Pub Date : 2012-08-21DOI: 10.1002/9781118472590.CH4
O. Sakamoto, C. Tanaka, S. Miyazaki, N. Shinohara, S. Ohkawa
{"title":"Application of The In‐Flight Melting Technology to an Alkaline Free Borosilicate Glass","authors":"O. Sakamoto, C. Tanaka, S. Miyazaki, N. Shinohara, S. Ohkawa","doi":"10.1002/9781118472590.CH4","DOIUrl":"https://doi.org/10.1002/9781118472590.CH4","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"3 1","pages":"45-49"},"PeriodicalIF":0.0,"publicationDate":"2012-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88309411","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 : 2012-08-21DOI: 10.1002/9781118472590.CH10
S. Kanehira, K. Hirao, T. Maruyama, Tsutomu Sawano
{"title":"Surface and Interface Modification of Silicate Glass via Supercritical Water","authors":"S. Kanehira, K. Hirao, T. Maruyama, Tsutomu Sawano","doi":"10.1002/9781118472590.CH10","DOIUrl":"https://doi.org/10.1002/9781118472590.CH10","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"41 1","pages":"91-96"},"PeriodicalIF":0.0,"publicationDate":"2012-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84211295","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 : 2012-04-30DOI: 10.1002/9781118405932.CH27
T. Haugan, M. Fowler, J. Tolliver, P. Barnes, W. Wong-Ng, L. Cook
{"title":"Flux Pinning and Properties of Solid‐Solution (Y,Nd)1+xBa2−xCu3O7−δ Superconductors","authors":"T. Haugan, M. Fowler, J. Tolliver, P. Barnes, W. Wong-Ng, L. Cook","doi":"10.1002/9781118405932.CH27","DOIUrl":"https://doi.org/10.1002/9781118405932.CH27","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"48 1","pages":"299-307"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82890838","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 : 2012-04-30DOI: 10.1002/9781118405932.CH15
N. Cheggour, J. Ekin, C. Clickner, R. Feenstra, A. Goyal, M. Paranthaman, N. Rutter
{"title":"Effect of Transverse Compressive Stress on Transport Critical Current Density of Y‐Ba‐Cu‐O Coated Ni and Ni‐W RABiTS Tapes","authors":"N. Cheggour, J. Ekin, C. Clickner, R. Feenstra, A. Goyal, M. Paranthaman, N. Rutter","doi":"10.1002/9781118405932.CH15","DOIUrl":"https://doi.org/10.1002/9781118405932.CH15","url":null,"abstract":"","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"62 1","pages":"157-170"},"PeriodicalIF":0.0,"publicationDate":"2012-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88845900","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 : 2012-04-25DOI: 10.1002/9781118407844.CH22
J. Provis, P. Duxson, G. C. Lukey, J. Deventer
A statistical thermodynamic model for the ordering of aluminum- and silicon-centered tetrahedra in the X-ray amorphous network structure of metakaolin-based geopolymers in the presence of different charge-balancing cations and mixtures of cations is presented. The model utilizes Gibbs energy minimization calculations, based on the energetic preference for Si-O-Al linkages over Si-O-Si and Al-O-Al, to calculate the concentrations of each type of bond. A random bond distribution is then applied to calculate the concentration of each possible tetrahedron coordination. The model output is compared with experimental 29 Si MAS NMR results, and found to predict the observed behavior satisfactorily. A correction to account for the presence of unreacted metakaolin in geopolymers is found to improve the model fit at low silica content. Next-nearest-neighbor effects are evident in deconvoluted NMR peak positions. The calculated energy penalty parameters closely match those obtained from the literature, and the trends in these parameters allow analysis of the effects of the different cations on geopolymerisation of metakaolin. The applicability of this model to geopolymeric systems indicates the potential for wider utilization in description of other amorphous aluminosilicate systems.
