Sources, characteristics

natural sources often have a distinctly different character than anthropogenic sources, which are comparably constant with respect to seasonality. In addition, the source strength as well as the spatial distribution of natural sources may differ substantially from year to year. An extreme example is voleanic emission. 

An emission (and deposition) represents a flux (mass per time). Concerning the source characteristics, we separate emissions from 

diffuse sources (surfaces such as soils, lakes, landscapes etc.). 

The flux can be related to an area (a standard area such as ha and m ) and is then termed a specific emission. The matter state is 

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Leak or spill source Characteristics Root causes Preventive measures... 

Source Characteristics of sources and calculations methods Calculation models... 

In theory it should be possible to calculate the capture efficiency without measurements. Some attempts have used computational fluid dynamics (CFD) models, but difficulty modeling air movement and source characteristics have shown that it will be a long time before it will be possible to calculate the capture efficiency in advance. ... 

Simple Evaluation A simple evaluation can be done by checking the airflow rate into the opening, presuming the source characteristics, the placing of the exhaust, and the other parameters (cross-draft, work routines, supply airflow rate, etc.) have not changed since the detailed evaluation was done. It is necessary to do the simple evaluation at the same time as the detailed evaluation. The flow... 

Data analysis should focus on the development or refinement of the conceptual site model by analyzing data on source characteristics, the nature and extent of contamination, the contaminants transport pathways and fate, and the effects on human health and the environment. All field activities, sample management and tracking, and document control and inventory should be well managed and documented to ensure their quality, validity, and consistency. 

Other source conditions. The source height and the source area are also important source characteristics. The greatest impact is typically associated with ground-level sources, so elevated sources are not considered in the model discussion below. 

Independent power source Characteristics of the plant are as follows ... 

Hosier, S., S. K. Friedlander, and R. B. Husar. The relationship of smog aerosol size and chemical element distributions to source characteristics. Atmos. Environ. 7 633-649, 1973. 

First, the availability of high optical throughput in an FT-NlR analyzer means that lower-cost, more robust and also more linear DTGS detectors can be used routinely. These in turn allow (through the choice of suitable beamsplitter materials and source characteristics) a wider range of operation than the conventional... 

Sharma, M., Basu, A.R., Nesterenko, G.V. 1992. Temporal, Sr-, Nd- and Pb-isotopic variations in the Siberian flood basalts implications for the plume-source characteristics. Earth and Planetary. Science Letters, 113, 365-381. 

Relatively large deviations from the general equation are evident when monthly data for individual stations are considered (Table 3.1). In an extreme situation, represented by the St. Helena station, a very poor correlation between 8D and 5 0 exists. At this station, it appears that all precipitation comes from nearby sources and represents the first stage of the rain-out process. Thus, the generally weaker correlations for the marine stations (Table 3.1) may reflect varying contributions of air masses with different source characteristics and a low degree of rain-out. 

It is dispersed by wind and removed by gravitational settling (sedimentation), dry deposition (inertial impaction characterized by a deposition velocity), washout by rain (attachment to droplets within clouds), and rainout (scrubbing action below clouds) (Schroeder et al. 1987). The removal rate and distance traveled from the source depends on source characteristics (e.g., stack height), particle size and density, and meteorological conditions. 

A source apportionment study using the receptor model should include interpretation of the chemical data set by both multivariate and chemical mass balance methods The most critical steps in a receptor model study are the initial review of potential source characteristics and the development of an appropriate study plan. 

For receptor modeling, the only source characteristics that are relevant are those perceived at the receptor. But if source components could be separated from each other at the receptor, there would be no need for a receptor model. 

A promising development is that reported by Rheingrover and Gordon (30). Using ambient samplers located in "maximum effect" areas for specific sources and wind flow patterns, they have distinguished the composition of a single point source a a receptor. They then use these source characteristics to represent that source in areas less affected by that source, where its contribution is not so obvious. 

Morawska and co-workers have produced a number of review articles on this topic. For example, Holmes and Morawska [20] reviewed several simple and complex models covering a wide range of urban scales for the dispersion of particulate matter. Morawska et al. [21] focused on vehicle produced ultrafine particles and discussed limitations of measurement methods, sources, characteristics, transport and exposure of these particles in urban environments. Their further review focused on indoor and outdoor monitoring of airborne nanoparticles [3]. Morawska [22] discussed the importance of airborne ENPs from the health perspective. Regulations and policy measures related to the reduction of ambient particulate matter were discussed in their follow-up article [23], Their recent review article discussed the commuters exposure to ultrafine particles and associated health effects [24]. 

In creating a database for a search the source characteristics and the desired product profile are natural poles on the matrix axes. Other considerations need then to be layered into the search pattern. Two such considerations might be geography or historical activity. These can be good pointers as to where to search, particularly... 

Source/Characteristic Interbed sandstone Interbed sandstone/ claystone Interbed tuff... 

Table III Comparison of Vibrational Raman Scattering Fluctuation Measurement Capabilities for Different Laser Source Characteristics.

Short-circuit current — It is the current supplied by an electrical -> power source device if the two terminals of the device are connected, without associated dissipation -> resistance, i.e., load resistance equal to zero. The short-circuit current is determined by the power source characteristics, given by the quotient between electromotive force and internal resistance. See also -> fill factor. 

Handbook of Isotopic Power Source Characteristics, Arnold, ORNL 3576 Oak Ridge National Laboratory, Oak Ridge TN, 1964. 

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