The biointerface dynamics influence any cancer spreading through the epithelium since it is documented in the early stages some malignancies(like epithelial cancer).The altered rearrangement of epithelial cells has an...The biointerface dynamics influence any cancer spreading through the epithelium since it is documented in the early stages some malignancies(like epithelial cancer).The altered rearrangement of epithelial cells has an impact on the development of cancer.Therefore,it is necessary to comprehend the underlying biological and physical mechanisms of this biointerface dynamics for early suppression of cancer.While the biological mechanisms include cell signaling and gene expression,the physical mechanisms are several physical parameters such as the epithelial-cancer interfacial tension,epithelial surface tension,and compressive stress accumulated within the epithelium.Although the segregation of epithelia-cancer co-cultured systems was widely investigated,the role of these physical parameters in cell reorganization is still not fully recognized.Hence,this review is focused on clarifying the role that some physical parameters have during cell reorganization within the epithelial cell clusters and cancer spread within co-cultured spheroids.We have applied the developed biophysical model to point out the inter-relations among physical parameters that influence cell reorganization within epithelial-cancer co-cultured systems.The main results of this theoretical consideration have been assessed by integrating the biophysical model with biological and bio-mechanical experiments from the available literature.The epithelial-cancer interfacial tension leads to the reduction of the biointerface area,which leads to an increase in the compressive residual stress within the epithelial clusters depending on the viscoelasticity of the epithelial subpopulation.This stress impacts epithelial rearrangement and the dynamics along the biointerface by influencing the epithelial surface tension and epithelial-cancer interfacial tension.Further,the interrelation between the epithelial surface tension and epithelial-cancer interfacial tension influences the spread of cancer cells.展开更多
Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room tempe...Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.展开更多
The dissolution behavior of rI phase has been investigated in a cast Ni-based superalloy. The results showed that the platelets and blocks of η phase were formed within the interdendritic regions of the microstructur...The dissolution behavior of rI phase has been investigated in a cast Ni-based superalloy. The results showed that the platelets and blocks of η phase were formed within the interdendritic regions of the microstructure. Applying standard solution annealing at 1150-1160℃ for a period of 4 h did not result in the complete dissolution of η phase. For the complete dissolution of η phase without residual incipient melting, a 2-step solution annealing has been recommended. After dissolution at high tem- peratures, the TI phase transforms to two MC-type carbides： one is enriched in Ti, Nb, and Ta, and the other is of （Zr,Ti）C type.展开更多
The friction performance of the polyimide （PI） porous composite materials made by moulding method with MoS2 or polytetrafluoroethylene （PTFE） appended are disserted. The result shows that all the PI-based porous c...The friction performance of the polyimide （PI） porous composite materials made by moulding method with MoS2 or polytetrafluoroethylene （PTFE） appended are disserted. The result shows that all the PI-based porous composites have the performance of transfer lubrication in the friction process, and the transfer film is built between the counter friction bodies; with the increasing of the MoS2 amount from 0 to 2096, the friction coefficient trends toward decrease, and the transfer lubricate phenomenon become more obvious; when adding PTFE as synergist to the porous PI ＋ MoS2 composite material, the synergistic effect happens, which can improve the friction performance of the material effectively.展开更多
The application of a heat flow model to describe the thermal characteristics of freezing alloys with narrow mushy zones from a refrigerated mould wall was outlined. The extension of the model was to treat the continuo...The application of a heat flow model to describe the thermal characteristics of freezing alloys with narrow mushy zones from a refrigerated mould wall was outlined. The extension of the model was to treat the continuous casting of metals with low thermal conductivity, such as steels, which will be outlined. The model was based on the mathematical expedient for replacing thermal resistance of the metal/mould interface by virtual adjuncts of metal/mould material. It provided a good description of the pool profile and the technique exhibits advantages in terms of both computation and versatility of application.展开更多