提出了在不同电荷平衡阳离子和混合阳离子存在下偏高岭土聚合物x射线非晶态网络结构中铝中心和硅中心四面体排序的统计热力学模型。该模型利用Gibbs能量最小化计算，基于Si-O-Al键相对于Si-O-Si和Al-O-Al键的能量偏好，来计算每种键的浓度。然后应用随机键分布来计算每个可能的四面体配位的浓度。将模型输出与实验的29 Si MAS NMR结果进行了比较，发现模型能令人满意地预测观察到的行为。对地聚合物中未反应偏高岭土的存在进行了修正，以改善低硅含量下的模型拟合。次近邻效应在反卷积核磁共振峰位置中很明显。计算得到的能量惩罚参数与文献中得到的参数非常吻合，这些参数的变化趋势可以用来分析不同阳离子对偏高岭土聚合的影响。该模型对地聚合物体系的适用性表明，在描述其他无定形硅酸铝体系方面具有更广泛的应用潜力。
{"title":"Modeling Si/Al Ordering in Metakaolin‐Based Geopolymers","authors":"J. Provis, P. Duxson, G. C. Lukey, J. Deventer","doi":"10.1002/9781118407844.CH22","DOIUrl":"https://doi.org/10.1002/9781118407844.CH22","url":null,"abstract":"A statistical thermodynamic model for the ordering of aluminum- and silicon-centered tetrahedra in the X-ray amorphous network structure of metakaolin-based geopolymers in the presence of different charge-balancing cations and mixtures of cations is presented. The model utilizes Gibbs energy minimization calculations, based on the energetic preference for Si-O-Al linkages over Si-O-Si and Al-O-Al, to calculate the concentrations of each type of bond. A random bond distribution is then applied to calculate the concentration of each possible tetrahedron coordination. The model output is compared with experimental 29 Si MAS NMR results, and found to predict the observed behavior satisfactorily. A correction to account for the presence of unreacted metakaolin in geopolymers is found to improve the model fit at low silica content. Next-nearest-neighbor effects are evident in deconvoluted NMR peak positions. The calculated energy penalty parameters closely match those obtained from the literature, and the trends in these parameters allow analysis of the effects of the different cations on geopolymerisation of metakaolin. The applicability of this model to geopolymeric systems indicates the potential for wider utilization in description of other amorphous aluminosilicate systems.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"17 1","pages":"245-252"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75408434","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 : 2012-04-25DOI: 10.1002/9781118408162.CH18
M. Pan, B. Bender
The giant dielectric constant of calcium copper titanate (CCTO) has attracted a lot of interests in the last few years. Its dielectric properties, however, appeared to be very sensitive to the processing conditions. In our recent experiments on the processing of CCTOs, we observed the frequent occurrence of microstructure with a bimodal grain size distribution and a correlation between dielectric constant and the percentage of large grains in bimodal CCTOs. In this study, we assumed that CCTO ceramics are barrier layer capacitors and proposed an analytical model to describe the dielectric behavior of CCTOs with a bimodal grain size distribution. More importantly, both the insulating layer and the conductive core were included in the model to describe the complex permittivity and hence relaxation in bimodal CCTOs.
{"title":"Complex Permittivity of Calcium Copper Titanate Ceramics with a Bimodal Grain Size Distribution","authors":"M. Pan, B. Bender","doi":"10.1002/9781118408162.CH18","DOIUrl":"https://doi.org/10.1002/9781118408162.CH18","url":null,"abstract":"The giant dielectric constant of calcium copper titanate (CCTO) has attracted a lot of interests in the last few years. Its dielectric properties, however, appeared to be very sensitive to the processing conditions. In our recent experiments on the processing of CCTOs, we observed the frequent occurrence of microstructure with a bimodal grain size distribution and a correlation between dielectric constant and the percentage of large grains in bimodal CCTOs. In this study, we assumed that CCTO ceramics are barrier layer capacitors and proposed an analytical model to describe the dielectric behavior of CCTOs with a bimodal grain size distribution. More importantly, both the insulating layer and the conductive core were included in the model to describe the complex permittivity and hence relaxation in bimodal CCTOs.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"3 1","pages":"165-172"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75622535","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 : 2012-04-25DOI: 10.1002/9781118407844.CH16
V. Srivastava
C/C-SiC composite is a fibre composite made of carbon fibre and a brittle ceramic matrix. This has the advantage to combine monolithic ceramic with a higher tolerance of damage and lower specific stress. Characteristically states of defects already arise during the production process, such as crack pattern, fable fibres / matrix bond, delamination and high porosity. Some of the defects are favoured in view of the damage tolerance necessary for the technical use, but make it difficult to evaluate the damage condition. The main advantage of carbon fibre reinforced silicon carbide (C/C-SiC) is the damage tolerant mechanical behaviour compared to monolithic ceramics. Fracture mechanics test were carried out on chevron notched bend specimens. The present study is aimed to qualitatively examine the damage surface of C/C-SiC composites by the use of Scanning Electron Microscope (SEM) with the change of impact load. For quality assurance reasons the development of micro crack pattern under different loading conditions was investigated. Low and high impact tests were performed on C/C-SiC composites before and after the conditioning at 1600°C temperature.
