Search results for " MATERIALI"
showing 10 items of 710 documents
Indentation test as a tool for monitoring the solidification process during injection molding
2003
An inline method for monitoring the solidi-fication process during the injection molding of semicrystalline polymers is demonstrated. The method has been applied to various poly(ethylene terephthalate) (PET) and poly(buthylene terephthalate) (PBT) samples. The technique is based on a simple device by which an additional ejector pin is pushed onto the injection-molded part with a fixed force at different times during the solidification phase while the mold remains closed. The residual deformation (the so-called indentation depth) due to the applied load is measured offline after ejection. By the performance of indentation at different times during the cooling phase, an indentation depth prof…
INNOVAZIONE TECNOLOGICA DI SISTEMI, COMPONENTI E MATERIALI
2016
Il fabbisogno energetico di un edificio è la somma dell’energia necessaria per il riscaldamento, il raffrescamento, la ventilazione e l’illuminazione. La somma di tali consumi incide fortemente sul bilancio energetico nazionale e, alla riduzione di tale incidenza, sono dedicate numerose ricerche. Alcune di queste sono tese all’individuazione di nuove fonti energetiche rinnovabili, altre alla riduzione dei consumi attraverso l’efficientamento dell’involucro degli edifici e al miglioramento degli impianti. Tutte queste ricerche sono tese all’efficientamento del consumo energetico in fase d’uso degli edifici, l’energia che si va a misurare è dunque detta Operating energy. La progettazione di u…
Electrochemical oxidation of tetramethoxy precursor as a key step for the synthesis of coenzyme Q10
2007
The feasibility of electrosynthesis of coenzyme Q10 (1) by electrooxidation of tetramethoxy precursor (2) has been investigated at carbon, Pt and BDD anodes in a divided cell. The process strongly depends on the applied potential, anode material and water content of the solvent. At carbon anodes in CH3CN/CH2Cl2 + 0.15 M Bu4NBF4 at proper operative conditions high faradic efficiency (>60%) and excellent selectivity (95–97%) of the target product were obtained. Keywords: Electrosynthesis, Coenzyme Q10, Anodic oxidation
Pyrolysed cork-geopolymer composites: A novel and sustainable EMI shielding building material
2019
Abstract In this investigation, and for the first time, pyrolysed sustainable cork was used to produce waste-based geopolymer-cork composites with enhanced electromagnetic interference (EMI) shielding properties. The influence of the pyrolysed cork amount and the geopolymer porosity on the EMI shielding ability of the composites was studied. The maximum total shielding effectiveness (SET) values achieved by these novel building materials (−13.8 to −15.9 dB) are equal to any other reported geopolymer microwave (MW) absorbers over the X-band, despite containing much lower carbon content. In addition, our composites were produced using an industrial waste (biomass fly ash) as raw material and …
Experimental and numerical evaluation of sandwich composite structures
2004
The main problem working with sandwich composite structures is their intrinsic anisotropy and non-homogeneity that does not allow their correct modelling. Nowadays the available data on mechanical properties of complex structures, necessary to allow a correct and reliable design, are not sufficient. The aim of the present work is to extend the knowledge of mechanical properties both on single components and on complete structures, focusing on the effects induced by different kind of skin arrangements (Kevlar, glass and carbon fibres). Compressive, shear and flexural tests were performed for a complete static mechanical characterisation of the sandwich structure both on each single component…
Involucri Edilizi Sostenibili. Impiego di materiali tecnologicamente avanzati per l’ottimizzazione energetica e l’incremento prestazionale degli elem…
2013
La ricerca della migliore esposizione dell’edificio, grazie alla quale minimizzare l’apporto solare sulle facciate; l’impiego di specifici elementi captanti; la scelta dei materiali più idonei -per caratteristiche e prestazioni- al contenimento dei consumi energetici, sono solo alcuni degli aspetti. che entrano in gioco nel progetto di un involucro edilizio e, più in generale, di una architettura sostenibile. L’involucro edilizio, tra tutti gli elementi (tecnici) che conformano l’edificio, è quello che maggiormente interagisce con le “condizioni al contorno” (siano esse climatiche, urbane, sociali, economiche, ecc); da queste, infatti, trae spesso ispirazione per la sua stessa messa in form…
Evaluation of innovative thermal insulation systems for a sustainable envelope
2017
La memoria presenta i risultati ottenuti su sistemi di isolamento termico per l’involucro edilizio. Si presentano i risultati ottenuti tramite simulazioni informatiche che hanno consentito di verificare e ottimizzare la trasmissione del calore attraverso un sistema sottovuoto in vetro per le facciate trasparenti. Inoltre la possibilità offerta dal riciclo del materiale di scarto della potatura dell’Opunthia Ficus Indica (fichi d’india) che,opportunamente trattato ha permesso di ottenere un materiale isolante (Brevetto n. 1402131), in forma di pannello o in grani sfusi, (valori di coibenza termica 0.0710.057 W/mK). The paper presents the results of the research on thermal insulation systems…
Spekülatif Materyalizmde Hümanizm Ve Post-Hümanizm
2018
Measure of a limestone weathering degree using Laser Scanner.
2013
The weathering degree of the building materials and natural stones is generally quantified as the decrement of some mechanical features that can be measured experimentally by means of compressive tests or point load tests in the laboratory or Schmidt hammer tests carried out in situ. Such destructive or damaging tests are unacceptable in case of cultural heritage since even small amounts of damage must be avoided. This work shows a correlation between Schmidt hammer rebound values and the reflectivity that is detected by means of terrestrial scanner laser; therefore it allows assessing the weathering degree of buildings or stones in situ. The results demonstrate that such an investigation c…
Ultra-fast-prototyping of PMMA structures for micro-engineering applications: Choosing the right material
2017
Machining of poly(methyl methacrylate) (PMMA) by laser has been extensively studied in engineering research for several applications including microfluidic manufacturing and rapid prototyping. However, very few investigations have taken into consideration the wide range of physico-chemical characteristics of commercially available PMMA that can often affect the quality of the laser-machined structures. These characteristics are often ignored, with many manufacturing publications focusing on a single source of PMMA. To understand the different bonding strengths and laser-cut qualities in the context of our ultra-fast prototyping technique, four types of PMMA have been examined. Molecular wei…