Evaluación de las propiedades dinámicas de un pórtico plano (MDOF) en una mesa vibratoria

At present, the study of structural dynamics is mainly theoretical with access to certain simulations through software, however, this project attempts that the student may understand and physically observe the dynamic responses of experimental models. These models correspond to 2D - frames with multiple degrees of freedom that are subjected to acceleration in the base; this acceleration is generated by a Shake Table II, and the results obtained will be compared with theoretical results. These theoretical results were obtained based on modal decomposition and Newmark's method for calculating the dynamic response, considering the linear variation in the acceleration of each floor. The application developed, ATH Dynamic Responses, provided the theoretical responses through a graphical interface friendly for the user. The experimental models are constituted by two materials: stainless steel for frame legs and acrylic sheets for floors; these were tested on a Shake Table II”. The data was acquired using accelerometers that were placed in each floor and in the shake table, and they were corrected both by baseline and with the low pass filter. The results obtained show that the instrumentation with the Shake Table II and the data acquisition with accelerometers provide results similar to the theoretical ones regarding dynamic responses and modal properties.Hoy en día, el estudio de la dinámica estructural es fundamentalmente teórico con acceso a ciertas simulaciones vía \emph{software}, sin embargo, este proyecto intenta que el estudiante pueda entender y observar de manera física las respuestas dinámicas de modelos experimentales. Estos modelos corresponden a pórticos planos de múltiples grados de libertad, que están sometidos a aceleración en la base, la cual es generada por una mesa vibratoria. Los resultados obtenidos se compararán con teóricos. Estos fueron obtenidos basándose en la descomposición modal y en el método de Newmark para el cálculo de la respuesta dinámica, considerando variación lineal en la aceleración de cada piso. La aplicación generada, ATH Dynamic Responses, proporcionó las respuestas teóricas, mediante una interfaz gráfica amigable para el usuario. Los modelos experimentales están constituidos por dos materiales: acero inoxidable (parantes) y láminas de acrílico (pisos), y fueron ensayados sobre una mesa vibratoria. La adquisición de datos se realizó mediante acelerómetros que se colocaron en cada piso y sobre la mesa vibratoria, fueron corregidos, tanto por línea base como con el filtro pasa bajo. Los resultados obtenidos muestran que la instrumentación con una mesa vibratoria y adquisición de datos con acelerómetros proporcionan valores muy similares a los teóricos en cuanto a respuestas dinámicas y propiedades modales

Chronic diarrhoea in children.

Chronic diarrhoea in children shows an age related spectrum. In infants and young children a major role is related to persistent intestinal infections, intolerance to specific nutrients such as cow's milk protein, and toddler's diarrhoea. In older children and adolescents, inflammatory bowel diseases are strongly increasing and nonspecific diarrhoea is also frequent. Coeliac disease is a major cause of diarrhoea throughout childhood. In neonates, congenital diarrhoea is a rare but severe syndrome that includes several highly complex diseases. In children, diagnosis should be based on noninvasive techniques. Endoscopy should be decided based on clinical criteria, but also driven by noninvasive tests to assess the digestive absorptive functions and intestinal inflammation. A stepwise approach may reduce the need of endoscopy, also in the light of its relatively limited diagnostic yield compared to adult patients. Treatment of chronic diarrhoea in children is also substantially different from what is generally done in adults and includes a major role for nutritional interventions. Therefore chronic diarrhoea in children is a complex age-specific disorder that requires an age-specific management that is in many aspects distinct from that in adults

Determinación de la matriz de riesgos psicosociales y propuesta de un plan de remediación para la planta industrial. Caso: Maresa