In the present work, the surface characteristics of Electrical Discharge Machined (EDM) Al (6351)eSiC and Al (6351)eSiCeB4C composites are investigated. The composites are prepared by employing the conventional stir c...In the present work, the surface characteristics of Electrical Discharge Machined (EDM) Al (6351)eSiC and Al (6351)eSiCeB4C composites are investigated. The composites are prepared by employing the conventional stir casting technique, as it can produce better particle dispersion in the matrix. The detailed experimental study is performed on the composites by varying current (I), duty factor (t), pulse on time (Ton), and the gap voltage (V) in order to analyze the Heat Affected Zone (HAZ) formed in the sub surface and the average crater diameter formed on the machined surface of the composites as an output function. The formation of recast layers, presence of bubbles and the surface texture of the composites at various machining conditions are observed. The results show that the increased Metal Removal Rate (MRR) increases the depth of HAZ and the average crater diameter on the machined area. Further, the addition of B4C particles to the composite produces more surface defect than the AleSiC composite.展开更多
The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. Friction stir processing(FSP) was applied in severe conditions to o...The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. Friction stir processing(FSP) was applied in severe conditions to obtain fine, equiaxed and highly misoriented grains, with grain sizes even less than 1 μm. The high severity of processing demonstrated to have a strong impact in the microstructure. Consequently,the processed materials exhibited excellent superplasticity at the high strain rate 10^(-2)s^(-1), and temperatures between 300 and 400 ℃. The maximum tensile superplastic elongation of 756% was achieved at 400 ℃ thanks to the operation of grain boundary sliding mechanism(GBS). Besides the new data obtained through tensile testing, the paper deals with a transcendental question regarding the large differences in strain rate values at a given stress in the superplastic regime at maximum elongation compared to other magnesium-based alloys. With this is mind, 19 magnesium alloys from 22 different investigations were analyzed to give some light to this behavior that never was treated before. It is proposed that this behavior has to be attributed to the accommodation process, necessary for GBS to occur, which is hindered by reinforcing solutes.展开更多
Friction-wear properties of the ZrSiO4 reinforced samples were measured and compared with those of plain bronze based ones. For this purpose, density, hardness, friction coefficient wear behaviour of the samples were ...Friction-wear properties of the ZrSiO4 reinforced samples were measured and compared with those of plain bronze based ones. For this purpose, density, hardness, friction coefficient wear behaviour of the samples were tested. Microstructures of samples before and after sintering and worn surfaces were also investigated by scanning electron microscopy （SEM）, and the wear types were determined. The optimum friction-wear behaviour was obtained in the sample compacted at 500 MPa and sintered at 820℃. Density of the final samples decreased with increasing the amount of reinforcing elements （ZrSiO4） before pre-sintering. However after sintering, there is no change in density of the samples including reinforcing elements （ZrSiO4）. With increasing friction surface temperature, a reduction in the friction coefficient of the samples was observed. However, the highest reductions in the friction coefficients were observed in the as-received samples containing 0. 5% reinforced ZrSiO4. The SEM images of the sample indicated that while bronze-based break lining material without ZrSiO4 showed abrasive wear behaviour, increasing the amount of ZrSiO4 resulted a change in abrasive to adhesive wear mechanism. All samples exhibited friction-wear values, which were within the values shown in SAE-J661 standard. With increasing the amount of reinforcing ZrSiO4, wear resistance of the samples was increased. However samples reinforced with 5% and 6% ZrSiO4 showed the best results.展开更多
This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed th...This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed that the reduction temperature has a significant effect on the volatilization rate of lead and that neither the particle size of the coal powder nor the extra carbon content has any effect on the volatilization rate. The obtained activation energy for the volatilization of lead is 88.74 kJ/mol. The volatilization rate of lead is controlled by both the lead evaporation reaction and the diffusion of gaseous lead through the gas boundary layer covering the surface of the reduced liquid lead.展开更多
Based on a series of experiments, the theory of relationship between normal pressure and pores＇ characters fit for polymer was set up for the first time. On the study of relation between normal pressure and porosity,...Based on a series of experiments, the theory of relationship between normal pressure and pores＇ characters fit for polymer was set up for the first time. On the study of relation between normal pressure and porosity, experience model of polyimide porous materials was proposed which is similar to the traditional expe- rience model of the metal porous material. While being pressed, polyimide was found soon to come into elasto- plastic deformation progress in this paper, so the theory model of metal porous material based on Hooker＇s law was not fit for the polymer any more. A new elasto-plastic deformation and exhausting model is proposed which shows better agreement with polymer material＇s pressing process.展开更多
