Source strength

The next significant cycle is the weekend-weekday cycle. This is entirely a source strength cycle associated with the change in the pattern of living on weekends as compared with weekdays. 

Finally, there is the seasonal cycle associated with the difference in climate and weather over the four seasons—winter, spring, summer, and fall (Fig. 4-3). The climatic changes affect source strength, and the weather changes affect transport and diffusion. 

Step 1 - Determine the pollutant quantity source strength... 

Kunkei, B. A., 1983, A Comparison of Evaporative Source Strength Models for Toxic Chemical Spills , AFGL-TR83-0307, ADA139431. 

Numerical simulation of hood performance is complex, and results depend on hood design, flow restriction by surrounding surfaces, source strength, and other boundary conditions. Thus, most currently used method.s of hood design are based on experimental studies and analytical models. According to these models, the exhaust airflow rate is calculated based on the desired capture velocity at a particular location in front of the hood. It is easier... 

FIGURE 8.1 Model of a central recirculating system used for calculating the connection between contaminant concentrations, airflow rates, contaminant source strength, q, and air cleaner efficiency, rj. Cj p is the concentration in the supply (outside) air, c is the concentration in the room, c is the concentration in the returned air, (JaMot the total flow rate through the room, ic is the ratio between recirculated airflow rate and total air flow rate, T is the time constant for the room, and V is the room volume. 

VOCs are released during chemical cleaning of bonding surfaces. The extract system is designed on the basis of the steady-state concentration determined for maximum source strength and considering the mechanical extract ventilation only and no air-exchange with the assembly hail. Ehis concentration must be kept below the threshold concentration (TVL) which is set to 300 mg/kg in this example. 

I FIGURE li.45 Schedule values for a 24 h time period for containmeril source strength (nominal value 0.6 t< /h). 

The volume-source method is not only useful in a spherical approach, but can also be used in more arbitrary geometries, where it is possible to express the volume source strength in a product of burning velocity and flame surface area ... 

This concept can be generalized for more arbitrarily shaped clouds, provided that a reasonable estimate can be made of combustion process development in terms of burning velocity and flame surface area. According to Strehlow (1981), a conservative estimate of source strength is made by... 

Assuming that a source produces its total volume within S-ir seconds during flame passage, the volume source strength, V, may be expressed in a suitable function ... 

A safe and most conservative estimate of the strength of the sources of strong blast can be made if a maximum strength of 10 is assumed. However, a source strength of 7 seems to more accurately represent actual experience. Furthermore, for side-on overpressures below about 0.5 bar, no differences appear for source strengths ranging from 7 to 10. 

The expressway may be considered to be a continuous infinite line source. To obtain a source strength q (in g/s-m), tlie number of vehicles per meter of highway must be calculated and multiplied by the emission per vehicle. 

Suppose now that the source strength is suddenly changed to a new value Qi. How long would it take for the reservoir to reach a new steady state The adjustment process is described by the differential equation... 

Alternatively, we could organize the list by variability in which we would see that N2, O2, and the noble gas concentrations are extremely stable, with increasing variability for substances of low concentration and for chemically reactive substances. Both the temporal and spatial variability are influenced by the same factors source strength and its variability, sink mechanisms... 

Radiation monitors are continually employed to detect any radiation leakage during operation or source storage, and to confirm a return to satisfactory background levels within the sterilization chamber following operation. The dose delivered is dependent upon source strength and exposure period, with dwell times typically up to 20 hours duration. 

To minimize experiment time a very strong Co/Rh source was used, with an initial source strength of about 350 mCi at launch. Instrument internal calibration is accomplished by a second, less intense radioactive source mounted on the end of the velocity transducer opposite to the main source and in transmission measurement geometry with a reference sample. For further details, see the technical description in Sect. 3.3. 

The key point to remember, in the merits of year-round radon removal, is that there is no guarantee that radon problems will not be present even in the summer months. The radon levels found in individual houses are a complex result of radon source strength, soil transport, the number, size, and location of entry points, weather, and the way the house is operated.2 To be certain of maintaining low radon levels in the house normally requires that an SSD mitigation system works properly 24 h per day, 365 days per year. It is for this reason that durability and system performance are very important considerations. The performance level goal for the system is 100% on-time operation for the life of the building. This requires excellent durability of system components and a reliable means for determining whether the system is fully operational at all times. 

The factor k (the transfer factor) was defined as a crop- and task-specific factor and is defined as the slope of the line that fits dermal exposure levels (g/hr) and corresponding levels of DFR (g/m2) on the crop (i.e., the regression coefficient of DFR). The DFR, according to the procedures described by Iwata et al. (1977), was considered to be a good estimate of source strength for re-entry exposure. 

Brouwer, D.H., de Haan, M., Peelen, S., van de Vijver, L., and van Hemmen, J.J. (1994) Dislodgeable foliar residue as an estimate of source strength for worker exposure to pesticides, in Book of Abstracts from the 8th International Congress of Pesticide Chemistry, American Chemical Society/IUPAC, July 4r-9. 

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