Diseño y fabricación de un prototipo de máquina de rotomoldeo para ensayos de procesabilidad de materiales termoplásticos

[ES] El objetivo de este proyecto es realizar el trabajo fin de grado para terminar mis estudios, se parte de la idea de realizar un prototipo de lo que sería un horno para realizar pequeñas piezas de plástico o ensayos de materiales. El proceso de diseño de un proyecto mecánico trae una serie de fases para poder llevarlo adelante, y creo que puedo aportar mi experiencia en Rotomoldeo por ese motivo se tiene la ilusión de realizar este proyecto, el planteamiento inicial del proyecto consta de la búsqueda de información, creatividad y alternativas de diseño teniendo que modificar piezas después de diseñar para adaptarlas a la funcionalidad que deseamos. Un proceso de síntesis y análisis, diseño del prototipo y una optimización de la misma para ello se analizarán varios factores para una posible mejora de diseño de piezas. Interesa que el proyecto sea también intuitivo y fácil de usar, ya que, aunque va dirigido para realizar pequeñas pruebas o ensayos en la universidad, también se realiza de una manera sencilla aprovechando unas piezas de un prototipo que nunca se había puesto en marcha, como la base, el motor y el control de temperatura, estas piezas nos servirán para realizar nuestro proyecto a un menor coste de piezas y nos supondrá un gran reto. También nos supondrá tener más trabajo para realizar las medidas el diseño de piezas adaptadas al prototipo. Se trata de diseñar con solidworks 2017 y Ansys18 para fabricar las piezas necesarias, con sus estudios de cálculos de elementos finitos (FEA) correspondientes para poner en funcionamiento este horno. También se aportan cálculos realizados en Wolfram Mathematica 10.3 y KiSSsoft para cálculo de rodamientos. Para el desarrollo de este horno se parte de una base de acero rectangular lo suficientemente resistente para soportar el peso y el calor del horno. La idea es realizar un horno con una resistencia obtenida que podamos cambiar fácilmente el molde, que sólo se pueda fabricar una pieza debido al tamaño reducido del horno y se pueda realizar ensayos de varios materiales como policloruro de vinilo (PVC) o polietileno. Se realizan varios ensayos con distintas temperaturas. El desmoldeo y enfriamiento se realizan rápido no hace falta desconectar resistencia bajo la extracción del molde se puede realizar enfriamiento rápido bajo el agua o a temperatura ambiente, dejando dar vueltas un tiempo determinado. Se ha buscado piezas, rodamientos de bajo coste para optimizar costes de la fabricación de nuestro horno también se ha tenido en cuenta que debe cumplir una calidad y unos mínimos establecidos por ello se realizará de una manera sencilla y segura.Capelo Tomás, JJ. (2017). Diseño y fabricación de un prototipo de máquina de rotomoldeo para ensayos de procesabilidad de materiales termoplásticos. http://hdl.handle.net/10251/98908TFG

The coastal marine mollusks from northern Macanao Peninsula, Margarita Island, Venezuela

