Transport estimating

The discrete distance option of SCREEN allows the user to input specific distances. Any number of distances (s 1 meter) can be input by the user and the maximum concentration for each distance will be calculated. The user will always be given this option whether or not the automated distance array option is used. The option is terminated by entering a distance of zero. SCREEN will accept distances out to 100 km for long-range transport estimates with the discrete distance option. However, for distances greater than 50 km, SCREEN sets the minimum 10 meter wind speed at 2 m/s to avoid unrealistic transport times. 

Cadwell, L.L., R.G. Schreckhise, and R.E. Fitzner. 1979. Cesium-137 in coots (Fulica americana) on Hanford waste ponds contribution to population dose and offsite transport estimates. Pages 485-491 in Low-Level Radioactive Waste Management Proceedings of Health Physics Society. Twelfth Midyear Topical Symposium. February 11-15, 1979, Williamsburg, VA. 

One major difficulty in assessing the accuracy of any transport simulation method is the inaccuracy in runoff estimations. The basin selected for the study described was of minimum size for application of the Stanford watershed model. This is reflected in the corresponding uncertainties in all computations. However, it is worth noting that the measured and simulated concentrations of Sr and 137Cs seldom differed by more than a factor of two. This observation suggests that increasing the accuracy of simulated runoff processes will result in an increased accuracy in radioaerosol transport estimates as well. 

Lynch-Stieglitz J., Curry W. B., and Slowey N. (1999a) A geostrophic transport estimate for the Florida Current from the oxygen isotope composition of benthic foraminifera. Paleoceanography 14, 360-373. 

The resistance of a single unit is near 2000-10 fi. A potential difference of 100 mV across this resistance could drive ions at a rate of 500-10 ions/s, a value greater than the maximum rate of transport estimated for certain carriers. 

If the effectiveness factor of the catalyst is 0.42, the reaction obeys flrst-order kinetics, and Knudsen diffusion is the dominant mode of molecular transport, estimate the... 

If these assumptions are satisfied then the ideas developed earlier about the mean free path can be used to provide qualitative but useful estimates of the transport properties of a dilute gas. While many varied and complicated processes can take place in fluid systems, such as turbulent flow, pattern fonnation, and so on, the principles on which these flows are analysed are remarkably simple. The description of both simple and complicated flows m fluids is based on five hydrodynamic equations, die Navier-Stokes equations. These equations, in trim, are based upon the mechanical laws of conservation of particles, momentum and energy in a fluid, together with a set of phenomenological equations, such as Fourier s law of themial conduction and Newton s law of fluid friction. When these phenomenological laws are used in combination with the conservation equations, one obtains the Navier-Stokes equations. Our goal here is to derive the phenomenological laws from elementary mean free path considerations, and to obtain estimates of the associated transport coefficients. Flere we will consider themial conduction and viscous flow as examples. 

From polarization curves the protectiveness of a passive film in a certain environment can be estimated from the passive current density in figure C2.8.4 which reflects the layer s resistance to ion transport tlirough the film, and chemical dissolution of the film. It is clear that a variety of factors can influence ion transport tlirough the film, such as the film s chemical composition, stmcture, number of grain boundaries and the extent of flaws and pores. The protectiveness and stability of passive films has, for instance, been based on percolation arguments [67, 681, stmctural arguments [69], ion/defect mobility [56, 57] and charge distribution [70, 71]. 

Carbonic anhydrase is an enzyme that catalyzes the hydration of carbon dioxide to bicarbonate The uncatalyzed hydration of carbon dioxide is too slow to be effective m transporting carbon dioxide from the tissues to the lungs and so animals have devel oped catalysts to speed this process The activity of carbonic anhydrase is remarkable It has been estimated that one molecule of this enzyme can catalyze the hydration of 3 6 X 10 molecules of carbon dioxide per minute... 

Existing methods for monitoring the transport of gases were inadequate for studying aerosols. To solve the problem, qualitative and quantitative information were needed to determine the sources of pollutants and their net contribution to the total dry deposition at a given location. Eventually the methods developed in this study could be used to evaluate models that estimate the contributions of point sources of pollution to the level of pollution at designated locations. 

Production and Shipment. Estimated adiponitrile production capacities in the U.S. in 1992 were about 625 thousand metric tons and worldwide capacity was in excess of lO metric tons. The DOT/IMO classification for adiponitrile is class 6.1 hazard, UN No. 2205. It requires a POISON label on all containers and is in packing group III. Approved materials of constmction for shipping, storage, and associated transportation equipment are carbon steel and type 316 stainless steel. Either centrifugal or positive displacement pumps may be used. Carbon dioxide or chemical-foam fire extinguishers should be used. There are no specifications for commercial adiponitrile. The typical composition is 99.5 wt % adiponitrile. Impurities that may be present depend on the method of manufacture, and thus, vary depending on the source. 

The use and effective costs of various energy alternatives are shown in Table 2. Use or internal costs include production, transportation, and distribution. Effective costs take into account the use costs estimated external costs, which include costs associated with damage to the environment caused by utili2ation of various fossil fuels and fuel utili2ation efficiencies, ie, the efficiency of converting fuels into mechanical, electrical, or thermal energy. The effective costs are expressed as /GJ of fossil fuel equivalent (15). The overall equation for the effective cost is... 

If possible comparisons are focused on energy systems, nuclear power safety is also estimated to be superior to all electricity generation methods except for natural gas (30). Figure 3 is a plot of that comparison in terms of estimated total deaths to workers and the pubHc and includes deaths associated with secondary processes in the entire fuel cycle. The poorer safety record of the alternatives to nuclear power can be attributed to fataUties in transportation, where comparatively enormous amounts of fossil fuel transport are involved. Continuous or daily refueling of fossil fuel plants is required as compared to refueling a nuclear plant from a few tmckloads only once over a period of one to two years. This disadvantage appHes to solar and wind as well because of the necessary assumption that their backup power in periods of no or Httie wind or sun is from fossil-fuel generation. Now death or serious injury has resulted from radiation exposure from commercial nuclear power plants in the United States (31). 

The transport of phthalates by road tankers and ships within Europe is carried out by international companies with sophisticated tank cleaning facihties. Wash waters from these modem faciUties are passed through a series of separators to remove any residual plasticizer which is then incinerated. It is estimated that, as a result of cleaning and spillages, the maximum emission to the environment is 80 t/yr. 

---