Torque control strategy for an axial flux switched reluctance machine

This paper reflects the work done to design a torque control strategy for an axial flux switched reluctance machine. The general electrical model is first presented but as the switched reluctance machine behaves nonlinearly1 a (three-dimensional) finite element method characterization is performed, so the nonlinearity may be considered. Once the machine is characterized in FEM a Simulink model is developed where a torque control strategy is proposed. Then, both the machine and the control are experimentally tested. The control setting, and the obtained real performance results are also presented in this document. Finally, the most outstanding conclusions about the control strategy are captured. Main difficulties encountered during the implementation of the control strategy are also collected

Teachers as researchers: Reflecting on the challenges of research–practice partnerships between school and university in Chile

Teachers have tended to be underestimated as experts of their own practice and relegated to a technical role. In this context, action research appears as a form to legitimate teachers as active agents and producers of educational knowledge. This article aims to examine how a collaborative research–practice partnership between schools and universities in Chile fosters teachers’ role as researchers. It adopts a qualitative methodology based on thematic analysis of data collected from questionnaires and focus groups. In particular, it reports perceptions of inservice teacher researchers who conducted research projects between 2016 and 2017 as a part of a researcher–practitioner partnership strategy implemented by a university in Chile. The findings suggest that the partnerships were highly valued among teachers because the partnerships allowed them to develop pedagogical reflection towards the improvement of their practices and required particular awareness and recognition of roles and the relationships between practical and theoretical knowledge. Finally, possibilities for strengthening teachers’ role as researchers and collaborative research are presented at the end of the article

Aplicación del cálculo paralelo al análisis de energía sísmica en la coda de terremotos regionales

Coda waves constitute a powerful tool for the estimation of the seismic wave attenuation in the Earth s lithosphere. Total attenuation includes two effects: intrinsic absorption and scatttering, that can be separated if we perform a multiple scattering modelling of the coda envelope. In this paper we will compare, in terms of the computational point of view, two techniques (a Montecarlo simulation and an analytical procedure) for obtaining the theoretical space and time distribution of the seismic energy in the coda, under the hypothesis of multiple isotropic scattering and uniform distribution of scatterers. We will study the characteristic of the algorithms and will use parallelization techniques in order to reduce the time required for obtaining the results

Estudio de atenuación sísimica en la costa este de la Península Ibérica

El gradiente de decaimiento de la amplitud a lo largo de la coda se caracteriza por el parámetro coda-Q-1 (Qc-1) que es constante independientemente de la localización de la fuente sísmica y de la estación de registro en una región determinada, y que representa una estimación de la atenuación sísmica introducida por el medio. Otros parámetros que caracterizan la atenuación sísmica son: la absorción intrínseca ( Qi-1 ), la atenuación por dispersión ( Q8-1) y la atenuación total Qt –1= Qi-1 + Q8-1. En el presente estudio se han analizado 64 terremotos registrados por 11 estaciones de período corto distribuidas a lo largo de la costa este de la Península Ibérica, de cara a la estimación de la atenuación sísmica y su dependencia frecuencial. En este trabajo se describe el método numérico utilizado y se presentan los parámetros de atenuación estimados para la costa mediterránea española

Characterization of the biosynthesis of beta(1-2) cyclic glucan in R. Fredii. Beta(1-2) glucan has no apparent role in nodule invasion of Mc Call and Peking soybean cultivars.

Three wild type strains of Rhizobium fredii, USDA 191, USDA 257 and HH 303, do not synthesize in vivo or in vitro beta(1-3), beta(1-6) cyclic glucans, all strains form in vitro and in vivo cyclic beta(1-2) glucans. Approximately 80% of the recovered R. fredii cellular cyclic beta(1-2) glucans were anionic and the substituent was identified as phosphoglycerol. Inner membranes prepared from these R. fredii strains have a beta(1-2) glucan-intermediate-protein with apparent molecular mass undistinguishable from Agrobacterium tumefaciens beta(1-2) glucan intermediate protein. Studies of the degree of polymerization of the oligosaccharides recovered from the protein-intermediate after short pulse incubations with UDP-14C-glucose suggested that the rate limiting step in the biosynthesis of cyclic glucan is cyclization. Kinetic studies revealed that the K(m) for UDP-glucose was 0.33 mM. No difference was detected between the K(m) for initiation/elongation and cyclization reactions. Nodulation studies of a ndvB R. fredii mutant with Mc Call and Peking soybean cultivars, revealed that beta(1-2) glucans do not seem to be required for normal nodule invasion of these soybean cultivars.Fil:Ugalde, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Trans-splenic puncture during percutaneous nephrolithotomy: Outcome spectrum of the same complication

