Cigarette smoke is harmful to human health at both cellular and genetic levels. Recently, a uniqu... more Cigarette smoke is harmful to human health at both cellular and genetic levels. Recently, a unique bioassay for smoke cytotoxicity using air pollution-sensitive plant cells (tobacco) has been proposed. Model plant cells (tobacco Bel-W3 cells) and human cells (alveolar epithelial A549 cells) suspended in fresh culture media were exposed to cigarette smoke sampled after lighting the tip of cigarettes (with vs. without menthol capsules) which were attached to a glass pipe connected to the cell-containing plastic tubes. Control cultures were also assessed. After exposing tobacco plant cells to cigarette smoke, cell death occurred in a dose-dependent manner. Cell death was significantly enhanced by mentholated smoke, while menthol alone was shown to be inert suggesting that menthol synergistically contributes to the enhancement of cell death, initiated by smoke-associated compounds. The enhanced toxicity of mentholated smoke was confirmed in human alveolar epithelial A549 cells. Cigarette smoke cytotoxicity leading to cell death assessed in plant and human model cells was enhanced by menthol. Further research into these findings is encouraged.
ABSTRACT The pulsating flame spread over liquid fuels consists of main-pulsation with 0.5 to 2 Hz... more ABSTRACT The pulsating flame spread over liquid fuels consists of main-pulsation with 0.5 to 2 Hz frequency and sub-pulsation with 5 to 10 Hz frequency. The former originates in existence of a cold temperature valley at the liquid surface ahead of the spreading flame. The cold temperature valley is formed by the surface wave in connection with a sub-surface layer circulation. In this study, the instability analysis for the liquid surface ahead of a flame leading edge was performed to clarify the onset of surface wave. Moreover the effect of gravity on surface wave generation was examined. The theoretical result shows that the onset of surface wave is firstly controlled by Marangoni force and secondary by buoyancy force. The critical condition for onset of surface wave was expressed to the non-dimensional form. Three dimensionless parameters, the Marangoni number, the Weber number and the Froude number include the ratio, ħ/L, of the characteristic length, L, and the depth, ħ, of sub-surface layer circulation (shown in Fig. 1). F1 The circulation scale for seven different thickness of liquid fuel from 2 to 20 mm was measured using a schlieren photograph and thermography. The ratio, ħ/L, decreases with decreasing fuel layer thickness less than 5 mm and consists to μg condition at the fuel layer thickness of 3 mm.
International Journal of Chemical Engineering, 2008
... 1999. T. Konishi, G. Tashtoush, A. Ito, A. Narumi, and K. Saito, The effect of a cold temper... more ... 1999. T. Konishi, G. Tashtoush, A. Ito, A. Narumi, and K. Saito, The effect of a cold temperature valley on pulsating flame spread over propanol, Proceedings of the Combustion Institute, vol. 28, no. 2, pp. 28192826, 2000. ...
Experiments using a particle-track laser sheet technique (PTLS) combined with a high speed video ... more Experiments using a particle-track laser sheet technique (PTLS) combined with a high speed video camera were conducted to reveal the flame structure and flow vector diagram in medium-size pool fires. To improve our understanding of the scale effects on buoyancy controlled flame structure, we employed four different size liquid pool fires whose pan diameters are 10, 20, 30 and 50 cm. These results were compared with numerical analysis previously presented by other researchers. The flow visualization results at the vertical plane along a center axis are in good agreement with numerical results. However, air entrainment through the flame is estimated to be at most 30% larger than that of axis-symmetric smooth flame because of an increase in the reaction surface area and the existing rotational velocity component around the wrinkled flame. For a medium-size pool fire below 20 cm-diameter pan, the flame height and the puffing frequency are close to an assembled small-size pool fire in which 3 cm-diameter pans are lined around a circle. The flame structure below 20 cm-diameter seems to be composed of several flame cells. While the flame structure above 30 cm-diameter is quite different from the aggregate of small-size pool fires. For a 50 cm-diameter pool fire a wrinkled flame having a high frequent disturbance of 12–14 Hz occurs near the base flame zone and grows along the flame surface. A pool fire beyond 50 cm diameter pan becomes a large-scale pool fire having a turbulent flow structure.
