8,864 research outputs found
Characterization of phenolics in Lacrima di Morro d'Alba wine and role on its sensory attributes
No full text
Thermal modeling of industrial-scale vanadium redox flow batteries in high-current operations
No full textA cell-resolved model that simulates the dynamic thermal behavior of a Vanadium Redox Flow Battery during charge and discharge is presented. It takes into account, at a cell level, the reversible entropic heat of the electrochemical reactions, irreversible heat due to overpotentials, self-discharge reactions due to ion crossover, and shunt current losses. The model accounts for the heat transfer between cells and toward the environment, the pump hydraulic losses and the heat transfer of piping and tanks. It provides the electrolyte temperature in each cell, at the stack inlet and outlet, along the piping and in the tanks. Validation has been carried out against the charge/discharge measurements from a 9kW/27kWh VRFB test facility. The model has been applied to study a VRFB with the same stack but a much larger capacity, operating at 400 A for 8 h, in order to identify critical thermal conditions which may occur in next-generation industrial VRFB stacks capable to operating at high current density. The most critical condition has been found at the end a long discharge, when temperatures above 50°C appeared, possibly resulting in 〖VO〗_2^+ precipitation and battery faults. These results call for heat exchangers tailored to assist high-power VRFB systems
Influence de certains souches de levures sur les composants volatils des eaux de vie de vin: evaluation statistique des donées
No full textRelationship between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches
No full textBACKGROUND
The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph–mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported.
RESULTS
Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties (‘green–fruity’ and ‘sweet’) and olfactory perception.
CONCLUSION
Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation
Evaluation of Some Fixed Components for Unifloral Honey Characterization
No full textThe classification of honeys according to their botanical origin is a problem usually solved by means of microscopic observation of pollens and by evaluation of organoleptic characteristics such as color, taste, and others. In this paper, a number of chemical parameters including water activity, free amino acid composition, reducing sugars, total sugars, and pH were evaluated for a number of samples of some different botanical origin honeys. The results were evaluated by chemometric methods, and this allowed discrimination between the different origins, also for some critical cases such as chestnut and lime tre
Andrea Bacová
No full textAndrea Bacová focuses on research and teaching in the field of residential architecture. Her work includes systematic research on residential buildings and their urban context. She actively participates in promoting Slovak architecture and is the author of several publications and exhibitions
Viewer-, Author-, and Ownership in the Work of Andrea Zittel
No full textAndrea Zittel invites others to collapse the distinctions between artist, viewer, and collaborator by interacting with her usable works. This thesis explores the process of interacting with Zittel\u27s works, and how it affects viewer-, author- and ownership
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