This study proposes a two-color laser-induced fluorescence (LIF) technique for measuring the temperature distribution of an airflow by spraying a mist of a fluorescent dye. The mist is generated by using propylene gly...This study proposes a two-color laser-induced fluorescence (LIF) technique for measuring the temperature distribution of an airflow by spraying a mist of a fluorescent dye. The mist is generated by using propylene glycol, the vapor pressure of which is much lower than that of water, as the solvent of the fluorescent dyes. A supersonic moisture chamber is used as the atomizer for seeding the tracer particles to be visualized. The proposed technique is applied to the measurement of the temperature distribution in a thermal vertical buoyant plume. The proposed two-color LIF thermometry is found to be very effective for the study of such a thermal structure, and it is well suited for measuring the temperature field of an airflow.展开更多
Sadatomi and Kawahara developed a special twin-fluid atomizer called a multi-fluid mixer, which can spray mists by supplying air alone because water is automatically sucked by a vacuum pressure arisen inside the mixer...Sadatomi and Kawahara developed a special twin-fluid atomizer called a multi-fluid mixer, which can spray mists by supplying air alone because water is automatically sucked by a vacuum pressure arisen inside the mixer. In the present paper, firstly, some applications of the mists sprayed by the atomizer are described. Secondly, the performance of the twin-fluid atomizer with best performance was compared with those of the commercial twin-fluid MMA100 type together with the single-fluid swirl type. In the CO2 adsorption tests, mists were sprayed five minutes by the respective types in turn in a test room, and time variations of CO2 concentration in air after the introduction of CO2 in the room were measured at the bottom of the room to compare the CO2 adsorption rates by the mists for the respective cases. In addition, diameters of droplets for the respective types were measured with a microscope. As a result, superiority of our twin-fluid atomizer was confirmed, because 40% droplets were 20 to 40 μm in diameter, and the CO2 adsorption rate by the mists with our twin-fluid atomizer was 25% higher than that with the commercial ones.展开更多
Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generat...Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.展开更多
Nujiang farmers use the innovative dryland rice cultivation technology developed by a Chinese expert team to grow yields and income.As April ushers in spring,mist clings to the deep valleys of the Nujiang Grand Canyon...Nujiang farmers use the innovative dryland rice cultivation technology developed by a Chinese expert team to grow yields and income.As April ushers in spring,mist clings to the deep valleys of the Nujiang Grand Canyon in Southwest China’s Yunnan Province.High on a mountainside in Ziji Village,Daxingdi Town,Lushui City,Nujiang Lisu Autonomous Prefecture,at an altitude exceeding 1,300 metres,62-year-old Lisu villager Cha Wenxing is planting rice.These demonstration plots,cultivating high-quality upland rice,seem to float amongst the clouds.展开更多
As 1.5 million wildebeest pierce the dawn mist of the East African Rift Valley and the roar of lions merges with the cry of zebras beneath sprawling acacia trees,this land unveils life at its rawest-majestic and achin...As 1.5 million wildebeest pierce the dawn mist of the East African Rift Valley and the roar of lions merges with the cry of zebras beneath sprawling acacia trees,this land unveils life at its rawest-majestic and achingly fragile.展开更多
“It's coming!”Liu Fuhai shouted,lying prone on a rock,one of his eyes pressed against his camera.Beads of sweat could be seen on his forehead.Roaring water in the Yellow River plunged from the cliff,making gigan...“It's coming!”Liu Fuhai shouted,lying prone on a rock,one of his eyes pressed against his camera.Beads of sweat could be seen on his forehead.Roaring water in the Yellow River plunged from the cliff,making gigantic splashes(落水声)which eventually turned into thick mists.Liu,holding his breath,clicked the shutter quickly to capture the grandeur of the Hukou Waterfall,the largest waterfall on the Yellow River.展开更多
