17 research outputs found

    Surface oxidation of liquid Sn

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    We report the results of an x-ray scattering study that reveals oxidation kinetics and formation of a previously unreported crystalline phase of SnO at the liquid-vapour interface of Sn. Our experiments reveal that the pure liquid Sn surface does not react with molecular oxygen below an activation pressure of \~5.0*10-6 Torr. Above that pressure a rough solid Sn oxide grows over the liquid metal surface. Once the activation pressure has been exceeded the oxidation proceeds at pressures below the oxidation pressure threshold. The observed diffraction pattern associated with the surface oxidation does not match any of the known Sn oxide phases. The data have an explicit signature of the face-centred cubic structure, however it requires lattice parameters that are about 9% smaller than those reported for cubic structures of high-pressure phases of Sn oxides. Keywords: X-ray scattering, diffraction, and reflection; Oxidation; Surface chemical reaction; Surface structure, morphology, roughness, and topography; Tin; Tin oxides; Liquid surfaces; Polycrystalline thin filmsComment: 18 pages, 6 figures, 1 table; Submitted to Surface Scienc

    Contrast enhanced ultrasound of renal masses

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    Contrast enhanced ultrasound (CEUS) has gained clinical importance over the last years for the characterization of hepatic masses. Its role in extrahepatic indications has been investigated repeatedly but has been less comprehensively studied. Currently more than 50% of renal masses are incidentally diagnosed, mostly by B-mode ultrasound. The method of choice for characterization of renal lesions is contrast enhanced computed tomography (CECT). In the case of cystic lesions CECT refers to the Bosniak classification for cystic lesions to assess the risk of malignant behavior. The majority of masses are renal cell carcinoma, but the exact proportion is controversial. Disadvantages of CECT are a significant risk for patients with impaired renal function, allergic reactions and hyperthyroidism due to iodinated contrast agents. Several studies concerning CEUS for the characterization of both solid and cystic renal lesions have been published, but prospective multicenter studies are missing, the presented data being mainly descriptive. The aim of the this manuscript is to review the current literature for CEUS in renal masses, to summarize the available data and focus on possible concepts for studies in the future

    Cooling Shock for Bottled Wine. How Dramatic Is This before Tasting?

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    Adjusting the wine temperature is a routine procedure before opening a wine bottle. In many situations wine requires quick cooling, which occasionally raises disturbing questions among consumers and wine professionals. In particular, there are certain concerns that too rapid cooling of wine for some reasons may negatively affect its sensory characteristics and compromise the wine evaluation. To scientifically confirm of disprove this myth, we conducted a sensory analysis of six wines, cooled slowly in a refrigerator and quickly in an ice–water–salt mixture. Two sparkling wines, two white, and two red still wines with different aroma profiles were included in the research. Results of the triangle tests and 3-AFC tests demonstrated no perceivable differences between the quickly and slowly cooled wine samples. These outcomes may be useful for scientists, who perform wine sensory evaluations, as well as wine producers, experts, and the foodservice industry in general

    Strategies for the sensorial optimization of alcohol-free wines

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    De-alcoholized wines are currently experiencing an increasing demand, but are also being discussed very controversially at this time. The de-alcoholization process is usually carried out by distillation processes under vacuum. The treatment is accompanied by a series of changes in terms of analytical and sensory parameters of the wines. Ethanol has a very complex and far ranging influence on the wine sensory character. Even more, the de-alcoholization process goes along with certain losses of aroma components. Several strategies were assessed to buffer and balance the effect of de-alcoholizing wines below 0.5% v/v. Compared to the addition of tannins and mannoproteins, sweetening showed clearer results on the panelist’s preference. The assessment of a commercial resin treatment to recover aroma from de-alcoholization process showed promising results

