Search results for "equilibrium"

Conformational mobility of thianthrene-5-oxide.

2005

[reaction: see text] Data on the apparent dipole moment of thianthrene-5-oxide (1) and (1)H NMR spectra in different solvents support the conformational mobility of 1, which flaps between two limit boat conformations with the sulfinyl group in pseudoequatorial and pseudoaxial positions, respectively. The conformational equilibrium of 1 occurs too fast for the (1)H NMR (500 MHz) time-scale even at -130 degrees C, and the equilibrium constant has not been determined. The apparent dipole moments of 1 in n-hexane and 1,4-dioxane and the (1)H NMR spectra of 1 and the model compounds cis- and trans-thianthrene-5,10-dioxides (2) and thianthrene (5) in different solvents and at various temperatures…

On damping characteristics of frictional hysteresis in pre-sliding range

2016

Frictional hysteresis at relative motion in the pre-sliding range is considered. This effect is characterized by an elasto-plastic interaction, and that on the micro-scale, between two rubbing surfaces in contact that gives rise to nonlinear friction force. The pre-sliding friction force yields hysteresis in displacement. In this study, the damping characteristics of frictional hysteresis are analyzed. It is worth noting that we exclude the viscous damping mechanisms and focus on the pure hysteresis damping to be accounted in the friction modeling. The general properties of pre-sliding friction hysteresis are demonstrated and then compared with the limit case of discontinuous Coulomb fricti…

Equilibrium and nonequilibrium many-body perturbation theory: a unified framework based on the Martin-Schwinger hierarchy

2013

We present a unified framework for equilibrium and nonequilibrium many-body perturbation theory. The most general nonequilibrium many-body theory valid for general initial states is based on a time-contour originally introduced by Konstantinov and Perel'. The various other well-known formalisms of Keldysh, Matsubara and the zero-temperature formalism are then derived as special cases that arise under different assumptions. We further present a single simple proof of Wick's theorem that is at the same time valid in all these flavors of many-body theory. It arises simply as a solution of the equations of the Martin-Schwinger hierarchy for the noninteracting many-particle Green's function with…

The $^{144}$Ce source for SOX

2015

International audience; The SOX (Short distance neutrino Oscillations with BoreXino) project aims at testing the light sterile neutrino hypothesis. To do so, two artificials sources of antineutrinos and neutrinos respectively will be consecutively deployed at the Laboratori Nazionali del Gran Sasso (LNGS) in close vicinity to Borexino, a large liquid scintillator detector. This document reports on the source production and transportation. The source should exhibit a long lifetime and a high decay energy, a requirement fullfilled by the (144)Ce-(144)Pr pair at secular equilibrium. It will be produced at FSUE “Mayak” PA using spent nuclear fuel. It will then be shielded and packed according t…

Elimination of spourious kinematic modes in hybrid equilibrium element

2011

It is widely recognized that displacement based elements produce solution with poor stress fields, which do not satisfy equilibrium equations. In several fields of computational mechanics, such as cohesive crack propagation and cohesive delamination, stress fields drive all the nonlinear phenomena and very fine meshes have to be employed in order to avoid numerical instabilities. Inter-element equilibrium condition is generally not satisfied and the stress field can abruptly change between adjacent elements, producing numerical instabilities in non linear analysis. Finite element formulation based on stress fields satisfying locally equilibrium condition are known in literature since 1964 b…

Molecular dynamics simulations of elementary chemical processes in liquid water using combined density functional and molecular mechanics potentials.…

1997

The first molecular dynamics (MD) simulation of a chemical process in solution with an ab initio description of the reactant species and a classical representation of the solvent is presented. We study the dynamics of proton (deuterium) transfer in strongly hydrogen-bonded systems characterized by an energy surface presenting a double well separated by a low activation barrier. We have chosen the hydroxyl-water complex in liquid water to analyze the coupling between the reactive system and the environment. The proton is transferred from one well to the other with a frequency close to 1 ps−1 which is comparable to the low-frequency band associated to hindered translations, diffusional transl…

Boundary Behavior of Harmonic Functions on Gromov Hyperbolic Manifolds

2013

Strong thermal nonequilibrium in hypersonic CO and CH4 probed by CRDS

2015

A new experimental setup coupling a High Enthalpy Source (HES) reaching 2000 K to a cw-cavity ring-down spectrometer has been developed to investigate rotationally cold hot bands of polyatomic molecules in the [1.5, 1.7] μm region. The rotational and vibrational molecular degrees of freedom are strongly decoupled in the hypersonic expansion produced by the HES and probed by cavity ring-down spectroscopy. Carbon monoxide has been used as a first test molecule to validate the experimental approach. Its expansion in argon led to rotational and vibrational temperatures of 6.7 ± 0.8 K and 2006 ± 476 K, respectively. The tetradecad polyad of methane (1.67 μm) was investigated under similar condit…

TAP-polymorphisms in juvenile onset psoriasis and psoriatic arthritis.

1996

Abstract Juvenile onset psoriasis is strongly associated with the HLA-class I genes Cw6 and B57 whereas patients with psoriatic arthritis show an increased frequency of HLA-B27. It is unclear whether additional major histocompatibility genes also increase disease susceptibility. The TAP genes (transporter associated with antigen processing) encode two membrane-spanning proteins that translocate antigenic peptides from the cytoplasm into the endoplasmic reticulum. Comparison of 60 patients with juvenile onset psoriasis, 63 psoriatic arthritis patients, and 101 caucasoid controls revealed an increase of the TAP1 ∗ 0101 allele in the psoriasis group, that could not be explained by linkage to o…

L'ouverture de la Chine et ses impacts sur l'économie chinoise

2012

In the early 1980s, Chinese government has adopted an opening up policy in order to attract capital, skills and modern advanced technology that are necessary for the economic development of China. Indeed, this policy has already borne fruit. China, that was almost self-sufficient until the 1980s, has now become the largest exporter and the second largest recipient of foreign direct investment in the world. Until now, most of the research on the economic opening up policy of China, however, has concentrated on the demonstration of the positive effects of exports and FDI inflows on the domestic economy of China. In this thesis, based on the analysis of economics of production, we study the re…