Search

The rupture of the September 16, 2015, M w 8.3 Illapel earthquake extended over 200 km length along strike, where the southern portion of the rupture area is controlled tectonically by the collision of the Juan Fernandez Ridge at ∼32.5°S. On November 11th, two large aftershocks occurred in less than an hour, at shallow depths and epicenters closely located. Both events occurred beyond, but nearby, the northern limit of the Illapel rupture. We inverted kinematic rupture models by joint inversion of strong-motion and teleseismic body waves datasets. The Akaike's Bayesian Information Criterion (ABIC) was used to estimate the relative weighting between datasets, as well as the weighting of spatial and temporal constraints. The rupture of the first event propagated updip from the hypocenter, and later in a bilateral mode, with large slip to the south. The slip solution yields a total seismic moment of 4.44 × 1019 N m (M w 7.0), and peak-slip of 0.82 m. The epicenter of the second event relocates 15 km southwest with respect to the first one. The rupture of the second event propagated mainly southwards and updip to the trench, re-rupturing an area already broken by the first event. The estimated seismic moment is 3.11 × 1019 N m (M w 6.9), with a maximum slip of 0.59 m. The source durations from their respective moment-rate functions are 35 s, in both models. The spatial slip distribution retrieved for the two events suggests that the upper portion of the megathrust slipped, a region that is usually thought to behave aseismically, controlled by velocity-strengthening friction. We also relocated the earthquake catalog using a double-difference algorithm. The spatial distribution of seismicity shows clusters that are analyzed in different groups, and the most remarkable feature being a strip running parallel - and close by - to the trench region with very low seismicity. The majority of regional moment tensor solutions are thrust faulting mechanisms, and given the centroid depths retrieved, these events are consistent with interplate seismicity. • Source process of two large aftershocks of the 2015 Mw 8.3 Illapel earthquake. • Coseismic ruptures occurred at shallow depth of the megathrust. • A strip running near and parallel to the trench region shows low seismicity. [ABSTRACT FROM AUTHOR]

Background Dalfampridine extended release 10 mg tablets (D-ER) have demonstrated improvement in walking for ambulatory persons with multiple sclerosis (pwMS), termed “responders.” Objective This study examined the extent additional aspects of gait and dexterity change for patients prescribed D-ER. Methods Over 14-weeks, walking endurance, dynamic gait, self-report walking ability andfine and gross dexterity were examined in pwMS prescribed D-ER as a part of routine clinical care. Results The final results (n = 39) validate that a subset of pwMS improve walking speed (Time 25-Foot Walk Test, p < 0.0001). Significant improvements in gait and dexterity were observed even among participants who did not improve walking speed. Improvements were evident in gait and dexterity domains including Six Minute Walk Test, p = 0.007, Six-Spot Step Test, p < 0.0001, Multiple Sclerosis Walking Scale-12, p < 0.0001, Nine Hole Peg Test, p < 0.0001 dominant and non-dominant sides, and Box and Blocks Test, p = 0.005 and 0.002, dominant and non-dominant sides, respectively. Conclusions These findings suggest that D-ER may be a potential treatment for gait impairments, beyond walking speed and dexterity in pwMS. Further investigation regarding D-ER response is warranted. [ABSTRACT FROM AUTHOR]

Abstract: Biomass is so diverse that special care must always be taken in designing plants to handle biomass-based fuels and in the process for its collection, preparation and transportation, because its energy density is such that far greater volumes need to be transported than in the case of fossil fuels. This means higher costs and more associated CO2 emissions. This paper examines the following points concerned with the logistics of biomass: optimum biomass transport distances to plants, transport costs, CO2 emissions relative to CO2 avoided and the surface areas required to grow or collect biomass. Particular emphasis is placed on the logistics of biomass-fired electric power plants rated at 2 MW electrical, a size that enables electric power distribution to be decentralised. The findings reveal that the maximum cost of logistics (not including any collection and preparation stages) is €11.05 per tonne, with emissions amounting to 0.69% of the total CO2 avoided, for the worst-case scenario of distances averaging 100 km around the plant. [Copyright &y& Elsevier]

Abstract: Biomass gasification has yet to consolidate its position compared to other techniques for exploiting biomass energy. Neither the research conducted nor the plants built in recent decades, nor even government support for this technology, have provided a sufficient boost to increase the level of implementation of gasification despite its advantages in aspects such as greater efficiency and the reduction in CO2 emissions, as there are numerous other methods of biomass energy conversion that provide stiff competition. In this paper, gasification techniques have been reviewed in depth and the main factors to be considered in the design of a gasification plant have been outlined. It is observed that there are a great number of factors involved in design and operation of a gasification plant, and many of them are critical. Moreover, having designed a plant according to certain specifications, there is a high probability that these initial conditions can vary, causing a malfunction of the plant. [Copyright &y& Elsevier]

