1,205 research outputs found

    RECUPERACIÓN DE PERCLORETILENO EN INDUCALSA

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    A recovery system for perchlorine ethylene from hazardous liquid waste (Ministry Agreement 026 MAE) which stems from shoe making polyurethane sole washing has been designed (Brito H. / Rodríguez B., 2014). Such waste is directly disposed into the environment, causing losses in flora and fauna (GUARIN, O. / RUEDA, G. / PEREZ, H. 2010). Besides contributing with environmental liabilities, the recovered perchlorine ethylene complies the requirements of the DIRSA safety card, because of what it is reutilized in the manufacture process, which contributes to the decrease of production costs and the conservation of the ecosystem. This hazardous waste should be delivered to an environmental manager before paying for its transportation and final disposal (90 USD per kg of waste). For this reason, INDUCALSA along with ESPOCH researchers carried out a scaling of the recovery system by working with 20 samples of perchlorine ethylene – silicone during a lapse of four weeks. An initial characterization was followed by in – lab recovery to measure the variables (temperature, time, input and output flow) with whom the process was scaled for 45,73 Kg/h of waste. The pH, density, viscosity and IR spectrum of the obtained product were analyzed. They showed the purity of the solvent (Disolventes Reunidas, S.A., 2003), which is acceptable because of its high economic value in the market as well as the contribution to the change of the productive matrix in Ecuador (SENPLADES, 2012)

    Non-random distribution of biocrust in a natural arid environment in the northern mexican plateau

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    Abstract. Biocrust, as photosynthetic organisms, has been considered to show an inversely proportional relationship with vascular plant cover. However, some studies report association and facilitation relationships between them. This research explores whether i) biocrust is associated with shrub species, ii) biocrust cover is higher in undershrub microenvironments than in open areas between plants and, iii) soil moisture and solar radiation affect biocrust distribution. Biocrust cover was analyzed by morphotype in microenvironments under the canopy of two dominant shrub species (Larrea tridentata and Parthenium incanum) and in open areas. Soil moisture and solar radiation were recorded at each microenvironment. Thirty-three interception lines (975 points) were used to analyze the association between vascular plants and biocrust and 20 sampling plots to estimate morphotype cover. Results reveal a positive association between biocrust and plant species compared to open areas. Lichens and cyanobacteria showed a higher cover under L. tridentata than under P. incanum and in open areas, suggesting a species-specific facilitative association with L. tridentata, maybe due to a higher soil water content in this microenvironment. Mosses had lower cover in the open area where the highest solar radiation was recorded. Lichens and cyanobacteria distribution appeared to be related to soil moisture. Keywords: creosote bush, cyanobacteria, lichens, mosses, northeastern Mexic

    Valoración de la motivación sobre el colpbol de los alumnos de educación física de primaria en función del tamaño del balón.

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    El nivel motivacional del alumnado en la etapa de Educación Primaria resulta relevante en el proceso de aprendizaje. En este estudio se ha analizado el nivel motivacional del estudiantado al practicar colpbol según el tamaño del móvil (tamaño oficial vs balón de menor tamaño), analizando diferencias en función de la edad y el género. En el estudio participaron 76 alumnos (40 varones y 36 mujeres) entre los 9 y 14 años (M edad= 10’89; DT= ±1,12). Los resultados del estudio señalan que la motivación del alumnado aumentó al utilizar un móvil federado y disminuyó al usar un balón menor. Esta motivación también mostró diferencias en función del género y la edad, porque los varones y los discentes con menor edad mostraron mayor motivación que las mujeres y los estudiantes mayores. Por lo tanto se concluye que el uso de móviles de mayor tamaño motiva más al alumnado y lo que favorece la significatividad del proceso de aprendizaje. The motivational level of students in the Primary Education stage is relevant in the learning process. In this study we analysed the motivational level of students when playing colpball according to the size of the mobile (official size vs. smaller size ball), analysing differences according to age and gender. The study involved 76 students (40 boys and 36 girls) between 9 and 14 years of age (M age= 10.89; SD= ±1.12). The results of the study show that the motivation of the pupils increased when using a federated mobile phone and decreased when using a smaller ball. This motivation also showed differences according to gender and age, because males and younger students showed higher motivation than females and older students. Therefore, it is concluded that the use of larger mobiles motivates students more, which favours the meaningfulness of the learning process

