Method to determine the speed of vehicles by means of noise levels variation

Statistical Pass-By Index is a parameter defined on ISO 11819-1: 1997, that pretends to measure the influence of road surfaces on traffic noise. One of the base parameters of this index is speed of vehicles on the road. The present paper shows a method to determine the speed of vehicles on the road using the shape of noise levels variations, and shows the improvement that this method can give one the selection of most correct pass-by levels

More than one insertion loss, throughout the day, for the same outdoor noise barrier

ISO 10847:1997 establishes a method for determining the insertion loss of noise barriers, assuming the existence of only one insertion loss for the same outdoor noise barrier. Since during the day distinct vertical gradients of sound speed may occur, different curved path radius of the sound rays can be formed, which leads to a different insertion loss throughout the day, for the same noise barrier. This article examines the influence of atmospheric conditions on the insertion loss of noise barriers and suggests how to complement the ISO 10847:1997

Variability of noise levels from railways

The purpose of this study is to determine the variability of noise levels associated with the pass-by of the same type of train at a point, near a railway, and compare this variability with the standard uncertainty, due to the operation of the source, established in ISO 1996-2: 2007, and in the document "Determination of Lden and Lnigth Using Measurements: 2006", from the European Work Group IMAGINE. With these results we can know the measurement effort required to achieve a certain standard uncertainty

Fast determination of the acoustic area of influence of roads, railways, airports and industries

It is very important to know, as early as possible, what is the acoustic area of influence of a particular project, because this information has influence in other areas, e.g. The extension of cartography necessary. So, it is relevant to find fast and simple methods to determine the acoustic area of influence, based on European Interim Methods, for roads, railways, airports and industries

Implantation of noise barriers in portuguese landscape

Noise makes part of the environment that we live in, and has a great impact on the perception of character and quality of landscape. By creating noise barriers, some people may concentrate on the negative impact that barriers have on the landscape due to their scale, appearance or other undesirable qualities, the noise itself may well have an unfavorable effect on the people's enjoyment of the landscape and can have, therefore, an adverse effect on landscape quality, landscape character and the quality of life. The purpose of this study is to give examples of some existing noise barriers in Portugal and to analyze how successfully, besides creating conditions for better acoustic comfort, they fulfill the conditions of an integration within the environment, by its composition and aesthetics solutions

Performing railway traffic vibration forecast using in situ vibration measurements

As international normalized methods for performing railway traffic vibration prediction are not available yet, the authors of this paper will analyze the feasibility and applicability of an in situ vibration measurement method in accordance with the guidelines establish in ISO 14837-1. The authors will present the achieved results of several vibration measurements, performed near the railways and the related transfer functions that will allow predicting the vibrations near different receiver locations

Air quality inside a school building: air exchange monitoring, evolution of carbon dioxide and assessment of ventilation strategies

This paper presents an assessment of indoor air quality and various ventilation strategies inside a school building located in the south of Portugal. In the first phase, ventilation rate was experimentally evaluated using the tracer gas method. In the second part, different airflow typologies were investigated and, after calculating the air exchange and flow rates for each of them, the evolution of metabolic carbon dioxide inside the spaces was numerically estimated. Ventilation measurements were made in classrooms, auditorium, offices, staff and computer rooms. The assessment of ventilation was based on evaluating the carbon dioxide produced by the occupants for three ventilation approaches; these were: one based on cross-flow natural ventilation (in current use) and two based on forced ventilation systems. In the case of the forced systems, one was based on providing a constant flow to meet the required Portuguese ventilation standard in the main occupied rooms while the other was an adjusted constant rate based on a simple calculation procedure that took into consideration the air quality needs of all the spaces including corridors and atria. This approach was developed to produce an efficient yet inexpensive ventilation approach that did not incorporate expensive sensors and control systems. Carbon dioxide evolution predictions were made using software that evaluated the thermal response and the air quality of a building with complex topology. The numerical model used to evaluate air quality, was based on mass conservation integral equations in which the final equations system was solved through the Runge-Kutta-Fehlberg method with error control. A statistical study of the occupation cycle in the school building during the day was developed

Heating, ventilating and air conditioning systems control based in the Predicted Mean Vote index

In this work a numerical model, which simulates the buildings thermal response and evaluates the indoor environment comfort, in transient conditions, is used in the application of Heating, Ventilating and Air Conditioning (HVAC) systems control, based in the Predicted Mean Vote (PMV) index, in the energy and thermal comfort performance in a kindergarten school building, in the South of Portugal, in Winter conditions. In the control the PMV index, based in the mean air temperature, the mean air velocity, the mean air relative humidity, the mean radiant temperature, the clothing level and the activity level, are used. In the numerical simulation of the kindergarten, the 25 compartments, the 498 building main bodies and the 42 windows glasses, as well as two schools and three residential surrounding main buildings, are considered

E-learning aplicado em CAD

Neste trabalho será apresentado uma nova metodologia utilizada em e-learning aplicada em CAD (Computing Aid Design), denominada por Desenho Assistido por Computador. Esta metodologia, que propicia o ensino e a aprendizagem a distância inclui igualmente a programação de script utilizados em desenho tridimensional mais avançado, permite o desenvolvimento de novas tecnologias, desde o projeto à impressão 3 D.Projeto (SAICT-ALG/39586/2018) financiado pelo Programa Operacional Regional do Algarve (CRESC Algarve 2020), ao abrigo do Acordo de Parceria Portugal 2020, através do Fundo Europeu de Desenvolvimento Regional (FEDER), e pela Fundação Nacional de Ciência e Tecnologia (FCT). [email protected]:eu-repo/semantics/publishedVersio

Application of an indoor greenhouse in the energy and thermal comfort performance in a kindergarten school building in the South of Portugal in winter conditions

In this work a numerical model, which simulates the buildings thermal response and evaluates the indoor environment comfort, in transient conditions, is used in the application of an indoor greenhouse in the energy and thermal comfort performance in a kindergarten school building, in the South of Portugal, in Winter conditions. In the numerical simulation of the kindergarten school building, the 25 compartments, the 498 building main bodies and the 42 windows glasses, as well as two schools and three residential surrounding main buildings, are considered. This numerical model is applied in the evaluation of the kindergarten thermal behavior, using the indoor temperature field, and the occupants thermal comfort levels, using the PMV and PPD indexes. After to be compared the numerical and experimental indoor air temperatures field and identified the indoor thermal uncomfortable spaces, the numerical model is used in the evaluation of the indoor greenhouse performance, in order to increase the indoor air temperature and thermal comfort levels, using solar renewable energy, without increase of the kindergarten energy consumption. It is analyzed in detail the greenhouse ventilation operating time and the warm airflow transport way, using an internal ducts system or a corridor space, from the greenhouse to the indoor coldest spaces