9,153 research outputs found
Fabricación de productos de base yeso y sus aplicaciones industriales
En este
trabaj
o se lleva a cabo una revisión de los productos de yeso. Se analizan los métodos de fabricación y las caracterÃsticas técnicas de los productos obtenidos. Asimismo se realiza un estudio de los productos de mayor demanda en el mercado, en base a sus prestaciones técnicasIn this work it is being written a review about gypsum products. It is an analysis about manufacture methods and technical characteristics of the obtain products. So, it is made a study about the products which are the soldest in the market because their technical properties.Peer reviewe
Source energy spectra from demodulation of solar particle data by interplanetary and coronal transport
The data on source energy spectra of solar cosmic rays (SCR), i.e. the data on the spectrum form and on the absolute SCR are of interest for three reasons: (1) the SCR contain the energy comparable to the total energy of electromagnetic flare radiation (less than or equal to 10 to the 32nd power ergs); (2) the source spectrum form indicates a possible acceleration mechanism (or mechanism); and (3) the accelerated particles are efficiently involved in nuclear electromagnetic and plasma processes in the solar atmosphere. Therefore, the data on SCR source spectra are necessary for a theoretical description of the processes mentioned and for the formulation of the consistent flare model. Below it is attempted to sound solar particle sources by means of SCR energy spectrum obtained near the Sun, at the level of the roots of the interplanetary field lines in the upper solar corona. Data from approx. 60 solar proton events (SPE) between 1956-1981. These data were obtained mainly by the interplanetary demodulation of observed fluxes near the Earth. Further, a model of coronal azimuthal transport is used to demodulate those spectra, and to obtain the source energy spectra
Valuation and modeling of EQ-5D-5L health states using a hybrid approach
Background: The EQ-5D instrument is the most widely used preference-based health-related quality of life questionnaire in cost-effectiveness analysis of health care technologies. Recently, a version called EQ-5D-5L with 5 levels on each dimension was developed. This manuscript explores the performance of a hybrid approach for the modeling of EQ-5D-5L valuation data. Methods: Two elicitation techniques, the composite time trade-off, and discrete choice experiments, were applied to a sample of the Spanish population (n=1000) using a computer-based questionnaire. The sampling process consisted of 2 stages: stratified sampling of geographic area, followed by systematic sampling in each area. A hybrid regression model combining composite time trade-off and discrete choice data was used to estimate the potential value sets using main effects as starting point. The comparison between the models was performed using the criteria of logical consistency, goodness of fit, and parsimony. Results: Twenty-seven participants from the 1000 were removed following the exclusion criteria. The best-fitted model included 2 significant interaction terms but resulted in marginal improvements in model fit compared to the main effects model. We therefore selected the model results with main effects as a potential value set for this methodological study, based on the parsimony criteria. The results showed that the main effects hybrid model was consistent, with a range of utility values between 1 and -0.224. Conclusion: This paper shows the feasibility of using a hybrid approach to estimate a value set for EQ-5D-5L valuation data.</p
X Symposium on Probability and Stochastic Processes and the First Joint Meeting France-Mexico of Probability. Proceedings of the symposium and the meeting held in Guanajuato, November 3–7, 2008
Comparative Human and Automatic Evaluation of Glass-Box and Black-Box Approaches to Interactive Translation Prediction
Interactive translation prediction (ITP) is a modality of computer-aided translation that assists professional translators by offering context-based computer-generated continuation suggestions as they type. While most state-of-the-art ITP systems follow a glass-box approach, meaning that they are tightly coupled to an adapted machine translation system, a black-box approach which does not need access to the inner workings of the bilingual resources used to generate the suggestions has been recently proposed in the literature: this new approach allows new sources of bilingual information to be included almost seamlessly. In this paper, we compare for the first time the glass-box and the black-box approaches by means of an automatic evaluation of translation tasks between related languages such as English–Spanish and unrelated ones such as Arabic–English and English–Chinese, showing that, with our setup, 20%–50% of keystrokes could be saved using either method and that the black-box approach outperformed the glass-box one in five out of six scenarios operating under similar conditions. We also performed a preliminary human evaluation of English to Spanish translation for both approaches. On average, the evaluators saved 10% keystrokes and were 4% faster with the black-box approach, and saved 15% keystrokes and were 12% slower with the glass-box one; but they could have saved 51% and 69% keystrokes respectively if they had used all the compatible suggestions. Users felt the suggestions helped them to translate faster and easier. All the tools used to perform the evaluation are available as free/open–source software.Work partially funded by the Generalitat Valenciana through grant ACIF/2014/365, the Spanish government through project EFFORTUNE (TIN2015-69632-R), and by the Government of the Republic of Kazakhstan
