Modelling of a wind turbine with permanent magnet synchronous generator

This investigation presents the implementation and simulation of a Simulink-based controlled permanent magnet synchronous generator (PMSG) wind turbine in the dq0 reference frame. The model consists of a current control subsystem, a PMSG model, a mechanical subsystem, a pitch angle controller and a wind turbine model. The current control subsystem makes use of PI controllers governing the wind turbine speed, the direct and quadrature stator currents and the pitch angle of the turbine blades. The pitch angle controller measures the speed and the active power from the generator limiting both in case of high-speed wind conditions. In order to verify the functioning and the effectiveness of the proposed controllers, simulations- for different operation conditions- are presented and discussed

Transcription of Leishmania major U2 small nuclear RNA gene is directed by extragenic sequences located within a tRNA-like and a tRNA-Ala gene

Sequence comparisons of U2 snRNA genes and flanking regions from T. cruzi (CL Brener Non-Esmeraldo-like). Sequences from the genes located on chromosomes 23, 37 and 6 are shown. The U2 snRNA gene from chromosome 23 is presented in blue font. The position of boxes A and B is indicated. Sequence numbers are relative to the TSS (+1) from the U2 snRNA. (PDF 1404 kb

Incidence of complications in breast reconstruction with autologous tissue in a third level hospital

Background: The objective of this study is to analyze the incidence of complications after breast reconstruction with pedicled or free flaps at the hospital general de Mexico "Dr. Eduardo Liceaga”. Methods: A retrospective, single-center study, including 44 female patients, who underwent immediate or delayed breast reconstruction after breast cancer, between 2019 and 2020, and had at least a 2-year follow up, evaluating the association between patient risk factors (age, history of radiotherapy, presence of overweight or obesity and immediate or delayed reconstruction) with the presence of complications such as seroma, hematoma, wound infection or wound dehiscence. We analyzed data with SPSS software, v23.0. Results: There was no statistically significant difference for the presence of complications associated with risk factors studied. Conclusions: We need more prospective, multicenter studies, including larger sample and strict follow up of patients

Determinación de la calidad visual del paisaje. Estudio de caso: Sierras de la Pedrera.

El paisaje se define como “la impresión visual de una porción del espacio terrestre habitada por el hombre, cuyas características permiten considerarlo como una entidad homogénea diferente a otras” (Núñez 2.000), que representa un aspecto importante para la ordenación del territorio. A partir de la metodología de Zambrano, M. del C. y González, V. R. (modificada) es posible valorar el paisaje concluyendo en tres unidades cartográficas que diferencian la calidad visual de paisaje de modo relativo, para ello se realizó un relevamiento de los factores ambientales vinculados al paisaje, para realizar un análisis pertinente de cada componente que se seleccionaron para la valoración del paisaje

Height-based equations as screening tools for high blood pressure in pediatric practice, the GENOBOX study

Due to the absence of easily applicable cut-off points to determine high blood pressure or hypertension in children, as in the adult population, blood pressure is rarely measured in the pediatrician''s clinical routine. This has led to an underdiagnosis of high blood pressure or hypertension in children. For this reason, the present study evaluate the utility of five equations for the screening of high blood pressure in children: blood pressure to height ratio, modified blood pressure to height ratio, new modified blood pressure to height ratio, new simple formula and height-based equations. The authors evaluated 1599 children between 5 and 18 years. The performance of the five equations was analyzed using the receiver-operating characteristics curves for identifying blood pressure above P90th according to the American Academy of Pediatrics Clinical Practice Guideline 2017. All equations showed an area under the curve above 0.882. The new modified blood pressure to height ratio revealed a high sensitivity whereas the height-based equations showed the best performance, with a positive predictive value above 88.2%. Finally, all equations showed higher positive predictive values in children with overweight or obesity. The height-based equation obtained the highest PPV values above 71.1% in children with normal weight and above 90.2% in children with overweight or obesity. In conclusions, the authors recommend the use of the height-based equations equation because it showed the best positive predictive values to identify children with elevated blood pressure, independently of their sex, pubertal and weight status. © 2022 The Authors. The Journal of Clinical Hypertension published by Wiley Periodicals LLC

Hybrid materials based on polyethylene and MCM-41 microparticles functionalized with silanes: catalytic aspects of in situ polymerization, crystalline features and mechanical properties

