Chongqing Zhicheng Machinery Factory One of the Top 10 Chinese Casting Enterprises in 2006 Basic informationAdd: Jiulong Town, Jiulongpo District, Chongqing 400051, China General Manager: Sun
A numerical model of foundry filling process was established based on the smoothed particle hydrodynamics（SPH）method.To mimic the constraints that the solid mold prescribes on the filling fluid,a composite treatment...A numerical model of foundry filling process was established based on the smoothed particle hydrodynamics（SPH）method.To mimic the constraints that the solid mold prescribes on the filling fluid,a composite treatment to the solid boundaries is elaborately designed.On solid boundary surfaces,boundary particles were set,which exert Lennard-Jones force on approaching fluid particles;inside the solid mold,ghost particles were arranged to complete the compact domain of near-boundary fluid particles.Water analog experiments were conducted in parallel with the model simulations.Very good agreement between experimental and simulation results demonstrates the success of model development.展开更多
本文介绍了VMware近期新推出的一个开源PaaS项目:Cloud Foundry。PaaS是Platform as a Service的缩写,意思是平台即服务。PaaS将软件部署,运行和维护整合成一种服务,以SaaS(Software as a Service软件即服务)的模式提交给开发人员。开...本文介绍了VMware近期新推出的一个开源PaaS项目:Cloud Foundry。PaaS是Platform as a Service的缩写,意思是平台即服务。PaaS将软件部署,运行和维护整合成一种服务,以SaaS(Software as a Service软件即服务)的模式提交给开发人员。开发人员可以快速地在其上进行软件开发部署,运行和扩展,而不用去搭建和维护硬件设施,安装软件中间件。将开发人员从软件部署,运行和维护软件的工作中解脱出来。本文指出了现代软件系统的新特点及遇到的挑战,介绍了PaaS的概念、Cloud Foundry的架构,分析了Cloud Foundry与业界现有几款PaaS相比的优点。最后,对PaaS未来的发展方向做了展望。展开更多
PPDB issues-four aspects of current management issues of foundry enterprises are discussed in this paper,including Production Management,Process Control,Duration Monitoring and Business Intelligence Data Analysis.Also...PPDB issues-four aspects of current management issues of foundry enterprises are discussed in this paper,including Production Management,Process Control,Duration Monitoring and Business Intelligence Data Analysis.Also a whole Enterprise Resource Planning(ERP) solution for foundry enterprises is proposed.The solution contains many models,four of which are used to solve the PPDB issues.These are called SPDB models,which separately are the Single-piece management model(based on casting lifecycle),Process management model(based on task-driven technology),Duration monitoring model(based on surplus period),and Business intelligence data analysis model(based on data mining).An ERP system for foundry enterprises,named HZERP,was researched and developed,and applied to a sand casting company of single piece and small batch production.Qualitatively and quantitatively comparing the application effect before and after implementing the HZERP system,the result demonstrated that the foundry ERP system based on the SPDB models can help metal casting enterprises achieve the single-piece management,better regulate the production processes,improve production and delivery management,shorten the production cycle,reduce costs,and speed up the capital turnover to a large extent.展开更多
Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing s...Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it （P〈0.01）. Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their cumulative silica exposure （OR-3.00, 95% CI 2.34-3.83）. Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m^3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m^3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m^3 for those with 20 years of employment, or below 0.1 mg/m^3 for those with 30 or 40 years of silica exposure. Conclusions At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthend.展开更多
with the development of computer technology, foundry CAE technology has made rapid progress. Commercialsoftware packages of casting process simulation, therefore, have become more and more practical. This paper introd...with the development of computer technology, foundry CAE technology has made rapid progress. Commercialsoftware packages of casting process simulation, therefore, have become more and more practical. This paper introducesboth the recent developments and some applications of InteCAST software, a commercial numerical simulation softwarepackage for foundry industry, with more than 120 customers all over the world. The function modules of lnteCAST8.0 andsome new techniques, such as uneven mesh technology for mold filling simulation and numerical mouse technology fordata visualization, were introduced. Several applications on special castings such as investment casting, low pressure diecasting, and high pressure die casting, were given. These applications showed that the software can help engineers tooptimize casting process by forecasting casting defect.展开更多
Additive manufacturing is expected to transform and upgrade the traditional foundry industry to realize the integrated manufacturing and rapid and low-cost development of high-performance components with complex shape...Additive manufacturing is expected to transform and upgrade the traditional foundry industry to realize the integrated manufacturing and rapid and low-cost development of high-performance components with complex shapes.The additive manufacturing technology commonly applied in casting mold preparation(fusible molds,sand molds/cores and ceramic cores)mainly includes selective laser sintering(SLS)and binder injection three-dimensional printing(3DP).In this work,the research status of SLS/3DP-casting processes on material preparation,equipment development,process optimization,simulation and application cases in aerospace,automotive and other fields were elaborated.Finally,the developing trends of the additive manufacturing technology in the future of foundry field are introduced,including multi-material sand molds(metal core included),ceramic core-shell integration and die-casting dies with conformal cooling runners.展开更多
文摘Chongqing Zhicheng Machinery Factory One of the Top 10 Chinese Casting Enterprises in 2006 Basic informationAdd: Jiulong Town, Jiulongpo District, Chongqing 400051, China General Manager: Sun
基金Project(2011006B)supported by the Open Project of National Engineering Research Center of Near-Shape Forming for Metallic Materials,ChinaProject(FJ)supported by the CAS"100 talents"Plan
文摘A numerical model of foundry filling process was established based on the smoothed particle hydrodynamics（SPH）method.To mimic the constraints that the solid mold prescribes on the filling fluid,a composite treatment to the solid boundaries is elaborately designed.On solid boundary surfaces,boundary particles were set,which exert Lennard-Jones force on approaching fluid particles;inside the solid mold,ghost particles were arranged to complete the compact domain of near-boundary fluid particles.Water analog experiments were conducted in parallel with the model simulations.Very good agreement between experimental and simulation results demonstrates the success of model development.