Surface properties and fatigue failure analysis of alloy 718 surfaces milled by abrasive and plain waterjet
This work analyzes the surfaces obtained in alloy 718 when they are milled by abrasive waterjet (AWJ) at different conditions, and the effect of main process parameters on the characteristics of these surfaces. This analysis revealed that all surfaces have a homogeneous roughness in the transversal and the longitudinal directions, present embedded abrasive particles and have hardened about 50% with respect to the untreated bulk alloy 718. In addition, plain waterjet (PWJ) technology was used for removing the abrasive particles embedded in surfaces of alloy 718 milled previously by AWJ technology. The effect of this process on the surface characteristics is also analyzed. For all tested conditions, this technology removed all the particles embedded in the surface. In addition, the PWJ technology process in general smoothened the surfaces produced by AWJ milling and it also released near-surface stress. Finally, fatigue tests revealed lower performance of the treated specimens in comparison to untreated specimens, due to crack-like surface irregularities introduced by the treatments.The authors acknowledge the support of the
Ministry of Economy and Competitiveness of the Spanish Government
for support of project EVOCA II (reference DPI2013-45308-P)
An Open-Source Web-Based Tool for Resource-Agnostic Interactive Translation Prediction
We present a web-based open-source tool for interactive translation prediction (ITP) and describe its underlying architecture. ITP systems assist human translators by making context-based computer-generated suggestions as they type. Most of the ITP systems in literature are strongly coupled with a statistical machine translation system that is conveniently adapted to provide the suggestions. Our system, however, follows a resource-agnostic approach and suggestions are obtained from any unmodified black-box bilingual resource. This paper reviews our ITP method and describes the architecture of Forecat, a web tool, partly based on the recent technology of web components, that eases the use of our ITP approach in any web application requiring this kind of translation assistance. We also evaluate the performance of our method when using an unmodified Moses-based statistical machine translation system as the bilingual resource.This work has been partly funded by the Spanish Ministerio de EconomÃa y Competitividad through project TIN2012-32615
Effect of Different Urine Cow Nitrogen Rates and Different Moisture Conditions on Nitrogen Mineralization in an Andisol from Southern Chile
Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be an equivalent to approximately 1000 kg N ha−1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of different wetting and drying conditions mimicking the variation of weather conditions on the nitrification process, from urea to NH4+ and total oxidized nitrogen (TON), throughout time. In addition, the inhibition on nitrification driven by the accumulation of NH3 at high rates of N applied to an Andisol have not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N ha−1 (Low N), 461 kg N ha−1 (Medium N), 921 kg N ha−1 (High N), and de-ionized water as Control. Further, three moisture conditions were imposed: constant moisture (CM), drying-rewetting (DRW) cycles at 7 days interval, and soil drying (SD). Destructive soil cores samples were evaluated for top and bottom halves individually every 7 days over a 36-d period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was var-iable over time. The High N was associated with elevated NH3 concentrations and could explain that total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in the soil under different chemical and physical conditions determines nitrification, thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils
Paleoenvironmental Changes at ODP Site 702 (South Atlantic): Anatomy of the Middle Eocene Climatic Optimum
The Middle Eocene Climatic Optimum (MECO) was an unusual global warming event that interrupted the long-term Eocene cooling trend ca. 40 Ma. Here we present new high-resolution bulk and benthic isotope records from South Atlantic ODP Site 702 to characterize the MECO at a high latitude setting. The MECO event, including early and peak warming as well as recovery to background levels, had an estimated ~300 Kyr duration (~40.51 to ~40.21 Ma). Cross-plots (delta O-18 vs. delta C-13) suggest that the mechanisms driving coupled changes in O and C isotope values across the MECO were weaker or absent before the event. The paleoecological response has been evaluated by quantitative analysis of calcareous nannofossils and benthic foraminifera assemblages. We document a shift in the biogeographical distribution of warm and temperate calcareous nannoplankton taxa, which migrated toward higher latitudes due to increased temperatures during the MECO. Conversely, changes in the organic matter flux to the seafloor appear to have controlled benthic foraminifera dynamics at Site 702. Benthic phytodetritus exploiting taxa increased in abundance coinciding with a positive delta C-13 excursion, ~150 Kyr before the start of the delta O-18 negative excursion that marks the start of MECO warming. Our data suggest that paleoecological disturbance in the deep sea predates MECO delta O-18 excursion and that it was driven by changes in the type and/or amount of organic matter reaching the seafloor rather than by increased temperature
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