Anna Magrini | University of Pavia (original) (raw)

Papers by Anna Magrini

Ancient worship buildings usually present articulated environments, such as lateral chapels, wher... more Ancient worship buildings usually present articulated environments, such as lateral chapels, where the effect of acoustic coupling rooms can influence the sound field. In the acoustically coupled rooms, reverberation times are fairly different from the ones measured without mutual power flow interactions through coupling areas. A preliminary investigation on the presence of coupling effects has been performed. Experimental values, measured in the lateral chapels of 3 Italian churches (XI-XVI sec) and in the corresponding coupled volumes of the selected environments, have been considered and compared with computed data given by a simple theoretical SEA (Statistical Energy Analysis) model. Application conditions and limitation of the model are discussed.

In Europe, the building sector accounts for 40% of energy consumption which has a strong influenc... more In Europe, the building sector accounts for 40% of energy consumption which has a strong influence on greenhouse gas emissions. The book deals with efficient methodologies aimed to reduce greenhouse gas emissions in the building sector. This includes analyses of the building envelopes, the heating systems, the use of solar energy, and the assessment of the environmental and energy sustainability of the proposed solutions. After a brief introduction to the physical fundamentals involved in the study, results are presented to support cost-effective technical strategies to promote actions for energy saving, in the most critical fields and with the most economic advantage.

Noise pollution caused by the activities in a race-track can affect wide spaces. First steps towa... more Noise pollution caused by the activities in a race-track can affect wide spaces. First steps towards a reduction of noise levels are afforded by the international sport organisations that admit only silenced super-bikes in the competitions and that have put further reduced noise emissions requirements starting from the end of 2007. An experimental analysis on a racing track approved for international racings was performed with the circulation of various kinds of racers. After the calibration by means of measured data, the software model simulations of various race conditions were analysed. The results were compared with the experimental monitoring performed by a recently developed system that permits to register and to send directly all the results to a remote server in real time. The analysis has highlighted on one side some situations of exceeding noise that can be detected only by a continuous monitoring, on the other side the conditions in which the track can be used without ove...

In the recent years, the improvement of buildings energy performance has received more and more a... more In the recent years, the improvement of buildings energy performance has received more and more attention. The acoustic aspects are still considered often in a separate context, even if the acoustic and thermal insulation strategies applied to building structures could lead to bet-ter results if considered jointly, as both are based on the correct combination of materials, building construction techniques and workmanship. The paper's objective is to highlight the advantages of the use of combined evaluation of thermal, hygrometric and acoustic behavior of existing building walls. The study highlights some aspects of the refurbishment actions, aiming to a more efficient integrated design of the acoustic and thermo-hygrometric perfor-mance. The analysis of the acoustic and thermo-hygrometric properties of some typical wall samples is developed on the one hand by means of acoustic measurements and, on the other hand, from walls thermo-hygrometric databases. The comparison with refe...

Energy and Buildings, 2014

ABSTRACT The article deals with the main problems arising during the sustainable renovation proce... more ABSTRACT The article deals with the main problems arising during the sustainable renovation process and energy refurbishment of historical architecture. In particular, it focuses on the feasibility study for a huge historical listed building, aiming at its progressive and complete re-utilization as university campus, respectful of the many cultural values of which it is the depository. The complex of the ‘Albergo dei Poveri’ was built in Genoa between the late seventeenth century and the middle of the nineteenth century, as a monumental structure for charitable purposes. Given its size and location in the heart of the city, it still represents an important urban structure and a great opportunity for urban renewal, even though it is actually almost completely abandoned. Main aim of the research is the definition, from a methodological and technical point of view, of feasibility studies in order to submit the historical monumental heritage to a process of ‘energy efficiency’ and ‘energy production’, even recurring to the most suitable technologies supplied by renewable energies. In this paper, a preliminiary approach and general criteria for the building refurbishment, in relation to the architectural and historical commitments, are presented.

Proceedings of Forum Acusticum

The results of the acoustic investigations carried out in two worship buildings, with the same ar... more The results of the acoustic investigations carried out in two worship buildings, with the same architectural structure, belonging to the same historical period, but restructured in a different way, are presented. Morimondo and Chiaravalle Abbeys are characterized by the sam e longitudinal plan, with one nave and two aisles. They were built in the respect of the principles of the Benedictine monastic order. Their indoor surfaces present a similar distribution of stone and bri cks. However some di fferences due to the internal volume distribution (presence of walls partially obstructing the connections between aisles and nave, chorus wooden walls located in a di fferent position in the nave, etc) and their influence on the acousti c fi eld in the two Churches can be highlighted. The reverberation time values in the two Churches have a similar slope as function of the frequency, while the absolute values for each octave band di ffer quite for hal f a second reverberation time. In Morimondo and Chiaravalle Abbeys the acoustic field results less reverberant than in other Churches of the same monastic order, previously studied: this effect can be adduced to the higher absorption coeffi cient of the walls that were built of bricks instead of stones as the other ones.

Nearly Zero Energy Building Refurbishment, 2013

ABSTRACT Regarding energy performance assessment of existing building, the European Standards EN ... more ABSTRACT Regarding energy performance assessment of existing building, the European Standards EN ISO 13790 and EN 15316, adopted at national level in Italy by Technical Standards UNI/TS 11300 (part 1 and 2), allow different approaches and simplification levels for defining some representative input parameters determining uncertainties in the results. Therefore, the reliability of calculated energy performance could be affected. The analysis has been supported applying a set of refurbishment actions on some representative cases of common national residential building stock, comparing the energy performance obtained with different calculation methods allowed by National Technical Standards and laws. The results show how these differences can lead to uncertainties about the class definition.

