Loss rate concept

Browning, R. L. The Loss Rate Concept in Safety Engineering. New York Marcel Dekker, 1980. 

Browning s (1980) premise, as stated in The Loss Rate Concept in Safety Engineering, is sound As every loss event results from the interactions of elements in a system, it follows that all safety is system safety (12). 

At least one other author expected a more widespread adoption of system safety concepts beyond the use by the military and aerospace personnel and nuclear facility designers. He also had to recognize that it wasn t happening. In The Loss Rate Concept in Safety Engineering, R. L. Browning (1980) wrote ... 

This parameter, the smoke parameter, is based on continuous mass loss measurements, since the specific extinction area is a function of the mass loss rate. A normal OSU calorimeter cannot, thus, be used to measure smoke parameter. An alternative approach is to determine similar properties, based on the same concept, but using variables which can be measured in isolation from the sample mass. The product of the specific extinction area by the mass loss rate per unit area is the rate of smoke release. A smoke factor (SmkFct) can thus be defined as the product of the total smoke released (time integral of the rate of smoke release) by the maximum rate of heat release [19], In order to test the validity of this magnitude, it is important to verify its correlation with the smoke parameter measured in the Cone calorimeter. 

Trisomy 18 (Edwards syndrome) is caused by a nondisjunction event during meiosis that results in a fetus having an extra copy of chromosome 18. Although it occurs in only 1 in 8000 births, it is probably the most common chromosome defect at the time of conception. The dramatic change in prevalence is due to the very high fetal loss rate both before 8 weeks ( 80%) and during the second and third trimesters (-70%). Approximately 25% of affected fetuses have... 

According to the classical concept, the Earth s surface is a sink for stratospheric ozone. This is proved by the fact that a net downward ozone flux was measured in the lower tropospheric layers (e.g. Aldaz, 1969). By assuming a first-order process for ozone destruction and using the above residence time, Junge (1962) estimated that the ozone loss rate is 780 x 106 t yr 1 at the surface. To calculate this rate he... 

In practical terms, an indoor air quality model should provide a reasonable description of the mass balance of the test chamber experiments, trying to address factors such as material emissions, airflows into and out of the chamber and chemical/physical decay or other removal and/or transformation processes of the VOCs. VOC concentrations are increased by emissions within the defined volume of the chamber and by infiltration from external air to the chamber. Similarly, concentrations are decreased by transport via exiting chamber air, by removal to chemical and physical sinks within the chamber air, or by transformation of a VOC to other chemical forms. A general mass balance equation concerning the concentration of a VOC in a test chamber can be written in the form of one or more differential equations representing the rate of accumulation and the VOC gain and loss. This concept for a VOC concentration C (mass units/ m ) in a chamber of volume V (m ) is translated into the following differential equation ... 

It should be noted that, since the leading concept of the fusion power-plant system with V-alloys uses liquid Li as coolant and tritium-breeder, the majority of the corrosion and compatibility studies have been oriented to those with liquid Li. Although V is susceptible to oxidation at high temperature, oxidation is not an issue in liquid Li because of high O affinity of Li. A corrosion test using a mono-metallic thermal convection Li loop made of V-4Cr-4Ti pipes, conducted at 700°C for 2355 h, showed the corrosion loss rate corresponded to only <1 pm/year [26]. 

The selection of materials to be used in design dictates a basic understanding of the behavior of materials and the principles that govern such behavior. If proper design of suitable materials of construction is incorporated, the eqiiipment should deteriorate at a uniform and anticipated gradual rate, which will allow scheduled maintenance or replacement at regular inteivals. If localized forms of corrosion are characteristic of the combination of materials and environment, the materials engineer should still be able to predict the probable life of equipment, or devise an appropriate inspection schedule to preclude unexpected failures. The concepts of predictive, or at least preventive, maintenance are minimum requirements to proper materials selection. This approach to maintenance is certainly intended to minimize the possibility of unscheduled production shutdowns because of corrosion failures, with their attendant possible financial losses, hazard to personnel and equipment, and resultant environmental pollution. 

The Cv Concept. From a quantitative standpoint, steam loss can be estimated through the application of the C, concept. A familiar term in control valve technology, C, expresses the flow capability of a fluid-controlling device—in this case, a steam trap. A large C,. means a high flow rate a low C, means a low flow rate. 

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