A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The stu...A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The study shows that the reduction temperature has a significant effect on the volatilization rate of zinc and that either the coal particle size or the excess carbon content has no effect on the volatilization rate. The obtained activation energy for the volatilization of zinc is 79.42 kJ/mol. The volatilization rate of zinc is controlled by the reaction between the zinc oxides and CO.展开更多
Luminescent porous materials have shown various applications such as electronic devices, gas adsorption, energy materials and photocatalysis. Consequently, we designed and prepared a new type borondipyrromethene(BODIP...Luminescent porous materials have shown various applications such as electronic devices, gas adsorption, energy materials and photocatalysis. Consequently, we designed and prepared a new type borondipyrromethene(BODIPY) based porous organic polymer(POP) by using Sonogashira coupling reaction. This POP-1 exhibits high thermal stability with moderate surface area. In addition, POP-1 is highly emissive in a solid state. Due to enrichment of different kinds of heteroatoms in the skeleton of the porous polymer, POP-1 selectively captures carbon dioxide(CO_2) with relative high adsorption selectivity of CO_2/N_2.展开更多
ZrN-based composites were synthesized from zirconia via aluminothermic reduction and nitridation proces with Al powders and Mg O as the reductant and sintering aids,respectively. ZrN-based composites are promising for...ZrN-based composites were synthesized from zirconia via aluminothermic reduction and nitridation proces with Al powders and Mg O as the reductant and sintering aids,respectively. ZrN-based composites are promising for application in the refractory materials or other high temperature industry fields. The effects of extra Al powder on physical properties,phase transformation and microstructures were investigated. Products with differen phase composition and morphologies were obtained with different Al powders additions. The products were composed of Zr N,ZrO2,MgAl2O4,and Zr Al3O3N by aluminothermal reduction and nitridation of zirconia with 0% extra Al powders addition. The diffraction peaks o Zr N were the strongest while peaks of ZrO2vanished with 6% extra Al addition. The thermodynamic calculation indicated that introducing Mg O into the system could promote the reaction process.展开更多
基金supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia(Contract No.451-03-68/2022-14/200135).
文摘The biointerface dynamics influence any cancer spreading through the epithelium since it is documented in the early stages some malignancies(like epithelial cancer).The altered rearrangement of epithelial cells has an impact on the development of cancer.Therefore,it is necessary to comprehend the underlying biological and physical mechanisms of this biointerface dynamics for early suppression of cancer.While the biological mechanisms include cell signaling and gene expression,the physical mechanisms are several physical parameters such as the epithelial-cancer interfacial tension,epithelial surface tension,and compressive stress accumulated within the epithelium.Although the segregation of epithelia-cancer co-cultured systems was widely investigated,the role of these physical parameters in cell reorganization is still not fully recognized.Hence,this review is focused on clarifying the role that some physical parameters have during cell reorganization within the epithelial cell clusters and cancer spread within co-cultured spheroids.We have applied the developed biophysical model to point out the inter-relations among physical parameters that influence cell reorganization within epithelial-cancer co-cultured systems.The main results of this theoretical consideration have been assessed by integrating the biophysical model with biological and bio-mechanical experiments from the available literature.The epithelial-cancer interfacial tension leads to the reduction of the biointerface area,which leads to an increase in the compressive residual stress within the epithelial clusters depending on the viscoelasticity of the epithelial subpopulation.This stress impacts epithelial rearrangement and the dynamics along the biointerface by influencing the epithelial surface tension and epithelial-cancer interfacial tension.Further,the interrelation between the epithelial surface tension and epithelial-cancer interfacial tension influences the spread of cancer cells.
文摘Electrochemical techniques were applied to study the crevice corrosion resistance of two types of stainless steel alloys namely, conventional 316L and 6% Mo super austenitic in acidified 3% NaCl solution at room temperature.Potentiodynamic results showed that 6% Mo alloy possessed a remarkable resistance to crevice corrosion compared with 316L alloy when they are tested in the same solution. The breakdown potential at which passivity broke down for 316L alloy was 0.00 mV （SCE）. The corresponding value for 6% Mo alloy could not reach up to the potential value of 700 mV （SCE）. 316L alloy suffered extremely from crevice corrosion at room temperature （about 25℃）, which indicates that the critical crevice corrosion temperature, below which crevice corrosion does not occur, was lower than the test temperature. For 6% Mo alloy, the critical crevice corrosion temperature was higher than the testing temperature. Electrochemical parameters indicated that 6% Mo alloy exhibited higher crevice corrosion resistance than 316L alloy.
