Assessment of neighbor particles searching methods for discrete element method (DEM) based simulations

The performance of discrete element method (DEM) simulations is highly dependent on the requirements of the associated algorithms in terms of computer memory usage and CPU time. In particular, computer CPU time heavily depends on the identification of neighbor particles and the computation of particle-particle interactions. Over the years several neighbor particles searching methods have been developed. Accordingly, in this work the performance of two of well-known searching methods, linked cell and Verlet tables algorithms, are assessed in the context of the development of a new DEM-based tool. More specifically, the neighbor searching methods performance and related computational costs are parametrically analyzed and an assessment of their suitability for carrying the intended numerical simulations is provided. The referred numerical simulations are performed accounting for a canonical configuration used for the verification of the algorithms included in the new computational tool under development. The referred tool incorporating state of the art physical and numerical models will be used for modelling following a CFD-DEM approach mineral transport and grinding processes present in concentrator plants

Adaptive Navigation, Guidance and Control Techniques Applied to Ballistic Projectiles and Rockets

Accuracy and precision are the cornerstone for ballistic projectiles from the earliest days of this discipline. In the beginnings, impact point precision in artillery devices deteriorated when range were extended, particularly for non-propelled artillery rockets and shells. Later, inertial navigation and guidance systems are introduced and precision was unlinked from range increases. In the last 30 years, hybridization between inertial systems and GNSS devices has improved precision enormously. Unfortunately, during the last stages of flight, inertial and GNSS methods (hybridized or not) feature big errors on attitude and position determination. Low cost devices, which are precise on terminal guidance and do not feature accumulative error, such as quadrant photo-detector, seem to be appropriate to be included on the guidance systems. Hybrid algorithms, which combine GNSSs, IMUs and photodetectors, and a novel technic of attitude determination, which avoids the use of gyroscopes, are presented in this chapter. Hybridized measurements are implemented on modified proportional navigation law and a rotatory force control method. A realistic non-linear flight dynamics model has been developed to perform simulations to prove the accuracy of the presented algorithms

Factores Asociados a Reincidencia de Embarazo en Adolescentes Atendidas en el Hospital II-1 Moyobamba

El objetivo del presente trabajo de investigación fue evaluar los factores asociados a reincidencia de embarazo en adolescentes atendidas en el Hospital II-1 Moyobamba, durante el año 2015- 2019. Material y métodos: Se desarrolló un estudio observacional analítico de diseño casos y controles. La muestra a estudiar estuvo constituida por 210 adolescentes cuya atención prenatal se realizó en el Hospital II-1 Moyobamba en el periodo 2015 a 2019, se incluyeron a las participantes de acuerdo a los criterios de selección, las cuales se distribuyeron en 70 casos y 140 controles. Resultados: El factor sociodemográfico que demostró asociación para reincidencia de embarazos fue: ocupación (OR 2.02, IC=1,06-3,84), este resultado es estadísticamente significativo. Con respecto a los factores gineco obstétricos el factor que se asoció a reincidencia de embarazos fue: Número de parejas sexuales (OR=2,75, IC95%=1.38-5.49) constituye un factor de riesgo y es estadísticamente significativo. El embarazo planificado se postuló como factor protector (OR=0,31 IC 95%= 0,13-0,73 p=0.010). Este resultado fue estadísticamente significativo. Conclusión: Los factores ocupación y número de parejas sexuales, se asociaron a embarazo reincidente, mientras que embarazo planificado se postuló como factor protector.The objective of this research work was to evaluate the factors associated with recidivism of pregnancy in adolescents treated at Hospital II-1 Moyobamba, during the year 2015-2019. Material and methods: An analytical observational study of case-control design was developed. The sample to be studied consisted of 210 adolescents whose prenatal care was carried out at the Hospital II-1 Moyobamba in the period 2015 to 2019, the participants were included according to the selection criteria, which were distributed in 70 cases and 140 controls. Results: The sociodemographic factors that demonstrated association for recidivism of pregnancy were: occupation (OR 2.02) whose confidence interval 95% (CI=1.06-3.84), this result is statistically significant. Regarding the gynecological-obstetric factors, the factors that were associated with recurrence of pregnancy were: Number of sexual partners (OR=2.75, 95%CI=1.38-5.49) constitutes a risk factor and is statistically significant. The planned pregnancy was postulated as a protective factor (OR=0.31 95% CI= 0.13-0.73 p=0.010). This result was statistically significant. Conclusion: The factors occupation and number of sexual partners were associated with recurrent pregnancy, while planned pregnancy was postulated as a protective factorTesi

