Low-ionization galaxies and evolution in a pilot survey up to z=1

We present galactic spectroscopic data from a pencil beam of 10.75×7.5 centered on the X-ray cluster RXJ0054.0-2823 at z=0.29.We study the spectral evolution of galaxies from z=1 down to the cluster redshift in a magnitude-limited sample at R≤23,for which the statistical properties of the sample are well understood.We divide emission-line galaxies into star-forming galaxies,Low Ionization Nuclear Emission line Regions(LINERs) ,and Seyferts by using emission-line ratios of[OII],Hβ,and[OIII],and derive stella...     

Groundwater recharge assessment in a rural,arid, mid-mountain basin in North-Central Chile

ABSTRACT

A basic component of any hydrogeological study is the magnitude and temporal variation of groundwater recharge. This can be difficult to assess accurately, particularly in arid and semi-arid rainfed mid-mountain zones, as is the situation in the rural, low population density zones of North-Central Chile. In this study, recharge in the Punitaqui Basin, North-Central Chile, was characterized, contrasting the results of two methods: a modified Thornthwaite-Mather (MTM) and discharge recession analysis (DRA). We found a recharge rate of between 1 and 4% of average annual precipitation. Average recharge estimated by the MTM method is consistently higher than that estimated by DRA. Also, DRA tends to smooth the recharge values, resulting in a lower inter-annual variation coefficient. Both methods identified a threshold value of total annual precipitation, above which recharge can be expected to occur, of the order of 180 mm year^?1, consistent with values reported in similar areas.     

A universal kriging approach for spatial functional data

In a wide range of scientific fields the outputs coming from certain measurements often come in form of curves. In this paper we give a solution to the problem of spatial prediction of non-stationary functional data. We propose a new predictor by extending the classical universal kriging predictor for univariate data to the context of functional data. Using an approach similar to that used in univariate geostatistics we obtain a matrix system for estimating the weights of each functional variable on the prediction. The proposed methodology is validated by analyzing a real dataset corresponding to temperature curves obtained in several weather stations of Canada.     

Thermal Drying and Alkaline Treatment of Biosolids: Effects on Nitrogen Mineralization

Biosolids from the Cañeveralejo WWTP were dehydrated by filter press and then applied two processes to reduce pathogens (PRP): thermally dried biosolid (TDB) and alkalinized biosolid (AB). Untreated, dehydrated biosolid (DB) was used as a control. We evaluated the impact of thermal drying and alkaline treatments on nitrogen mineralization in these substrates. Moreover, agronomic rates for biosolid applications to sugarcane were estimated for each of the treatments leading to application rates of 35.8, 36.4, and 54.5 t/ha for DB, TDB, and AB, respectively, to meet the nitrogen requirement (200 kg N/ha) for sugarcane cultivation (Saccharum officinarum). The results showed that the biosolid rates used increased the mineral nitrogen content of soils by an average of 93.8 and 439.8 mg/kg for all biosolids and the PRP (thermal drying and alkaline treatment) in biosolids had significant effects on mineralization rate, showing better results for the TDBs.     

Modelling Microbial Degradation Coupled to Reactive Transport in Groundwater: A Benchmark Analysis

Microbes are ubiquitous in groundwater systems, and they play an important role in the redox state of groundwater and especially on the fate of organic contaminants. In this context, numerical simulations that couple microbial processes to reactive transport models are becoming more popular. In the present work, we revisit the mathematical ground of microbial redox reactions and perform a benchmark analysis of the simulation of aerobic benzene degradation in a shallow and oxidizing aquifer. Numerical results indicate that the two codes tested (one using the finite elements approach and the other using the finite differences approach) lead to very similar results. In addition, the coupling of heterogeneous geochemical reactions to the benchmarked example problem provides a solid basis for the understanding of the redox reactions and the changes on the carbon system triggered by the aerobic degradation of benzene.     

Granite emplacement by crustal boudinage: example of the Calmayo and El Hongo plutons (Córdoba,Argentina)

This study deals with the structure and emplacement of the Calmayo and El Hongo trondhjemite plutons (Famatinian belt of Córdoba, Argentina). It provides structural data from the granites and the country rocks and a study of the magnetic fabric in the plutons. New U/Pb geochronological data yield intrusion ages of 512.1 ± 3.4 Ma and 500.6 ± 4.5 Ma for the Calmayo and El Hongo plutons respectively. The El Hongo massif and the southern part of the Calmayo trondhjemite preserve magmatic structures, whereas the northern domain of Calmayo shows the imprint of solid‐state deformation. The main foliation in the country rocks outlines a boudin‐like pattern at the map scale and the granites are located along boudin necks, suggesting that the emplacement of these trondhjemite plutons was linked to large‐scale boudinage of the country rocks.     

Degassing of Cl, F, Li, and Be during extrusion and crystallization of the rhyolite dome at Volcán Chaitén, Chile during 2008 and 2009

We investigated the distribution of Cl, F, Li, and Be in pumices, obsidians, and crystallized dome rocks at Chaitén volcano in 2008?C2009 in order to explore the behavior of these elements during explosive and effusive volcanic activity. Electron and ion microprobe analyses of matrix and inclusion glasses from pumice, obsidian, and microlite-rich dome rock indicate that Cl and other elements were lost primarily during crystallization of the rhyolitic dome after it had approached the surface. Glass in pumice and microlite-free obsidian has 888?±?121?ppm Cl, whereas residual glass in evolved microlite-rich dome rock generally retains less Cl (as low as <100?ppm). Estimated Cl losses were likely >0.7?Mt Cl, with a potential maximum of 1.8?Mt for the entire 0.8-km³ dome. Elemental variations reflect an integrated bulk distribution ratio for Cl?>?1.7 (1.7 times more Cl was degassed or incorporated into crystals than remained in the melt). Because Cl is lost dominantly as the very last H₂O is degassed, and Cl is minimally (if at all) partitioned into microlites, the integrated vapor/melt distribution ratio for Cl exceeds 200 (200 times more Cl in the evolved vapor than in the melt). Cl is likely lost as HCl, which is readily partitioned into magmatic vapor at low pressure. Cl loss is accelerated by the change in the composition of the residual melt due to microlite growth. Cl loss also may be affected by open-system gas fluxing. Integrated vapor-melt distribution ratios for Li, F, and Be all exceed 1,000. On degassing, an unknown fraction of these volatiles could be immediately dissolved in rainwater.     

Identifying induced variations in the seismic regime by the methods of nonlinear dynamics

The nonlinear analysis of the data on seismicity in the areas where the underground rocks were affected by the injection of fluids, blasting works, and vibrations shows that the technogenous impacts increase the regularity of the seismic regime. The effects of the man-made actions manifest themselves in the formation of stable states characterized by the finite fractal dimension of the attractor and the small dimension of the embedding space. In order to explain the increase in the regularity of the seismic process, we consider the model of motion in the fault zones which is described by the two-parameter friction law. The presence of the stable states paves the way for both forecasting the induced seismic activity and developing the technologies for the controlled forcing of the seismic regime.