文摘The dissolution behavior of rI phase has been investigated in a cast Ni-based superalloy. The results showed that the platelets and blocks of η phase were formed within the interdendritic regions of the microstructure. Applying standard solution annealing at 1150-1160℃ for a period of 4 h did not result in the complete dissolution of η phase. For the complete dissolution of η phase without residual incipient melting, a 2-step solution annealing has been recommended. After dissolution at high tem- peratures, the TI phase transforms to two MC-type carbides： one is enriched in Ti, Nb, and Ta, and the other is of （Zr,Ti）C type.
文摘The friction performance of the polyimide （PI） porous composite materials made by moulding method with MoS2 or polytetrafluoroethylene （PTFE） appended are disserted. The result shows that all the PI-based porous composites have the performance of transfer lubrication in the friction process, and the transfer film is built between the counter friction bodies; with the increasing of the MoS2 amount from 0 to 2096, the friction coefficient trends toward decrease, and the transfer lubricate phenomenon become more obvious; when adding PTFE as synergist to the porous PI ＋ MoS2 composite material, the synergistic effect happens, which can improve the friction performance of the material effectively.
文摘The application of a heat flow model to describe the thermal characteristics of freezing alloys with narrow mushy zones from a refrigerated mould wall was outlined. The extension of the model was to treat the continuous casting of metals with low thermal conductivity, such as steels, which will be outlined. The model was based on the mathematical expedient for replacing thermal resistance of the metal/mould interface by virtual adjuncts of metal/mould material. It provided a good description of the pool profile and the technique exhibits advantages in terms of both computation and versatility of application.
文摘In the present work, the surface characteristics of Electrical Discharge Machined (EDM) Al (6351)eSiC and Al (6351)eSiCeB4C composites are investigated. The composites are prepared by employing the conventional stir casting technique, as it can produce better particle dispersion in the matrix. The detailed experimental study is performed on the composites by varying current (I), duty factor (t), pulse on time (Ton), and the gap voltage (V) in order to analyze the Heat Affected Zone (HAZ) formed in the sub surface and the average crater diameter formed on the machined surface of the composites as an output function. The formation of recast layers, presence of bubbles and the surface texture of the composites at various machining conditions are observed. The results show that the increased Metal Removal Rate (MRR) increases the depth of HAZ and the average crater diameter on the machined area. Further, the addition of B4C particles to the composite produces more surface defect than the AleSiC composite.
基金Financial support from MINECO (Spain), Project MAT2015–68919-C3–1-R (MINECO/FEDER)CENIM, CSIC, for a contract funded by the aforementioned projectMINECO for a FPI fellowship, number BES2013–063963 (MINECO/FEDER/ESF)。
文摘The coarse-grained WE54 magnesium alloy was heat treated in order to have minimum hardness minimizing the effects of precipitates and solid solution. Friction stir processing(FSP) was applied in severe conditions to obtain fine, equiaxed and highly misoriented grains, with grain sizes even less than 1 μm. The high severity of processing demonstrated to have a strong impact in the microstructure. Consequently,the processed materials exhibited excellent superplasticity at the high strain rate 10^(-2)s^(-1), and temperatures between 300 and 400 ℃. The maximum tensile superplastic elongation of 756% was achieved at 400 ℃ thanks to the operation of grain boundary sliding mechanism(GBS). Besides the new data obtained through tensile testing, the paper deals with a transcendental question regarding the large differences in strain rate values at a given stress in the superplastic regime at maximum elongation compared to other magnesium-based alloys. With this is mind, 19 magnesium alloys from 22 different investigations were analyzed to give some light to this behavior that never was treated before. It is proposed that this behavior has to be attributed to the accommodation process, necessary for GBS to occur, which is hindered by reinforcing solutes.
