Taking the combustor composite structure of a high-strength diesel engine as the main research object,dedicated tests have been conducted to verify the accuracy of three distinct cylinder gasket pressure simulation mo...Taking the combustor composite structure of a high-strength diesel engine as the main research object,dedicated tests have been conducted to verify the accuracy of three distinct cylinder gasket pressure simulation models.Using the measured cylinder gasket compression rebound curve,a gasket unit has been designed and manufactured.For this unit,the influence of the bolt pretension,cylinder body and cylinder head material on gasket sealing pressure has been investigated systematically in conditions of thermo-mechanical coupling.The results show that the bolt pretension force is one of the most important factors affecting the cylinder gasket sealing pressure.The change of the body material has little effect on this pressure.The cylinder gasket seal pressure decreases progressively with the reduction of the elastic module of the cylinder head material.展开更多
Teletherapy units containing 60Co source are used in Egypt and worldwide for treatment of cancer diseases. One of the widely used in Egypt is Alcyon CGR MeV. Different radiotherapy facilities need to unload this 60Co ...Teletherapy units containing 60Co source are used in Egypt and worldwide for treatment of cancer diseases. One of the widely used in Egypt is Alcyon CGR MeV. Different radiotherapy facilities need to unload this 60Co unit after being disused. The head containing the source was removed and put into approved package for transportation, after the source kept in safe position. This study describes the planning and removing process of the disused sources and, transports it into its head. The personal doses measured during the process. This work pre-estimates the doses received to workers during the removing process. The workers received doses of approximately 55 μSv during the whole process. This study shows that the original lead head can be used as the source container of this 60Co unit but not as a long term storage option. The 60Co machine was smoothly dismantled and transported by trained workers and driver, using planned and controlled radiation protection, followed by ALARA (as low as reasonably achievable) rule.展开更多
基金the Medium and Heavy Duty High Power-Density Clean Energy Power of National 863 Project。
文摘Taking the combustor composite structure of a high-strength diesel engine as the main research object,dedicated tests have been conducted to verify the accuracy of three distinct cylinder gasket pressure simulation models.Using the measured cylinder gasket compression rebound curve,a gasket unit has been designed and manufactured.For this unit,the influence of the bolt pretension,cylinder body and cylinder head material on gasket sealing pressure has been investigated systematically in conditions of thermo-mechanical coupling.The results show that the bolt pretension force is one of the most important factors affecting the cylinder gasket sealing pressure.The change of the body material has little effect on this pressure.The cylinder gasket seal pressure decreases progressively with the reduction of the elastic module of the cylinder head material.
文摘Teletherapy units containing 60Co source are used in Egypt and worldwide for treatment of cancer diseases. One of the widely used in Egypt is Alcyon CGR MeV. Different radiotherapy facilities need to unload this 60Co unit after being disused. The head containing the source was removed and put into approved package for transportation, after the source kept in safe position. This study describes the planning and removing process of the disused sources and, transports it into its head. The personal doses measured during the process. This work pre-estimates the doses received to workers during the removing process. The workers received doses of approximately 55 μSv during the whole process. This study shows that the original lead head can be used as the source container of this 60Co unit but not as a long term storage option. The 60Co machine was smoothly dismantled and transported by trained workers and driver, using planned and controlled radiation protection, followed by ALARA (as low as reasonably achievable) rule.
