846 resultados para Total Flow Management


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Analizar las relaciones existentes dentro del entorno marcado por la educación física entre cuatro factores claramente diferenciados: la motivación del alumno hacia las clases, la que genera el profesor, los comportamientos disciplinados e indisciplinados, la percepción de la igualdad en el trato entre chicos y chicas y el flow disposicional mostrado en la mejor experiencia sentida por el alumno en sus clases. . Población de estudiantes de primer ciclo de ESO de la Comunidad Valenciana. Muestra compuesta por un total de 1103 alumnos pertenecientes al segundo curso de ESO de centros públicos y privados de la provincia de Alicante. Los instrumentos empleados para recoger la información son: Cuestionario de Percepción del Éxito (Cervelló, Escartí y Balagué, 1999); Instrumento de Medición del Clima Motivacional en las Clases de Educación Física (Cervelló, Moreno, Del Villar y Reina, 2006); Cuestionario de Conductas de Disciplina-Indisciplina en Educación Física (Cervelló, Jiménez, Nerea, Ramos, Del Villar y Santos-Rosa, 2002); Cuestionario de Percepción de Igualdad-Discriminación en Educación Física (Cervelló, Jiménez, Del Villar, Ramos y Santos-Rosa, 2004); Escala de Flow Dispocicional (Jackson, 2000. Traducida por Cervelló, Nerea, Jiménez, García-Calvo y santos-Rosa, 2001). Se utilizó el análisis factorial de componentes principales con rotación varimax para todos los cuestionarios con el fin de determinar su estructura. Se aplica el análisis de correlación para descubrir las relaciones entre variables del estudio. El análisis jerárquico de cluster para identificar los perfiles motivacionales de los alumnos que componen la muestra de estudio atendiendo a las variables de orientación disposicional, clima motivacional percibido, disciplina, coeducación y flow disposicional y el análisis de ecuaciones estructurales para testar los modelos teóricos de la investigación.. Es de vital importancia que el profesor de educación física cree un adecuado clima motivacional implicante en la tarea porque será así facilitador de un trato justo y ecuánime hacia todos sus alumnos, generador de un buen ambiente de clase debido al buen comportamiento de sus discentes ocasionado por la preocupación de éstos hacia el aprendizaje de la materia impartida y fomentador de un estado psicológico óptimo que le ayude a concentrar su atención sobre la actividad a realizar obteniendo como resultado una experiencia enriquecedora y satisfactoria..