文摘Friction-wear properties of the ZrSiO4 reinforced samples were measured and compared with those of plain bronze based ones. For this purpose, density, hardness, friction coefficient wear behaviour of the samples were tested. Microstructures of samples before and after sintering and worn surfaces were also investigated by scanning electron microscopy （SEM）, and the wear types were determined. The optimum friction-wear behaviour was obtained in the sample compacted at 500 MPa and sintered at 820℃. Density of the final samples decreased with increasing the amount of reinforcing elements （ZrSiO4） before pre-sintering. However after sintering, there is no change in density of the samples including reinforcing elements （ZrSiO4）. With increasing friction surface temperature, a reduction in the friction coefficient of the samples was observed. However, the highest reductions in the friction coefficients were observed in the as-received samples containing 0. 5% reinforced ZrSiO4. The SEM images of the sample indicated that while bronze-based break lining material without ZrSiO4 showed abrasive wear behaviour, increasing the amount of ZrSiO4 resulted a change in abrasive to adhesive wear mechanism. All samples exhibited friction-wear values, which were within the values shown in SAE-J661 standard. With increasing the amount of reinforcing ZrSiO4, wear resistance of the samples was increased. However samples reinforced with 5% and 6% ZrSiO4 showed the best results.
基金financially supported by the "Joint Fund(project number U1260202)for Iron and Steel Research"built by the National Natural Science Foundation of China and Baosteel Group Corporation
文摘This study investigated the volatilization kinetics of lead in pellets made of Zn-Pb-bearing dusts mixed with coal powder,in a nitrogen atmosphere and in the temperature range between 1 100 ℃ - 1 300℃ ,and showed that the reduction temperature has a significant effect on the volatilization rate of lead and that neither the particle size of the coal powder nor the extra carbon content has any effect on the volatilization rate. The obtained activation energy for the volatilization of lead is 88.74 kJ/mol. The volatilization rate of lead is controlled by both the lead evaporation reaction and the diffusion of gaseous lead through the gas boundary layer covering the surface of the reduced liquid lead.
文摘Based on a series of experiments, the theory of relationship between normal pressure and pores＇ characters fit for polymer was set up for the first time. On the study of relation between normal pressure and porosity, experience model of polyimide porous materials was proposed which is similar to the traditional expe- rience model of the metal porous material. While being pressed, polyimide was found soon to come into elasto- plastic deformation progress in this paper, so the theory model of metal porous material based on Hooker＇s law was not fit for the polymer any more. A new elasto-plastic deformation and exhausting model is proposed which shows better agreement with polymer material＇s pressing process.
文摘A study was carried out on the volatilization kinetics of Zn in the pellets made of Zn-bearing dusts mixed with coal powder in a nitrogen atmosphere and within the temperature range between 1 100℃and 1 300℃. The study shows that the reduction temperature has a significant effect on the volatilization rate of zinc and that either the coal particle size or the excess carbon content has no effect on the volatilization rate. The obtained activation energy for the volatilization of zinc is 79.42 kJ/mol. The volatilization rate of zinc is controlled by the reaction between the zinc oxides and CO.
基金Funded by the Natural Science Foundation of China(Nos.21674129 and 21376272)the Post-doctor Foundation of Central South University(No.140050292)
文摘Luminescent porous materials have shown various applications such as electronic devices, gas adsorption, energy materials and photocatalysis. Consequently, we designed and prepared a new type borondipyrromethene(BODIPY) based porous organic polymer(POP) by using Sonogashira coupling reaction. This POP-1 exhibits high thermal stability with moderate surface area. In addition, POP-1 is highly emissive in a solid state. Due to enrichment of different kinds of heteroatoms in the skeleton of the porous polymer, POP-1 selectively captures carbon dioxide(CO_2) with relative high adsorption selectivity of CO_2/N_2.
基金supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia under the research project: “Electrochemical synthesis and characterization of nanostructured functional materials for application in new technologies” (Project No. 172046)
文摘ZrN-based composites were synthesized from zirconia via aluminothermic reduction and nitridation proces with Al powders and Mg O as the reductant and sintering aids,respectively. ZrN-based composites are promising for application in the refractory materials or other high temperature industry fields. The effects of extra Al powder on physical properties,phase transformation and microstructures were investigated. Products with differen phase composition and morphologies were obtained with different Al powders additions. The products were composed of Zr N,ZrO2,MgAl2O4,and Zr Al3O3N by aluminothermal reduction and nitridation of zirconia with 0% extra Al powders addition. The diffraction peaks o Zr N were the strongest while peaks of ZrO2vanished with 6% extra Al addition. The thermodynamic calculation indicated that introducing Mg O into the system could promote the reaction process.