Maresa fue constituida el 18 de agosto de 1976, durante más de tres décadas, ha ensamblado camiones, pick-ups y autos de pasajeros de marcas reconocidas a nivel mundial, como son Mack, Fiat, Mitsubishi, Ford, Toyota y Mazda, en una extensa variedad de modelos. Actualmente, es una empresa dedicada al ensamblaje de vehículos Mazda, marca japonesa con la cual mantiene una sólida relación cultivada a lo largo de 27 años de trabajo conjunto. Maresa tiene varios procesos de acuerdo a su actividad económica, su capital humano es grande y muy importante para su desarrollo, es por esto que se ve en la necesidad de medir factores de riesgo psicosocial dentro de la planta industrial desde la realidad nacional y en base a las normas vigentes que plantean los organismos de regulación. El capítulo 1 muestra el análisis del sector industrial dedicado al ensamblaje de autos y su situación actual en el país, se describe la trayectoria de la industria automotriz, también las empresas con mayor productividad, su ubicación y las marcas que ensambla. La CINAE en brinda información sobre exportaciones, importaciones y unidades producidas en el sector automotriz del Ecuador. Se ubica al sector automotriz en la Clasificación Industrial Internacional Uniforme de todas las Actividades Económicas (CIIU). Se incluye el análisis de la situación actual de la empresa, su historia y evolución, la producción de autos y las exportaciones. En el capítulo 2 se realiza el análisis interno, donde se determinan los factores de riesgo psicosocial, se identifican los puestos de trabajo y se realiza la clasificación de los cargos críticos. Al determinar los factores de riesgo psicosocial se analizan los efectos que estos traen, los riesgos que existen en el trabajo, también la normativa internacional y el marco legal vigente en el Ecuador. Para la identificación de los puestos de trabajo se parte de los organigramas de cada una de las áreas de la empresa. Partiendo de la clasificación de cargos se calculó la muestra para el desarrollo de los cuestionarios. El capítulo 3 contiene la planificación y elaboración de la matriz de riesgos, la medición de los riesgos psicosociales y el análisis de la información. El presente trabajo de titulación emplea la metodología F-Psico elaborada por Instituto Nacional de Seguridad e Higiene en el trabajo junto con el Ministerio de Empleo y Seguridad Social y Gobierno de España, con su herramienta informática que genera los datos para la construcción de la matriz de riesgos psicosociales. En el capítulo 4 se encuentra el plan de remediación que servirá para mejorar las situaciones de riesgo psicosocial en la empresa Maresa Ensambladora. Finalmente el capítulo 5 plantea las conclusiones y recomendaciones fundamentadas en el análisis de los resultados, en la matriz de riesgos y en el plan de remediación

Impact of the Primary Break-Up Strategy on the Morphology of GDI Sprays in 3D-CFD Simulations of Multi-Hole Injectors

The scientific literature focusing on the numerical simulation of fuel sprays is rich in atomization and secondary break-up models. However, it is well known that the predictive capability of even the most diused models is aected by the combination of injection parameters and operating conditions, especially backpressure. In this paper, an alternative atomization strategy is proposed for the 3D-Computational Fluid Dynamics (CFD) simulation of Gasoline Direct Injection (GDI) sprays, aiming at extending simulation predictive capabilities over a wider range of operating conditions. In particular, attention is focused on the eects of back pressure, which has a remarkable impact on both the morphology and the sizing of GDI sprays. 3D-CFD Lagrangian simulations of two dierent multi-hole injectors are presented. The first injector is a 5-hole GDI prototype unit operated at ambient conditions. The second one is the well-known Spray G, characterized by a higher back pressure (up to 0.6 MPa). Numerical results are compared against experiments in terms of liquid penetration and Phase Doppler Anemometry (PDA) data of droplet sizing/velocity and imaging. CFD results are demonstrated to be highly sensitive to spray vessel pressure, mainly because of the atomization strategy. The proposed alternative approach proves to strongly reduce such dependency. Moreover, in order to further validate the alternative primary break-up strategy adopted for the initialization of the droplets, an internal nozzle flow simulation is carried out on the Spray G injector, able to provide information on the characteristic diameter of the liquid column exiting from the nozzle

