Classical relaxation of Br2 molecules in an argon heat bath
Classical relaxation of Br2 molecules in argon heat bath
Razner, R.↗
SEARCH · Search NASA
Results for “classical”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Classical path broadening functions for a Debye shielded interaction
Procedure to replace electron correlation effects with Debye shielded interaction including classical path broadening functions for Stark effects
Cooper, J.↗
Classical study of rotational excitation of a rigid rotor: Li+ plus H2
Classical trajectory study of rotationally inelastic scattering of hydrogen molecules by collisions with lithium ions
La Budde, R. A.↗
Molecular collisions. 16: Comparison of GPS with classical trajectory calculations of rotational inelasticity for the Ar-N2 system
Comparison of generalized phase shift treatment with classical trajectory calculations of rotational inelasticity cross sections of Ar-N2 scattering
Pattengill, M. D.↗
Classical fourth- and lower order Runge-Kutta formulas with stepsize control and their application to heat transfer problems
Classic fourth and lower order Runge-Kutta formulas with stepsize control, applying to heat transfer problems
Fehlberg, E.↗
Classical adiabatic perturbation theory
Classical Poincare-von Zeipel canonical perturbation theory extension to adiabatically perturbed systems with slow dependence on time or dynamic variables
Stern, D. P.↗
Part 1: Classical laser. Part 2: The effect of velocity changing collisions on the output of a gas laser
A classical model for laser action is discussed, in which an active medium consisting of anharmonic oscillators interacts with an electromagnetic field in a resonant cavity. Comparison with the case of a medium consisting of harmonic oscillators shows the significance of nonlinearities for producing self-sustained oscillations in the radiation field. A theoretical model is presented for the pressure dependence of the intensity of a gas laser, in which only velocity-changing collisions with foreign gas atoms are included. A collision model for hard sphere, repulsive interactions was derived. Collision theory was applied to a third-order expansion of the polarization in powers of the cavity electric field (weak signal theory).
Borenstein, M.↗
Unified classical path theories of pressure broadening.
Derivation of a unified classical path theory of pressure broadening, using only elementary concepts. It is shown that the theory of Smith, Cooper and Vidal (1969) is only correct at all frequencies to first order in the number density of perturbers.
Bottcher, C.↗
Redundancy of constraints in the classical and quantum theories of gravitation.
It is shown that in Dirac's version of the quantum theory of gravitation, the Hamiltonian constraints are greatly redundant. If the Hamiltonian constraint condition is satisfied at one point on the underlying, closed three-dimensional manifold, then it is automatically satisfied at every point, provided only that the momentum constraints are everywhere satisfied. This permits one to replace the usual infinity of Hamiltonian constraints by a single condition which may be taken in the form of an integral over the manifold. Analogous theorems are given for the classical Einstein Hamilton-Jacobi equations.
Moncrief, V.↗
Classical scattering calculations for diatomic molecules: A general procedure and application to the microwave spectrum O2
Many properties of gaseous systems such as electromagnetic absorption and emission, sound dispersion and absorption, may be elucidated if the nature of collisions between the particles in the system is understood. A procedure for the calculation of the classical trajectories of two interacting diatomic molecules is described. The dynamics of the collision will be assumed to be that of two rigid rotors moving in a specified potential. The actual outcome of a representative sample of many trajectories at 298K was computed, and the use of these values at any temperature for calculations of various molecular properties will be described. Calculations performed for the O2 microwave spectrum are given to demonstrate the use of the procedure described.
Mingelgrin, U.↗
On the computation of the generalized inverse by classical minimization.
An alternative method for deriving the generalized inverse of an arbitrary rectangular matrix with real or complex coefficients is described. The method applies a classical minimization procedure without iteration processes and is readily applicable in digital computer programming.