    Mañana today: a long view of economic value creation in Latin America

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    This commentary concerns the significant opportunities which the global economy’s current nearshoring trend offers the Latin American and Caribbean (LAC) region owing to a US–China decoupling. Yet the region, generally, is woefully unprepared. The state of the LAC will make or break the peoples’ attempts to exploit the new potential to better themselves. Yet the short-termist myopia and public policy neglect of politicians is the greatest obstacle to the kind of development the region needs the most: high-quality FDI enabling educated innovators to push LAC up the rank of global value chains; or else it will be trapped in middle income, at best

    The Palomar Testbed Interferometer Calibrator Catalog

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    The Palomar Testbed Interferometer (PTI) archive of observations between 1998 and 2005 is examined for objects appropriate for calibration of optical long-baseline interferometer observations - stars that are predictably point-like and single. Approximately 1,400 nights of data on 1,800 objects were examined for this investigation. We compare those observations to an intensively studied object that is a suitable calibrator, HD217014, and statistically compare each candidate calibrator to that object by computing both a Mahalanobis distance and a Principal Component Analysis. Our hypothesis is that the frequency distribution of visibility data associated with calibrator stars differs from non-calibrator stars such as binary stars. Spectroscopic binaries resolved by PTI, objects known to be unsuitable for calibrator use, are similarly tested to establish detection limits of this approach. From this investigation, we find more than 350 observed stars suitable for use as calibrators (with an additional 140\approx 140 being rejected), corresponding to 95\gtrsim 95% sky coverage for PTI. This approach is noteworthy in that it rigorously establishes calibration sources through a traceable, empirical methodology, leveraging the predictions of spectral energy distribution modeling but also verifying it with the rich body of PTI's on-sky observations.Comment: 100 pages, 7 figures, 7 tables; to appear in the May 2008ApJS, v176n

    Coastal risk mitigation by green infrastructure in Latin America

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    This paper aims to highlight the prevailing experiences of Latin America and to clarify what ‘green infrastructure’ entails in addition to describing seven case studies from a range of coastal ecosystems (wetlands, coastal dunes, beaches and coral reefs) at scales varying from local to regional. The case studies are categorised according to their degree of naturalness (nature-based, engineered ecosystems, soft engineering, ecologically enhanced hard infrastructure and de-engineering). Generally, the implementation of green infrastructure projects aims to increase resilience, enhance the provision of ecosystem services, recover biodiversity, reduce the negative effects of hard infrastructure and implement corrective measures. The greatest benefits of these projects relate to the creation of multi-functional spaces, which often combine the above advantages with improved opportunities for recreation and/or economic activities. It is hoped that this paper will disseminate the experience in green infrastructure among academics and practitioners and stimulate wider adoption of green infrastructure projects and good practices

    CONOCIMIENTOS QUE TIENEN LOS ALUMNOS DE ENFERMERÍA DE LA HIPERTENSIÓN ARTERIAL.

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    Introduction: Knowledge about hypertension among nurses is a subject of great concern due to their important role in prevention, health education, control and follow-up of hypertensive patients. As hypertension is a prevalent health condition in western societies, the goal of this work is to assess the level of knowledge about high blood pressure in a sample of nursing students, as future professionals of this discipline. The results will help us to improve their formation and their lifestyle habits. Methods: Descriptive study. Variables were analysed using Chi-square tests, complemented with residual analysis.Los conocimientos que sobre la hipertensión arterial pueden tener las enfermeras en el desarrollo de su actividad profesional tienen una gran importancia, dada su responsabilidad en este campo, tanto en la prevención de los factores de riesgo, realizando educación sanitaria, como en el control de la presión arterial y en los cuidados, cuando se producen complicaciones. En este trabajo pretendemos profundizar en los conocimientos de los alumnos de enfermería, como futuros profesionales, en un tema tan frecuente en las sociedades desarrolladas como es la hipertensión arterial, para así poder mejorar su formación y sus hábitos de vida no siempre saludables. El objetivo de este trabajo es profundizar en los conocimientos que sobre la hipertensión arterial tienen los alumnos de la Escuela de Enfermería de la Universidad de Murcia. Material y método: se realizó un estudio descriptivo de las variables y los análisis estadísticos correspondientes de X2 de Pearson, complementado con un análisis de residuos

    The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

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    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.Comment: 15 pages, 4 figures, version to be published in PR

    VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

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    VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro
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