[1] We investigate the spatial relationship between selfpotential (SP), soil CO 2 flux, and temperature and the mechanisms that produce SP anomalies on the flanks of Masaya volcano, Nicaragua. We measured SP, soil CO 2 fluxes (<1 to 5.0 Â 10 4 g m À2 d À1 ), and temperatures (26 to 80°C) within an area surrounding a normal fault, adjacent to Comalito cinder cone (2002 -2003). These variables are well spatially correlated. Wavelengths of SP anomalies are 100 m, and high horizontal SP gradients flank the region of elevated flux and temperature. Carbon isotopic compositions of soil CO 2 (d 13 C = À3.3 to À1.1%) indicate a deep gas origin. Given the presence of a deep water table (100 to 150 m), high gas flow rates, and subsurface temperatures above liquid boiling points, we suggest that rapid fluid disruption is primarily responsible for positive SP anomalies here. Concurrent measurement of SP, soil CO 2 flux, and temperature may be a useful tool to monitor intrusive activity.

An efficient and effective inversion and uncertainty quantification approach is proposed for estimating eruption parameters given a data set collected from a tephra deposit. The approach is model independent and here is applied using Tephra2, a code that simulates advective and dispersive tephra transport and deposition. The Levenburg‐Marquardt algorithm is combined with formal Tikhonov and subspace regularization to invert eruption parameters; a linear equation for conditional uncertainty propagation is used to estimate posterior parameter uncertainty. Both the inversion and uncertainty analysis support simultaneous analysis of the full eruption and wind field parameterization. The combined inversion/uncertainty quantification approach is applied to the 1992 eruption of Cerro Negro and the 2011 Kirishima‐Shinmoedake eruption. While eruption mass uncertainty is reduced by inversion against tephra isomass data, considerable uncertainty remains for many eruption and wind field parameters, such as plume height. Supplementing the inversion data set with tephra granulometry data is shown to further reduce the uncertainty of most eruption and wind field parameters. The eruption mass of the 2011 Kirishima‐Shinmoedake eruption is 0.82 × 1010 kg to 2.6 × 1010 kg, with 95% confidence; total eruption mass for the 1992 Cerro Negro eruption is 4.2 × 1010 kg to 7.3 × 1010 kg, with 95% confidence. These results indicate that eruption classification and characterization of eruption parameters can be significantly improved through this uncertainty quantification approach.

. Can. J. Chem. 62, 981 (1984).Sulfur-33 chemical shifts have been measured for a number of simple compounds, e.g. SF6, HFSO,, XzSOz, SOz, CI2SO, CH3SH, H2S, and OCS, which have not been previously reported. Our results indicate that the range of "S chemical shifts is approximately 1000 ppm, slightly less than that observed for 170 and approximately one half the range reported for 77Se. Using the "S nuclear spin-rotation constant of OCS measured by molecular-beam electric resonance and Flygare's procedure, an absolute "S shielding constant of 843 t 12 ppm is calculated for OCS, permitting an approximate absolute shielding scale to be proposed for this nucleus. On a mesure les deplacements chimiques du soufre-33 d'un certain nombrc de composCs simples (comme le SF,, le HFS03, le XZS02, le SOZ, le CIzSO, le CH3SH. le HZS et le OCS) qui n'avaient pas tti CtudiCs antkrieurement. Nos rksultats indiquent que les diplacements chirniques du "S s'etalent sur environ 1000 ppm; cette valeur n'cst que ICgkrement infkrieure aux valeurs observees pour le 170 et n'est approximativement que la moitie de la valeur rapportie pour le 7 7~e .En utilisant la constante de rotation de spin nuclkaire du 33S du OCS niesurCe par resonance electrique de faisceau mol6culaire ct par la mCthode de Flygare, on peut calculer que la constante de blindage du "S du OCS est &gale 843 t 12 ppm; ceci permet de proposer une Cchelle absolue et approximative du blindage provoque par ce noyau.[Traduit par le journal]

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An advanced design system has been developed for combustor flow analysis. The system is based on the finite-volume methodology and is of second-order numerical accuracy. Use of co-located grids and Cartesian velocities offers significant advantages over previous staggered-grids, covariant-velocities based schemes. The physicochemical effects are simulated by the standard k-ε model for turbulence, the eddy-breakup model with a two-step general hydrocarbon chemistry for combustion, and a stochastic Lagrangian transport and evaporation model for spray. The developed design system has been applied to analyze a production gas turbine combustor configuration and several design changes. The calculated exit-plane temperature profiles compare well against full-scale rig data. The trends of the exit temperature profiles, showing the effect of design changes to the geometry and flow-splits of various combustor features, are well predicted. The study demonstrates the developed design system to be a robust and viable tool for analyzing and guiding combustor design.