Researchers Database
KITSUNEZAKI So
| ■Faculty | Faculty Division of Natural Sciences Research Group of Physics | |||
| ■Position | Professor | |||
Last Updated :2024/04/15
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Profile and Settings
Name (Japanese)
KitsunezakiName (Kana)
So
Degree
Research Interests
- 微生物の集団運動
- 破壊力学
- 粉体の物理学
- パターン形成
- 非線形動力学
- Collective Motion of Microorganisms.
- Fracture Dynamics
- Physics of Granular Matter
- Pattern Formation
- Nonlinear Dynamics
Research Areas
Research Experience
- 2010, 2012, :奈良女子大学大学院人間文化研究科准教授
- 2010, 2012, :Associate prof., Graduate School of Human Culture, Nara Women's University
- 2012, -:奈良女子大学研究院自然科学系准教授
- 2012, -:Associate prof., Division of Natural Sciences, Faculty of Nara Women's University
- 2007, 2010, :奈良女子大学大学院人間文化研究科助教
- 2007, 2010, :Assistant prof., Graduate School of Human Culture, Nara Women's University
- 2001, 2007, :奈良女子大学大学院人間文化研究科助手
- 2001, 2007, :Assistant prof., Graduate School of Human Culture, Nara Women's University
- 1997, 2001, :奈良女子大学理学部助手
- 1997, 2001, :Assistant prof., Faculty of Science, Nara Women's University
Education
- 1997, Kyoto University, 理学研究科, 物理学第一, Japan
- 1997, Kyoto University, Graduate School, Division of Natural Science, Department of Physics
- 1992, Kyoto University, Faculty of Science, Japan
- 1992, Kyoto University, Faculty of Science
Association Memberships
Ⅱ．研究活動実績
Published Papers
- Refereed, Philosophical Transactions of the Royal Society A, Royal Society, Mechanism of memory effect of paste which dominates desiccation crack patterns, Akio Nakahara; Tomoki Hiraoka; Rokuya Hayashi; Yousuke Matsuo; So Kitsunezaki, Nov. 2018, 377, 20170395-1, 20170395-13, Scientific journal, 10.1098/rsta.2017.0395
- Refereed, JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, SOC CHEMICAL ENG JAPAN, Stress Development Up To Crack Formation in Drying Paste, So Kitsunezaki; Yousuke Matsuo; Akio Nakahara, We investigate the development of stresses in a drying process of paste-like materials theoretically and experimentally. An invasion percolation model on a nonlinear elastic lattice can describe cracking processes resulting from drying contraction as well as dry processes in the bulk of the system and gives a non-dimensional parameter to determine the conditions at which cracking precedes drying. This model also predicts that horizontal tensions increase isotropically with drying. However, paste often exhibits anisotropic crack formation due to plasticity, as is known as the memory effect. We measured stresses in a drying process of calcium carbonate (CaCO3) paste and confirmed that anisotropy in residual stress increases with uniform drying until crack formation when shaking is applied to a paste layer for a short time initially., Oct. 2017, 50, 10, 775, 779, Scientific journal, 10.1252/jcej.16we352
- Refereed, EUROPEAN PHYSICAL JOURNAL E, SPRINGER, Memory effect and anisotropy of particle arrangements in granular paste, So Kitsunezaki; Arina Sasaki; Akihiro Nishimoto; Tsuyoshi Mizuguchi; Yousuke Matsuo; Akio Nakahara, It is known that pastes of fine powder, for example those of clay, retain memory of shaking applied early in a drying process. This memory results in the appearance of anisotropic patterns of desiccation cracks after drying. In this work, we find a similar behavior in pastes consisting of large granular particles, specifically cornstarch and Lycopodium spores. Because of the large particle size, we were able to observe particle arrangements in Lycopodium paste with micro-focus X-ray computerized tomography (mu CT). We prepared pastes consisting of Lycopodium particles and water. Agar was added to the paste in order to allow for solidification during a drying process. In these samples, we found statistical anisotropy induced by shaking applied early in the drying process. This anisotropy possesses a feature that was predicted on the basis of results obtained in previous experimental and theoretical studies., Oct. 2017, 40, 10, 88, Scientific journal, 10.1140/epje/i2017-11578-4
- Refereed, PHYSICAL REVIEW E, AMER PHYSICAL SOC, Effect of disorder on shrinkage-induced fragmentation of a thin brittle layer, Zoltan Halasz; Akio Nakahara; So Kitsunezaki; Ferenc Kun, We investigate the effect of the amount of disorder on the shrinkage-induced cracking of a thin brittle layer attached to a substrate. Based on a discrete element model we study how the dynamics of cracking and the size of fragments evolve when the amount of disorder is varied. In the model a thin layer is discretized on a random lattice of Voronoi polygons attached to a substrate. Two sources of disorder are considered: structural disorder captured by the local variation of the stiffness and strength disorder represented by the random strength of cohesive elements between polygons. Increasing the amount of strength disorder, our calculations reveal a transition from a cellular crack pattern, generated by the sequential branching and merging of cracks, to a disordered ensemble of cracks where the merging of randomly nucleated microcracks dominate. In the limit of low disorder, the statistics of fragment size is described by a log-normal distribution; however, in the limit of high disorder, a power-law distribution is obtained., Sep. 2017, 96, 3, 033006, Scientific journal, 10.1103/PhysRevE.96.033006
- Refereed, EPL, EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY, Shaking-induced stress anisotropy in the memory effect of paste, So Kitsunezaki; Akio Nakahara; Yousuke Matsuo, When paste of fine granular particles and water is shaken in one direction and then left undisturbed, memory of the direction of shaking is retained for a sufficiently long time to result in a directional crack pattern that appears after drying. Although it has been conjectured that anisotropy in residual stresses caused by plastic deformation is responsible for this memory effect, to this time, no evidence of such anisotropy has been found. We experimentally investigated the stress in drying paste by measuring the bending of elastic plates supporting the paste sample and found stress anisotropy developing in paste. Additional bending tests suggested that paste retains plasticity during the drying process and that plastic deformation is not always frozen in place after initial shaking. Copyright (C) EPLA, 2016, Jun. 2016, 114, 6, 64002, Scientific journal, 10.1209/0295-5075/114/64002