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La present tesi proposa una metodologia de disseny conceptual d'estacions depuradores d'aigües residuals (EDAR) mitjançant la combinació del procés de decisió jeràrquic i l'anàlisi de decisions multicriteri. El document s'inicia amb una breu introducció als principals camps abordats pel treball: el disseny dels processos químics en general, el disseny de les estacions depuradores d'aigües residuals en particular, i l'anàlisi de decisions multicriteri aplicada a la gestió ambiental. Seguidament, es fixen els objectius del treball i es descriuen tant la metodologia com el material de suport informàtic utilitzats. Per validar i contrastar la metodologia de disseny presentada, es desenvolupa un cas d'estudi on es porta a terme el disseny conceptual d'una EDAR que presenta els mateixos requeriments que l'EDAR que opera actualment al municipi de Granollers. Inicialment es presenta la informació de partida i tot seguit es defineixen els objectius de disseny, així com el conjunt de criteris que s'utilitzaran per avaluar en quina mesura es compleixen aquests objectius. Els objectius de disseny són de diferents tipus: ambientals, tècnics, socials i econòmics, i el conjunt de criteris utilitzats, concretament 33, també es classifica segons aquestes quatre categories. Cadascun dels criteris presenta un determinat pes d'importància relativa en la presa de decisions. Finalment, es desenvolupa tot el procés de decisió fins a obtenir el disseny complet de l'EDAR. El procés de decisió s'ha dividit en dues parts diferenciades però que alhora s'entrellacen: la línia d'aigua i la línia de fang. El procés de decisió presenta un total de divuit qüestions amb un màxim de quatre alternatives per pregunta (dotze qüestions corresponen a la línia d'aigua, i sis a la línia de fangs). Per solucionar cadascuna d'aquestes qüestions, s'avaluen les alternatives proposades respecte a un conjunt de criteris triats de la llista inicial. Aplicant el procés de decisió multicriteri anomenat SMART (simple multiattribute rating technique), es combinen els resultats de les alternatives respecte a cada criteri, tenint en compte la importància de cada criteri per obtenir un sol valor per alternativa. Per quantificar els criteris referents a l'operació del procés i les de tipus econòmic s'han utilitzat els programes GPS-X i CapdetWorks respectivament. Pel que fa als criteris no quantificats mitjançant aquests programes, s'han resolt de manera qualitativa i mitjançant manuals de disseny i també tenint en compte l'opinió d'experts en aquest camp. L'alternativa que obté un pes més elevat és la recomanada per al procés de decisió. El cas d'estudi finalitza un cop s'obté el disseny complet de l'EDAR. Per integrar tots aquests elements que hem esmentat i donar suport al desenvolupament del procés de decisió s'ha utilitzat el programa DRAMA (Design Rationale Management). A continuació, es fa una anàlisi comparativa entre l'EDAR que hi ha actualment al municipi de Granollers i l'EDAR resultat del cas d'estudi. Es descriu el diagrama de flux que conforma l'EDAR de Granollers i el diagrama de flux de l'EDAR resultat de l'estudi, se'n fa una anàlisi comparativa justificant cadascuna de les decisions preses en el cas d'estudi i, finalment, es fa una discussió de resultats on es reflecteixen els avantatges associats d'aplicar la metodologia de disseny conceptual proposada. Finalment, es presenten les conclusions de la tesi. Els principals resultats de la tesi es van publicar el 2002 a la revista internacional Industrial and Engineering Chemistry Research (N. Vidal, R. Bañares-Alcántara, I. Rodríguez-Roda i M. Poch: "Design of wastewater treatment plants using a conceptual design methodology", Industrial and Engineering Chemistry Research, 41 (20), pàg. 4993-5005) i la continuació de la línia de recerca al Laboratori d'Enginyeria Química i Ambiental de la UdG ha comportat la presentació del treball de recerca de Xavi Flores "Procés de decisió jeràrquic combinat amb anàlisi multicriteri per al suport al disseny conceptual de sistemes de fangs actius d'una estació depuradora d'aigües residuals" i la presentació dels resultats parcials al congrés internacional de la 9th IWA Conference on Design, Operation and Economics of Large Wastewater Treatment, que va tenir lloc el setembre passat a Praga ("Combining hierarchical decision process with multi-criteria analysis for conceptual design of WWTP", X. Flores, N. Vidal, A. Bonmatí, J. B. Copp i I. Rodríguez-Roda).

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Este estudo procura investigar possíveis associações entre as experiências de flow e os fenómenos de mentoria e liderança. Procura-se identificar as características e benefícios de experiências de flow e de relações de mentoria e liderança, percebidos pelos colaboradores de quatro empresas de Injeção de Plásticos da Marinha Grande. Identificam-se as funções de mentoria, os estilos de liderança transacional, transformacional e servidora e os componentes de flow entre estes colaboradores. Para a medição dos estilos de liderança foram utilizados os instrumentos desenvolvidos por Avolio e Bass (2004) e Dennis (2004). Para as funções das relações de mentoria, definidas por Ragins e Kram (2007), o instrumento desenvolvido por Noe (1988). Para os componentes observados em experiências de flow, o instrumento desenvolvido por Jackson e Ecklund (2002). Apoiado nos instrumentos referidos foi aplicado um questionário na recolha dos dados para este estudo. Foram encontradas influências moderadas e fortes entre os estilos de liderança, as funções de mentoria e os componentes de uma experiência de flow.

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The impact of targeted sonde observations on the 1-3 day forecasts for northern Europe is evaluated using the Met Office four-dimensional variational data assimilation scheme and a 24 km gridlength limited-area version of the Unified Model (MetUM). The targeted observations were carried out during February and March 2007 as part of the Greenland Flow Distortion Experiment, using a research aircraft based in Iceland. Sensitive area predictions using either total energy singular vectors or an ensemble transform Kalman filter were used to predict where additional observations should be made to reduce errors in the initial conditions of forecasts for northern Europe. Targeted sonde data was assimilated operationally into the MetUM. Hindcasts show that the impact of the sondes was mixed. Only two out of the five cases showed clear forecast improvement; the maximum forecast improvement seen over the verifying region was approximately 5% of the forecast error 24 hours into the forecast. These two cases are presented in more detail: in the first the improvement propagates into the verification region with a developing polar low; and in the second the improvement is associated with an upper-level trough. The impact of cycling targeted data in the background of the forecast (including the memory of previous targeted observations) is investigated. This is shown to cause a greater forecast impact, but does not necessarily lead to a greater forecast improvement. Finally, the robustness of the results is assessed using a small ensemble of forecasts.