Stability and scaling analyses were applied to experimental data obtained by this group and other... more Stability and scaling analyses were applied to experimental data obtained by this group and other researchers on pulsating flame spread over liquids. Data to be analyzed include recent findings of cyclic appearance of a cold temperature valley at the liquid surface-created surface-wave ahead of the spreading flame, and main-pulsation of 0.5–2Hz and sub-pulsation of 5–10Hz. Our stability analysis is performed
ABSTRACT The detailed temperature structure that was created during a pulsating flame spread over... more ABSTRACT The detailed temperature structure that was created during a pulsating flame spread over n-butanol was measured using holographic interferometer, shadowgraph, and IR thermograph techniques. This study found that there was a small surface wave over the previously observed cold-temperature valley located about 10 mm ahead of the spreading flame's leading edge. The newly observed surface wave was located between the spreading flame edge and the cold-temperature valley. The crest of the wave was higher than the quenching distance of the spreading flame. Due to the formation of a small gas-phase circulation cell that was observed to exist between the wave crest and the flame leading edge by laser sheet particle tracking and smoke-tracing techniques, the flammable gas mixture cannot spread beyond the wave crest; therefore, the flame's leading edge was not able to propagate beyond the wave crest. The crawling spread process was believed to be a spread process with constant speed, but this study found that it consists of a small-scale pulsation (subpulsation) with 6–12 Hz frequency. Subpulsation seems likely to have a correlation with the cyclic apperance and disappearance of a small gas-phase circulation cell that travels between the flame edge and the wave crest. When the crawling process provided sufficient heat to the liquid, the cold-temperature valley disappeared. Then the warm liquid helped to form a flammable gas layer over its surface, enabling the flame to propagate through the layer. This is called the “main” pulsating spread, a typically observed pulsating flame-spread phenomenon. This study revealed that a millimeter-order surface wave is responsible for the subpulsation that is responsible for the main pulsating spread. However, the mechanism of surface wave formation is unknown at this time.
... At Step [c], the upstream liquid fuel surface temperature increased to above the 23 .C .ash p... more ... At Step [c], the upstream liquid fuel surface temperature increased to above the 23 .C .ash point and ... The two IR images, the surface temperature of n-butanol ahead of the .ame in microgravity and ... 3. Williams, FA, Combustion Theory, Benjamin/Cum mings, Menlo Park, CA 1985. ...
A combination of chemotherapy and radiotherapy (chemoradiation therapy; CRT) has recently been de... more A combination of chemotherapy and radiotherapy (chemoradiation therapy; CRT) has recently been developed to improve the survival of esophageal cancer patients. However, the optimal choice of chemotherapeutic agents and their doses, as well as chemotherapy and radiotherapy regimens, remain unclear. Based on recent advances in knowledge on the radiosensitizing and biochemical modulation effects of chemotherapeutic agents, we have recently developed concurrent CRT which consisted of continuous 5-fluorouracil (5FU) administration (600 mg/m2/day, days 1-5) combined with a low dose of daily cisplatin administration (10 mg/m2/day, days 1-5, and 5 or 10 mg/m2/day, days 8-12 and 15-19) before each fraction of radiation (2 Gy each). To evaluate the efficacy and safety of our concurrent CRT, 10 esophageal cancer patients received one or one and a half courses of the CRT. All patients tolerated and completed a full course of the CRT. The effectiveness of the CRT on the primary tumor included pathologically or endoscopically complete responses in three patients (30%), partial response in five (50%), no response in two (20%) and tumoral downstaging (T-classification) in five (50%). Grade 2 and Grade 3 toxicity, seen in six patients, did not affect surgical operation. No patients showed CRT-related deaths. Eight patients (80%) underwent resection with no operative mortality. Of these, two patients (25%) showed pathologically or endoscopically complete responses, and four (50%) showed partial response. Three patients died of cancer after resection. The two inoperable patients showed a pathologically complete response and partial response, respectively. They were relieved of their cancer-related complaints and were living without hospitalization at the time of this analysis. These results suggest that the concurrent CRT based on the theoretical backgrounds is effective and has acceptable toxicities with maintaining its efficacy for the treatment of esophageal cancer patients.
