Heat to electricity thermoacoustic-magnetohydrodynamic conversion

In this work, a new concept for the conversion of heat into electricity is presented. The conversion is based on the combined effects of a thermoacoustic prime mover coupled with a magnetohydrodynamic generator, using different working fluids in each process. The results of preliminary experiments are also presented.Comment: Short article, 5 figures, 5 page

Reynolds number and Shallow Depth Sloshing

The dependence on the Reynolds number of shallow depth sloshing flows inside rectangular tanks subjected to forced harmonic motion is studied in this paper with weakly compressible SPH. We are interested in assessing the in fluenceof viscous effects on the dynamics of shallow depth sloshing flows by using an SPH solver and by comparing with a Navier-Stokes level-set solver results. The goal of trying to model these viscous flows is compromised by the resolution requested due to their Reynolds number, if boundary layer effects are to be modeled. The convenience and feasibility of the implementation of free-slip and no-slip boundary conditions is also discusse

HMAP Dataset 12: North-west Scotland Fisheries

Catch data, herring, haddock, Norway lobster, 1893-2005, West Scotland, 1893-2005. The map below gives an indication of the extent of the Celtic-Biscay Shelf; the 'view as map' link in the download panel at the right will show a much more detailed representation. The kml file download, when used with Google Earth, will render the extent of the Celtic-Biscay Shelf in detail

The self-stimulated capillary jet

Inspired by a Savart’s pioneering work, we study the self-stimulated dynamics of a capillary jet. The feedback loop is realised by extracting surface perturbations from a section of the jet itself via a laser–photodiode pair, whose amplified signal drives an electromechanical actuator which, in turn, produces pressure perturbations at the exit chamber. Under specific conditions, this loop establishes phase-locked stimulation regimes that overcome the otherwise random natural breakup. For each laser position along the jet, the gain of the amplifier acts as a selector across a discrete set of observable frequencies. The main observed features are explained by a linear theory which combines the transfer function of each stage in the loop. Our findings are relevant to continuous inkjet technologies for the production of equally sized droplets

Inversión de los patrones estacionales de la absorción de carbono en un stand de eucalipto en Portugal

This paper summarizes results between 2002 and 2010 from eddy covariance measurements of carbon uptake in the 12 month annual growing period eucalypt site of Espirra in Southern Portugal (38° 38’N, 8° 36’ W) . This site, aimed for pulp production is part of an intensively 300 ha eucalypt coppice, with about 1100 trees ha–1. The climate is of Mediterranean type. During the measurement period (2002-2010) two main events changed the annual sink pattern of the forest: a drought period of two years (2004-2005) and a tree felling (November and December 2006). Before the felling, annual net ecosystem exchange (NEE) diminished from 865.56 gCm–2 in 2002 to 356.64 gCm–2 in 2005 together with a deep decrease in rainfall from 748 mm in 2002 to 378.58 mm and 396.64 mm in 2004 and 2005, respectively. The eucalypt stand recovered its carbon sink ability in June 2007 with a cumulated NEE of 151 gCm–2 from January to September 2010. A quantitative approach using generalized estimating equations (GEEs) was made to relate monthly NEE, gross primary production (GPP) and soil moisture with the main meteorological variables. Seasonal patterns of carbon uptake were almost opposite in the periods before and after the felling with maxima in April and August, respectively, and this seasonal change is gradually reversing to the pattern before 2006. Drought was the main meteorological driver of these temporal tendencies in carbon uptake.Este documento resume los resultados entre 2002 y 2010 a partir de mediciones de covarianza turbulenta de la absorción de carbono en los 12 meses anuales a los sitios de crecimiento de eucalipto período de Espirra en el sur de Portugal (38° 38’N, 8° 36’ W). Este sitio, con el objetivo para la producción de celulosa es parte de un monte bajo de intensidad 300 hectáreas de eucaliptos, con cerca de 1.100 árboles ha–1. El clima es de tipo mediterráneo. Durante el período de medición (2002-2010) dos eventos principales cambiado el patrón fregadero anual de la selva: un período de sequía de dos años (2004-2005) y la tala de árboles (noviembre y diciembre de 2006). Antes de la tala, el intercambio anual neta de los ecosistemas (NEE) se redujo de 865,56 g cm–2 en 2002 a 356,64 g cm–2 en 2005, junto con una disminución profunda de las precipitaciones de 748 mm en 2002 a 378,58 mm y 396,64 en 2004 y 2005, respectivamente. El eucalipto de pie recupera su capacidad de sumidero de carbono en junio de 2007 con un acumulado de 151 gcm NEE–2 de enero a septiembre de 2010.Una aproximación cuantitativa mediante ecuaciones de estimación generalizada (GEES) se hizo para relacionar mensual NEE, la producción primaria bruta (GPP) y la humedad del suelo con las variables meteorológicas principales.Los patrones estacionales de la absorción de carbono eran casi opuestas en los períodos antes y después de la tala, con máximos en abril y agosto, respectivamente, y este cambio de temporada se va de marcha atrás para el patrón antes de 2006. La sequía fue el principal impulsor de estas tendencias meteorológicas temporal en la absorción de carbono

