Article describes how continuum solvation models are becoming increasingly relevant in condensed matter simulations, allowing to characterize materials interfaces in the presence of wet electrified environments at a reduced computational cost with respect to all atomistic simulations. However, some challenges with the implementation of these models in plane-wave simulation packages still persists, and to address these challenges, the authors present the implementation of a double-cell formalism, in which the simulation cell used for the continuum environment is uncoupled from the one used for the electronic-structure simulation of the quantum-mechanical system.

This article determines the equilibrium solubility of benzoic acid in water and ethanol, as well as in nine {ethanol (1) + water (2)} mixtures from T = (293.15 to 323.15) K. The thermodynamic results presented could be useful in optimizing different physical and chemical processes involving benzoic acid in mixed aqueous-ethanol media.

This article is a commentary exploring the disciplines of Western medicine and Traditional Chinese Medicine's philosophical methods to fight COVID-19 to understand their philosophical theories that could achieve the maximum benefits for treatment of COVID-19 and other diseases.

This article proposes a plasma enclosed by an Artificially Structured Boundary (ASB) as an alternative to existing ion source assemblies. In accelerator applications, many ion sources can have a limited lifetime or frequent service intervals due to sputtering and eventual degradation of the ion source assembly. Ions are accelerated towards the exit canal of positive ion sources, whereas, due to the biasing scheme, electrons or negative ions are accelerated towards the back of the ion source assembly.

This article presents a configuration of magnetic fields using properties of cylindrically symmetric permanent magnets as a candidate to produce a high purity charged particle source or trap. Cylindrically symmetric hollow permanent magnets produce magnetic field point cusps on the axis of symmetry. A magnetic field point cusp reflects all particles that lie outside a narrow region of phase space, a region dependent on particle kinetic energies and on the magnetic field intensity.

This article is a commentary on "A role for the medial temporal lobe in feedback-driven learning: evidence from amnesia" by Foerde, K., Race, E., Verfaellie, M.,and Shohamy, D. (2013). It covers the idea that environmental feedback plays an important role with respect to both basal ganglia and hippocampus based learning. Evidence that both the hippocampus and the striatum are involved in reinforcement learning is given. This article suggests that future research use a more precise measurement of the two structures’ sensitivities to delay. The general picture suggests that the basal ganglia and the hippocampus share overlapping sensitivity to reinforcement signals, although at a different timescale.

Polarized neutron reflection was used to determine the magnetic structure of two different antiferromagnetically coupled multilayer systems, Fe/Gd and Fe/Cr. In Fe/Gd, the Fe and Gd moments are coupled antiparallel at the interface. At low temperatures a surface induced magnetic phase transition was found. In Fe/Cr, annealing at temperatures of up to 425{degrees}C, resulted in the degrading of antiferromagnetic coupling between Fe layers and in the formation of ferromagnetically coupled regions.

A number of high-level radioactive waste (HLW) safety issues have been identified at the Hanford Site in southeastern Washington State. Resolution of these issues is one of the Highest Priorities of the US Department of Energy. The most urgent issues are the potential for explosions in certain tanks (due to periodic venting of large quantities of flammable gases, or the presence of substantial quantities of ferrocyanide and/or organic compounds in combination with nitrates-nitrites). Other safety issues have been identified as well, such as the requirement for periodic water additions to one tank to control its temperature and the release of noxious vapors from a number of tanks. Substantial progress has been made toward safety issue resolution. Potential mechanisms have been identified for the generation, retention and periodic venting of flammable gas mixtures; potential methods for controlling the periodic release behavior have been identified and in-tank testing will be initiated in 1992. Research is being conducted to determine the initiation temperatures, energetics, reaction sequences and effects of catalysts and initiators on ferrocyanide-nitrate/nitrite reactions; waste characterization on a tank-by-tank basis will be required to identify whether ferrocyanide-containing wastes are safe to store as-is or will require further treatment to eliminate safety concerns. …

Bis(2-ethylhexyl)phosphoric acid (HDEHP) may be purified by absorption on a macroreticular, strong base anion exchange resin. Properties of ion exchange purified HDEHP are in excellent agreement with literature values.

