Examinando por Materia "Energy dissipation"
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Ítem Designed for resistance to puncture: The dynamic response of fish scales(ELSEVIER SCIENCE BV, 2019-01-01) Ghods S.; Murcia S.; Ossa E.A.; Arola D.; Ghods S.; Murcia S.; Ossa E.A.; Arola D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaNatural dermal armors are serving as a source of inspiration in the pursuit of “next-generation” structural materials. Although the dynamic strain response of these materials is arguably the most relevant to their performance as armors, limited work has been performed in this area. Here, uniaxial tension and transverse puncture tests were performed on specimens obtained from the scales of Asian carp over strain rates spanning seven decades, from 10-4 to 103 s-1. The importance of anatomical variations was explored by comparing the performance of scales from the head, middle and tail regions. In both loading orientations, the scales exhibited a significant increase in the resistance to failure with loading rate. The rate sensitivity was substantially higher for transverse loading than for in-plane tension, with average strain rate sensitivity exponents for measures of the toughness of 0.35 and 0.08, respectively. Spatial variations in the properties were largest in the puncture responses, and scales from the head region exhibited the greatest resistance to puncture overall. The results suggest that the layered microstructure of fish scales is most effective at resisting puncture, rather than in-plane tension, and its effectiveness increases with rate of loading. X-ray microCT showed that delamination of plies in the internal elasmodine and stretching of the fibrils were key mechanisms of energy dissipation in response to puncture loading. Understanding contributions from the microstructure to this behavior could guide the development of flexible engineered laminates for penetration resistance and other related applications. © 2018 Elsevier LtdÍtem Nature-Inspired Protecto-Flexible Impact-Tolerant Materials(Wiley-VCH Verlag, 2020-01-01) Estrada, S.; Ossa, A.; Estrada, S.; Ossa, A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThe search for impact-tolerant, light-weight flexible materials has challenged materials scientists and engineers for decades. In this quest, many researchers have focused on studying natural armor as a guide to propose bioinspired materials with enhanced properties. The energy dissipation and flexibility mechanisms activated at different hierarchical structural levels of natural systems are used here as a guide to improve the energy and flexibility of synthetic materials. In particular, fish scales and osteoderms are selected as proper biological models to develop a novel family of cost-effective bioinspired protecto-flexible (Pf) materials. Furthermore, a bullet-proof protecto-flexible prototype is manufactured and tested. The ballistic tests suggest that under real stringent conditions, the system is capable of absorbing high levels of energy while remaining flexible enough to allow movement to the user. Remarkably, the material system developed allows its implementation into realistic high volumes of production with low added costs. Consequently, the proposed strategy for developing bioinspired Pf materials will enable the development of the next generation of high-performance impact-resistant materials. © 2020 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimÍtem The role of volumetric power input in the growth, morphology, and production of a recombinant glycoprotein by Streptomyces lividans in shake flasks(ELSEVIER SCIENCE BV, 2014-09-15) Marin-Palacio, Luz D.; Gamboa-Suasnavart, Ramses A.; Valdez-Cruz, Norma A.; Servin-Gonzalez, Luis; Soledad Cordova-Aguilar, Ma.; Soto, Enrique; Kloeckner, Wolf; Buechs, Jochen; Trujillo-Roldan, Mauricio A.; Marin-Palacio, Luz D.; Gamboa-Suasnavart, Ramses A.; Valdez-Cruz, Norma A.; Servin-Gonzalez, Luis; Soledad Cordova-Aguilar, Ma.; Soto, Enrique; Kloeckner, Wolf; Buechs, Jochen; Trujillo-Roldan, Mauricio A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)The impact of flask geometry on Streptomyces lividans growth and morphology, production and O-mannosylation of a recombinant O-glycoprotein (APA from Mycobacterium tuberculosis) was described and associated to the evolution of the volumetric power input (P/V) in three shake flask geometries. During the exponential growth, the highest P/V was found in baffled flasks (BF) with 0.51kW/m3, followed by coiled flasks (CF) with 0.44kW/m3 and normal Erlenmeyer flasks (NF) with 0.20kW/m3 (flasks volume of 250mL, filling with 50mL and agitated at 150rpm). During the stationary phase, P/V decreased 20% in BF and CF, but increased two times in NF, surely due to changes in mycelial morphology and its effects on rheology. Also, NF cultures were carried out at a filling volume and agitation of 15mL, 150rpm (15mL-NF), and 25mL, 168rpm (25mL-NF), in order to raise P/V closely to the values obtained in CF. However, different growth, morphology and recombinant protein productivity were obtained. These data indicate that P/V is not a definitive parameter that can determine bacteria growth and morphology, not even glycoprotein production. But it can be proposed that the oxygen transfer in the center of the pellets and hydromechanical stress might be the more relevant parameters than P/V. © 2014 Elsevier B.V.