The distribution of energy deposition density in radiate region and its surrounding areas from γ-rays wassimulated and analyzed for a water-ball model with Geant4 package(Geant4.7.0,2005) developed by CERN (theCenter...The distribution of energy deposition density in radiate region and its surrounding areas from γ-rays wassimulated and analyzed for a water-ball model with Geant4 package(Geant4.7.0,2005) developed by CERN (theCenter of European Research of Nucleus). The results show that the distribution depends strongly on the collimatingcondition of radiation beam. A well-collimated beam would reduce radiation effects on surrounding areas.展开更多
Objective： We studied the relationship between impact of dose distribution and energy of radioactive ray in teletherapy with contraceptive ring. Methods： The SI Virtual Water Phantom was used to monitor medium of do...Objective： We studied the relationship between impact of dose distribution and energy of radioactive ray in teletherapy with contraceptive ring. Methods： The SI Virtual Water Phantom was used to monitor medium of dose. PTW ionization chamber was used to detect the dose. AP-PA （10 cmx 10 cm） and SAD technique were adopted. Monitoring dose of different locations with different energy of radioactive ray in AP and PA respectively with and without contraceptive ring, repeated 5 times. Results： Dose of with contraceptive ring was lower than that of without contraceptive ring in AP 6 MV- X-ray （P 〈 0.05）, while in PA was no obvious difference （P 〉 0.05）. Dose of except for the center was higher than that of without contraceptive ring in AP and PA 15 MV-X-ray （P 〈 0.05）. For locations, doses of the upper, the left and right were higher than that of the center in AP 6 MV-X-ray （P 〈 0.05）, while in PA was lower （P 〉 0.05）. In AP and PA 15 MV-X-ray, doses of the upper, the left and right was higher than that of the center （P 〈 0.05）. Conclusion： Metallic contraceptive ring would effect the dose distribution of radioactive ray, but influence degree related to locations of contraceptive ring and energy of radioactive ray.展开更多
Kalbach Mann systematics is a very useful formula to discrete the double-differential cross sections of emitted particles. However, the energy balance by using this systematics is still a task to be studied. In the fo...Kalbach Mann systematics is a very useful formula to discrete the double-differential cross sections of emitted particles. However, the energy balance by using this systematics is still a task to be studied. In the form of Legendre polynomial expansion the energy balance has been proved analytically. In terms of this approach, the formula to determine the prc-equilibrium fraction r factor of Kalbach Mann systematics has been obtained for keeping energy balance strictly. This formula could be straightforwardly applied for describing the double-differential cross sections of all projectile types in the eontinuum spectrum emissions. It indicates that Legendre expansion coefficient with l= 1 is the key term in the energy balance.展开更多
Mexico is one of the largest producers of nopal （Opuntiaficus indica）. This ＂vegetable＂ is consumed on a daily basis by the Mexican population, being a source of food nutrients. Among its benefits, it is considere...Mexico is one of the largest producers of nopal （Opuntiaficus indica）. This ＂vegetable＂ is consumed on a daily basis by the Mexican population, being a source of food nutrients. Among its benefits, it is considered the content of potassium, which is essential for human life and health. In this study, it analyzes the content of potassium of the Mexican cactus （Opuntiaficus indica） grown in 5 different regions in the Mexican Basin, where 67% of the nopal is produced for human consumption. The used methodology is gamma spectrometry with Hyperpure Germanium detector （HPGe） and Multichannel Analyzer （MCA） with Maestro~ software. The results show interesting aspects on the concentration of potassium in the nopal. This concentration will primarily depend on： （a） the geological characteristics of the location where the nopal was grows; （b） that potassium concentrations may vary substantially from a region to another, with the same species of nopal as a reference and （c） that this concentration may also vary from one growing season to another.展开更多
This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a...This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.展开更多
文摘The distribution of energy deposition density in radiate region and its surrounding areas from γ-rays wassimulated and analyzed for a water-ball model with Geant4 package(Geant4.7.0,2005) developed by CERN (theCenter of European Research of Nucleus). The results show that the distribution depends strongly on the collimatingcondition of radiation beam. A well-collimated beam would reduce radiation effects on surrounding areas.
文摘Objective： We studied the relationship between impact of dose distribution and energy of radioactive ray in teletherapy with contraceptive ring. Methods： The SI Virtual Water Phantom was used to monitor medium of dose. PTW ionization chamber was used to detect the dose. AP-PA （10 cmx 10 cm） and SAD technique were adopted. Monitoring dose of different locations with different energy of radioactive ray in AP and PA respectively with and without contraceptive ring, repeated 5 times. Results： Dose of with contraceptive ring was lower than that of without contraceptive ring in AP 6 MV- X-ray （P 〈 0.05）, while in PA was no obvious difference （P 〉 0.05）. Dose of except for the center was higher than that of without contraceptive ring in AP and PA 15 MV-X-ray （P 〈 0.05）. For locations, doses of the upper, the left and right were higher than that of the center in AP 6 MV-X-ray （P 〈 0.05）, while in PA was lower （P 〉 0.05）. In AP and PA 15 MV-X-ray, doses of the upper, the left and right was higher than that of the center （P 〈 0.05）. Conclusion： Metallic contraceptive ring would effect the dose distribution of radioactive ray, but influence degree related to locations of contraceptive ring and energy of radioactive ray.
文摘Kalbach Mann systematics is a very useful formula to discrete the double-differential cross sections of emitted particles. However, the energy balance by using this systematics is still a task to be studied. In the form of Legendre polynomial expansion the energy balance has been proved analytically. In terms of this approach, the formula to determine the prc-equilibrium fraction r factor of Kalbach Mann systematics has been obtained for keeping energy balance strictly. This formula could be straightforwardly applied for describing the double-differential cross sections of all projectile types in the eontinuum spectrum emissions. It indicates that Legendre expansion coefficient with l= 1 is the key term in the energy balance.
文摘Mexico is one of the largest producers of nopal （Opuntiaficus indica）. This ＂vegetable＂ is consumed on a daily basis by the Mexican population, being a source of food nutrients. Among its benefits, it is considered the content of potassium, which is essential for human life and health. In this study, it analyzes the content of potassium of the Mexican cactus （Opuntiaficus indica） grown in 5 different regions in the Mexican Basin, where 67% of the nopal is produced for human consumption. The used methodology is gamma spectrometry with Hyperpure Germanium detector （HPGe） and Multichannel Analyzer （MCA） with Maestro~ software. The results show interesting aspects on the concentration of potassium in the nopal. This concentration will primarily depend on： （a） the geological characteristics of the location where the nopal was grows; （b） that potassium concentrations may vary substantially from a region to another, with the same species of nopal as a reference and （c） that this concentration may also vary from one growing season to another.
文摘This paper considers the combination of hydrothermal degradation （HTD） and superheated steam （SHS） drying in disposal and processing of degradable organic wastes in municipal solid wastes （MSW）. In SHS drying, a fraction of dryer thermal energy input can be recovered and used to satisfy the heat requirement in maintaining the HTD operating temperature. Both energy and exergy analysis are applied to the combined process. The analysis covers ranges of dryer inlet temperatures of 202.38-234.19~C and feed water content of 32.5-65%. Thermal energy analysis shows that the combination of HTD and SHS drying can achieve thermal energy self-sufficiency （TES） by manipulating process variables. The exergy analysis indicates the location, type, and magnitude of the exergy losses during the whole process by applying the second law of thermodynamics.
