691 research outputs found

    Ultrasound imaging of tumor perfusion

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    Impact of culture towards disaster risk reduction

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    Number of natural disasters has risen sharply worldwide making the risk of disasters a global concern. These disasters have created significant losses and damages to humans, economy and society. Despite the losses and damages created by disasters, some individuals and communities do not attached much significance to natural disasters. Risk perception towards a disaster not only depends on the danger it could create but also the behaviour of the communities and individuals that is governed by their culture. Within this context, this study examines the relationship between culture and disaster risk reduction (DRR). A comprehensive literature review is used for the study to evaluate culture, its components and to analyse a series of case studies related to disaster risk. It was evident from the study that in some situations, culture has become a factor for the survival of the communities from disasters where as in some situations culture has acted as a barrier for effective DRR activities. The study suggests community based DRR activities as a mechanism to integrate with culture to effectively manage disaster risk

    Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket

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    [EN] The prediction of the pressure inside the air pocket in water pipelines has been the topic for a lot of research works. Several aspects in this field have been discussed, such as the filling and the emptying procedures. The emptying process can affect the safety and the efficiency of water systems. Current research presents an analysis of the emptying process using experimental and computational results. The phenomenon is simulated using the two-dimensional computational fluid dynamics (2D CFD) and the one-dimensional mathematical (1D) models. A backflow air analysis is also provided based on CFD simulations. The developed models show good ability in the prediction of the sub-atmospheric pressure and the flow velocity in the system. In most of the cases, the 1D and 2D CFD models show similar performance in the prediction of the pressure and the velocity results. The backflow air development can be accurately explained using the CFD model.This work was supported by the Fundação para a Ciência e a Tecnologia (FCT), Portugal under grant number PD/BD/114459/2016.Besharat, M.; Coronado-Hernández, OE.; Fuertes-Miquel, VS.; Viseu, MT.; Ramos, HM. (2018). Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket. Urban Water Journal. 15(8):769-779. https://doi.org/10.1080/1573062X.2018.1540711S769779158Benjamin, T. B. (1968). Gravity currents and related phenomena. Journal of Fluid Mechanics, 31(2), 209-248. doi:10.1017/s0022112068000133Besharat, M., Teresa Viseu, M., & Ramos, H. (2017). Experimental Study of Air Vessel Behavior for Energy Storage or System Protection in Water Hammer Events. Water, 9(1), 63. doi:10.3390/w9010063Besharat, M., Tarinejad, R., & Ramos, H. M. (2015). The effect of water hammer on a confined air pocket towards flow energy storage system. Journal of Water Supply: Research and Technology-Aqua, 65(2), 116-126. doi:10.2166/aqua.2015.081Besharat, M., Tarinejad, R., Aalami, M. T., & Ramos, H. M. (2016). Study of a Compressed Air Vessel for Controlling the Pressure Surge in Water Networks: CFD and Experimental Analysis. Water Resources Management, 30(8), 2687-2702. doi:10.1007/s11269-016-1310-1Coronado-Hernández, O., Fuertes-Miquel, V., Besharat, M., & Ramos, H. (2017). Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water, 9(2), 98. doi:10.3390/w9020098Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Besharat, M., & Ramos, H. M. (2018). Subatmospheric pressure in a water draining pipeline with an air pocket. Urban Water Journal, 15(4), 346-352. doi:10.1080/1573062x.2018.1475578Edmunds, R. C. (1979). Air Binding in Pipes. Journal - American Water Works Association, 71(5), 272-277. doi:10.1002/j.1551-8833.1979.tb04348.xEscarameia, M. (2007). Investigating hydraulic removal of air from water pipelines. Proceedings of the Institution of Civil Engineers - Water Management, 160(1), 25-34. doi:10.1680/wama.2007.160.1.25Izquierdo, J., Fuertes, V. S., Cabrera, E., Iglesias, P. L., & Garcia-Serra, J. (1999). Pipeline start-up with entrapped air. Journal of Hydraulic Research, 37(5), 579-590. doi:10.1080/00221689909498518Kader, B. A. (1981). Temperature and concentration profiles in fully turbulent boundary layers. International Journal of Heat and Mass Transfer, 24(9), 1541-1544. doi:10.1016/0017-9310(81)90220-9Laanearu, J., Annus, I., Koppel, T., Bergant, A., Vučković, S., Hou, Q., … van’t Westende, J. M. C. (2012). Emptying of Large-Scale Pipeline by Pressurized Air. Journal of Hydraulic Engineering, 138(12), 1090-1100. doi:10.1061/(asce)hy.1943-7900.0000631Leon, A. S., Ghidaoui, M. S., Schmidt, A. R., & Garcia, M. H. (2010). A robust two-equation model for transient-mixed flows. Journal of Hydraulic Research, 48(1), 44-56. doi:10.1080/00221680903565911Martins, N. M. C., Delgado, J. N., Ramos, H. M., & Covas, D. I. C. (2017). Maximum transient pressures in a rapidly filling pipeline with entrapped air using a CFD model. Journal of Hydraulic Research, 55(4), 506-519. doi:10.1080/00221686.2016.1275046Martins, S. C., Ramos, H. M., & Almeida, A. B. (2015). Conceptual analogy for modelling entrapped air action in hydraulic systems. Journal of Hydraulic Research, 53(5), 678-686. doi:10.1080/00221686.2015.1077353Pozos, O., Gonzalez, C. A., Giesecke, J., Marx, W., & Rodal, E. A. (2010). Air entrapped in gravity pipeline systems. Journal of Hydraulic Research, 48(3), 338-347. doi:10.1080/00221686.2010.481839Ramezani, L., Karney, B., & Malekpour, A. (2016). Encouraging Effective Air Management in Water Pipelines: A Critical Review. Journal of Water Resources Planning and Management, 142(12), 04016055. doi:10.1061/(asce)wr.1943-5452.0000695Richards, R. T. (1962). Air Binding in Water Pipelines. Journal - American Water Works Association, 54(6), 719-730. doi:10.1002/j.1551-8833.1962.tb00883.xTijsseling, A. S., Hou, Q., Bozkuş, Z., & Laanearu, J. (2015). Improved One-Dimensional Models for Rapid Emptying and Filling of Pipelines. Journal of Pressure Vessel Technology, 138(3). doi:10.1115/1.4031508Triki, A. (2015). Water-hammer control in pressurized-pipe flow using an in-line polymeric short-section. Acta Mechanica, 227(3), 777-793. doi:10.1007/s00707-015-1493-1Vasconcelos, J. G., & Wright, S. J. (2008). Rapid Flow Startup in Filled Horizontal Pipelines. Journal of Hydraulic Engineering, 134(7), 984-992. doi:10.1061/(asce)0733-9429(2008)134:7(984)Wang, H., Zhou, L., Liu, D., Karney, B., Wang, P., Xia, L., … Xu, C. (2016). CFD Approach for Column Separation in Water Pipelines. Journal of Hydraulic Engineering, 142(10), 04016036. doi:10.1061/(asce)hy.1943-7900.0001171Zhou, F., Hicks, F. E., & Steffler, P. M. (2002). Transient Flow in a Rapidly Filling Horizontal Pipe Containing Trapped Air. Journal of Hydraulic Engineering, 128(6), 625-634. doi:10.1061/(asce)0733-9429(2002)128:6(625)Zhou, L., Liu, D., & Karney, B. (2013). Investigation of Hydraulic Transients of Two Entrapped Air Pockets in a Water Pipeline. Journal of Hydraulic Engineering, 139(9), 949-959. doi:10.1061/(asce)hy.1943-7900.0000750Zhou, L., Liu, D., & Ou, C. (2011). Simulation of Flow Transients in a Water Filling Pipe Containing Entrapped Air Pocket with VOF Model. Engineering Applications of Computational Fluid Mechanics, 5(1), 127-140. doi:10.1080/19942060.2011.11015357Zhou, L., Wang, H., Karney, B., Liu, D., Wang, P., & Guo, S. (2018). Dynamic Behavior of Entrapped Air Pocket in a Water Filling Pipeline. Journal of Hydraulic Engineering, 144(8), 04018045. doi:10.1061/(asce)hy.1943-7900.0001491Zukoski, E. E. (1966). Influence of viscosity, surface tension, and inclination angle on motion of long bubbles in closed tubes. Journal of Fluid Mechanics, 25(4), 821-837. doi:10.1017/s002211206600044