Reversing of seasonal patterns of carbon uptake in an eucalyptus stand in Portugal after drought and felling

This paper summarizes results between 2002 and 2010 from eddy covariance measurements of carbon uptake in the 12 month annual growing period eucalypt site of Espirra in Southern Portugal (38° 38’N, 8° 36’ W) . This site, aimed for pulp production is part of an intensively 300 ha eucalypt coppice, with about 1100 trees ha–1. The climate is of Mediterranean type. During the measurement period (2002-2010) two main events changed the annual sink pattern of the forest: a drought period of two years (2004-2005) and a tree felling (November and December 2006). Before the felling, annual net ecosystem exchange (NEE) diminished from 865.56 gCm–2 in 2002 to 356.64 gCm–2 in 2005 together with a deep decrease in rainfall from 748 mm in 2002 to 378.58 mm and 396.64 mm in 2004 and 2005, respectively. The eucalypt stand recovered its carbon sink ability in June 2007 with a cumulated NEE of 151 gCm–2 from January to September 2010. A quantitative approach using generalized estimating equations (GEEs) was made to relate monthly NEE, gross primary production (GPP) and soil moisture with the main meteorological variables. Seasonal patterns of carbon uptake were almost opposite in the periods before and after the felling with maxima in April and August, respectively, and this seasonal change is gradually reversing to the pattern before 2006. Drought was the main meteorological driver of these temporal tendencies in carbon uptake

On Hirschman and log-Sobolev inequalities in mu-deformed Segal-Bargmann analysis

We consider a deformation of Segal-Bargmann space and its transform. We study L^p properties of this transform and obtain entropy-entropy inequalities (Hirschman) and entropy-energy inequalities (log-Sobolev) that generalize the corresponding known results in the undeformed theory.Comment: 42 pages, 3 figure

First report and preliminary evaluation of cassava root necrosis in Angola

Open Access ArticleCassava is a main staple food for 800 million people world-wide. Production is limited by pest and pathogens. The most devastating cassava viruses are Cassava Brown Streak Virus and Uganda Cassava Brown Streak Virusboth causing severe root necrosis called Cassava Brown Streak Disease. In the last 10 years, the Cassava Brown Streak Disease (CBSD)has spread across Africa from the east coast of Africa to central Africa. Similar root necrosis to cassava brown streak disease has also been identified in the Democratic Republic of Congo where the first symptoms were identified in 2002 in Kinshasa and Kongo central province. In 2012, the presence of CBSD was confirmed in eastern Democratic Republic of Congo. All attempts since 2002 in western Democratic Republic of Congo to identify the cause of these root necrosis have failed. In 2017, a team of scientists surveying the Songololo Territory in the Kongo central province at the northern Angola, identified the same root necrosis similar to CBSD in several localities bordering Angola. These unexpected results will foreshadow the presence of cassava root necrosis in Angola. This preliminary investigation in northern Angola was conducted specifically in the Zaire province and the territory of Mbanza Kongo at approximatively 62 kms from the Democratic Republic of Congo border in order to verify, whether or not, these root necrosis are present in Angola. Results obtained from this exploratory survey in several fields of the Zaire province and territory of Mbanza Kongo confirmed, for the first time, the presence of cassava root necrosis in Angola, similar to CBSD, as identified in western DRC

Mesa redonda: La Estadística en la Investigación Médica

Este artículo es una transcripción de las conferencias dictadas en la mesa organizada en el 4º Congreso Galego de Estatistica y Investigación de Operacions que tuvo lugar en Santiago de Compostela en noviembre de 1999. Los autores discuten sobre el posible uso o abuso de la estadística en artículos científicos, sobre lo que se necesitaría para alcanzar la interdisciplinariedad y lo que se entiende por éxito profesional. Se define la disciplina (bioestadística) y se identifica a sus profesionales (bioestadísticos). Se discute sobre el papel de un bioestadístico en un equipo de investigación médico y se repasan las dificultades que tienen los médicos para realizar estudios clínico-epidemiológicos