Spin wave excitations were measured in the ferromagnetic phase of Nd1/2Sr1/2MnO3 by neutron scattering. This compound is located in proximity to the A-type antiferromagnetic state, and it shows a clear anisotropy and anomalous softening of the spin wave excitations. The softening in the ferromagnetic phase is induced by the orbital ordering.

An anthracene oil-based pitch, supplied by Industrial Química del Nalón, S.A was used as carbon matrix precursor (softening point of 112oC; elemental analysis: C: 93.6 %, H: 4.4 %, N, 1.0 %, S, 0.5% and O, 0.5%). The iron oxide nanoparticles were obtained following different procedures: (i) toluene reflux of Fe(CO)5 with Pluronic P127 in the presence of H2 [1]; (ii) treatment of a mixture of Fe...

A damage-plasticity constitutive model for the description of fracture in plain concrete is presented. Two approaches, the local model comprising the adjustment of the softening modulus and the nonlocal model based on spatial averaging of history variables, are applied to the analysis of a concrete bar subjected to uniaxial tension and to a three-point bending test. The influence of mesh size a...

An analytical theory of the optical transitions of a molecule bound at the surface of a He droplet is developed for the case of a strong softening of the excited-state nearest neighbor dynamics. The optical bandwidth is found to be determined by the zero-point kinetic energy released at the transition. The theory is applied to the triplet-triplet optical transition in Na2 molecule, for which an...

We study by extensive Monte Carlo simulations the effect of random bond dilution on the phase transition of the three-dimensional four-state Potts model that is known to exhibit a strong first-order transition in the pure case. The phase diagram in the dilution-temperature plane is determined from the peaks of the susceptibility for sufficiently large system sizes. In the strongly disordered re...

A novel Brönsted-Lewis acidic heteropoly organic-inorganic salt has been prepared via the replacement of protons in neat phosphotungstic acid with both organic and metal cations. This hybrid catalyst, Sm0.33[TEAPS]2PW12O40, exhibited satisfactory performance in the dimerization of rosin to prepare polymerized rosin Under optimum conditions (15.0 g rosin and 5.0 g Sm0.33[TEAPS]2PW12O40 catalyst ...

In this work, the results of studies on the evaluation of colloidal structure of coal-tar pitch compositions with selected waste polymers by fluorescence microscope. For pitch-polymer compositions containing 10-50 wt% waste polymer, softening point, coking value and content of components insoluble in toluene and quinoline were carried out. The results indicate that pitch-polymer compositions ca...

Several petroleum pitches have been prepared by thermal treatment of various petroleum-derived residues such as clarified oil, aromatic extract and pyrolysis tars. These pitches were characterized physico-chemically (softening point, coking value, QI, & TI) and instrumentally (NMR) and compared. Attempts have been made to correlate physicochemical properties of petroleum residues and pitches wi...

We report on a Monte Carlo study of the three-dimensional bond-diluted 4-state Potts model which, in the pure case, undergoes a strong first-order phase transition. Subject to quenched, random disorder one expects a softening to a continuous transition from a certain disorder strength on. Employing a combination of cluster algorithms, multicanonical methods and reweighting techniques, we obtain...