To investigate the explosion load characteristics and structural response law in a water mist environment in a cabin,explosion experiments are carried out.The weakening rates of the initial peak overpressure,quasistat...To investigate the explosion load characteristics and structural response law in a water mist environment in a cabin,explosion experiments are carried out.The weakening rates of the initial peak overpressure,quasistatic pressure and structural residual deflection increase with increasing working pressure of the water mist nozzle.Specifically,the weakening rate of the initial peak overpressure ranges from 7.8%to 31.0%,the quasistatic pressure weakening rate ranges from 29.2%to 41.0%,and the weakening rate of the center of the plate residual deflection ranges from 10.8%to 34.4%under the various working pressures of the nozzles.To further explore the effect of water mist explosion suppression,a method for three-dimensional numerical simulations of water mist weakening the explosion shock wave is established to explore the explosion load characteristics of the compartment and the bulkhead response law.On the basis of the dimension analysis method,empirical formulas are derived to predict the residual deflection thickness in the center of the bulkheads.These findings provide the fundamental basis for the appli-cation of water mist in anti-explosive protection.展开更多
The role of cold nitrogen gas and oil mist on tool wear and surface roughness is investigated in turning the K424 nickel-base super alloy with Sialon and SiC whisker-reinforced alumina ceramic tools. A new cooling sys...The role of cold nitrogen gas and oil mist on tool wear and surface roughness is investigated in turning the K424 nickel-base super alloy with Sialon and SiC whisker-reinforced alumina ceramic tools. A new cooling system is developed and used to lower the temperature of the compressed nitrogen gas. Experiments are performed in three different cooling/lubrication modes, i.e. the dry cutting, the cold nitrogen gas （CNG）, and the cold nitrogen gas and oil mist （CNGOM）. Experimental results show that the depth-of-cut notching severely limits the tool life in all the cooling/lubrication modes. Compared with the dry cutting, the use of CNG and CNGOMcan yield higher wear rate of depth-of-cut notching and worse surface finish.展开更多
Green manufacturing （GM） and high efficiency machining technology are inevitable trends in the field of advanced manufacturing of the 21st century. To ensure green and high-efficiency machining, a new high efficienc...Green manufacturing （GM） and high efficiency machining technology are inevitable trends in the field of advanced manufacturing of the 21st century. To ensure green and high-efficiency machining, a new high efficiency cooling technology-cryogenic pneumatic mist jet impinging cooling （CPMJI） technology is presented. For obtaining the best cooling effect, a little quantity of coolant is carried by high speed cryogenic air （-20 C ） and reaches the machining zone in the form of mist jet to enhance heat transfer. Experimental results indicate that under the conditions of 40 m/s in the jet impinging speed and 10 mm in the jet impinging distance, the critical heat flux（CHF） nearly reaches 6× 10^7 W/m^2, more than six times of the CHF of the grinding burn with a value of （8～10）×10^6 W/m^2.展开更多
To understand better the impact on mist net capture rates of the activity height of birds, light intensity, bird richness and abundance, we compared data from mist nets and point counts at the Jianfengling Forest Area...To understand better the impact on mist net capture rates of the activity height of birds, light intensity, bird richness and abundance, we compared data from mist nets and point counts at the Jianfengling Forest Area, Hainan Island. Mist-nets were operated for a total of 7135 net-hours. A total of 587 individuals of 45 bird species were captured. The total mean capture rate was 8.6 ± 10.4 per 100 net-hours. A total of 4932 individuals of 107 bird species were recorded by visual observation alone and 7616 individuals of 120 species were recorded in a visual and aural combination. The Grey-cheeked Fulvetta (Alcippe morrisonia) was the most abundant species, accounting for 38.7% of total captures, 27.9% of visual observations and 22.2% of visual + aural observations. The capture number was correlated with the number observed. Thirty-one species were more likely to be captured than observed. Canopy species, such as members of the Corvidae and Dicruridae, were seldom captured. For all ground feeding species, the capture number was greater than that of observation. Some cryptic species, such as the Lesser Wren Babbler (Napothera epilepidota), Spotnecked Babbler (Stachyris striolata) and Cuckoo Owl (Glaucidium cuculoides) also had a higher relative capture rate than that of observations. There was a significant relationship between light intensity and the number of birds captured.展开更多
