Cluster expansion approach to the effective potential in Φ 2+1 4 -theory

We apply a truncated set of dynamical equations of motion for connected equal-time Green functions up to the 4-point level to the investigation of spontaneous ground state symmetry breaking in Φ ₂₊₁ ⁴ quantum field theory. Within our momentum space discretization we obtain a second order phase transition as soon as the connected 3-point function is included. However, an additional inclusion of the connected 4-point function still shows a significant influence on the shape of the effective potential and the critical coupling.     

First principles investigation of chromium carbide, CrC

We have investigated the electronic structure of 14 states of the experimentally unknown diatomic molecule chromium carbide, CrC, using standard multireference configuration interaction methods and high quality basis sets. We report potential curves, binding energies, and a number of spectroscopic parameters. The ground state of CrC, X 3Sigma-, displays triple-bond character with a binding energy of D(e)=89 kcal/mol and an internuclear separation of r(e)=1.63 A. The first excited state (1 5Sigma-) lies 9.2 kcal/mol higher. All the states studied are fairly ionic, featuring an electron transfer of 0.3-0.5e- from the metal atom to the carbon atom.     

Ferrimagnetic ceramic adsorbents for cleanup of H2S from exhaust gases

Adsorbents that exhibit magnetic properties in addition to other required process-relevant characteristics open up new perspectives for the dry reduction and/or elimination of HES and other sulfur compounds from exhaust gases. These adsorbents eliminate the sulfur compounds from exhaust gases by virtue of their coatings and their magnetic property which makes it possible the use of magnetically assisted and stabilized fluidization in an externally applied magnetic field. In the present paper, the feasibility of the sorptive function of porous ceramic ferrimagnetic beads is ensured by sol-gel coating of zinc oxide without the formation of Zn-Fe-oxides and without considerable decrease of available pore volume. The results of material characterization by SEM, Auger electron spectroscopy, X-ray and mercury-porosity measurements and the loading capacity of a HES/N2 model gas are presented and discussed. The resulting HES loading of the functionalized adsorbent beads is more than 10 times larger than that of the starting material. @ 2007 Chinese Society of Particuolo~v and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V.     

Equilibrium and non-equilibrium hard thermal loop resummation in the real time formalism

We investigate the use of the hard thermal loop (HTL) resummation technique in non-equilibrium field theory. We use the Keldysh representation of the real time formalism (RTF). We derive the HTL photon self energy and the resummed photon propagator. We show that no pinch singularities appear in the non-equilibrium HTL effective propagator. We discuss a possible regularization mechanism for these singularities at higher orders. As an example of the application of the HTL resummation method within the RTF we discuss the damping rate of a hard electron. Received: 9 April 1998 / Published online: 21 September 1998     

H Magnetic resonance imaging of rigid polymeric solids

Implementation of the ¹H magnetic resonance single-point imaging technique has provided new opportunities for the direct imaging of rigid solids, particularly semicrystalline polymers with spin-spin relaxation times, T^*₂, of the order of 10 μs and greater. Potential applications of industrial relevance in the following areas are briefly discussed and illustrated: fabricated/processed parts, photochemical degradation, oxidation, and blend characterization.     

Scalar mesons and the search for the O + + glueball

The possibility that gluonic excitations of hadronic matter or of the QCD vacuum may exist is perhaps one of the most fascinating topics in hadron spectroscopy. Glueballs are predicted by many models; in particular, present-day lattice gauge calculations require their existence. All these models agree that the lightest glueball should have scalar quantum numbers and a mass around 1.6GeV, which corresponds to the mass region where the scalar -mesons are expected. Therefore, mixing effects can complicate the search for the glueball. Experiments indeed show an overpopulation of states, for which many different interpretations exist. This reflects the complexity of the situation. New data from various experiments on scalar states give hints toward an interpretation of the scalar states. But still many questions remain.Received: 30 September 2002, Published online: 22 October 2003PACS: 12.39.Mk Glueball and nonstandard multi-quark/gluon states - 12.38.-t Quantum chromodynamics - 14.70.Dj Gluons