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Hironori Kaji - One of the best experts on this subject based on the ideXlab platform.
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Distribution Ratio of carbon black in polyisobutyrene/polyisoprene rubber blends using high-resolution solid-state ^13C NMR
Polymer Journal, 2015Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:We attempted to estimate the Distribution Ratio of carbon black (CB) in blends of polyisobutyrene rubber and polyisoprene rubber using high-resolution solid-state ^13C nuclear magnetic resonance (NMR). Our NMR analysis revealed that, in polyisobutyrene rubber/polyisoprene rubber/CB composites, CB more easily distributes in polyisoprene rubber than in polyisobutyrene rubber. We found that more than 70% of CB is distributed into the polyisoprene rubber phase. The sum of the amounts of CB in both the polyisobutyrene rubber and polyisoprene rubber phases estimated by our method using ^13C NMR closely corresponds with the amount of CB originally added to the compound, verifying the validity of the NMR method. Further, we observed the Distribution of CB in polyisobutyrene/polyisoprene rubber blends using transmission electron microscopy and the Carbon-Black-Gel method, which can only be used for unvulcanized rubber blends, for comparison. The results obtained using these three methods show similar tendencies, which confirms the accuracy of this method of using ^13C NMR to determine CB Distribution in rubber blends. We establish the ^13C nuclear magnetic resonance (NMR) method as the best available method for the evaluation of carbon black (CB) Distribution in rubber blend. We find that the line widths of NMR peaks increase as CB contents increase. Using this phenomenon it is found that, in polyisobutyrene rubber (IIR)/polyisoprene rubber (IR)/CB composites, CB more easily distributes in IR than in IIR. And we can estimate that more than 70% of CB is distributed in to the IR phase, irrespective of CB content.
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characterization of carbon filler Distribution Ratio in polyisoprene polybutadiene rubber blends by high resolution solid state 13c nmr
Macromolecules, 2007Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:The Distribution Ratio of carbon black (CB) in a blend of polyisoprene rubber (IR) and polybutadiene rubber (BR) is characterized using high-resolution solid-state 13C NMR. The relationships between the line width of the polymer's resonance lines and CB contents are estimated for both the IR/CB and BR/CB composites from the dipolar decoupling/magic angle spinning (DD/MAS) 13C NMR spectra. For the IR/CB composite, the IR line width increases with the increasing CB content. A similar relationship is obtained between the BR line width and CB contents for the BR/CB composite. These relationships are used as calibRation curves. On the basis of these calibRation curves, the Distribution Ratio of CB in the IR/BR rubber blend is determined. It is found for the IR/BR/CB composite that the amount of CB in the BR phase is approximately twice as high as that of CB in the IR phase, irrespective of the CB content. The sum of the amounts of CB in both the IR and BR phases, determined from the above 13C NMR experiments, ...
Marina Kotani - One of the best experts on this subject based on the ideXlab platform.
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Distribution Ratio of carbon black in polyisobutyrene/polyisoprene rubber blends using high-resolution solid-state ^13C NMR
Polymer Journal, 2015Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:We attempted to estimate the Distribution Ratio of carbon black (CB) in blends of polyisobutyrene rubber and polyisoprene rubber using high-resolution solid-state ^13C nuclear magnetic resonance (NMR). Our NMR analysis revealed that, in polyisobutyrene rubber/polyisoprene rubber/CB composites, CB more easily distributes in polyisoprene rubber than in polyisobutyrene rubber. We found that more than 70% of CB is distributed into the polyisoprene rubber phase. The sum of the amounts of CB in both the polyisobutyrene rubber and polyisoprene rubber phases estimated by our method using ^13C NMR closely corresponds with the amount of CB originally added to the compound, verifying the validity of the NMR method. Further, we observed the Distribution of CB in polyisobutyrene/polyisoprene rubber blends using transmission electron microscopy and the Carbon-Black-Gel method, which can only be used for unvulcanized rubber blends, for comparison. The results obtained using these three methods show similar tendencies, which confirms the accuracy of this method of using ^13C NMR to determine CB Distribution in rubber blends. We establish the ^13C nuclear magnetic resonance (NMR) method as the best available method for the evaluation of carbon black (CB) Distribution in rubber blend. We find that the line widths of NMR peaks increase as CB contents increase. Using this phenomenon it is found that, in polyisobutyrene rubber (IIR)/polyisoprene rubber (IR)/CB composites, CB more easily distributes in IR than in IIR. And we can estimate that more than 70% of CB is distributed in to the IR phase, irrespective of CB content.