Ítem The role of volumetric power input in the growth, morphology, and production of a recombinant glycoprotein by Streptomyces lividans in shake flasks(ELSEVIER SCIENCE BV, 2014-09-15) Marin-Palacio, Luz D.; Gamboa-Suasnavart, Ramses A.; Valdez-Cruz, Norma A.; Servin-Gonzalez, Luis; Soledad Cordova-Aguilar, Ma.; Soto, Enrique; Kloeckner, Wolf; Buechs, Jochen; Trujillo-Roldan, Mauricio A.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)The impact of flask geometry on Streptomyces lividans growth and morphology, production and O-mannosylation of a recombinant O-glycoprotein (APA from Mycobacterium tuberculosis) was described and associated to the evolution of the volumetric power input (P/V) in three shake flask geometries. During the exponential growth, the highest P/V was found in baffled flasks (BF) with 0.51kW/m3, followed by coiled flasks (CF) with 0.44kW/m3 and normal Erlenmeyer flasks (NF) with 0.20kW/m3 (flasks volume of 250mL, filling with 50mL and agitated at 150rpm). During the stationary phase, P/V decreased 20% in BF and CF, but increased two times in NF, surely due to changes in mycelial morphology and its effects on rheology. Also, NF cultures were carried out at a filling volume and agitation of 15mL, 150rpm (15mL-NF), and 25mL, 168rpm (25mL-NF), in order to raise P/V closely to the values obtained in CF. However, different growth, morphology and recombinant protein productivity were obtained. These data indicate that P/V is not a definitive parameter that can determine bacteria growth and morphology, not even glycoprotein production. But it can be proposed that the oxygen transfer in the center of the pellets and hydromechanical stress might be the more relevant parameters than P/V. © 2014 Elsevier B.V.Ítem Seismic response of three-dimensional rockfill dams using the Indirect Boundary Element Method(IOP PUBLISHING LTD, 2014-01-01) Sánchez-Sesma, F.J.; Arellano-Guzmán, M.; Pérez-Gavilán, J.J.; Suarez, M.; Marengo-Mogollón, H.; Chaillat, S.; Jaramillo, J.D.; Gómez, J.; Iturrarán-Viveros, U.; Rodríguez-Castellanos, A.; Sánchez-Sesma, F.J.; Arellano-Guzmán, M.; Pérez-Gavilán, J.J.; Suarez, M.; Marengo-Mogollón, H.; Chaillat, S.; Jaramillo, J.D.; Gómez, J.; Iturrarán-Viveros, U.; Rodríguez-Castellanos, A.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Mecánica AplicadaThe Indirect Boundary Element Method (IBEM) is used to compute the seismic response of a three-dimensional rockfill dam model. The IBEM is based on a single layer integral representation of elastic fields in terms of the full-space Green function, or fundamental solution of the equations of dynamic elasticity, and the associated force densities along the boundaries. The method has been applied to simulate the ground motion in several configurations of surface geology. Moreover, the IBEM has been used as benchmark to test other procedures. We compute the seismic response of a three-dimensional rockfill dam model placed within a canyon that constitutes an irregularity on the surface of an elastic half-space. The rockfill is also assumed elastic with hysteretic damping to account for energy dissipation. Various types of incident waves are considered to analyze the physical characteristics of the response: symmetries, amplifications, impulse response and the like. Computations are performed in the frequency domain and lead to time response using Fourier analysis. In the present implementation a symmetrical model is used to test symmetries. The boundaries of each region are discretized into boundary elements whose size depends on the shortest wavelength, typically, six boundary segments per wavelength. Usually, the seismic response of rockfill dams is simulated using either finite elements (FEM) or finite differences (FDM). In most applications, commercial tools that combine features of these methods are used to assess the seismic response of the system for a given motion at the base of model. However, in order to consider realistic excitation of seismic waves with different incidence angles and azimuth we explore the IBEM. © 2010 IOP Publishing Ltd.