129 research outputs found
Implementación del mantenimiento autónomo a las herramientas neumáticas de la línea de ensamble de la empresa AUTECO MOBILITY SAS
Actualmente hablar de calidad no se limita solo al buen estado de los productos o servicios, esta va más allá y tiene implicaciones y procesos que son necesarios, como innovar constantemente, realizar procesos de mejora y desarrollo que permitan la eficacia y la eficiencia en la producción, con el objetivo de alcanzar la competitividad en un mercado con múltiples oferentes y un sin número de demandantes que cada vez exigen mayor calidad, por tanto, se hace indispensable que las empresas emprendan acciones para mantener y mejorar la calidad de sus productos.
Por tal motivo, este proyecto de grado pretende implementar el segundo pilar del TPM (mantenimiento productivo total); el cual consiste en la elaboración y aplicación de un plan de mantenimiento autónomo para todas las herramientas neumáticas de la principal línea de ensamble de la empresa AUTECO MOBILITY SAS; ubicada en carrera 42 no 45-77 del municipio de Itagüí. Esto con el fin de mejorar la disponibilidad, mantenibilidad y confiabilidad de dichas herramientas, además, con el objetivo de mejorar la calidad del producto terminado y la eficiencia de la red de aire comprimido a través de buenas prácticas de limpieza y lubricación.
Consecuentemente, se visualiza en este proyecto la estandarización de un plan de mantenimiento inexistente, teniendo como consecuencia un ahorro evidente en la mano de obra de mantenimiento, en la compra de pistolas, en repuestos y en el consumo de aire, a la vez se hace notorio el mejoramiento en la disponibilidad y mantenibilidad de dichos equipos.
Por lo anterior el proyecto de estandarización de un plan de mantenimiento pretende implementar buenas prácticas en el proceso, a través metodologías que posibiliten la ejecución de medidas de mejoramiento que permitan optimizar los recursos, tiempos y mejorar el proceso.
En un mundo altamente competitivo la implementación de estrategias como el TPM más allá de ser una buena práctica, se convierte en una necesidad, en este sentido la prevención, el mejoramiento continuo y la búsqueda de la calidad son un requisito que la industria reclama actualmente, por lo cual el presente trabajo propende por responder a dicha necesidad.Ingeniero de Telecomunicacionespregrad
Regeneración vía embriogénesis somática de una variedad colombiana élite de theobroma cacao l.
Título en ingles: Regeneration through somatic embryogenesis of an elite colombian Theobroma cacao L. variety El objetivo de esta investigación fue evaluar dos protocolos de propagación vía embriogénesis somática a partir de explantes florales en dos clones élite BIOB e ICS95 de Theobroma cacao L. Se obtuvo un 50 y 32% de callo embriogénico en ICS95 y BIOB respectivamente con el protocolo de Fontanel et al. (2002), modificado después de un periodo de cultivo de tres meses. Los embriones pasaron por fases que se correspondieron con medios de cultivo diferenciales: Inducción, Formación, Maduración y Mantenimiento. Para la embriogénesis somática secundaria se obtuvo un 23% de embriones a partir de embriones somáticos primarios en un medio, conteniendo 1mg/L de 2,4,5 T (2,4,5 Triclorofenoxiacético). Se logró, además, desarrollar enraizamiento adventicio aplicando pulsos de IBA (Ácido Indol Butírico) a 0.5mg/L y 0.5g/L durante un minuto. Las plantas enraizadas se llevaron a una mezcla de tierra: arena (1:1) para su adaptación ex vitro, obteniéndose un 66% de plantas aclimatadas. Los estudios histológicos mostraron diferentes características típicas del desarrollo embriogénico. Este es el primer reporte en el que se logra de manera exitosa la conversión hasta plántula (68%) y la adaptación ex vitro de una variedad colombiana de cacao vía embriogénesis somática primaria y secundaria. Palabras clave: Cacao; embriones somáticos; propagación in vitro; cultivo de tejidos. Abstract: In this research we evaluate two protocols of propagation via somatic embryogenesis from floral explants using two elite clones BIOB and ICS95 of Theobroma cacao L. We obtained 50 and 32% of embryogenic callus on ICS95 and BIOB respectively with Fontanel et al., (2002) protocol modified after three months of culture. The embryos went through four phases; Induction, Formation, Maduration and Mantenimiento which corresponded each one with different media culture. For secondary somatic embryogenesis we obtained 23% of embryos from primary somatic embryos in a medium with 1mg/L of 2,4,5 T (2,4,5 Triclorofenoxiacetic). Also we obtained plants that developed new roots applying pulses with IBA (Indol Butiric Acid) 0.5mg/L and 0.5g/L for a minute. The developed plants were moved to a mix of potting soil and sand (1:1) for their ex vitro adaptation, getting 66% of acclimatized plants. The histological analysis showed the typical characteristics of the embryogenic development. This is the first report where it is achieved the successful conversion to plantlets (68%) and ex vitro adaptation of a colombian cocoa variety via primary and secondary embryogenesis. Key words: Cacao; somatic embryos; in vitro propagation; tissue culture
