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Shinsuke Takagi - One of the best experts on this subject based on the ideXlab platform.
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photochemical properties of mono tri and penta cationic antimony v metalloporphyrin derivatives on a Clay Layer surface
Journal of Physical Chemistry A, 2013Co-Authors: Takamasa Tsukamoto, Tetsuya Shimada, Shinsuke TakagiAbstract:Three types of mono-, tri-, and penta-cationic antimony(V) porphyrin derivatives (SbVPors) were synthesized, and their photochemical properties on the anionic Clay were systematically investigated. SbVPor derivatives are dihydroxo(5,10,15,20-tetraphenylporphyrinato)antimony(V) chloride ([SbV(TPP)(OH)2]+Cl–), dihydroxo[5,10-diphenyl-15,20-di(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) trichloride ([SbV(DMPyP)(OH)2]3+3Cl–), and dihydroxo[5,10,15,20-tetrakis(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) pentachloride ([SbV(TMPyP)(OH)2]5+5Cl–). The photochemical behaviors of three cationic SbVPors with and without Clay were examined in aqueous solution. For all SbVPor, aggregation behaviors were not observed in the Clay complexes even at high density adsorption conditions. The transition probabilities and fluorescence quantum yields of SbVPor showed a tendency to be increased by the complex formation with Clay. The less cationic SbVPor/Clay complex showed the larger fluorescence quantum yield. The m...
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unique photochemical properties of p substituted cationic triphenylbenzene derivatives on a Clay Layer surface
Journal of Physical Chemistry C, 2013Co-Authors: Takamasa Tsukamoto, Tetsuya Shimada, Shinsuke TakagiAbstract:Two types of novel tricationic 1,3,5-triphenylbenzene (TPB) derivatives were synthesized. The TPB derivatives are 1,3,5-tris(N,N,N-trimethylanilinium-4-yl)benzene (TMAB) and 1,3,5-tris[(N-pyridinium)aniline-4-yl]benzene (TPAB). The photochemical behaviors of both cationic TPBs with and without Clay were examined in aqueous solution. For both TPBs, the aggregation behavior was not observed in the Clay complexes even at saturated adsorption conditions. Interestingly, the fluorescence intensity of TPAB was extremely increased by the complex formation with Clay compared to that without Clay in a bulk aqueous solution, although the increase of fluorescence was not observed for TMAB. Time-resolved fluorescence measurement revealed that the increase of fluorescence turned out to be due to the suppression of the nonradiative deactivation process from its excited singlet state, because the molecular motion of TPAB should be restricted due to the strong fixation on the Clay surface. TPAB exhibited a little self-flu...
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high density adsorption of cationic porphyrins on Clay Layer surfaces without aggregation the size matching effect
Langmuir, 2002Co-Authors: Shinsuke Takagi, Tetsuya Shimada, Miharu Eguchi, Tatsuto Yui, Hirohisa Yoshida, And Donald A Tryk, Haruo InoueAbstract:Several inorganic−organic hybrid complexes were synthesized from a synthetic Clay (Sumecton SA) and cationic porphyrins (+4 charge). In the Clay−porphyrin complexes, the λmax values of the Soret bands of the porphyrins were shifted to longer wavelengths compared to those in water. Two types of complexes were formed depending on the preparation method. One is assigned to a complex in which the porphyrin molecules are adsorbed on the external surfaces of the dispersed Clay Layers (type b complexes). The other is assigned to a complex in which the porphyrin molecules are intercalated within the stacked Clay Layers (type c complexes). The aqueous solutions of both types of complexes do not scatter light in the UV−visible wavelength region. Surprisingly, the porphyrin molecules were found to adsorb on the Clay sheets as densely packed monoLayers with controlled intermolecular gap distance. In type b, the porphyrins are adsorbed as flat monoLayers, without discernible aggregation, that precisely neutralize the ...
