658 research outputs found

    Membrane processing of grape must for control of the alcohol content in fermented beverages

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    The great demand of beverages, both alcohol-free and with low alcohol content, is a great challenge for the production of beverages with controlled alcohol content through the use of sustainable enological practices. The present work addresses this challenge with the processing of grape must by reverse osmosis (RO) for must reconstitution with different sugar contents prior to the alcoholic fermentation. The original must came from grapes grown in Quinta do Quinto, in Santarém, collected after destemming and mechanic crushing, and preserved in a refrigerated chamber at -1.6 °C until processing by RO. The RO processing was carried out in Escola Superior Agrária de Santarém, with a pilot plant equipped with RO spiral wound modules, M38RO, from Alfa Laval, Denmark. The total membrane permeation area is 15 m2. The work pressure was 55 bar. The original must had 23.7 oBrix, a density of 1108 g.L-1, 15.2% (v/v) of probable alcohol, and a conductivity of 2.01 mS.cm-1. The must reconstitution was carried out, by mixing the concentrated grape must with the vegetal water produced by RO (permeate) to obtain beverages with a nominal alcohol content of 5%, 7%, 10% and 13% (v/v). The fermentation average temperature was between 18.2 and 19.7 °C, and the final density rounded about 993 g.cm-3. The beverages were analysed by different parameters, including total polyphenols, total anthocyanins, colour intensity and hue, the coordinates CIELab, alcohol content, total acidity, volatile acidity, pH, free SO2 and total SO2. The attributes of the beverage, corresponding to the visual appearance, aroma and taste senses, as well as the overall judgment were evaluated by the tasters. The proposed method can produce beverages with controlled low alcohol content. The decrease of the alcohol content led to lower content of polyphenols compounds which influenced the sensory evaluation.info:eu-repo/semantics/publishedVersio

    The Nomenclature of Medicinal Plants of Tuva in Dictionaries

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    The article introduces a list of sources which inform the reader of the plants used for medicinal purposes by Tuvan people. A brief analysis of these sources has revealed a necessity to distinguish between medicinal plants of Tuva and those used in traditional medicine of the Tuvans; and also between their names in Tuvan as the language of the indigenous people of the area, and in the language of the local Russian-speaking population, especially the Old Believers. There is an ongoing process of mutual enrichment of the range of medicinal plants known and used by Tuvans and Russians in the region (e.g., teve-kuduruu and chuksugbai are words borrowed by the local Russians from the Tuvans; and pantseria sherstistaya or kalendula have taken the opposite route – into Tuvan from Russian). On the whole, the names for medicinal plants in various sources are absolutely stable and do not raise any doubt - such as pion, mar’in koren — shengne (Eng. - peony), pikhta-choigan (Eng. - silver fir). Nevertheless, some dictionary entries may present a problem due to: a) absence of matching names in Tuvan-Russian and Russian-Tuvan dictionaries; b) difference of nomenclature for medicinal plants of Tuva in different sources; c) incongruity of descriptions leading to misunderstandings (orgaadai, smolevka/ Eng. campion); d) wrong versions of the plant’s name in translated dictionaries (khek-davan — podsnezhnik/ Eng. snowdrop instead of prostrel/eng. pasqueflower). The authors suggest that philologists should work out a methodology of processing plant names for a future trilingual (Russian, Latin and Tuvan) dictionary of Tuvan plants of varying household significance. This methodology should then be thoroughly tested, and the dictionary should feature colour illustrations. It is thus of utter importance to have Tuvan names of plants clarified, and literary norms and their dialectal differences clearly marked in order to write up correct entries for the new dictionaries, and ultimately, to build the dictionary of Tuvan plant names on this basis

    Ultrasonic evidence of an uncorrelated cluster formation temperature in manganites with first-order magnetic transition at T_C

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    Ultrasonic attenuation and phase velocity measurements have been carried out in the ferromagnetic perovskites La_{2/3}Ca_{1/3}MnO_3 and La_{2/3}Sr_{1/3}MnO_3. Data show that the transition at the Curie temperature, T_C, changes from first- to second-order as Sr replaces Ca in the perovskite. The compound with first-order transition shows also another transition at a temperature T* > T_C. We interpret the temperature window T_C < T < T* as a region of coexistence of a phase separated regime of metallic and insulating regions, in the line of recent theoretical proposals.Comment: 4 pages, 2 figure