The Design Posture: A Collaborative Learning-By-Doing Approach

In September 2021, Codesign Toscana1 organised a pop-up school animated by a concept implicitly present in many design-related debates and around which our practices as an interdisciplinary collective have developed over the last five years: the “Design Posture” (hereafter DP). By relying on a collaborative design framework, we experimented with a cooperative learning approach using the urban context as a non-formal education platform and, following the direct experience of the pop-up school, named “Response/Ability” we discuss the possibility of new horizons in the urban context to organize educational platforms that rely on reclaimed city spaces and that generate insights for young generations

Acute disseminated encephalomyelitis presenting as fever of unknown origin: case report

BACKGROUND: Fever of unknown origin (FUO) can be defined as a body temperature higher than 38.3°C on several occasions over more than 3 weeks, the diagnosis of which remains uncertain after 1 week of evaluation. Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system with a wide range of clinical manifestations. The highest incidence of ADEM is observed during childhood and it usually occurs following a viral or bacterial infection or, more rarely, following a vaccination, or without a preceding cause. CASE PRESENTATION: Here, we describe an atypical case of ADEM that initially manifested as several weeks of FUO in a fifteen years old boy. CONCLUSIONS: This case report suggests a new possible syndromic association between ADEM and FUO, which should be considered in the clinical examination of patients with FUO, especially in the presence of also modest neurologic or neuropsychiatric symptoms

Acute Disseminated Encephalomyelitis Presenting as Fever of Unknown Origin: Case Report

Background: Fever of unknown origin (FUO) can be defined as a body temperature higher than 38.3°C on several occasions over more than 3 weeks, the diagnosis of which remains uncertain after 1 week of evaluation. Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system (CNS) with a wide range of clinical manifestations. The highest incidence of ADEM is observed during childhood and it usually occurs following a viral or bacterial infection or, more rarely, following a vaccination, or without a preceding cause. Case presentation: Here, we describe an atypical case of ADEM that initially manifested as several weeks of FUO in a 15 years old boy. Conclusions: This case report suggests a new possible syndromic association between ADEM and FUO, which should be considered in the clinical examination of patients with FUO, especially in the presence of also modest neurologic or neuropsychiatric symptoms.&nbsp

Search for genetic variants in the p66Shc longevity gene by PCR-single strand conformational polymorphism in patients with early-onset cardiovascular disease.

Background: Among the possible candidate genes for atherosclerosis experimental data point towards the longevity gene p66(Shc). The p66(Shc) gene determines an increase of intracellular reactive oxygen species (ROS), affecting the rate of oxidative damage to nucleic acids. Knock-out p66(Shc-/-) mice show reduction of systemic oxidative stress, as well as of plasma LDL oxidation, and reduced atherogenic lesions. Thus, p66(Shc) may play a pivotal role in controlling oxidative stress and vascular dysfunction in vivo. Methods: We searched for sequence variations in the p66(Shc) specific region of the Shc gene and its upstream promoter by PCR-SSCP in a selected group of early onset coronary artery disease ( CAD) subjects (n. 78, mean age 48.5 +/- 6 years) and in 93 long-living control subjects ( mean age 89 +/- 6 years). Results: The analysis revealed two variant bands. Sequencing of these variants showed two SNPs: -354T > C in the regulatory region of p66(Shc) locus and 92C > T in the p66 specific region (CH2). Both these variants have never been described before. The first substitution partially modifies the binding consensus sequence of the SpI transcription factor, and was detected only in two heterozygous carriers (1 CAD subjects and 1 control subject). The 92C > T substitution in the CH2 region consists in an amino acid substitution at codon 31 (proline to leucine, P31L), and was detected in heterozygous status only in one CAD subject. No subjects homozygous for the two newly described SNPs were found. Conclusion: Only two sequence variations in the p66(Shc) gene were observed in a total of 171 subjects, and only in heterozygotes. Our observations, in accordance to other studies, suggest that important variations in the p66(Shc) gene may be extremely rare and probably this gene is not involved in the genetic susceptibility to CAD