En este estudio se analiza la composición y distribución de los moluscos marinos litorales del norte de la península de Macanao, Isla de Margarita, recolectados entre febrero y mayo de 2007 en trece localidades. Las colectas se hicieron manualmente y con equipo ligero de submarinismo. Se estudiaron 2270 ejemplares, distribuidos en 68 familias, 106 géneros y 152 especies, representantes de las clases Bivalvia Linnaeus, 1758, Gastropoda Cuvier, 1797 y Polyplacophora Gray, 1821. Los gasterópodos fueron la clase dominante con 89 especies, siendo las especies con mayor distribución Lottia antillarum (Sowerby, 1831) y Purpura patula (Linnaeus, 1758) con 84,6%. En bivalvos (55) las especies con mayor distribución fueron Isognomom bicolor (C.B. Adams, 1845) con una presencia de 76,9% y Arca zebra (Swainson, 1833) con 69,2%; y en los polyplacophoros Chiton marmoratus Gmelin, 1791 y Chiton tuberculatus Linné, 1758 con 69,2% y Acanthopleura granulata (Gmelin, 1791) con 53,8%. Los valores más altos de diversidad, equidad y riqueza se obtuvieron en la localidad VII de El Faro de Punta Tigre II con un H´ de 3,8 bits/ind, J´ 0,80 y una riqueza específica de 83; y los más bajos en la localidad VIII de La Auyama con un H´ de 2,17 bits/ind J` 0,95 y 10 especies. De los gasterópodos, 40,4% fueron carnívoros y el resto 59,6% herbívoros. En la clase Bivalvia, 49 especies (89,7%) fueron filtradores suspensívoros y solo 6 (11,3%) colectores de materia orgánica depositada. En general esta elevada riqueza es producto de la heterogeneidad de ambientes y sustratos, la elevada productividad de sus aguas y el bajo grado de intervención antrópica en la mayoría de sus localidades.The composition and distribution of littoral marine molluscs from northern Macanao Peninsula, Margarita’s Island are studied. The samples were collected in thirteen sites between February and May 2007. The captures were performed manually and with the aid of snorkeling. Overall, 2270 individuals were studied. They were distributed among 68 families, 106 genera and 152 species, belonging to Bivalvia Linnaeus, 1758, Gastropoda Cuvier, 1797 and Polyplacophora Gray, 1821 classes. The Gastropods were the dominant class with 89 species, being Lottia antillarum (Sowerby,1931) and Purpura patula (Linnaeus,1758 ) the two species with greater distribution, present in 84.6% of the samples. Among the 55 bivalve species identified the ones with higher distribution were Isognomom bicolor (C.B. Adams, 1845) present in 76.9% and Arca zebra in 69.2% of the samples. For the Polyplacophora, Chiton marmoratus Gmelin, 1791 and C. Tuberculatus Linne, 1758 were present in 69.2% of the samples and Acanthopleura granulata (Gmelin, 1791) in 53.8%. The highest value in diversity, evenness and richness were obtained at the locality VII of El Faro de Punta Tigre II with (H`) 3.80 bits/ind, (J`) 0.80 and specific richness of 83. The lowest values were found at the locality VIII of La Auyama with (H`) 2.2 bits/ind (J`) 0, 95 and 10 species. Among the gastropods, 40.4% were carnivores and the rest (59.6%) were herbivores. In the class Bivalvia, 49 species (89.7%) were suspension feeders and only 6 (11.3%) were surface deposit feeders. All the species of Polyplacophora were herbivores. In general, this high specific richness is the result of the heterogeneity of environments and substrates, the richness of macroalgae, the high productivity of the waters and the low degree of anthropic intervention in most of the sites.Fil: Capelo, Juan Carlos. Fundación La Salle de Ciencias Naturales; VenezuelaFil: Rada, Martin. Universidad de Oriente; VenezuelaFil: Sole, Maria. Fundación La Salle de Ciencias Naturales; VenezuelaFil: Buitrago, Joaquin. Fundación La Salle de Ciencias Naturales; VenezuelaFil: Grune Loffler, Sylvia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Narvaez, Jose. Fundación La Salle de Ciencias Naturales; Venezuel

Sprint performance and mechanical outputs computed with an iPhone app: Comparison with existing reference methods

The purpose of this study was to assess validity and reliability of sprint performance outcomes measured with an iPhone application (named: MySprint) and existing field methods (i.e. timing photocells and radar gun). To do this, 12 highly trained male sprinters performed 6 maximal 40-m sprints during a single session which were simultaneously timed using 7 pairs of timing photocells, a radar gun and a newly developed iPhone app based on high-speed video recording. Several split times as well as mechanical outputs computed from the model proposed by Samozino et al. [(2015). A simple method for measuring power, force, velocity properties, and mechanical effectiveness in sprint running. Scandinavian Journal of Medicine & Science in Sports. https://doi.org/10.1111/sms.12490] were then measured by each system, and values were compared for validity and reliability purposes. First, there was an almost perfect correlation between the values of time for each split of the 40-m sprint measured with MySprint and the timing photocells (r = 0.989–0.999, standard error of estimate = 0.007–0.015 s, intraclass correlation coefficient (ICC) = 1.0). Second, almost perfect associations were observed for the maximal theoretical horizontal force (F0), the maximal theoretical velocity (V0), the maximal power (Pmax) and the mechanical effectiveness (DRF – decrease in the ratio of force over acceleration) measured with the app and the radar gun (r = 0.974–0.999, ICC = 0.987–1.00). Finally, when analysing the performance outputs of the six different sprints of each athlete, almost identical levels of reliability were observed as revealed by the coefficient of variation (MySprint: CV = 0.027–0.14%; reference systems: CV = 0.028–0.11%). Results on the present study showed that sprint performance can be evaluated in a valid and reliable way using a novel iPhone app.Actividad Física y Deport

Estudio de factibilidad para la creación de una empresa distribuidora de productos de consumo masivo en la ciudad de Otavalo, provincia de Imbabura

