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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Density Functional Theory Approach to Nuclear Fission
The Skyrme nuclear energy density functional theory (DFT) is used to model neutron-induced fission in actinides. This paper focuses on the numerical implementation of the theory. In particular, it reports recent advances in DFT code development on leadership class computers, and presents a detailed analysis of the numerical accuracy of DFT solvers for near-scission calculations.
IMPLEMENTATION OF OPTIMIZED ADAPTIVE CONTROL FUNCTIONS - A PROBLEM IN MULTIVARIATE FUNCTION APPROXIMATION
Multivariate function approximation forms the basis of adaptive control systems for space flight
Saturn i launch vehicle sa-8 and launch complex 37b functional systems description. volume vi- environmental conditioning systems functional description, index of finding numbers, and mechanical schematics
Saturn I /SA-8/ launch vehicle - environmental control systems, functional description, index of finding numbers, and schematics of launch complex
Saturn i launch vehicle sa-10 and launch complex 37b functional systems description. volume vii- launch pad accessories function- al description, index of finding numbers, and mechanical schematics
Saturn I /SA-10/ - launch pad accessories functional description, finding numbers, and schematics
Saturn i, launch vehicle sa-10 and launch complex 37b functional systems description. vol. vi- environmental conditioning systems, functional description, index of finding numbers, and mechanical schematics
Saturn I /SA-10/ launch vehicle and Launch Complex 37B functional systems description - environmental conditioning, index of finding numbers, and mechanical schematics
Saturn i launch vehicle sa-8 and launch complex 37b functional systems description. volume vii- launch pad accessories - functional description, index of finding numbers, and mechanical schematics
Saturn I /SA-8/ launch vehicle - launch pad accessories functional description, index of finding numbers, and mechanical schematics
Saturn i launch vehicle sa-10 and launch complex 37b functional systems description. volume i- rp-1 fuel system functional description, index of finding numbers, and mechanical schematics
Saturn launch vehicle and launch complex functional description - RP-1 fuel system, finding numbers, and schematics
Structure and function of E. coli ribosomes. IV - Isolation and characterization of functionally active ribosomal proteins.
E. coli ribosomes structure, molecular components, function and protein synthesis with artificial ribosome derivatives deficient in one component
Non-Maxwellian velocity distribution functions associated with steep temperature gradients in the solar transition region. Paper 1: Estimate of the electron velocity distribution functions
It was shown that, in the presence of the steep temperature gradients characteristic of EUV models of the solar transition region, the electron and proton velocity distribution functions are non-Maxwellian and are characterized by high energy tails. The magnitude of these tails are estimated for a model of the transition region and the heat flux is calculated at a maximum of 30 percent greater than predicted by collision-dominated theory.
A reference standard for bidirectional reflection distribution function and bidirectional transmission distribution function measurement
A Lambertian reference standard for uniformly scattering a beam of light is constructed of a plate having a planar surface with a layer of glue disposed on the surface. An evenly packed layer of monodisperse spheres is set in the layer, and when the standard is used for bi-directional (BRDF) measurements, the spheres are coated with a layer of highly relective substance, such as gold or silver. When the standard is used for bi-directional transmittance distribution function (BTDF) measurements, the spheres are of a transparent material and are provided with a roughened surface, as by acid etching. In this case, the layer of glue is an optical cement, and the plate is of glass, with the spheres, the layer, and the plate all possessing a similar refractive index.
The wave function and minimum uncertainty function of the bound quadratic Hamiltonian system
The bound quadratic Hamiltonian system is analyzed explicitly on the basis of quantum mechanics. We have derived the invariant quantity with an auxiliary equation as the classical equation of motion. With the use of this invariant it can be determined whether or not the system is bound. In bound system we have evaluated the exact eigenfunction and minimum uncertainty function through unitary transformation.
The Initial Mass function for Massive Stars in the Magellanic Clouds. III. Luminosity and Mass Functions for 14 OB Associations
This paper describes the use of UBV photometry of 14 associations in the Large and Small Magellanic Clouds to derive luminosity and mass functions for the most massive stars in the associations.
