In this study on the nature of pressure signals generated by a deterministic or stochastic process in a bubbling fluidized bed, pressure fluctuation measurements were carried out in a 300-mm-diamet column at 0.090 m...In this study on the nature of pressure signals generated by a deterministic or stochastic process in a bubbling fluidized bed, pressure fluctuation measurements were carried out in a 300-mm-diamet column at 0.090 m and 0.40 m above the distributor for different gas velocities. The method of detecting deterministic dynamic underlying pressure signals is proposed on the basis of predictability of pressure fluctuations. The deterministic nature of dynamics in fluidizing system was verified. The deterministic level of dynamics in fluidizing system was analyzed for different locations of pressure measurements and different gas velocities.展开更多
An experimental verification is reported on the early predicting index of agglomeration in bubbling fluidized bed. Coarse quartz sand, which has the same density but larger diameter than the bed material, was used to ...An experimental verification is reported on the early predicting index of agglomeration in bubbling fluidized bed. Coarse quartz sand, which has the same density but larger diameter than the bed material, was used to simulate the initial agglomerated particle. Wigner distribution was used to analyze the pressure fuctuation of the tested bed, and the average amplitude of local domain frequency （LDF） and local peak weighted average frequency （LPWA） under different operating conditions were measured and compared. The results showed that the LDF is sensitive to the agglomeration phenomena and had quick response to the incipient agglomeration in fluidized beds. It can be concluded from the results that these two parameters could be taken as the characteristic indexes to the agglomeration in fuidized beds.展开更多
It has been shown that much dynamic information is hidden in the pressure fluctuation signals of a gas-solid fluidized bed. Unfortunately, due to the random and capricious nature of this signal, it is hard to realize ...It has been shown that much dynamic information is hidden in the pressure fluctuation signals of a gas-solid fluidized bed. Unfortunately, due to the random and capricious nature of this signal, it is hard to realize reliable analysis using traditional signal processing methods such as statistical analysis or spectral analysis, which is done in Fourier domain. Information in different frequency band can be extracted by using wavelet analysis. On the evidence of the composition of the pressure fluctuation signals, energy of low frequency (ELF) is proposed to show the transition of fluidized regimes from bubbling fluidization to turbulent fluidization. Plots are presented to describe the fluidized bed's evolution to help identify the state of different flow regimes and provide a characteristic curve to identify the fluidized status effectively and reliably.展开更多
This article reviews recent advances in surgical techniques and adjuvant therapies for colorectal cancer, including total mesorectal excision, the resection of liver and lung metastasis and advances in chemoradiation ...This article reviews recent advances in surgical techniques and adjuvant therapies for colorectal cancer, including total mesorectal excision, the resection of liver and lung metastasis and advances in chemoradiation and foreshadows some interventions that may lie just beyond the frontier. In particular, little is known about the intracellular and extracellular cascades that may influence colorectal cancer cell adhesion and metastasis. Although the phosphorylation of focal adhesion kinases and focal adhesion associated proteins in response to integrin-mediated cell matrix binding ("outside in integrin signaling") is well described, the stimulation of cell adhesion by intracellular signals activated by pressure prior to adhesion represents a different signal paradigm. However, several studies have suggested that increased pressure and shear stress activate cancer cell adhesion. Further studies of the pathways that regulate integrin-driven cancer cell adhesion may identify ways to disrupt these signals or block integrin-mediated adhesion so that adhesion and eventual metastasis can be prevented in the future.展开更多
文摘In this study on the nature of pressure signals generated by a deterministic or stochastic process in a bubbling fluidized bed, pressure fluctuation measurements were carried out in a 300-mm-diamet column at 0.090 m and 0.40 m above the distributor for different gas velocities. The method of detecting deterministic dynamic underlying pressure signals is proposed on the basis of predictability of pressure fluctuations. The deterministic nature of dynamics in fluidizing system was verified. The deterministic level of dynamics in fluidizing system was analyzed for different locations of pressure measurements and different gas velocities.
文摘An experimental verification is reported on the early predicting index of agglomeration in bubbling fluidized bed. Coarse quartz sand, which has the same density but larger diameter than the bed material, was used to simulate the initial agglomerated particle. Wigner distribution was used to analyze the pressure fuctuation of the tested bed, and the average amplitude of local domain frequency （LDF） and local peak weighted average frequency （LPWA） under different operating conditions were measured and compared. The results showed that the LDF is sensitive to the agglomeration phenomena and had quick response to the incipient agglomeration in fluidized beds. It can be concluded from the results that these two parameters could be taken as the characteristic indexes to the agglomeration in fuidized beds.
文摘It has been shown that much dynamic information is hidden in the pressure fluctuation signals of a gas-solid fluidized bed. Unfortunately, due to the random and capricious nature of this signal, it is hard to realize reliable analysis using traditional signal processing methods such as statistical analysis or spectral analysis, which is done in Fourier domain. Information in different frequency band can be extracted by using wavelet analysis. On the evidence of the composition of the pressure fluctuation signals, energy of low frequency (ELF) is proposed to show the transition of fluidized regimes from bubbling fluidization to turbulent fluidization. Plots are presented to describe the fluidized bed's evolution to help identify the state of different flow regimes and provide a characteristic curve to identify the fluidized status effectively and reliably.
文摘This article reviews recent advances in surgical techniques and adjuvant therapies for colorectal cancer, including total mesorectal excision, the resection of liver and lung metastasis and advances in chemoradiation and foreshadows some interventions that may lie just beyond the frontier. In particular, little is known about the intracellular and extracellular cascades that may influence colorectal cancer cell adhesion and metastasis. Although the phosphorylation of focal adhesion kinases and focal adhesion associated proteins in response to integrin-mediated cell matrix binding ("outside in integrin signaling") is well described, the stimulation of cell adhesion by intracellular signals activated by pressure prior to adhesion represents a different signal paradigm. However, several studies have suggested that increased pressure and shear stress activate cancer cell adhesion. Further studies of the pathways that regulate integrin-driven cancer cell adhesion may identify ways to disrupt these signals or block integrin-mediated adhesion so that adhesion and eventual metastasis can be prevented in the future.