- Refereed, Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, Cracking condition of cohesionless porous materials in drying processes, So Kitsunezaki, The invasion of air into porous systems in drying processes is often localized in soft materials, such as colloidal suspensions and granular pastes, and it typically develops in the form of cracks before ordinary drying begins. To investigate such processes, we construct an invasion percolation model on a deformable lattice for cohesionless elastic systems, and with this model we derive the condition under which cracking occurs. A Griffith-like condition characterized by a dimensionless parameter is proposed, and its validity is checked numerically. This condition indicates that the ease with which cracking occurs increases as the particles composing the material become smaller, as the rigidity of the system increases and as the degree of heterogeneity characterizing the drying processes decreases. © 2013 American Physical Society., 17 May 2013, 87, 5, 052805, Scientific journal, 10.1103/PhysRevE.87.052805
- Refereed, ADVANCED POWDER TECHNOLOGY, ELSEVIER SCIENCE BV, Crack growth in drying paste, So Kitsunezaki, The main features of crack patterns in drying paste have been explained by assuming that the paste is an elastic material when cracking occurs. However, recent studies have revealed that the porous and rheological properties of the paste influence the fracture processes. Starting from a spring-network model for a thin layer of paste, the memory effect found by Nakahara and directional crack growth are reviewed. We measured crack speeds in a uniformly dried thin layer of paste and found that crack growth depended significantly on the drying rate. Such dependence suggests that crack growth competes with plastic relaxation in paste. (c) 2011 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved., May 2011, 22, 3, 311, 318, 10.1016/j.apt.2011.03.006
- Refereed, 地質学雑誌, The Geological Society of Japan, Columnar structure and desiccation cracks, 西本明弘; 水口毅; 狐崎創, The formation of three-dimensional prismatic cracks during the drying process of starch-water mixtures is investigated numerically. We assume that the mixture is an elastic porous medium which possesses a stress field and a water content field; the evolution of these fields is represented by, respectively, a spring network and a phenomenological model based on the water potential. As a result of numerical simulations, we reproduce the water content distribution where the drying front propagates from the surface to the interior, and the prismatic structure of cracks grows as the front progresses. The particle-diameter dependence of the columns' scale and the downward coarsening process of the columnar structure are investigated. We find that the non-uniform fracture process is a consequenice of breaking points propagating along the sides of polygonal cross sections. We also examine the effect of the crack networks on the dynamics of the water content field. The contrast between starch columns and geological columnar joints is discussed., 15 Mar. 2011, 117, 3, 183, 191, 10.5575/geosoc.117.183
- Refereed, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, Crack Growth and Plastic Relaxation in a Drying Paste Layer, So Kitsunezaki, Uniform drying causes a quasi-two-dimensional cellular crack pattern in a thin layer of paste. In our previous research, we found that such cracks are created in a capillary state, and that the growth speed is determined by the rate of increase in tension in the layer, rather than by the magnitude of the tension itself. In this paper, we present a theoretical investigation of the effects of increasing negative pore pressure and plastic deformation on crack growth using a modified spring network model. The analytical and numerical results indicate that the stress-rate dependence of crack speed could be caused by the competition between plastic relaxation and crack growth., Dec. 2010, 79, 12, 124802, Scientific journal, 10.1143/JPSJ.79.124802
- Refereed, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, Crack Propagation Speed in the Drying Process of Paste, So Kitsunezaki, We investigated crack propagation in the drying process of a thin layer of calcium carbonate (CaCO3) paste experimentally. Cracks are induced by uniform desiccation from the top surface of it layer at the approximately same water content for various drying conditions. We found that the crack speed is it nonlinear increasing function of the drying rate at the cracking time although the tensile stresses arising in the bulk of paste do not depend practically on the drying rate. The crack speed does not depend significantly on the layer thickness and decreases in the cases in which glycerol is mixed to increase the viscosity of paste. These results suggest that dynamical crack growth occurs with viscoplastic relaxation in the vicinity of crack tips., Jun. 2009, 78, 6, 064801, Scientific journal, 10.1143/JPSJ.78.064801
- Refereed, PHYSICAL REVIEW E, AMER PHYSICAL SOC, Bioconvection and front formation of Paramecium tetraurelia, So Kitsunezaki; Rie Komori; Terue Harumoto, We have investigated the bioconvection of Paramecium tetraurelia in high-density suspensions made by centrifugal concentration. When a suspension is kept at rest in a Hele-Shaw cell, a crowded front of paramecia is formed in the vicinity of the bottom and it propagates gradually toward the water-air interface. Fluid convection occurs under this front, and it is driven persistently by the upward swimming of paramecia. The roll structures of the bioconvection become turbulent with an increase in the depth of the suspension; they also change rapidly as the density of paramecia increases. Our experimental results suggest that lack of oxygen in the suspension causes the active individual motions of paramecia to induce the formation of this front., Oct. 2007, 76, 4, 046301, Scientific journal, 10.1103/PhysRevE.76.046301