{"title":"Damage morphology of C/C-SiC composites under impact tests","authors":"V. Srivastava","doi":"10.1002/9781118407844.CH16","DOIUrl":"https://doi.org/10.1002/9781118407844.CH16","url":null,"abstract":"C/C-SiC composite is a fibre composite made of carbon fibre and a brittle ceramic matrix. This has the advantage to combine monolithic ceramic with a higher tolerance of damage and lower specific stress. Characteristically states of defects already arise during the production process, such as crack pattern, fable fibres / matrix bond, delamination and high porosity. Some of the defects are favoured in view of the damage tolerance necessary for the technical use, but make it difficult to evaluate the damage condition. The main advantage of carbon fibre reinforced silicon carbide (C/C-SiC) is the damage tolerant mechanical behaviour compared to monolithic ceramics. Fracture mechanics test were carried out on chevron notched bend specimens. The present study is aimed to qualitatively examine the damage surface of C/C-SiC composites by the use of Scanning Electron Microscope (SEM) with the change of impact load. For quality assurance reasons the development of micro crack pattern under different loading conditions was investigated. Low and high impact tests were performed on C/C-SiC composites before and after the conditioning at 1600°C temperature.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"9 1","pages":"181-187"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73037538","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 : 2012-04-25DOI: 10.1002/9781118407950.CH3
D. Peeler, A. Cozzi, R. Schumacher, I. Reamer, R. Workman
The Savannah River National Laboratory (SRNL) has developed a process to recover, decontaminate, and reuse Pd from a radioactive waste (referred to as Pd/K) resulting from the tritium production process. The feasibility of efficiently recovering Pd was demonstrated through a series of tests based on the use of a simple additive followed by thermal processing and mechanical separation. More specifically, 10 mole borax (Na 2 B 4 O 7 • 10H 2 O) was added to deuterium-cycled Pd/K material on a 1:1 mass basis and heated at 1575°C for 4 hours. The diatomaceous earth reacts with the borax to produce a borosilicate glass product. At temperature, the Pd melts and coalesces to form an ingot which settles to the bottom of the crucible due to density differences. After cooling, the glass can be mechanically fractured and the Pd ingot separated and recovered. Based on the initial weight of Pd/K material used, the weights of the recovered Pd ingots, and assuming the Pd/K was 40 - 50% Pd by weight, it was estimated that approximately 95 - 99% of the Pd was recovered. The recovered Pd was determined to be substantially free of deuterium after isotopic exchange with high purity protium meeting programmatic objectives.