The applications for SU(4) breaking for new particles considered are an expression of the vector and axial vector weak charges of charmed hadrons and a relativistic mass formula for vector mesons. Wave functions defined in momentum space are considered. Quantum numbers of various meson resonances are found. (JFP)

GAPCON-3 provides an integrated thermal and mechanical analysis of a reactor fuel pin in terms of its path-dependent power history. It is designed to handle the axial and radial variations in power, temperature, and fuel cladding mechanical interaction, normally encountered in LWR fuel. It provides detailed information regarding temperatures, stresses, and strains depending upon the mesh size selected and the needs of the user. The code uses a finite element formulation for the mechanical analysis and includes the effects of creep, plasticity, and anisotropy. The steady state thermal calculations are based upon the method of weighted residuals (MWR) and use a finite difference formulation for treating the transient thermal dependence. The fuel behavior models incorporate relocation, swelling, and densification as well as power history-dependent local fission gas release. The code is structured to operate efficiently and to allow its use in both parametric as well as detailed analysis applications. A typical problem on a CDC-6600 computer will require 8 to 10 seconds per time step for solution.

Multiquantum dissociation of polyatomics using intense CO/sub 2/ lasers resulting in isotopic enrichment has been demonstrated for several molecules. In this presentation, the possibility of selective dissociation of NH/sub 3/ and NH/sub 2/D by high power laser radiation at 10 ..mu..m will be considered. Relevant work performed at the Lawrence Livermore Laboratory and elsewhere will be summarized. In this review, attention will be given to four distinct mechanisms that can play varying degrees of importance in such investigations. Discussion will deal with the usefulness of two-resonant-frequency molecular excitation, the role of buffer gases, and the need to monitor the yields into the ground and excited electronic states of the dissociated fragments.

New technology has permitted significant performance improvements of established instrumentation techniques including beam position and profile monitoring. Fundamentally new profile monitor strategies are required for the next generation of accelerators, especially linear colliders (LC). Beams in these machines may be three orders of magnitude smaller than typical beams in present colliders. In this paper we review both the present performance levels achieved by conventional systems and present some new ideas for future colliders.

Progress made in developing a ..pi..NN model for describing all NN and ..pi..d reactions up to intermediate energy regions is reported. An accurate ..pi..NN model is the starting point of developing a microscopic description of nuclear phenomena up to the energy region where pion production can occur. The model can be used to carry out many-nucleon calculations, such as the calculations of pion absorption and electroproduction of ..delta.. on nuclei. It reduces to existing nuclear theory in the low energy region. 5 refs., 6 figs.

In aquifer thermal energy storage (ATES) systems, wells provide the interface between the energy storage and use. Efficient operational wells are, therefore, essential for the system to run at maximum (design) efficiency. Adequate test drilling to accurately predict aquifer properties is essential in the design phase; proper construction and development are crucial; and proper monitoring of performance is necessary to identify the early stages of clogging and to evaluate the adequacy of well rehabilitation. Problems related to hydrology, well, and aquifer properties include: loss of permeability resulting from gas exsolution, chemical precipitation, and dispersion and movement of fine-grained particles; loss of recoverable heat caused by excessive regional ground-water gradient, hydrodynamic mixing of injected and native ground water, buoyancy flow and heat conduction through the cap and base of the storage zone; leakage up along the well casing; and fracturing'' of a shallow upper aquiclude as a result of an injection pressure greater than the hydrostatic pressure on the aquiclude. The predominant geochemical problems encountered are precipitation of carbonates in some areas and iron plus manganese oxides in others. These precipitation problems can be anticipated, and thus avoided, via geochemical calculations. The likelihood of iron carbonate precipitation is less certain because …

A major mission of safeguards is to protect against the use of nuclear materials by adversaries to harm society. A hierarchical structure of safeguards responsibilities and activities to assist in this mission is defined. The structure begins with the definition of international or multi-national safeguards and continues through domestic, regional, and facility safeguards. The facility safeguards is decomposed into physical protection and material control responsibilities. In addition, in-transit safeguards systems are considered. An approach to the definition of performance measures for a set of Generic Adversary Action Sequence Segments (GAASS) is illustrated. These GAASS's begin outside facility boundaries and terminate at some adversary objective which could lead to eventual safeguards risks and societal harm. Societal harm is primarily the result of an adversary who is successful in the theft of special nuclear material or in the sabotage of vital systems which results in the release of material in situ. With the facility safeguards system, GAASS's are defined in terms of authorized and unauthorized adversary access to materials and components, acquisition of material, unauthorized removal of material, and the compromise of vital components. Each GAASS defines a set of ''paths'' (ordered set of physical protection components) and each component provides one …