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high density adsorption of porphyrins onto Clay Layer without aggregation characterization of smectite cationic porphyrin complex
Chemistry Letters, 2001Co-Authors: Shinsuke Takagi, Tetsuya Shimada, Tatsuto Yui, Haruo InoueAbstract:Adsorption of the +4 charged cationic porphyrins onto an artificially synthesized smectite was studied. Porphyrin molecules adsorb on the Clay sheet with high density to neutralize all the minus charges of the Clay surface without aggregation by a novel method of a size-matching of distances between the charge sites. An efficient energy transfer between different porphyrins was induced on the Clay surface, while there was no interaction in the ground state.
Alireza Salehi - One of the best experts on this subject based on the ideXlab platform.
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cone penetration test in stiff over soft Clay in centrifuge test
ASME 2019 38th International Conference on Ocean Offshore and Arctic Engineering OMAE 2019, 2019Co-Authors: Yuxia Hu, Mark Cassidy, Alireza SalehiAbstract:This paper describes a numerical study on soil characterization of stiff over soft Clays in centrifuge test using cone penetration test (CPT), especially when the top stiff Layer is thin relative to the centrifuge cone size. An extensive parametric study was conducted using large deformation finite element (LDFE) analysis, with the cone penetrating continuously from the soil surface. The LDFE model has been validated against existing physical test data with very good agreement. Since the bottom soft Clay was normally thick enough to fully mobilise the ultimate cone resistance, its undrained shear strength can be interpreted by the existing approach for cone deep penetration in a uniform Clay Layer. Thus, the challenge was to interpret the strength of the top stiff Layer, where the Layer thickness was not thick enough to fully mobilise its ultimate resistance. Both top Layer thickness ratios (to the cone diameter) and Layer strength ratios were considered in the parametric study. Based on the results from LDFE analyses, the interpretation formula of the undrained shear strength in the top stiff Layer was proposed as a set of new bearing factors. The proposed cone bearing factor was a function of the ratio of the measured peak cone resistance in the top Layer to the stable/ultimate cone resistance in the bottom Layer and the ratio between the top Layer thickness to the cone diameter. The formula can be used directly when the top Layer thickness was known based on the sample preparation. However, the Layer interface can be identified based on the study here, if the top Layer thickness was not certain. A design flow chart was provided for interpretations of top Clay Layer strength and top Layer thickness based on the cone resistance profile obtained from CPT test.
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cone penetration test in stiff over soft Clay in centrifuge test
ASME 2019 38th International Conference on Ocean Offshore and Arctic Engineering OMAE 2019, 2019Co-Authors: Yuxia Hu, Mark Cassidy, Alireza SalehiAbstract:This paper describes a numerical study on soil characterization of stiff over soft Clays in centrifuge test using cone penetration test (CPT), especially when the top stiff Layer is thin relative to the centrifuge cone size. An extensive parametric study was conducted using large deformation finite element (LDFE) analysis, with the cone penetrating continuously from the soil surface. The LDFE model has been validated against existing physical test data with very good agreement. Since the bottom soft Clay was normally thick enough to fully mobilise the ultimate cone resistance, its undrained shear strength can be interpreted by the existing approach for cone deep penetration in a uniform Clay Layer. Thus, the challenge was to interpret the strength of the top stiff Layer, where the Layer thickness was not thick enough to fully mobilise its ultimate resistance. Both top Layer thickness ratios (to the cone diameter) and Layer strength ratios were considered in the parametric study. Based on the results from LDFE analyses, the interpretation formula of the undrained shear strength in the top stiff Layer was proposed as a set of new bearing factors. The proposed cone bearing factor was a function of the ratio of the measured peak cone resistance in the top Layer to the stable/ultimate cone resistance in the bottom Layer and the ratio between the top Layer thickness to the cone diameter. The formula can be used directly when the top Layer thickness was known based on the sample preparation. However, the Layer interface can be identified based on the study here, if the top Layer thickness was not certain. A design flow chart was provided for interpretations of top Clay Layer strength and top Layer thickness based on the cone resistance profile obtained from CPT test.
Chaosheng Tang - One of the best experts on this subject based on the ideXlab platform.
