1,721,462 research outputs found
Survey on the acoustical properties of new sustainable materials for noise control
No full textAccording to the definition of sustainability (Sustainable
development meets the needs of the present without
compromising the ability of future generations to meet their
own needs ), a product can be considered sustainable if its
production enables the resources from which it was made
to continue to be available for future generations. A
sustainable product can thus be created repeatedly without
generating negative environmental effects, without causing
waste-products to accumulate as pollution, and without
compromising the wellbeing of workers or communities.
In the last years many new materials for noise control have
been studied and developed as alternatives to the
traditional ones (glass or rock wool); these materials are
either natural (cotton, cellulose, hemp, wool, clay, etc) or
recycled (rubber, plastic, carpet, cork, etc.). Various
methodologies have been proposed to evaluate the
sustainability of materials and products (LCA,
ECOINVENT; ECOPROFILES).
The paper presents an updated survey of acoustical
properties of sustainable materials and in particular sound
absorption coefficient, airborne and impact sound
insulation data, as well as an analysis of the procedures to
asses the sustainability of these materials.
Several sustainable materials have also been tested by the
Author at the Acoustic laboratory of the University of
Perugia: among these expanded clay granulates, kenaf,
recycled polyester panels, re-cycled plastic, absorbing
foams obtained from urban waste. Researches in this field
received a boost thanks to the collaboration with the
University of Bradford (UK): sustainable acoustic materials,
especially from used tyres and carpets, were produced
with good properties as far as impact sound insulation. The
paper presents and discusses all the experimental data
and draws come considerations and conclusions on future
perspectives for sustainable materials for noise control
Criteri per l’esecuzione dei piani di contenimento ed abbattimento del rumore prodotto dalle infrastrutture ferroviarie
No full textMosaico Romano di Orfeo a Perugia: indagini ambientali e progetto di massima per un intervento conservativo
No full textIl lavoro presenta i risultati di un esteso monitoraggio ambientale, volto ad individuare le cause di degrado del Mosaico Romano di Orfeo, situato a Perugia nell'atrio del Dipartimento di Chimica. Il Mosaico è un importante reperto archeologico del II sec. d.c., raffigurante il mito di Orfeo che incanta gli animali con il suono della lira; in virtù della sua ubicazione è purtroppo sottoposto a condizioni ambientali non ottimali e versa in cattive condizioni di conservazione. Le indagini eseguite (misure di temperatura e umidità relativa dell'aria, misure di temperatura superficiale, di illuminamento, di irraggiamento, indagini geofisiche) hanno consentito di individuare con precisione le cause di degrado e di formulare una articolata proposta per un intervento conservativo
Tesi di Dottorato di Ricerca "Misure di tensione di vapore e di densità di nuovi fluidi per un possibile impiego in macchine ad assorbimento"
No full textLinee-guida per la realizzazione di impianti di termovalorizzazione di RSU, ecologicamente compatibili
No full textCriteri per l’esecuzione dei piani di contenimento ed abbattimento del rumore prodotto dalle infrastrutture ferroviarie
No full textSound absorption properties of loose expanded clay of various granulometries
No full textThe latest Italian laws on acoustic pollution (Law n. 447/95 and relative directives) have focused attention on the acoustic performance of construction materials; in this field the use of expanded clay products is particularly indicated for their sound absorption and insulating properties.
Expanded clay is a truly versatile material and used extensively in construction, e.g. lightened concrete for floors and coverings and production of thermal blocks for walls and roofs; these products have recently been used also in the field of transport to build sound absorbing asphalts and acoustic barriers. 1,2.
Loose expanded clay is used also in coating blast furnace chimneys.
The Department of Industrial Engineering of the University of Perugia has carried out a study in the past years for ANPAE (National Association of Manufacturers of Expanded Clay) on the acoustic properties of expanded clay products and manufactured items.3. This paper illustrates the measurement results of the absorption coefficient of loose expanded clay for different granulometries and manufacturers.
The measurements taken at the Acoustic Laboratory of the University of Perugia show how expanded clay has good acoustic absorption properties (a> 0.7) in a wide frequency range (300-2000 Hz).The experimental results were then compared with values calculated with a calculation model, suitably calibrated for this use. The comparison showed a good correlation
Daylighting performance of sawtooth roofs for industrial buildings
No full textNatural lighting in industrial, commercial and sports buildings is usually provided by roofs with transparent surfaces. Sawtooth roofings, in which opaque modular elements are combined with transparent surfaces, whether inclined or in various shapes, are especially popular. The exact dimensioning of these roofs is extremely important both in terms of energy savings (less electricity needed for artificial lighting) and as regards vision quality.
The paper illustrates a calculation method that accurately assesses daylighting performances of sawtooth roofs. The method allows detailed modelling of the sawtooth’s shape to be created and the transmittances and reflectances of all the materials making up the roofs to be taken into account.
The calculation method was applied to eleven different sawtooth roofs supplied by different manufacturers; the results were compared and some technical solutions were suggested for optimizing the performances of the roofs analyzed.
Experimental verifications were performed on the method in two industrial buildings, with different roofs; the results show that the calculation method being proposed is both accurate and reliable
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