Since their introduction by Barenblatt et al. (1960), double-porosity models have been widely used for simulating flow in fractured reservoirs, such as geothermal reservoirs. In a dual-porosity system, the matrix blocks provide most of the storage of the reservoir, whereas the fractures provide the global transmissivity. Initially, most work on dual-porosity models emphasized the development of analytical solutions to idealized reservoir problems. Increasingly, the dual-porosity approach is being implemented by numerical reservoir simulators. Accurate numerical simulation of a dual-porosity problem often requires a prohibitively large number of computational cells in order to resolve the transient pressure gradients in the matrix blocks. We discuss a new dual-porosity model that utilizes a nonlinear differential equation to approximate the fracture/matrix interactions, When implemented into a numerical simulator, it eliminates the need to discretize the matrix blocks, and thereby allows more efficient simulation of reservoir problems.

A problem situation involving the handling of radioactive material at Argonne National Laboratory -- West (ANL-W) was solved through the use of remote handling techniques, providing significant exposure reduction to personnel. Robotic devices can be useful, but the cost of a robot is often prohibitive for many jobs. A low cost, disposable robot was built which successfully removed a highly radioactive and potentially explosive system from a hot cell at ANL-W.

Plastic crystal behavior is observed in semiconducting CsPb and NaSn at high temperature (600 and 500 C, respectively). This behavior is associated with M{sub 4}{sup 4{minus}} or A{sub 4}M{sub 4} structural units orientationally disordering about 50 C below the melting point where translational disorder sets in. This orientational disorder is different in the two phases, exhibiting jump reorientations in CsPb and a more isotropic behavior in NaSn. In other Zintl compounds such as KPb, there is a single melting point where orientational and translational disorder sets in simultaneously; the classification of the different Zintl compounds into these two different kinds of behavior will require calorimetry or neutron diffraction below the melting point. (DLC)

We present a method for analyzing the annual cooling and lighting electricity use and peak demand associated with varying fenestration and lighting strategies in commercial office buildings. A prototypical office building module consisting of four perimeter zones and a central core zone was defined and a series of DOE-2 building energy simulations were completed to create a data base for varying fenestration and lighting system parameters. Using regression analysis procedures, we characterize energy and peak performance patterns as a function of solar aperture, defined as the product of shading coefficient and window-to-wall ratio, and effective daylighting aperture, defined as the product of visible transmittance and window-to-wall ratio. Optimum performance consists of defining the solar and effective daylighting aperture values that minimize annual energy consumption and peak demand, a process easily facilitated by the methods described herein.

Results from CERN experiment NA36 are reported. Cross sections for the production of singly strange particles in the S+Pb and p+Pb reactions have been measured in the rapidity range 1.25<y<3.5 and for p[sub t]>0.2 GeV. A significant difference in the rapidity distributions of the lambda particles originating from these reactions suggests a fundamental difference in the strangeness production mechanism.

The recently developed ability to synthesize materials from atomic precursors under controlled conditions on a nanometer size scale (below 100 nm) has the potential for revolutionizing materials science and engineering. Such nanostructured materials can now be synthesized with modulation dimensionalities form zero (clusters) to three (nanophase materials), each with their own particular advantages. These advantages stem from such diverse effects as for example quantum confinement elastic strain accommodation, and grain size limitations. The general principles of nanostructured materials are considered and the particular opportunities for producing bulk nanophase materials with engineered properties, via the synthesis of metal and ceramic atom clusters followed by their in-situ assembly under controlled conditions, are presented as an example.

This report discusses the involvement of the Pacific Northwest Laboratory in the development of vitrification technology for the treating of radioactive, chemical and mixed wastes since the 1960's.

The intense radiation, called beamstrahlung, during the collision of e{sup +}e{sup -} beams in a linear collider, is reviewed, with attention to the influence of beam-beam disruption on the beamstrahlung spectrum. We then discuss the various detector backgrounds induced by these hard beamstrahlung photons, as well as the Weiszacker-Williams photon, through various QED and QCD processes, namely the coherent and incoherent e{sup +}e{sup -} pair creation and the hadron production and minijet yields.

