Y. Otsuki, Takashi Umeda, Ryoichi Tsunori, Masayuki Shinohara
Viscoelastic simulations of deformation-induced bubble coalescence in forming process under isothermal condition were carried out. Multi mode PTT model was used in a simplified model for deformation of Polypropylene(PP) melt between bubbles in plane strain. 2-Dimentional Lagrangian FEM was adopted in the unsteady creeping flow simulation. The numerical results demonstrates that the thinnest part between neighboring gas bubbles is easily deformable and consequently coalescence occurs. Still more, creep recovery by elastic residual stress promotes the coalescence. The strain-hardening property is very effective to the coalescence prevention. Furthermore, the relaxation time distribution of polymer melts has significant influence on the behavior. Composition of the relaxation time that is a little longer than the elongational time makes a deformed bubble unstable and causes bubbles to coalesce. The numerical simulation could explain the deference in appearances of foamed sheets made of various PP.
{"title":"Viscoelastic Simulation of Deformation-Induced Bubble Coalescence in Foaming Process","authors":"Y. Otsuki, Takashi Umeda, Ryoichi Tsunori, Masayuki Shinohara","doi":"10.1678/RHEOLOGY.33.9","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.33.9","url":null,"abstract":"Viscoelastic simulations of deformation-induced bubble coalescence in forming process under isothermal condition were carried out. Multi mode PTT model was used in a simplified model for deformation of Polypropylene(PP) melt between bubbles in plane strain. 2-Dimentional Lagrangian FEM was adopted in the unsteady creeping flow simulation. The numerical results demonstrates that the thinnest part between neighboring gas bubbles is easily deformable and consequently coalescence occurs. Still more, creep recovery by elastic residual stress promotes the coalescence. The strain-hardening property is very effective to the coalescence prevention. Furthermore, the relaxation time distribution of polymer melts has significant influence on the behavior. Composition of the relaxation time that is a little longer than the elongational time makes a deformed bubble unstable and causes bubbles to coalesce. The numerical simulation could explain the deference in appearances of foamed sheets made of various PP.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"288 1","pages":"9-16"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76634294","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}
Consistent thickening sol-style food samples having hardness equivalent to salad oil and plain yoghurt, respectively, were prepared with the use of thickening agents made of mixing starch and guar gum in various composition ratios. The correlation between the viscoelastic behavior of these samples and such sensory values as "ease of swallowing" was studied. An effective way of assessing the "in-mouth sensation" and "ease of swallowing" of these consistent sol-style food samples was to examine the tan δ of the dynamic viscoelasticity of the sample in the linear region, as well as the distortion dependence and, in particular, to study the torque and attenuation status of G' in the non-linear region. The "ease of swallowing" of the samples can be estimated to a certain extent from the G' and tan δ on the low frequency side.
{"title":"Viscoelastic Behavior and Sensory Evaluation of Thickening Sol-Style Foods Prepared with the Use of Thickening Agents Made of Mixed Starch-Guar Gum","authors":"Tomoko Takahashi, Aki Kawano, H. Ogoshi","doi":"10.1678/RHEOLOGY.33.87","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.33.87","url":null,"abstract":"Consistent thickening sol-style food samples having hardness equivalent to salad oil and plain yoghurt, respectively, were prepared with the use of thickening agents made of mixing starch and guar gum in various composition ratios. The correlation between the viscoelastic behavior of these samples and such sensory values as \"ease of swallowing\" was studied. An effective way of assessing the \"in-mouth sensation\" and \"ease of swallowing\" of these consistent sol-style food samples was to examine the tan δ of the dynamic viscoelasticity of the sample in the linear region, as well as the distortion dependence and, in particular, to study the torque and attenuation status of G' in the non-linear region. The \"ease of swallowing\" of the samples can be estimated to a certain extent from the G' and tan δ on the low frequency side.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"2006 1","pages":"87-92"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83043583","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}
This study concerns crystallization behavior of crystalline polymers in a phase-separated polymer blend. It might be generally considered that spherulites cannot grow bigger than phase-separated domains. However, it has been confirmed experimentally that it is possible. We found that the same phenomena for blends of LLDPE (linear low density polyethylene) with a rubber polymer. In this study, effects of phase-separated domains on the spherulite growth and the crystallization behavior of LLDPE were studied. For quantitative discussion, we employed a simultaneous measurement technique of synchrotron SAXS/WAXS/Hv-SALS. It was found that the spherulites were 10~20 times lager than the phase-separated domains. It was also found that the long period of crystalline lamellae was smaller than phase-separated domains. Therefore, we suppose that the phase-separated structure has no influence on the fibril growth, which is the fundamental step of spherulites growth. Namely, the fibril growth through a channel of phase-separated crystalline domains enables the overall growth of spherulites. In the meantime, it was found that the index of degree of crystallinity in the LLDPE phase decreased slightly with the blend composition and induction periods of SAXS, WAXS, Hv-SALS in the phase-sepatared blend of LLDPE with a rubbery polymer were longer than those in a neat LLDPE. It was also suggested that nuclear growth was obstructed to some extent by the phase-separated domains. We suppose that nuclei which were not obstructed grew so that spherulites in the phase-sepatared blend sample became bigger than in a neat LLDPE sample.