    Pattern and Outcome of Chest Injuries at Bugando Medical Centre in Northwestern Tanzania.

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    Chest injuries constitute a continuing challenge to the trauma or general surgeon practicing in developing countries. This study was conducted to outline the etiological spectrum, injury patterns and short term outcome of these injuries in our setting. This was a prospective study involving chest injury patients admitted to Bugando Medical Centre over a six-month period from November 2009 to April 2010 inclusive. A total of 150 chest injury patients were studied. Males outnumbered females by a ratio of 3.8:1. Their ages ranged from 1 to 80 years (mean = 32.17 years). The majority of patients (72.7%) sustained blunt injuries. Road traffic crush was the most common cause of injuries affecting 50.7% of patients. Chest wall wounds, hemothorax and rib fractures were the most common type of injuries accounting for 30.0%, 21.3% and 20.7% respectively. Associated injuries were noted in 56.0% of patients and head/neck (33.3%) and musculoskeletal regions (26.7%) were commonly affected. The majority of patients (55.3%) were treated successfully with non-operative approach. Underwater seal drainage was performed in 39 patients (19.3%). One patient (0.7%) underwent thoracotomy due to hemopericardium. Thirty nine patients (26.0%) had complications of which wound sepsis (14.7%) and complications of long bone fractures (12.0%) were the most common complications. The mean LOS was 13.17 days and mortality rate was 3.3%. Using multivariate logistic regression analysis, associated injuries, the type of injury, trauma scores (ISS, RTS and PTS) were found to be significant predictors of the LOS (P < 0.001), whereas mortality was significantly associated with pre-morbid illness, associated injuries, trauma scores (ISS, RTS and PTS), the need for ICU admission and the presence of complications (P < 0.001). Chest injuries resulting from RTCs remain a major public health problem in this part of Tanzania. Urgent preventive measures targeting at reducing the occurrence of RTCs is necessary to reduce the incidence of chest injuries in this region

