Estimación paramétrica del modelo de un mini-helicóptero robot usando un algoritmo genético y Matlab-Simulink

Basándose en el modelo matemático para un mini-helicóptero robot implementado en Matlab-Simulink y métodos heurísticos, específicamente un algoritmo genético (AG), se logro hacer la estimación de 16 parámetros en forma simultánea a nivel de simulación. Los resultados son altamente satisfactorios, teniendo en cuenta que fueron estimados con 12 salidas

Mercury removal in wastewater by iron oxide nanoparticles

Mercury is one of the persistent pollutants in wastewater; it is becoming a severe environmental and public health problem, this is why nowadays its removal is an obligation. Iron oxide nanoparticles are receiving much attention due to their properties, such as: great biocompatibility, ease of separation, high relation of surface-area to volume, surface modifiability, reusability, excellent magnetic properties and relative low cost. In this experiment, Fe3O4 and γ-Fe2O3 nanoparticles were synthesized using iron salts and NaOH as precipitation agents, and Aloe Vera as stabilizing agent; then these nanoparticles were characterized by three different measurements: first, using a Zetasizer Nano ZS for their size estimation, secondly UV-visible spectroscopy which showed the existence of resonance of plasmon at λmax∼360 nm, and lastly by Scanning Electron Microscopy (SEM) to determine nanoparticles form. The results of this characterization showed that the obtained Iron oxides nanoparticles have a narrow size distribution (∼100nm). Mercury removal of 70% approximately was confirmed by atomic absorption spectroscopy measurements

Procesos más relevantes del control interno de una empresa hotelera

El objetivo de este artículo es identificar los procesos más relevantes del control interno en una entidad hotelera. Para ello se utiliza como instrumento la gestión por proceso, apoyado en herramientas estadísticas pertinentes como el análisis de motricidad, centralidady conglomerados. Como principal resultado se presenta la descripción de los procesos más relevantes del control interno definidos en la Resolución 60 del año 2011 de la Contraloría General de la República de Cuba, mediante la confección de la ficha de procesos y la realización del despliegue y el plan de actividades de los mismos, permitiendogestionar este sistema en la entidad hotelera objeto de estudio

Continuous and Localized Mn Implantation of ZnO

We present results derived from continuous and localized 35 keV (55)Mn(+) ion implantations into ZnO. Localized implantations were carried out by using self-ordered alumina membranes as masks leading to ordered arrays of implanted volumes on the substrate surfaces. Defects and vacancies in the small implantation volumes of ZnO were generated due to the implantation processes besides the creation of new phases. Rapid thermal annealing was applied in the case of continuous implantation. The samples were characterized by HRSEM, GIXRD, Raman spectroscopy and RBS/C. Magnetic characterization of the samples pointed out appreciable differences among the samples obtained by the different implantation methods. This fact was mainly attributed to the different volume/surface ratios present in the implanted zones as well as to the increase of Mn atom concentrations along the grain frontiers in the nanostructured surfaces. The samples also showed a ferromagnetic transition phase at temperature value higher than room temperature

Pulmonary thromboembolism and alveolar hemorrhage as initial manifestations of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs. SLE can affect the lung, the pulmonary vasculature, and the pleura. A 38-year-old female with limb pain and ecchymosis who later developed pulmonary thromboembolism and alveolar hemorrhage is presented here. Clinical, imaging, laboratory, and histopathological evidence is presented. The patient met the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) criteria for SLE. Furthermore, the patient had a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score of 35; thus, indicating severe disease. This case is an example of concomitant venous and arterial lung complications in an SLE patient

Caracterización y evaluaciçón de la capacidad de uso de los suelos de la comarca de "El Aljarafe" (Sevilla)

8 páginas, 5 tablas y 7 referencias. Comunicación presentada en las Actas del VII Congreso Nacional de Química (Química Agrícola y Alimentaria/2). Sevilla (España). 12 al 17 de Octubre de 1987. Vol. 1: "El suelo: fertilidad y fertilizantes". "La planta: aspectos bioquímicos y fisiológicos". "Protección vegetal"The soils of "El Aljarafe" region (Seville) are studied. As a result, different soils are found and classified into 19 taxonomic units of "Soil Taxonomy" (1975) System. Also. their land capability to relative, use, their erosion hazard and their ability for irrigation purposes, are evaluted. A soil map finally, to scale 1/50.000, with the results of the evaluation, is added.Peer reviewe

Magnetic order of Cr thin films in Nb/Cr/Fe-nanoisland hybrid: a comparative study between magnetic and superconducting properties

Shifted hysteresis loops characteristic of the exchange bias effect between a ferromagnet and an antiferromagnet are demonstrated in structures formed by a 2.5 nm Cr layer deposited on top of an array of Fe nanoislands (Cr/Fe-nanoislands). This effect evidences the persistence of antiferromagnetic (AF) order for Cr layers much thinner than the thickness reported in the literature. The field shift measured is found to increase for the smallest island sizes, which can be related with the enhancement of the Fe-nanoisland surface to volume ratio. The comparative study between superconducting proximity effects in Nb/Cr/Fe-nanoislands and Nb/normal metal/Fe-nanoisland hybrids (where the normal metals used are Al and Pt) confirms the presence of AF order in the 2.5 nm Cr spacer layer. A much shorter penetration depth of the Cooper pairs into the AF Cr layers than in the normal metal Pt and Al spacer layers is deduced