{"title":"小角・広角X線散乱／Hv光散乱同時測定による直鎖状低密度ポリエチレン／ゴムブレンド中での結晶化挙動の解析","authors":"京子 林, 靖和 江島, 武史 清水, 木崎 寿美子, 滋郎 原, 勝廣 山本, 茂 岡本, 伸一 櫻井","doi":"10.1678/RHEOLOGY.32.179","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.179","url":null,"abstract":"This study concerns crystallization behavior of crystalline polymers in a phase-separated polymer blend. It might be generally considered that spherulites cannot grow bigger than phase-separated domains. However, it has been confirmed experimentally that it is possible. We found that the same phenomena for blends of LLDPE (linear low density polyethylene) with a rubber polymer. In this study, effects of phase-separated domains on the spherulite growth and the crystallization behavior of LLDPE were studied. For quantitative discussion, we employed a simultaneous measurement technique of synchrotron SAXS/WAXS/Hv-SALS. It was found that the spherulites were 10~20 times lager than the phase-separated domains. It was also found that the long period of crystalline lamellae was smaller than phase-separated domains. Therefore, we suppose that the phase-separated structure has no influence on the fibril growth, which is the fundamental step of spherulites growth. Namely, the fibril growth through a channel of phase-separated crystalline domains enables the overall growth of spherulites. In the meantime, it was found that the index of degree of crystallinity in the LLDPE phase decreased slightly with the blend composition and induction periods of SAXS, WAXS, Hv-SALS in the phase-sepatared blend of LLDPE with a rubbery polymer were longer than those in a neat LLDPE. It was also suggested that nuclear growth was obstructed to some extent by the phase-separated domains. We suppose that nuclei which were not obstructed grew so that spherulites in the phase-sepatared blend sample became bigger than in a neat LLDPE sample.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"31 1","pages":"179-187"},"PeriodicalIF":0.0,"publicationDate":"2004-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86652443","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 role of ion aggregates in EMAA ionomers on elongational viscosities under uniaxial, biaxial and planar was investigated. Firstly, measurement technique of biaxial and planar elongational viscosities for EMAA ionomers can be optimized due to its difficulties. After optimization, uniaxial, biaxial and planar elongational viscosities of ionomers were obtained. It was considered that effects of ion aggregates can not be appeared under uniaxial deformation in all of strain rates region. On the other hand, it was found that behavior of ion aggregates was changed under biaxial and planar deformations. It was considered that behavior of ion aggregates may be changed by two factors, deformation type and degree of strain rates.
{"title":"エチレン系アイオノマーの一軸，二軸，平面伸長粘度特性","authors":"昭博 西岡, 西尾 美帆子, 辰宏 高橋, 清人 小山","doi":"10.1678/RHEOLOGY.32.65","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.65","url":null,"abstract":"The role of ion aggregates in EMAA ionomers on elongational viscosities under uniaxial, biaxial and planar was investigated. Firstly, measurement technique of biaxial and planar elongational viscosities for EMAA ionomers can be optimized due to its difficulties. After optimization, uniaxial, biaxial and planar elongational viscosities of ionomers were obtained. It was considered that effects of ion aggregates can not be appeared under uniaxial deformation in all of strain rates region. On the other hand, it was found that behavior of ion aggregates was changed under biaxial and planar deformations. It was considered that behavior of ion aggregates may be changed by two factors, deformation type and degree of strain rates.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"69 1","pages":"65-69"},"PeriodicalIF":0.0,"publicationDate":"2004-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83543585","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}
Influence of surface treatment and crosslinking density on the rheological and mechanical properties of silicone resin filled with silica particles was investigated. Although addition of particle in the liquid silicone matrix increased the storage modulus G' and the complex viscosity |η*| especially at a low frequency region, surface treatment of particle suppressed such tendency. On the other hand, surface treatment increased the storage modulus E' and the tensile modulus E of crosslinked elastomers. Particle unfilled silicone elastomer showed an increasing storage modulus with temperature at a rubbery region behaving as an entropy elastomer and highly particle filled elastomers showed a decreasing storage modulus indicating an enthalpy elastic character. However silicone elastomers with small particle content changed their character from entropy elastic to enthalpy elastic with increasing crosslinking density.