A method of reliability analysis based on a direct strength calculation employing the von Mises stress failure criterion is presented here. The short term strain distributions of ship hull structural components are id...A method of reliability analysis based on a direct strength calculation employing the von Mises stress failure criterion is presented here. The short term strain distributions of ship hull structural components are identified through the statistical analysis of the wave-induced strain history and the long term distributions by the weighted summation of the short term strain distributions. The wave-induced long term strain distribution is combined with the still water strain. The extreme strain distribution of the response strain is obtained by statistical analysis of the combined strains. The limit state function of the reliability analysis is based on the von Mises stress failure criterion, including the related uncertainties due to the quality of the material and model uncertainty. The reliability index is calculated using FORM and sensitivity analysis of each variable that has effects on the reliability is also discussed.展开更多
（上接《IS0/TC8与IM0要求的关系及其国际标准-2》[1-2]）ISO16437：2012 船舶与海上技术-救生与防火-船舶油雾探测器（Ships and marine technology-Lifesaving and fire protection--Atmospheric oil mist detectors for
The effects of a fine water mist environment in a semi-confined blast chamber on the chemical and thermodynamic processes following detonation of a 20 g PE4 explosive charge have been investigated.The effects were qua...The effects of a fine water mist environment in a semi-confined blast chamber on the chemical and thermodynamic processes following detonation of a 20 g PE4 explosive charge have been investigated.The effects were quantified by the analysis of pressure profiles recorded where several parameters including arrival time of the shock at the sensors, peak overpressures, specific impulse of the positive phase, period of the negative phase and the specific impulse of the multiple reflections were quantified.The effect of the fine water mist on the arrival time, peak pressures and the specific impulse of the positive phase agrees with previous findings in literature. In this paper, the focus is on the implications of the fine water mist on the negative phase and the impulse of multiple pressure reflections. The period of the negative phase was found to have increased by 40% and with higher negative peak pressure in the mist condition compared to the atmospheric condition. The activities of the multiple pressure reflections were found to have decreased considerably, both in number and in amplitude leading to lower impulses(by about 60%) for the water mist conditions.展开更多
文摘This study proposes a two-color laser-induced fluorescence (LIF) technique for measuring the temperature distribution of an airflow by spraying a mist of a fluorescent dye. The mist is generated by using propylene glycol, the vapor pressure of which is much lower than that of water, as the solvent of the fluorescent dyes. A supersonic moisture chamber is used as the atomizer for seeding the tracer particles to be visualized. The proposed technique is applied to the measurement of the temperature distribution in a thermal vertical buoyant plume. The proposed two-color LIF thermometry is found to be very effective for the study of such a thermal structure, and it is well suited for measuring the temperature field of an airflow.
文摘Sadatomi and Kawahara developed a special twin-fluid atomizer called a multi-fluid mixer, which can spray mists by supplying air alone because water is automatically sucked by a vacuum pressure arisen inside the mixer. In the present paper, firstly, some applications of the mists sprayed by the atomizer are described. Secondly, the performance of the twin-fluid atomizer with best performance was compared with those of the commercial twin-fluid MMA100 type together with the single-fluid swirl type. In the CO2 adsorption tests, mists were sprayed five minutes by the respective types in turn in a test room, and time variations of CO2 concentration in air after the introduction of CO2 in the room were measured at the bottom of the room to compare the CO2 adsorption rates by the mists for the respective cases. In addition, diameters of droplets for the respective types were measured with a microscope. As a result, superiority of our twin-fluid atomizer was confirmed, because 40% droplets were 20 to 40 μm in diameter, and the CO2 adsorption rate by the mists with our twin-fluid atomizer was 25% higher than that with the commercial ones.
基金financial support from the Nuclear Energy Science&Technology and Human Resource Development Project of the Japan Atomic Energy Agency/Collaborative Laboratories for Advanced Decommissioning Science(No.R04I034)The author Ruicong Xu appreciates the scholarship(financial support)from the China Scholarship Council(CSC,No.202106380073).
