1,290 research outputs found

    A conceptual model of check dam hydraulics for gully control: efficiency, optimal spacing and relation with step-pools

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    There is little information in scientific literature regarding the modifications induced by check dam systems in flow regimes within restored gully reaches, despite it being a crucial issue for the design of gully restoration measures. Here, we develop a conceptual model to classify flow regimes in straight rectangular channels for initial and dam-filling conditions as well as a method of estimating efficiency in order to provide design guidelines. The model integrates several previous mathematical approaches for assessing the main processes involved (hydraulic jump, impact flow, gradually varied flows). Ten main classifications of flow regimes were identified, producing similar results when compared with the IBER model. An interval for optimal energy dissipation (ODI) was observed when the steepness factor <i>c</i> was plotted against the design number (DN, ratio between the height and the product of slope and critical depth). The ODI was characterized by maximum energy dissipation and total influence conditions. Our findings support the hypothesis of a maximum flow resistance principle valid for a range of spacing rather than for a unique configuration. A value of <i>c</i> = 1 and DN ~ 100 was found to economically meet the ODI conditions throughout the different sedimentation stages of the structure. When our model was applied using the same parameters to the range typical of step-pool systems, the predicted results fell within a similar region to that observed in field experiments. The conceptual model helps to explain the spacing frequency distribution as well as the often-cited trend to lower <i>c</i> for increasing slopes in step-pool systems. This reinforces the hypothesis of a close link between stable configurations of step-pool units and man-made interventions through check dams

    Radical distal ureterectomy secondary to an urotelial cancer and ureteral reconstruction robot-assisted. Case report

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    Indexación: Web of Science; ScieloObjective: To report a case of distal ureterectomy with robotic-assisted laparoscopic reimplantation using a Boari flap technique. Material and Methods: We report a 55 year old man with a diagnosis of distal ureteral urothelial carcinoma without multifocality. Results: A radical distal ureterectomy and robotic-assisted laparoscopic vesicoureteral reimplantation using a Boari flap technique was performed with the da Vinci S-HD surgical system. The operative time was 210 minutes, the estimated blood loss was 200 mL. The hospital stay was 48 hours, without perioperative complications. The histopathological study showed a high grade non-muscle invasive urothelial carcinoma of the distal ureter (pT1NxMx) with negative margins. Conclusions: The distal radical ureterectomy with Boari replacement is feasible and more precise with robotic assistance. Its oncological role must be demostrated with a larger number of cases.Objetivo: Comunicar un caso de tumor ureteral distal tratado con ureterectomía radical y neoimplante vesicoureteral con técnica de Flap Boari asistida por robot. Material y Métodos: Paciente hombre de 55 años, con diagnóstico de carcinoma urotelial de uréter distal sin compromiso multifocal. Resultados: Se realizó ureterectomía distal radical y neoimplante vesicoureteral con Flap Boari asistido por Robot da Vinci S-HD. El tiempo operatorio fue de 210 minutos, con un sangrado estimado de 200 ml. La estadía hospitalaria fue de 48 horas, sin complicaciones perioperatorias. El estudio histológico mostró un carcinoma urotelial de alto grado con infiltración de la lámina propia (pT1NxMx) y márgenes quirúrgicos negativos. Conclusiones: La ureterectomía radical distal con reconstrucción tipo Boari es técnicamente factible y más precisa con la asistencia robótica. Su rol oncológico requiere de validación con mayor número de casos.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-40262011000400013&nrm=is

    ANÁLISIS INFORME CONTINUIDAD DE CUIDADOS SEGÚN CRITERIO ENFERMERO.