{"title":"Influence of Surface Treatment and Crosslinking Density on the Rheological and Mechanical Properties of Particle Filled Elastomers","authors":"Kazuyuki Shohara, K. Uotani, H. Yamane","doi":"10.1678/RHEOLOGY.32.79","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.79","url":null,"abstract":"Influence of surface treatment and crosslinking density on the rheological and mechanical properties of silicone resin filled with silica particles was investigated. Although addition of particle in the liquid silicone matrix increased the storage modulus G' and the complex viscosity |η*| especially at a low frequency region, surface treatment of particle suppressed such tendency. On the other hand, surface treatment increased the storage modulus E' and the tensile modulus E of crosslinked elastomers. Particle unfilled silicone elastomer showed an increasing storage modulus with temperature at a rubbery region behaving as an entropy elastomer and highly particle filled elastomers showed a decreasing storage modulus indicating an enthalpy elastic character. However silicone elastomers with small particle content changed their character from entropy elastic to enthalpy elastic with increasing crosslinking density.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"17 1","pages":"79-84"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81749483","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}
Theoretical study of the rheology of soft materials is reviewed, especially the stress diffusion coupling of gels under stress is discussed.
综述了软质材料流变学的理论研究，重点讨论了凝胶在应力作用下的应力扩散耦合。
{"title":"Theoretical Study of the Rheology of Soft Materials","authors":"M. Doi","doi":"10.1678/RHEOLOGY.32.11","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.11","url":null,"abstract":"Theoretical study of the rheology of soft materials is reviewed, especially the stress diffusion coupling of gels under stress is discussed.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"125 1","pages":"11-16"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90385480","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}
This paper presents our three studies: (1) dynamic heterogeneity in miscible polymer blends, (2) dielectric study on the dynamics of flexible polymer chains in melts and solutions, and (3) stress relaxation of entangled polymer systems in biaxial extension. In the study of (1), we investigated the segmental and global dynamics mainly in miscible polyisoprene (PI) / poly(vinyl ethylene) (PVE) blends. Specifically, we estimated the characteristic sizes of the segmental motion. Furthermore, in order to see the effect of the concentration fluctuation (CF) on the segmental dynamics, we compared the dielectric relaxation spectra of the segmental motion between PI/PVE blend and PI-PVE diblock copolymer based on the fact that the CF amplitude is suppressed in the diblock copolymer system. In the second study, dipole inverted type-A polymers are used to investigate the detailed chain dynamics. In the third study, we determined the damping function in biaxial extensional deformation for polystyrene melts and compared with Doi-Edwards theory.
{"title":"Studies on Dynamic Heterogeneity in Miscible Polymer Blends and Dynamics of Flexible Polymers","authors":"O. Urakawa","doi":"10.1678/RHEOLOGY.32.265","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.265","url":null,"abstract":"This paper presents our three studies: (1) dynamic heterogeneity in miscible polymer blends, (2) dielectric study on the dynamics of flexible polymer chains in melts and solutions, and (3) stress relaxation of entangled polymer systems in biaxial extension. In the study of (1), we investigated the segmental and global dynamics mainly in miscible polyisoprene (PI) / poly(vinyl ethylene) (PVE) blends. Specifically, we estimated the characteristic sizes of the segmental motion. Furthermore, in order to see the effect of the concentration fluctuation (CF) on the segmental dynamics, we compared the dielectric relaxation spectra of the segmental motion between PI/PVE blend and PI-PVE diblock copolymer based on the fact that the CF amplitude is suppressed in the diblock copolymer system. In the second study, dipole inverted type-A polymers are used to investigate the detailed chain dynamics. In the third study, we determined the damping function in biaxial extensional deformation for polystyrene melts and compared with Doi-Edwards theory.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"48 1","pages":"265-270"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85984976","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. Miyahara, S. Ooi, Katsuya Nakaishi, Motoyoshi Kobayashi, Y. Adachi
A flow model consisting of a clear annulus of the suspending layer surrounding a core of the suspension has been proposed for the flow of colloidal suspensions through a capillary tube. In the present study, on the basis of this model, we derived apparent viscosity equations by considering the effects of the slip along the wall of tube and the floc breakup due to shear stress for a coagulated region. The validity of the derived equation was confirmed as follows. For the dispersed region, the derived equation was applied to the experimental data measured by previous authors, in which the apparent viscosity of suspensions of rigid spheres decreased with decreasing capillary diameter. For the coagulated region, the equation was applied to the experimental results obtained by the measurement of apparent viscosity of a montmorillonite suspension. The apparent viscosity decreased with increasing capillary diameter in a region of low electrolyte concentration (0.3, 0.45mol/L NaCl). On the other hand, viscosity decreased with decreasing diameter in a region of high electrolyte concentration (0.8, 1.0mol/L NaCl).