An 18-year time series of monthly NOAA-AVHRR Pathfinder Land burned area was analyzed for the region of tropical Africa, from July 1981 to June 1999. The transition period between NOAA-11 and NOAA-14 platforms from July 1993 to June 1995 was not included due to missing and outlier data. Stability of the time series was addressed for the input variables in the burned area algorithm, reflectance and temperature channels. A Seasonal AutoRegressive Integrated Moving-Average (SARIMA) model was developed for forecasting potential burned area. The SARIMA model identified an autoregressive regular term with 1-month lag and an autoregressive 12-month seasonal term with one season (12 months) component. A cross-correlation between Southern Oscillation Index (SOI) and burned area was statistically significant predictor variable in a time series with 20-month lag. Results show that the SARIMA model with this predictor improved both, fitting and forecasting, residual variance, by 4. 1% and 5. 6%, respectively, thereby, demonstrating potential relationship between SOI and burned area for the study region. Forecasting was estimated by considering only the first 16 years of the monthly burned area in the time series, from July 1981 to June 1997. The prediction for the following 24 months (from July 1997 to June 1999) was within the 95% confidence level indicating that the forecast was a valid characterization of the modeled process. [Copyright &y& Elsevier]

Abstract: The majority concept plays a main role in decision making processes where one of the main problems is to define a decision strategy which takes into account the individual opinions of the decision makers to produce an overall opinion which synthesizes the opinions of the majority of the decision makers. The reduction of the individual values into a representative value of majority is usually performed trough an aggregation process. The most common operator used in these processes is the OWA operator, in which the majority concept can be modelled using fuzzy logic and linguistic quantifiers. In this work the fusion processes and the semantic used for modelling the majority concept in the OWA operators are analyzed and compared in order to present different approach to obtain a feasible majority aggregation value for the decision making problem. [Copyright &y& Elsevier]

The present paper deals with the historical evolution of the northern Bay of Cádiz (SW Spain) between the last eustatic maximum (6.5 ka BP) and the present day, by means of a series of independent proxies. The zone is constituted by the tidal estuary of the Guadalete River, filled with saltmarsh sediments during the late Holocene, due to the sheltering of the zone by a confining outer sandy barrier. The northern border of the Bay records an urban settlement of Phoenician Age (first millennium BC), Doña Blanca. A detailed survey was made in the contact between the Phoenician city and the saltmarshes in order to detect other possible urban structures related to the morphological and sedimentary evolution of this environment during historical times. Two campaigns with GPR Stream-X array were carried out as well as aerial imaging and topographic survey with UAV. In parallel, a total of 8 boreholes were made in different parts of the saltmarshes, including radiocarbon dating of selected samples for estimating sedimentation rates in the saltmarshes. Results obtained by georadar prospection and UAV survey revealed the presence of a second urban settlement on the marginal sedimentary plain, very probably installed upon a sandy fluvial island of the Guadelete River. The urban remains, of Punic Age, are partly covered by clay sediments due to the subsequent evolution of these saltmarshes, where sedimentation rates of up to nearly 2.4 mm/yr have been estimated for environments close to fluvial and/or tidal channels and hence more affected by sediment aggradation during flooding episodes. In recent times, river regulation by dams and the artificial desiccation and cropping of the saltmarshes have interrupted the natural trend of the area towards sedimentary silting up. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermal transmittance of the wall has a linear dependency on clay conductivity. [•] Adding a lightening additive to the clay is the best economical solution. [•] U eq of a wall may be decreased by up to 20%, if we decrease λ clay by up to 50%. [•] An equation has been obtained to estimate the improvement in U eq of a wall. [ABSTRACT FROM AUTHOR]

Abstract: The Mo3Si alloys with different aluminum contents were fabricated by the arc-melting and drop-casting technique, heat treated and then exposed to air at 700, 800, 900 and 1000°C in order to assess their oxidation behavior. Line scan studies led to the assumption that the oxide scale thermally grown at 1000°C was composed of SiO2 which was located closer to the alloy matrix and Al2O3 around the outer surface of the oxidized sample, while the Mo oxide volatilized at this oxidation temperature. The results also showed that the unalloyed sample (Mo3Si) underwent a pest reaction in a short time of exposure, while the sample with 16at.% Al exhibited the best oxidation behavior, which could be attributed to the formation of SiO2 and Al2O3 in the oxide scale. [Copyright &y& Elsevier]

Abstract: The depth of the basement and the structure of shallow sedimentary materials in Mula town (SE Spain) have been estimated applying an association of the spatial autocorrelation (SPAC) method and the horizontal-to-vertical spectral ratio (HVSR) method for ambient noise. Regular pentagonal arrays with radii up to 30m have been employed for velocity computation. A map of predominant periods has also been obtained by applying the HVSR method to a set of 97 ambient noise measurement points of a grid, which covers the terrain equally. This map reveals a general increasing trend in the period values, from the rock outcroppings in the northern part of the town to the central and western zones where the shallow geological materials that cover the basement increase in thickness. S-wave velocity structure derived from ambient noise analysis reflects geological and geotechnical models obtained for sites where both types of raw data were available. [Copyright &y& Elsevier]

Abstract: Several alloys produced by arc cast method were obtained, with Nb additions up to 20at%. The samples were thermo-chemical treated with pulsed plasma nitrided for 24h. A pin-on-disk system was employed to perform wear experiments under non-lubrication condition. After wear analysis, the treated samples in all range of Nb concentrations have shown less mass losses in comparison with samples without surface modification, until the nitrided zone is removed. Surface oxidation studies leaded to the conclusion that the increased wear resistance is due to the higher surface hardness together with the mixture of different Nb, Si and Mo oxides generated during the wear process identified by SEM and chemical analysis. The friction coefficient is of the order of 10−3. The improved specific wear rate is of the order of 10−6 mm3/Nm and shows an increment of 39.9% respect to the samples with 5at% Nb and 10at% Nb, this results clearly show that Nb additions is beneficial for the wear resistance of the alloy. [Copyright &y& Elsevier]