- Refereed, PHYSICAL REVIEW E, AMER PHYSICAL SOC, Numerical study of drying process and columnar fracture process in granule-water mixtures, Akihiro Nishimoto; Tsuyoshi Mizuguchi; So Kitsunezaki, The formation of three-dimensional prismatic cracks in the drying process of starch-water mixtures is investigated numerically. We assume that the mixture is an elastic porous medium which possesses a stress field and a water content field. The evolution of both fields is represented by a spring network and a phenomenological model with the water potential, respectively. We find that the water content distribution has a propagating front which is not explained by a simple diffusion process. The prismatic structure of cracks driven by the water content field is observed. The depth dependence and the coarsening process of the columnar structure are also studied. The particle diameter dependence of the scale of the columns and the effect of the crack networks on the dynamics of the water content field are also discussed., Jul. 2007, 76, 1, 016102, Scientific journal, 10.1103/PhysRevE.76.016102
- Refereed, PHYSICA D-NONLINEAR PHENOMENA, ELSEVIER SCIENCE BV, Spatio-temporal patterns of bacteria caused by collective motion, S Kitsunezaki, In incubation experiments on bacterial colonies of Proteus mirabilis, collective motion of bacteria is found to generate macroscopic turbulent patterns on the surface of agar media. We propose a mathematical model to describe the time evolution of the positional and directional distributions of motile bacteria in such systems, and investigate this model both numerically and analytically. It is shown that as the average density of bacteria increases, nonuniform swarming patterns emerge from a uniform stationary state. For a sufficient large density, we find that spiral patterns are caused by interactions between the local bacteria densities and the rotational mode of the collective motion. Unidirectional spiral patterns similar to those observed in experiments appear in the case in which the equilibrium directional distribution is asymmetric. (c) 2006 Elsevier B.V All rights reserved., Apr. 2006, 216, 2, 294, 300, Scientific journal, 10.1016/j.physd.2006.03.001
- Refereed, PHYSICAL REVIEW E, AMER PHYSICAL SOC, Directional crack propagation of granular water systems, T Mizuguchi; A Nishimoto; S Kitsunezaki; Y Yamazaki; Aoki, I, Pattern dynamics of directional crack propagation phenomena observed in drying process of starch-water mixture is investigated. To visualize the three-dimensional structure of the drying-fracture process two kinds of experiments are performed, i.e., resin solidification planing method and real-time measurement of water content distribution with MR instruments. A cross section with polygonal structure is visualized in both experiments. The depth dependency of cell size is measured. The phenomenological model for water transportation is also discussed., May 2005, 71, 5, 056122, Scientific journal, 10.1103/PhysRevE.71.056122
- Refereed, The Japanese Journal of Protozoology, 日本原生動物学会, How Paramecium cells die under a cover glass?, Yoshiomi Takagi; KITSUNEZAKI So; Tae Ohkido; Rie Komori, 2005, 38, 2, 153, 161
- Refereed, GRANULAR MATTER, SPRINGER, Quasi-static deformation of a granular system with a regular arrangement of particles, S Kitsunezaki, In order to study the growth of heterogeneity in granular systems, we investigate the quasi-static deformation of monodisperse particle systems with regular initial arrangements. We construct a linearized model by limiting our consideration to infinitesimal deformations. Assuming Coulomb friction, we introduce new variables to express the slippage distances of particles in contact. The results of our numerical simulations show that heterogeneities appear through a fingering-like instability and develop into several microscopic shear zones. The equations in our model can be reduced to simpler equations in the limit of small tangential interactions using a perturbative analysis. In the long wavelength limit, the equations are analogous to models of Laplacian growth, such as the fuse problem. We investigate the instability of critical stress states and the competitive growth of microscopic shear zones., Dec. 2004, 6, 4, 221, 228, Scientific journal, 10.1007/s10035-004-0182-x
- Refereed, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, Dynamic scaling of the growing rough surfaces, N Kobayashi; O Moriyama; S Kitsunezaki; Y Yamazaki; M Matsushita, We have numerically investigated the self-affinity of the bacterial colony model. In order to examine the growth exponent beta, we find a new approach to the dynamic scaling hypothesis for the growing rough surface. We have first investigated the self-affinity of the well-known Eden model to check the validity of the new approach. The obtained results of the exponents alpha congruent to 0.50 and beta congruent to 0.33 coincide with the wellknown values of the exponents of the Eden model. We have then applied it successfully to growing interfaces produced by the bacterial colony model. We have found that the self-affinity of the bacterial colony model is characterized as alpha congruent to 0.80 and beta congruent to 0.65., Aug. 2004, 73, 8, 2112, 2116, Scientific journal, 10.1143/JPSJ.73.2112
- Refereed, Granular Matter, The Creation Process of Faults in Quasi-static Deformation, S. Kitsunezaki; A. Kurumatani, We investigated quasi-static deformation processes of granular systems both by experiments and numerical calculations. We simulated the deformation of a regular arrangement of particles using the discrete elements method and found that the initial deformation of the granular system causes the formation of microscopic shear zones through a fingering-like instability of the stress field. These microscopic shear zones propagate as their localized strain increases in magnitude and then evolves into macroscopic faults. The picture of a fingering-like instability is consistent with our experimental results concerning the creation sequence and spacing of faults appearing in a granular system contained in a V-shaped container., Feb. 2004, 5, 4, 185, 192, Scientific journal, 10.1007/s10035-003-0150-x
