Design of the improvement cycle in Prevention Engineering of Occupational Risk

El Ciclo de Mejora en el Aula (CIMA) se ha realizado en la asignatura de ingeniería de la prevención de riesgos laborales (IPRL), impartida en el grado en ingeniería mecánica en la Escuela Politécnica Superior en el primer cuatrimestre del curso académico 2021-2022. La extensión del CIMA es de 12 horas y el número de alumnos que han participado ha estado entorno a 60 (siendo 94 los matriculados). El hecho de comenzar la asignatura con el CIMA ha sido muy positivo y los resultados muestran unos grandes avances en las escaleras de aprendizaje. Esto indica que el diseño de las sesiones fue acertado y que se generó un ambiente en clase que propició un aprendizaje adecuado entre el estudiantado.The Cycle of Improvement in the Classroom (CIMA) has been carried out in the subject of engineering of the prevention of occupational risks (IPRL), taught in the degree in mechanical engineering at the Higher Polytechnic School in the first semester of the academic year 2021-2022. The extension of the CIMA is 12 hours and the number of students who have participated has been around 60 (being 94 enrolled). The fact of starting the subject with the CIMA has been very positive and the results show great advances in the learning ladders. This indicates that the design of the sessions was successful and that a classroom environment was created that fostered adequate learning among the students

Implementación de la gestión de riesgos al procedimiento de facturación en G4S Cash Solutions Colombia Ltda.

93 páginasProject designed with the main objective of defining a methodology, which will allow to control and minimize the risks associated in the billing process at the G4s Cash Solutions Colombia Ltda., the development of this project by la proyecía y aya directives, to make the decision to implement this methodology in a way that helps to improve the development of the processes related to the billing process, in order to avoid reprocesses in each of them and responding to the times of response. And especially in the generation of billing, avoiding to minimize the risks that may be present.Proyecto diseñado con el objetivo principal de definir una metodología, la cual permitirá controlar y minimizar los riesgos asociados en el proceso de facturación en la transportadora de valores G4S Cash Solutions Colombia Ltda., la elaboración de este proyecto de grado ayudara a la compañía y a sus directivos, a tomar la decisión de la implementación de esta metodología de manera que ayude a mejorar el desarrollo de los procesos relacionados al proceso de facturación, con el fin de evitar reprocesos en cada uno de ellos y mejorar en los tiempos de respuesta ante el cliente y en especial en la generación de la facturación evitando así minimizar los riesgos que se puedan presentar.Magíster en Gestión Integral del RiesgoMaestrí

Microstructural and XRD analysis and study of the properties of the system Ti-TiAl-B4C processed under different operational conditions

High specific modulus materials are considered excellent for the aerospace industry. The system Ti-TiAl-B4C is presented herein as an alternative material. Secondary phases formed in situ during fabrication vary depending on the processing conditions and composition of the starting materials. The final behaviors of these materials are therefore difficult to predict. This research focuses on the study of the system Ti-TiAl-B4C, whereby relations between microstructure and properties can be predicted in terms of the processing parameters of the titanium matrix composites (TMCs). The powder metallurgy technique employed to fabricate the TMCs was that of inductive hot pressing (iHP) since it offers versatility and flexibility. The short processing time employed (5 min) was set in order to test the temperature as a major factor of influence in the secondary reactions. The pressure was also varied. In order to perform this research, not only were X-Ray Diffraction (XRD) analyses performed, but also microstructural characterization through Scanning Electron Microscopy (SEM). Significant results showed that there was an inflection temperature from which the trend to form secondary compounds depended on the starting material used. Hence, the addition of TiAl as an elementary blend or as prealloyed powder played a significant role in the final behavior of the TMCs fabricated, where the prealloyed TiAl provides a better precursor of the formation of the reinforcement phases from 1100 °C regardless of the pressur

In Situ Titanium Composites: XRD Study of Secondary Phases Tied to the Processing Conditions and Starting Materials

Nowadays, the development of high specific modulus materials involves studies of new materials and novel manufacturing routes. From the point of view of composite materials, titanium composites (TMCs) have been long studied for their interesting properties, as a result of the conjunction of low-density and high mechanical properties, as well as corrosion resistance. Among various processing techniques, the in situ reinforced method shows many advantages above the rest. The reactions between matrix and reinforcement drive up the final properties of TMCs. Varying the processing conditions, in addition to reinforcement type and content, significant variations are expected in TMCs’ behaviour. In this regard, the present study draws on previous author works. The specimens studied were manufactured by hot consolidation processes, inductive hot pressing (iHP) and direct hot pressing (DHP), at different operational parameters and compositions. X-ray powder diffraction (XRD) investigations tied formations of secondary phases to substantive changes in TMC behaviour under the influence of the fabrication parameters

Fabricación mediante innovadoras técnicas pulvimetalúrgicas de materiales compuestos de matriz ligera