Realizar un diagnóstico situacional para la creación de una empresa distribuidora de productos de consumo masivo en la ciudad de Otavalo, con la finalidad de establecer los aliados, oponentes, oportunidades y riesgos de la inversión.El presente estudio de factibilidad tiene como objetivo principal la creación de una empresa de servicios y comercialización de productos de consumo masivo en la ciudad de Otavalo, Provincia de Imbabura, mismo que ha sido realizado de acuerdo a las necesidades requeridas por los microempresarios de las comunidades. Para ello se realizó objetivos a través de un diagnóstico situacional de las comunidades donde se realizará el estudio, que como resultado brinda la viabilidad del proyecto. A continuación se realizó el marco teórico mismo que servirá como la base y sustento de la investigación para todo el proyecto a realizarse. En el estudio de mercado se valida información una vez realizada las encuestas a todos los microempresarios en donde se puede deducir cuanta demanda y oferta existe dentro de las comunidades de la ciudad de Otavalo, y que al final ha brindado un resultado positivo indicando datos favorables para la continuación del proyecto, además indica la existencia de una demanda insatisfecha en donde se observa un potencial fuerte para la explotación de este nicho de mercado. Luego el estudio técnico en donde se determina el tamaño, ubicación, infraestructura en base a la necesidad del proyecto para las diferentes áreas, así como de sus costos y requerimiento del personal para lo que se estableció las formas de financiación del proyecto. Para luego pasar al estudio financiero en donde se realiza una proyección y análisis, tanto como la rentabilidad que genera el proyecto así como su viabilidad. Además se puede indicar q en el estudio de la estructura administrativa de la empresa se observa su misión, visión, organigrama y cada una de las funciones y descripciones de los cargos establecidos para la empresa. Finalmente se establece los probables impactos que generará la instalación del proyecto

Inserción laboral de los graduados de la carrera de Nutrición y Salud Comunitaria de la Universidad Técnica Del Norte, periodo 2014 - 2018: Labor insertion of the graduates of the Carrera de Nutrición y Salud Comunitaria of the Universidad Técnica del Norte, periodo 2014 - 2018a, 2016

This study responds to the requirements established by the Ley Orgánica de Educación Superior (LOES), the objective was to follow up on the graduates of the Career of Nutrition and Community Health of the UTN, period January 2014 - April 2018. Regarding the methodology, was a descriptive, quantitative-qualitative, cross-sectional study. The population, 460 graduates who, through probabilistic sampling, had a participation of 80 graduates. A face-to-face, electronic or telephone survey was applied. The results indicate that 82% of the graduates belong to the female sex, a mixed race ethnic group with 86%. Regarding job placement, 66% work; As for the time to find the first job, it was less than 6 months with 45%. Regarding satisfaction with the academic training received at the UTN, only 22% reported that it was of little use. On the other hand, thequality of teachers, their theoretical foundation, training in practices, availability of time and methodologies used in learning were classified analogously on a scale of good and very good. Only 3% of the study population is conducting postgraduate studies. In conclusion, 2 out of 3 graduates work in their profession. Most rate the knowledge, skills, and abilities acquired in the undergraduate as good and very good.Este estudio responde a los requisitos establecidos por la Ley Orgánica de Educación Superior, LOES, por lo cual el objetivo  fue realizar el seguimiento a los graduados de la Carrera de Nutrición y Salud Comunitaria de la UTN, periodo enero 2014 - abril 2018. Investigación de tipo descriptiva, cuanti-cualitativa, transversal; población de 460 graduados que mediante muestreo probabilístico se obtuvo una muestra de 80; en los cuales se aplicó una encuesta presencial, electrónica y por teléfono. Los resultados indican que el 82% de los graduados pertenece al sexo femenino, etnia mestiza con el 86%. Respecto a la inserción laboral el 66% trabaja; en cuanto al tiempo para encontrar el primer empleo fue menor a 6 meses con 45%. Respecto a la satisfacción con la formación académica recibida en la UTN sólo el 22% refirió que fue poco útil. Por otra parte, la calidad de docentes, su fundamentación teórica, formación en prácticas, disponibilidad de tiempo y metodologías utilizadas en el aprendizaje fueron catalogadas de manera análoga en forma buena y muy buena. Sin embargo, las tres últimas no superaron el 75% en la escala de buena y muy buena. Sólo el 3% de población de estudio se encuentra realizando estudios de posgrado. En conclusión 2 de cada 3 graduados trabajan en su profesión; califican como bueno y muy bueno a los conocimientos, habilidades y destrezas adquiridas en el pregrado

Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating

[EN] A methodology for dating copper/bronze archaeological objects aged under atmospheric environments using electrochemical impedance spectroscopy (EIS) is described. The method is based on the measurement of resistance associated to the growth of corrosion layers in EIS recorded upon immersion of the pieces in mineral water and applying a bias potential for the reduction of dissolved oxygen. Theoretical expressions for the time variation of such resistance following a potential rate law are presented. Equivalent expressions are derived and applied for estimating the variation of the tenorite/cuprite ratio from their specific voltammetric signals using voltammetry of microparticles data. Calibration curves were constructed from a set of well-documented coins.Financial support from the MEC Projects CTQ2011-28079-CO3-01 and 02 and CTQ2014-53736-C3-2-P which are supported with ERDF funds is gratefully acknowledged.Domenech Carbo, A.; Capelo, S.; Piquero-Cilla, J.; Domenech Carbo, MT.; Barrio, J.; Fuentes, A.; Al Sekhaneh, W. (2016). Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating. Materials and Corrosion. 67(2):120-129. https://doi.org/10.1002/maco.201408048S120129672Friedman, I., & Smith, R. L. (1960). Part I, The Development of the Method. American Antiquity, 25(4), 476-493. doi:10.2307/276634Reich, S., Leitus, G., & Shalev, S. (2003). Measurement of corrosion content of archaeological lead artifacts by their Meissner response in the superconducting state; a new dating method. New Journal of Physics, 5, 99-99. doi:10.1088/1367-2630/5/1/399Scholz, F., Schröder, U., Meyer, S., Brainina, K. Z., Zakhachuk, N. F., Sobolev, N. V., & Kozmenko, O. A. (1995). The electrochemical response of radiation defects of non-conducting materials An electrochemical access to age determinations. Journal of Electroanalytical Chemistry, 385(1), 139-142. doi:10.1016/0022-0728(94)03840-yDoménech-Carbó, A., Labuda, J., & Scholz, F. (2012). Electroanalytical chemistry for the analysis of solids: Characterization and classification (IUPAC Technical Report). Pure and Applied Chemistry, 85(3), 609-631. doi:10.1351/pac-rep-11-11-13Doménech-Carbó, A., Doménech-Carbó, M. T., & Costa, V. (Eds.). (2009). Electrochemical Methods in Archaeometry, Conservation and Restoration. Monographs in Electrochemistry. doi:10.1007/978-3-540-92868-3Doménech-Carbó, A., Doménech-Carbó, M. T., & Peiró-Ronda, M. A. (2011). Dating Archeological Lead Artifacts from Measurement of the Corrosion Content Using the Voltammetry of Microparticles. Analytical Chemistry, 83(14), 5639-5644. doi:10.1021/ac200731qDoménech-Carbó, A., Doménech-Carbó, M. T., Capelo, S., Pasíes, T., & Martínez-Lázaro, I. (2014). Dating Archaeological Copper/Bronze Artifacts by Using the Voltammetry of Microparticles. Angewandte Chemie International Edition, 53(35), 9262-9266. doi:10.1002/anie.201404522Benarie, M., & Lipfert, F. L. (1986). A general corrosion function in terms of atmospheric pollutant concentrations and rain pH. Atmospheric Environment (1967), 20(10), 1947-1958. doi:10.1016/0004-6981(86)90336-7Strandberg, H. (1998). Reactions of copper patina compounds—II. influence of sodium chloride in the presence of some air pollutants. Atmospheric Environment, 32(20), 3521-3526. doi:10.1016/s1352-2310(98)00058-2Cano, E., Lafuente, D., & Bastidas, D. M. (2009). Use of EIS for the evaluation of the protective properties of coatings for metallic cultural heritage: a review. Journal of Solid State Electrochemistry, 14(3), 381-391. doi:10.1007/s10008-009-0902-6Hernandez-Escampa, M., Gonzalez, J., & Uruchurtu-Chavarin, J. (2009). Electrochemical assessment of the restoration and conservation of a heavily corroded archaeological iron artifact. Journal of Applied Electrochemistry, 40(2), 345-356. doi:10.1007/s10800-009-0003-3Angelini, E., Grassini, S., Parvis, M., & Zucchi, F. (2011). An in situ investigation of the corrosion behaviour of a weathering steel work of art. Surface and Interface Analysis, 44(8), 942-946. doi:10.1002/sia.3842Grassini, S., Angelini, E., Parvis, M., Bouchar, M., Dillmann, P., & Neff, D. (2013). An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral. Applied Physics A, 113(4), 971-979. doi:10.1007/s00339-013-7724-1Doménech-Carbó, A., Doménech-Carbó, M. T., Peiró-Ronda, M. A., Martínez-Lázaro, I., & Barrio-Martín, J. (2012). Application of the voltammetry of microparticles for dating archaeological lead using