Generazione di energia con coppie termoelettriche in veicoli stradali dai gas di scarico

L’uso razionale delle risorse è da sempre un’esigenza alla quale il genere umano, ha dovuto far fronte. La rapida crescita di domanda energetica pro-capite, abbinata ad un calo delle stime di autonomia petrolifera, apre nuove sfide nella gestione energetica. Nel processo di conversione dell’energia, circa i due terzi vengono dispersi in calore, in parte (prevalente) allo scarico. L’evoluzione tecnologica dei materiali e di produzione ha permesso di realizzare dispositivi chiamati “moduli termoelettrici” che consistono in assemblati di termocoppie, con discrete caratteristiche di efficienza. Questi dispositivi sono in grado per mezzo dell’effetto Seebeck, di produrre corrente elettrica se sottoposti ad un gradiente di temperatura tra le due facce . Oltre a consentire la conversione quasi diretta di potenza termica in elettrica (a meno di convertitori elettronici), non presentano organi in movimento, il che lascia supporre, almeno dal punto di vista meccanico, una buona affidabilità. Lo studio si propone come obiettivo, la modellazione di un termogeneratore realizzabile con dispositivi commerciali, da applicare nel tubo dei gas di scarico di veicoli stradali, al fine di sfruttarne l’energia altrimenti persa allo scarico. Tale energia, recuperata e immessa nel sistema elettrico di bordo, può essere direttamente utilizzata per i carichi, o immagazzinata nel sistema di accumulo

Evaluation of Aglianico grape skin and seed polyphenols astringency by SDS-PAGE electrophoresis of salivary proteins after the binding reaction

SDS–PAGE electrophoresis and densitometry analysis were carried out to evaluate the reactivity of Aglianico red grape skin and seed polyphenols with human salivary proteins in order to find a method able to assess their astringency. Analysis of the supernatant obtained after a tannin/human salivary protein binding assay and sensorial analysis showed that four proteins, lactoferrin, PRPbg1, PRPbg2 and a-amylase, were the proteins best able to distinguish tannin solutions characterised by different levels of astringency. A correlation between densitometric data and tannin concentration was plotted in order to give an indirect measure of astringency. The two sources of Aglianico grape polyphenols differed from each other in astringency power; the seed extract solution was about two-fold more tannic than the skin one. The difference in astringency was also perceived by sensorial analysis. The results from this study show that SDS–PAGE electrophoresis of human salivary proteins after the binding reaction with grape polyphenol extracts, coupled with densitometric analysis and the use of a calibration curve, looks extremely promising as a new approach to evaluate polyphenol astringency

Performance of a protein extracted from potatoes for fining of white musts

In this study, the potentiality of Patatin (P), a protein extracted from potato, as must fining agent was investigated on musts obtained from two South Italy grape cultivars (Falanghina and Greco). Besides P, fining agents as bentonite (B) and potassium caseinate (C) were assayed at different concentrations. The rate of sedimentation, the decline of turbidity during time, the absorbance at 420 nm, the GRP (grape reaction products) and hydroxycinnamic acids (HCA) concentrations were determined. The comparative trials showed that P is a suitable fining agent to prevent browning and decrease haze during must settling because its effect on grape phenolics, brown pigments and turbidity is comparable and/or better than that detected for C. Its use as single fining agent or in combination with B depends on must characteristics

trans-Resveratrol, Quercetin, (+)-Catechin, and (-)-Epicatechin Content in South Italian Monovarietal Wines: Relantionship with Maceration Time and Marc Pressing during Winemaking

The concentrations of trans-resveratrol, (+)-catechin, (-)-epicatechin, and quercetin were evaluated by means of high-performance liquid chromatography-diode array detection in red wines obtained from Aglianico, Piedirosso, and Nerello Mascalese grapes. The trans-resveratrol and epicatechin concentrations did not differ significantly between experimental wines. The concentration of quercetin in Nerello Mascalese wines was more than twice that observed in Aglianico and Piedirosso wines. Nerello Mascalese wines also significantly differed from other wines in the (+)-catechin content, which was significantly higher than those found in the other two wines. During maceration, the maximum extraction of trans-resveratrol was reached after 12 days for Aglianico and Piedirosso, after which a decline was observed. On the contrary, in the case of Nerello Mascalese, the concentration of trans-resveratrol increased steadily throughout the whole maceration process. After 2 days of maceration, the maximum concentration of quercetin was observed in Aglianico must, whereas the maximum quercetin extraction was reached after 12 days for Piedirosso and 17 days for Nerello Mascalese. The maximum levels of (+)-catechin and (-)-epicatechin were generally observed after 12 days of maceration for all wines, although a decline of (-)-epicatechin occurred after maximum extraction in Aglianico and Piedirosso wines. Following marc pressing, a significant increase in the concentration of trans-resveratrol for Aglianico, (+)-catechin and (-)-epicatechin for Piedirosso, and (-)-epicatechin for Nerello Mascalese was observed

Saliva from obese individuals suppresses the release of aroma compounds from wine.

