Ethylene material factor

It is necessary to determine the bioburden and make cycle verification studies when ethylene oxide sterilization is used, as it is for other sterilization methods. The manufacturer of hospital sterilization equipment provides cycle recommendations based on the expected bioburden and the consideration of an appropriate safety factor. In ethylene oxide sterilization, it is necessary to determine if residues of the stefilant are absorbed by the sterilized article, and to examine the possible formation of other potentially toxic materials as a result of reaction with ethylene oxide. 

As an example, the battery-limits capital cost can be estimated for the production of 10,000 t/yr of ethylene (qv) from ethanol (11). Seven processing blocks, ie, vaporizer, reactor, water quench, compressor, dryer, distillation, and energy recovery, can be identified. The highest temperature is 350°C (reactor), and the highest pressure is about 1.7 MPa (17 atm) (compressor, two towers). If a materials-pressure factor, + of 1.03 is assumed, then for N = 7 0 = 0.87 1/0 = 1 64 and f =0 K = 6.3. This gives the 1981 cost as 4.4 X 10 . The 1991 battery-Hmits investment can be obtained, by updating with the CE Plant Cost Index, as 5.3 x 10 . ... 

The equivalent charge weight of TNT is calculated on the basis of the entire cloud content. FMRC recommends that a material-dependent yield factor be applied. Three types of material are distinguished Class I (relatively nonreactive materials such as propane, butane, and ordinary flammable liquids) Class II (moderately reactive materials such as ethylene, diethyl ether, and acrolein) and Class III (highly reactive materials such as acetylene). These classes were developed based on the work of Lewis (1980). Energy-based TNT equivalencies assigned to these classes are as follows ... 

Vapor Cloud Explosions. Lenoir and Davenport (Ref. 16) have summarized some major VCEs worldwide from 1921 to 1991. The materials involved in these incidents suggest that certain hydrocarbons—such as ethane, ethylene, propane, and butane—demonstrate greater potential for VCEs. Several factors may contribute to these statistics. These materials are prevalent in industry and are often handled in large quantities, increasing the potential for an incident. Certain inherent properties of the materials also contribute to their potential for explosion. These include flammability, reactivity, vapor pressure, and vapor density (with respect to air). 

Hazards attendant on use of ethylene oxide in steriliser chambers arise from difficulties in its subsequent removal by evacuation procedures, owing to its ready absorption or adsorption by the treated material. Even after 2 evacuation cycles the oxide may still be present. Safety is ensured by using the oxide diluted with up to 90% of Freon or carbon dioxide. If high concentrations of oxide are used, an inert gas purge between cycles is essential [7], The main factors in safe handling... 

A variety of materials are used when manufacturing a cover, including reinforced concrete, steel, aluminum, polypropylene, chlorosulfonated polyethylene, or ethylene interpolymer alloys. There are several factors that affect a reservoir cover s effectiveness and thus its ability to protect the stored water. These factors include the following ... 

Any material proposed for implantation, whether for cell transplantation or some other application, must be biocompatible i.e. it must not provoke an adverse response from the host s immune system. If this goal is not met the implant may be rejected. To this end it is important that the material be easily sterilized either by exposure to high temperatures, ethylene oxide vapor, or gamma radiation. A suitable material must therefore remain unaffected by one of these three techniques. However, biocompatibility is not simply a question of sterility. The chemistry, structure, and physical form of a material are all important factors which determine its biocompatibility. Although our understanding of the human immune system is advancing rapidly, it is not yet possible to predict the immune response to a new material. This can only be determined by in vivo experiments. 

Perhaps the most important of these factors involves the raw material employed for this purpose and the by-product volumes and prices. In this connection we discuss the product distributions from potential various feedstocks and current trends in feedstock selection, illustrating the significant role feedstocks play in the ethylene commercial picture. In addition, the effects on production economics of the factors of plant size and severity of operation are investigated. 

Potential packing materials for nucleic acid chromatography have hydrophobic and weakly cationic sites. Figure 22 shows the logarithmic retention factors of oligo-adenylyl phosphates on an ion-exchange column (100x4.6 mm) with ethylene di-... 

These reactions are driven by a combination of factors, including a loss of ring strain or the release of a volatile olefin such as ethylene. They can also be kinetically controlled by the formation of a less reactive carbene complex. An important feature of RRM is the catalytic transfer of stereocentres from the corresponding substituted carbocycles, i.e. the chirality embedded in the carbocyclic starting material is completely transferred to the product side chain. This allows chirality to be introduced by means of side chains at the carbocycle. Synthetically, this... 

---