Hoy en día el interés por desarrollar nuevos materiales que satisfagan las necesidades tecnológicas, conlleva a un estudio continuo en la innovación de los procesos de fabricación. La ventaja que ofrecen las técnicas pulvimetalúrgicas de procesado en caliente convencional (HP) y directa (dHP), suponen un ahorro en tiempo que puede favorecer la viabilidad de nuevos materiales fabricados por estas técnicas El potencial que presentan en cuanto a sus propiedades los materiales compuestos de matriz de titanio (TMCs), es muy valorado por el sector aeroespacial. La gran limitación de uso de estos materiales en su aplicación en otros sectores se debe en gran medida al alto coste. La línea de investigación creada por este grupo en colaboración con la empresa austríaca RHP-Technology, promueve el estudiofabricación-caracterización de TMCs fabricados mediante técnicas pulvimetalúrgicas avanzadas de compactación en caliente. Esta colaboración ofrece la posibilidad de producir materiales a la carta desde un punto de vista pulvimetalúrgico. Los materiales estudiados principalmente son materiales compuestos de matriz titanio (TMCs) reforzados con partículas cerámicas como son el boro amorfo (B), el carburo de boro (B4C) y el diboruro de titanio (TiB2), con el objetivo de promover reacciones entre la matriz de titanio y las partículas de cerámicos que consoliden nuevos compuestos que actúan reforzando la matriz in situ.Nowadays, the interest in developing novel materials to achieve the technological needs, leads to an ongoing study on innovation of manufacturing processes. The advantages of conventional Hot Pressing technique (HP) and direct Hot Pressing (dHP) involve savings in time in order to promote the viability of new materials manufactured by hot consolidation processes. Titanium Metal matrix Composites (TMCs) offer interesting properties, which are highly valued by the aerospace sector. However, there are some use limitations of these materials in other sectors due to their high cost. The research created by this group in collaboration with the Austrian research-company RHP-Technology, promotes the study-manufacturingcharacterization of these TMCs. This collaboration provides the possibility of manufacturing materials “à la carte” from a point of view of Powder Metallurgy (PM). The materials studied are primarily TMCs reinforced with ceramic particles as boron amorphous (B), boron carbide (B4C) and titanium diboride (TiB2). By the addition of these ceramic materials to the matrix, in situ reactions between the matrix and the ceramic reinforcement are expected. In this respect, the titanium matrix becomes reinforced

Influence of nano-reinforcements on the mechanical properties and microstructure of titanium matrix composites

The goal of this work is the evaluation of nanoscaled reinforcements; in particular nanodiamonds (NDs) and carbon nanotubes (CNTs) on properties of titanium matrix composites (TiMMCs). By using nano sized materials as reinforcement in TiMMCs, superior mechanical and physical properties can be expected. Additionally, titanium powder metallurgy (P/M) offers the possibility of changing the reinforcement content in the matrix within a very wide range. In this work, TiMMCs have been produced from titanium powder (Grade 4). The manufacturing of the composites was done by hot pressing, followed by the characterisation of the TiMMCs. The Archimedes density, hardness and oxygen content of the specimens in addition to the mechanical properties were compared and reported in this work. Moreover, XRD analysis and SEM observations revealed in situ formed titanium carbide (TiC) phase after hot pressing in TiMMCs reinforced with NDs and CNTs, at 900 °C and 1100 °C respectively. The strengthening effect of NDs was more significant since its distribution was more homogeneous in the matrix

Estado nutricional de los pacientes con diagnóstico de Niemann-Pick tipo C en Colombia

Niemann Pick type C disease is a neurovisceral disease of progressive and debilitating lysosomal deposit whose symptoms have a negative impact on the nutritional status of people who suffer from it. In addition to the above, severe gastrointestinal complications have been described with the use of Miglustat, the treatment of choice for this disease, which could increase the nutritional risk of these patients.La enfermedad de Niemann Pick tipo C, es una enfermedad neurovisceral de depósito lisosomal progresiva y debilitante cuyos síntomas tienen un impacto negativo en el estado nutricional de las personas que lo padecen. Sumado a lo anterior, se han descrito complicaciones gastrointestinales severas con el uso de Miglustat, tratamiento de elección para esta enfermedad, lo cual podría incrementar el riesgo nutricional de estos pacientes

Designing, processing and characterisation of titanium cylinders with graded porosity: An alternative to stress-shielding solutions