- Refereed, GRANULAR MATTER, SPRINGER-VERLAG, The creation process of faults in quasi-static deformation, S Kitsunezaki; A Kurumatani, We investigated quasi-static deformation processes of granular systems both by experiments and numerical calculations. We simulated the deformation of a regular arrangement of particles using the discrete elements method and found that the initial deformation of the granular system causes the formation of microscopic shear zones through a fingering-like instability of the stress field. These microscopic shear zones propagate as their localized strain increases in magnitude and then evolves into macroscopic faults. The picture of a fingering-like instability is consistent with our experimental results concerning the creation sequence and spacing of faults appearing in a granular system contained in a V-shaped container., Feb. 2004, 5, 4, 185, 192, Scientific journal, 10.1007/s10035-003-0150-x
- Refereed, PHYSICAL REVIEW E, AMERICAN PHYSICAL SOC, Fracture patterns induced by desiccation in a thin layer, S Kitsunezaki, We study a theoretical model of mud cracks, that is, the fracture patterns resulting from the contraction with drying in a thin layer of a mixture of granules and water. In this model, we consider the slip on the bottom of this layer and the relaxation of the elastic field that represents deformation of the layer. Analysis of the one-dimensional model gives results for the crack size that are consistent with experiments. We propose an analytical method of estimation for the growth velocity of a simple straight crack to explain the very slow propagation observed in actual experiments. Numerical simulations reveal the dependence of qualitative nature of the formation of crack patterns on material properties. [S1063-651X(99)05412-4]., Dec. 1999, 60, 6, 6449, 6464, Scientific journal, 10.1103/PhysRevE.60.6449
- Refereed, JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, PHYSICAL SOC JAPAN, Interface dynamics for bacterial colony formation, S Kitsunezaki, We propose a differential-equation model with a nonlinear diffusion term for explaining pattern formation of bacterial colonies, and carry out its numerical simulations. Our model is reduced to an interface dynamics by means of a systematic perturbation method. This is similar to a model system for viscous fingering except that the field around an interface obeys a diffusion equation and that surface tension does not work on the interface. How the difference in morphology results depending on the condition is explained qualitatively., May 1997, 66, 5, 1544, 1550, Scientific journal, 10.1143/JPSJ.66.1544
- Refereed, PHYSICA D, ELSEVIER SCIENCE BV, Modeling for fingering patterns with an assembly of splitting elements, S Kitsunezaki, For the purpose of understanding fingering patterns, we propose a simple model system composed of splitting elements where we regard a tip of each finger as a basic dynamical unit. Numerical simulations of the model reproduce turbulent states, fractal- and tree-like structures and spatio-temporal intermittency which are all quite similar in behavior to real systems., Apr. 1997, 102, 3-4, 262, 274, Scientific journal, 10.1016/S0167-2789(96)00196-0
- Refereed, Physical Review E, American Physical Society (APS), X-ray computerized tomography observation of Lycopodium paste incorporating memory of shaking, So Kitsunezaki; Akihiro Nishimoto; Tsuyoshi Mizuguchi; Yousuke Matsuo; Akio Nakahara, 21 Apr. 2022, 105, 4, 044902, Scientific journal, 10.1103/PhysRevE.105.044902
- Refereed, Soft Matter, Royal Society of Chemistry ({RSC}), Evolution of anisotropic crack patterns in shrinking material layers, Roland Szatmári; Zoltán Halász; Akio Nakahara; So Kitsunezaki; Ferenc Kun, Sep. 2021, 17, 10005, 10015, Scientific journal, 10.1039/d1sm01193f
- Refereed, Scientific Reports, Springer Science and Business Media LLC, Scale-free bursting activity in shrinkage induced cracking, Roland Szatmári; Akio Nakahara; So Kitsunezaki; Ferenc Kun, Abstract Based on computer simulations of a realistic discrete element model we demonstrate that shrinkage induced cracking of thin layers of heterogeneous materials, generating spectacular crack patterns, proceeds in bursts. These crackling pulses are characterized by scale free distributions of size and duration, however, with non-universal exponents depending on the system size and shrinking rate. On the contrary, local avalanches composed of micro-cracking events with temporal and spatial correlation are found to obey a universal power law statistics. Most notably, we demonstrate that the observed non-universality of the integrated signal is the consequence of the temporal superposition of the underlying local avalanches, which pop up in an uncorrelated way in homogeneous systems. Our results provide an explanation of recent acoustic emission measurements on drying induced shrinkage cracking and may have relevance for the acoustic monitoring of the electro-mechanical degradation of battery electrodes., 26 Mar. 2024, 14, 1, Scientific journal, 10.1038/s41598-024-57368-5
- Wiley-{VCH} Verlag {GmbH} {\&} Co. {KGaA}, Desiccation Cracks and their Patterns, Lucas Goehring; Akio Nakahara; Tapati Dutta; So Kitsunezaki; Sujata Tarafdar, 11 May 2015, 10.1002/9783527671922
MISC
- Not Refereed, EPJ Web Conf.(Powders and Grains 2017 – 8th International Conference on Micromechanics on Granular Media), Erasure of memory in paste by irradiation of ultrasonic waves, A. Nakahara; R. Yoneyama; M. Ito; Y. Matsuo; S. Kitsunezaki, 2017, 140, 12007
- Not Refereed, 表面, ペーストの乾燥破壊とレオロジー, 狐崎 創, 2011, 48, 11, 343, 354
- Refereed, Butsuri, The Physical Society of Japan (JPS), Starch Columnar Joints, NISHIMOTO Akihiro; MIZUGUCHI Tsuyoshi; KITSUNEZAKI So, Cracks formed in drying granule water mixtures, e.g., soils, are ubiquitous phenomena, but details remain still unclear. Recently, the crack patterns formed in drying starch water mixtures have attracted considerable attention for their likeness to columnar joints. Intriguing columnar joints has fascinated many people for centuries and are studied mainly by field works in geology. By studying detail nature of drying cracks and comparing them with columnar joints, progress in understanding both phenomena is expected., 2009, 64, 10, 758, 762