Cochlear Implantation in Patients with Neurofibromatosis Type 2 and Patients with Vestibular Schwannoma in the Only Hearing Ear

Cochlear implants are a new surgical option in the hearing rehabilitation of patients with neurofibromatosis type 2 (NF2) and patients with vestibular schwannoma (VS) in the only hearing ear. Auditory brainstem implant (ABI) has been the standard surgical treatment for these patients. We performed a literature review of patients with NF2 and patients with VS in the only hearing ear. Cochlear implantation (CI) provided some auditory benefit in all patients. Preservation of cochlear nerve integrity is crucial after VS resection. Results ranged from environmental sound awareness to excellent benefit with telephone use. Promontory stimulation is recommended although not crucial. MRI can be performed safely in cochlear implanted patients

Balances y perspectivas de los procesos de concentración empresarial en el desarrollo de la economía peruana y su impacto en el sector financiero

Durante los últimos años, las concentraciones empresariales han puesto de manifiesto el cambio de la visión tradicional de la empresa a la concepción de la empresa moderna. Este tránsito ha sido resultado de las exigencias actuales de los mercados que afectados, especialmente, por los fenómenos de la globalización, reclaman la implementación de nuevas estrategias empresariales. Los resultados económicos ponen de manifiesto que los procesos de concentración más utilizados han sido las fusiones, adquisiciones y –recientemente- la constitución de grupos de empresas. De esta manera se ha hecho posible que la economía peruana muestre importantes cambios en su desarrollo, proyectándose un óptimo crecimiento en los años futuros. Dicha situación tiene importante reflejo en el sector financiero donde la presencia de los grupos económicos se ha fortalecido considerablemente, pero al mismo tiempo ha planteado importantes desafíos en la regulación; sobre todo porque es función del Estado compatibilizar el interés privado con el interés social; que tenga a la justicia como valor rector, en equilibrio dinámico con la libertad, fundamentando en ambos la construcción de una sociedad con mayores niveles de equidad

Service-learning, educational innovation and geography: an experience in assessing territorial heritage in the Biosphere Reserve of the area known as the Ancares Leoneses (Cantabrian mountain range, Spain)

Producción CientíficaThe article weighs up the didactic proposal carried out by the authors in the Biosphere Reserve of the Ancares Leoneses (RBALE) with students enrolled in the Practical and Applied Geomorphology class of the fourth year of the Undergraduate Degree in Geography and Land-use Planning of the University of Valladolid. Its development has served, firstly, as a basis and a tool for geographical work in a mountain site of heritage value, a key objective of the matter. At the same time, it has allowed students to take part in a real service-learning experience, interacting with local parties and management entities of the RBALE. This experience was awarded the “Prize for Educational Innovation by the Social Council of the University of Valladolid -2013-”.CSO2012-39564-C07-0

El aprendizaje-servicio como propuesta didáctica para la enseñanza práctica de la geografía. Una experiencia de puesta en valor del patrimonio natural

Producción CientíficaSe analizan los resultados de la experiencia de aprendizaje-servicio desarrollada como soporte didáctico de la asignatura Geomorfología Práctica y Aplicada -cuarto curso del Grado de Geografía y Ordenación del Territorio de la Universidad de Valladolid-. La actividad ha consistido en la elaboración del “Inventario del patrimonio geomorfológico, valoración de la geodiversidad y propuesta de rutas turísticas por la Reserva de la Biosfera de los Ancares Leoneses”, contando para su realización con un convenio de colaboración entre la RBALE y la Universidad de Valladolid. Se explican los detalles organizativos de la experiencia, haciéndose especial énfasis en el balance participativo y en la implicación de los agentes locales