Voith, R. P.↗
Non-classical adhesive-bonded joints in practical aerospace construction
Solutions are derived for adhesive-bonded joints of non-classical geometries. Particular attention is given to bonded doublers and to selective reinforcement by unidirectional composites. Non-dimensionalized charts are presented for the efficiency limit imposed on the skin as the result of the eccentricity in the load path through the doubler. It is desirable to employ a relativly large doubler to minimize the effective eccentricity in the load path. The transfer stresses associated with selective reinforcement of metal structures by advanced composites are analyzed. Reinforcement of bolt holes in composites by bonded metal doublers is covered quantitatively. Also included is the adhesive joint analysis for shear flow in a multi-cell torque box, in which the bond on one angle becomes more critical sooner than those on the others, thereby restricting the strength to less than the total of each maximum strength when acting alone. Adhesive plasticity and adherend stiffness and thermal imbalances are included. A simple analysis/design technique of solution in terms of upper and lower bounds on an all-plastic adhesive analysis is introduced.
Hart-Smith, L. J.↗
Perturbation theory of structure in classical liquid mixtures: Application to metallic systems near phase separation
The partial structure factors of classical simple liquid mixtures near phase separation are dicussed. The theory is developed for particles interacting through pair potentials, and is thus appropriate both to insulating fluids, and also to metallic systems if these may be described by an effective ion-ion pair interaction. The motivation arose from consideration of metallic liquid mixtures, in which resistive anomalies have been observed near phase separation. A mean field theory correction appropriate to 3 pair potential for the effects of correlated motions in the reference fluid is studied. The work is cast in terms of functions which are closely related to the direct correlation functions of Ornstein and Zernike. The results are qualitatively in accord with physical expectations. Quantitative agreement with experiment seems to turn on the selection of the hard core reference potential in terms of the metallic effective pair potential. It is suggested that the present effective pair potentials are perhaps not properly used to calculate the metallic structure factors at long wavelength.
Henderson, R. L.↗
Transient cooling of solid bodies of classical form by radiation
An approximate analytic method is presented for analysis of the unsteady process of radiative cooling of solid bodies of classical form. The nonlinear heat transfer problem is solved by the cascade linearization technique with use of the iteration method. Comparison of the results obtained even in the first approximation with the available numerical solutions indicates adequate engineering accuracy of the proposed technique.
Novikov, V. S.↗
Programs for computing abscissas and weights for classical and nonclassical Gaussian quadrature formulas
Computer programs for computing Gaussian quadrature abscissas and weights are described. For the classical case the programs use Laguerre iteration to compute abscissas as zeros of orthogonal polynomials. The polynomials are evaluated from known recursion coefficients. The nonclassical case is handled similarly except that the recursion coefficients are computed by numerical integration. A sample problem, with input and output, is presented to illustrate the use of the programs. It computes the quadrature abscissas and weights associated with the weight function over the interval (0,1) for quadrature orders from 16 to 96 in increments of 8.
Desmarais, R. N.↗
Ultraviolet observations of classical Cepheids by OAO-2
OAO-2 observations of eight bright classical Cepheids in the wavelength region 1910 A to 4250 A are presented. The data for RT Aurigae, alpha Ursa Minoris, delta Cephei, and gamma Ophiuchi show excellent agreement with ground based photometry in the wavelength region of overlap and are consistent with a simple extrapolation of light curve properties from the visible region. However, in the ultraviolet, the light curve of beta Doradus shows two small flux bumps, at phases of 0.75 and 0.85, in addition to the well known bump at phase 0.0. All three bumps should probably be associated with the arrival of shocks at the stellar surface.
Hutchinson, J. L.↗
Classical trajectory study of internal energy distributions in unimolecular processes
Energy flow in a molecular system such as CD3Cl or CD3H representing a chemical activation experiment is studied by the method of classical trajectories. A correlation function method is used to obtain energy distributions before and after the breakup of the activated molecule. The energy distribution in the final product is found to be randomly distributed for a surface with no exit channel barrier or strong intermode couplings. Nonrandom energy distributions result when these special forces are present. Product channel barriers result in an excess of translational energy and exit channel intermode couplings result in nonrandom vibrational distributions.
Mcdonald, J. D.↗
Monte Carlo simulation of the classical two-dimensional one component plasma
Monte Carlo simulation, lattice dynamics in the harmonic approximation, and solution of the hypernetted chain equation were used to study the classical two-dimensional one component plasma. The system consists of a single species of charged particles immersed in a uniform neutralizing background. The particles interact via a l/r potential, where r is the two dimensional separation. Equations of state were calculated for both the liquid and solid phases. Results of calculation of the thermodynamic functions and one and two particle correlation functions are presented.
Gann, R. C.↗