In this paper we present a brief summary of the CP violation physics to be undertaken at an asymmetric e[sup +]e[sup -] [Beta] factory.

In the fabrication of both 40 and 50 mm collider dipole superconducting magnets, surveys of the direction of the magnetic field along their length have been taken. This data besides being used for certifying compliance with the specifications for the finished magnet, yields interesting information on the straightness and rigidity of the coil placement between some stages in their manufacture and testing. A discussion on the measuring equipment and procedures is given. All of the 40 mm magnets that were built or cryostat at Fermilab have at least one of these surveys, and a summary of the data on them is presented. Most of the 50 mm magnets built and cold tested at Fermilab have been surveyed before and after insertion in the cryostat and before and after being cold tested. A summary of this data is also presented.

The statistical precision of a chord method for estimating dimension from a correlation integral is derived. The optimal chord length is determined, and a comparison is made to other estimators. The simple chord estimator is only 25% less precise than the optimal estimator which uses the full resolution and full range of the correlation integral. The analytic calculations are based on the hypothesis that all pairwise distances between the points in the embedding space are statistically independent. The adequacy of this approximation is assessed numerically, and a surprising result is observed in which dimension estimators can be anomalously precise for sets with reasonably uniform (nonfractal) distributions.

General Atomics (GA) has designed two legal weight truck (LWT) casks, the GA-4 and GA-9, to carry four pressurized-water-reactor (PWR) and nine boiling-water-reactor (BWR) fuel assemblies, respectively. GA plans to submit applications for certification to the US Nuclear Regulatory Commission (NRC) for the two casks in mid-1993. GA will include burnup credit analysis in the Safety Analysis Report for Packaging (SARP) for the GA-4 Cask. By including burnup credit in the criticality safety analysis for PWR fuels with initial enrichments above 3% U-235, public and occupation risks are reduced and cost savings are realized. The GA approach to burnup credit analysis incorporates the information produced in the US Department of Energy Burnup Credit Program. This paper describes the application of burnup credit to the criticality control design of the GA-4 Cask.

Hippoplotimus is a library package which manages and displays tables of data. It is written in ANSI C and has been tested on a large number of computer architectures. Hippo has a number of design features which make it unique. Data is saved in a binary machine-independent format using the industry-standard XDR. Hippo supports graphics on many devices, but does not use any high-level graphics package. Even though it written in ordinary C, the functions are all coded in an object-oriented'' manner. All the display functions have been optimized to allow for maximum interactivity.

The interaction (modelled by a LEPS potential) of a D[sub 2] molecule with an icosahedral Ni[sub 13] cluster is mapped and analyzed in the form of equipotential contour plots. The topological features of the map correlate with the energetic and dynamical characteristics of the dissociative adsorption of the molecule on the cluster, which were extracted from quasiclassical trajectory simulations. A modification of the LEPS potential used originally is introduced. It brings the calculated reactivity of the cluster into agreement with the experimental data.

This study utilizes a mechanistic model of lea photosynthesis to examine the potential quantitative significance of the interaction of rising atmospheric. Carbon dioxide concentration (C[sub a]) and temperature on leaf photosynthesis. Predictions are compared to experimental measurements in which plants have been grown either in elevated C[sub a] in the field for extended periods or from seed in controlled environments, to examine the interaction of low temperature with elevated C[sub a]. Three questions addressed were: To what extent will increase in C[sub a] modify the response of leaf photosynthetic CO[sub 2] uptake (A) to temperature; is the decrease in photosynthesis at sub-optimal temperatures predicted for plants grown at elevated C[sub a], realized in practice Is photoinhibition accentuated in plants grown in the field at elevated C[sub a] for long-periods.

A computational tool to be used in kinetic simulations of toroidal plasmas is being developed. The initial goal of the project is to develop an electrostatic gyrokinetic model for studying transport and stability problems in tokamaks. In this brief report, preliminary results from the early stages of this effort are presented.