An infrared thermograph technique with an 8-12-microm spectral range was used to measure transien... more An infrared thermograph technique with an 8-12-microm spectral range was used to measure transient two-dimensional profiles of liquid (1-propanol) surface temperatures. An IR camera was placed over the liquid, allowing us to observe the fuel surface through propanol vapor. To use this technique, one must know the emissivity of the liquid surface and the IR absorption of both the liquid propanol and the propanol vapor. The emissivity of the liquid propanol was determined with a fine thermocouple temperature measurement, IR absorption with the propanol vapor was calibrated with a blackbody source, and IR absorption with a liquid propanol was theoretically estimated. The accuracy of our infrared thermograph technique proved to be better than 97% in detecting the liquid-surface temperature with a temperature sensitivity of 0.1 degrees C and a time response of 30 ms.
We propose a nonintrusive experimental technique, the transient fuel-concentration measurement te... more We propose a nonintrusive experimental technique, the transient fuel-concentration measurement technique (TFMT), that is capable of being used to measure two-dimensional profiles of transient fuel concentrations over an open liquid fuel surface. The TFMT is based on single-wavelength holographic interferometry; its response time is less than 1 mus and spatial resolution is 0.1 mol. %/0.1 mm. It was applied to measure both methanol vapor and n-propanol vapor concentrations. To assess the accuracy of the technique, our results were compared with steady-state methanol and n-propanol fuel-vapor concentrations measured by other researchers with a microsampling technique combined with gas chromatography. We found the TFMT to be accurate for on-line monitoring of two-dimensional profiles of fuel-vapor concentrations.
Cigarette smoke is harmful to human health at both cellular and genetic levels. Recently, a uniqu... more Cigarette smoke is harmful to human health at both cellular and genetic levels. Recently, a unique bioassay for smoke cytotoxicity using air pollution-sensitive plant cells (tobacco) has been proposed. Model plant cells (tobacco Bel-W3 cells) and human cells (alveolar epithelial A549 cells) suspended in fresh culture media were exposed to cigarette smoke sampled after lighting the tip of cigarettes (with vs. without menthol capsules) which were attached to a glass pipe connected to the cell-containing plastic tubes. Control cultures were also assessed. After exposing tobacco plant cells to cigarette smoke, cell death occurred in a dose-dependent manner. Cell death was significantly enhanced by mentholated smoke, while menthol alone was shown to be inert suggesting that menthol synergistically contributes to the enhancement of cell death, initiated by smoke-associated compounds. The enhanced toxicity of mentholated smoke was confirmed in human alveolar epithelial A549 cells. Cigarette smoke cytotoxicity leading to cell death assessed in plant and human model cells was enhanced by menthol. Further research into these findings is encouraged.
ABSTRACT The pulsating flame spread over liquid fuels consists of main-pulsation with 0.5 to 2 Hz... more ABSTRACT The pulsating flame spread over liquid fuels consists of main-pulsation with 0.5 to 2 Hz frequency and sub-pulsation with 5 to 10 Hz frequency. The former originates in existence of a cold temperature valley at the liquid surface ahead of the spreading flame. The cold temperature valley is formed by the surface wave in connection with a sub-surface layer circulation. In this study, the instability analysis for the liquid surface ahead of a flame leading edge was performed to clarify the onset of surface wave. Moreover the effect of gravity on surface wave generation was examined. The theoretical result shows that the onset of surface wave is firstly controlled by Marangoni force and secondary by buoyancy force. The critical condition for onset of surface wave was expressed to the non-dimensional form. Three dimensionless parameters, the Marangoni number, the Weber number and the Froude number include the ratio, ħ/L, of the characteristic length, L, and the depth, ħ, of sub-surface layer circulation (shown in Fig. 1). F1 The circulation scale for seven different thickness of liquid fuel from 2 to 20 mm was measured using a schlieren photograph and thermography. The ratio, ħ/L, decreases with decreasing fuel layer thickness less than 5 mm and consists to μg condition at the fuel layer thickness of 3 mm.
International Journal of Chemical Engineering, 2008
... 1999. T. Konishi, G. Tashtoush, A. Ito, A. Narumi, and K. Saito, The effect of a cold temper... more ... 1999. T. Konishi, G. Tashtoush, A. Ito, A. Narumi, and K. Saito, The effect of a cold temperature valley on pulsating flame spread over propanol, Proceedings of the Combustion Institute, vol. 28, no. 2, pp. 28192826, 2000. ...