Polyphenols distributions and reserve substances analysis in cacao somatic embryogenesis
In order to understand the causes of lack of regeneration in cacao somatic embryos, two cacao varieties with different responses to regeneration potential were described based on their capacity to store different compounds. It is well known that seed reserves play a central role in the regenerative capability of somatic embryos; thus, we followed histochemical changes and reserve fluctuations of proteins, polysaccharides and polyphenols during somatic embryogenesis (SE) in the two cacao varieties. The study showed that, in somatic embryos of the regenerating variety, polyphenols were localized mainly in the periphery of the embryo (epidermal cells) and proteins were the main storage substance in the embryo expression medium, while the non-regenerating variety had a high presence of polysaccharides with random distribution of polyphenols at the end of the embryo induction step.Dos variedades de cacao con diferentes respuestas a la regeneración fueron descritas en función de su capacidad para almacenar diferentes compuestos, con el fin de aproximarse al entendimiento de las causas de la falta de regeneración en embriones somáticos de cacao. Es bien sabido que las reservas de semillas desempeñan un papel central en la capacidad de regeneración de embriones somáticos; por tanto, se realizó un seguimiento de cambios histoquímicos y fluctuaciones de reserva de proteínas, polisacáridos y polifenoles durante la embriogénesis somática (SE) en dos variedades de cacao. El estudio mostró que, en los embriones somáticos de la variedad regenerante, los polifenoles se localizaron principalmente en la periferia del embrión (células de la epidermis) y las proteínas fueron el componente principal de almacenamiento en el medio de expresión de embriones, mientras que la variedad no regenerante tenía una alta presencia de polisacáridos y una distribución aleatoria de los polifenoles en el final de la etapa de inducción de embriones
Ecotoxicity testing and environmental risk assessment of iron nanomaterials for sub-surface remediation – Recommendations from the FP7 project NanoRem
The “movimiento independiente de renovación absoluta” (independent absolute renovation movement) and the production of religious incentives for political action in Manizales, Colombia.
En este escrito se analiza la producción de incentivos para la movilización política de un grupo de candidatos  al  Concejo de la ciudad de Manizales en 2011. Para ello se revisa la dinámica del campo y el mercado político  en el cual se movilizaron, un conjunto de cualidades objetivas en contraste con el total de los candidatos (151) de ese  episodio electoral, en relación con las cualidades subjetivas y las producciones discursivas de algunos de ellos.  Con esta estrategia se trata de hacer comprensibles las diferencias en la formación de las carreras políticas en  relación con las dinámicas espacio-temporales del mercado político y de los procesos de reorganización de los  ordenamientos jurídico-políticos. In this writing the production of incentivesfor political mobilization of a group of candidates to the City Council  of Manizales in 2011 is analyzed. For this purpose, the dynamics in the field and the political market where they  moved areanalyzed as well as a group of objective qualities in contrast withthe total candidates (151) of that  polling episode regarding subjective qualities and discursive productions of some of them. With such strategy,  it is intended to make understandable the differences in the formation of political careers concerning spatial- temporaldynamics of the political market and the reorganization processes of the legal and political regulation
The “movimiento independiente de renovación absoluta” (independent absolute renovation movement) and the production of religious incentives for political action in Manizales, Colombia.