polarization curves and electrochemical impedance spectroscopy. Journal of Solid State Electrochemistry, 16(7), 2349-2356. doi:10.1007/s10008-012-1668-9Degrigny, C., Guibert, G., Ramseyer, S., Rapp, G., & Tarchini, A. (2009). Use of E corr vs time plots for the qualitative analysis of metallic elements from scientific and technical objects: the SPAMT Test Project. Journal of Solid State Electrochemistry, 14(3), 425-435. doi:10.1007/s10008-009-0890-6Souissi, N., Bousselmi, L., Khosrof, S., & Triki, E. (2004). Voltammetric behaviour of an archeaological bronze alloy in aqueous chloride media. Materials and Corrosion, 55(4), 284-292. doi:10.1002/maco.200303719Souissi, N., Triki, E., Bousselmi, L., & Khosrof, S. (2006). Comparaison between archaeological and artificially aged bronze interfaces. Materials and Corrosion, 57(10), 794-799. doi:10.1002/maco.200503974Souissi, N., & Triki, E. (2009). Characterization of ethnographic copper corrosion. Materials and Corrosion, 60(4), 262-268. doi:10.1002/maco.200805068Mata, A. L., Salta, M. M. L., Neto, M. M. M., Mendonça, M. H., & Fonseca, I. T. E. (2010). Characterization of two Roman coins from an archaeological site in Portugal. Materials and Corrosion, 61(3), 205-210. doi:10.1002/maco.200905284Feliu, S., Morcillo, M., & Feliu, S. (1993). The prediction of atmospheric corrosion from meteorological and pollution parameters—II. Long-term forecasts. Corrosion Science, 34(3), 415-422. doi:10.1016/0010-938x(93)90113-uSpence, J. W., Haynie, F. H., Lipfert, F. W., Cramer, S. D., & McDonald, L. G. (1992). Atmospheric Corrosion Model for Galvanized Steel Structures. CORROSION, 48(12), 1009-1019. doi:10.5006/1.3315903Bhattacharjee, S., Roy, N., Dey, A. K., & Banerjee, M. K. (1993). Statistical appraisal of the atmospheric corrosion of mild steel. Corrosion Science, 34(4), 573-581. doi:10.1016/0010-938x(93)90273-jKobus, J. (2000). Long-term atmospheric corrosion monitoring. Materials and Corrosion, 51(2), 104-108. doi:10.1002/(sici)1521-4176(200002)51:23.0.co;2-vBalasubramaniam, R., Laha, T., & Srivastava, A. (2004). Long term corrosion behaviour of copper in soil: A study of archaeological analogues. Materials and Corrosion, 55(3), 194-202. doi:10.1002/maco.200303723Natesan, M., Venkatachari, G., & Palaniswamy, N. (2006). Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India. Corrosion Science, 48(11), 3584-3608. doi:10.1016/j.corsci.2006.02.006Doménech, A., Doménech-Carbó, M. T., Pasies, T., & del Carmen Bouzas, M. (2012). Modeling Corrosion of Archaeological Silver-Copper Coins Using the Voltammetry of Immobilized Particles. Electroanalysis, 24(10), 1945-1955. doi:10.1002/elan.201200252Rosas-Camacho, O., Uquidi-Macdonald, M., & Macdonald, D. D. (2009). Deterministic Modeling of the Corrosion of Low-Carbon Steel by Dissolved Carbon Dioxide and the Effect of Acetic Acid. I-Effect of Carbon Dioxide. doi:10.1149/1.3259806Macdonald, D., & Englehardt, G. (2010). The Point Defect Model for Bi-Layer Passive Films. doi:10.1149/1.3496427Sharifi-Asl, S., Taylor, M. L., Lu, Z., Engelhardt, G. R., Kursten, B., & Macdonald, D. D. (2013). Modeling of the electrochemical impedance spectroscopic behavior of passive iron using a genetic algorithm approach. Electrochimica Acta, 102, 161-173. doi:10.1016/j.electacta.2013.03.143Macdonald, D. D. (2011). The history of the Point Defect Model for the passive state: A brief review of film growth aspects. Electrochimica Acta, 56(4), 1761-1772. doi:10.1016/j.electacta.2010.11.005Doménech-Carbó, A., Lastras, M., Rodríguez, F., Cano, E., Piquero-Cilla, J., & Osete-Cortina, L. (2013). Monitoring stabilizing procedures of archaeological iron using electrochemical impedance spectroscopy. Journal of Solid State Electrochemistry, 18(2), 399-409. doi:10.1007/s10008-013-2232-yBlum, D., Leyffer, W., & Holze, R. (1996). Pencil-Leads as new electrodes for abrasive stripping voltammetry. Electroanalysis, 8(3), 296-297. doi:10.1002/elan.1140080317Doménech-Carbó, A., Doménech-Carbó, M. T., & Peiró-Ronda, Mªa. (2011). ‘One-Touch’ Voltammetry of Microparticles for the Identification of Corrosion Products in Archaeological Lead. Electroanalysis, 23(6), 1391-1400. doi:10.1002/elan.201000739Nair, M. T. ., Guerrero, L., Arenas, O. L., & Nair, P. . (1999). Chemically deposited copper oxide thin films: structural, optical and electrical characteristics. Applied Surface Science, 150(1-4), 143-151. doi:10.1016/s0169-4332(99)00239-1Scott, D. A. (1997). Copper compounds in metals and colorants: oxides and hydroxides. Studies in Conservation, 42(2), 93-100. doi:10.1179/sic.1997.42.2.93Doménech, A., Doménech-Carbó, M. T., & Martínez-Lázaro, I. (2010). Layer-by-layer identification of copper alteration products in metallic works of art using the voltammetry of microparticles. Analytica Chimica Acta, 680(1-2), 1-9. doi:10.1016/j.aca.2010.09.002Doménech, A., Doménech-Carbó, M. T., Pasies, T., & Bouzas, M. C. (2011). Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles. Electroanalysis, 23(12), 2803-2812. doi:10.1002/elan.201100577Li, W. S., Cai, S. Q., & Luo, J. L. (2004). Chronopotentiometric Responses and Capacitance Behaviors of Passive Film Formed on Iron in Borate Buffer Solution. Journal of The Electrochemical Society, 151(4), B220. doi:10.1149/1.1667521Liu, W., Zhang, H., Qu, Z., Zhang, Y., & Li, J. (2009). Corrosion behavior of the steel used as a huge storage tank in seawater. Journal of Solid State Electrochemistry, 14(6), 965-973. doi:10.1007/s10008-009-0886-2Toledo-Matos, L. A., & Pech-Canul, M. A. (2010). Evolution of an iron passive film in a borate buffer solution (pH 8.4). Journal of Solid State Electrochemistry, 15(9), 1927-1934. doi:10.1007/s10008-010-1213-7Park, J.-J., & Pyun, S.-I. (2003). Analysis of impedance spectra of a pitted Inconel alloy 600 electrode in chloride ion-containing thiosulfate solution at temperatures of 298–573 K. Journal of Solid State Electrochemistry, 7(6), 380-388. doi:10.1007/s10008-002-0346-8Ibrahim, M. A., Pongkao, D., & Yoshimura, M. (2001). The electrochemical behavior and characterization of the anodic oxide film formed on titanium in NaOH solutions. Journal of Solid State Electrochemistry, 6(5), 341-350. doi:10.1007/s100080100229Xia, Z., Nanjo, H., Aizawa, T., Kanakubo, M., Fujimura, M., & Onagawa, J. (2007). Growth process of atomically flat anodic films on titanium under potentiostatical electrochemical treatment in H2SO4 solution. Surface Science, 601(22), 5133-5141. doi:10.1016/j.susc.2007.04.211Acevedo-Peña, P., Vázquez, G., Laverde, D., Pedraza-Rosas, J. E., & González, I. (2009). Influence of structural transformations over the electrochemical behavior of Ti anodic films grown in 0.1 M NaOH. Journal of Solid State Electrochemistry, 14(5), 757-767. doi:10.1007/s10008-009-0838-xFabregat-Santiago, F., Bisquert, J., Garcia-Belmonte, G., Boschloo, G., & Hagfeldt, A. (2005). Influence of electrolyte in transport and recombination in dye-sensitized solar cells studied by impedance spectroscopy. Solar Energy Materials and Solar Cells, 87(1-4), 117-131. doi:10.1016/j.solmat.2004.07.017Rubinstein, I. (1987). Electrochemical Impedance Analysis of Polyaniline Films on Electrodes. Journal of The Electrochemical Society, 134(12), 3078. doi:10.1149/1.2100343Lee, S.-J., & Pyun, S.-I. (2006). Assessment of corrosion resistance of surface-coated galvanized steel by analysis of the AC impedance spectra measured on the salt-spray-tested specimen. Journal of Solid State Electrochemistry, 11(6), 829-839. doi:10.1007/s10008-006-0229-5Doménech, A., Doménech-Carbó, M. T., & Edwards, H. G. M. (2008). Quantitation from Tafel Analysis in Solid-State Voltammetry. Application to the Study of Cobalt and Copper Pigments in Severely Damaged Frescoes. Analytical Chemistry, 80(8), 2704-2716. doi:10.1021/ac7024333Mora, N., Cano, E., Polo, J. L., Puente, J. M., & Bastidas, J. M. (2004). Corrosion protection properties of cerium layers formed on tinplate. Corrosion Science, 46(3), 563-578. doi:10.1016/s0010-938x(03)00171-9Bastidas, J. M., Polo, J. L., Cano, E., Torres, C. L., & Mora, N. (2000). Localised corrosion of highly alloyed stainless steels in an ammonium chloride and diethylamine chloride aqueous solution. Materials and Corrosion, 51(10), 712-718. doi:10.1002/1521-4176(200010)51:103.0.co;2-vXu, J., Huang, W., & McCreery, R. L. (1996). Isotope and surface preparation effects on alkaline dioxygen reduction at carbon electrodes. Journal of Electroanalytical Chemistry, 410(2), 235-242. doi:10.1016/0022-0728(96)04545-7Kuang, F., Zhang, D., Li, Y., Wan, Y., & Hou, B. (2008). Electrochemical impedance spectroscopy analysis for oxygen reduction reaction in 3.5% NaCl solution. Journal of Solid State Electrochemistry, 13(3), 385-390. doi:10.1007/s10008-008-0570-yChen, G., Waraksa, C. C., Cho, H., Macdonald, D. D., & Mallouka, T. E. (2003). EIS Studies of Porous Oxygen Electrodes with Discrete Particles. Journal of The Electrochemical Society, 150(9), E423. doi:10.1149/1.159472

