49 research outputs found
Nuevos datos sobre la estructura general del Carbonífero en el Horst de La Camocha (Gijón, Asturias).
Una reciente campaña de investigación geológico-minera, mediante la realización de transversales de reconocimiento, sondeos de superficie e interior y perfiles sísmicos de reflexión, ha permitido profundizar en el conocimiento de la estructura del Carbonífero en el entorno de Mina La Camocha. En esta zona, al sur de Gijón, los materiales carboníferos, cubiertos por una cobertera permotriásica y jurásica, no afloran. Se precisa el estilo de plegamiento, analizándose y datándose las principales familias de fracturación. El estilo tectónico de los materiales carboníferos productivos no aflorantes, se ilustra mediante varios de los nuevos cortes obtenidos
Caracterización de los parámetros hidráulicos de la cobertera pérmica en el Horst del yacimiento carbonífero de Mina «La Camocha».
En la cobertera pérmica existente sobre el yacimiento carbonífero actualmente en explotación por Mina La Camocha, S. A., se localiza un acuífero multicapa con varios niveles claramente diferenciados. Por medio de diversas técnicas de estudio, se ha tratado de determinar los parámetros hidráulicos de estos materiales en varias localidades próximas a Gijón, con el fin de elaborar un esquema de funcionamiento hidráulico y estimar la posible influencia de este acuífero en las labores de explotación
Effect of waste materials on acoustical properties of semi-dense asphalt mixtures
Among the urban societal burdens rolling noise generation from tire pavement interaction and urban waste stand apart. Many urban waste materials can be used in pavements with comparable mechanical performance. Noise-related pavement characteristics such as porosity, sound absorption and surface texture, were measured for semi-dense low noise pavement mixtures using urban waste materials namely: recycled concrete aggregates, crumb rubber, polyethylene terephthalate and polyethylene. The results show that the use of these materials is a viable sustainable option for low noise pavements, however that may affect the noise reduction properties. With values around 0.2 at 1000 Hz, the sound absorption of all the mixtures is relatively low and the use of mean profile depth (MPD) alone is not enough to characterize the noise reduction properties. Surface texture was altered in different degrees depending on the waste material used. The results presented can aid in policy pertaining to noise abatement and waste reduction
A survey on exposure-response relationships for road, rail, and aircraft noise annoyance: differences between continuous and intermittent noise
The aim of the present study is to establish exposure-response relationships reflecting the percentage highly annoyed (%HA) as functions of road traffic, railway, and aircraft noise exposure, measured as day-evening-night level (Lden), as well as to elucidate the degree to which the acoustic indicator Intermittency Ratio (IR), which reflects the "eventfulness" of a noise situation, predicts noise annoyance. We conducted a mixed-mode representative population survey in a stratified random sample of 5592 residents exposed to transportation noise all over Switzerland. Source-specific noise exposure was calculated for each floor and each façade based on comprehensive traffic data. Noise annoyance was measured using the ICBEN 11-point scale. The survey was carried out in 4 waves at different times of the year. We hypothesized that in addition to Lden, the effects of noise on annoyance can be better explained when also considering the intensity of short-term variations of noise level over time. We therefore incorporated the acoustic indicator IR in the statistical models. For all noise sources, results revealed significant associations between Lden and %HA after controlling for confounders and independent predictors such as IR (measured over 24 h), exposure to other transportation noise sources, sex and age, language, home ownership, education level, living duration, temperature, and access to a quiet side of the dwelling. Aircraft noise annoyance scored markedly higher than annoyance to railway and road traffic noise at the same Lden level. Railway noise elicited higher percentages of highly annoyed persons than road traffic noise. Results furthermore suggest that for road traffic noise, IR has an additional effect on %HA and can explain shifts of the exposure-response curve of up to about 6 dB between low IR and high IR exposure situations, possibly due to the effect of different durations of noise-free intervals between events. For railway and aircraft noise annoyance, the predictive value of IR was limited
Las sucesiones estratigráficas del Paleozoico Inferior y Medio
p. 31-43Ya se ha visto que la formación del Macizo Ibérico,
donde aflora el basamento de la Península Ibérica, está
íntimamente ligada al desarrollo de la orogenia Varisca
del Paleozoico Superior. La consecuencia fue el acortamiento
y deformación intensa de los sedimentos marinos
depositados previamente a lo largo de los extensos
márgenes continentales de Gondwana durante el
Paleozoico Inferior y Medio. El Macizo Ibérico contiene
los afloramientos más extensos y fosilíferos de cuantos
componen la Cadena Varisca europea. Sus distintas zonas
estructurales y paleogeográficas albergan importantes
sucesiones estratigráficas de los períodos
Cámbrico a Devónico (García-Cortés et al., 2000,
2001; Gutiérrez-Marco, 2006), que configuran uno de
los contextos geológicos clave para conocer la evolución
fini-precámbrica y paleozoica de la Península
Ibérica y de Europa Occidental, y en donde se registran
numerosos eventos geológicos y biológicos de alcance
global
Episodios sedimentarios en el Alcudiense Superior (Proterozoico) y su tránsito al Cámbrico en la zona centro meridional del Macizo Ibérico
The evolution of the Upper Alcudian-Lower Cambrian basin is studied in the eastern lusitanian-Alcudian Zone. Five sedimentary episodes with distinctive characteristics are considered
Sequential Analysis of Trans-SNARE Formation in Intracellular Membrane Fusion
SM proteins stabilize cis-SNARE complexes leading to a specific preferred topology for trans-SNARE formation
Noise exposure-response relationships established from repeated binary observations: Modeling approaches and applications
Noise exposure-response relationships are used to estimate the effects of noise on individuals or a
population. Such relationships may be derived from independent or repeated binary observations,
and modeled by different statistical methods. Depending on the method by which they were established,
their application in population risk assessment or estimation of individual responses may
yield different results, i.e., predict “weaker” or “stronger” effects. As far as the present body of literature
on noise effect studies is concerned, however, the underlying statistical methodology to
establish exposure-response relationships has not always been paid sufficient attention. This paper
gives an overview on two statistical approaches (subject-specific and population-averaged logistic
regression analysis) to establish noise exposure-response relationships from repeated binary observations,
and their appropriate applications. The considerations are illustrated with data from three
noise effect studies, estimating also the magnitude of differences in results when applying
exposure-response relationships derived from the two statistical approaches. Depending on the
underlying data set and the probability range of the binary variable it covers, the two approaches
yield similar to very different results. The adequate choice of a specific statistical approach and its
application in subsequent studies, both depending on the research question, are therefore crucial
An event-related examination of awakenings due to nocturnal church bell sounds
We carried out a a field study to elucidate whether acoustic properties of nightly
church bell ringing events systematically relate to awakening reactions. Results indicate
that the bell ringing events increase awakenings in a similar fashion as has pr eviously
been reported with transportation noise events (aircraft, railways) and that
awakening probability first and foremost depends on maximum sound pressure level
of an event