En este escrito se analiza la producción de incentivos para la movilización política de un grupo de candidatos  al  Concejo de la ciudad de Manizales en 2011. Para ello se revisa la dinámica del campo y el mercado político  en el cual se movilizaron, un conjunto de cualidades objetivas en contraste con el total de los candidatos (151) de ese  episodio electoral, en relación con las cualidades subjetivas y las producciones discursivas de algunos de ellos.  Con esta estrategia se trata de hacer comprensibles las diferencias en la formación de las carreras políticas en  relación con las dinámicas espacio-temporales del mercado político y de los procesos de reorganización de los  ordenamientos jurídico-políticos. In this writing the production of incentivesfor political mobilization of a group of candidates to the City Council  of Manizales in 2011 is analyzed. For this purpose, the dynamics in the field and the political market where they  moved areanalyzed as well as a group of objective qualities in contrast withthe total candidates (151) of that  polling episode regarding subjective qualities and discursive productions of some of them. With such strategy,  it is intended to make understandable the differences in the formation of political careers concerning spatial- temporaldynamics of the political market and the reorganization processes of the legal and political regulation
Experiment design and bacterial abundance control extracellular H2O2 concentrations during four series of mesocosm experiments
The extracellular concentration of H2O2 in surface aquatic environments is controlled by a balance between photochemical production and the microbial synthesis of catalase and peroxidase enzymes to remove H2O2 from solution. In any kind of incubation experiment, the formation rates and equilibrium concentrations of reactive oxygen species (ROSs) such as H2O2 may be sensitive to both the experiment design, particularly to the regulation of incident light, and the abundance of different microbial groups, as both cellular H2O2 production and catalase–peroxidase enzyme production rates differ between species. Whilst there are extensive measurements of photochemical H2O2 formation rates and the distribution of H2O2 in the marine environment, it is poorly constrained how different microbial groups affect extracellular H2O2 concentrations, how comparable extracellular H2O2 concentrations within large-scale incubation experiments are to those observed in the surface-mixed layer, and to what extent a mismatch with environmentally relevant concentrations of ROS in incubations could influence biological processes differently to what would be observed in nature. Here we show that both experiment design and bacterial abundance consistently exert control on extracellular H2O2 concentrations across a range of incubation experiments in diverse marine environments.
During four large-scale (>1000 L) mesocosm experiments (in Gran Canaria, the Mediterranean, Patagonia and Svalbard) most experimental factors appeared to exert only minor, or no, direct effect on H2O2 concentrations. For example, in three of four experiments where pH was manipulated to 0.4–0.5 below ambient pH, no significant change was evident in extracellular H2O2 concentrations relative to controls. An influence was sometimes inferred from zooplankton density, but not consistently between different incubation experiments, and no change in H2O2 was evident in controlled experiments using different densities of the copepod Calanus finmarchicus grazing on the diatom Skeletonema costatum (<1 % change in [H2O2] comparing copepod densities from 1 to 10 L−1). Instead, the changes in H2O2 concentration contrasting high- and low-zooplankton incubations appeared to arise from the resulting changes in bacterial activity. The correlation between bacterial abundance and extracellular H2O2 was stronger in some incubations than others (R2 range 0.09 to 0.55), yet high bacterial densities were consistently associated with low H2O2. Nonetheless, the main control on H2O2 concentrations during incubation experiments relative to those in ambient, unenclosed waters was the regulation of incident light. In an open (lidless) mesocosm experiment in Gran Canaria, H2O2 was persistently elevated (2–6-fold) above ambient concentrations; whereas using closed high-density polyethylene mesocosms in Crete, Svalbard and Patagonia H2O2 within incubations was always reduced (median 10 %–90 %) relative to ambient waters
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POZylation: a new approach to enhance nanoparticle diffusion through mucosal barriers
