19 research outputs found

    IMPACT OF FREIGHT TRANSPORTATION ON CD. JUÁREZ ENVIRONMENT AND REVIEW OF AERODYNAMIC DRAG REDUCTION DEVICES FOR HEAVY TRUCKS

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    Nowadays studying the ways in which greenhouse gas emissions may be reduced from all sectors of human been activities, including the transportation sector, became extremely important. The purpose of this investigation is study environmental impact of freight transportation in cd. Juarez area and review of aerodynamic drag reduction devices for heavy trucks to better understand what technologies or practices can be applied to highway tractor and trailer combinations to reduce aerodynamic drag without negatively affecting the usefulness or profitability of the vehicles.En la actualidad, el estudio de como disminuir las emisiones de gases de efecto invernadero de todos los sectores, incluido el transporte es muy importante. El propósito de este trabajo es estudiar el impacto ambiental del transporte de carga en Cd. Juárez y revisar los dispositivos de reducción de arrastre aerodinámico para camiones pesados para tener un mayor entendimiento de que tecnologías o prácticas pueden ser implementadas en el transporte de carga para reducir el arrastre aerodinámico sin afectar el desempeño de los vehículos

    Experimental Study of the Influence of Stitched Nylon Threads in Glass-Fiber-Reinforced Polymer Two-Dimensional Multilayer Composite on Tensile Strength

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    Stitched filaments are known to modify the mechanical properties of glass-fiber-reinforced polymers 2D (GFRPs 2D), so studying the effect on mechanical properties is underway to determine the critical variables involved. This research focuses on the study of the tensile strength effect of stitched low-density Barkley FBA BGQS15-15 nylon monofilament on biaxial E-Glass Saertex 830 g/m2 (+/−45°) cured with Polyester Sypol Resin 8086 CCP using a vacuum infusion process. Four specimens were made with longitudinal distances between the stitched reinforcements of 0.5, 1.0, 1.5, and 2.0 cm, respectively. Tensile strength tests based on standard ASTM D3039 were performed to study how stitching can affect toughness, Young’s modulus, deformation, ultimate strength, and yield strength. The results indicated that the stitching increases Young’s modulus up to 99.2%, UTS is increased by up to +3.14%, deformation decreases by up to −41.66%, and toughness decreases by up to −36.89%. Although the stitching’s main function is to increase interlaminar resistance, it also induces the formation of stress concentrations by the new threads, and premature failure in the matrix was shown

    Delamination and tensile effect of fine z-binder reinforced on fiberglass/polyester composite for aerospace applications

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    Delamination propagation in laminated composite materials is a common issue that always concerns us when we consider composites for structural purpose. Many possible solutions have been studied; the most famous is the three-dimensional (3D) woven composites materials, which have promising interlaminar fracture resistance but at the cost of increasing density, which for aerospace industry is very important. In this chapter, mode 1 double cantilever beam (DCB) interlaminar fracture toughness tests according to the American Society for Testing and Materials (ASTM) D5528 standard were performed on composite specimens made of E-Glass Saertex 830 g/m2 Biaxial (+/−45°) with Sypol 8086 CCP polyester resin with orthogonal z-axis oriented yarn woven of 0.22 mm diameter nylon monofilament. Four specimens were made with a longitudinal distance between the warp binders of 0.5, 1, 1.5, and 2 cm, respectively. A tensile test according to the ASTM D3039 standard was performed to study how z-binder may affect tensile resistance. The results show a considerable increase in interlaminar fracture toughness, several stress concentrators have been created because of the new yarn and premature failure in the matrix

    Corrosion behavior of aluminum-carbon fiber/epoxy sandwich composite exposed on NaCl solution

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    For years, the aeronautical industry has employed different types of materials to satisfy its high-performance requirements. Fiber-metal laminates are used due to their combination of lighter weight and the high mechanical properties of reinforced metal and carbon. We therefore made two different composites of laminate-metal and laminate-metal-laminate of carbon fiber-reinforced polymer and aluminum with an ALCLAD layer. The samples were characterized by salt fog (0, 48, and 96 h) at 5 wt% NaCl and electrochemical impedance spectroscopy (EIS) with an electrolyte of 3.5 wt% NaCl. All samples were studied by electron scanning microscopy (SEM). The results demonstrated that the samples of laminate-metal-laminate presented an adsorption process after 0 and 48 h of salt fog exposition; meanwhile, the samples of laminate-metal showed a capacitive behavior for all the samples; however, corrosion resistance decreased when the salt fog exposition time increased

    MASTREE+: Time-series of plant reproductive effort from six continents.

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    Significant gaps remain in understanding the response of plant reproduction to environmental change. This is partly because measuring reproduction in long-lived plants requires direct observation over many years and such datasets have rarely been made publicly available. Here we introduce MASTREE+, a data set that collates reproductive time-series data from across the globe and makes these data freely available to the community. MASTREE+ includes 73,828 georeferenced observations of annual reproduction (e.g. seed and fruit counts) in perennial plant populations worldwide. These observations consist of 5971 population-level time-series from 974 species in 66 countries. The mean and median time-series length is 12.4 and 10 years respectively, and the data set includes 1122 series that extend over at least two decades (≥20 years of observations). For a subset of well-studied species, MASTREE+ includes extensive replication of time-series across geographical and climatic gradients. Here we describe the open-access data set, available as a.csv file, and we introduce an associated web-based app for data exploration. MASTREE+ will provide the basis for improved understanding of the response of long-lived plant reproduction to environmental change. Additionally, MASTREE+ will enable investigation of the ecology and evolution of reproductive strategies in perennial plants, and the role of plant reproduction as a driver of ecosystem dynamics

    Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 12

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 12, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

    Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 13

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público. El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 13, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR) - Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTFAG) - Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kléber Ramírez (UPTM) - Mérida - Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (CABBOPP) - Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE) - Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia – Venezuela; Centro de Investigaciones Internacionales SAS (CEDINTER) - Antioquia – Colombia y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

    Gestión del conocimiento. Perspectiva multidisciplinaria. Volumen 17

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 17 de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro es una publicación internacional, seriada, continua, arbitrada, de acceso abierto a todas las áreas del conocimiento, orientada a contribuir con procesos de gestión del conocimiento científico, tecnológico y humanístico. Con esta colección, se aspira contribuir con el cultivo, la comprensión, la recopilación y la apropiación social del conocimiento en cuanto a patrimonio intangible de la humanidad, con el propósito de hacer aportes con la transformación de las relaciones socioculturales que sustentan la construcción social de los saberes y su reconocimiento como bien público
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