Method and apparatus for monitoring dynamic cardiovascular function using n-dimensional representatives of critical functions
A method, system, apparatus and device for the monitoring, diagnosis and evaluation of the state of a dynamic pulmonary system is disclosed. This method and system provides the processing means for receiving sensed and/or simulated data, converting such data into a displayable object format and displaying such objects in a manner such that the interrelationships between the respective variables can be correlated and identified by a user. This invention provides for the rapid cognitive grasp of the overall state of a pulmonary critical function with respect to a dynamic system.
Systems and Methods for Transfer Function Estimation Using Membership Functions
An apparatus, method, and computer program that can learn a linear or non-linear transfer function are disclosed. In one embodiment, for example, a computer-implemented method may include creating a plurality of combinations for at least one input, and calculating an output for the plurality of combinations. The method may also include calculating an error based on the calculated output.
Stabilization and Structure Calculations for Noncovalent Interactions in Extended Molecular Systems Based on Wave Function and Density Functional Theories
More than 20 years ago, we published in Chemical Reviews a paper entitled “Intermolecular Interactions between Medium-Sized Systems. Nonempirical and Empirical Calculations of Interaction Energy: Successes and Failures”. The situation in calculations of noncovalent interactions at that time can be best characterized by the question we posed at the very beginning of the review: “Can quantum chemistry describe vdW (van der Waals; today we call it noncovalent) interactions as successfully as covalent interactions?” Our answer then was “unambiguously yes”. We had good reason for an optimistic “yes” since we presented the first coupledcluster calculations including triple excitations for a (at that time) large complexsthe water dimer. We stressed the importance of the triple excitations for noncovalent interactions, and in the section called Prospects, we wrote that “significant progress is highly desirable with beyond-SCF methods, where new, more accurate and efficient procedures are developed”. In this respect we were right, and in the past 20 years, we have witnessed an enormous growth of interest in the fast and accurate calculation of intermolecular interactions. What is the reason for such an interest, or more generally, why are noncovalent interactions so relevant in modern research? Is it the mere existence of noncovalent complexes in the gas and liquid phases? Certainly not. The answer should be sought in the role that noncovalent interactions are playing in both bio- and nanostructures.
Metallic behavior and negative differential resistance properties of (InAs){sub n} (n = 2 − 4) molecule cluster junctions via a combined non–equilibrium Green's function and density functional theory study
In this present work, the geometric structures and electronic transport properties of (InAs){sub n} (n = 2, 3, 4) molecule cluster junctions are comparatively investigated using NEGF combined with DFT. Results indicate that all (InAs){sub n} molecule cluster junctions present metallic behavior at the low applied biases ([−2V, 2V]), while NDR appears at a certain high bias range. Our calculation shows that the current of (InAs){sub 4} molecule cluster–based junction is almost the largest at any bias. The mechanisms of the current–voltage characteristics of all the three molecule cluster junctions are proposed.
Phase space effects on fast ion distribution function modeling in tokamaks
Integrated simulations of tokamak discharges typically rely on classical physics to model energetic particle (EP) dynamics. However, there are numerous cases in which energetic particles can suffer additional transport that is not classical in nature. Examples include transport by applied 3D magnetic perturbations and, more notably, by plasma instabilities. Focusing on the effects of instabilities, ad-hoc models can empirically reproduce increased transport, but the choice of transport coefficients is usually somehow arbitrary. New approaches based on physics-based reduced models are being developed to address those issues in a simplified way, while retaining a more correct treatment of resonant wave-particle interactions. The kick model implemented in the tokamak transport code TRANSP is an example of such reduced models. It includes modifications of the EP distribution by instabilities in real and velocity space, retaining correlations between transport in energy and space typical of resonant EP transport. The relevance of EP phase space modifications by instabilities is first discussed in terms of predicted fast ion distribution. Results are compared with those from a simple, ad-hoc diffusive model. It is then shown that the phase-space resolved model can also provide additional insight into important issues such as internal consistency of the simulations and mode stability through the analysis of the power exchanged between energetic particles and the instabilities.