Damage function

A commonly used measure of irradiation damage is displacements per atom (dpa). A unit of 1 dpa means that on the average, every atom in the irradiated volume has been displaced once from its equiUbrium lattice site. The approximated dpa in the implanted region is given by equation 16 where 0 (ions/cm ) is the dose, and (NJE)) is the damage function given by equation 14. 

How would one go about developing an air pollution damage function for human health ... 

The main trouble with IPM in its presently adopted forms is how to determine the threshold beyond which an intervention is warranted, since the threshold depends on a multitude of factors such as pest population and its likely increase, the intensity of predators and their likely increase, crop damage functions for individual... 

Displacement damage function, 14 436 Displacement desorption, factors governing choice of method, l 614t Displacement plating, 24 141 Displacements per atom (dpa), 14 436 Displays... 

The results of these experiments suggest that overall economic effects on agricultural production could be extensive, depending on the sensitivity of cultivars used in production, and should be considered in the attempt to arrive at valid economic-damage functions for vegetation. 

HN03 may damage polycondensation cation exchangers, easily damages functional groups of anion exchangers. 

There are indications that the magnitude of the DC limit measured in an impedance experiment correlates with the performance of anodized surfaces in cabinet exposure tests. On this basis, it is possible to define a damage function, D, as the logarithm of the ratio of the impedance, taken at 0.1 Hz at zero exposure time, to that at some exposure time, t (109). 

At this frequency, the magnitude of the impedance will decrease with increasing exposure time, so the damage function should increase with time. In principle, this measurement could be made using a single-frequency admittance-type approach, but collection of the spectrum at higher frequencies than 0.1 Hz can be made with little additional measurement time penalty. 

Fig. 27 Integrated damage functions (crack length) versus reactor operating time for three operating scenarios (1) normal water chemistry,...

An important consequence of acid rain and dry deposition of SO2 and HNO3 is the rapid weathering and destruction of exposed carbonate stone buildings and monuments (cf, Baedecker et al. 1990). Lipfert (1989) has proposed a theoretical damage function equation to describe the weathering of carbonate stone between pH 3 and 5, which is... 

Lipfert, F, W. Benarie, M. Daum, M. L. Derivation of Metallic Corrosion Damage Functions For Use in Environmental Assessments. Draft Report, available from senior author. Dept, of Energy and Environment, Brookhaven National Laboratory, Upton, NY 11973. 

The full methodology of retrospective analysis was applied for the case of marble tombstone deterioration in an urban and a remote cemetery near New York City (8,9). In this exercise it was found that our technique may estimate rural SO2 concentrations acceptably well, but it does not reproduce detailed structure of urban concentrations adequately. The main reasons are uncertainty about the effective release heights of sources and a lack of detailed local emission Information. For the purposes of metal corrosion, the current state of the retrospective reconstruction of environmental histories is not sufficiently quantitative to warrant extraction of damage functions. 

A project was undertaken to perform retrospective reconstruction of environmental histories at the sites of previous long term atmospheric metal exposures. The effort required development of appropriate emission information and dispersion modeling capabilities on both the regional and urban spatial scales. The development of useful urban scale emission inventories dating back several decades proved to be a limiting factor. At present, therefore, the retrospective reconstruction of environmental histories is not possible for the large number of sites in the metals corrosion data base. This precludes derivation of damage functions at this time. 

Corrosion rate was evaluated with respect to, 1) flux of pollutants (sulfur oxides, nitrogen oxides, oxidants, and particles) to the steel during both wet and dry periods, 2) temperature, and 3) exposure history. Different definitions of when the steel was wet were evaluated to determine the most likely "critical relative humidity." Non-linear multiple regression techniques were used to determine the statistical significance of each factor and develop a theoretically consistent environmental damage function. 

Variables are listed in the order in which they were entered into the regression. The resulting damage function... 

Tremper (27) developed a damage function to describe the deterioration observed in his work. The damage function, which is expressed as... 

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