When formulating a mathematical model for simulating transport processes in the environment, the system of interest can be viewed as a continuum of matter and energy or as a large set of small discrete parcels of mass and energy. The latter approach is used in the formulation of the Discrete-Parcel-Random-Walk (DPRW) Transport Model. Each parcel has associated with it a set of spatial coordinates as well as a set of discrete quantities of mass and energy. A parcel's movement is assumed to be independent of any other parcel in the system. A Lagrangian scheme is used for computing the parcel advection and a Markov random walk concept is used for simulating the parcel diffusion and dispersion. The DPRW technique is not subject to numerical dispersion and it can be applied to three-dimensional cases with only a linear increase in computation time. A wide variety of complex source/sink terms can be included in the model with relative ease. Examples of the model's application in the areas of oil spill drift forecasting, coastal power plant effluent analysis, and solute transport in groundwater systems are presented.

This report presents a profile of 1972 transportation energy consumption in the Northeast region. Transportation energy projections for the region are given by mode for the years 1985 and 2000. Conservation actions which could significantly affect future transportation energy demand levels are described and their impacts evaluated. It is estimated that while the demand for energy in the transportation sector might increase by as much as 88% by the year 2000, strong conservation actions could reduce the projected level of demand by over 30%. Recent changes in the growth and distribution of population and industrial and commercial activities are reviewed. Both the factors that affect these growth and distribution patterns and the implications of changes in existing patterns on energy use in the transportation sector are discussed. It is shown, for example, that land-use controls could substantially reduce the growth of energy demand in the transportation sector. Finally, conservation actions are discussed within the context of how they might be implemented by Federal, State, or local governments. Interactions between actions are discussed and groupings of actions that minimize the disadvantages of individual actions while taking advantage of complementary effects between actions are presented.

A guide for the use of the CDC-6400 Computer Program TWO-STEP for the exact solution of linear matrix equations over the integral domain is given. The rational result is converted into decimal form to 12 decimal places.

Differential cross sections for the neutron-induced gamma-ray production from natural vanadium have been measured for incident neutron energies between 0.2 and 20.0 MeV. The Oak Ridge Linear Accelerator (ORELA) was used to provide the neutrons and a NaI spectrometer to detect the gamma rays at 125/sup 0/. The data presented are the double differential cross section, d/sup 2/sigma/d..cap omega..dE, for gamma-ray energies between 0.3 and 10.6 MeV for coarse intervals in incident neutron energy. The integrated yield of gamma rays of energies greater than 300 keV and higher resolution in the neutron energy is also presented. The experimental results are compared with the Evaluated Neutron Data Files (ENDF). 24 figures.

The steady-state CBT/CIT ion velocity distributions are stable to all electrostatic and electromagnetic infinite-medium modes. This stability is due to the large thermal spread of the distributions (T/sub hot/ approximately greater than 1.5 T/sub e/, v/sub ti//u greater than /sup 1///sub 3/), and to the fact that tokamak equilibrium allows the mean streaming velocity, u, to be only a small fraction of the Alfven velocity.

A review of some existing digital simulations of fluid systems, a brief description of the proposed generalized computer code, a description of, and results from, two solution techniques, and a sample test case ventilation system are presented. The review of some fluid system simulations covers methods and techniques for development of a more general digital solution technique than the successive substitution method used in previous analyses. The structure and organization of the computer code under development is discussed. A section dealing with the development of a user-oriented input to the code is also presented. Two solution techniques suitable for solving the simultaneous nonlinear algebraic and differential equations are presented. One of the techniques is based upon a loop method and employs Newton's method for obtaining simultaneous iterative corrections for the solution. The second approach is based upon a node orientation and employs Cross' method to arrive at successive iterative corrections for the solution. Graphical results using both methods are presented. The results are essentially identical. A ''test-case'' ventilation system is introduced. The test-case ventilation system model was developed primarily for ''debugging'' the proposed generalized code. The test case is a simple yet realistic representation of the types of subsystems which …

Water table maps, water table gradient maps, and depth-to-water maps have been constructed for the Nevada Test Site and the Central Nevada Test Area by empirical simulation using a digital computer. Although the digital computer program has been developed specifically for the areas mapped, it is directly applicable to any hydrologic province where ground-water recharge areas occur between the discharge areas such as humid regions and the arid Great Basin of the Western United States. This report presents maps constructed during May 1975, a listing of the water level control points, and a brief description of the empirical mapping technique.

Packaging microwave hybrid microcircuits having combined electrical functions presented challenges in meeting space requirements without excessive signal interaction between microwave networks. The dispersive characteristics of microwave hybrid microcircuits are aggravated by the proximity of conductive materials, which places stringent requirements on packaging space and geometry. A space savings of 15 to 20 percent has been achieved with the wiggly phase shifter and wiggly directional coupler. In addition, the performance of each device has been significantly improved. The VSWR bandwidth of the phase shifter has been doubled, and the directivity of the directional coupler has been increased by 20 dB.