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characterization of carbon filler Distribution Ratio in polyisoprene polybutadiene rubber blends by high resolution solid state 13c nmr
Macromolecules, 2007Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:The Distribution Ratio of carbon black (CB) in a blend of polyisoprene rubber (IR) and polybutadiene rubber (BR) is characterized using high-resolution solid-state 13C NMR. The relationships between the line width of the polymer's resonance lines and CB contents are estimated for both the IR/CB and BR/CB composites from the dipolar decoupling/magic angle spinning (DD/MAS) 13C NMR spectra. For the IR/CB composite, the IR line width increases with the increasing CB content. A similar relationship is obtained between the BR line width and CB contents for the BR/CB composite. These relationships are used as calibRation curves. On the basis of these calibRation curves, the Distribution Ratio of CB in the IR/BR rubber blend is determined. It is found for the IR/BR/CB composite that the amount of CB in the BR phase is approximately twice as high as that of CB in the IR phase, irrespective of the CB content. The sum of the amounts of CB in both the IR and BR phases, determined from the above 13C NMR experiments, ...
Young-mook Yun - One of the best experts on this subject based on the ideXlab platform.
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An Indeterminate Strut-Tie Model and Load Distribution Ratio for Reinforced Concrete Corbels
Journal of the Korean Society of Civil Engineers, 2014Co-Authors: Hyun-soo Chae, Young-mook YunAbstract:ABSTRACTThe ultimate behavior of reinforced concrete corbel is complicated due to the primary design variables including the shear span-to-effective depth Ratio a/d, flexural reinforcement Ratio, load condition, and material properties. In this study, a simple indeterminate strut-tie model reflecting all characteristics of the ultimate strength and complicated structural behavior is pr oposed for the design of the reinforced concrete corbels with shear span-to-effective depth Ratio of a/d ≤ 1. A load Distribution Ratio, defined as the fraction of applied load transferred by horizontal truss mechanism, is also proposed to help structural designers perform t he design of reinforced concrete corbels by using the strut-tie model approaches of current design codes. For the development of the load Distribution Ratio, numerous material nonlinear finite element analyses of the proposed indeterminate strut-tie model were cond ucted by changing primary design variables. The ultimate strengths of reinforced concrete corbels tested to failure were evaluated by incorporating the proposed strut-tie model and load Distribution Ratio into the ACI 318-11‘s strut-tie model method. The validi ty of the proposed model and load Distribution Ratio was examined by comparing the strength analysis results with those by the ACI 318-11 ‘sconventional design method and strut-tie model methods of current design codes. Key words : Reinforced concrete, Corbel, Strut-tie model, Load Distribution Ratio초 록철근콘크리트 코벨의 파괴거동은 코벨의 전단경간비 및 주인장 철근비를 포함한 여러 변수들로 인해 복잡하다 . 이 논문에서는 철근콘크리트 코벨의 강도 및 거동 특성을 논리적이고 합리적인 방법으로 반영하여 전단경간비가 1.0 이하인 철근콘크리트 코벨을 설계할 수 있는 단순한 형태의 1차 부정정 트러스 구조의 스트럿-타이 모델을 제안하였다. 또한 부정정 스트럿-타이 모델을 정정 트러스 구조의 스트럿-타이 모델로 변환시켜 현행 스트럿-타이 모델 설계기준에 의한 코벨의 설계를 가능하게 하는 하중분배율을 제안하였다 . 하중분배율 결정 시 스트럿과 타이의 재료적 비선형 거동을 고려할 수 있는 부정정 스트럿-타이 모델의 비탄성 구조해석을 통해 철근콘크리트 코벨의 강도 및 거동을 지배하는 전단경간비, 주인장 철근비, 수직하중에 대한 수평하중의 비, 그리고 콘크리트의 압축강도 등의 주요설계변수들의 영향을 반영하였다. 이 연구에서 제안한 부정정 스트럿-타이 모델 및 하중분배율의 적합성을 검증하기 위해 파괴실험이 수행된 다수의 철근콘크리트 코벨의 극한강도를 평가하였으며, 그 결과를 ACI 318-11의 전통적인 설계기준 및 정정 트러스 구조의 스트럿-타이 모델을 기반으로 하는 현행 주요 설계기준의 스트럿 -타이 모델 방법에 의한 평가결과와 비교분석하였다.검색어 : 철근콘크리트, 코벨, 스트럿-타이 모델, 하중분배율 Concrete Engineering
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Indeterminate Strut-Tie Model and Load Distribution Ratio of Continuous RC Deep Beams (I) Proposal of Model ＆ Load Distribution Ratio