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    Consensuar qué pacientes deben salir del Hospital con Informe Continuidad de Cuidados es una discusión sin solucionar dentro del foro enfermero, y cada vez son más las voces que avalan que debe ponderar el criterio enfermero y la situación específica del paciente. Objetivos:Analizar el perfil de los pacientes que salen del Hospital con Informe Continuidad de Cuidados identificando las indicaciones más prevalentes. Ver el número total de altas con Informe Continuidad de Cuidados estratificado por especialidades. Metodología: Estudio observacional descriptivo cualitativo y cuantitativo, analizando todos los informes realizados de septiembre a diciembre de 2006 en unidades Médico-Quirúrgicas. Metodología cualitativa y cuantitativa. Fuente de datos: Servidor Gestión pacientes/Gestión de cuidados e Informe de Continuidad de Cuidados. Resultados: Cuantitativos: Emitidos 234 informes sobre un total de 676 altas, supone un 35% de pacientes con Informe de Continuidad de Cuidados. El 59,4% corresponden al área médica y el 40,5% quirúrgica, siendo Urología (57%) la unidad con más informes. Cualitativos: El 57% son mujeres y el 78% mayores de 65 años. Necesidades humanas no cubiertas más prevalentes: Movilidad 29%, Piel/Mucosa 28%, Eliminación 14%, Oxigenación/Respiración 12%, Nutrición 10%, Aprendizaje 7%.. Se presentan las situaciones y diagnósticos al alta más prevalentes. Conclusiones: Tras revisión bibliográfica, el porcentaje de pacientes con Informe de Continuidad de Cuidados es alto en nuestra área (35%). Perfil: podemos decir mujer, mayor de 65 años, con deterioro importante en la movilidad e intolerancia a la actividad (encamado), con UPP o herida quirúrgica, con anticoagulantes por vía subcutánea, insulinodependiente, con sonda vesical y/o sonda nasogástrica

    Breeding ecology of the southern shrike (Lanius meridionalis) in an agrosystem of south-eastern Spain: The surprisingly excellent breeding success in a declining population

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    The southern shrike (Lanius meridionalis) is declining at the Spanish and European level. One cause of this decline could be low reproductive success due to low availability of prey in agricultural environments. To investigate this possibility we analysed the breeding ecology of a population of southern shrike in an agrosystem in Lomas de Padul (SE Spain). Our results suggestthe population is declining in this area. However, contrary to expectations, the population showed the highest reproductive success (% nests in which at least one egg produces a fledgling) reported for this species to date (83.3%), with a productivity of 4.04 fledglings per nest. Reproductive success varied throughout the years, ranging from 75% in the worst year to 92.9% in the best year. Similarly, productivity ranged from 3.25 to 5.0 fledglings per nest depending on the year. Other aspects of reproductive biology, such as clutch size, brood size, and nestling diet, were similar to those reported in other studies. Based on these results, we hypothesise that the determinant of population decline acts on the juvenile fraction, drastically reducing the recruitment rate, or affecting the dispersion of adults and recruits. Nevertheless, the exact factor or factors are unknown. This study shows that a high reproductive success does not guarantee good health status of the population.Peer Reviewe

    Artificial intelligence in wind speed forecasting: a review

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    Wind energy production has had accelerated growth in recent years, reaching an annual increase of 17% in 2021. Wind speed plays a crucial role in the stability required for power grid operation. However, wind intermittency makes accurate forecasting a complicated process. Implementing new technologies has allowed the development of hybrid models and techniques, improving wind speed forecasting accuracy. Additionally, statistical and artificial intelligence methods, especially artificial neural networks, have been applied to enhance the results. However, there is a concern about identifying the main factors influencing the forecasting process and providing a basis for estimation with artificial neural network models. This paper reviews and classifies the forecasting models used in recent years according to the input model type, the pre-processing and post-processing technique, the artificial neural network model, the prediction horizon, the steps ahead number, and the evaluation metric. The research results indicate that artificial neural network (ANN)-based models can provide accurate wind forecasting and essential information about the specific location of potential wind use for a power plant by understanding the future wind speed values

    Bondian frames to couple matter with radiation

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    A study is presented for the non linear evolution of a self gravitating distribution of matter coupled to a massless scalar field. The characteristic formulation for numerical relativity is used to follow the evolution by a sequence of light cones open to the future. Bondian frames are used to endow physical meaning to the matter variables and to the massless scalar field. Asymptotic approaches to the origin and to infinity are achieved; at the boundary surface interior and exterior solutions are matched guaranteeing the Darmois--Lichnerowicz conditions. To show how the scheme works some numerical models are discussed. We exemplify evolving scalar waves on the following fixed backgrounds: A) an atmosphere between the boundary surface of an incompressible mixtured fluid and infinity; B) a polytropic distribution matched to a Schwarzschild exterior; C) a Schwarzschild- Schwarzschild spacetime. The conservation of energy, the Newman--Penrose constant preservation and other expected features are observed.Comment: 20 pages, 6 figures; to appear in General Relativity and Gravitatio