This review of laser implosion research contains discussions on the efficiency of light absorption, processes of absorption, and the energy spectra of heated electrons. Diagrams are given showing the various processes and stages of a laser imploded target. Some calculational results using the LASNEX code are described. (MOW)

For the next generation of high performance, high average luminosity colliders, the factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis.

The Office of Waste Isolation of Union Carbide Corporation-Nuclear Division has been charged by the U. S. Energy Research and Development Administration with the responsibility to provide deep, land-based repositories in geologic formations for nuclear waste from the commercial fuel cycle. Design and construction of waste repositories require information relative to the behavior of rock under high-temperature and -pressure conditions for long periods of time. Experience has shown that although laboratory data characterizing rock properties are both necessary and useful for preliminary design studies, the behavior of the rock mass ultimately must be determined by in situ tests, preferably carried out at about the same depth and in the same formation horizon as would be used for the waste repository. This paper describes types of relevant in-situ tests.

The design of a 50 mm bore superconducting Nb[sub 3]Sn dipole with a short sample field of 13 T at 4.3 K and a current of 5500 A/turn is presented. The magnet is composed by two double pancake layers. The inner cable has 37 strands with a strand diameter of 0.75 mm and a Cu/Sc ratio of 0.4; the outer cable has 47 strands with a diameter of 0.48 mm and a Cu/Sc ratio of 1.15. In order to obtain a high transfer function and low saturation effects on the multipoles, the stainless steel collar is elliptical and the iron yoke is close-in.'' The thin collar itself provides only a minimum prestress and the full prestress of 100 MPa is given by a 25 mm welded stainless steel shell or by winding a wire around the yoke. Aluminum spacers are used as assembly tools and as a means to control the gap size in the vertically split iron yoke. This paper presents the magnetic design and the calculated stress and strain distribution in structure and coils. A 1 m model called D20 is to be built and tested at LBL.

High brightness beams with sub-micron dimensions are needed to produce a high luminosity for electron-positron collisions in the Next Linear Collider (NLC). To generate these small beam sizes, a large number of issues dealing with intense beams have to be resolved. Over the past few years many have been successfully addressed but most need experimental verification. Some of these issues are beam dynamics, emittance control, instrumentation, collimation, and beam-beam interactions. Recently, the Stanford Linear Collider (SLC) has proven the viability of linear collider technology and is an excellent test facility for future linear collider studies.

The design of high-[Tc] superconducting bolometers for use in a far infrared imaging array from wavelengths 30--100[mu]m is discussed. Measurements of the voltage noise in thin films of YBa[sub 2]CU[sub 3]O[sub 7-[var sigma]] on yttria-stabilized zirconia buffer layers on silicon substrates are used to make performance estimates. Useful opportunities exist for imaging and spectroscopy with bolometer arrays made on micro-machined silicon membranes. A circuit on each pixel which performs some signal integration can improve the sensitivity of large two-dimensional arrays of bolometers which use multiplexed readout amplifiers.

Intermediate level waste solution generated at ORNL is periodically mixed with a cement base blend of dry solids and injected into an impermeable shale formation at an approximate depth of 800 ft. Shortly after the injection the grout mix sets, permanently fixing the radionuclides in the shale formation. A series of three injections of intermediate level waste solution was made in 1975. A total of 190,000 gal of waste solution containing 86,700 Ci of radionuclides was injected. This report is an account of this injection series-- preparations, injections, results, and conclusions. A summary of the volumes and activities that were injected is given.

The laser system requirements for isotope enrichment are presented in the context of an atomic uranium vapor process. Coherently pumped dye lasers using as the pump laser either the frequency doubled Nd:YAG or copper vapor are seen to be quite promising for meeting the near term requirements of a laser isotope separation (LIS) process. The utility of electrical discharge excitation of the rare gas halogens in an LIS context is discussed.