- Refereed, 粉体工学会誌, ペーストの乾燥による亀裂成長とパターン形成, 狐崎 創, 2009, 46, 9, 664, 670
- Not Refereed, 九州大学応用力学研究所研究集会報告集, 乾燥破壊での亀裂の伝播, 狐崎 創, 2008, 19ME-S3
- Refereed, PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, PROGRESS THEORETICAL PHYSICS PUBLICATION OFFICE, Spatio-temporal patterns in colonies of rod-shaped bacteria, S Kitsunezaki, In incubation experiments of bacterial colonies of Proteus Mirabilis, macroscopic spatiotemporal patterns, such as turbulent and unidirectional spiral patterns, appear in colonies. Considering only kinetic propeties of rod-shaped bacteria, we propose a phenomenological model for the directional and positional distributions. As the average density increases, homogeneous states bifurcate sub-critically into nonuniform states exhibiting localized collective motion, and spiral patterns appear for sufficiently large density. These patterns result from interactions between the local bacteria densities and the order parameter representing collective motion. Our model can be described by reduced equations using a perturbative method for large density. The unidirectionality of sprial rotation is also discussed., 2006, 161, 161, 224, 227, 10.1143/PTPS.161.224
- Not Refereed, RIMS Kokyuroku, Kyoto University, Dynamic Scaling of the Growing Rough Surfaces (Mathematical Aspects of Pattern Formation in Complex Fluids), Kobayashi Naoki; Saito Kazuaki; Tatsuya Ozawa; Moriyama Osamu; Kitsunezaki So; Yamazaki Yoshihiro; Matsushita Mitsugu, 2005, 1413, 211, 219
- Not Refereed, 物性研究, 粗い界面成長に対するダイナミックスケーリング, 小林奈央樹; 小澤達哉; 齋藤和亮; 森山修; 狐崎創; 山崎義弘; 松下貢, 2004, 83, 373, 374
- Not Refereed, ``Slow Dynamics in Complex Systems'', edited by M.Tokuyama, American Institute of Physics, Initial Deformation Process in Granular Matter, KITSUNEZAKI So, 2004, 154, 5
- Not Refereed, POWDERS AND GRAINS 2001, A A BALKEMA PUBLISHERS, Directional crack propagation in drying process of wet granules, T Mizuguchi; A Nishimoto; S Kitsunezaki; Y Yamazaki; Aoki, I, Pattern formation phenomena of crack observed in drying process of wet granular materials are investigated. With some combination of granular material and liquid, nonuniform shrinkage induced by drying process causes crack formation of bulk sample in several ways. Especially, directional crack propagation and columnar structure formation are observed in the experiments. Measurement of water content distribution during drying process shows an existence of front at which crack tips locate., 2001, 55, 58
- Not Refereed, POWDERS AND GRAINS 2001, A A BALKEMA PUBLISHERS, Stripe patterns induced by slow deformation of a container, S Kitsunezaki; A Kurumatani, We report experimental results for a system in which stripe patterns appear on the surface of granular matter. These stripes are induced by the slow deformation of the container. We find that as the average size of granular particles becomes larger, stripes become less pronounced, while the spacing between them remains roughly constant. We find that beneath these stripes, faults appear which are aligned parallel to one another., 2001, 309, 312
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 9aAY-9 Detection of stress anisotropy induced by the memory effect, Kitsunezaki So; Nakahara Akio; Matsuo Yousuke, 22 Aug. 2014, 69, 2, 160, 160
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 30aPS-67 Memory of Vibration in Starch Paste, Sasaki Arina; Nakahara Akio; Matsuo Yousuke; Kitsunezaki So, 05 Mar. 2014, 69, 1, 374, 374
- J. Soc. Power Technol. Jpn, Crack growth and pattern formation induced by desiccation in paste, KITSUNEZAKI S., 2009, 49, 664, 670
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 30aPS-80 Development of a growing elastic string, Ishikawa Eri; Kitsunezaki So, 03 Mar. 2009, 64, 1, 339, 339
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 21aEC-11 Cross Section Patterns of Fracture in Drying Paste, Aoki Michiko; Kitsunezaki So, 01 Mar. 2010, 65, 1, 380, 380
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 28aTF-7 Drying process of paste with elastic deformation, Itoh Hanako; Kitsunezaki So, 03 Mar. 2011, 66, 1, 347, 347
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), Pattern formation of granules induced by quasistatic deformation of a container, Kurumatani Akemi; Kitsunezaki So, 10 Mar. 2000, 55, 1, 235, 235
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 2-dimensional crack pattern formation induced by desiccation process, KITSUNEZAKI So, 05 Sep. 1998, 53, 2, 792, 792
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), Pattern Formation of Crack Induced by Dessication Process II, NISHIMOTO A.; KITSUNESAKI S.; YAMASAKI Y.; MIZUGUCHI T., 05 Sep. 1998, 53, 2, 760, 760
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 27aWD-5 Dynamic scaling of the growing rough surfaces, Kobayashi Naoki; Moriyama Osamu; Kitsunezaki So; Yamazaki Yoshihiro; Matsushita Mitsugu, 03 Mar. 2004, 59, 1, 262, 262
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 5p-YD-13 Pattern Formation of Crack Induced by Dessication Process, Nishimoto A.; Kitsunezaki S.; Yamazaki Y.; Mizuguchi T., 16 Sep. 1997, 52, 2, 731, 731
- Abstracts of the meeting of the Physical Society of Japan. Annual meeting, The Physical Society of Japan (JPS), 28a-C-5 Pattern Formation of Bacterial Colonies, Kitsunezaki So, 16 Mar. 1994, 49, 3, 495, 495
- Abstracts of the meeting of the Physical Society of Japan. Sectional meeting, The Physical Society of Japan (JPS), 1D fingering model, Kitsunezaki So, 12 Sep. 1995, 1995, 3, 580, 580
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 24pJF-11 Measurement of strain and stress in memory effect of paste, Nakahara A.; Kitsunezaki S.; Matsuo Y.; Nakayama H.; Ooshida T.; Otsuki M.; Goto S.; Matsumoto T., 24 Aug. 2011, 66, 2, 351, 351
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 24pJF-10 Role of particle interaction in retention of memories in paste, Nakahara A.; Matsuo Y.; Nakayama H.; Ooshida T.; Otsuki M.; Kitsunezaki S., 24 Aug. 2011, 66, 2, 351, 351
- Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), Modelling and Numerical Analysis of the Pattern Formation of Bacterial Colonies, Kobayashi Naoki; Sato Takuya; Kitsunezaki So; Yamazaki Yoshihiro; Matsushita Mitsugu, 15 Aug. 2003, 58, 2, 210, 210
- Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 19pBS-9 X-ray CT observation of particle arrangements of paste exhibiting the memory effect in drying fracture, Kitsunezaki S.; Nishimoto A.; Matsuo Y.; Nakahara A.; Mizuguchi T., 2016, 71, 2838, 2838, 10.11316/jpsgaiyo.71.1.0_2838
- Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 17aCR-8 Non-destructive structural analysis of memory effect of magnetic paste, Uchida K.; Nakahara A.; Matsuo Y.; Izui H.; Kitsunezaki S.; Kun Ferenc, 2015, 70, 2624, 2624, 10.11316/jpsgaiyo.70.2.0_2624
- Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 21pAK-7 Detection of stress anisotropy induced by the memory effect (II), Kitsunezaki So; Nakahara Akio; Matsuo Yousuke, 2015, 70, 2903, 2903, 10.11316/jpsgaiyo.70.1.0_2903
Books etc
- Desiccation Cracks and their Patterns: Formation and Modelling in Science and Nature, Wiley, 2015, Not Refereed, 9783527412136
Presentations
- S. Kitsunezaki; A.Sasaki; A.Nishimoto; Y.Matsuo; A. Nakahara; T.Mizuguchi, UK-JSPS joint research seminar(Nottingham Trent Univ., UK), Anisotropy of Particle Arrangements in Granular Paste with Memory of Shaking, 31 Aug. 2018
- 日本物理学会, 流体の侵入でできる固化界面の運動について, 2018
- HAS-JSPS Fukui workshop, Dynamics of a solidification interface made by fluid invasion, 2018
- ジャムドマターの非ガウスゆらぎとレオロジー, Anisotropy of Particle Arrangements in Granular Paste with Memory of Shaking, 2017
- Nara Workshop on Nonlinear Dynamics under HAS-JSPS Joint Research Project, Development of stress anisotropy in the memory effect of paste, 2016
- 日本物理学会, 乾燥破壊の記憶効果を示すペーストのX線CTによる粒子配列の観察, 2016
- 7th Hungary-Japan Bilateral Workshop on Statistical Physics of Breakdown Phenomena, X-ray CT observation of the particle arrangement in paste exhibiting the memory effect of shaking, 2016
- 31st IUGG Conference on Mathematical Geophysics(CMG2016), Stress Anisotropy Induced by the Memory Effect of Drying Paste, 2016
- 20th International Drying Symposium(IDS2016), Stress Development up to Crack Formation in Drying Paste, 2016
- 第3回同志社大学生命物理科学研究室 夏季研究会, ペーストの破壊と亀裂のパターン, 2016
- 鳥取非線形研究会2016, Granular paste の記憶効果と粒子配置の異方性, 2016
- Nara Workshop on Nonlinear Dynamics 2016 Dec. under HAS-JSPS Joint Research Project, The memory effect and the particle arrangement in granular paste, 2016
- Nara Workshop on Nonlinear Dynamics under HAS-JSPS Joint Research Project, Development of stress anisotropy in the memory effect of paste, 2016
- 7th Hungary-Japan Bilateral Workshop on Statistical Physics of Breakdown Phenomena, X-ray CT observation of the particle arrangement in paste exhibiting the memory effect of shaking, 2016
- 31st IUGG Conference on Mathematical Geophysics(CMG2016), Stress Anisotropy Induced by the Memory Effect of Drying Paste, 2016
- 20th International Drying Symposium(IDS2016), Stress Development up to Crack Formation in Drying Paste, 2016
- Nara Workshop on Nonlinear Dynamics 2016 Dec. under HAS-JSPS Joint Research Project, The memory effect and the particle arrangement in granular paste, 2016
- 日本物理学会, 記憶効果による応力異方性の検出(II), 2015
- 早稲田大学山崎研究室セミナー, ペーストの乾燥破壊 --特に揺れの記憶での応力異方性について--, 2015
- 科研費プロジェクト「"ラグランジュ描像でのテンソル的統計量を軸とする塑性流動と乱流の理論の共同展開" 」主催セミナー, ペーストの乾燥破壊・揺れの記憶での応力異方性について, 2015
- 第5回ソフトマター研究会, 乾燥前の揺れによって生じるペーストの乾燥中の応力異方性の発達, 2015
- Spatiotemporal Pattern Formation in Biological and Active Matters, Dynamics of a growing elastic string, 2014
- 日本物理学会, 澱粉ペーストの乾燥破壊における亀裂成長, 2014
- 日本物理学会, 澱粉ペーストの揺れの記憶, 2014
- 日本物理学会, 記憶効果による応力異方性の検出, 2014
- Spatiotemporal Pattern Formation in Biological and Active Matters, Dynamics of a growing elastic string, 2014
- Mini-workshop at Shantiniketan, Cracking condition of paste-like materials in drying processes, 2013
- The international symposium "Self-organization and emergent dynamics in active soft matter", Drying crack in cohesionless porous materials, 2013
- 日本物理学会, ペーストの乾燥過程での破壊条件, 2013
- Max Planck Institute for Dynamics and Self-Organization,Seminar dynamics of complex fluids, Drying and cracking of paste-like materials, 2013
- Droplet 2013, 1st Int. Workshop on Wetting and evaporation: droplets of pure and complex fluids, Fracture condition of drying paste, 2013
- 5th Hungary Japan Bilateral Workshop, Drying and fracture of cohesionless porous systems, 2013
- 日本物理学会, 澱粉ペーストの Type I 亀裂, 2013
- 鳥取非線形研究会2013, 澱粉ペーストの揺れの記憶, 2013
- 鳥取非線形研究会2013, 乾燥破壊における澱粉ペーストの亀裂速度, 2013
- Mini-workshop at Shantiniketan, Cracking condition of paste-like materials in drying processes, 2013
- The international symposium "Self-organization and emergent dynamics in active soft matter", Drying crack in cohesionless porous materials, 2013
- Max Planck Institute for Dynamics and Self-Organization,Seminar dynamics of complex fluids, Drying and cracking of paste-like materials, 2013
- Droplet 2013, 1st Int. Workshop on Wetting and evaporation: droplets of pure and complex fluids, Fracture condition of drying paste, 2013
- 5th Hungary Japan Bilateral Workshop, Drying and fracture of cohesionless porous systems, 2013
- 塗布・乾燥セミナー, ペーストの乾燥による亀裂形成のメカニズム, 2012
- Nonlinearity workshop in Tottori 2012, Crack condition in a drying process, 2012
- 数学・物理学・情報科学の研究交流シンポジウム, 成長するひもの形の時間発展, 2012
- Nonlinearity workshop in Tottori 2012, Crack condition in a drying process, 2012
- 日大塑性研究会, ペーストの亀裂速度実験・続報, 2011
- 狐崎創; 西本明弘; 中原明生; 松尾洋介; 水口毅, 日本物理学会第76年次大会, 揺れの記憶を持つ石松子ペーストのμX-CT観察(II) ～異方的構造の解析～, 14 Mar. 2021
- 狐崎創, Nonliner Science Seminar, 東大非線形物理学研究室, 成長する紐や膜の形〜縮約が役立ちそうな２題〜, 23 Sep. 2020
- 狐崎創; 西本明弘; 河原敏男; 中原明生; 松尾洋介; 水口毅, 日本物理学会第75年次大会, 揺れの記憶を持つ石松子ペーストのμX-CT観察, 16 Mar. 2020
- So Kitsunezaki; Rena Ojiri, Fracture and Geomorphology: Osaka workshop for nonequilibrium physics(Osaka Univ.), Response of a plasmodium of true slime mold to centrifugal force, 18 Sep. 2019
- 狐崎創; 尾尻礼菜, 日本数理生物学会大会2019(東京工業大学大岡山キャンパス), 真性粘菌変形体の遠心力に対する応答について, 16 Sep. 2019
- So Kitsunezaki; Chika Yamanaka, Research Seminar: Royal Society/JSPS collaboration project, (Nottingham Trent Univ., UK), Dynamics of a solidification front made by invasion of fluid with a different temperature, 30 Aug. 2019
- 狐崎創; 尾尻礼菜, 第15回京都算楽会（奈良女子大学、C141), 真性粘菌変形体の遠心力に対する応答について, 11 May 2019
- 狐崎創, 九州大学 本庄・坂口研セミナー, ペーストの乾燥破壊, 21 Nov. 2018
