1,720,995 research outputs found
A participatory approach to the evaluation of acoustic behavior of national building techniques
No full textSistema 3D di posizionamento microfonico applicato a indagini di rumore delle macchine
No full textUn innovativo sistema di localizzazione tridimensionale della posizione è stato applicato alle misure del rumore emesso da un motore ibrido Diesel-elettrico Toyota. Il sistema di misura della posizione consente di ottenere le coordinate spaziali di una sonda intensimetrica, utilizzata per valutare in modo accurato e direzionale le emissioni sonore. In questo modo è stato possibile creare mappe, divise per bande di frequenza, delle emissioni della macchina e trovare eventuali punti critici
Mixing materials in false ceilings to increase sound diffusion in education spaces
No full textAccording to the International standards on education spaces, in situ acoustic tests should achieve specific reverberation time targets. Since the match between predictive formulas and measurements increase with the sound field diffuseness, it is extremely important to pursue such condition through proper design choices. For example, false ceilings can play a key role in controlling room acoustic features; however, the use of such elements is generally considered only for absorption purposes. For this reason, the present work concerns mixing materials in false ceilings within a group of teaching spaces here taken as case studies. The alternation of materials with different acoustic impedances has been investigated through experimental acoustic measurements and numerical models in order to assess the related sound diffusion increase. The ceiling treatment here proposed proved to be an efficient and smart method to exploit diffraction effects along material discontinuities junctions. The match between early design predictive formulas and the results of the acoustic measurements enhanced the reliability of the acoustic design process and set up a potential new guideline for indoor acoustic treatments
Contribution to thermal and acoustic characterization of corn cob for bio-based building insulation applications
Full text linkThe introduction of the sustainability principle in building design is driving more and more the research towards the development of thermal and acoustic building insulating materials using natura or recycledbased materials and reducing as small as possible energy consumptions during the processes. In this context, among the mostly investigated materials, the corn cob plays an important role although its applications for insulation purposes are not yet fully developed. Moreover, the corn cob is often investigated as an aggregate of composite materials, therefore its own thermal characteristics are scarcely investigated. The goal of the paper is to provide a comprehensive contribution to the knowledge of this natural material, from a multidisciplinary point of view, by experimentally assessing at both micro and macro scales, specific heat, thermal conductance, thermal conductivity, and sound reduction index. Results show the specific heat can vary from 1.4 to 1.9 J/gK, according to the given temperature and the investigated corn cob layers, while density is around 200 kg/m(3) and the conductivity, according to the investigated configurations, ranges from 0.14 to 0.26 W/mK. This work suggests a strategy to adopt for the evaluation of natural materials for building construction applications
PROGETTO INVOLUCRO: TRASMISSIONE LATERALE ATTRAVERSO GIUNTI IN CLT E GIUNTI MISTI MURATURA-CLT
Full text linkIl progetto Involucro è un progetto di ricerca finanziato dalla Regione Emilia-Romagna nell’ambito del POR-FESR 2014-2020 ed ha lo scopo di ottenere un sistema di facciata ventilata ad alte prestazioni termiche ed acustiche attraverso un’indagine sperimentale in condizioni reali, provando diverse soluzioni innovative. In questo articolo verranno mostrati i primi risultati della campagna di misure di trasmissione laterale condotta sulla struttura degli edifici test realizzati per il progetto
Direct and flanking transmission in CLT buildings: On site measurements, laboratory measurements and standards
Full text linkIDENTIFICAZIONE DELLA TRANSIZIONE DA CAMPO MODALE A DIFFUSO NEI PANNELLI IN XLAM
No full textLa modellazione dell’isolamento acustico di una partizione con i modelli SEA, adottati nelle ISO 12354, ha fra le ipotesi la diffusione del campo di vibrazione nell’elemento in esame. Per quanto riguarda i pannelli in XLAM, quest’ipotesi è senz’altro una delle più stringenti e non sempre verificate nelle frequenze utilizzate per la modellazione. Il presente lavoro riguarda quindi lo studio della transizione fra regime modale e regime diffuso negli elementi in XLAM attraverso il confronto fra misure sperimentali e modelli analitici
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