Search results for "Degradation process"
showing 10 items of 12 documents
1990
This lecture summarizes some recent results and ideas about interrelations between degradation and mechanical behaviour of polyolefins. Aspects of the heterogeneous nature of oxidative degradation in the solid state, the feedback mechanism in degradation, effects of morphology, particularly orientation, on the degradation process, and the influence of degradation on plasticity and on the ultimate mechanical behaviour are discussed.
Quercetin as natural stabilizing agent for bio-polymer
2014
The introduction of antioxidants in polymers is the main way to prevent or delay the degradation process. In particular natural antioxidants receive attention in the food industry also because of their presumed safety. In this work bio-polymers, i.e. a commercial starch-based polymer (Mater-Bi®) and a bio-polyester (PLA), and a bio-polyether (PEO) were additivated with quercetin, a natural flavonoid antioxidants, in order to formulate bio-based films for ecosustainable packaging and outdoor applications. The photo-oxidation behavior of unstabilized and quercetin stabilized films was analyzed and compared with the behavior of films additivated with a commercial synthetic light stabilizer. Th…
Le statue rinascimentali di palazzo Abatellis: caratterizzazione delle dorature e dei pigmenti tramite spettrometria XRF.
2010
Condition Monitoring Technologies for Synthetic Fiber Ropes - a Review
2020
This paper presents a review of different condition monitoring technologies for fiber ropes. Specifically, it presents an overview of the articles and patents on the subject, ranging from the early 70’s up until today with the state of the art. Experimental results are also included and discussed in a conditionmonitoring context,where failuremechanisms and changes in physical parameters give improved insight into the degradation process of fiber ropes. From this review, it is found that automatic width measurement has received surprisingly little attention, and might be a future direction for the development of a continuous condition monitoring system for synthetic fiber ropes.
Metabolism of stilbene phytoalexins by Botrytis cinerea: 1. Characterization of a resveratrol dehydrodimer
1998
Abstract Resveratrol, a grapevine phytoalexin, is metabolized by a laccase-like stilbene-oxidase of Botrytis cinerea, the causal organism for grey mould. Characterization of one major metabolite formed during this degradation process as a resveratrol dehydrodimer allowed us to precize the reaction mechanism of this enzyme on stilbenes.
Visually low-impacting methods for the measurement of parameters related to IAQ risk indicators in exhibition halls
2021
Microclimate for cultural heritage plays a fundamental role in the degradation process of artefacts exhibited in museums. Generally, the Indoor Air Quality (IAQ) monitoring inside museums is based on conventional measurements of thermo-hygrometry parameters and longtime averaged measurements of atmospheric pollutants’ concentration. Unfortunately, all these approaches require electric supply and are usually characterized by a noticeable visual impact on the exhibition space, which clearly negatively affects the visitors’ experience. This paper intends to revisit and discuss a methodology (and its test application on field, to estimate the risk of damage of three artefacts displayed in an ol…
L'incremento della sostenibilità ambientale attraverso una corretta gestione dell'irrigazione.
2014
Lo scopo di questo lavoro è quello di mettere a punto, a partire dalle informazioni territoriali quali caratteristichemeteorologiche e pedologiche, uno studio capace di valutare la sostenibilità della gestione irrigua in tre ipotetiche parcelle sperimentali individuate nel territorio del sottobacino Iudeo-Bucari (TP). Sitratta di tre vigneti che rappresentano per caratteristiche morfologiche e gestionali l'intero sottobacino, ovvero una delle aree maggiormente vitate della Sicilia. Il fine è valutare la sostenibilità della gestione irrigua in termini di risparmio energetico, attraverso l'applicazione del modello di bilancio idrico FAO 56. Questo tipo di studio pone le basi per la redazione …
A comparative thermogravimetric study of waterlogged archaeological and sound woods
2010
Waterlogged archaeological woods Pinus pinaster and Fagus sylvatica L. were analyzed by using TG technique. Degradation processes ascribable to the holocellulose decay were evidenced at nearly the same temperature for sound and archaeological samples. The residual matters at 600 and 900 °C of the sound woods are much lower than those of archaeological waterlogged woods in agreement with the presence of inorganic materials encapsulated during the burial into the marine environment. It was proposed a new protocol to rapidly calculate the maximum water content parameter, which is related to the wood degradation state. TG experiments at variable heating rates were performed to obtain kinetic pa…
Anthelminthische Wirkstoffe, 5. Mitt.: Langkettig und hydroheterocyclisch substituierte Chlor-diallylamino-1,3,5-triazine
1988
Aus der Umsetzung von 2,4-Dichlor-6-(diallylamino)-1,3,5-triazin (1) mit den aliphatischen Aminen 2a–c gehen die langkettig substituierten Chlordiallylamino-1,3,5-triazine 3a–c, mit den Piperazinen 4a–c die hydroheterocyclisch substituierten Chlor-diallylamino-1,3,5-triazine 5a–c, hervor. Unter den zur Strukturcharakterisierung herangezogenen spektroskopischen Daten ist besonders in den Massenspektren des Strukturtyps 5 die Abspaltung des Neutralteilchens Phenyl-NH2 unter Ausbildung des Radikalkations bei m/z 277 auffallig. 3 und 5 zeichnen sich durch anthelminthische, trichomonazide, insektenwachstumsregulatorische und fiebersenkende Wirkungen aus. Anthelminthic Agents, V: Chloro(diallylam…
Passive Behavior and Passivity Breakdown of AISI 304 in LiBr Solutions through Scanning Electrochemical Microscopy
2014
The passive behavior and passivity breakdown of AISI 304 stainless steel in LiBr solutions has been investigated by means of scanning electrochemical microscopy (SECM). The sample generation - tip collection (SG-TC) mode was used to operate the SECM and the tip potential was biased to detect the electroactive species. The evolution of the current at the ultramicroelectrode tip with the applied potential within the passive range was followed at different LiBr concentrations. Results show that the absolute value of the current at the tip increases with the applied potential. Additionally, SECM was also used to detect stable pits formed on the stainless steel surface in a 0.2 M LiBr solution. …