Divertor biasing may provide a method for density and impurity control by enhancing the shielding efficiency of the scrape-off layer. The idea is to make the scrape-off plasma denser and thicker by heating it with a bias-driven current, and by inducing a radial E [times] B drift. If the bias is applied to flux surfaces at the outer edge of the usual scrape-off layer, a new layer of plasma can be added which is sustained by the bias-supplied power. A simple theoretical model will be presented which shows that there is a threshold condition which must be satisfied in order for the bias-heated plasma to be self-sustaining. The bias-sustained plasma must also be opaque enough to neutrals in order for it to be fueled by a gas puff, which means that it win serve as a shield to the core plasma against neutral impurities and hydrogen. Experiments performed on DIII-D have demonstrated both a modification of the central nickel impurity concentration and an increase in the ionization of hydrogen within the scrape-off layer due to biasing.

The phenomenon of surface melting in a Ni[sub 55] cluster is predicted from results of molecular dynamics simulations.

We describe a new design of the Infrared Free Electron Laser (IRFEL) for the proposed Chemical Dynamics Research Laboratory (CDRL) at LBL. The design and choice of parameters are dictated by the unique requirements of the CDRL scientific program. The accelerator system is based on the 500 MHz superconducting cavity technology to achieve a wavelength stability of 10[sup [minus]4].

Thirteen 16 m long, 50 mm aperture SSC dipole magnets, designed jointly by Fermilab, Brookhaven National Laboratory, Lawrence Berkeley Laboratory and the SSC Laboratory, have been built at Fermilab. The first nine magnets have been fully tested to date. The allowed harmonics are systematically shifted from zero by amounts larger than the specification. The unallowed harmonics, with the exception of the skew sextupole, are consistent with zero. The magnet-to-magnet RMS variation of all harmonics is much smaller than the specification.

A series of 1.5 meter long and 50 mm aperture model SSC collider dipole magnets have been successfully built and tested at Fermilab. Later models have been built to test several extensions to the Fermilab design and variations in the manufacturing parameters. Some of the variations tested included conductor insulation scheme, alternate materials for coil end parts and coil winding. The coils are instrumented with voltage taps for the purposes of quench localization and with strain gages to measure the stresses and deflections in the coil and magnets support structure. Data from the quench performance, coil stress, end force and harmonics are presented and compared with design expectations and correlated with changes in the magnet design and assembly methods.

Laminar and turbulent conical Bunsen type flames were used. The study compares results from normal gravity with the burner in an up-right orientation (+g), the burner inverted (-g), and in microgravity ([mu]g) by using the NASA Lewis drop tower facility. The primary diagnostic is a laser schlieren system and some LDA measurements were taken for the +g condition to measure the flow field. The +g laminar flame experiences a large amount of instabilities and results in an unsteady flame tip; cause is torroidal vortex rolling up between products and stagnate surrounding air. Comparison between LDA measurements in reactants and schlieren images shows that velocity fluctuation are induced at the same frequency as the roll up vortices are formed. This pumping of the reactant stream by the product/air interface instability in the +g case is also observed in the turbulent flames. In the -g arrangement the product/air interface is stable so there is no large pumping of the flame tip. At low flow rates the -g flames have flattened tips, but at higher flow rates they become conical in shape. When both flames. appear conical, the -g flames are longer for the same flow rate. In [mu]g the larger instabilities in …

We describe a code management and distribution system based on tools freely available for the UNIX systems. At the master site, version control is managed with CVS, which is a layer on top of RCS, and distribution is done via NFS mounted file systems. At remote sites, small modifications to CVS provide for interactive transactions with the CVS system at the master site such that remote developers are true peers in the code development process.

Quantitative X-ray and neutron diffraction measurements were made on nanocrystalline and coarse-grained samples of Pd and Cr. For both materials, Debye-Waller parameter comparisons over a temperature range of approximately 20-300 K indicate that the nanocrystalline materials have increased static displacements of atoms from their equilibrium sites compared to coarse-grained material. No grain-size-correlated differences in thermal vibrational amplitude, lattice parameter, or thermal expansion coefficients were observed in either material. In contrast to earlier results on nanocrystalline Pd, significantly more non-peak intensity is observed from a nanocrystalline Cr sample than from a coarse-grained Cr sample. Impurities may account for the increased background intensity from nanocrystalline Cr. These results indicate that there is no significant grain boundary excess volume in nanocrystalline Pd, and therefore the reduced density typically observed in nanocrystalline Pd samples must be due to porosity.