1000 resultados para RN-214
Resumo:
Natural analogs offer a valuable opportunity to investigate the long-term impacts associated with thepotential leakage in geological storage of CO2.Degassing of CO2and radon isotopes (222Rn?220Rn) from soil, gas vents and thermal water dischargeswas investigated in the natural analog of Campo de Calatrava Volcanic Field (CCVF; Central Spain) todetermine the CO2?Rn relationships and to assess the role of CO2as carrier gas for radon. Furthermore,radon measurements to discriminate between shallow and deep gas sources were evaluated under theperspective of their applicability in monitoring programs of carbon storage projects.CO2flux as high as 5000 g m?2d?1and222Rn activities up to 430 kBq m?3were measured;220Rn activi-ties were one order of magnitude lower than those of222Rn. The222Rn/220Rn ratios were used to constrainthe source of the Campo de Calatrava soil gases since a positive correlation between radon isotopic ratiosand CO2fluxes was observed. Thus, in agreement with previous studies, our results indicate a deepmantle-related origin of CO2for both free and soil gases, suggesting that carbon dioxide is an efficientcarrier for Rn. Furthermore, it was ascertained that the increase of222Rn in the soil gases was likely pro-duced by two main processes: (i) direct transport by a carrier gas, i.e., CO2and (ii) generation at shallowlevel due to the presence of relatively high concentrations of dissolved U and Ra in the thermal aquiferof Campo de Calatrava.The diffuse CO2soil flux and radon isotopic surveys carried out in the Campo de Calatrava VolcanicFields can also be applicable to geochemical monitoring programs in CCS (Carbon Capture and Storage)areas as these parameters are useful to: (i) constrain CO2leakages once detected and (ii) monitor both theevolution of the leakages and the effectiveness of subsequent remediation activities. These measurementscan also conveniently be used to detect diffuse leakages.
Resumo:
Hay un ejemplar encuadernado con: Breve descripcion de las fiestas que hizo el Real Convento de Predicadores de Valencia en la beatificacion del B. Juan de Ribera. Y sermón que predicó ... Luis Ballester, prior del mismo convento. (XVIII/4277).
Resumo:
For each pair (n, k) with 1 ≤ k < n, we construct a tight frame (ρλ : λ ∈ Λ) for L2 (Rn), which we call a frame of k-plane ridgelets. The intent is to efficiently represent functions that are smooth away from singularities along k-planes in Rn. We also develop tools to help decide whether k-plane ridgelets provide the desired efficient representation. We first construct a wavelet-like tight frame on the X-ray bundle χn,k—the fiber bundle having the Grassman manifold Gn,k of k-planes in Rn for base space, and for fibers the orthocomplements of those planes. This wavelet-like tight frame is the pushout to χn,k, via the smooth local coordinates of Gn,k, of an orthonormal basis of tensor Meyer wavelets on Euclidean space Rk(n−k) × Rn−k. We then use the X-ray isometry [Solmon, D. C. (1976) J. Math. Anal. Appl. 56, 61–83] to map this tight frame isometrically to a tight frame for L2(Rn)—the k-plane ridgelets. This construction makes analysis of a function f ∈ L2(Rn) by k-plane ridgelets identical to the analysis of the k-plane X-ray transform of f by an appropriate wavelet-like system for χn,k. As wavelets are typically effective at representing point singularities, it may be expected that these new systems will be effective at representing objects whose k-plane X-ray transform has a point singularity. Objects with discontinuities across hyperplanes are of this form, for k = n − 1.