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There have been only a few studies of potassium (K) losses from grassland systems, and little is known about their dynamics, especially in relation to nitrogen (N) management. A study was performed during the autumn and winter of 1999 and 2000 to understand the effects of N and drainage on the dynamics of K leaching on a hillslope grassland soil in southwestern England. Two N application rates were studied (0 and 280 kg N ha(-1) yr(-1)), both with and without the drainage. Treatments receiving N also received farmyard manure (FM). Higher total K losses and K concentrations in the leachates were found in the N + FM treatments (150 and 185% higher than in 0 N treatments), which were related to K additions in the FM. Drainage reduced K losses by 35% because of an increase in dry matter production and a reduction in overland and preferential flow. The pattern of change in K concentration in the leachates was associated with preferential flow at the beginning of the drainage season and with matrix flow later in winter, and was best described by a double exponential curve. Rainfall intensity and the autumn application of FM were the main determinants of K losses by leaching. The study provided new insights into the relationships between soil hydrology, rainfall, and K leaching and its implications for grassland systems.

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A set of lysimeter based experiments was carried out during 2000/01 to evaluate the impact of soil type and grassland management on potassium (K) leaching. The effects of (1) four soil textures (sand, loam, loam over chalk and clay), (2) grazing and cutting (with farmyard manure application), and (3) K applied as inorganic fertilizer, dairy slurry or a mixture of both sources were tested. Total K losses in the clay soil were more than twice those in the sand soil (13 and 6 kg K ha(-1), respectively) because of the development of preferential flow in the clay soil. They were also greater in the cut treatment than in the grazed treatment (82 and 51 kg K ha(-1), respectively; P less than or equal to0.01), associated with a 63% increase of K concentration in the leachates from the former (6.7 +/- 0.28 and 4.1 +/- 0.22 mg K L-1 for cut and grazed, respectively; P less than or equal to0.01) because of the K input from the farmyard manure. The source of fertilizer did not affect total K losses or the average K concentration in the leachates (P >0.05), but it changed the pattern of these over time.

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The aim of this study was to examine interrelationships between functional biochemical and microbial indicators of soil quality, and their suitability to differentiate areas under contrasting agricultural management regimes. The study included five 0.8 ha areas on a sandy-loam soil which had received contrasting fertility and cropping regimes over a 5 year period. These were organically managed vegetable, vegetable -cereal and arable rotations, an organically managed grass clover ley, and a conventional cereal rotation. The organic areas had been converted from conventional cereal production 5 years prior to the start of the study. All of the biochemical analyses, including light fraction organic matter (LFOM) C and N, labile organic N (LON), dissolved organic N and water-soluble carbohydrates showed significant differences between the areas, although the nature of the relationships between the areas varied between the different parameters, and were not related to differences in total soil organic matter content. The clearest differences were seen in LFOM C and N and LON, which were higher in the organic arable area relative to the other areas. In the case of the biological parameters, there were differences between the areas for biomass-N, ATP, chitin content, and the ratios of ATP: biomass and basal respiration: biomass. For these parameters, the precise relationships between the areas varied. However, relative to the conventionally managed area, areas under organic management generally had lower biomass-N and higher ATP contents. Arbuscular mycorrhizal fungus colonization potential was extremely low in the conventional area relative to the organic areas. Further, metabolic diversity and microbial community level physiological profiles, determined by analysis of microbial community metabolism using Biolog GN plates and the activities of eight key nutrient cycling enzymes, grouped the organic areas together, but separated them from the conventional area. We conclude that microbial parameters are more effective and consistent indicators of management induced changes to soil quality than biochemical parameters, and that a variety of biochemical and microbial analyses should be used when considering the impact of management on soil quality. (C) 2004 Elsevier Ltd. All rights reserved.