文摘Laser-induced aerosols,predominantly submicron in size,pose significant environmental and health risks during the decommissioning of nuclear reactors.This study experimentally investigated the removal of laser-generated aerosol particles using a water spray system integrated with an innovative system for pre-injecting electrically charged mist in our facility.To simulate aerosol generation in reactor decommissioning,a high-power laser was used to irradiate various materials(including stainless steel,carbon steel,and concrete),generating aerosol particles that were agglomerated with injected water mist and subsequently scavenged by water spray.Experimental results demonstrate enhanced aerosol removal via aerosol-mist agglomeration,with charged mist significantly improving particle capture by increasing wettability and size.The average improvements for the stainless steel,carbon steel,and concrete were 40%,44%,and 21%,respectively.The results of experiments using charged mist with different polarities(both positive and negative)and different surface coatings reveal that the dominant polarity of aerosols varies with the irradiated materials,influenced by their crystal structure and electron emission properties.Notably,surface coatings such as ZrO_(2)and CeO_(2)were found to possibly alter aerosol charging characteristics,thereby affecting aerosol removal efficiency with charged mist configurations.The innovative aerosol-mist agglomeration approach shows promise in mitigating radiation exposure,ensuring environmental safety,and reducing contaminated water during reactor dismantling.This study contributes critical knowledge for the development of advanced aerosol management strategies for nuclear reactor decommissioning.The understanding obtained in this work is also expected to be useful for various environmental and chemical engineering applications such as gas decontamination,air purification,and pollution control.
文摘Nujiang farmers use the innovative dryland rice cultivation technology developed by a Chinese expert team to grow yields and income.As April ushers in spring,mist clings to the deep valleys of the Nujiang Grand Canyon in Southwest China’s Yunnan Province.High on a mountainside in Ziji Village,Daxingdi Town,Lushui City,Nujiang Lisu Autonomous Prefecture,at an altitude exceeding 1,300 metres,62-year-old Lisu villager Cha Wenxing is planting rice.These demonstration plots,cultivating high-quality upland rice,seem to float amongst the clouds.
文摘As 1.5 million wildebeest pierce the dawn mist of the East African Rift Valley and the roar of lions merges with the cry of zebras beneath sprawling acacia trees,this land unveils life at its rawest-majestic and achingly fragile.
文摘“It's coming!”Liu Fuhai shouted,lying prone on a rock,one of his eyes pressed against his camera.Beads of sweat could be seen on his forehead.Roaring water in the Yellow River plunged from the cliff,making gigantic splashes(落水声)which eventually turned into thick mists.Liu,holding his breath,clicked the shutter quickly to capture the grandeur of the Hukou Waterfall,the largest waterfall on the Yellow River.
基金supported by the National Natural Science Foundation of China(grant numbers:52201334)sup-ported by National Key Laboratory of Ship Structural Safety(grant numbers:Naklas2024-KF015-s).
文摘To investigate the explosion load characteristics and structural response law in a water mist environment in a cabin,explosion experiments are carried out.The weakening rates of the initial peak overpressure,quasistatic pressure and structural residual deflection increase with increasing working pressure of the water mist nozzle.Specifically,the weakening rate of the initial peak overpressure ranges from 7.8%to 31.0%,the quasistatic pressure weakening rate ranges from 29.2%to 41.0%,and the weakening rate of the center of the plate residual deflection ranges from 10.8%to 34.4%under the various working pressures of the nozzles.To further explore the effect of water mist explosion suppression,a method for three-dimensional numerical simulations of water mist weakening the explosion shock wave is established to explore the explosion load characteristics of the compartment and the bulkhead response law.On the basis of the dimension analysis method,empirical formulas are derived to predict the residual deflection thickness in the center of the bulkheads.These findings provide the fundamental basis for the appli-cation of water mist in anti-explosive protection.
文摘The role of cold nitrogen gas and oil mist on tool wear and surface roughness is investigated in turning the K424 nickel-base super alloy with Sialon and SiC whisker-reinforced alumina ceramic tools. A new cooling system is developed and used to lower the temperature of the compressed nitrogen gas. Experiments are performed in three different cooling/lubrication modes, i.e. the dry cutting, the cold nitrogen gas （CNG）, and the cold nitrogen gas and oil mist （CNGOM）. Experimental results show that the depth-of-cut notching severely limits the tool life in all the cooling/lubrication modes. Compared with the dry cutting, the use of CNG and CNGOMcan yield higher wear rate of depth-of-cut notching and worse surface finish.