文摘本文介绍了VMware近期新推出的一个开源PaaS项目:Cloud Foundry。PaaS是Platform as a Service的缩写,意思是平台即服务。PaaS将软件部署,运行和维护整合成一种服务,以SaaS(Software as a Service软件即服务)的模式提交给开发人员。开发人员可以快速地在其上进行软件开发部署,运行和扩展,而不用去搭建和维护硬件设施,安装软件中间件。将开发人员从软件部署,运行和维护软件的工作中解脱出来。本文指出了现代软件系统的新特点及遇到的挑战,介绍了PaaS的概念、Cloud Foundry的架构,分析了Cloud Foundry与业界现有几款PaaS相比的优点。最后,对PaaS未来的发展方向做了展望。
基金supported by the Program for New Century Excellent Talents in University(No.NCET-09-0396)the Fundamental Research Funds for the Central Universities(2011TS039)+1 种基金the National Science&Technology Key Projects of Numerical Control(2012ZX04012-011)the HUST self-determined and Innovative Research Funds for National Defense(2011)
文摘PPDB issues-four aspects of current management issues of foundry enterprises are discussed in this paper,including Production Management,Process Control,Duration Monitoring and Business Intelligence Data Analysis.Also a whole Enterprise Resource Planning(ERP) solution for foundry enterprises is proposed.The solution contains many models,four of which are used to solve the PPDB issues.These are called SPDB models,which separately are the Single-piece management model(based on casting lifecycle),Process management model(based on task-driven technology),Duration monitoring model(based on surplus period),and Business intelligence data analysis model(based on data mining).An ERP system for foundry enterprises,named HZERP,was researched and developed,and applied to a sand casting company of single piece and small batch production.Qualitatively and quantitatively comparing the application effect before and after implementing the HZERP system,the result demonstrated that the foundry ERP system based on the SPDB models can help metal casting enterprises achieve the single-piece management,better regulate the production processes,improve production and delivery management,shorten the production cycle,reduce costs,and speed up the capital turnover to a large extent.
文摘Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it （P〈0.01）. Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their cumulative silica exposure （OR-3.00, 95% CI 2.34-3.83）. Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m^3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m^3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m^3 for those with 20 years of employment, or below 0.1 mg/m^3 for those with 30 or 40 years of silica exposure. Conclusions At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthend.
文摘with the development of computer technology, foundry CAE technology has made rapid progress. Commercialsoftware packages of casting process simulation, therefore, have become more and more practical. This paper introducesboth the recent developments and some applications of InteCAST software, a commercial numerical simulation softwarepackage for foundry industry, with more than 120 customers all over the world. The function modules of lnteCAST8.0 andsome new techniques, such as uneven mesh technology for mold filling simulation and numerical mouse technology fordata visualization, were introduced. Several applications on special castings such as investment casting, low pressure diecasting, and high pressure die casting, were given. These applications showed that the software can help engineers tooptimize casting process by forecasting casting defect.
基金the Principle and Method of Integrated Laser 3D Printing of Metal Core-Variable Area Performance Complex Sand Mold(Grant No.U1808216)the Aero Engine and Gas Turbine Major Special Fundamental Research Fund Project(2017-Ⅶ-0008-0102)。
文摘Additive manufacturing is expected to transform and upgrade the traditional foundry industry to realize the integrated manufacturing and rapid and low-cost development of high-performance components with complex shapes.The additive manufacturing technology commonly applied in casting mold preparation(fusible molds,sand molds/cores and ceramic cores)mainly includes selective laser sintering(SLS)and binder injection three-dimensional printing(3DP).In this work,the research status of SLS/3DP-casting processes on material preparation,equipment development,process optimization,simulation and application cases in aerospace,automotive and other fields were elaborated.Finally,the developing trends of the additive manufacturing technology in the future of foundry field are introduced,including multi-material sand molds(metal core included),ceramic core-shell integration and die-casting dies with conformal cooling runners.