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In the UK, the recycling of sewage sludge to land is expected to double by 2006 but the security of this route is threatened by environmental concerns and health scares. Strategic investment is needed to ensure sustainable and secure sludge recycling outlets. At present, the security of this landbank for sludge recycling is determined by legislation relating to nutrient rather than potentially toxic elements (PTEs) applications to land - especially the environmental risk linked to soil phosphorus (P) saturation. We believe that not all land has an equal risk of contributing nutrients derived from applications to land to receiving waters. We are currently investigating whether it is possible to minimise nutrient loss by applying sludge to land outside Critical Source Areas (CSAs) regardless of soil P Index status. Research is underway to develop a predictive and spatially-sensitive, semi-distributed model of critical thresholds for sludge application that goes beyond traditional 'end-of-pipe" or "edge-of-field" modelling, to include hydrological flow paths and delivery mechanisms to receiving waters from non-point sources at the catchment scale.

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The interpretation of soil water dynamics under drip irrigation systems is relevant for crop production as well as on water use and management. In this study a three-dimensional representation of the flow of water under drip irrigation is presented. The work includes analysis of the water balance at point scale as well as area-average, exploring uncertainties in water balance estimations depending on the number of locations sampled. The water flow was monitored by detailed profile water content measurements before irrigation, after irrigation and 24 h later with a dense array of soil moisture access tubes radially distributed around selected drippers. The objective was to develop a methodology that could be used on selected occasions to obtain 'snap shots' of the detailed three-dimensional patterns of soil moisture. Such patterns are likely to be very complex, as spatial variability will be induced for a number of reasons, such as strong horizontal gradients in soil moisture, variations between individual sources in the amount of water applied and spatial variability is soil hydraulic properties. Results are compared with a widely used numerical model, Hydrus-2D. The observed dynamic of the water content distribution is in good agreement with model simulations, although some discrepancies concerning the horizontal distribution of the irrigation bulb are noted due to soil heterogeneity. (c) 2006 Elsevier B.V. All rights reserved.

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A multi-scale framework for decision support is presented that uses a combination of experiments, models, communication, education and decision support tools to arrive at a realistic strategy to minimise diffuse pollution. Effective partnerships between researchers and stakeholders play a key part in successful implementation of this strategy. The Decision Support Matrix (DSM) is introduced as a set of visualisations that can be used at all scales, both to inform decision making and as a communication tool in stakeholder workshops. A demonstration farm is presented and one of its fields is taken as a case study. Hydrological and nutrient flow path models are used for event based simulation (TOPCAT), catchment scale modelling (INCA) and field scale flow visualisation (TopManage). One of the DSMs; The Phosphorus Export Risk Matrix (PERM) is discussed in detail. The PERM was developed iteratively as a point of discussion in stakeholder workshops, as a decision support and education tool. The resulting interactive PERM contains a set of questions and proposed remediation measures that reflect both expert and local knowledge. Education and visualisation tools such as GIS, risk indicators, TopManage and the PERM are found to be invaluable in communicating improved farming practice to stakeholders. (C) 2008 Elsevier Ltd. All rights reserved.

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The unsaturated zone exerts a major control on the delivery of nutrients to Chalk streams, yet flow and transport processes in this complex, dual-porosity medium have remained controversial. A major challenge arises in characterising these processes, both at the detailed mechanistic level and at an appropriate level for inclusion within catchment-scale models for nutrient management. The lowland catchment research (LOCAR) programme in the UK has provided a unique set of comprehensively instrumented groundwater-dominated catchments. Of these, the Pang and Lambourn, tributaries of the Thames near Reading, have been a particular focus for research into subsurface processes and surface water-groundwater interactions. Data from LOCAR and other sources, along with a new dual permeability numerical model of the Chalk, have been used to explore the relative roles of matrix and fracture flow within the unsaturated zone and resolve conflicting hypotheses of response. From the improved understanding gained through these explorations, a parsimonious conceptualisation of the general response of flow and transport within the Chalk unsaturated zone was formulated. This paper summarises the modelling and data findings of these explorations, and describes the integration of the new simplified unsaturated zone representation with a catchment-scale model of nutrients (INCA), resulting in a new model for catchment-scale flow and transport within Chalk systems: INCA-Chalk. This model is applied to the Lambourn, and results, including hindcast and forecast simulations, are presented. These clearly illustrate the decadal time-scales that need to be considered in the context of nutrient management and the EU Water Framework Directive. (C) 2007 Elsevier B.V. All rights reserved.