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discrete element modelling of desiccation cracking in thin Clay Layer under different basal boundary conditions
Computers and Geotechnics, 2021Co-Authors: Zhuyuan Lin, Chaosheng Tang, Yishu Wang, Qing Cheng, Hao Zeng, Chun Liu, Bin ShiAbstract:Abstract This study aims to investigate the effect of basal boundary conditions on the initiation and propagation of desiccation cracking along the vertical direction in thin Clay Layer using discrete element method (DEM). A two-dimensional discrete model was proposed considering shrinkage kinetics and property change during the drying process. Different basal boundary constraints were simulated by applying bond between the soil particles and the fixed base particles of difference sizes. The simulation results were compared with the laboratory experiments. The results showed that the model can reproduce the main trend of desiccation process. Larger base particles produced more cracks in the specimen. Both cracks initiated from the top surface and cracks initiated from the bottom soil-base interface were observed and discriminated in the simulation. The model revealed the development of bottom-initiated cracks and unpenetrated cracks beneath the surface that may be neglected in traditional cracking simulations. The study suggests that the different initiation position of cracks is associated with the change of force distribution inside the specimen. Moreover, the effects of different boundary properties (the geometrical roughness, the frictional coefficient and the bond strength), particle density change and evaporation gradient on model performance were investigated.
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desiccation and cracking behaviour of Clay Layer from slurry state under wetting drying cycles
Geoderma, 2011Co-Authors: Chaosheng Tang, Anh Minh TangAbstract:Laboratory tests were conducted to investigate the effect of wetting-drying (W-D) cycles on the initiation and evolution of cracks in Clay Layer. Four identical slurry specimens were prepared and subjected to five subsequent W-D cycles. The water evaporation, surface cracks evolution and structure evolution during the W-D cycles were monitored. The effect of W-D cycles on the geometric characteristics of crack patterns was analyzed by image processing. The results show that the desiccation and cracking behaviour was significantly affected by the applied W-D cycles: the measured cracking water content c, surface crack ratio Rsc and final thickness hf of the specimen increased significantly in the first three W-D cycles and then tended to reach equilibrium; the formed crack patterns after the second W-D cycle were more irregular than that after the first W-D cycle; the increase of surface cracks was accompanied by the decrease of pore volume shrinkage during drying. In addition, it was found that the applied W-D cycles resulted in significant rearrangement of specimen structure: the initially homogeneous and non-aggregated structure was converted to a clear aggregated-structure with obvious inter-aggregate pores after the second W-D cycle; the specimen volume generally increased with increasing cycles due to the aggregation and increased porosity. The image analysis results show that the geometric characteristics of crack pattern were significantly influenced by the W-D cycles, but this influence was reduced after the third cycle. This is consistent with the observations over the experiment, and indicates that the image processing can be used for quantitatively analyzing the W-D cycle dependence of Clay desiccation cracking behaviour.
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experimental characterization of shrinkage and desiccation cracking in thin Clay Layer
Applied Clay Science, 2011Co-Authors: Chaosheng TangAbstract:Abstract Knowledge of shrinkage mechanism and the accompanied cracking behavior is helpful for better understanding the hydraulic and mechanical performance of Clay soil under atmosphere condition. Initially saturated thin Clay Layers were prepared and subjected to air drying in this investigation. Water evaporation, volume shrinkage, surface crack initiation and propagation processes were monitored during the whole drying period. With application of image processing technique, the geometric or morphological characteristics of crack patterns were quantitatively described. Results show that the water in the Clay Layer evaporated at a near constant rate and then it began to decline when the water content was close to the air entry value. The Clay Layer volume shrinkage was contributed completely by vertical subsidence before desiccation crack initiation, and the measured final vertical shrinkage strain was several times higher than the lateral shrinkage strain. In addition, it was found that most of the cracks and volume shrinkage occurred during the constant rate of evaporation period while the specimen was still saturated. Crack initiation and propagation generally took place in three stages and terminated at the shrinkage limit. During the process of crack propagation, the crack intersections reached a stable value first and were followed by crack length and crack width.
