African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruit...African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruits against Trypanosoma evansi for trypanocidal activity. Twenty grams of powdered Terminalia chebula dried fruits was cold extracted with methanol. Obtained MPE （methanolic plant extract） was in vitro tested against Trypanosoma brucei （1 × 10^6 trypanosomes/mL of the medium in each ELISA plate wells） at concentrations （250～1,000 μg/mL） on Vero cells grown in DMEM （Debecco＇s Modified Eagle Medium） in appropriate conditions for trypanocidal activity. In-vitro cytotoxicity test of MPE of Terminalia chebula was conducted on Vero cells grown in DMEM. In-vivo assay for trypanocidal activity, each mouse was inoculated with 1 × 10^4/mL of trypanosomes and treated （48 h post inoculation） with MPE of Terminalia chebula at concentrations （12.5, 25, 50, 100 and 200 mg/kg body weight） were administered at dose rate of 100 BL per mouse via intraperitoneal route to different groups of mice, 6 mice per concentration. In-vitro cytotoxicity test was done on Veto cells at concentrations （1.58～100 μg/mL） of MPE of Terminalia chebula. Results of in-vitro trypanocidal activity varied from immobilization, reduction and to the killing of the trypanosomes. At 250 μg/mL ofMPE ofTerminalia chebula dried fruits, there was significant trypanocidal activity at 4 h of incubation and trypanosomes were not detected in corresponding ELISA plate wells at 5 h of incubation, which was statistically equivalent to reference drug, diminazine aceturate （50 μL/mL） at 4 h of incubation. Results of in-vivo trypanocidal activity revealed that at concentrations （l 2.5～25 mg/kg body weight） of MPE of Terrninalia chebula, mice in these groups survived for 6 days. While at 50 and 100 to 200 mg/kg body weight, mice in these groups survived up to 7 and 8 days, respectively. In-vitro cytotoxicity test showed that all concentrations of MPE of Terminalia chenula and diminazine aceturate were cytotoxic to cells except at 1.56 μL/mL and 6.25 μL/mL. In conclusion, MPE of Terminalia chebula dried fruits possessed trypanocidal compounds. Further study （bioassay-guided purification） is required to know the full potential of Terrninalia chebula as future trypanocide candidate.展开更多
Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow...Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow structures inside the VTs. An experimental setup was designed, and tests were performed on different convergent VT configurations at injection pressures ranging from 0.45 to 0.65 MPa. The angles of the throttle valve were arranged between 30° to 90°, and the numbers of injection nozzles ranged between 2 and 6. Laboratory results indicated that the maximum hot and cold temperature drops ranged from 23.24 to 35 K and from 22.87 to 32.88 K, respectively, at four injection nozzles. Results also showed that temperature drop is a function of hot throttle valve angle with the maximum hot and cold temperature drops depending on the angle applied. We used graphs to demonstrate the changes in the cold and hot temperature drops with respect to hot throttle angle values. These values were interpreted and evaluated to determine the optimum angle, which was 60°. The CFD outputs agreed very well with the laboratory results. The proposed CFD results can help future researchers gain good insights into the complicated separation process taking place inside the VTs.展开更多
Soil liquefaction, and the permanent deformations that frequently result from it, have caused significant damage in past earthquakes. The procedures used in contemporary geotechnical earthquake engineering practice ar...Soil liquefaction, and the permanent deformations that frequently result from it, have caused significant damage in past earthquakes. The procedures used in contemporary geotechnical earthquake engineering practice are generally based on simplified procedures for the evaluation of the liquefaction potential. The work describes a framework for performance-based earthquake engineering and its use in the development of a performance-based procedure for liquefaction hazard evaluation. The performance-based procedure will be used to show how consistent application of conventional procedures for evaluation of liquefaction potential can influence performance prediction. Implications for liquefaction-resistant design will also be discussed. The purpose is to summarize current procedures for practical prediction of liquefaction behavior, to describe recent advances in the understanding of liquefaction behavior, and to describe the incorporation of this improved understanding into new solutions for detailed modeling of soil liquefaction, Simplified procedures for evaluation of liquefaction hazards will be reviewed relatively briefly, with more details devoted to emerging knowledge about the mechanics of liquefiable soil behavior, and methods for incorporating those mechanics into improved models for performance prediction. In particular it focuses about the influence on the evaluation of Cyclic Resistance Ratio （CRR） by different in-situ tests （Cone Penetration Test （CPT）. Standard Penetration Test （SPT） and Seismic Dilatometer Marchetti Test （SDMT）） and by different shear waves velocity measurements （Down Hole D-H. Cross Hole C-H, Seismic Dilatometer Marchetti Test SDMT）.展开更多
Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated tha...Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated that China red pine (Pinus massoniana) needles are easy to burn under the condition of the incident radiant flux at 75 kW/m^2 and ignition source, the peak value of heat release rate of pine needles appears earlier (22 s) and higher (146 kW/m^2). S. superba leaves burnt slowly and had a lower total heat release. The mass loss curves present that the peak value of pine needle is higher than that of S.superba leaves, which is 0.14 g/s versus S.superba 0.08 g/s. A fire experiment has been done in a suburb of Guangzhou City. It was measured that the fuel loads and their distribution of the stand of pine and fuelbreak before and after the fire experiment. There was almost no grass and litter on the ground of the fuelbreak due to clearing litter every year at the beginning of fire season. In the pine forest, there were shrubs, grasses and litter under the story.During the burning experiment, most of the pine forest has swept by surface fire at a spread speed of 2.2 m/min and fire intensity of 168-2961 kW/m. But in some area along the outside fire line, there occurred crown fire due to the high fuel load on the ground. The flame got 8.0-8.5 m high and fire intensity 24 881～28 379 kW/m. Part crown of several trees of the fuelbreak burnt because the crown fire spread. But the fire had not across the fuelbreak and no spotting fire happened. The fire experiment results indicated that the fuelbreak has effects on mitigating fire intensity and depress fire spread in some degree. The shaded fuelbreak has the ability of fire resistance and its dense crown can block spotting fire resources.展开更多
文摘African trypanosomosis had caused lots of havocs to both humans and animals over a century with successes and failure in curtailing it. This study was aimed at screening medicinal plant, Terminalia chebula dried fruits against Trypanosoma evansi for trypanocidal activity. Twenty grams of powdered Terminalia chebula dried fruits was cold extracted with methanol. Obtained MPE （methanolic plant extract） was in vitro tested against Trypanosoma brucei （1 × 10^6 trypanosomes/mL of the medium in each ELISA plate wells） at concentrations （250～1,000 μg/mL） on Vero cells grown in DMEM （Debecco＇s Modified Eagle Medium） in appropriate conditions for trypanocidal activity. In-vitro cytotoxicity test of MPE of Terminalia chebula was conducted on Vero cells grown in DMEM. In-vivo assay for trypanocidal activity, each mouse was inoculated with 1 × 10^4/mL of trypanosomes and treated （48 h post inoculation） with MPE of Terminalia chebula at concentrations （12.5, 25, 50, 100 and 200 mg/kg body weight） were administered at dose rate of 100 BL per mouse via intraperitoneal route to different groups of mice, 6 mice per concentration. In-vitro cytotoxicity test was done on Veto cells at concentrations （1.58～100 μg/mL） of MPE of Terminalia chebula. Results of in-vitro trypanocidal activity varied from immobilization, reduction and to the killing of the trypanosomes. At 250 μg/mL ofMPE ofTerminalia chebula dried fruits, there was significant trypanocidal activity at 4 h of incubation and trypanosomes were not detected in corresponding ELISA plate wells at 5 h of incubation, which was statistically equivalent to reference drug, diminazine aceturate （50 μL/mL） at 4 h of incubation. Results of in-vivo trypanocidal activity revealed that at concentrations （l 2.5～25 mg/kg body weight） of MPE of Terrninalia chebula, mice in these groups survived for 6 days. While at 50 and 100 to 200 mg/kg body weight, mice in these groups survived up to 7 and 8 days, respectively. In-vitro cytotoxicity test showed that all concentrations of MPE of Terminalia chenula and diminazine aceturate were cytotoxic to cells except at 1.56 μL/mL and 6.25 μL/mL. In conclusion, MPE of Terminalia chebula dried fruits possessed trypanocidal compounds. Further study （bioassay-guided purification） is required to know the full potential of Terrninalia chebula as future trypanocide candidate.
