96 research outputs found

    Design for Additive Manufacturing: Tool Review and a Case Study

    Get PDF
    This paper aims to collect in a structured manner different computer-aided engineering (CAE) tools especially developed for additive manufacturing (AM) that maximize the capabilities of this technology regarding product development. The flexibility of the AM process allows the manufacture of highly complex shapes that are not possible to produce by any other existing technology. This fact enables the use of some existing design tools like topology optimization that has already existed for decades and is used in limited cases, together with other novel developments like lattice design tools. These two technologies or design approaches demand a highly flexible manufacturing system to be applied and could not be used before, due to the conventional industrial process limitations. In this paper, these technologies will be described and combined together with other generic or specific design tools, introducing the study case of an additive manufactured mechanical design of a bicycle stem

    Basalt Fiber Composites with Reduced Thermal Expansion for Additive Manufacturing

    Get PDF
    Fused filament fabrication (FFF) is gaining attention as an efficient way to create parts and replacements on demand using thermoplastics. This technology requires the development of new materials with a reliable printability that satisfies the requirement of final parts. In this context, a series of composites based on acrylonitrile styrene acrylate (ASA) reinforced with basalt fiber (BF) are reported in this work. First, several surface modification treatments are applied onto the BF to increase their compatibility with the ASA matrix. Then, once the best treatment is identified, the mechanical properties, coefficient of thermal expansion (CTE) and warping distortion of the different specimens designed and prepared by FFF are studied. It was found that the silanized BF is appropriate for an adequate printing, obtaining composites with higher stiffness, tensile strength, low CTE and a significant reduction in part distortion. These composites are of potential interest in the design and manufacturing of final products by FFF, as they show much lower CTE values than pure ASA, which is essential to successfully fabricate large objects using this technique

    Product Design by Additive Manufacturing for Water Environments: Study of Degradation and Absorption Behavior of PLA and PETG

    Get PDF
    Additive manufacturing technologies are shifting from rapid prototyping technologies to end use or final parts production. Polymeric material extrusion processes have been broadly addressed with a specific definition of all parameters and variables for all different of technologies approaches and materials. Recycled polymeric materials have been studied due to the growing importance of the environmental awareness of the contemporary society. Beside this, little specific research has been found in product development applications for AM where the printed parts are in highly moisture environments or surrounded by water, but polymers have been for long used in such industries with conventional manufacturing approaches. This work focuses on the analysis and comparison of two different additively manufactured polymers printed by fused filament fabrication (FFF) processes using desktop-size printers to be applied for product design. The polymers used have been a recycled material: polyethylene terephthalate glycol (PETG) and polylactic acid (PLA). Degradation and water absorption behaviors of both materials are presented, analyzed and discussed in this paper, where different samples have been immersed in saturated solutions of water with maritime salt and sugar together with a control sample immersed in distilled water. The samples have been dimensionally and weight-controlled weekly as well as microscopically analyzed to understand degradation and absorption processes that appear in the fully saturated solutions. The results revealed how the absorption process is stabilized after a reduced number of weeks for both materials and how the degradation process is more remarked in the PLA material due to its organic nature

    Experimental and simulated study of 3D-printed couplings’ suitability for industrial application

    Get PDF
    This paper explores the possibility of applying reverse engineering to flexible coupling spare parts through additive manufacturing. Although couplings’ simplicity makes them go unnoticed, they connect elements that transmit power between two shafts, thus being an essential component for most of the machinery currently used in the industry. In this study, flexible couplings with different infill density (60% and 80%) were 3D printed by the fused filament fabrication technique. The original and the additive manufactured couplings were modelled to compare their compressive response and energy-absorbing characteristics, and experimental tests were performed to validate finite element analysis. To derive an optimal material distribution within coupling structure, a generative design approach was conducted through nTopology software. With this novel simulation-driven design, it is possible to reduce the weight of the redesigned part up to 15.8% by defining the wall thickness of the internal structure based on the results of finite element simulation, while maintaining its functionality. Moreover, an economic-environmental study was carried out. Results ensure that the 3D printed prototypes are suitable for replacing the original one under its current operating conditions. Additionally, the economic study shows that the redesigned couplings allow companies to save more than €2700 per coupling in relation to CO2 emission payments

    White Paper 4: Challenges In Biomedicine & Health

    Get PDF
    Publicado en Madrid, 231 p. ; 17 cm.A lesson that we have learned from the pandemia caused by coronavirus is that solutions in health require coordinated actions. Beside this and other emerging and re-emerging infectious diseases, millions of Europeans are suffering a plethora of disorders that are currently acquiring epidemic dimensions, including cancer, rare diseases, pain and food allergies, among others. New tools for prevention, diagnosis and treatment need to be urgently designed and implemented using new holistic and multidisciplinary approaches at three different levels (basic research, translational/clinical and public/social levels) and involving researchers, clinicians, industry and all stakeholders in the health system. The CSIC is excellently positioned to lead and coordinate these challenges in Biomedicine and Health.Peer reviewe

    Red de coordinación de la implantación del primer curso del grado en Tecnologías de la Información para la Salud

