Analysis of the Influence of Thickness and Density on Acoustic Absorption of Materials Made from Used Cigarette Butts.

The effects of the density and thickness of samples made from used cigarette butts on acoustic characteristics were analyzed in this study. All the analyzed samples showed high acoustic performance, indicating that the fabrication of acoustic absorbing material may be a good use for this problematic waste (due to its toxicity, continuous generation, lack of recycling method, etc.).

Initial Conditioning of Used Cigarette Filters for Their Recycling as Acoustical Absorber Materials.

Used cigarette butts represent a major and problematic form of waste, due to their abundance, toxicity, and durability. Moreover, the few proposals for their recycling are clearly insufficient, and new ones are welcome. For a new proposal regarding the reuse of used cigarette butts as acoustical absorbers in building construction, previous conditioning of the used butts is performed.

Variability of traffic noise pollution levels as a function of city size variables.

Noise levels measured in 27 cities with different areas (from 0.6 km to 59.27 km) and populations (from approximately 2000 to 70,000 inhabitants) were compared with respect to five different urban characteristics (population, area, total street length, density, and linear density).

A proposal for producing calculated noise mapping defining the sound power levels of roads by street stratification.

The European Noise Directive proposes using strategic noise maps as tools to assess populations affected by environmental noise. It recommends using computational methods instead of in situ measurements when possible. A sound source's emission power is an important factor in the calculation of noise indicators.

Variability and Performance Study of the Sound Absorption of Used Cigarette Butts.

There has been increasing interest in new sustainable materials that can be used as construction materials. Among them, sound-absorbing materials have an important role in both acoustical room conditioning and in room insulation. As a proposal for recycling, one of the most common residues in the world, cigarette butts, is studied.

Analyzing nocturnal noise stratification.

Pollution associated to traffic can be considered as one of the most relevant pollution sources in our cities; noise is one of the major components of traffic pollution; thus, efforts are necessary to search adequate noise assessment methods and low pollution city designs. Different methods have been proposed for the evaluation of noise in cities, including the categorization method, which is based on the functionality concept. Until now, this method has only been studied (with encouraging results) for short-term, diurnal measurements, but nocturnal noise presents a behavior clearly different on respect to the diurnal one.

Urban streets functionality as a tool for urban pollution management.

Pollution derived from traffic can be considered one of the major problems of modern cities. Although considerable efforts have been devoted to gathering information about pollution and its control, little attention has been paid to the analysis of relationships between pollution distribution and town planning. The existence of these relationships would enable better prediction and prevention of pollution through town planning.

Possible relation of noise levels in streets to the population of the municipalities in which they are located.

A preview of the results of applying a categorization method to twenty towns with populations between 2200 and 700 000 inhabitants and areas between 0.57 km(2) and 59 km(2) is presented. This represents a significant expansion of the population size and area of urban sites studied by this method, with variations of two to three orders of magnitude, including the fourth most populous town in Spain.

A categorization method applied to the study of urban road traffic noise.

The present work summarizes a study of the hypothesis that urban noise can be stratified by measuring street noise according to a prior classification of a town's streets according to their use in communicating the different zones of the town. The method was applied to five medium-sized Spanish towns (Vitoria-Gasteiz, Salamanca, Badajoz, Cáceres, and Mérida) with populations ranging from 218 000 down to 50000 and with different socio-economic characteristics, climate, etc. As the initial hypothesis of the work was that traffic is the main source of urban noise and is also the principal cause of the variability of the sound levels measured in urban settings, the study focused only on the five nonpedestrian categories of streets.