Future Needs for Tribo-Corrosion Research and Testing

Tribo-corrosion is an emerging interdisciplinary subject that spans from basic research on the behavior of surfaces in mechanical contact in chemically active surroundings to the test methods needed to quantify its effects, and from the selection of materials for bio-implants to the minimization of surface degradation and wastage in advanced energy conversion systems. Such a diverse field brings with it many challenges in understanding, testing, standardization, and application to engineering practice. This paper summarizes a panel discussion and participant survey held at the Third International Symposium on Tribo-Corrosion in Atlanta, Georgia, USA, in April 2012. It reflects a sense of agreement on many of the key scientific challenges in the field and the fact that tribo-corrosion is still in its infancy in terms of broad industry recognition, education, and the ability of those who conduct tribo-corrosion research to connect their laboratory results and theories to applications. Some sub-fields, notably the bio-tribo-corrosion of medical implants, have witnessed active international research efforts, but the engineering community in many other important areas of technology may not yet be aware of the field despite numerous tribo-corrosion problems that may exist within their purview

Análisis del Proceso Administrativo Disciplinario del Personal Asistencial del Hospital Santa Rosa de la ciudad de Puerto Maldonado - 2018

El presente estudio de investigación asume como propósito de efectuar el “Análisis del Proceso Administrativo Disciplinario del Personal Asistencial del HSR-PM- 2018”. El estudio de tipo no experimental cuenta con un diseño descriptivo, presenta una muestra poblacional de 54 colaboradores el mismo que es un muestreo no probabilístico. Para la recolección de datos, se usaron un cuestionario tipo Likert, para medir la percepción de la variable Proceso Administrativo Disciplinario y sus dimensiones; los que fueron validados con la técnica Alfa de Cronbach, obteniendo (0,762) de fiabilidad. Se considera un valor aceptable, de acuerdo a los criterio general, George y Mallery 2003, p. 231

Galería

The images of the designer and photographer Luis Carlos Celis Calderón that appear at the end of this edition were taken in various spaces of the University of Bogotá Jorge Tadeo Lozano. They are bodies that walk, that rise and fall, that rest, that play, that argue. They are students, teachers and workers who measure and measure this giant little world of the university. Celis's photos speak of the body that measures personal relationships, that gives meaning to the vision of the world, that implies a collective imagination. That image of the body that is shared, that culture of the body that intensifies: that university life that is dreamed of. With these images we open a new section in the magazine. Here we explore the relationship between the subject matter –the body, on this occasion– with art, design, architecture and the city. With these photos, the inquiry about the private body and the public body is combined: the interior on the exterior.Las imágenes del diseñador y fotógrafo Luis Carlos Celis Calderón que aparecen al cierre de esta edición fueron tomadas en varios espacios de la Universidad de Bogotá Jorge Tadeo Lozano. Son cuerpos que pasean, que suben y bajan, que descansan, que juegan, que discuten. Son estudiantes, profesores y trabajadores que miden y dan la medida a este pequeño mundo gigante de la universidad. Las fotos de Celis hablan del cuerpo que mide las relaciones personales, que da significado a la visión del mundo, que implica un imaginario colectivo. Esa imagen del cuerpo que se comparte, esa cultura del cuerpo que se intensifica: esa vida universitaria que se sueña. Con estas imágenes abrimos una nueva sección en la revista. Aquí, damos cabida a explorar la relación entre el tema tratado –el cuerpo, en esta ocasión– con el arte, el diseño, la arquitectura y la ciudad. Con estas fotos, se conjuga la indagación sobre el cuerpo privado y el cuerpo público: lo interior en el exterior