Philosophy of protection

A key but vexing question in any consideration of the philosophy of wood preservation must be how long a piece of treated wood should last. It is apparent that no one specific time frame exists. 

In recognition that the deterioration hazard varies with end-use, many countries have developed hazard class or use category systems that specify those preservative formulations that are suitable in particular situations, the amount of preservative to be used (its retention ), and the depth to which the preservative must penetrate the wood (Morrell and Preston, 1995) (Table 9.2). As might be expected there is considerable overlap between these end-use categories. 

End use, relative hazard Principal hazard Choice of timber Condition of timber Choice of preservative Quantity of preservative uptake Treatment process 

Wood preservatives are generally classified or grouped by the type of application or exposure environment in which they are expected to provide long term protection. Some preservatives have sufficient leach resistance and broad-spectrum efficacy to protect wood that is exposed directly to soil and water. These preservatives will also protect wood exposed above ground, and may be used in those applications with lower retentions (lower concentrations in the wood). Yet other preservatives have intermediate toxicity or leach resistance. This allows them to protect wood that is fully exposed to the weather, but not in contact with the ground. Other preservatives lack the permanence or toxicity to withstand continued exposure to precipitation, but 

It is not possible to evaluate a preservative s long term efficacy in all exposure environments. Preservatives have been tested most extensively in ground contact only, and there is no perfect formula for adjusting or predicting how well a wood preservative might perform in another situation. This is especially true for aboveground applications. To compensate for this uncertainty, there is a tendency to be conservative when selecting a preservative for a particular application. 

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The first task in applying a spacing table to a facility is to ensure it corresponds to the philosophy of protection adopted by the company. Where limited space is available to provide the required spacing, an examination of the equivalent fire and explosive barriers or active fire suppression system should be confirmed. This analysis should be accepted by the company as part of the design risk analysis. 

Before the need of fire protection measures is defined, the type of hydrocarbon fire exposure should be identified. By determining the type of fire expected, the adequacy of the fire protection measures based on the philosophy of protection for the facility, can be assessed. The easiest method to arrive at the protection requirements is to identify the materials and pressures involved in the process. Once this is accomplished, the most appropriate fire control or suppression mechanism can be identified from NFPA 325M. Tables 3 and 4 provides examples of a tabular format that can be used to document the fire control mechanisms that have been chosen. 

The Team Leader is not responsible to produce any recommendations. He is to guide the team in the review to arrive at a consensus of what is the required level of protection desired for the facility. In this respect the Team Leader can suggest methods of protection commonly employed by the company s philosophy of protection or applied in the petroleum or chemical industries. All recommendations should be arrived at via a consensus of the team review members. 

The risk management techniques of the organization should be defined before any considerations of the philosophy of protection needs for a facility are identified. An organization that is capable of obtaining a high level of insurance coverage at very low expense, even though they may have risks, may opt to have a limited outlay for protection measures since it is not cost effective. In reality this would probably never occur, but serves to demonstrate influences in a corporate approach to protection levels and risk acceptance criteria. 

To achieve safety objectives and a philosophy of protection through independent layers of protection, a project or organization should define specific guidelines or standards to implement in its designs. Numerous industry standards are available (i.e., API, CCPS, NFPA) that provide options, general recommendations, or specific criteria once a design preference is chosen. It is therefore imperative to have company-specific... 

What is the maintenance philosophy of the system This dictates what sort of protection schemes and physical design would match the application. 

The philosophy of public health protection used by the AEC and pursued ever since, is the use of multiple independent barriers, each a significant shield for the public. The last barrier involves the removal of people from the area over which the radioactive plume is expected to pass, interdiction of food supplies and the use of prophylaxis to reduce the iodine dose. Blood... 

Due to the destructive nature of hydrocarbon forces when handled incorrectly, fire and explosion protection principles should be the prime feature in the risk philosophy of any hydrocarbon facility. Vapor cloud explosions in particular are consider the highest risk at a hydrocarbon facility. Disregarding the importance of protection features or systems will eventually prove to be costly both in economic and human terms should a catastrophic incident occur without adequate safeguards. 

Depressurization and Blowdown Capabilities - A mathematical calculation of the system sizing and amount of time needed to obtain gas depressurization or liquid blowdown according to the company s philosophy of plant protection and industry standards (i.e., API RP 521). 

The Product Stewardship philosophy of the Dow Chemical Co. is described. It is a management practice committed to making health, safety and environmental protection an integral part of every stage of a product s life. The implementation of a multi-level training and auditing programme is discussed. 3 refs. 

This difference in philosophy of who is to be protected by a particular regulation, the public or the worker, actually works to ensure that both are protected. This is the case because facilities affected by RMP generally are also affected by the requirements of PSM. Simply stated, by complying with the requirements of each regulation, both the pubic and the worker will be protected—and the environment benefits as well. 

One astute way to obtain macrocyclic systems with TTF is the stepwise method of deprotection/alkylation of cyanoethyl-protected TTF-thiolates. With this method molecular units can be built but with the precaution of preserving one cyanoethyl group in order to be able to iteratively proceed with the oligomerization. Combining such units, larger units can be produced. An example of a TTF dendrimer containing 21 TTFs is shown in Fig. 2.15 (Christensen et al, 1998). Here only the main philosophy of the synthesis is discussed. 

Unexpected Benefits. Of the fifteen responding firms, R D officers from only five firms report tangible benefits that are not directly related to environmental protection. These benefits include better analytical chemists closed system philosophy of plant operation improved knowledge of molecular structure of products and better process instrumentation. 

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