文摘Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow structures inside the VTs. An experimental setup was designed, and tests were performed on different convergent VT configurations at injection pressures ranging from 0.45 to 0.65 MPa. The angles of the throttle valve were arranged between 30° to 90°, and the numbers of injection nozzles ranged between 2 and 6. Laboratory results indicated that the maximum hot and cold temperature drops ranged from 23.24 to 35 K and from 22.87 to 32.88 K, respectively, at four injection nozzles. Results also showed that temperature drop is a function of hot throttle valve angle with the maximum hot and cold temperature drops depending on the angle applied. We used graphs to demonstrate the changes in the cold and hot temperature drops with respect to hot throttle angle values. These values were interpreted and evaluated to determine the optimum angle, which was 60°. The CFD outputs agreed very well with the laboratory results. The proposed CFD results can help future researchers gain good insights into the complicated separation process taking place inside the VTs.
文摘Soil liquefaction, and the permanent deformations that frequently result from it, have caused significant damage in past earthquakes. The procedures used in contemporary geotechnical earthquake engineering practice are generally based on simplified procedures for the evaluation of the liquefaction potential. The work describes a framework for performance-based earthquake engineering and its use in the development of a performance-based procedure for liquefaction hazard evaluation. The performance-based procedure will be used to show how consistent application of conventional procedures for evaluation of liquefaction potential can influence performance prediction. Implications for liquefaction-resistant design will also be discussed. The purpose is to summarize current procedures for practical prediction of liquefaction behavior, to describe recent advances in the understanding of liquefaction behavior, and to describe the incorporation of this improved understanding into new solutions for detailed modeling of soil liquefaction, Simplified procedures for evaluation of liquefaction hazards will be reviewed relatively briefly, with more details devoted to emerging knowledge about the mechanics of liquefiable soil behavior, and methods for incorporating those mechanics into improved models for performance prediction. In particular it focuses about the influence on the evaluation of Cyclic Resistance Ratio （CRR） by different in-situ tests （Cone Penetration Test （CPT）. Standard Penetration Test （SPT） and Seismic Dilatometer Marchetti Test （SDMT）） and by different shear waves velocity measurements （Down Hole D-H. Cross Hole C-H, Seismic Dilatometer Marchetti Test SDMT）.
文摘Schima superba is widely used for shaded fuelbreaks in southern China. Experiments were done in the laboratory and wild for testing the effects of the shaded fuelbreaks. The cone calorimeter test results indicated that China red pine (Pinus massoniana) needles are easy to burn under the condition of the incident radiant flux at 75 kW/m^2 and ignition source, the peak value of heat release rate of pine needles appears earlier (22 s) and higher (146 kW/m^2). S. superba leaves burnt slowly and had a lower total heat release. The mass loss curves present that the peak value of pine needle is higher than that of S.superba leaves, which is 0.14 g/s versus S.superba 0.08 g/s. A fire experiment has been done in a suburb of Guangzhou City. It was measured that the fuel loads and their distribution of the stand of pine and fuelbreak before and after the fire experiment. There was almost no grass and litter on the ground of the fuelbreak due to clearing litter every year at the beginning of fire season. In the pine forest, there were shrubs, grasses and litter under the story.During the burning experiment, most of the pine forest has swept by surface fire at a spread speed of 2.2 m/min and fire intensity of 168-2961 kW/m. But in some area along the outside fire line, there occurred crown fire due to the high fuel load on the ground. The flame got 8.0-8.5 m high and fire intensity 24 881～28 379 kW/m. Part crown of several trees of the fuelbreak burnt because the crown fire spread. But the fire had not across the fuelbreak and no spotting fire happened. The fire experiment results indicated that the fuelbreak has effects on mitigating fire intensity and depress fire spread in some degree. The shaded fuelbreak has the ability of fire resistance and its dense crown can block spotting fire resources.