- So Kitsunezaki, The 9th International Conference on Multiscale Materials Modeling(Osaka International Convention Center,Osaka), Dynamics of a solidification front made by invasion of fluid with a different temperature, 31 Oct. 2018
- 狐崎創, 日本物理学会第78回年次大会, パラフィン液滴の冷水への衝突での固化膜形成と破壊, Oral presentation, 17 Sep. 2023
- So Kitsunezaki; Rina Nakashioya, Statphys28, Morphology of solid films formed by collision of a paraffin droplet with water, Poster presentation, 07 Aug. 2023
- 青柳紗月; 狐崎創, 日本物理学会2024年春季大会, 真正粘菌変形体の外力に対する応答II, Oral presentation, 21 Mar. 2024
- 原明穂; 狐崎創, 日本物理学会2024年春季大会, 水面に浮かんだ粒子の凝集過程のシミュレーションⅡ, Oral presentation, 19 Mar. 2024
- 佐久間絢子; 狐崎創, 日本物理学会2024年春季大会, パラフィンワックスの冷却によって生じる亀裂の研究II, Oral presentation, 18 Mar. 2024
- 青柳紗月; 狐崎創, 日本物理学会第78回年次大会, 真正粘菌変形体の外力に対する応答, Oral presentation, 18 Sep. 2023
- 佐久間絢子; 狐崎創, 日本物理学会第78回年次大会, パラフィンワックスの冷却によって生じる亀裂の研究, Oral presentation, 17 Sep. 2023
- 原明穂; 狐崎創, 日本物理学会第78回年次大会, 水面に浮かぶ粒子の凝集過程とパターン形成のシミュレーション, Oral presentation, 17 Sep. 2023
- 小田桐和奏; 松尾洋介; 中原明生; 狐崎創, 日本物理学会第78回年次大会, 粉体の接触角がペーストのメモリー効果に及ぼす影響, Oral presentation, 17 Sep. 2023
- 山田光希; 波多野恭弘; 狐崎創, 日本物理学会第78回年次大会, 多層stick-slipモデルにおけるすべりの挙動, Oral presentation, 17 Sep. 2023
- 原明穂; 狐崎創, 日本物理学会2023年春季大会, 水面に浮かぶ粒子の凝集過程のシミュレーション, Oral presentation, 22 Mar. 2023
- 中塩屋璃奈; 狐崎創, 日本物理学会2023年春季大会, 高温のパラフィン液滴と水面との衝突における固化膜形成のダイナミクスⅡ, Oral presentation, 22 Mar. 2023
- 田口真実; 狐崎創, 日本物理学会2023年春季大会, 気体の圧力による亀裂形成のフェーズフィールドモデル, Oral presentation, 22 Mar. 2023
- 中塩屋璃奈; 狐崎創, 日本物理学会2022年秋季大会, 高温のパラフィン液滴と水面との衝突における固化膜形成のダイナミクス, Oral presentation, 13 Sep. 2022
- 青柳紗月; 狐崎創, 2022年度日本数理生物学会年会, 外力に勾配のある環境下での真正粘菌変形体の応答, Oral presentation, 07 Sep. 2022
Research Projects
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2020, 31 Mar. 2024, 20K03886, Variety of the memory retention ability in the memory effect of paste, 中原 明生; 狐崎 創, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nihon University, 4290000, 3300000, 990000, 粉と水を混ぜた高濃度コロイドサスペンション（ペースト）は己の動きを記憶し、その記憶に従って乾燥させた時に割れやすい方向が決まる。揺れを記憶した場合は揺れに垂直に割れやすくなり、流れを記憶した場合は流れに平行に割れやすくなり、磁場を記憶した場合は磁場に平行に割れやすくなる。 令和２年度までの研究でペーストを流す流路にスリットがある場合はスリットの前後で亀裂パターンの転移が起こることを報告したが、令和３年度の研究により、条件によってはその転移にヒステリシスが観測されるものがあることが分かった。具体的には、スリット通過前は流れに平行に割れやすく、スリット通過後はどこまで流れても流れに垂直に割れやすいままで、スリットを通過したという過去のヒステリシスが強く残ることが分かった。一方、揺れを記憶する状態のペーストを注ぎ込んでゆっくりとスリットを通過させると、スリット通過前は移動方向に垂直に割れやすく、スリット通過後は移動方向に平行に割れやすくなること、さらにスリット通過後にある距離移動すると再び移動方向に垂直に割れやすくなることが分かった。この結果は、揺れの記憶と流れの記憶は元々割れやすい方向が９０度異なるが、スリットを通過することで割れやすい方向がお互いに入れ替わること、さらに、流れの記憶でできる構造は揺れの記憶よりもはるかにヒステリシスが強いことを示している。今後はミクロな構造解析を行い、揺れと流れの記憶の構造の違いと転移現象のメカニズムを解明していく。 ハンガリーの破壊理論の研究者との共同研究においては、揺れを記憶し異方的な亀裂パターンを生じるペーストの乾燥破壊のシミュレーションを行なったところ、乾燥破壊の初期段階では揺れに垂直に亀裂が走り、中期段階では初期亀裂と垂直な方向に亀裂が走り、後期段階では亀裂がネットワークを構成して亀裂パターンが形成されるなど実験結果の再現にも成功した。, kaken;rm:published_papers
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2018, 31 Mar. 2022, 18K03560, Fracture of paste: microstructures governing memory and roles of plastic deformation, Kitsunezaki So, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 4420000, 3400000, 1020000, Paste-like mixtures of granular material and liquid exhibit the distinctive property of memorizing external perturbation and then forming anisotropic crack patterns. In this research we investigated samples of paste with such memory of shaking or a magnetic field, that were prepared in systematically chosen conditions, and obtained their 3D images by using micro-focus X-ray computerized tomography at the large synchrotron radiation facility Spring-8. Image analysis indicated that the direction of external perturbation is retained as the arrangement or directions of particles, in particular, density fluctuation forming the structure of interstices affects the direction of crack growth. We also reproduced anisotripic arrangements of neighboring particles numerically and revealed the relation between anistropic fracture properties and crack patterns., kaken;rm:published_papers
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2016, 31 Mar. 2019, 16K05485, Control of crack formation and material property by using nonlinear response of memory in paste under external perturbations, NAKAHARA Akio, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nihon University, 4810000, 3700000, 1110000, Due to its plasticity, a densely packed colloidal suspension, called a paste, remembers the direction of its vibration, shear and magnetic field, and these memories control preferential directions for cracks to propagate. To reveal the mechanism of this memory effect of paste, systematic experiments to imprint and rewrite memories in paste and numerical simulations based on theoretical models are performed. It is shown that a memory of vibration is kept as a residual tension along the vibration inside plastic media and a memory of shear is maintained as an elongated clusters of colloidal particles along shear direction. As for a memory of magnetic field, X-ray CT scan reveals that magnetic colloidal particles rotate and move to make chains toward the direction of magnetic field. These structures called memories in paste control the crack formation. By irradiating ultrasonic waves to paste, we find that memories in paste are erased and the breaking strength of the material increases., url;kaken
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2015, 31 Mar. 2018, 15K05213, Joint development of theories of plastic flows and turbulence pivoted on tensorial statistical quantities in Lagrangian description, OOSHIDA Takeshi; KITSUNEZAKI So, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Tottori University, 3250000, 2500000, 750000, As a basic study on mechanism of solidification and fluidization of non-crystalline materials, commonly encountered as foods and cosmetics, a theoretical investigation was performed on collective motions of particles in colloidal systems (typically consisting of numerous small particles dispersed in water). Application of methods borrowed from theories of fluid turbulence to colloidal systems has allowed construction of a theoretical framework for considering the directionality of motion of the particles, without causing inconsistency in regard to the relation between the endogenous and exogenous motions. As a result, a vortical motion of colloidal particles was successfully reproduced by the theory., url;kaken
