96 research outputs found

    Optimal Operation of Pipeline Transportation Systems

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    11th Triennial World Congress. Tallinn. Estonia. USSR. 1990This paper presents a simulator of an oil pipeline for scheduling purposes. The simulator includes an algorithm for optimizing the energy operating costs. The optimization algorithm works in two steps. The first one consists of the computation of a function that measures the estimated mininltun cost to the goal node. This computation involves the use of Bellman's optimality principle and of some heuristic rules in order to avoid the combinatorial explosion. During the second step the optinltmum trajectory is obtained with the help of the function mentioned above and using an accurate simulation of the transportation system. The simulation considers those aspects which are relevant t.o the optimization problem and takes into account the following factors: topology and topography of the network. non-linear characteristics of pumps and pipelines, variable demands of consumers, time changing prices of electrical energy and hydraulic equations throughout the system. The simulator is being used by CAMPSA (the major oil distribution company in Spain) Some results obtained with an oil pipeline system in Northern Spain are presented in the paper

    Comunicación organizacional en las oficinas del RENIEC de la zona sur - Lima 2018

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    La investigación presentada tuvo como objetivo determinar cuál es el nivel de comunicación organizacional en las oficinas del Reniec de la Zona Sur de Lima, siendo la autora Vanessa Guzmán, quien sostiene la teoría de fundamentación del estudio proponiendo la necesidad de evaluar las redes y flujos de la comunicación. El marco metodológico del estudio señala que es de tipo aplicada, con un diseño no experimental, de nivel descriptivo, de enfoque cuantitativo, y con una población y muestra conformada por 40 personas de las oficinas registrales de la zona sur del Reniec de lima, para la cual se utilizó la técnica de la encuesta para la recolección de datos, aplicando como instrumento el cuestionario en la escala de Likert. Finalmente se concluye la investigación, determinando que el nivel de comunicación organizacional en las oficinas del Reniec de la zona sur de lima se encuentra en un nivel medio

    Physical and respiratory therapy in the critically ill patient with obesity: a narrative review

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    Obesity has become increasingly prevalent in the intensive care unit, presenting a significant challenge for healthcare systems and professionals, including rehabilitation teams. Caring for critically ill patients with obesity involves addressing complex issues. Despite the well-established and safe practice of early mobilization during critical illness, in rehabilitation matters, the diverse clinical disturbances and scenarios within the obese patient population necessitate a comprehensive understanding. This includes recognizing the importance of metabolic support, both non-invasive and invasive ventilatory support, and their weaning processes as essential prerequisites. Physiotherapists, working collaboratively with a multidisciplinary team, play a crucial role in ensuring proper assessment and functional rehabilitation in the critical care setting. This review aims to provide critical insights into the key management and rehabilitation principles for obese patients in the intensive care unit

    Performance of ejector refrigeration cycle using a steady flow model

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    A study of an alternative ejector cooling system is proposed in this paper. A mathematical model without irreversibility is developed and simulated. The numerical results are validated with literature data for two working fluids (R134a and R152a). The performance and behavior of the system using conventional refrigerants (HFC’s, HC's) and unconventional (R717, R718) is obtained; the process uses 100 kW of heat available in a waste stream. Finally, the paper explores the reduction of problems associated with the use of conventional refrigerants by introducing the use of R718 (water) as the working fluid of the proposed system

    Bioactives Overproduction through Operational Strategies in the Ichthyotoxic Microalga Heterosigma akashiwo Culture

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    The red tide-forming microalga Heterosigma akashiwo has been associated with massive events of fish deaths, both wild and cultured. Culture conditions are responsible for the synthesis or accumulation of some metabolites with different interesting bioactivities. H. akashiwo LC269919 strain was grown in a 10 L bubble column photobioreactor artificially illuminated with multi-coloured LED lights. Growth and production of exopolysaccharides, polyunsaturated fatty acids (PUFAs), and carotenoids were evaluated under different culture modes (batch, fed-batch, semicontinuous, and continuous) at two irradiance levels (300 and 700 µE·s−1·m−2). Continuous mode at the dilution rate of 0.2·day−1 and 700 µE·s−1·m−2 provided the highest production of biomass, PUFAs (132.6 and 2.3 mg·L−1·day−1), and maximum fucoxanthin productivity (0.16 mg·L−1·day−1). The fed-batch mode accumulated exopolysaccharides in a concentration (1.02 g·L−1) 10-fold over the batch mode. An extraction process based on a sequential gradient partition with water and four water-immiscible organic solvents allowed the isolation of bioactive fucoxanthin from methanolic extracts of H. akashiwo. Metabolites present in H. akashiwo, fucoxanthin and polar lipids (i.e., eicosapentaenoic acid (EPA)), or probably such as phytosterol (β-Sitosterol) from other microalgae, were responsible for the antitumor activity obtained.This research was funded by the General Secretariat of Universities, Research and Technology of the Andalusian Government (grant: P18-RT-2477) and the State Research Agency (grants PID2019-109476RB-C22) of the Spanish Ministry of Science, Innovation and Universities

    Equipo robotizado para la localización de artículos en una tienda y su procedimiento de funcionamiento

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    Equipo robotizado para la localización de artículos en una tienda y su procedimiento de funcionamiento. Equipo robotizado para la localización de artículos en coordenadas XYZ en una tienda que consta de un robot móvil (1) y puede comprender opcionalmente un ordenador externo (2) conectado por vía inalámbrica con el robot (1), que a su vez está formado por un sistema de visión artificial (3), un sistema de barrido y detección de obstáculos (4), un sistema de lectura de etiquetas activas con señales ópticas y/o electromagnéticas (5), un sistema de desplazamiento (11) formado por al menos dos ruedas motrices, una batería (6) y un controlador (7) que comprende una placa principal con un sistema operativo de código abierto, estando conectado dicho controlador con los diferentes sistemas que conforman el robot y estando configurado para recibir datos de dichos sistemas y procesarlos con objeto de crear un mapa de la tienda y determinar la ubicación de cada artículo en la tienda.Españ