    Objectives, organization and limiting factors of selection programs for indigenous breeds in Spain

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    Ponencia publicada en ITEA, vol.104En esta ponencia invitada se resumen las principales características de los programas de selección de las razas autóctonas que se están llevando a cabo en España. Se describen para cada una de ellas la población controlada, los caracteres registrados, los objetivos y criterios de selección, la valoración genética de los reproductores, los aspectos organizativos, la utilización de la información por parte de los ganaderos y los factores limitantes del progreso genético. Los más antiguos de estos programa comenzaron al principio de la década de los 80 del pasado siglo, la mayoría lo hicieron al final de dicha década o en la siguiente y unos pocos en la década actual. Debido a esta disparidad de fechas de iniciación y a otros factores estructurales y organizativos, sus niveles de desarrollo y efectividad son muy variables. Entre los factores limitantes de dicho desarrollo y efectividad más frecuentemente citados se encuentran los reducidos tamaños de los núcleos de selección, la reducida implantación de la I.A. y, consecuentemente, el bajo número de sementales en prueba de descendencia y las bajas fiabilidades de las valoraciones genéticas, la escasa utilización por parte algunos de los ganaderos de las valoraciones genéticas de sus animales para elegir la reposición en los rebaños y, en un cierto número de casos, la escasa participación e interés de los mismos.This invited contribution summarizes the most important characteristics of selection programs being applied to Spanish indigenous breeds. Population and traits being recorded, selection objectives and criteria, breeding values estimation, managing aspects, diffusion to and use of genetic information by breeders and constraints to genetic progress are synthetically described for each breed. The oldest programs started at the beginning of the eighties of the last century. Most of them began at the end of the eighties or in the nineties and a few were initiated within present decade. Due to these age differences, and to other structural and managing factors, their developmental and effectiveness levels are very variable. Small number of animals being registered and, therefore, selected, low number of dams inseminated an its consequence on the capacity to sire testing and on the reliability of estimated breeding values, the scanty use that some of the breeders make of the genetic evaluations and the low participation of farmers in the programs, are among the most important factors limiting their development and their effectiveness in terms of genetic progress obtained

    Microsystem-assisted synthesis of carbon dots with fluorescent and colorimetric properties for pH detection

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    The present paper describes the use of a microfluidic system to synthesize carbon dots (Cdots) and their use as optical pH sensors. The synthesis is based on the thermal decomposition of ascorbic acid in dimethyl sulfoxide. The proposed microsystem is composed of a fluidic and a thermal platform, which enable proper control of synthesis variables. Uniform and monodispersed 3.3 nm-sized Cdots have been synthesized, the optical characterization of which showed their down/upconversion luminescence and colorimetric properties. The obtained Cdots have been used for pH detection with down and upconverison fluorescent properties as excitation sources. The naked eye or a photographic digital camera has also been implemented as detection systems with the hue parameter showing a linear pH range from 3.5 to 10.2. On the other hand, experiments on the cytotoxicity and permeability of the Cdots on human embryonic kidney cells revealed their adsorption on cells without causing any impact on the cellular morphology.This work was supported by Projects SGR 2009-0323 from Catalonia Government and P10-FQM-5974 from the Junta de Andalucía (Spain). These projects were partially supported by European Regional Development Funds (ERDF). Our thanks to “Reincorporacion de Doctores UGR” programs and Greib startu

    Modulo RFID de Acceso para oficinas

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    En la oficina de la empresa Kimbaya Technology S.A.S existía la necesidad de implementar un sistema de acceso automático que optimizara el tiempo y las funciones de sus empleados. Por ello, se desarrollo un control de acceso, un módulo con la tecnología RFID en el que cada funcionario de la oficina cuenta con su propio Tag o tarjeta RFID UHF tipo carné, el cual posee un código específico y único. Debido a que se trabajó con UHF, el sistema permite una lectura a una distancia entre 60 cm y 1 m, sin necesidad de que exista una proximidad estrecha entre el lector y el Tag
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