    Multiferroic behavior in the new double-perovskite Lu2_2MnCoO6_6

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    We present a new member of the multiferroic oxides, Lu2_2MnCoO6_6, which we have investigated using X-ray diffraction, neutron diffraction, specific heat, magnetization, electric polarization, and dielectric constant measurements. This material possesses an electric polarization strongly coupled to a net magnetization below 35 K, despite the antiferromagnetic ordering of the S=3/2S = 3/2 Mn4+^{4+} and Co2+^{2+} spins in an \uparrow \uparrow \downarrow \downarrow configuration along the c-direction. We discuss the magnetic order in terms of a condensation of domain boundaries between \uparrow \uparrow and \downarrow \downarrow ferromagnetic domains, with each domain boundary producing a net electric polarization due to spatial inversion symmetry breaking. In an applied magnetic field the domain boundaries slide, controlling the size of the net magnetization, electric polarization, and magnetoelectric coupling

    Studying stellar binary systems with the Laser Interferometer Space Antenna using Delayed Rejection Markov chain Monte Carlo methods

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    Bayesian analysis of LISA data sets based on Markov chain Monte Carlo methods has been shown to be a challenging problem, in part due to the complicated structure of the likelihood function consisting of several isolated local maxima that dramatically reduces the efficiency of the sampling techniques. Here we introduce a new fully Markovian algorithm, a Delayed Rejection Metropolis-Hastings Markov chain Monte Carlo method, to efficiently explore these kind of structures and we demonstrate its performance on selected LISA data sets containing a known number of stellar-mass binary signals embedded in Gaussian stationary noise.Comment: 12 pages, 4 figures, accepted in CQG (GWDAW-13 proceedings

    The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive individuals

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    <p>Abstract</p> <p>Objective</p> <p>This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated.</p> <p>Methods</p> <p>Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2).</p> <p>Results</p> <p>168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209).</p> <p>Conclusions</p> <p>Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.</p

    Supersymmetric Froggatt-Nielsen Models with Baryon- and Lepton-Number Violation

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    We systematically investigate the embedding of U(1)_X Froggatt-Nielsen models in (four-dimensional) local supersymmetry. We restrict ourselves to models with a single flavon field. We do not impose a discrete symmetry by hand, e.g. R-parity, baryon-parity or lepton-parity. Thus we determine the order of magnitude of the baryon- and/or lepton violating coupling constants through the Froggatt-Nielsen mechanism. We then scrutinize whether the predicted coupling constants are in accord with weak or GUT scale constraints. Many models turn out to be incompatible.Comment: Final version, references added, minor corrections; LaTeX, 46 page

    Supersymmetric One-family Model without Higgsinos

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    The Higgs potential and the mass spectrum of the N=1 supersymmetric extension of a recently proposed one-family model based on the local gauge group SU(3)cSU(3)LU(1)XSU(3)_c \otimes SU(3)_L \otimes U(1)_X, which is a subgroup of the electroweak-strong unification group E6E_6, is analyzed. In this model the slepton multiplets play the role of the Higgs scalars and no Higgsinos are needed, with the consequence that the sneutrino, the selectron and six other sleptons play the role of the Goldstone bosons. We show how the μ\mu problem is successfully addressed in the context of this model which also predicts the existence of a light CP-odd scalar.Comment: REVTeX 4, 10 pages. Included discussions about constraints coming from the rho-parameter and from Muon (g-2). References added. Version to appear in Phys. Rev.

    The interplay between double exchange, super-exchange, and Lifshitz localization in doped manganites

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    Considering the disorder caused in manganites by the substitution of Mn by Fe or Ga, we accomplish a systematic study of doped manganites begun in previous papers. To this end, a disordered model is formulated and solved using the Variational Mean Field technique. The subtle interplay between double exchange, super-exchange, and disorder causes similar effects on the dependence of T_C on the percentage of Mn substitution in the cases considered. Yet, in La2/3_{2/3}Ca1/3_{1/3}Mn1y_{1-y}Gay_yO3_3 our results suggest a quantum critical point (QCP) for y0.10.2y\approx 0.1-0.2, associated to the localization of the electronic states of the conduction band. In the case of Lax_xCax_xMn1y_{1-y}Fey_yO3_3 (with x=1/3,3/8x=1/3,3/8) no such QCP is expected.Comment: 6 pages + 3 postscript figures. Largely extended discussio

    Is SAX J1808.4-3658 a Strange Star ?

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    One of the most important questions in the study of compact objects is the nature of pulsars, including whether they are composed of β\beta-stable nuclear matter or strange quark matter. Observations of the newly discovered millisecond X-ray pulsar \sax with the Rossi X-Ray Timing Explorer place firm constraint on the radius of the compact star. Comparing the mass - radius relation of \sax with the theoretical mass - radius relation for neutron stars and for strange stars, we find that a strange star model is more consistent with SAX J1808.4-3658, and suggest that it is a likely strange star candidate.Comment: 5 pages, Latex, 1 figure, corrected for some typo
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