Impact of Fish, Mollusk and Seafood Consumption before Sample Donation on Urinary and Toenail Metal Levels in Workers Exposed to Heavy Metals

Introduction: We assessed the impact on metal levels of seafood, mollusk and fish consumption (SMFc) before urine and toenail sample donation among workers exposed to metals. Methods: This is a cross-sectional epidemiological study with 101 workers from the chemical and metal industry and 40 unexposed workers from the services sector. We measured urinary (As, Ba, Be, Cd, Co, Cu, Hg, Li, Mo, Pb, Se, Sr, Tl, V, W and Zn) and toenail (same plus Al, Cr, Fe, Mn, Ni and U) metal levels. Results: Urinary arsenic levels were higher among workers eating seafood or mollusks (102 ppm vs. 55.4 ppm; p = 0.042) or fish (109 ppm vs. 48 ppm; p = 0.007) 8 h before sample donation. Urinary mercury was associated with consumption of blue fish (11.865 ppm) and canned sardines (19.125 ppm) (p = 0.028). With respect to toenails, fish consumption was associated with aluminum (17 ppm vs. 8.6 ppm; p = 0.012) and beryllium (5 ppb vs. 1 ppb; p = 0.017). Arsenic urinary levels were associated with numbers of hours prior to sample collection since latest SMFc (p = 0.001). Conclusion: Among workers exposed to metals, seafood, mollusk and fish consumption is an important determinant of urinary arsenic levels, as sea fish for urinary mercury, but not for other metals.This research received external funding from the Spanish Government (Ministry of Human Health) Fondo de Investigación Sanitaria PI05-2511

Differences between adjusted vs. non- adjusted loads in velocity-based training: consequences for strength training control and programming

Strength and conditioning specialists commonly deal with the quantification and selection the setting of protocols regarding resistance training intensities. Although the one repetition maximum (1RM) method has been widely used to prescribe exercise intensity, the velocity-based training (VBT) method may enable a more optimal tool for better monitoring and planning of resistance training (RT) programs. The aim of this study was to compare the effects of two RT programs only differing in the training load prescription strategy (adjusting or not daily via VBT) with loads from 50 to 80% 1RM on 1RM, countermovement (CMJ) and sprint. Twenty-four male students with previous experience in RT were randomly assigned to two groups: adjusted loads (AL) (nD13) and non-adjusted loads (NAL) (nD11) and carried out an 8-week (16 sessions) RT program. The performance assessment pre- and post-training program included estimated 1RM and full load-velocity profile in the squat exercise; countermovement jump (CMJ); and 20-m sprint (T20). Relative intensity (RI) and mean propulsive velocity attained during each training session (Vsession) was monitored. Subjects in the NAL group trained at a significantly faster Vsession than those in AL (p < 0.001) (0.88 - 0.91 vs. 0.67- 0.68 m/s, with a 15% RM gap between groups for the last sessions), and did not achieve the maximum programmed intensity (80% RM). Significant differences were detected in sessions 3- 4, showing differences between programmed and performed Vsession and lower RI and velocity loss (VL) for the NAL compared to the AL group (p < 0.05). Although both groups improved 1RM, CMJ and T20, NAL experienced greater and significant changes than AL (28.90 vs.12.70%, 16.10 vs. 7.90% and -1.99 vs. - 0.95%, respectively). Load adjustment based on movement velocity is a useful way to control for highly individualised responses to training and improve the implementation of RT programs

