Pion-pair formation and the pion dispersion relation in a hot pion gas

The possibility of pion--pair formation in a hot pion gas, based on the bosonic gap equation, is pointed out and discussed in detail. The critical temperature for condensation of pion pairs (Evans--Rashid transition) is determined as a function of the pion density. As for fermions, this phase transition is signaled by the appearance of a pole in the two--particle propagator. In bose systems there exists a second, lower critical temperature, associated with the appearance of the single--particle condensate. Between the two critical temperatures the pion dispersion relation changes from the usual quasiparticle dispersion to a Bogoliubov--like dispersion relation at low momenta. This generalizes the non-relativistic result for an attractive bose gas by Evans et al. Possible consequences for the inclusive pion spectra measured in heavy--ion collisions at ultra--relativistic energies are discussed.Comment: 16 pages revtex, 7 Postscript figure

Simultaneous determination of toxic compounds produced during fermentation of wine.

The objective of this study was to investigate the need to use of GC×GC to quantify toxic compounds (acetaldehyde, formaldehyde, ethyl carbamate and acrolein) produced during the fermentation of Syrah wine

Evaluation of toxic compounds produced during the elaboration of Syrah wines.

The objective of this study was to verify the occurrence of four toxic compounds (acetaldehyde, formaldehyde, ethyl carbamate and acrolein) in Syrah wines through the use of comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection

Influence of stage of ripeness and time of maceration of Syrah grapes on levels of toxic compounds in wines.

The aim of this study was to evaluate the influence of ripeness stage and time of maceration of Syrah grapes on the levels of six toxic compounds (formaldehyde, acetaldehyde, ethyl carbamate, furan, furfural and acrolein) formed during the vinification

Characterization of risk exposure to carbonyl and furan compounds through wine consumption.

The objective of this study was to: (i) quantify acetaldehyde, formaldehyde, ethyl carbamate, furan, furfural and acrolein in wine using headspace-solid phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometric detection (GC×GC/TOFMS) and (ii) characterize the risk of exposure to these toxic compounds through wine consumption

Influence of vineyard managements on aroma of Merlot wines.

The objective of this study is to evaluate the influence of vineyard managements on aroma of Campanha Gaúcha Merlot wines through quantitative descriptive analysis (QDA), gas chromatography ? olfactometry (GC - O) and comprehensive two - dimensional gas chromatography coupled to time-of -flight mass spectrometric detection (GC × GC/TOFMS)

Entropy production by resonance decays

We investigate entropy production for an expanding system of particles and resonances with isospin symmetry -- in our case pions and $\rho$ mesons -- within the framework of relativistic kinetic theory. A cascade code to simulate the kinetic equations is developed and results for entropy production and particle spectra are presented.Comment: 17 pages, 10 ps-figures included, only change: preprint number adde

Pion-Production in Heavy-Ion Collisions at SIS energies

We investigate the production of pions in heavy-ion collisions in the energy range of $1$ - $2$ GeV/A. The dynamics of the nucleus-nucleus collisions is described by a set of coupled transport equations of the Boltzmann-Uehling-Uhlenbeck type for baryons and mesons. Besides the $N(938)$ and the $\Delta(1232)$ we also take into account nucleon resonances up to masses of $1.9 GeV/c^2$ as well as $\pi$-, $\eta$- and $\rho$-mesons. We study in detail the influence of the higher baryonic resonances and the $2\pi$-production channels ($NN\to NN \pi\pi$) on the pion spectra in comparison to $\pi^-$ data from $Ar + KCl$ collisions at $1.8$ GeV/A and $\pi^0$-data for $Au+Au$ at 1.0 GeV/A. We, furthermore, present a detailed comparison of differential pion angular distributions with the BEVALAC data for Ar + KCl at 1.8 GeV/A. The general agreement obtained indicates that the overall reactions dynamics is well described by our novel transport approach.Comment: 31 pages, 18 figures (inlcuded), to appear in Z. Phys.

Characterization of volatile and sensory profile of Cabernet Sauvignon wines produced in six different vineyards of the Campanha Gaúcha region, Brazil.

XV Congresso Latino-Americano de Viticultura e Enologia E XIII Congresso Brasileiro de Viticultura e Enologia. Bento Gonçalves-RS, 3 a 7 de Novembro de 2015