Experiments using a particle-track laser sheet technique (PTLS) combined with a high speed video ... more Experiments using a particle-track laser sheet technique (PTLS) combined with a high speed video camera were conducted to reveal the flame structure and flow vector diagram in medium-size pool fires. To improve our understanding of the scale effects on buoyancy controlled flame structure, we employed four different size liquid pool fires whose pan diameters are 10, 20, 30 and 50 cm. These results were compared with numerical analysis previously presented by other researchers. The flow visualization results at the vertical plane along a center axis are in good agreement with numerical results. However, air entrainment through the flame is estimated to be at most 30% larger than that of axis-symmetric smooth flame because of an increase in the reaction surface area and the existing rotational velocity component around the wrinkled flame. For a medium-size pool fire below 20 cm-diameter pan, the flame height and the puffing frequency are close to an assembled small-size pool fire in which 3 cm-diameter pans are lined around a circle. The flame structure below 20 cm-diameter seems to be composed of several flame cells. While the flame structure above 30 cm-diameter is quite different from the aggregate of small-size pool fires. For a 50 cm-diameter pool fire a wrinkled flame having a high frequent disturbance of 12–14 Hz occurs near the base flame zone and grows along the flame surface. A pool fire beyond 50 cm diameter pan becomes a large-scale pool fire having a turbulent flow structure.
Stability and scaling analyses were applied to experimental data obtained by this group and other... more Stability and scaling analyses were applied to experimental data obtained by this group and other researchers on pulsating flame spread over liquids. Data to be analyzed include recent findings of cyclic appearance of a cold temperature valley at the liquid surface-created surface-wave ahead of the spreading flame, and main-pulsation of 0.5–2Hz and sub-pulsation of 5–10Hz. Our stability analysis is performed
ABSTRACT The detailed temperature structure that was created during a pulsating flame spread over... more ABSTRACT The detailed temperature structure that was created during a pulsating flame spread over n-butanol was measured using holographic interferometer, shadowgraph, and IR thermograph techniques. This study found that there was a small surface wave over the previously observed cold-temperature valley located about 10 mm ahead of the spreading flame's leading edge. The newly observed surface wave was located between the spreading flame edge and the cold-temperature valley. The crest of the wave was higher than the quenching distance of the spreading flame. Due to the formation of a small gas-phase circulation cell that was observed to exist between the wave crest and the flame leading edge by laser sheet particle tracking and smoke-tracing techniques, the flammable gas mixture cannot spread beyond the wave crest; therefore, the flame's leading edge was not able to propagate beyond the wave crest. The crawling spread process was believed to be a spread process with constant speed, but this study found that it consists of a small-scale pulsation (subpulsation) with 6–12 Hz frequency. Subpulsation seems likely to have a correlation with the cyclic apperance and disappearance of a small gas-phase circulation cell that travels between the flame edge and the wave crest. When the crawling process provided sufficient heat to the liquid, the cold-temperature valley disappeared. Then the warm liquid helped to form a flammable gas layer over its surface, enabling the flame to propagate through the layer. This is called the “main” pulsating spread, a typically observed pulsating flame-spread phenomenon. This study revealed that a millimeter-order surface wave is responsible for the subpulsation that is responsible for the main pulsating spread. However, the mechanism of surface wave formation is unknown at this time.
... At Step [c], the upstream liquid fuel surface temperature increased to above the 23 .C .ash p... more ... At Step [c], the upstream liquid fuel surface temperature increased to above the 23 .C .ash point and ... The two IR images, the surface temperature of n-butanol ahead of the .ame in microgravity and ... 3. Williams, FA, Combustion Theory, Benjamin/Cum mings, Menlo Park, CA 1985. ...