Tetsuya Shimada - One of the best experts on this subject based on the ideXlab platform.
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photochemical properties of mono tri and penta cationic antimony v metalloporphyrin derivatives on a Clay Layer surface
Journal of Physical Chemistry A, 2013Co-Authors: Takamasa Tsukamoto, Tetsuya Shimada, Shinsuke TakagiAbstract:Three types of mono-, tri-, and penta-cationic antimony(V) porphyrin derivatives (SbVPors) were synthesized, and their photochemical properties on the anionic Clay were systematically investigated. SbVPor derivatives are dihydroxo(5,10,15,20-tetraphenylporphyrinato)antimony(V) chloride ([SbV(TPP)(OH)2]+Cl–), dihydroxo[5,10-diphenyl-15,20-di(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) trichloride ([SbV(DMPyP)(OH)2]3+3Cl–), and dihydroxo[5,10,15,20-tetrakis(N-methyl-pyridinium-4-yl)porphyrinato]antimony(V) pentachloride ([SbV(TMPyP)(OH)2]5+5Cl–). The photochemical behaviors of three cationic SbVPors with and without Clay were examined in aqueous solution. For all SbVPor, aggregation behaviors were not observed in the Clay complexes even at high density adsorption conditions. The transition probabilities and fluorescence quantum yields of SbVPor showed a tendency to be increased by the complex formation with Clay. The less cationic SbVPor/Clay complex showed the larger fluorescence quantum yield. The m...
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unique photochemical properties of p substituted cationic triphenylbenzene derivatives on a Clay Layer surface
Journal of Physical Chemistry C, 2013Co-Authors: Takamasa Tsukamoto, Tetsuya Shimada, Shinsuke TakagiAbstract:Two types of novel tricationic 1,3,5-triphenylbenzene (TPB) derivatives were synthesized. The TPB derivatives are 1,3,5-tris(N,N,N-trimethylanilinium-4-yl)benzene (TMAB) and 1,3,5-tris[(N-pyridinium)aniline-4-yl]benzene (TPAB). The photochemical behaviors of both cationic TPBs with and without Clay were examined in aqueous solution. For both TPBs, the aggregation behavior was not observed in the Clay complexes even at saturated adsorption conditions. Interestingly, the fluorescence intensity of TPAB was extremely increased by the complex formation with Clay compared to that without Clay in a bulk aqueous solution, although the increase of fluorescence was not observed for TMAB. Time-resolved fluorescence measurement revealed that the increase of fluorescence turned out to be due to the suppression of the nonradiative deactivation process from its excited singlet state, because the molecular motion of TPAB should be restricted due to the strong fixation on the Clay surface. TPAB exhibited a little self-flu...
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high density adsorption of cationic porphyrins on Clay Layer surfaces without aggregation the size matching effect
Langmuir, 2002Co-Authors: Shinsuke Takagi, Tetsuya Shimada, Miharu Eguchi, Tatsuto Yui, Hirohisa Yoshida, And Donald A Tryk, Haruo InoueAbstract:Several inorganic−organic hybrid complexes were synthesized from a synthetic Clay (Sumecton SA) and cationic porphyrins (+4 charge). In the Clay−porphyrin complexes, the λmax values of the Soret bands of the porphyrins were shifted to longer wavelengths compared to those in water. Two types of complexes were formed depending on the preparation method. One is assigned to a complex in which the porphyrin molecules are adsorbed on the external surfaces of the dispersed Clay Layers (type b complexes). The other is assigned to a complex in which the porphyrin molecules are intercalated within the stacked Clay Layers (type c complexes). The aqueous solutions of both types of complexes do not scatter light in the UV−visible wavelength region. Surprisingly, the porphyrin molecules were found to adsorb on the Clay sheets as densely packed monoLayers with controlled intermolecular gap distance. In type b, the porphyrins are adsorbed as flat monoLayers, without discernible aggregation, that precisely neutralize the ...