Thermal characterization of ethylammonium nitrate

The 20th International Electronic Conference on Synthetic Organic Chemistry session Ionic LiquidsBeyond their traditional usage in fuel cell applications, the category of protic ionic liquids (PILs) has been recently signalled as a potential candidate for battery applications. Despite being the oldest known IL, and of having been extensively characterized in most of its properties, a full thermal and stability analysis of ethylammonium nitrate (EAN) both in its solid and liquid phases is still lacking. In the present work thermal analysis techniques were used to characterize its thermal transitions and thermal stability. A differential scanning calorimeter DSC Q100 TA-Instruments with aluminium pans hermetically sealed was used to determine the different state transitions experienced by the IL during heating and cooling cycles. Results showed that this IL is a very good crystal-former with melting and freezing peaks at 17ºC and -28ºC respectively. Moreover, stability analysis has been performed by means of a thermogravimetric analyser (TGA 7-Perkin Elmer) operating in dynamic and isothermal modes, under nitrogen and dry air atmospheres was used to perform thermal stability analysis. Similar onset temperatures in air and nitrogen of 248±4ºC were obtained. Additionally, activation energy of the degradation process of this IL has been determined using the Arrhenius equationThis work was funded by the Xunta de Galicia (Spain) through grants EM2013/031 and AGRUP2015/11 and by the network REGALIS R2014/015. The financial support of the Spanish Ministry of Economy and Competitiveness through grants MAT2014-57943-C3-1-P, MAT2014-57943-C3-2-P and MAT2014- 57943-C3-3-P is also gratefully acknowledged. Funding from the European Union (COST Action CM 1206) is also acknowledge

Lista de los moluscos (Gastropoda-Bivalvia) dulceacuícolas y estuarinos de la cuenca del Orinoco (Venezuela)

We conducted a literature review and revised museum collections, as well as original datum of the authors, to create a list of the gastropod and bivalve freshwater and estuary mollusk for the venezuelan Orinoco basin. We consolidated a preliminary list of 104 species distributed between the Gastropod (14 families and 58 species) and Bivalve classes (13 families and 45 species). For the gastropods, the Ampullaridae family was the most diverse (22 sp.) and for the bivalves, the Mycetopodidae family (16 sp). In the list, we include the geographic distribution in the Orinoco watershed, as well as information on their local use, their sanitary importance, ecological habitat and the type of substrate associated for each species.Se realizó una revisión bibliográfica y de colecciones en museos, así como de datos originales de los autores, para reconocer las especies dulceacuícolas y estuarinas de moluscos gastrópodos y bivalvos presentes en la cuenca del Orinoco (Venezuela). Se consolida un listado preliminar para la cuenca de 104 especies distribuidas entre la clase Gastropoda (14 familias y 58 especies) y la clase Bivalvia (13 familias y 45 especies). Entre los gastrópodos la familia Ampullaridae fue la más diversa (22 sp.) y entre los bivalvos, Mycetopodidae (16 sp.). Se incluye información sobre la distribución geográfica en las subcuencas de la Orinoquia, además de información de su uso, importancia sanitaria, hábitos ecológicos y tipo de sustrato asociado a las especies.Se realizó una revisión bibliográfica y de colecciones en museos, así como de datos originales de los autores, para reconocer las especies dulceacuícolas y estuarinas de moluscos gastrópodos y bivalvos presentes en la cuenca del Orinoco (Venezuela). Se consolida un listado preliminar para la cuenca de 104 especies distribuidas entre la clase Gastropoda (14 familias y 58 especies) y la clase Bivalvia (13 familias y 45 especies). Entre los gastrópodos la familia Ampullaridae fue la más diversa (22 sp.) y entre los bivalvos, Mycetopodidae (16 sp.). Se incluye información sobre la distribución geográfica en las subcuencas de la Orinoquia, además de información de su uso, importancia sanitaria, hábitos ecológicos y tipo de sustrato asociado a las especies