Kinetics of the aeration of ethylene-oxide sterilized plastics.
The aeration of ethylene-oxide (EO) sterilized medical plastic materials is dealth with mathematically, and subsequently the model found is used for calculation of the EO diffusion coefficient in various plastics with the composition and temperature as variables. Absorption and dissolution of EO in various plastic materials are measured at varying concentrations of EO, temperatures and compositions of plastics. The mathematical model is used to evaluate the EO desorption from medical devices under different physico-chemical conditions as well as in vivo. EO analysis methods are evaluated on the basis of the model and are compared with experimental results.
General solution of the diffusion equation: application to formaldehyde sterilization and desorption of polymers.
A general solution of the diffusion equation for gas in polymers is developed by a numerical method. This solution allows diffusion to be calculated in all cases, by gas desorption after an incomplete adsorption, which is not the case for analytical solutions. When the analytical solutions are valid, both types of solution give identical results. The effect of equivalent sterilization treatment at different temperatures and gas concentrations on formaldehyde residuals in 9 polymers is calculated. High temperature gives lower residual content. Short sterilization times at high gas concentration produce a higher residual content at the end of the adsorption and a lower residual content during desorption than longer sterilization times with lower gas concentration. This is due to sharper gradients of diffusant in the polymer.
Development of Science and Technology in the Iranian Electric Power Industry: Challenges and Future Progress
This chapter examines four key segments of the electric power industry in Iran: generation, transportation, distribution and consumption. It reviews the method, development, and evolution of electric power generation in the country. Specifically, the chapter reviews the structure of the electric industry, the main players, institutions, standards as well as laws, human resources, technology, the export and import markets, and engineering management of the industry in the country. Finally, the challenges facing the industry will be identified and policy suggestions to remedy the problems will be provided.