Odor problems are a common complaint from residents living near landfills. Many compounds can cause malodorous conditions. However, hydrogen sulfide (h2s) has been identified as a principal odorous component from construction and demolition (c&d)debris landfills. Although several studies have reported the ambient concentrations of h2s near c&d landfills, few studies have quantified emission rates of h2s. The most widely used and proven technique for measuring gas emission rates from landfills is the flux chamber method. Typically the flux chamber is a cylindrical enclosure device with a spherical top which limits the gas emission area. Pure zero grade air is introduced into the chamber, allowed to mix with emitting gases captured from the landfill surface, and then transported to the exit port where concentrations can be measured. Flux measurements using the flux chamber were performed at five different c&d landfills from june to august, 2003. The flux rates of h2s measured in this research were three to six orders of magnitude lower than the flux rates of methane reported in the literature. In addition to the h2s flux measurements, dispersion modeling was conducted, using the epa dispersion model, industrial source complex short term (iscst3), in order to evaluate impacts on landfill workers and communities around the landfills. The modeling results were analyzed to estimate the potential ground level maximum h2s concentrations for 1-hr and 3-min periods and the frequency (occurrences per year) above the h2s odor detection threshold for each landfill. Odor complaints could be expected from four among five landfills selected for this study, based on 0.5-ppb odor detection threshold.

Note:

No description available.

In this study eddy covariance was used to measure sensible heat, latent heat, and carbon dioxide fluxes for the months of August, September, and October of 2009 within the roughness sublayer (RSL) of the urban center of Portland, OR. Vehicle traffic and solar radiation were also measured for the month of October. Flux measurements were compared with measurements from other urban areas as a test of reasonableness. CO₂ fluxes were nearly always positive and were strongly correlated with the weekday diurnal traffic cycle. CO₂ fluxes averaged 6.6 μmol/m^²s, which is less than other published measurements in urban areas. Sensible and latent heat fluxes followed the expected diurnal profile associated with solar radiation. Average sensible heat flux decreased as the season changed from summer to fall, moving from an average of 39 W/m^² in August to 12 W/m^² in October. A corresponding increase in latent heat flux was observed during this period, changing from an average of 10 W/m^² in August to 17 W/m^² in October. Heat flux behavior and amplitude was consistent with other urban measurements, though amplitude varies considerably from city to city. Stationarity was shown to positively influence measured CO₂ fluxes, but to have little effect on measured heat fluxes. Preliminary comparisons of October sensible heat and CO₂ fluxes to an inventory-based estimate of vehicle emissions indicate that eddy covariance measurements underestimate the true fluxes by 50%.

No description available.

Dans le cadre de la recherche de solutions visant à réduire les consommations d’énergie liées au rafraîchissement des bâtiments, une plateforme d’essais a été mise en place en 2012 à l’I2M et installée sur le site de l’IUT de l’Université de Bordeaux. Cette plateforme est issue d’un prototype de bâtiment BEPos, dénommée Sumbiosi, réalisée par un consortium rassemblé autour du campus de Bordeaux dans le cadre de sa participation à la compétition interuniversitaire du Solar Decathlon Europe 2012. Elle a notamment été conçue de façon à favoriser le stockage passif d’énergie diurne en hiver et le déstockage semi-passif d’énergie nocturne en été. Deux éléments principaux permettent a priori ces fonctions de stockage et déstockage passifs d’énergie : une dalle de forte masse thermique située du côté de la façade Sud vitrée du bâtiment, et des protections solaires et ouvertures pilotables sur les façades Sud, Nord et en lanterneau du bâtiment ; ces dernières assurent les trois principes fondamentaux en ventilation naturelle qui ont lieu grâce aux effets du tirage thermique et de la force du vent. L’objet des travaux menés actuellement ont pour objectif initial d’appréhender qualitativement le stockage-déstockage d’énergie dans la dalle, celle-ci étant soumise à des échanges radiatifs (extérieur et d’intérieur) et convectifs (générés par convection naturelle, forcée ou mixte). Ils visent par la suite à caractériser précisément et quantitativement le couplage entre ce stockage-déstockage, et les circulations d’air et apports radiatifs constatés. La mise en place d’une modélisation, reliant l’ensemble de ces paramètres est envisagée, dans le but d’avancer vers une loi de pilotage de ces éléments mobiles amenant à des conditions de confort internes au bâtiment optimales. Cette dernière doit nous permettre de montrer qu’un choix adéquat de stratégie de ventilation permet une minimisation de consommations électrique en évitant autant que possible le recours à la climatisation. Pour atteindre cet objectif, la démarche scientifique adoptée a consisté à mettre en évidence le rôle de la dalle en béton dans stockage/déstockage d’énergie thermique, sous l’effet de différents scénarii de ventilation naturelle de la plateforme. Cette dalle a été instrumentée, de façon discrète sur l’ensemble de sa surface, en termes de capteurs de flux de chaleur (Peltier et Captec), de températures (thermocouples T), et de la vitesse d’air proche de la dalle. Les premiers résultats, obtenus en période estivale, mettent clairement en évidence le couplage entre les phénomènes de stockage et déstockage d’énergie quotidiens et le cycle météorologique correspondant, ceci pour divers scénarii de pilotage des éléments mobiles de l’enveloppe du bâtiment (persiennes, ouvertures). / As part of the search for solutions to reduce the energy consumption related to the refreshment of buildings, a test platform was set up in 2012 at the I2M and installed on the IUT site of the " University of Bordeaux. This platform is the result of a prototype of a PEHs building called Sumbiosi, carried out by a consortium gathered around the Bordeaux campus as part of its participation in the inter-university competition of the Solar Decathlon Europe 2012. It was conceived in such a way as to favor the passive storage of diurnal energy in winter and the semi-passive destocking of nighttime energy in summer. Two main elements allow a priori these functions of passive storage and retrieval of energy: a slab of high thermal mass located on the side of the glazed south facade of the building, and solar protections and openings controllable on the facades South, North and skylight of the building ; the latter provide the three fundamental principles of natural ventilation, which take place through the effects of thermal draft and wind force. The object of the work currently carried out has the initial objective of qualitatively understanding the storage and de-stocking of energy in the slab, the latter being subjected to radiative (external and internal) and convective exchanges (generated by natural convection, forced or mixed). They are intended to characterize precisely and quantitatively the coupling between this storage and release, and the circulations of air and radiative contributions observed. The implementation of a modeling, linking all these parameters is envisaged, with the aim of advancing towards a law controlling these mobile elements leading to optimum internal comfort conditions for building. The latter must enable us to show that an adequate choice of ventilation strategy allows a minimization of electrical consumption by avoiding the use of air conditioning as much as possible. To achieve this objective, the scientific approach adopted consisted in highlighting the role of the concrete slab in the storage / destocking of thermal energy, under the effect of different scenarios of natural ventilation of the platform. This slab was instrumented, discretely over its entire surface, in terms of heat flux sensors (Peltier and Captec), temperatures (T thermocouples), and air speed close to the slab. The first results, obtained during the summer period, clearly show the coupling between the phenomena of daily energy storage and destocking and the corresponding meteorological cycle for various scenarios controlling the moving elements of the building envelope (shutters, openings).