Indoor Air, 1996

ABSTRACT Abstract This paper reports on an investigation into the rates of isothermal vapour tran... more ABSTRACT Abstract This paper reports on an investigation into the rates of isothermal vapour transfer taking place between moist air and a hygroscopic solution through a hydrophobic synthetic membrane. The membrane acts as a porous barrier between the phases, being permeable to the vapour but not to the contacting liquid.Experimental results, obtained for a polyethylene membrane with a thickness of 170 μm, show that the total mass transfer coefficient between moist air and a saturated LiCl solution is of the order of 0.078 g/m2hPa at 21°C, at least when the air phase moves at a velocity ranging from 1.5 to 3 m/s. The vapour transfer rate through the membrane is essentially controlled by the convective resistance to vapour transport on the air side and by the resistance to mass transport offered by the membrane. The vapour flux exchanged between the moist air and the hygroscopic solution, although limited by the membrane, appears to be sufficiently high to make the use of vapour membrane exchangers technically feasible in air dehumidification and conditioning.

intellagence.eu.com

The acoustic characterisation of buildings for music performances involves not only theatres, but... more The acoustic characterisation of buildings for music performances involves not only theatres, but also worship buildings, that with adequate acoustic quality, could held musical performances although temporarily. In order to complete previous analyses, focus ed on Churches with rect angular plans and two aisles, also cent ral plan Churches were investigated. Considerations on experimental values of the mai n acoustic paramet ers obtained in a considerabl e number of Churches are here presented. Measurement results were compared with acoustic data available in literature regarding theat res and auditoriums. The examined Churches are cl assifi ed in agreement with the optimal values of the acoustical parameters for the listening of music. Moreover the spatial distribution of the acoustical parameters, as a function of the source -receiver distance, is evaluated. It is then correl ated to the presence of architectural elements, such as lateral chapels, dome, vaults and columns.

Energy and Buildings, 1997

... PI=| GI APID JUILDIPIGS On the application of a membrane air-liquid contactor for air dehumid... more ... PI=| GI APID JUILDIPIGS On the application of a membrane air-liquid contactor for air dehumidification Carlo Isetti a, Enrico Nannei b Anna Magrini a ... ( 1 ) becomes: g~ =Mwkl(ct/yw) (a~ - aw&#x27;) (6) where the k~ coefficient can be obtained by means of the Chilton-Colburn analogy ...

Research for Development, 2014

Applied Energy, 2012

... Anna Magrini,; Lorenza Magnani,; Roberta Pernetti Corresponding author contact information , ... more ... Anna Magrini,; Lorenza Magnani,; Roberta Pernetti Corresponding author contact information , E-mail the corresponding author. University of Pavia, Department of Environmental and Hydraulic Engineering, Via Ferrata 1, 27100 Pavia, PV, Italy. Received 26 July 2011. ...

1. Introduzione Lo studio analizza e valuta il processo realizzativo degli interventi di bonifica... more 1. Introduzione Lo studio analizza e valuta il processo realizzativo degli interventi di bonifica acustica di facciate di edifici residenziali siti nelle vicinanze dell'aeroporto di Bergamo-Orio al Serio, seguendo tutte le sue fasi comprendenti, in particolare, l'individuazione delle abitazioni necessitanti di bonifica, la definizione degli interventi da porre in essere e la realizzazione dei collaudi sul campo a seguito dell'esecuzione dei lavori definiti. I criteri individuati a seguito degli studi effettuati su questo particolare caso di lavoro risultano applicabili anche in altri contesti simili, caratterizzati dalle stesse esigenze di miglioramento delle prestazioni acustiche degli edifici, dallo stesso contesto ambientale (aree nelle vicinanze di infrastrutture di trasporto aeroporti, strade a scorrimento veloce e ferrovie) e dalle stesse regolamentazioni legislative. 2. Metodo di studio L'individuazione delle abitazioni oggetto di bonifica è stata effettuata s...

pcfarina.eng.unipr.it

Il patrimonio architettonico storico Italiano è ricco di edifici destinati alla musica ed in part... more Il patrimonio architettonico storico Italiano è ricco di edifici destinati alla musica ed in particolare di teatri d'opera. Nel passato questi hanno rappresentato un punto fondamentale di aggregazione contribuendo a diffondere la cultura musicale nei confronti di un ampio pubblico. La rappresentazione dell'opera agli inizi del seicento stimolò la modifica e la costruzione di teatri idonei allo scopo, sia in Italia sia all'estero. La pianta a forma di ferro di cavallo, quella ellittica, quella circolare, con i palchi sulle pareti, rappresentarono forme ...

1. Introduzione La possibilità di utilizzare metodi di simulazione per prevedere il comportamento... more 1. Introduzione La possibilità di utilizzare metodi di simulazione per prevedere il comportamento acustico di una sala rappresenta un elemento indispensabile nella progettazione e nell'analisi acustica. Tuttavia potrebbe essere interessante in fase di valutazioni prelimi-nari, la possibilità di utilizzare espressioni semplificate che permettano analisi appros-simative non solo per il calcolo del tempo di riverberazione ma anche degli altri para-metri acustici significativi. In alcuni casi la modellizzazione dell'ambiente per una valu-tazione mediante software potrebbe essere onerosa a fronte delle esigenze e degli obiet-tivi da raggiungere. Inoltre, per prevedere l'effetto di interventi temporanei che portino a variazioni delle condizioni acustiche di una sala, potrebbe essere efficace in prima approssimazione uti-lizzare un approccio semplificato: prime ipotesi su materiali e superfici potenzialmente utilizzabili o sulla collocazione delle sorgenti potrebbero essere sup...