Journal of the Korea Concrete Institute, 2011Co-Authors: Byung-hun Kim, Hyun-soo Chae, Young-mook YunAbstract:The structural behavior of continuous reinforced concrete deep beams is mainly controlled by the mechanical relationships associated with the shear span-to-effective depth Ratio, flexural reinforcement Ratio, load and support conditions, and material properties. In this study, a simple indeterminate strut-tie model which reflects characteristics of the complicated structural behavior of the continuous deep beams is presented. In addition, the reaction and load Distribution Ratios defined as the fraction of load carried by an exterior support of continuous deep beam and the fraction of load transferred by a vertical truss mechanism, respectively, are proposed to help structural designers for the analysis and design of continuous reinforced concrete deep beams by using the strut-tie model approaches of current design codes. In the determination of the load Distribution Ratio, a concept of balanced shear reinforcement Ratio requiring a simultaneous failure of inclined concrete strut and vertical steel tie is introduced to ensure a ductile shear failure of reinforced concrete deep beams, and the primary design variables including the shear span-to-effective depth Ratio, flexural reinforcement Ratio, and concrete compressive strength are implemented after thorough parametric numerical analyses. In the companion paper, the validity of the presented model and load Distribution Ratio was examined by applying them in the evaluation of the ultimate strength of multiple continuous reinforced concrete deep beams, which were tested to failure.
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An Indeterminate Strut-Tie Model and Load Distribution Ratio for RC Deep Beams - (I) Model & Load Distribution Ratio
Advances in Structural Engineering, 2011Co-Authors: Byung-hun Kim, Young-mook YunAbstract:The ultimate strength of simply supported reinforced concrete deep beams is governed by the capacity of the shear resistance mechanism. The structural behavior of the deep beams is controlled mainly by the mechanical relationships between the primary design variables including shear span-to-effective depth Ratio, flexural reinforcement Ratio, and the compressive strength of concrete. In this study, a simple indeterminate strut-tie model which reflects all characteristics of the ultimate strength and behavior of the deep beams was presented. A load Distribution Ratio, defined as the fraction of load transferred by a truss mechanism, was also proposed to help structural designers perform the Rational design of deep beams by using the strut-tie model approaches of current design codes. In the determination of the load Distribution Ratio, a concept of balanced shear reinforcement Ratio which ensures the ductile shear design of the deep beams was introduced, and the effect of the primary design variables was r...
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An Indeterminate Strut-Tie Model and Load Distribution Ratio for RC Deep Beams- (II) Validity Evaluation
Advances in Structural Engineering, 2011Co-Authors: Byung-hun Kim, Young-mook YunAbstract:In this study, the ultimate strength of 234 simply supported reinforced concrete deep beams tested to shear failure was evaluated by the ACI 318M-08's struttie model approach implemented with the indeterminate strut-tie model and load Distribution Ratio of the companion paper. The ultimate strength of the deep beams was also estimated by using the experimental shear strength models, the theoretical shear strength models, and the current strut-tie model design codes. The validity of the presented indeterminate strut-tie model and load Distribution Ratio was examined through the comparison of the strength analysis results classified according to the primary design variables of shear span-to-effective depth Ratio, flexural reinforcement Ratio, and compressive strength of concrete. The present study associated with the indeterminate strut-tie model and load Distribution Ratio evaluated the ultimate strength of 234 deep beams fairly accurately compared with those by other approaches. In addition, the present a...