AbstractPercutaneous nephrolithotomy is an endourologic technique commonly used in the management of nephrolithiasis. However, this procedure is not complication-free. Splenic injury is exceptionally rare with a reported rate of 1% from the total case load. We present herein two cases of splenic puncture during percutaneous nephrolithotomy that illustrate two different outcomes. In the first case, the patient remained asymptomatic and was discharged on her third post-operative day after removing the nephrostomy, without any sign of hemodynamic compromise. In the second case, the patient presented with hemodynamic instability and an abdominal computed tomography scan was done that showed free fluid in the peritoneal cavity. Emergency laparotomy was performed and revealed a deep peripheral laceration (20mm×5mm in length) that required splenectomy. After a thorough review of the existing literature, we could find only 11 other instances of injury to the spleen in which treatment outcomes were reported. Patient hemodynamic status was the main factor in deciding on the type of treatment

Aplicación del cálculo paralelo al análisis de energía sísmica en la coda de terremotos regionales

Las ondas de coda constituyen un instrumento muy útil de cara a la estimación de la atenuación de las ondas sísmicas durante su propagación a través de la litosfera terrestre. La atenuación total consta de dos efectos principales: la absorción intrínseca y la dispersión, que pueden ser separados si se efectúa una modelización de la envolvente de la coda sobre la base de la teoría de esparcimiento múltiple. En este trabajo compararemos, desde el punto de vista computacional, dos técnicas (una simulación por el método de Montecarlo y un procedimiento analítico) para obtener la distribución espacio-temporal teórica de la energía sísmica en la coda, bajo las hipótesis de dispersión isótropa múltiple y distribución uniforme de dispersores. Para ello estudiaremos las características de los algoritmos e introduciremos el cálculo paralelo, en un intento de reducir el tiempo de computación necesario para obtener los resultados.Coda waves constitute a powerful tool for the estimation of the seismic wave attenuation in the Earth's lithosphere. Total attenuation includes two effects: intrinsic absorption and scatttering, that can be separated if we perform a multiple scattering modelling of the coda envelope. In this paper we will compare, in terms of the computational point of view, two techniques (a Montecarlo simulation and an analytical procedure) for obtaining the theoretical space and time distribution of the seismic energy in the coda, under the hypothesis of multiple isotropic scattering and uniform distribution of scatterers. We will study the characteristic of the algorithms and will use parallelization techniques in order to reduce the time required for obtaining the results.Peer Reviewe

Caracterización de espacios de Banach mediante desigualdades y el mapeo de dualidad

Using a result of C. E. Chidume, we present a shorter and improved proof of aresult of Xu and Roach on characterization of uniformly convex and uniformly smoothBanach spaces by the duality map and inequalities involving strictly increasing andstrictly decreasing functions.Keywords: Banach spaces, duality maps, uniformly convex spaces, uniformly smoothspaces, modulus of convexity, modulus of smoothness.Usando un resultado de C. E. Chidume, presentamos una prueba mejorada y m´ascorta de un resultado de Xu y Roach sobre caracterizaci´on de espacios de Banachuniformemente convexos y uniformemente suaves mediante el mapeo de dualidad ydesigualdades que involucran funciones estr´?ctamente crecientes y estr´?ctamente decrecientes.Palabras clave: espacios de Banach, mapeos de dualidad, espacios uniformemente convexos,espacios uniformemente suaves, m´odulo de convexidad, m´odulo de suavidad