{"title":"Recovery of Palladium VIA a Vitrification Process","authors":"D. Peeler, A. Cozzi, R. Schumacher, I. Reamer, R. Workman","doi":"10.1002/9781118407950.CH3","DOIUrl":"https://doi.org/10.1002/9781118407950.CH3","url":null,"abstract":"The Savannah River National Laboratory (SRNL) has developed a process to recover, decontaminate, and reuse Pd from a radioactive waste (referred to as Pd/K) resulting from the tritium production process. The feasibility of efficiently recovering Pd was demonstrated through a series of tests based on the use of a simple additive followed by thermal processing and mechanical separation. More specifically, 10 mole borax (Na 2 B 4 O 7 • 10H 2 O) was added to deuterium-cycled Pd/K material on a 1:1 mass basis and heated at 1575°C for 4 hours. The diatomaceous earth reacts with the borax to produce a borosilicate glass product. At temperature, the Pd melts and coalesces to form an ingot which settles to the bottom of the crucible due to density differences. After cooling, the glass can be mechanically fractured and the Pd ingot separated and recovered. Based on the initial weight of Pd/K material used, the weights of the recovered Pd ingots, and assuming the Pd/K was 40 - 50% Pd by weight, it was estimated that approximately 95 - 99% of the Pd was recovered. The recovered Pd was determined to be substantially free of deuterium after isotopic exchange with high purity protium meeting programmatic objectives.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"37 1","pages":"25-31"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78700286","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 : 2012-04-25DOI: 10.1002/9781118407950.CH6
M. Carter
Ceramic waste forms consisting mainly of Cr-, Ni-, Zn-, Mn-, Fe- or Co- substituted titanate hollandites to immobilise Cs-rich wastes are put forward. These are designed to be processed by melting in air at ∼1350°C. Alternate hot consolidation methods-sintering and hot isostatic pressing at ∼1250°C were investigated for the above as well as Al-, Ga-, and Mg-substituted titanate hollandite waste forms. Detailed characterisation electron microscopy is presented on all materials. The sintered and HIPed hollandite containing waste forms had normalised PCT Cs leachate concentrations of< 0.6 g/L.
{"title":"Hollandite‐Rich Ceramics for the Immobilisation of Cs","authors":"M. Carter","doi":"10.1002/9781118407950.CH6","DOIUrl":"https://doi.org/10.1002/9781118407950.CH6","url":null,"abstract":"Ceramic waste forms consisting mainly of Cr-, Ni-, Zn-, Mn-, Fe- or Co- substituted titanate hollandites to immobilise Cs-rich wastes are put forward. These are designed to be processed by melting in air at ∼1350°C. Alternate hot consolidation methods-sintering and hot isostatic pressing at ∼1250°C were investigated for the above as well as Al-, Ga-, and Mg-substituted titanate hollandite waste forms. Detailed characterisation electron microscopy is presented on all materials. The sintered and HIPed hollandite containing waste forms had normalised PCT Cs leachate concentrations of< 0.6 g/L.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"9 1","pages":"55-62"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78747975","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 : 2012-04-25DOI: 10.1002/9781118408162.CH9
R. Kukreja, Raj N. Singh
Carbonitride (C-N) thin films are deposited on Si (100) in a microwave plasma chemical vapor deposition system using CH4, H 2 and N 2 as precursor gases. Effects of deposition parameters such as microwave power, gas pressure, and flow rates of precursor gases on the films produced is studied. Raman spectroscopy, X-Ray diffraction, and scanning electron microscopy are used for characterization of these films. It is shown that the composition of films deposited depends on the starting precursor gas and pressure.
{"title":"Synthesis and Characterization of C‐N Thin Films Deposited on Si (100) Wafer by MPCVD","authors":"R. Kukreja, Raj N. Singh","doi":"10.1002/9781118408162.CH9","DOIUrl":"https://doi.org/10.1002/9781118408162.CH9","url":null,"abstract":"Carbonitride (C-N) thin films are deposited on Si (100) in a microwave plasma chemical vapor deposition system using CH4, H 2 and N 2 as precursor gases. Effects of deposition parameters such as microwave power, gas pressure, and flow rates of precursor gases on the films produced is studied. Raman spectroscopy, X-Ray diffraction, and scanning electron microscopy are used for characterization of these films. It is shown that the composition of films deposited depends on the starting precursor gas and pressure.","PeriodicalId":83360,"journal":{"name":"Transactions (English Ceramic Circle)","volume":"4 1","pages":"89-94"},"PeriodicalIF":0.0,"publicationDate":"2012-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74956014","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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