{"title":"Capillary Diameter Effects on the Apparent Viscosity of the Suspension of Clay Flocs","authors":"K. Miyahara, S. Ooi, Katsuya Nakaishi, Motoyoshi Kobayashi, Y. Adachi","doi":"10.1678/RHEOLOGY.32.277","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.277","url":null,"abstract":"A flow model consisting of a clear annulus of the suspending layer surrounding a core of the suspension has been proposed for the flow of colloidal suspensions through a capillary tube. In the present study, on the basis of this model, we derived apparent viscosity equations by considering the effects of the slip along the wall of tube and the floc breakup due to shear stress for a coagulated region. The validity of the derived equation was confirmed as follows. For the dispersed region, the derived equation was applied to the experimental data measured by previous authors, in which the apparent viscosity of suspensions of rigid spheres decreased with decreasing capillary diameter. For the coagulated region, the equation was applied to the experimental results obtained by the measurement of apparent viscosity of a montmorillonite suspension. The apparent viscosity decreased with increasing capillary diameter in a region of low electrolyte concentration (0.3, 0.45mol/L NaCl). On the other hand, viscosity decreased with decreasing diameter in a region of high electrolyte concentration (0.8, 1.0mol/L NaCl).","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"9 1","pages":"277-284"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87494711","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. Inoue, I. Fukawa, U. Ryu, S. Takenaka, J. Furusho
Asahi KASEI group developed two types of ER fluid and succeeded in employing them to practical applications. A homogeneous type consisting of liquid crystalline polysiloxane and a diluent was used for an intelligent brake in a caster walker which prevents a patient from stumbling. A heterogeneous (particle dispersion) type was used for a clutch in an upper limb training system with 3D movements and 3D vision. Key points for employing ER fluids in such devices with less trouble were introduced. The ER effect generation mechanisms of the homogeneous type fluids (type A and type B) were proposed.
{"title":"Development of New Types of ER Fluid and Their Practical Application to Care and Rehabilitation Machines","authors":"A. Inoue, I. Fukawa, U. Ryu, S. Takenaka, J. Furusho","doi":"10.1678/RHEOLOGY.32.253","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.253","url":null,"abstract":"Asahi KASEI group developed two types of ER fluid and succeeded in employing them to practical applications. A homogeneous type consisting of liquid crystalline polysiloxane and a diluent was used for an intelligent brake in a caster walker which prevents a patient from stumbling. A heterogeneous (particle dispersion) type was used for a clutch in an upper limb training system with 3D movements and 3D vision. Key points for employing ER fluids in such devices with less trouble were introduced. The ER effect generation mechanisms of the homogeneous type fluids (type A and type B) were proposed.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"22 1","pages":"253-258"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83254595","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}
Viscoelastic properties of several types of multi-component polymer systems were studied. For the miscible blends of poly(styrene-co-acrylonitrile) (SAN) with several (co)polymers, the time-temperature superposition principle was applicable over the entire temperature range and the relaxation behavior was similar to that of a blend consisting of homologous polymers. Poly(vinyl chloride) (PVC)/plasticizer systems exhibited a typical critical gel behavior by changing PVC concentration and temperature. For the carbon black (CB) suspensions, three different types of the rheological behavior were observed: highly nonlinear, elasto-plastic feature, sol-gel transition type behavior, and the slow relaxation due to Brownian diffusion, with the affinity of suspending medium toward the CB particles. Similarity between the behaviors of CB suspensions and ABS polymer melts is also discussed.
{"title":"Rheology of Multi-Component Polymer Systems","authors":"Y. Aoki","doi":"10.1678/RHEOLOGY.32.235","DOIUrl":"https://doi.org/10.1678/RHEOLOGY.32.235","url":null,"abstract":"Viscoelastic properties of several types of multi-component polymer systems were studied. For the miscible blends of poly(styrene-co-acrylonitrile) (SAN) with several (co)polymers, the time-temperature superposition principle was applicable over the entire temperature range and the relaxation behavior was similar to that of a blend consisting of homologous polymers. Poly(vinyl chloride) (PVC)/plasticizer systems exhibited a typical critical gel behavior by changing PVC concentration and temperature. For the carbon black (CB) suspensions, three different types of the rheological behavior were observed: highly nonlinear, elasto-plastic feature, sol-gel transition type behavior, and the slow relaxation due to Brownian diffusion, with the affinity of suspending medium toward the CB particles. Similarity between the behaviors of CB suspensions and ABS polymer melts is also discussed.","PeriodicalId":17434,"journal":{"name":"Journal of the Society of Rheology, Japan","volume":"11 1","pages":"235-243"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86470698","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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