    Potential wine ageing during transportation

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    In a global world, wineries have to satisfy the demand of consumers who wish to drink high quality wines from countries all over the world. To fulfill this request wines have to be transported, crossing thereby great distances from the place of production to the consumer country. At the Institute of Enology of Hochschule Geisenheim University examinations with White-, Rosé- and Red-Wines of different origins which had been transported over longer distances within Europe (Portugal, France, Italy to Germany) by trucks were carried out. Shipping of wines was simulated in a climatized cabinet to analyze the influence on wine quality during this way and conditions of transportation. Time and temperature profiles were based on real transport situtations which were recorded during shipping from Germany to Japan using data loggers. White, Rosé and Red wines were transported during 6 to 8 weeks and then were analytically and sensorically compared to those which were stored at a constant temperature of 15 ∘C. Besides the effect of temperature, the movements and vibrations encountered by the wines were also examined. Analytically wines were analyzed for general analytical parameters with Fourier-Transformation-Infrared-Spectroscopie (FTIR), Colour differences (Spectralphotometrie) and free and total sulfuric acid with Flow-Injection-Analysis (FIA). Sensory examinations with a trained panel were performed in difference tests in form of rankings and triangular tests. Summarizing the results from the different tests it could be found that transportation had an influence on the potential ageing of wines depending on the wine matrix. Especially high and varying temperatures during transportations over a longer distance and time had negative influences on wine quality. Also the movement of wine at higher temperatures had showed a negative effect whereas transport at cool temperatures even below 0 ∘C did not influence wine characteristics. Sophisticated, younger white and lighter wines with distinct levels of carbon dioxide showed tendencially clearer analytical and sensorical differences between transported and non-transported samples

    State-of-the-Art Knowledge about 2,4,6-Trichloroanisole (TCA) and Strategies to Avoid <em>Cork Taint</em> in Wine

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    Cork stoppers have been used for many centuries to seal wine in various vessels. Therefore, corks have become a traditional part of wine packaging in many countries and still play an important role for the entire wine industry. Nowadays, there is a wide option of bottle cork stoppers on the market, such as natural corks, agglomerated and technical stoppers (1 + 1), etc. These cork closures have a number of advantages, including positive sustainable and ecological aspects. Natural cork material can also be responsible for cork taint, which imparts musty/moldy or wet cardboard off-odors to the wine. However, corks are not the only source of cork taint in wine, as will be shown in the present chapter. Over the past decades, a number of compounds have been detected that can contribute to the cork taint. Among them, haloanisoles play a major role, in particular 2,4,6-trichloroanisole (TCA), which has been shown to be responsible for 50–80% or more of musty defect cases in wine. Currently, the cork and wine industries have developed a number of tools and technologies to effectively prevent cork tait in wine or to remove it if the wine is already contaminated. These practical as well as analytical questions about the TCA defects are the subject of the actual chapter

    Ultrafast and Energy-Efficient Quenching of Spin Order: Antiferromagnetism Beats Ferromagnetism

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    By comparing femtosecond laser pulse induced ferro- and antiferromagnetic dynamics in one and the same material-metallic dysprosium-we show both to behave fundamentally different. Antiferromagnetic order is considerably faster and much more efficiently reduced by optical excitation than its ferromagnetic counterpart. We assign the fast and extremely efficient process in the antiferromagnet to an interatomic transfer of angular momentum within the spin system. Our findings imply that this angular momentum transfer channel is effective in other magnetic metals with nonparallel spin alignment. They also point out a possible route towards energy-efficient spin manipulation for magnetic devices

    Analytische Explikationen & Interventionen

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    Philosophie nach Georg Meggle zeichnet sich aus durch kom - munikative Offenheit, durch begriffliche Unbestechlichkeit und durch ihr Engagement in der Welt. Die Beiträge in diesem Band orientieren sich an diesem Philosophieverständnis und sind aus Anlass eines Symposiums zu Ehren von Georg Meggle als Originalbeiträge geschrieben worden. Der Band verbindet die theoretischen und praktischen Aspekte der analytischen Philosophie: So sind die Essays zur Hälfte der theoretischen, meist sprach-analytischen, zur Hälfte der praktischen, meist praktisch-politischen Philosophie zuzuordnen. Die Texte vereint das Ideal des Strebens nach begrifflicher Klarheit und welthaltiger Relevanz, nach Dialog. Sie beschreiten neue Wege der analytischen Philosophie und weisen somit den Weg in die Zukunft der Philosophie als gesellschaftlich relevanter Disziplin. Mit Beiträgen u.a. von: Franz von Kutschera, Peter Singer, Wolfgang Lenzen, Wolfgang Spohn, Reinhard Merkel, Rainer Hegselmann, Peter Rohs und Georg Meggle
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