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This paper analyses historic records of agricultural land use and management for England and Wales from 1931 and 1991 and uses export coefficient modelling to hindcast the impact of these practices on the rates of diffuse nitrogen (N) and phosphorus (P) export to water bodies for each of the major geo-climatic regions of England and Wales. Key trends indicate the importance of animal agriculture as a contributor to the total diffuse agricultural nutrient loading on waters, and the need to bring these sources under control if conditions suitable for sustaining 'Good Ecological Status' under the Water Framework Directive are to be generated. The analysis highlights the importance of measuring changes in nutrient loading in relation to the catchment-specific baseline state for different water bodies. The approach is also used to forecast the likely impact of broad regional scale scenarios on nutrient export to waters and highlights the need to take sensitive land out of production, introduce ceilings on fertilizer use and stocking densities, and controls on agricultural practice in higher risk areas where intensive agriculture is combined with a low intrinsic nutrient retention capacity, although the uncertainties associated with the modelling applied at this scale should be taken into account in the interpretation of model output. The paper advocates the need for a two-tiered approach to nutrient management, combining broad regional policies with targeted management in high risk areas at the catchment and farm scale.

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Across Europe, elevated phosphorus (P) concentrations in lowland rivers have made them particularly susceptible to eutrophication. This is compounded in southern and central UK by increasing pressures on water resources, which may be further enhanced by the potential effects of climate change. The EU Water Framework Directive requires an integrated approach to water resources management at the catchment scale and highlights the need for modelling tools that can distinguish relative contributions from multiple nutrient sources and are consistent with the information content of the available data. Two such models are introduced and evaluated within a stochastic framework using daily flow and total phosphorus concentrations recorded in a clay catchment typical of many areas of the lowland UK. Both models disaggregate empirical annual load estimates, derived from land use data, as a function of surface/near surface runoff, generated using a simple conceptual rainfall-runoff model. Estimates of the daily load from agricultural land, together with those from baseflow and point sources, feed into an in-stream routing algorithm. The first model assumes constant concentrations in runoff via surface/near surface pathways and incorporates an additional P store in the river-bed sediments, depleted above a critical discharge, to explicitly simulate resuspension. The second model, which is simpler, simulates P concentrations as a function of surface/near surface runoff, thus emphasising the influence of non-point source loads during flow peaks and mixing of baseflow and point sources during low flows. The temporal consistency of parameter estimates and thus the suitability of each approach is assessed dynamically following a new approach based on Monte-Carlo analysis. (c) 2004 Elsevier B.V. All rights reserved.

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The PhD process is uncertain, idiosyncratic and vague. Research into the management of PhDs has proved very useful for supervisors and students. It is important for everyone involved in the process to be aware of what can be done to improve the likelihood of success for PhD studies. There are many ways of tackling a PhD and it is not possible to describe construction management as a generic type of study. Rather, construction management is a source of problems and data, whereas solutions and approaches need to be based within established academic disciplines. The clear definition of a research project is an essential prerequisite for success. Although PhDs are difficult, there are many things that can be done by departments, supervisors and students to ease the difficulties. In the long run, the development of an active and dynamic research community is dependent upon a steady flow of high quality PhDs. No-one benefits from an uncompleted or failed PhD.

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Patterns of communication and behaviour emerge within a construction project in response to a construction crisis. This paper investigates, within a grounded theory framework, the nature of these patterns, the sociological and psychological forces which shape them and their relationship with crisis management efficiency. A grounded theory is presented in four parts. The first part conceives a construction crisis as a period of social instability, arising from conflicting interest groups, seeking to exercise power in the pursuit of social structures which suit their political and economic interests. The second part sees a construction crisis as a de-sensitizing phenomenon which results in a period of behavioural instability and conflict which is self-perpetuating. The third part cites social structure as an important influence upon construction crisis management efficiency, in determining the efficiency of information flow, and the level of uncertainty between those affected. The fourth part points to the in-built defence mechanisms which construction crises have and to three managerial ironies which make construction crisis management difficult.