文摘Green manufacturing （GM） and high efficiency machining technology are inevitable trends in the field of advanced manufacturing of the 21st century. To ensure green and high-efficiency machining, a new high efficiency cooling technology-cryogenic pneumatic mist jet impinging cooling （CPMJI） technology is presented. For obtaining the best cooling effect, a little quantity of coolant is carried by high speed cryogenic air （-20 C ） and reaches the machining zone in the form of mist jet to enhance heat transfer. Experimental results indicate that under the conditions of 40 m/s in the jet impinging speed and 10 mm in the jet impinging distance, the critical heat flux（CHF） nearly reaches 6× 10^7 W/m^2, more than six times of the CHF of the grinding burn with a value of （8～10）×10^6 W/m^2.
基金funded by the Kadoorie Farm and Botanical Garden and the Hong Kong Special Administrative Region,China
文摘To understand better the impact on mist net capture rates of the activity height of birds, light intensity, bird richness and abundance, we compared data from mist nets and point counts at the Jianfengling Forest Area, Hainan Island. Mist-nets were operated for a total of 7135 net-hours. A total of 587 individuals of 45 bird species were captured. The total mean capture rate was 8.6 ± 10.4 per 100 net-hours. A total of 4932 individuals of 107 bird species were recorded by visual observation alone and 7616 individuals of 120 species were recorded in a visual and aural combination. The Grey-cheeked Fulvetta (Alcippe morrisonia) was the most abundant species, accounting for 38.7% of total captures, 27.9% of visual observations and 22.2% of visual + aural observations. The capture number was correlated with the number observed. Thirty-one species were more likely to be captured than observed. Canopy species, such as members of the Corvidae and Dicruridae, were seldom captured. For all ground feeding species, the capture number was greater than that of observation. Some cryptic species, such as the Lesser Wren Babbler (Napothera epilepidota), Spotnecked Babbler (Stachyris striolata) and Cuckoo Owl (Glaucidium cuculoides) also had a higher relative capture rate than that of observations. There was a significant relationship between light intensity and the number of birds captured.
文摘A method of reliability analysis based on a direct strength calculation employing the von Mises stress failure criterion is presented here. The short term strain distributions of ship hull structural components are identified through the statistical analysis of the wave-induced strain history and the long term distributions by the weighted summation of the short term strain distributions. The wave-induced long term strain distribution is combined with the still water strain. The extreme strain distribution of the response strain is obtained by statistical analysis of the combined strains. The limit state function of the reliability analysis is based on the von Mises stress failure criterion, including the related uncertainties due to the quality of the material and model uncertainty. The reliability index is calculated using FORM and sensitivity analysis of each variable that has effects on the reliability is also discussed.
文摘（上接《IS0/TC8与IM0要求的关系及其国际标准-2》[1-2]）ISO16437：2012 船舶与海上技术-救生与防火-船舶油雾探测器（Ships and marine technology-Lifesaving and fire protection--Atmospheric oil mist detectors for
文摘The effects of a fine water mist environment in a semi-confined blast chamber on the chemical and thermodynamic processes following detonation of a 20 g PE4 explosive charge have been investigated.The effects were quantified by the analysis of pressure profiles recorded where several parameters including arrival time of the shock at the sensors, peak overpressures, specific impulse of the positive phase, period of the negative phase and the specific impulse of the multiple reflections were quantified.The effect of the fine water mist on the arrival time, peak pressures and the specific impulse of the positive phase agrees with previous findings in literature. In this paper, the focus is on the implications of the fine water mist on the negative phase and the impulse of multiple pressure reflections. The period of the negative phase was found to have increased by 40% and with higher negative peak pressure in the mist condition compared to the atmospheric condition. The activities of the multiple pressure reflections were found to have decreased considerably, both in number and in amplitude leading to lower impulses(by about 60%) for the water mist conditions.
