Acoustical comfort in university lecture halls: simulating the dynamic role of occupancy

The acoustic comfort in teaching environments is generally determined through requirements concerning reverberation time, speech intelligibility and HVAC noise. The presence of students reduces the reverberation time but concurrently increases the background noise, that undermines the focus of students and the vocal effort of teachers. A double set of measures were acquired in two university lecture halls in unoccupied and occupied state to investigate the consequences of occupancy variations. Acoustic simulations allowed to assess the dynamic effects of the occupancy detecting the differences of speech intelligibility. Predicting the student activity may return reliable outcomes improving the quality of lessons

Acoustic design of a multipurpose hall inside a former church

The present work is about an acoustic design for a former church converted into a multi-purpose auditorium. The current status of the hall has been classified by means of an acoustic measurements campaign complying with technical standards requirements. A numerical model, which has been calibrated through the measured values, led to the development of the acoustic design that includes sustainable and not-invasive interventions. In contrast with the practical habits, which would use a large amount of sound absorbing materials, an array of suspended reflecting panels over the musicians positions has been introduced. Exploiting the reflecting and scattering properties of those objects, sound clarity and speech definition improve. All the treatments are validated using numerical simulation softwares in order to estimate the efficiency of the whole improvement proposal

Safety and effectiveness of saving sphincter procedure in the treatment of chronic anal fissure in female patients

Lateral internal sphincterotomy (LIS) is still the approach of choice for the treatment of chronic anal fissure (CAF) regardless to the internal anal sphincter tone but it is burdened by high risk post-operative faecal incontinence (FI). In female patient there are some anatomical and functional differences of the sphinteric system which make them more at risk of FI and vaginal birth could cause sphinteric lesions affecting the anal continence function. The aim of our study is to evaluate the results of saving sphincter procedure as treatment for female patients affected by CAF

Characterization of an Arundo donax-based composite: A solution to improve indoor comfort

ABSTRACT: Arundo donax (giant reed or giant cane) is a widely available, perennial, invasive, non-food crop, present worldwide and employed for several uses, including building practices. Considering the increasing demand for sustainable building materials, A. donax can be an efficient solution. This study investigated its properties as a bio-aggregate mixed with a sodium silicate solution as an adhesive. A horizontal analysis that provided a general characterization of the composite was carried out. The results showed that the A. donax-based composite had an apparent density of 517 kg/m³, thermal conductivity of 0.128 W/(m.K), and high hygroscopicity, with a moisture buffering value of 4.33 g/(m² %RH), property that could be both an advantage for indoor comfort and a drawback. The uncommon sound absorption behaviour can be comparable to granular materials, with the highest sound absorption coefficient values, α, between 600 Hz and 700 Hz. Due to the range and the shape of the acoustic absorption property, this material may be helpful in acoustic treatments for speech noise. The mechanical tests defined flexural and compressive strength, respectively, 0.35 N/mm² and 0.9 N/mm², ensuring applicability. Above all, these tests opened new possible solutions for A. donax-based composite production either alone or in combination with other agro-industrial wastes and justified further tests, such as fire resistance and bio-susceptibility.info:eu-repo/semantics/publishedVersio

A feasible re-use of an agro-industrial by-product: Hazelnut shells as high-mass bio-aggregate in boards for indoor applications

The present work investigates the feasibility of producing boards, with unconventional materials, namely hazelnut shells as a high-mass bio-aggregate and a sodium silicate solution as a no-toxic adhesive, and discusses possible applications based on an extensive characterization. The aim is to define a feasible reuse of a largely produced agro-industrial by-product to reduce the high environmental impact caused by both the construction and the agriculture sectors, by proposing a building composite that improves indoor comfort. The presented combination of aggregate-adhesive generated a product with characteristics interesting to explore. The thermal conductivity is moderated, and the composite achieved values of σmax = 0.39 N/mm2 for flexural strength and σmax = 2.1 N/mm2 for compressive strength, but it showed high sorption capacity with a moisture buffering value of about 3.45 g/(m2 %RH), and a peak of sound absorption between 700 and 900 Hz. Therefore, the boards’ most promising performance parameters seem to be their high hygroscopicity and acoustic absorption behaviour, namely in the frequency range of the human voice. Hence, the proposed composite could improve indoor comfort if applied as an internal coating board

The coupled rooms of Odeo Cornaro (1534) as support for Renaissance musicians and soloists

The Odeo Cornaro in Padua (Italy) is a well-preserved XVI Century octangular music space (from Latin the ottangulo) surrounded by communicating smaller halls. Inspired by Roman classicism, the Renaissance architect Falconetto designed such coupled volume system for the private villa of the Venetian nobleman Alvise Cornaro. With the aim of assessing the acoustics of the Odeo by means of a contemporary approach, acoustic measurements were performed, and the room acoustic criteria were derived from the acquired impulse responses. Experimental results were employed to quantify the acoustic coupling effects throughout the environments and to outline the acoustic features of the central space. Numerical models were used to assess the free path distribution and the support given by the ottangulo to the singers’ voices. The main outcomes confirm the different use of the spaces suggested by historical research: while the main hall was probably employed for singing and playing instruments, the adjoining rooms were intended for erudite conversations and symposia. The symmetrical shape and the moderate volume of the central octangular space contribute to creating a neat modal behaviour that accentuates the sound propagation, highlighting the outstanding value of the Odeo as one of the “loci resonantes” of the past

A Matlab toolbox for the analysis of Ando’s factors

The autocorrelation and crosscorrelation functions analysis, as well-known in literature, allows to obtain remarkable results in different scientific fields. The autocorrelation function (ACF) and the interaural crosscorrelation function (IACF) analysis in architectural acoustics is known thanks to Y. Ando's work. The Toolbox presented in this work has been developed in order to compute Ando's significant and spatial factors (as the factors obtained from ACF and IACF are called), to subjective preference functions and to investigate further applications

The role of acoustic standards in the improvement of educational spaces in Italy

A good acoustics is one of the main requirements for indoor educational spaces, where information is transmitted from a teacher to students mainly by oral communication. Often obligatory regulations do not take into account this aspect as expected, but technical standards can provide a more informed and sound reference. In Italy, a new standard is under development at UNI (the national standardization body) to provide a technical framework for the design and use of teaching rooms in schools and a guideline has been released by AIA (Italian Acoustical Association) to provide a comprehensive, easy-to-read guide to authorities and stakeholders on the acoustical design of schools. The underlying principles and methods will be presented and discussed, as well as the way they are taught in University courses in order to raise awareness on these topics in future engineers and architects

Presenza femminile e carriere accademiche in Sapienza Università di Roma

The progressive reduction of the structured university staff and the increasing development of the scientific-technological disciplines with respect to the socio-humanistic ones can have different impacts on the presence of the two genders in the different academic contexts. From this point of view we analyze the gender characteristics of Sapienza University of Rome, the largest university in Europe, which represents about 7% of the Italian university system, continuing the general reflection started in a previous contribution (Baumgartner et al. 2015 ). Using the personal data of the staff currently in service, we are able to read the temporal evolution of gender equality, distinguishing it in two of the dimensions that characterize it: recruitment and career advancement. We evaluate the gender differences in career progression both with the well-known Glass-Ceiling Index (which measures the gender gap in access to positions of full professor) and by introducing another index, the Difference of Academic Position, which takes into account the differences in all career degrees. Furthermore, by introducing a simple theoretical model on career progressions, we propose temporal extrapolations on gender equality in Sapienza, also in relation to the various subject areas