Satoru Yanabu - One of the best experts on this subject based on the ideXlab platform.
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Voltage Behavior of Vacuum Circuit Breaker in Case of Series Connected
25th International Symposium on Discharges and Electrical Insulation in Vacuum (Isdeiv 2012), 2012Co-Authors: Hiroki Anji, Satoru Yanabu, IeeeAbstract:The vacuum circuit breaker is used as the single-break, and investigation is not conducted so much about the multi-break vacuum circuit breaker at present. So, we are investigating multi-break interrupters performance and the relation between the post arc current and the voltage Distribution Ratio in the double-break vacuum circuit breaker. In first investigation, performances of single, double and triple-break vacuum interrupter are measured to reveal their characteristics. In the results, multi-break vacuum interrupter has better breakdown characteristics than single-break vacuum interrupter. In second investigation, the post arc current and the voltage Distribution Ratio were measured in order to clarify the relation between the post arc current and voltage Distribution Ratio. Experiments are measurement of the post arc current which flows into one vacuum interrupter, and measurement of the voltage Distribution Ratio and post arc current of a double-break vacuum circuit breaker. The results of investigation showed that the bias of voltage Distribution Ratio occurs when the post arc current value which flows into each vacuum interrupter in a double-break vacuum circuit breaker became imbalanced. In addition, it turned out that the post arc current of spiral electrode is very scattering as compared with axial magnetic field electrode. It turned out that it is better to use the axial magnetic field electrode for a double-break vacuum circuit breaker.
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Relationship Between the Voltage Distribution Ratio and the Post Arc Current in Double-Break Vacuum Circuit Breakers
Plasma Science, IEEE Transactions on, 2009Co-Authors: Masanori Sugita, Tetsuo Igarashi, Ezra P A Van Lanen, Hiroaki Kasuya, Yoshihiko Matsui, Shigemitsu Okabe, Satoru YanabuAbstract:In many cases, single-break vacuum circuit breakers are used as circuit breakers, and so the characteristics of double-break vacuum circuit breakers have not received sufficient attention. This report describes our investigations of the interruption characteristics of double-break vacuum circuit breakers. We have investigated and clarified the relationship between the voltage Distribution Ratio and the post arc current in double-break vacuum circuit breakers by measuring the post arc current in the single-break vacuum circuit breaker, the voltage Distribution Ratio, and the post arc current in double-break vacuum circuit breakers. Our investigation has shown that the post arc current scatter of the spiral contact is much larger than that of the axial magnetic field contact. This result shows that the bias of the voltage Distribution Ratio was caused by the imbalanced post arc current in each vacuum interrupter in the double-break vacuum circuit breaker. Therefore, we conclude that axial magnetic field contacts are suitable for double-break vacuum circuit breakers.
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Interruption characteristics of double-break vacuum circuit breakers
IEEE Transactions on Dielectrics and Electrical Insulation, 2008Co-Authors: Naotaka Ide, O Tanaka, Shuhei Kaneko, Shigemitsu Okabe, Satoru Yanabu, Yoshihiko MatsuiAbstract:Since the majority of vacuum circuit breakers in use are of the single-break variety, there have been few studies of double-break vacuum circuit breakers. This report describes our investigations of the interruption characteristics of the double-break vacuum circuit breaker. In this investigation, the post arc current and recovery voltage Distribution Ratio were measured in order to clarify the relationship between them. The results show that a bias of the voltage Distribution Ratio occurs when the post arc current value becomes imbalanced. In addition, the measurements of the post arc current for circuit breakers with spiral contacts are very scattered as compared with those with axial magnetic field contacts. Normally, the double-break vacuum circuit breaker consists of two contacts of the same type. However, when two spiral contacts are used, the scattering of post arc current causes a current imbalance. As a result, a bias of the voltage Distribution Ratio may occur. It appears to be preferable to use double-break vacuum circuit breakers with axial magnetic field contacts.
