Design, Manufacturing and Acoustic Assessment of Polymer Mouthpieces for Trombones.

Brass instruments mouthpieces have been historically built using metal materials, usually brass. With the auge of additive manufacturing technologies new possibilities have arisen, both for testing alternative designs and for using new materials. This work assesses the use of polymers for manufacturing trombone mouthpieces, specifically PLA and Nylon.

The Environmental Impacts of Disposable Nonwoven Fabrics during the COVID-19 Pandemic: Case Study on the Francesc de Borja Hospital.

Hospitals generate huge amounts of nonwoven residues daily. This paper focused on studying the evolution of nonwoven waste generated in the Francesc de Borja Hospital, Spain, over the last few years and its relation to the COVID-19 pandemic. The main objective was to identify the most impacting pieces of nonwoven equipment in the hospital and to analyze possible solutions.

Life-Cycle Assessment and Acoustic Simulation of Drywall Building Partitions with Bio-Based Materials.

The ecological transition is a process the building industry is bound to undertake. This study aimed to develop new bio-based building partition typologies and to determine if they are suitable ecological alternatives to the conventional non-renewable ones used today. This work started with the development of a bio-based epoxy composite board and a waste-based sheep wool acoustic absorbent.

Sound Absorption Properties of Perforated Recycled Polyurethane Foams Reinforced with Woven Fabric.

The acoustic properties of recycled polyurethane foams are well known. Such foams are used as a part of acoustic solutions in different fields such as building or transport. This paper aims to seek improvements in the sound absorption of these recycled foams when they are combined with fabrics.

Characterization of Sheep Wool as a Sustainable Material for Acoustic Applications.

In recent years, natural materials are becoming a valid alternative to traditional sound absorbers due to reduced production costs and environmental protection. This paper reports the acoustical characterization of sheep wool. Measurements on normal incidence and diffuse-incidence sound absorption coefficients of different samples are reported.

Effect of Sodium Hydroxide Treatments on the Tensile Strength and the Interphase Quality of Hemp Core Fiber-Reinforced Polypropylene Composites.

The formulation of greener composite materials by substituting glass fibers with natural fibers is a current field of research. If such natural fiber reinforcements come from industrial side streams, as hemp core fibers (HCFs) come from the extraction of hemp strands for the textile industry, an additional advantage can be identified. Nonetheless, such by-product fibers show some drawbacks, such as high lignin contents, which can make it difficult to obtain a good interphase between the fibers and the matrix and to obtain a good fiber individualization.

Vibroacoustic Impact on the Architectonic Heritage When Using Replicas of 16th Century Weapons.

The recreation of historical battles next to old buildings, walls, churches, fortifications or historical facades belonging to the historical heritage of a city, has always been a source of controversy and discussion. In the absence of a clear legislation about how these buildings can be affected by the use of blunderbusses and pyrotechnics, it is necessary to carry out practical experiments to test the effect of these celebrations on these buildings. For this reason, this paper presents a set of practical experiments where the vibroacoustic effect of using weapons such as blunderbusses and harquebuses is analyzed.