The increasing use of nanoparticles in the pharmaceutical industry is generating concomitant interest in developing nanomaterials that can rapidly penetrate into, and permeate through, biological membranes to facilitate drug delivery and improve the bioavailability of active pharmaceutical ingredients. Here, we demonstrate that the permeation of thiolated silica nanoparticles through porcine gastric mucosa can be significantly enhanced by their functionalization with either 5 kDa poly(2-ethyl-2-oxazoline) or poly(ethylene glycol). Nanoparticle diffusion was assessed using two independent techniques; Nanoparticle Tracking Analysis, and fluorescence microscopy. Our results show that poly(2-ethyl-2-oxazoline) and poly(ethylene glycol) have comparable abilities to enhance diffusion of silica nanoparticles in mucin dispersions and through the gastric mucosa. These findings provide a new strategy in the design of nanomedicines, by surface modification or nanoparticle core construction, for enhanced transmucosal drug delivery
Fe(II) stability in coastal seawater during experiments in Patagonia, Svalbard, and Gran Canaria
The speciation of dissolved iron (DFe) in the ocean is widely assumed to consist almost exclusively of Fe(III)-ligand complexes. Yet in most aqueous environments a poorly defined fraction of DFe also exists as Fe(II), the speciation of which is uncertain. Here we deploy flow injection analysis to measure in situ Fe(II) concentrations during a series of mesocosm/microcosm/multistressor experiments in coastal environments in addition to the decay rate of this Fe(II) when moved into the dark. During five mesocosm/microcosm/multistressor experiments in Svalbard and Patagonia, where dissolved (0.2 µm) Fe and Fe(II) were quantified simultaneously, Fe(II) constituted 24 %–65 % of DFe, suggesting that Fe(II) was a large fraction of the DFe pool. When this Fe(II) was allowed to decay in the dark, the vast majority of measured oxidation rate constants were less than calculated constants derived from ambient temperature, salinity, pH, and dissolved O2. The oxidation rates of Fe(II) spikes added to Atlantic seawater more closely matched calculated rate constants. The difference between observed and theoretical decay rates in Svalbard and Patagonia was most pronounced at Fe(II) concentrations <2 nM, suggesting that the effect may have arisen from organic Fe(II) ligands. This apparent enhancement of Fe(II) stability under post-bloom conditions and the existence of such a high fraction of DFe as Fe(II) challenge the assumption that DFe speciation in coastal seawater is dominated by ligand bound-Fe(III) species
Heteroaggregation of nanoparticles with biocolloids and geocolloids
The application of nanoparticles has raised concern over the safety of these materials to human health and the ecosystem. After release into an aquatic environment, nanoparticles are likely to experience heteroaggregation with biocolloids, geocolloids, natural organic matter (NOM) and other types of nanoparticles. Heteroaggregation is of vital importance for determining the fate and transport of nanoparticles in aqueous phase and sediments. In this article, we review the typical cases of heteroaggregation between nanoparticles and biocolloids and/or geocolloids, mechanisms, modeling, and important indicators used to determine heteroaggregation in aqueous phase. The major mechanisms of heteroaggregation include electric force, bridging, hydrogen bonding, and chemical bonding. The modeling of heteroaggregation typically considers DLVO, X-DLVO, and fractal dimension. The major indicators for studying heteroaggregation of nanoparticles include surface charge measurements, size measurements, observation of morphology of particles and aggregates, and heteroaggregation rate determination. In the end, we summarize the research challenges and perspective for the heteroaggregation of nanoparticles, such as the determination of αhetero values and heteroaggregation rates; more accurate analytical methods instead of DLS for heteroaggregation measurements; sensitive analytical techniques to measure low concentrations of nanoparticles in heteroaggregation systems; appropriate characterization of NOM at the molecular level to understand the structures and fractionation of NOM; effects of different types, concentrations, and fractions of NOM on the heteroaggregation of nanoparticles; the quantitative adsorption and desorption of NOM onto the surface of nanoparticles and heteroaggregates; and a better understanding of the fundamental mechanisms and modeling of heteroaggregation in natural water which is a complex system containing NOM, nanoparticles, biocolloids and geocolloids
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