BackgroundRecent evidence suggests that a lower extent of the retronasal aroma release correspond to a higher amount of ad libitum food intake. This has been regarded as one of the bases of behavioral choices towards food consumption in obese people. In this pilot study we investigated the hypothesis that saliva from obese individuals could be responsible for an alteration of the retro-nasal aroma release. We tested this hypothesis in vitro, by comparing the release of volatiles from a liquid food matrix (wine) after its interaction with saliva from 28 obese (O) and 28 normal-weight (N) individuals.Methods and findingsAmplicon sequencing of the 16S rRNA V4 region indicated that Firmicutes and Actinobacteria were more abundant in O, while Proteobacteria and Fusobacteria dominated in N. Streptococcaceae were significantly more abundant in the O subjects and constituted 34% and 19% on average of the saliva microbiota of O and N subjects, respectively. The Total Antioxidant Capacity was higher in O vs N saliva samples. A model mouth system was used to test whether the in-mouth wine aroma release differs after the interaction with O or N saliva. In O samples, a 18% to 60% significant decrease in the mean concentration of wine volatiles was detected as a result of interaction with saliva, compared with N. This suppression was linked to biochemical differences in O and N saliva composition, which include protein content.ConclusionMicrobiological and biochemical differences were found in O vs N saliva samples. An impaired retronasal aroma release from white wine was detected in vitro and linked to compositional differences between saliva from obese and normal-weight subjects. Additional in vivo investigations on diverse food matrices could contribute to understanding whether a lower olfactory stimulation due to saliva composition can be a co-factor in the development/maintenance of obesity

Bacterial biofilm associated with a case of capsular contracture

Capsular contracture is one of the most common complications of implant-based breast augmentation. Despite its prevalence, the etiology of capsular contracture remains controversial although the surface texture of the breast implant, the anatomical position of the prosthesis and the presence of bacterial biofilm could be considered trigger factors. In fact, all medical implants are susceptible to bacterial colonization and biofilm formation. The present study demonstrated the presence of microbial biofilm constituted by cocci in a breast implant obtained from a patient with Baker grade II capsular contracture. This suggests that subclinical infection can be present and involved in low-grade capsular contracture

Biochemical features of native red wines and genetic diversity of the corresponding grape varieties from Campania Region

Campania region has always been considered one of the most appreciated Italian districts for wine production. Wine distinctiveness arises from their native grapevines. To better define the chemical profile of Campania autochthonous red grape varieties, we analysed the phenolic composition of Aglianico di Taurasi, Aglianico del Vulture, Aglianico del Taburno, Piedirosso wines, and a minor native variety, Lingua di Femmina in comparison with Merlot and Cabernet Sauvignon, as reference cultivars. A genetic profiling was also carried out using microsatellite molecular markers with high polymorphic and unambiguous profiles. Principal component analysis applied to 72 wines based on the 18 biochemical parameters, explained 77.6% of the total variance and highlighted important biological entities providing insightful patterns. Moreover, comparison of SSR-based data with phenylpropanoid molecules exhibited a statistically significant correlation. Our approach might be reasonably adopted for future characterisations and traceability of grapevines and corresponding wines

Investigating physicochemical, volatile and sensory parameters playing a positive or a negative role on tomato liking

This study aimed at providing further insights into the positive and negative drivers of tomato liking. For this purpose, 13 tomato cultivars representing different typologies were characterized for physicochemical parameters and aroma volatiles, and were assessed by a trained panel for sensory descriptors, and by Italian consumers for liking. The relationships among the different parameters and their effects on consumer liking were studied by Partial Least Squares (PLS) analysis. Among physicochemical traits and sensory descriptors, seeds, reducing sugars, firmness, thick epicarp, soluble solids, sour taste, total acidity, citrate, herbaceous aroma and brightness were found to be drivers of liking, whereas pulp thickness, humidity, fruit weight, diacetyl-like odor and mealiness showed an opposite influence. For the aroma volatiles, 2-isobutylthiazole played a key role on liking and its positive contribution seemed to be supported by (Z)-3-hexen-1-ol, but suppressed by 6-methyl-5-hepten-2-ol, especially when tomatoes had a poor volatile fraction. These results represent a contribution to the knowledge that could lead to more effective breeding strategies aimed at improving tomato sensory quality. (c) 2012 Elsevier Ltd. All rights reserved

Ocorrência de Megastigmus sp. (Hymenoptera: Torymidae) parasitoide da vespa da galha Leptocybe invasa (Hymenoptera: Eulophidae) no Brasil.

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