1,190 research outputs found

    Rheological investigation and simulation of a debris-flow event in the Fella watershed

    Get PDF
    Abstract. To set an approach for the future territorial planning, the Geological Survey of Friuli Venezia Giulia Region, through the researchers of Trieste University, started a program of debris-flow risk analysis using Flo-2D software as tool to delimit the hazardous areas. In the present paper, as a case study, a debris flow, called Fella sx, occurring in a torrent catchment was analyzed. The choice was due to the abundance of information about past events, inundated areas, rain fall, geology and to its representativeness. An initial back-analysis investigation identified a couple of representative rheological parameters. Riverbed samples were collected, sieve analyses were performed and rheological tests were carried out on the fraction finer than 0.063 mm using a rotationally controlled stress rehometer equipped with the serrated parallel plate geometry. The shear dependent behaviour was examined at different concentrations ranging from 33 to 48%, by weight. Viscosity data treatment was performed to determine the most suitable rheological model to provide the best approximation of the debris-flow behaviour. The rheological parameters, derived from experimental data, were used and compared with those obtained through the back-analysis and with the real inundated area. Data obtained through rheological analysis are useful in constructing scenarios of future events where no data for back-analysis are available

    Quantitative analysis of headspace volatile compounds using comprehensive two-dimensional gas chromatography and their contribution to the aroma of Chardonnay wine.

    Get PDF
    The quantitative determination of volatile compounds of Chardonnay wines using HS-SPME-GC × GC/TOFMS along with the determination of odor activity value (OAV) and relative odor contribution (ROC) of volatiles are reported for the first time. The use of GC × GC/TOFMS for the analysis of Chardonnay wine of Serra Gaucha resulted in the tentative identification of 243 compounds, showing the superior performance of this analytical technique for this specific varietal wine, considering that the number of compounds usually separated by 1D-GC for this type of wine is lower. Furthermore, 42 compounds co-eluted in the first dimension and 34 of them were separated in the second dimension, while the others were resolved by spectral deconvolution (8), which indicates that the conventional 1D-GC/MS may result in misleading results. The calculation of OAV and ROC allowed the determination of the volatile compounds that presented the greater contribution to wine aroma. Ethyl octanoate, ethyl hexanoate, ethyl butanoate, and beta-damascenone showed the highest OAV and ROC values, although other 43 compounds showed also potential to contribute to wine aroma. Figures of merit of the developed method were: accuracies from 92.4 to 102.6%, repeatability from 1.2% to 13.4%, LOD from 0.001 ?g L?1 (ethyl isovalerate and hexanoic acid) to 2.554 ?g L?1 (ethyl 3-hydroxybutanoate), LOQ from 0.003 ?g L?1 (ethyl isovalerate and hexanoic acid) to 7.582 ?g L?1 (ethyl 3-hydroxybutanoate)

    Determination of the possible contribution to aroma using odor activity values of volatile compounds of wines analyzed by comprehensive two dimensional gas chromatography.

    Get PDF
    The aim of this study was to use the HS-SPME-GC × GC/TOFMS to quantify volatile compounds of wines produced with Chardonnay grapes in Serra Gaúcha region, Brazil and determine their possible contribution to aroma through the determination of OAV for each tentatively identified compound

    Non-invasive methodological approach to detect and characterize high-risk sinkholes in urban cover evaporite karst: Integrated reflection seismics, PS-INSAR, leveling, 3D-GPR and ancillary data. a Ne Italian case study

    Get PDF
    Sinkholes linked to cover evaporite karst in urban environments still represent a challenge in terms of their clear identification and mapping considering the rehash and man-made structures. In the present research, we have proposed and tested a methodology to identify the subsiding features through an integrated and non-invasive multi-scale approach combining seismic reflection, PS-InSAR (PSI), leveling and full 3D Ground Penetrating Radar (GPR), and thus overpassing the limits of each method. The analysis was conducted in a small village in the Alta Val Tagliamento Valley (Friuli Venezia Giulia region, NE Italy). Here, sinkholes have been reported for a long time as well as the hazards linked to their presence. Within past years, several houses have been demolished and at present many of them are damaged. The PSI investigation allowed the identification of an area with higher vertical velocities; seismic reflection imagined the covered karst bedrock, identifying three depocenters; leveling data presented a downward displacement comparable with PSI results; 3D GPR, applied here for the first time in the study and characterization of sinkholes, defined shallow sinking features. Combining all the obtained results with accurate field observations, we identified and mapped the highest vulnerable zone

    Anthropometric comparison between young Estonian and Chinese swimmers

    Get PDF
    Due to the progressive lowering of the age of peak performance among swimmers, it became important to better understand the factors influencing performance in prepuberal boys and girls. Aim of this study is to compare two different racial/ethnic groups of young swimmers, one from Nord-Europe, Estonia (Tartuma Region), and the other from China (Shanghai District) in order to assess existing differences in respect to body dimension, body fat, technical parameters of swimming performance and maximum lactate production. 26 Estonian and 7 Chinese female and 25 Estonian and 10 Chinese male, from two swimming schools, took part in the study. Anthropometric parameters were measured in accord with ISAK guidelines. BMI, Stroke Index, Stroke Length, mean velocity on a 200 m freestyle all out, and blood lactate after three minutes were measured. Significant differences exist in anthropometry between Nord-European and Asian young swimmers. These differences are more pronounced in female, with higher fat tissue in Nordic girls. Leg lengths are different between Chinese and Estonian girls having the Estonian longer legs. Hands lengths are different both in male and in female subjects. Being the Chinese groups of higher level of performance (higher mean velocity in the 200 m freestyle, such differences seems not to be as major determinants of the performance, also if they are often indicated as determinants of buoyancy and stroke efficiency

    Phenolic content, physical-chemical composition and antioxidant activity of Syrah wines elaborated in São Francisco Valley during ripening.

    Get PDF
    The present work aimed to study the phenolic content, physical-chemical composition and antioxidant activity of red wines cv Syrah prepared from grapes harvested at different stages of ripeness
    corecore