Suchergebnisse

Un supuesto de gran parte de los estudios empíricos sobre la criminalidad es que víctimas y victimarios conviven en una misma unidad geográfica, lo cual implica utilizar los rasgos socioeconómicos del lugar de residencia del denunciante como factores determinantes del crimen. En este estudio se ofrece una mirada alternativa que consiste en medir la criminalidad sobre la base de la proporción de imputados en la población total, considerando las características de las comunas de procedencia pertinentes como causas socioeconómicas de la delincuencia. Se concluye que los imputados presentan un grado importante de movilidad espacial. En el caso de los delitos de motivación económica, las evidencias respaldan parcialmente los postulados de Becker. Por último, se muestra que el número de imputado

This paper is focused on the study of a type of drift eliminator installed in a mechanical draft cooling tower. Drift eliminators are installed in cooling towers in order to avoid water droplets to be emitted to the ambient. These droplets are formed by the crossflow between airflow and water pulverization inside the tower. The study is centered on the analysis of three aspects: the water film formed on the plates of the drift eliminator, the size of water droplets detached from this film and the flow conditions for the detachment of these droplets. These aspects are studied with a multiphase numerical approach, validated by experimental tests. Good agreement is obtained between numerical and experimental results. The study shows that the behavior of water droplets is very influenced by air velocity inside the cooling tower. Moreover, limits for air velocity are set for the drift eliminator not to act as a droplet generator itself. ; This research is sponsored by the Spanish Government, through the Projects No. ENE2013-48696-C2-2-R and ENE2013-48696-C2-1-R, including FEDER (European Union).

This research was funded by Ministerio de Ciencia, Innovacion y Universidades, grant number FPU: 19/02609, FPU: 17/00408 and FPU: 16/01531 and by University of Granada, grant number FPU: PP20/05. ; Background: Adults living with Chronic Obstructive Pulmonary Disease (COPD) often have difficulties when trying to access health care services. Interactive communication technologies are a valuable tool to enable patients to access supportive interventions to cope with their disease. The aim of this revision and meta-analysis is to analyze the content and efficacy of web-based supportive interventions in quality of life in COPD. Methods: Medline (via PubMed), Web of Science, and Scopus were the databases used to select the studies for this systematic review. A screening, analysis, and assessment of the methodological quality was carried out by two independent researchers. A meta-analysis of the extracted data was performed. Results: A total of 9 of the 3089 studies reviewed met the inclusion criteria. Most repeated web content elements were educational and involved communication with healthcare professional content. Finally, seven of the nine studies were included in a quantitative analysis. Web-based supportive interventions significantly improved quality of life when added to usual care (SMD = -1.26, 95% CI = -1.65, -0.86; p < 0.001) but no significant differences were found when compared with an autonomous pedometer walking intervention (p = 0.64) or a face-to-face treatment (p = 0.82). Conclusion: This systematic review and meta-analysis suggests that web-based supportive interventions may complement or accompany treatments in COPD patients due to the advantages of online interventions. The results obtained should be treated with caution due to the limited number of studies in this area and methodological weaknesses. ; University of Granada FPU: PP20/05 ; Spanish Government FPU: 19/02609 FPU: 17/00408 FPU: 16/01531

An experimental prototype of a mechanical draft cooling tower has been set up to study the interaction of air and water in a drift eliminators. It consists on a prismatic structure; an airstream is introduced from the bottom of the tower; and a water circuit injects water inside the tower, through one of the plates of the drift eliminator, forming a water film simulating the films formed by the atomization of water in real towers. 2D and 3D numerical models have been developed in order to simulate the behavior of air and water inside the cooling tower and compare these results with experimental data. The main objective of this work is to describe the interaction between the water film and the air flow on the plates of the drift eliminator and to determine the operating conditions for the drift eliminator to act itself as a droplet generator. This means to determine the critical values for the air flow to make water droplets, originated from the eliminator plates, to be drifted by the airstream to outside "breakthrough". ; This research is sponsored by the Spanish Government, through the Projects ENE2013-48696-C2-2-R, as well as by the Seneca-Agency for Science and Technology of the Region of Murcia (Spain), through the Project 15184/PI/10.

Adiabatic cooling pads are mostly used as a previous step for cooling systems, they cause the raise of the cooling system global efficiency. In this study, several types of pads have been analysed regarding on its compactness and thickness. The problem is addressed from an experimental, analytical and numerical point of view.vThe validation of the temperature drop and cooling efficiency of the cooling pad numerical model is the main objective of this paper, and, in order to get this goal, Discrete Phase Model (DPM) of ANSYS Fluent software is used to calculate how water droplets, injected over the pad to cool the air, evaporate and how the continuous phase affect them. The results of this paper, focused to be a part of a complete cooling system analysis carried out by the research group, show the performance of an adiabatic cooling pad varying its width and compactness. ; The authors acknowledge the financial support received from the Spanish Government, through Projects ENE2013-48696-C2-1-R and C2-2-R as well as by the FEDER (Fondo Europeo de Desarrollo Regional).

Introducing an air pre-cooler step before an air cooler system have been proved to improve the global efficiency of a cooling setup. Several authors have studied the mass and the heat exchanges of an air stream and the water sprayed inside an adiabatic cooling pad. However, these previous studies present their results and correlations as functions of experimental dependent parameters. Therefore, the aim of this study is to develop a numerical modeling capable of characterizing the behavior of an air pre-cooling stage without the need of previous experimental tests, allowing an accurate initial study when designing an air cooler installation. Several numerical models and simulation tests have been developed by our researching group in order to get a proper approximation of the problem, and the employment of previous experimental data allowed the model validation in terms of pressure drop and air cooling efficiency. As a result, a numerical model is defined, validated, and compared with existing empirical correlations models as a first step to determine the best possible cooling pad configuration in every air cooling setup as a function of the pad geometry, air and water flow rates, with an only numerical simulation. ; The authors acknowledge the financial support received from the Spanish Government, through Projects ENE2013-48696-C2-1-R and C2-2-R as well as by the FEDER (FondoEuropeo de Desarrollo Regional)