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The relations between the voltage Distribution Ratio and the post arc current in double-break vacuum circuit breakers
2008 23rd International Symposium on Discharges and Electrical Insulation in Vacuum, 2008Co-Authors: Masanori Sugita, Tetsuo Igarashi, Ezra P A Van Lanen, Hiroaki Kasuya, O Tanaka, Yoshihiko Matsui, Shigemitsu Okabe, G. Ueta, Satoru YanabuAbstract:In many cases, the vacuum circuit breaker is used as the single-break, and investigation is not conducted so much about the double-break vacuum circuit breaker. So, we are investigating the relation between the post arc current and the voltage Distribution Ratio in the double-break vacuum circuit breaker. In this investigation, the post arc current and the voltage Distribution Ratio were measured in order to clarify the relation between the post arc current and voltage Distribution Ratio. Experiments are measurement of the post arc current which flows into one vacuum interrupter, and measurement of the voltage Distribution Ratio and post arc current of a double-break vacuum circuit breaker. The results of investigation showed that the bias of voltage Distribution Ratio occurs when the post arc current value which flows into each vacuum interrupter in a double-break vacuum circuit breaker became imbalanced. In addition, it turned out that the post arc current of spiral electrode is very scattering as compared with axial magnetic field electrode. Therefore, it turned out that it is much to use the axial magnetic field electrode for a double-break vacuum circuit breaker.
Hideaki Kimura - One of the best experts on this subject based on the ideXlab platform.
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Distribution Ratio of carbon black in polyisobutyrene/polyisoprene rubber blends using high-resolution solid-state ^13C NMR
Polymer Journal, 2015Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:We attempted to estimate the Distribution Ratio of carbon black (CB) in blends of polyisobutyrene rubber and polyisoprene rubber using high-resolution solid-state ^13C nuclear magnetic resonance (NMR). Our NMR analysis revealed that, in polyisobutyrene rubber/polyisoprene rubber/CB composites, CB more easily distributes in polyisoprene rubber than in polyisobutyrene rubber. We found that more than 70% of CB is distributed into the polyisoprene rubber phase. The sum of the amounts of CB in both the polyisobutyrene rubber and polyisoprene rubber phases estimated by our method using ^13C NMR closely corresponds with the amount of CB originally added to the compound, verifying the validity of the NMR method. Further, we observed the Distribution of CB in polyisobutyrene/polyisoprene rubber blends using transmission electron microscopy and the Carbon-Black-Gel method, which can only be used for unvulcanized rubber blends, for comparison. The results obtained using these three methods show similar tendencies, which confirms the accuracy of this method of using ^13C NMR to determine CB Distribution in rubber blends. We establish the ^13C nuclear magnetic resonance (NMR) method as the best available method for the evaluation of carbon black (CB) Distribution in rubber blend. We find that the line widths of NMR peaks increase as CB contents increase. Using this phenomenon it is found that, in polyisobutyrene rubber (IIR)/polyisoprene rubber (IR)/CB composites, CB more easily distributes in IR than in IIR. And we can estimate that more than 70% of CB is distributed in to the IR phase, irrespective of CB content.
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characterization of carbon filler Distribution Ratio in polyisoprene polybutadiene rubber blends by high resolution solid state 13c nmr
Macromolecules, 2007Co-Authors: Marina Kotani, Hidehiko Dohi, Hideaki Kimura, Kiyoshige Muraoka, Hironori KajiAbstract:The Distribution Ratio of carbon black (CB) in a blend of polyisoprene rubber (IR) and polybutadiene rubber (BR) is characterized using high-resolution solid-state 13C NMR. The relationships between the line width of the polymer's resonance lines and CB contents are estimated for both the IR/CB and BR/CB composites from the dipolar decoupling/magic angle spinning (DD/MAS) 13C NMR spectra. For the IR/CB composite, the IR line width increases with the increasing CB content. A similar relationship is obtained between the BR line width and CB contents for the BR/CB composite. These relationships are used as calibRation curves. On the basis of these calibRation curves, the Distribution Ratio of CB in the IR/BR rubber blend is determined. It is found for the IR/BR/CB composite that the amount of CB in the BR phase is approximately twice as high as that of CB in the IR phase, irrespective of the CB content. The sum of the amounts of CB in both the IR and BR phases, determined from the above 13C NMR experiments, ...