    La incuestionabilidad del riesgo

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    Con anterioridad a la década de 1980, la literatura especializada en análisis y gestión del riesgo estaba dominada por la llamada visión tecnocrática o dominante. Esta visión establecía que los desastres naturales eran sucesos físicos extremos, producidos por una naturaleza caprichosa, externos a lo social y que requerían soluciones tecnológicas y de gestión por parte de expertos. Este artículo se centra en desarrollar una nueva explicación para entender la persistencia hegemónica de la visión tecnocrática basada en el concepto de incuestionabilidad del riesgo. Esta propuesta conceptual hace referencia a la incapacidad y desidia de los expertos, científicos y tomadores de decisiones en general (claimmakers) de identificar y actuar sobre las causas profundas de la producción del riesgo ya que ello conllevaría a cuestionar los imperativos normativos, las necesidades de las elites y los estilos de vida del actual sistema socioeconómico globalizado.Before de 1980s, the natural hazard analysis and management specialized literature was dominated by the so called "dominant" or "technocratic" view. Such perspective had established that natural disasters are extreme physical events caused by a whimsical nature and that these events are external to society. These events required technological and management solutions developed by experts. The current article aims at addressing a new explanatory component in the hegemonic persistence of the technocratic view. Such assumption was based on the "unquestionability of the risk" concept. It is stated that the "unquestionability of the risk" is the overall incapacity and neglect of experts, scientists and decision makers to identify and act over the deep causes of risk production, since it would make them question the normative imperatives and the demands from the elite as well as the life style in nowadays globalized socio-economic system

    Masonry dams : analysis of the historical profiles of Sazilly, Delocre and Rankine

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    The significant advances in masonry dam design that took place in the second half of the 19th century are analyzed and discussed within the context of the historical development of dam construction. Particular reference is made to the gravity dam profiles proposed by Sazilly, Delocre and Rankine, who pioneered the application of engineering concepts to dam design, basing the dam profile on the allowable stresses for the conditions of empty and full reservoir. These historical profiles are analyzed taking into consideration the present safety assessment procedures, by means of a numerical application developed for this purpose, based on limit analysis equilibrium methods, which considers the sliding failure mechanisms, the most critical for these structures. The study underlines the key role of uplift pressures, which was only addressed by Lévy after the accident of Bouzey dam, and provides a critical understanding of the original design concepts, which is essential for the rehabilitation of these historical structures.This work has been funded by FCT (Portuguese Foundation for Science and Technology) through the PhD grant SFRH/BD/43585/2008, for which the first author is grateful

    The impact of education, country, race and ethnicity on the self-report of postpartum depression using the Edinburgh Postnatal Depression Scale

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    Universal screening for postpartum depression is recommended in many countries. Knowledge of whether the disclosure of depressive symptoms in the postpartum period differs across cultures could improve detection and provide new insights into the pathogenesis. Moreover, it is a necessary step to evaluate the universal use of screening instruments in research and clinical practice. In the current study we sought to assess whether the Edinburgh Postnatal Depression Scale (EPDS), the most widely used screening tool for postpartum depression, measures the same underlying construct across cultural groups in a large international dataset. Ordinal regression and measurement invariance were used to explore the association between culture, operationalized as education, ethnicity/race and continent, and endorsement of depressive symptoms using the EPDS on 8209 new mothers from Europe and the USA. Education, but not ethnicity/race, influenced the reporting of postpartum depression [difference between robust comparative fit indexes (∆*CFI) 0.01), but not between European countries (∆*CFI < 0.01). Investigators and clinicians should be aware of the potential differences in expression of phenotype of postpartum depression that women of different educational backgrounds may manifest. The increasing cultural heterogeneity of societies together with the tendency towards globalization requires a culturally sensitive approach to patients, research and policies, that takes into account, beyond rhetoric, the context of a person's experiences and the context in which the research is conducted
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