A combination of chemotherapy and radiotherapy (chemoradiation therapy; CRT) has recently been de... more A combination of chemotherapy and radiotherapy (chemoradiation therapy; CRT) has recently been developed to improve the survival of esophageal cancer patients. However, the optimal choice of chemotherapeutic agents and their doses, as well as chemotherapy and radiotherapy regimens, remain unclear. Based on recent advances in knowledge on the radiosensitizing and biochemical modulation effects of chemotherapeutic agents, we have recently developed concurrent CRT which consisted of continuous 5-fluorouracil (5FU) administration (600 mg/m2/day, days 1-5) combined with a low dose of daily cisplatin administration (10 mg/m2/day, days 1-5, and 5 or 10 mg/m2/day, days 8-12 and 15-19) before each fraction of radiation (2 Gy each). To evaluate the efficacy and safety of our concurrent CRT, 10 esophageal cancer patients received one or one and a half courses of the CRT. All patients tolerated and completed a full course of the CRT. The effectiveness of the CRT on the primary tumor included pathologically or endoscopically complete responses in three patients (30%), partial response in five (50%), no response in two (20%) and tumoral downstaging (T-classification) in five (50%). Grade 2 and Grade 3 toxicity, seen in six patients, did not affect surgical operation. No patients showed CRT-related deaths. Eight patients (80%) underwent resection with no operative mortality. Of these, two patients (25%) showed pathologically or endoscopically complete responses, and four (50%) showed partial response. Three patients died of cancer after resection. The two inoperable patients showed a pathologically complete response and partial response, respectively. They were relieved of their cancer-related complaints and were living without hospitalization at the time of this analysis. These results suggest that the concurrent CRT based on the theoretical backgrounds is effective and has acceptable toxicities with maintaining its efficacy for the treatment of esophageal cancer patients.
An infrared thermograph technique with an 8-12-microm spectral range was used to measure transien... more An infrared thermograph technique with an 8-12-microm spectral range was used to measure transient two-dimensional profiles of liquid (1-propanol) surface temperatures. An IR camera was placed over the liquid, allowing us to observe the fuel surface through propanol vapor. To use this technique, one must know the emissivity of the liquid surface and the IR absorption of both the liquid propanol and the propanol vapor. The emissivity of the liquid propanol was determined with a fine thermocouple temperature measurement, IR absorption with the propanol vapor was calibrated with a blackbody source, and IR absorption with a liquid propanol was theoretically estimated. The accuracy of our infrared thermograph technique proved to be better than 97% in detecting the liquid-surface temperature with a temperature sensitivity of 0.1 degrees C and a time response of 30 ms.
We propose a nonintrusive experimental technique, the transient fuel-concentration measurement te... more We propose a nonintrusive experimental technique, the transient fuel-concentration measurement technique (TFMT), that is capable of being used to measure two-dimensional profiles of transient fuel concentrations over an open liquid fuel surface. The TFMT is based on single-wavelength holographic interferometry; its response time is less than 1 mus and spatial resolution is 0.1 mol. %/0.1 mm. It was applied to measure both methanol vapor and n-propanol vapor concentrations. To assess the accuracy of the technique, our results were compared with steady-state methanol and n-propanol fuel-vapor concentrations measured by other researchers with a microsampling technique combined with gas chromatography. We found the TFMT to be accurate for on-line monitoring of two-dimensional profiles of fuel-vapor concentrations.
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Papers by T. Konishi
Model plant cells (tobacco Bel-W3 cells) and human cells (alveolar epithelial A549 cells) suspended in fresh culture media were exposed to cigarette smoke sampled after lighting the tip of cigarettes (with vs. without menthol capsules) which were attached to a glass pipe connected to the cell-containing plastic tubes. Control cultures were also assessed.
After exposing tobacco plant cells to cigarette smoke, cell death occurred in a dose-dependent manner. Cell death was significantly enhanced by mentholated smoke, while menthol alone was shown to be inert suggesting that menthol synergistically contributes to the enhancement of cell death, initiated by smoke-associated compounds. The enhanced toxicity of mentholated smoke was confirmed in human alveolar epithelial A549 cells.
Cigarette smoke cytotoxicity leading to cell death assessed in plant and human model cells was enhanced by menthol. Further research into these findings is encouraged.
Model plant cells (tobacco Bel-W3 cells) and human cells (alveolar epithelial A549 cells) suspended in fresh culture media were exposed to cigarette smoke sampled after lighting the tip of cigarettes (with vs. without menthol capsules) which were attached to a glass pipe connected to the cell-containing plastic tubes. Control cultures were also assessed.
After exposing tobacco plant cells to cigarette smoke, cell death occurred in a dose-dependent manner. Cell death was significantly enhanced by mentholated smoke, while menthol alone was shown to be inert suggesting that menthol synergistically contributes to the enhancement of cell death, initiated by smoke-associated compounds. The enhanced toxicity of mentholated smoke was confirmed in human alveolar epithelial A549 cells.
Cigarette smoke cytotoxicity leading to cell death assessed in plant and human model cells was enhanced by menthol. Further research into these findings is encouraged.