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2014, 31 Mar. 2017, 26400395, Research on Internal Structures Responsible for the Fracture Properties of Wet Granular Materials, Kitsunezaki So; MIZUGUCHI Tsuyoshi; OTSUKI Michio; NISHIMOTO Akihiro, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 4810000, 3700000, 1110000, When paste-like mixtures of fine solid particles and liquid are shaken horizontally and left undisturbed, lines of desiccation cracks perpendicular to the direction appear after drying. We investigated wet granular materials (pastes) with such memory of shaking. We developed the method of stress measurements by using plate springs and found that stress anisotropy increases as drying proceeds in calcium carbonate pastes. We next confirmed that two types of pastes of large granules, starch and Lycopodium powder, exhibit the memory effect of shaking, and found statistical anisotropies in the microscopic arrangements of Lycopodium particles by using micro focus X-ray CT, which are consistent with macroscopic anisotropy in stresses. These are the first results which indicate the existence of anisotropic structures before the formation of desiccation cracks and important information to clarify the memory effect., url;kaken
- Grant-in-Aid for Scientific Research (C), 01 Apr. 2012, 31 Mar. 2015, 24540404, Collaboration of statistical mechanics and fluid mechanics for development of new theories of plastic flows and turbulence, OOSHIDA Takeshi; NAKAHARA Akio; GOTO Susumu; MATSUMOTO Takeshi; OTSUKI Michio; KITSUNEZAKI So, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Tottori University, 5070000, 3900000, 1170000, In order to lay a future foundation for a microscopic theory of plastic flows, an idea of importing the Lagrangian correlation, also known as the label variable method, into the statistical theory of dense colloidal liquids from the theory of fluid turbulence was tested and developed. The usefulness of this idea was demonstrated by analytical calculation of four-point space-time correlations in single-file diffusion in one-dimensional colloidal systems; besides, the label variable method is shown to be extensible to the two-dimensional cases., url;kaken
- Grant-in-Aid for Scientific Research (B), 01 Apr. 2010, 31 Mar. 2015, 22340112, Control of crack formation using rheology of plastic fluid, NAKAHARA Akio; KITSUNEZAKI So; OTSUKI Michio; OOSHIDA Takeshi; MATSUO Yousuke; NAKAYAMA Hiroshi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Nihon University, 20020000, 15400000, 4620000, Densely packed colloidal suspension, called paste, remembers the direction of mechanical motion, such as vibration and flow, and, if the paste is dried, its memory is visualized as the direction of crack propagation. In this project, we tried to reveal the mechanism of memory effect of paste and applied the memory effect to control crack formation. We found that the attractive force between particles is necessary for the memory of flow. Magnetic paste remembers the direction of the magnetic field and the desiccation cracks run along the magnetic field. By applying a vertical vibration to the paste, we came to control the position of crack formation by localizing the area of horizontal vibration. Finally, we succeeded in erasing the memory of external field in paste by applying ultrasonic waves to the paste. As the paste becomes more homogeneous, irradiation of ultrasonic waves to a paste increases the breaking strength of the paste., url;kaken
- Grant-in-Aid for Scientific Research (C), 2011, 2013, 23540452, Interaction of paste and fracture, KITSUNEZAKI So; NAKAHARA Akio; OOSHIDA Takeshi; OTSUKI Michio; MIZUGUCHI Tsuyoshi, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Nara Women's University, 5590000, 4300000, 1290000, Drying changes slurries of fine solid particles and liquid to plastic fluids with appearance of finite yield stresses and generally creates cracks in the vicinity of the plastic limit. The purpose of this research is to clarify the effect of plasticity to crack growth, the anisotropy of material properties induced by the memory effect, and the fracture condition of drying paste. A mathematical model based on invasion percolation on a nonlinear elastic lattice was proposed to understand drying and cracking in a unified manner and the fracture condition was given theoretically. We carried out compression tests in experiments and found the memory effect for starch paste, which is one of typical shear thickening fluids. We also confirmed the dependency of crack speed on the layer thickness for starch paste, which was qualitatively different from that for calcium carbonate paste., url;kaken
- Grant-in-Aid for Young Scientists (B), 2007, 2010, 19740240, Granular rheology in slow deformation processes, KITSUNEZKI So, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B), Nara Women's University, 3760000, 3100000, 660000, Experiments on drying fracture in granular paste revealed that crack growth is dynamic fracture with dying rate dependence. Theoretical analysis indicated that competition between crack growth and plastic relaxation can cause such dependence. The studies on columnar joints of starch paste and an invasion percolation model with fracture processes were also reported., url;url;kaken
- 若手研究(B), 2002, 2004, 14740234, 粉体変形過程の力学, 狐崎 創, 日本学術振興会, 科学研究費助成事業 若手研究(B), 奈良女子大学, 3100000, 3100000, 粉体の準静的な変形過程で生じる断層と破壊の力学を非線形動力学の視点から研究した。 昨年度までに乾燥粉体での変形実験、数値計算、微小変形過程での理論解析を行い、断層の初期成長過程で誘電破壊と類似の競合現象が現れること示したが、今年度はその研究を進めると共にこれまでの成果を発表した。論文は研究発表欄にまとめた通りであるが、この他に、国際会議STATPHYS22及びそのサテライトミーティングに参加し研究発表を行った。 これに加えて、本年度は粉体間に水分が介在することで凝集力が働く場合の破壊現象について実験及び理論的な研究を2つ行った。第1は、大阪府大の水口氏らとともに以前から共同で行っている三次元的な乾燥破壊で現れる柱状節理構造に関する研究である。実験結果を中心に論文が出版される予定であるが、この現象は亀裂自身が水分を蒸発させて収縮をコントロールしながら成長するself-driven crackである可能性が高い。数理モデルを作るために粉体内の水分の時間発展方程式と、亀裂の進展条件を議論し、理論的考察を行った。第2は、準二次元的な乾燥破壊での亀裂の進展速度の実験的研究である。粉体の乾燥破壊では、通常の固体ではあり得ないような非常に遅い速度の亀裂成長が観察されており、粉体に特有な強いエネルギー散逸が亀裂の進展速度にどう反映するかは興味深い課題である。まだ予備的な研究であるが、温度湿度をモニターしながらの速度測定を学生と共に行い、亀裂速度の厚さ依存性などについて精度は不十分ながらも新しい結果を得た。これに関しては、条件の制御が難しいため交付期間終了後も引き続き研究を継続し、より本格的な実験に発展させる予定である。, kaken