New nanocomposites based on polyethylene have been prepared by in situ polymerization of ethylene in presence of mesoporous MCM-41. The polymerization reactions were performed using a zirconocene catalyst either under homogenous conditions or supported onto mesoporous MCM-41 particles, which are synthesized and decorated post-synthesis with two silanes before polymerization in order to promote an enhanced interfacial adhesion. The existence of polyethylene chains able to crystallize within the mesoporous channels in the resulting nanocomposites is figured out from the small endothermic process, located at around 80 C, on heating calorimetric experiments, in addition to the main melting endotherm. These results indicate that polyethylene macrochains can grow up during polymerization either outside or inside the MCM-41 channels, these keeping their regular hexagonal arrangements. Mechanical response is observed to be dependent on the content in mesoporous MCM-41 and on the crystalline features of polyethylene. Accordingly, stiffness increases and deformability decreases in the nanocomposites as much as MCM-41 content is enlarged and polyethylene amount within channels is raised. Ultimate mechanical performance improves with MCM-41 incorporation without varying the final processing temperature

Marco legal de los riesgos profesionales y la salud ocupacional en colombia, siglo xx

Objetivo Analizar la normativa emitida en Colombia desde la perspectiva del derecho del trabajo, la seguridad social y la salud pública en el siglo XX, para identificar las concepciones en torno a la salud ocupacional y los riesgos profesionales, estableciendo las convergencias y diferencias que existen entre cada una de estas líneas y si responden o no a una visión complementaria.Método Investigación documental, mediante un análisis categorial temático de las reglamentaciones y estatutos promulgados en el siglo XX en Colombia, considerando el elemento o materia principal que se encarguen de regular relacionado con los riesgos profesionales o la salud ocupacional.Resultados Se construyó una periodización del desarrollo normativo en salud laboral en el país en el siglo XX, permitiendo evidenciar el predominio histórico de la visión del derecho social, que se concentra en la protección de los riesgos profesionales de los trabajadores dependientes, como una tendencia que se extiende hasta el Sistema General de Riesgos Laborales.Conclusiones Las etapas propuestas como eje ordenador de la normativa en riesgos profesionales y salud ocupacional posibilitan reconocer elementos trascendentales del contexto social, legal e institucional en el que emergieron tales reglamentaciones preocupadas por la salud de los trabajadores, advirtiéndose una tensión histórica entre las preceptivas dirigidas a la reparación y compensación de las contingencias relacionadas con el trabajo y aquellas directrices con una orientación preventiva

Mutations in the heat-shock protein A9 (HSPA9) gene cause the EVEN-PLUS syndrome of congenital malformations and skeletal dysplasia.

We and others have reported mutations in LONP1, a gene coding for a mitochondrial chaperone and protease, as the cause of the human CODAS (cerebral, ocular, dental, auricular and skeletal) syndrome (MIM 600373). Here, we delineate a similar but distinct condition that shares the epiphyseal, vertebral and ocular changes of CODAS but also included severe microtia, nasal hypoplasia, and other malformations, and for which we propose the name of EVEN-PLUS syndrome for epiphyseal, vertebral, ear, nose, plus associated findings. In three individuals from two families, no mutation in LONP1 was found; instead, we found biallelic mutations in HSPA9, the gene that codes for mHSP70/mortalin, another highly conserved mitochondrial chaperone protein essential in mitochondrial protein import, folding, and degradation. The functional relationship between LONP1 and HSPA9 in mitochondrial protein chaperoning and the overlapping phenotypes of CODAS and EVEN-PLUS delineate a family of "mitochondrial chaperonopathies" and point to an unexplored role of mitochondrial chaperones in human embryonic morphogenesis

Improved syntheses of aromatase inhibitors and neuroactive steroids efficient oxidations and reductions at key positions for bioactivity

An Henbest reduction, followed by the preparation of a silyl enol ether and oxidation in situ with m-CPBA has led to the neurosteroids 3[alpha]-hydroxy- and 3[alpha],21-dihydroxy-5[alpha]-pregnanolones. Using testosterone as starting material, a new short synthesis of an aromatase inhibitor, 4-OHA, has been achieved through hydroboration/oxidation followed by a Swern type oxidation and epimerization. Another aromatase inhibitor, androst-4-ene-3,6-17-trione, has been efficiently prepared using PCC on montmorillonite K10, under ultrasonic irradiation.http://www.sciencedirect.com/science/article/B6THR-3WC46V7-8/1/5f915790e78df65f4c988ab78bf4f17