    Groundwater abstraction has caused extensive ecological damage to the Doñana World Heritage Site, Spain

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    Se incluye información suplementaria.Acreman et al. (2022) reviewed evidence for ecological damage to the Doñana wetlands (UNESCO World Heritage Site [WHS] and Ramsar site), Spain, associated with intensification of groundwater use, particularly for agriculture. Acreman et al. presented a multistep methodology for evidence-based risk assessment that involves identification of conservation issues, and a systematic review of scientific evidence for ecological damage and its causes. However, they involved few local scientists, used a questionable methodology in stakeholder selection and involvement, used a flawed conceptual framework, and an incomplete literature review. We propose improvements to their methodology. They overlooked or misinterpreted key evidence, and underestimated the impacts that abstraction for irrigation for red fruits (mainly strawberries), rice and other crops has had on Doñana and its biodiversity. They reported groundwater level depletion of up to 10 m in the deep aquifer, but wrongly concluded that there is no evidence for impacts on the natural marsh ecosystem, the dune ponds or the ecotone. Groundwater drawdowns are actually up to 20 m, and have inverted the formerly ascending vertical hydraulic gradient in discharge areas. Phreatic levels have been lowered from 0.5 to 2 m in some areas. Groundwater abstraction has caused multiple ecological impacts to temporary ponds and marshes in the WHS, as well as to terrestrial vegetation, and should be urgently reduced. Furthermore, Acreman et al. focused on groundwater quantity while overlooking the importance of severe impacts on quality of both surface and groundwater, intimately connected to the use of agrochemicals for irrigated crops.Part of this work (marsh hydroperiod and water depth) has been funded by eLTER Plus project (INFRAIA, Horizon 2020, Agreement No 871128) and FEDER actions [SUMHAL, LIFEWATCH-2019-09-CSIC-13, POPE 2014-2020] by the Ministry of Science, Innovation and Universities, Subtask LWE2103022: Integration into VRE in the framework of the CSIC Interdisciplinary Thematic Platforms (PTI) PTI EcoBioDiv and Teledetect. PMRG was funded by the Portuguese Foundation for Science and Technology (FCT), through the Individual Stimulus to Scientific Employment Programme with the 2020.03356.CEECIND grant, and Forest Research Centre by the FCT (UIDB/00239/2020) grant.N

    Sociodemographic, clinical and laboratory factors on admission associated with COVID19 mortality in hospitalized patients: A retrospective observational study

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    Background To identify and quantify associations between baseline characteristics on hospital admission and mortality in patients with COVID-19 at a tertiary hospital in Spain. Methods and findings This retrospective case series included 238 patients hospitalized for COVID-19 at Hospital Universitario Clı´nico San Cecilio (Granada, Spain) who were discharged or who died. Electronic medical records were reviewed to obtain information on sex, age, personal antecedents, clinical features, findings on physical examination, and laboratory results for each patient. Associations between mortality and baseline characteristics were estimated as hazard ratios (HR) calculated with Cox regression models. Series mortality was 25.6%. Among patients with dependence for basic activities of daily living, 78.7% died, and among patients residing in retirement homes, 80.8% died. The variables most clearly associated with a greater hazard of death were age (3% HR increase per 1-year increase in age; 95%CI 1–6), diabetes mellitus (HR 2.42, 95%CI 1.43–4.09), SatO2/ FiO2 ratio (43% HR reduction per 1-point increase; 95%CI 23–57), SOFA score (19% HR increase per 1-point increase, 95%CI 5–34) and CURB-65 score (76% HR increase per 1- point increase, 95%CI 23–143). Conclusions The patients residing in retirement homes showed great vulnerability. The main baseline factors that were independently associated with mortality in patients hospitalized for COVID-19 were older age, diabetes mellitus, low SatO2/FiO2 ratio, and high SOFA and CURB-65 scores.Fondos Estructurales de la Union Europea (FEDER)Unit of Excellence on Exercise and Health (UCEES), University of Granad

    Anexo II. Fichas de los ítems

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    El presente documento contiene uno de los anexos a la publicación impresa titulada "Recuperando la ciudad. Estrategia para el diseño y la evaluación de planes y programas de regeneración urbana integrada" —ISBN: 978-84-9728-5585-1— libro que es uno de los resultados obtenidos del proyecto financiado por el Plan Nacional I+D+i para el periodo 2013-2015, titulado "Estrategia para el diseño y evaluación de planes y programas de regeneración urbana integrada. La intervención en las periferias españolas a través de las áreas de rehabilitación integral y el programa URBAN" (BIA2012-31905). Dicho proyecto se ha realizado en el Departamento de Urbanística y Ordenación del Territorio de la Escuela Técnica Superior de Arquitectura de Madrid, mediante la financiación del Ministerio de Economía y Competitividad, a través del Plan Nacional de I+D+i 2008-2011 (Subprograma de Proyectos de Investigación Fundamental no Orientada). En este segundo anexo se realiza una caracterización y descripción de cada uno de los ítems que forman parte cada una de las categorías pertenecientes a las cuatro áreas principales, facilitando así el uso de la herramienta en los casos en los que se requiera de un mayor nivel de detalle
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