Search results for "rotation"
showing 10 items of 935 documents
Rotational Three-Body Resonances: A New Adiabatic Approach
2001
In the standard adiabatic approach the motion of the fast, light particle (electron) is treated so as to produce an effective potential that governs the motion of the heavy particles (nuclei). The rotational degrees of freedom are then taken into account by adding the centrifugal J(J + 1)-term to the channel potentials and introducing rotational (Coriolis) couplings into conventional close-coupling calculations. Of course, a perturbative treatment of the rotational motion is justified only provided the rotational energy is sufficiently small. If, however, the rotation is as energetic as the motion of the fast particle, both motions should be treated on the same footing in order to produce s…
Cluster rotational bands in 11B
2016
Differential cross-sections of 11B+α inelastic scattering at E(α) = 65 MeV leading to most of the known 11B states at excitation energies up to 14 MeV were measured [1]. The data analysis was done using Modified diffraction model (MDM) [2] allowing determining radii of excited states. Radii of the states with excitation energies less than ∼ 7 MeV coincide with the radius of the ground state with an accuracy not less than 0.1 - 0.15 fm. This result is consistent with traditional view on shell structure of low-lying states in 11B. Most of the observed high-energy excited states are distributed among four rotational bands. Moments of inertia of band states are close to the moment of inertia of…
Effect of a Steady Magnetic Field and Imposed Rotation of Vessel on Heat and Mass Transfer in Swirling Recirculating Flows
1999
A simplified theoretical model for the solidification interface shape prediction is introduced and tested. We linearised a coupled hydrodynamic-solidification problem about the state with a flat interface. In such a way we split the problem into a hydrodynamic part with a flat solid-liquid front and a solidification part with a calculated heat flux from the liquid phase. The method allows obvious conclusions on optimum heat conditions near the solidification interface providing its flatness and maximum pulling velocity at the same time. Comparison to the results by FLUENT package showed that the method provides a reasonable accuracy even for a noticeably deformed interface shape. Another pa…
Polarizability and optical rotation calculated from the approximate coupled cluster singles and doubles CC2 linear response theory using cholesky dec…
2004
A new implementation of the approximate coupled cluster singles and doubles CC2 linear response model using Cholesky decomposition of the two-electron integrals is presented. Significantly reducing storage demands and computational effort without sacrificing accuracy compared to the conventional model, the algorithm is well suited for large-scale applications. Extensive basis set convergence studies are presented for the static and frequency-dependent electric dipole polarizability of benzene and C60, and for the optical rotation of CNOFH2 and (−)-trans-cyclooctene (TCO). The origin-dependence of the optical rotation is calculated and shown to persist for CC2 even at basis set convergence. …
Spatially variable rate herbicide application on durum wheat in Sicily
2004
Using the conventional farming system, durum wheat requires high rates of herbicide spraying. Herbicide residues can cause pollution of soil and ground water and, therefore, of the entire environment. In order to minimise the environmental impact of herbicides, a home made system for spatially variable rate crop input application was designed, developed and set up by the Department of Engineering and Technologies in Agriculture and Forestry (I.T.A.F.). This system consists of a DGPS, a portable computer, a specifically developed software and a device for applying rates proportionally related to the machine forward speed (DPA). Tests of spatially variable rate herbicide application were carr…
Relaxation of self-entangled many-arm star polymers
1989
We present a description of the relaxation of star polymers based on the conformational scaling properties predicted by Daoud and Cotton and confirmed in our recent simulations. We identify three typical relaxation mechanisms. The first describes elastic deformation of the overall shape. Its relaxation time is nearly independent off. A second type of relaxation occurs via rotational diffusion. We predict that the relaxation time should scale with Nwlfz-v where Y is the correlation length exponent. A third relaxation process is the disentanglement of two or more arms. Here the longest relaxation time should increase exponentially with f llz. We measure various relaxation processes by molecul…
Vibrational and rotational collisional relaxation in CO2–Ar and CO2–He mixtures studied by stimulated Raman-infrared double resonance
1999
0021-9606; The collisional relaxation among vibrational levels of the Fermi dyad of CO2 mixed with Ar and He (10% CO2, 90% rare gas) has been studied at room temperature with a double resonance experiment. Stimulated Raman effect from the ground state achieved the pumping process with a Nd:YAG laser and a pulse amplified dye laser. After pumping the v(1) or 2v(2)(Sigma(+)g) level, a cw CO2 laser was used to probe either the depopulation rates of the pumped levels (vibrationally or rotationally resolved) or the energy transfer rates to neighboring states. The vibrational energy relaxation has been studied from experimental depopulation of v(1) and population of 2v(2) levels through a five-le…
Rovibrational structure of the Ar–CO complex based on a novel three-dimensional ab initio potential
2002
The first three-dimensional ab initio intermolecular potential energy surface of the Ar–CO van der Waals complex is calculated using the coupled cluster singles and doubles including connected triples model and the augmented correlation-consistent polarized valence quadruple zeta (aug-cc-pVQZ) basis set extended with a (3s3p2d1f1g) set of midbond functions. The three-dimensional surface is averaged over the three lowest vibrational states of CO. Rovibrational energies are calculated up to 50 cm−1 above the ground state, thus enabling comprehensive comparison between theory and available experimental data as well as providing detailed guidance for future spectroscopic investigations of highe…
Study of the benzene⋅N2 intermolecular potential-energy surface
2003
The intermolecular potential-energy surface pertaining to the interaction between benzene and N2 is investigated theoretically and experimentally. Accurate intermolecular interaction energies are evaluated for the benzene–N2 van der Waals complex using the coupled cluster singles and doubles including connected triples [CCSD(T)] method and the aug-cc-pVDZ basis set extended with a set of 3s3p2d1f1g midbond functions. After fitting the energies to an analytic function, the intermolecular Schrödinger equation is solved to yield energies, rotational constants, and Raman-scattering coefficients for the lowest intermolecular levels of several benzene–N2 isotopomers. Experimentally, intermolecula…
Computational and experimental investigation of intermolecular states and forces in the benzene-helium van der Waals complex
2003
A study of the intermolecular potential-energy surface (IPS) and the intermolecular states of the perprotonated and perdeuterated benzene–He complex is reported. From a fit to ab initio data computed within the coupled cluster singles and doubles including connected triples model for 280 interaction geometries, an analytic IPS including two- to four-body atom–atom terms is obtained. This IPS, and two other Lennard-Jones atom–atom surfaces from the literature, are each employed in dynamically exact (within the rigid-monomer approximation) calculations of J = 0 intermolecular states of the isotopomers. Rotational constants and Raman-scattering coefficients for intermolecular vibrational trans…