Bone resorption events and consequent failure of titanium implants are frequently related to stress-shielding problems, due to stiffness mismatch with respect to bone. This is a mechanical incompatibility problem, which is difficult to resolve because of the challenge of replacing highly anisotropic biomechanical systems, as is the case of dental implants. This work describes the designing, processing and characterisation of cylindrical titanium samples with a longitudinally graded porosity obtained by conventional powder-metallurgy techniques. The design concept used was biomimetic, based on the stiffness properties of the tissues to be in contact with titanium dental implants. Processing conditions were optimised in terms of different parameters: structural integrity, porosity and mechanical properties. The influence of sintering temperature was evaluated in search of optimum results under the above criteria. The behaviour of longitudinal porosity and Young’s modulus were consistent with the preliminary design concept from the original biomechanical system. Mechanical strength results were reasonably suitable for dental applications and they were favourably sensitive to increasing sintering temperature, due to a stronger adhesion between initial green layers of cylindrical samples. Results showed that it is possible to obtain a desired longitudinal gradient in Young’s modulus, as well as suitable yield strength values. The optimised processing described suggests that it is a plausible candidate for manufacturing dental implants with a good balance between reduced stress shielding and suitable mechanical strength, which encourages us to undertake further work along the same lines.Ministerio de Economía y Competitividadt MAT2010- 2085

Estudio comparativo del comportamiento de diversos materiales de refuerzo en matrices de titanio fabricados mediante compactación por sinterización rápida

Regarding titanium matrix composites (TMCs), their properties strongly depend on the reinforcement material employed for their manufacturing; this may lead to a multitude of investigations on TMCs. Considering the diverse typology of the reinforcement, six types of ceramic particles were tested in this investigation: B₄C, SiB₆ , TiB₂ , TiC, TiN, and BN. In order to compare their behaviour and their own influence on the properties of the TMCs, the same ratio was employed in the starting materials, 30% volume. Among the techniques for developing TMCs, a significant number of authors propose Powder Metallurgy as a favourable route. In this framework, the novel Rapid Sinter Pressing technique was employed to perform the present study, due to its flexibility, repeatability, and reproducibility, as well as short-run cycle times. The processing temperature (930 °C) was set with the intention of evaluating how the reinforcements behave differently depending on their reactivity with the Ti matrix. In this regard, the main objective of the research was to carry out a comparison on the behaviour of seven TMCs fabricated with similar operational parameters via RSP.En cuanto a los materiales compuestos de base titanio (TMC), sus propiedades dependen en gran medida del material de refuerzo empleado para su fabricación; dando lugar a una gran diversidad de investigaciones sobre los TMCs. Considerando la diversa tipología del refuerzo, en este estudio se trabajó con seis tipos de partículas cerámicas: B₄C, SiB₆,TiB₂ , TiC, TiN y BN. Para poder comparar su comportamiento e influencia sobre las propiedades de los TMCs, se empleó siempre la misma proporción con respecto al material de partida, 30% en volumen. Entre las técnicas que se conocen para desarrollar TMCs, la pulvimetalurgia ha sido propuesta como una vía favorable por un número significativo de autores. En este marco, para la realización del presente estudio, se utilizó la novedosa técnica Rapid Sinter Pressing, debido a su flexibilidad, repetibilidad y reproducibilidad, así como a sus reducidos tiempos de ciclo. La temperatura de procesamiento (930 °C) se estableció con la intención de evaluar cómo los refuerzos afectan de diferente manera, en función de su reactividad con la matriz de Ti. En este sentido, el objetivo principal de esta investigación ha sido realizar una comparativa del comportamiento de siete TMCs fabricados vía de Compactación por Sinterización Rápida (Rapid Sinter Pressing) bajo las mismas condiciones de procesado.Universidad de Sevilla VI PPIT-2020-I.

Porous Titanium for Biomedical Applications: Evaluation of the Conventional Powder Metallurgy Frontier and Space-Holder Technique

Titanium and its alloys are reference materials in biomedical applications because of their desirable properties. However, one of the most important concerns in long-term prostheses is bone resorption as a result of the stress-shielding phenomena. Development of porous titanium for implants with a low Young’s modulus has accomplished increasing scientific and technological attention. The aim of this study is to evaluate the viability, industrial implementation and potential technology transfer of different powder-metallurgy techniques to obtain porous titanium with stiffness values similar to that exhibited by cortical bone. Porous samples of commercial pure titanium grade-4 were obtained by following both conventional powder metallurgy (PM) and space-holder technique. The conventional PM frontier (Loose-Sintering) was evaluated. Additionally, the technical feasibility of two different space holders (NH4HCO3 and NaCl) was investigated. The microstructural and mechanical properties were assessed. Furthermore, the mechanical properties of titanium porous structures with porosities of 40% were studied by Finite Element Method (FEM) and compared with the experimental results. Some important findings are: (i) the optimal parameters for processing routes used to obtain low Young’s modulus values, retaining suitable mechanical strength; (ii) better mechanical response was obtained by using NH4HCO3 as space holder; and (iii) Ti matrix hardening when the interconnected porosity was 36–45% of total porosity. Finally, the advantages and limitations of the PM techniques employed, towards an industrial implementation, were discussed.Ministry of Economy and Competitiveness of Spain Grant MAT2015-71284-PJunta de Andalucía Grant P12-TEP-1401Comisión Nacional de Investigación, Científica y Tecnológica (CONICYT) of the Chilean government project FONDECYT 1116086