Neogene activity of the Barrancas Bancas Fault and its relationship with Hydrothermal and volcanic activity

The chronology and nature of the Neogene-Cuaternary deformation in the Central Volcanic Zone (CVZ) in the north of Chile is partially unclear. Some authors have identified compression in isolated areas of the western slopes of the Altiplano-Puna Plateau between the 23,5 and 25ºS, which deformed Miocene and Pliocene deposits (e.g. Gonzalez et al., 2009). In this context, Barrancas Blancas fault, located in the western limit of the Western Cordillera, outcrops in a scarp oriented NS and represents a record of the tectonic activity during the Miocene (Gardeweg et al., 1993). This fault affects to Pampa de Mulas gravels (23,6±1,6 Ma) and Rio Frio Ignimbrites (17,3± 1,7 Ma), and is covered by Miocene-to-Holocene alluvial deposits. In the eastern side of Punta Negra Salar was emplaced the Monognetic Punta Negra volcano, located over the Barrancas Blanca-Fault scarp (10±0,8 Ma) and immediately to the south of Punta Negra volcano, travertine deposits are present in the footwall of Barrancas Blancas fault (10-2 Ma; Quade et al., 2017). This work presents the preliminary results from geomorphologic and stratigraphic data, and structural analysis from Barrancas Blancas fault, and the sediment wedge related with the fault scarpament. These results were combined with geochronological data from magmatic and hydrothermal related rocks/minerals, with the objetive to rebuild the activity of Barrancas Blancas fault and its relation with the magmatic activity during Miocene-Pliocene. Our results show that Barrancas Blancas fault has reverse displacement during Lower Miocene, which caused folding of the Rio Frio ignimbrite and Pampa de Mulas Formation. This period has a maximum age of 11,7 Ma and can be related to the local uplift of the Altiplano-Puna plateau. Using a cinematic analysis, we have identified a period with transtensional activity for Barrancas Blancas fault, which had been coeval with magmatic/hydrothermal activity, the last represented by monogenetic (Punta Negra volcano, ca. 10 Ma) and geothermal activity. The hydrothermal activity in the Barrancas Blancas fault would have lasted until to ca. 2 Ma, coeval with the depositation of alluvial fans related with the scarp backward movement. Our hypothesis suggests that transtensional activity of the Barrancas Blancas fault is related with the uplift and local collapse of the Altiplano

Monte Carlo study of detection systems of explosives and illicit substances using a D-D neutron generator

Prompt gamma neutron activation analysis (PGNAA) using a Deuterium-Deuterium (D-D) neutron generator, is one of the most promising method to detect explosives and illicit substances. Using Monte Carlo methods with MCNP6 code, a model of a DD Generator (DD-110 Adelphi Technology [1]) has been built with one or two NaI(Tl) detectors of 1.5" x 1" size in order to determine an optimal configuration. Several calculations have been performed to analyse the detection power for samples of different explosives: RDX, Ammonium Nitrate, land mines, military and homemade explosives, have been selected. Different models have been made varying moderator and shielding thicknesses (polyethylene and lead) and we conclude that the configuration with 10 cm thickness of polyethylene, is the best configuration to obtain a neutron thermal flux appropriate for detection of these simulated samples of explosive

Analysis of Stationary- and Synchronous-Reference Frames for Three-Phase Three-Wire Grid-Connected Converter AC Current Regulators

The current state of the art shows that unbalance and distortion on the voltage waveforms at the terminals of a grid-connected inverter disturb its output currents. This paper compares AC linear current regulators for three-phase three-wire voltage source converters with three different reference frames, namely: (1) natural (abc), (2) orthogonal stationary (αβ), and (3) orthogonal synchronous (dq). The quantitative comparison analysis is based on mathematical models of grid disturbances using the impedance-based analysis, the computational effort assessment, as well as the steady-state and transient performance evaluation based on experimental results. The control scheme devised in the dq-frame has the highest computational effort and inferior performance under negative-sequence voltage disturbances, whereas it shows superior performance under positive-sequence voltages among the reference frames evaluated. In contrast, the stationary natural frame abc has the lowest computational effort due to its straightforward implementation, with similar results in terms of steady-state and transient behavior. The αβ-frame is an intermediate solution in terms of computational cost.This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed

Quantifying Metal Contamination and Potential Uptake by Phragmites australis Adans. (Poaceae) Along a Subtropical River System

Metal pollution is pervasive across terrestrial and aquatic ecosystems owing to anthropogenic activities. Sediments can accrue high concentrations of metals and act as secondary sources, and thus may be valuable indicators of metal contamination across spatiotemporal scales. In aquatic systems, the extent of metal pollution may be further mediated by transference among sediments and living organisms, with plant metal contaminants potentially predictive of underlying sediment concentrations. The present study thus quantifies the extent of metal pollutants (Na, K, Ca, Mg, Cu, Zn, Mn, B, Fe) across multiple study sites and seasons (cool-dry, hot-wet, hot-dry) in a subtropical river system. Furthermore, uptake by a key macrophyte species, Phragmites australis, was examined and correlated with sediment pollution levels among different plant parts. Overall, sediment pollution load indices differed seasonally, being significantly highest during the cool-dry season irrespective of sampling location, suggesting that periods with reduced water flows can exacerbate metal pollution levels in riverine sediments. Also, metal concentrations were highest in upstream wetland sites, indicating a capacity for metal sink effects in these areas. Overall, macrophytes contained high concentrations of select metals, however composition and concentrations differed across plant parts, with roots containing particularly high concentrations of Fe and B. Correlations between sediment and macrophyte concentrations were mostly non-significant, whilst stem Mn and Fe concentrations correlated significantly negatively and positively to sediment concentrations, respectively. The present study identifies key spatiotemporal differences in multiple metal contaminants in an understudied subtropical aquatic system that align with hydrological regime differences. Whilst macrophytes were not found to be major accumulators, or predictors, of metal contaminants in this study, they may collectively play a central role in concentration regulation in aquatic systems

Analysis of the nutritional and productive behaviour of dairy cows under three rotation bands of pastures, Pichincha, Ecuador

This research was carried out on Pennisetum clandestinum-based pastures to identify the effect of three (3) types of stocking methods with similar forage allowance (8.2 kg of dry matter for 100 kg of live weight) but differing by the occupation times of the rotations (3 h, 24 h, and continuous) on the behaviour and the production of dairy cows. The experimental scheme consisted in three herds of four Holstein Friesian cows grazing three paddocks, one per rotationtype, for one week and replicated three times in a cross-over design. Pasture height and biomass were measured before and after each grazing week and on a daily basis, two cows per herd were monitored during daytime with activity sensors and their milk production was recorded. The main results showed that in all treatments the cows reduced the height of the sward by 40% on average. The cows in the continuous treatment spent more time in meals and tended to have higher average speed during the day than in the 3-h rotation ascribed to a higher exploration of the whole gradable area every day in the continuous treatment and to more time idling animals in the 3-h treatment in anticipation of the opening of new areas to graze over the course of day. Despite those difference in activity, milk production did not differ neither in quantity with an average of 12.4 0.14 kg per day, nor in quality (i.e., fat, protein, non-fatty solids, total solids). We conclude that under our grazing conditions with an intermediate forage allowance and low producing cows, applying a labour intensive stocking method requiring to open new areas every 3 hours does not lead to a significant production increase

State business: gender, sex and marriage in Tajikistan

This article examines the relation of the state to masculinity and sexuality by way of an exploration of the sexual problems of a young man and his wife in Tajikistan at the end of the Soviet era. It suggests that the regime’s inattention to this kind of issue was bound up with the importance to the state of projecting appropriate versions of masculinity. It further posits the idea that the continued refusal of the independent Tajik state to offer appropriate treatments for sexual dysfunction is consistent with the image of modernity President Rahmon wishes to present to the world. The article shows that as masculinity discursively occupies the superior gender position, with men expected to dominate, the state is itself impotent to respond when they are, in fact, unable to do so in sexual practice. However, the myth of male dominance persists to the point that it may prevent women from seeing beyond their subordination and finding mutually beneficial solutions in their familial and sexual relationships

Attitudes toward westbound refugees in the East German press

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67107/2/10.1177_002200277001400303.pd