    Get PDF
    En este trabajo se ha intentado recoger las acciones que se han llevado a cabo en la coordinación de la implantación del primer curso del nuevo grado de Tecnologías de la Información para la Salud, grado con un marcado carácter multidisciplinar que condiciona la enseñanza de los contenidos. Entre estas acciones se han revisado las guías de cada asignatura participante en la red y se han realizado reuniones de seguimiento de la implantación de las asignaturas para detectar fortalezas y debilidades en el proceso docente. También se ha contado con la opinión de alumnos bien a través de encuestas bien directamente en conversaciones con los representantes del alumnado. Pretendemos que las conclusiones obtenidas tras el análisis de resultados se puedan aplicar el curso que viene y, de esta forma, avanzar en la implantación de la titulación con calidad y, especialmente, con el objetivo de formar egresados que satisfagan las necesidades de la sociedad

    Association of Candidate Gene Polymorphisms With Chronic Kidney Disease: Results of a Case-Control Analysis in the Nefrona Cohort

    Get PDF
    Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2, 445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionizationtime of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD

    El derecho del trabajo y de la seguridad social en españa en 2018

    Get PDF
    En su quinta edición, el Informe “El Derecho del Trabajo y de la Seguridad Social en España 2018” le ofrece una síntesis, que por concreta no es menos rigurosa, de los principales hitos por los que ha transitado el iuslaboralismo a lo largo del último año. En concreto, en las páginas que siguen, los expertos integrantes de la Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social (AEDTSS) analizan para usted, en primer lugar, las principales resoluciones europeas y nacionales en materia de igualad y no discriminación, acoso en sus más diversas manifestaciones, liberad religiosa y libertad de expresión. Asimismo, se abordan también las cuestiones relativas al empleo y la contratación, casi monopolizadas por el impacto de las plataformas y las consecuencias del caso de Diego. En materia de vicisitudes, sin perder importancia el despido colectivo, observará un cierto auge de los casos relativos a sucesión empresarial, movilidad funcional y empleo público. En el ámbito del derecho colectivo, además de analizarse el IV AENC, encontrará un estudio pormenorizado de las principales resoluciones en materia de libertad sindical, representación unitaria y ultraactividad. La sección relativa a conciliación y corresponsabilidad incluye este año como novedad un apartado relativo a violencia de género, al hilo de los avances normativos derivados del Real Decreto-ley 9/2018. Los epígrafes concernientes a la protección social y la prevención de riesgos laborales crecen de forma significativa en esta edición, lo que ha permitido abordar la evolución jurisprudencial para buena parte de las prestaciones y riesgos previstos en la Ley. Por último, las expertas del apartado de derecho procesal se han encargado de revisar a fondo los casos más significativos en el marco de las modalidades procesales especiales, con especial hincapié en el ámbito concursal. También han abordado la jurisprudencia constitucional más reciente sobre el de recurso de reposición. En suma, tienen ante usted un trabajo científico consolidado en el tiempo y sólido en cuanto al contenido, fiel reflejo de, a pesar del difícil contexto, el buen hacer de la joven doctrina iuslaboralista española

    El Derecho del Trabajo y de la Seguridad Social en España en 2016. Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social

    Get PDF
    En su quinta edición, el Informe “El Derecho del Trabajo y de la Seguridad Social en España 2018” le ofrece una síntesis, que por concreta no es menos rigurosa, de los principales hitos por los que ha transitado el iuslaboralismo a lo largo del último año. En concreto, en las páginas que siguen, los expertos integrantes de la Sección Juvenil de la Asociación Española de Derecho del Trabajo y de la Seguridad Social (AEDTSS) analizan para usted, en primer lugar, las principales resoluciones europeas y nacionales en materia de igualad y no discriminación, acoso en sus más diversas manifestaciones, liberad religiosa y libertad de expresión. Asimismo, se abordan también las cuestiones relativas al empleo y la contratación, casi monopolizadas por el impacto de las plataformas y las consecuencias del caso de Diego. En materia de vicisitudes, sin perder importancia el despido colectivo, observará un cierto auge de los casos relativos a sucesión empresarial, movilidad funcional y empleo público. En el ámbito del derecho colectivo, además de analizarse el IV AENC, encontrará un estudio pormenorizado de las principales resoluciones en materia de libertad sindical, representación unitaria y ultraactividad. La sección relativa a conciliación y corresponsabilidad incluye este año como novedad un apartado relativo a violencia de género, al hilo de los avances normativos derivados del Real Decreto-ley 9/2018. Los epígrafes concernientes a la protección social y la prevención de riesgos laborales crecen de forma significativa en esta edición, lo que ha permitido abordar la evolución jurisprudencial para buena parte de las prestaciones y riesgos previstos en la Ley. Por último, las expertas del apartado de derecho procesal se han encargado de revisar a fondo los casos más significativos en el marco de las modalidades procesales especiales, con especial hincapié en el ámbito concursal. También han abordado la jurisprudencia constitucional más reciente sobre el de recurso de reposición. En suma, tienen ante usted un trabajo científico consolidado en el tiempo y sólido en cuanto al contenido, fiel reflejo de, a pesar del difícil contexto, el buen hacer de la joven doctrina iuslaboralista española. The fifth edition of the report, "Labour and Social Security Law in Spain in 2018" analyses the key issues in the changing scenario of Labour Law and Social Security during last year. Elaborated by the Young Scholars’ Section of the Spanish Association of Labour and Social Security Law focuses on the following thematic blocks: non-specific fundamental rights; employment contracts and employment; issues related to employment relationship; collective rights; equality and co-responsibility; occupational risks prevention; and procedural law. In conclusion, you may find here a concrete but detailed analysis of the the main legal and case law novelties of Spanish Social Law

    Role of age and comorbidities in mortality of patients with infective endocarditis

    Get PDF
    [Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
    corecore