity comparison method and radial distribution analysis. There is an opinion that Fourier conversion from raw intensity data to a radial distribution function (RDF) introduces some errors and a comparison on intensity curves is, therefore, more exact. The present calculations have indicated that an RDF obtained from an intensity curve can be exactly re-transformed to the original intensity curve, if the upper range of Fourier-integral is sufficiently high. This means that no information disappears or any other spurious information is not added in the process of transformation between intensity data and an RDF. On the other hand, direct calculation of intensity with the Debye equation inevitably introduces truncation errors, unless some approximations are used. When the comparison on intensity curves is requested, it is desirable to transform an RDF obtained from a structure model to an intensity curve. Some distortions introduced in RDFs are offset each other in an observed and calculated RDFs and usually need not to be considered in the pair function method. There is, however, another opinion that some distortions introduced in RDFs difuse the part of small atomic distances and a comparison in intensity curves is, therefore, necessary. The present calculations indicate that atomic pairs with small inter-atomic distances can be equally compared in RDFs as well as in intensity curves as for oxide, chalcogenide or halide glasses. In conclusion, the present calculations have proved that errors are not intermixed in transformation process between an intensity curve and an RDF and that the same level of assessment of the structural models is possible either in intensity curves or in RDFs, although the intensity comparison method by use of the Debye equation can not avoid the intermixture of truncation errors, unless some approximations are used.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77968075","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 : 1986-01-01DOI: 10.2109/JCERSJ1950.94.1095_1177
N. Tamari, I. Kondo, S. Sodeoka, K. Ueno, Y. Toibana
Si3N4-SiC whisker composites with whisker content up to 30wt% were prepared by heating 1700° to 2000°C for 60min in 1MPa N2. Fully dense composites were obtained at 2000°C. The optimum content of sintering aids, Y2O3 plus La2O3, was 20 and 30mol% for the whisker content of 10 and 20wt% respectively. The room temperature bending strength were 596 and 560MPa for 10 and 20wt% additions of whisker, respectively. Moreover, these composites had strengths more than 80% of the room temperature value at 1300°C. Improvement in the strength was achieved by using sieved whisker.
{"title":"Sintering of Si3N4-SiC Whisker Composite","authors":"N. Tamari, I. Kondo, S. Sodeoka, K. Ueno, Y. Toibana","doi":"10.2109/JCERSJ1950.94.1095_1177","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1095_1177","url":null,"abstract":"Si3N4-SiC whisker composites with whisker content up to 30wt% were prepared by heating 1700° to 2000°C for 60min in 1MPa N2. Fully dense composites were obtained at 2000°C. The optimum content of sintering aids, Y2O3 plus La2O3, was 20 and 30mol% for the whisker content of 10 and 20wt% respectively. The room temperature bending strength were 596 and 560MPa for 10 and 20wt% additions of whisker, respectively. Moreover, these composites had strengths more than 80% of the room temperature value at 1300°C. Improvement in the strength was achieved by using sieved whisker.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75708109","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 : 1986-01-01DOI: 10.2109/JCERSJ1950.94.1094_1068
M. Kawamura, T. Ohtake, K. Uchida, K. Kamiya, F. Ikazaki
One t/d test plant facilities of the shaft kiln for calcination of coal ash pellets is designed and constructed. Experimental studies are carried out with this test plant to examine the relationship between reactor behavior and product properties and to clarify the technical problems of the shaft kiln necessary to attain the stable operation. It is found that the most important factor is smooth movement of the pellets supllied from the top of the kiln. Steady and smooth discharge of the pellets could be achieved by applying a forced discharger like a ram feeder. The maximum temperature level of the moving bed in the shaft kiln is governed by not only operational conditions but green pellet composition such as carbon and moisture content. The position of the maximum temperature is affected by an air flow rate as well as discharge rate. The calcined pellets are tested according to JIS A 5002 (Light-weight concrete for structure) and Anouncement No. 13 of Environmental Agency (Industrial Waste Disposal Regulation) and tested properties satisfy the specification and regulation values. Especially, the compressive concrete strength shows 550kgf/cm2 which is about 40% stronger than that of JIS value. Conceptual design of a 50t/d pilot plant and cost estimation of the developed process are performed based on the studies conducted up to now. In case of a 1000t/d plant, production cost is estimated under 3000yen/m3.