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high density adsorption of porphyrins onto Clay Layer without aggregation characterization of smectite cationic porphyrin complex
Chemistry Letters, 2001Co-Authors: Shinsuke Takagi, Tetsuya Shimada, Tatsuto Yui, Haruo InoueAbstract:Adsorption of the +4 charged cationic porphyrins onto an artificially synthesized smectite was studied. Porphyrin molecules adsorb on the Clay sheet with high density to neutralize all the minus charges of the Clay surface without aggregation by a novel method of a size-matching of distances between the charge sites. An efficient energy transfer between different porphyrins was induced on the Clay surface, while there was no interaction in the ground state.
Yuxia Hu - One of the best experts on this subject based on the ideXlab platform.
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cone penetration test in stiff over soft Clay in centrifuge test
ASME 2019 38th International Conference on Ocean Offshore and Arctic Engineering OMAE 2019, 2019Co-Authors: Yuxia Hu, Mark Cassidy, Alireza SalehiAbstract:This paper describes a numerical study on soil characterization of stiff over soft Clays in centrifuge test using cone penetration test (CPT), especially when the top stiff Layer is thin relative to the centrifuge cone size. An extensive parametric study was conducted using large deformation finite element (LDFE) analysis, with the cone penetrating continuously from the soil surface. The LDFE model has been validated against existing physical test data with very good agreement. Since the bottom soft Clay was normally thick enough to fully mobilise the ultimate cone resistance, its undrained shear strength can be interpreted by the existing approach for cone deep penetration in a uniform Clay Layer. Thus, the challenge was to interpret the strength of the top stiff Layer, where the Layer thickness was not thick enough to fully mobilise its ultimate resistance. Both top Layer thickness ratios (to the cone diameter) and Layer strength ratios were considered in the parametric study. Based on the results from LDFE analyses, the interpretation formula of the undrained shear strength in the top stiff Layer was proposed as a set of new bearing factors. The proposed cone bearing factor was a function of the ratio of the measured peak cone resistance in the top Layer to the stable/ultimate cone resistance in the bottom Layer and the ratio between the top Layer thickness to the cone diameter. The formula can be used directly when the top Layer thickness was known based on the sample preparation. However, the Layer interface can be identified based on the study here, if the top Layer thickness was not certain. A design flow chart was provided for interpretations of top Clay Layer strength and top Layer thickness based on the cone resistance profile obtained from CPT test.
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cone penetration test in stiff over soft Clay in centrifuge test
ASME 2019 38th International Conference on Ocean Offshore and Arctic Engineering OMAE 2019, 2019Co-Authors: Yuxia Hu, Mark Cassidy, Alireza SalehiAbstract:This paper describes a numerical study on soil characterization of stiff over soft Clays in centrifuge test using cone penetration test (CPT), especially when the top stiff Layer is thin relative to the centrifuge cone size. An extensive parametric study was conducted using large deformation finite element (LDFE) analysis, with the cone penetrating continuously from the soil surface. The LDFE model has been validated against existing physical test data with very good agreement. Since the bottom soft Clay was normally thick enough to fully mobilise the ultimate cone resistance, its undrained shear strength can be interpreted by the existing approach for cone deep penetration in a uniform Clay Layer. Thus, the challenge was to interpret the strength of the top stiff Layer, where the Layer thickness was not thick enough to fully mobilise its ultimate resistance. Both top Layer thickness ratios (to the cone diameter) and Layer strength ratios were considered in the parametric study. Based on the results from LDFE analyses, the interpretation formula of the undrained shear strength in the top stiff Layer was proposed as a set of new bearing factors. The proposed cone bearing factor was a function of the ratio of the measured peak cone resistance in the top Layer to the stable/ultimate cone resistance in the bottom Layer and the ratio between the top Layer thickness to the cone diameter. The formula can be used directly when the top Layer thickness was known based on the sample preparation. However, the Layer interface can be identified based on the study here, if the top Layer thickness was not certain. A design flow chart was provided for interpretations of top Clay Layer strength and top Layer thickness based on the cone resistance profile obtained from CPT test.