设计并建造了1座灰球团立窑t/d试验装置。在该试验装置上进行了试验研究,以检验反应器性能与产品性能之间的关系,并澄清立窑实现稳定运行所必需的技术问题。发现最重要的因素是从窑顶供给的球团的平稳运动。稳定和平稳的颗粒排放可以通过应用强制卸料器来实现。立窑中移动床的最高温度水平不仅受操作条件的影响,而且受绿色球团成分(如碳和水分含量)的影响。最高温度的位置受空气流速和排放速率的影响。煅烧球团根据JIS A 5002(结构用轻质混凝土)和环境局公告第13号(工业废物处理条例)进行测试,测试性能满足规范和法规值。特别是混凝土抗压强度达到550kgf/cm2,比JIS标准高40%左右。在已有研究的基础上,进行了50t/d中试装置的概念设计和所开发工艺的成本估算。如果是1000t/d的工厂,生产成本估计在3000日元/立方米以下。
{"title":"Development of Light-Weight Aggregate Production Process from Coal Ash with a Shaft Kiln (Part 3)","authors":"M. Kawamura, T. Ohtake, K. Uchida, K. Kamiya, F. Ikazaki","doi":"10.2109/JCERSJ1950.94.1094_1068","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1094_1068","url":null,"abstract":"One t/d test plant facilities of the shaft kiln for calcination of coal ash pellets is designed and constructed. Experimental studies are carried out with this test plant to examine the relationship between reactor behavior and product properties and to clarify the technical problems of the shaft kiln necessary to attain the stable operation. It is found that the most important factor is smooth movement of the pellets supllied from the top of the kiln. Steady and smooth discharge of the pellets could be achieved by applying a forced discharger like a ram feeder. The maximum temperature level of the moving bed in the shaft kiln is governed by not only operational conditions but green pellet composition such as carbon and moisture content. The position of the maximum temperature is affected by an air flow rate as well as discharge rate. The calcined pellets are tested according to JIS A 5002 (Light-weight concrete for structure) and Anouncement No. 13 of Environmental Agency (Industrial Waste Disposal Regulation) and tested properties satisfy the specification and regulation values. Especially, the compressive concrete strength shows 550kgf/cm2 which is about 40% stronger than that of JIS value. Conceptual design of a 50t/d pilot plant and cost estimation of the developed process are performed based on the studies conducted up to now. In case of a 1000t/d plant, production cost is estimated under 3000yen/m3.","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80463312","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 : 1986-01-01DOI: 10.2109/JCERSJ1950.94.1091_689
K. Kimura, H. Tateyama, O. Ishibashi, K. Jinnai
The correlation between temperature transforming into bloating of a formed sample and nominal temperature equivalent to its refractoriness in the JIS method was positive . This result suggested that refractoriness of Amakusa pottery stone is determined by thermal expansion curves . The various thermal expansion curves were measured under different conditions of milling time of samples , pellet thickress, forming pressure, heating rate and loading. Anomalous expansion due to bloating was observed, and the temperature (T5) giving a linear expansion coefficient of 5•~10-4cm/cm/•Ž was independent of the
{"title":"Determination of Refractoriness of Amakusa Pottery Stone by Thermal Expansion Curves","authors":"K. Kimura, H. Tateyama, O. Ishibashi, K. Jinnai","doi":"10.2109/JCERSJ1950.94.1091_689","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.94.1091_689","url":null,"abstract":"The correlation between temperature transforming into bloating of a formed sample and nominal temperature equivalent to its refractoriness in the JIS method was positive . This result suggested that refractoriness of Amakusa pottery stone is determined by thermal expansion curves . The various thermal expansion curves were measured under different conditions of milling time of samples , pellet thickress, forming pressure, heating rate and loading. Anomalous expansion due to bloating was observed, and the temperature (T5) giving a linear expansion coefficient of 5•~10-4cm/cm/•Ž was independent of the","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81541495","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 : 1985-01-01DOI: 10.2109/JCERSJ1950.93.1079_407
S. Kanzaki, T. Kumazawa, J. Asaumi, O. Abe, H. Tabata
On etudie les proprietes mecaniques de ceramiques de mullite en fonction de leur composition chimique a temperature ambiante et dans l'air a 1300°C. On note des differences significatives dans la resistance a la flexion et la tenacite quand la composition change
{"title":"Dependency of Mechanical Property of Sintered Mullite on Chemical Composition","authors":"S. Kanzaki, T. Kumazawa, J. Asaumi, O. Abe, H. Tabata","doi":"10.2109/JCERSJ1950.93.1079_407","DOIUrl":"https://doi.org/10.2109/JCERSJ1950.93.1079_407","url":null,"abstract":"On etudie les proprietes mecaniques de ceramiques de mullite en fonction de leur composition chimique a temperature ambiante et dans l'air a 1300°C. On note des differences significatives dans la resistance a la flexion et la tenacite quand la composition change","PeriodicalId":17274,"journal":{"name":"Journal of the Ceramic Association, Japan","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77997159","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}