Laminar flow in three-dimensional square-square expansions

In this work we investigate the three-dimensional laminar flow of Newtonian and viscoelastic fluids through square–square expansions. The experimental results obtained in this simple geometry provide useful data for benchmarking purposes in complex three-dimensional flows. Visualizations of the flow patterns were performed using streak photography, the velocity field of the flow was measured in detail using particle image velocimetry and additionally, pressure drop measurements were carried out. The Newtonian fluid flow was investigated for the expansion ratios of 1:2.4, 1:4 and 1:8 and the experimental results were compared with numerical predictions. For all expansion ratios studied, a corner vortex is observed downstream of the expansion and an increase of the flow inertia leads to an enhancement of the vortex size. Good agreement is found between experimental and numerical results. The flow of the two non-Newtonian fluids was investigated experimentally for expansion ratios of 1:2.4, 1:4, 1:8 and 1:12, and compared with numerical simulations using the Oldroyd-B, FENE-MCR and sPTT constitutive equations. For both the Boger and shear-thinning viscoelastic fluids, a corner vortex appears downstream of the expansion, which decreases in size and strength when the elasticity of the flow is increased. For all fluids and expansion ratios studied, the recirculations that are formed downstream of the square–square expansion exhibit a three-dimensional structure evidenced by a helical flow, which is also predicted in the numerical simulations

Three-dimensional flow of Newtonian and Boger fluids in square-square contractions

The flow of a Newtonian fluid and a Boger fluid through sudden square–square contractions was investigated experimentally aiming to characterize the flow and provide quantitative data for benchmarking in a complex three-dimensional flow. Visualizations of the flow patterns were undertaken using streakline photography, detailed velocity field measurementswere conducted using particle image velocimetry (PIV) and pressure drop measurements were performed in various geometries with different contraction ratios. For the Newtonian fluid, the experimental results are compared with numerical simulations performed using a finite volume method, and excellent agreement is found for the range of Reynolds number tested (Re2 ≤23). For the viscoelastic case, recirculations are still present upstream of the contraction but we also observe other complex flow patterns that are dependent on contraction ratio (CR) and Deborah number (De2) for the range of conditions studied: CR = 2.4, 4, 8, 12 and De2 ≤150. For low contraction ratios strong divergent flow is observed upstream of the contraction, whereas for high contraction ratios there is no upstream divergent flow, except in the vicinity of the re-entrant corner where a localized a typical divergent flow is observed. For all contraction ratios studied, at sufficiently high Deborah numbers, strong elastic vortex enhancement upstream of the contraction is observed, which leads to the onset of a periodic complex flow at higher flow rates. The vortices observed under steady flow are not closed, and fluid elasticity was found to modify the flow direction within the recirculations as compared to that found for Newtonian fluids. The entry pressure drop, quantified using a Couette correction, was found to increase with the Deborah number for the higher contraction ratios

ShakeMap: Combinação de observações instrumentais e macrossísmicas

Since 2008, the Portuguese seismological service, has implemented the ShakeMap software package provided by U.S. Geological Survey (USGS), in order to obtain reliable maps of peak ground motion parameters and seismic intensities for mainland Portugal. These maps identify the area affected by the earthquake and estimate the severity of ground shaking, thus providing important information for emergency response planning and for the general public. The maps are produced based on regional constraints from instrumental ground motions and site amplifications. In late 2009, USGS released a new version (V3.5) of ShakeMap software with added features. The new approach introduces several changes in the existing ShakeMap methodology, allowing the combination of direct observations (observed peak ground motion and seismic intensities), observations converted parameters and estimates. Some results are presented and discussed in this work

Sex and Exercise Intensity Do Not Influence Oxygen Uptake Kinetics in Submaximal Swimming.

The aim of this study was to compare the oxygen uptake ([Formula: see text]) kinetics in front crawl between male and female swimmers at moderate and heavy intensity. We hypothesized that the time constant for the primary phase [Formula: see text] kinetics was faster in men than in women, for both intensities. Nineteen well trained swimmers (8 females mean ± SD; age 17.9 ± 3.5 years; mass 55.2 ± 3.6 kg; height 1.66 ± 0.05 m and 11 male 21.9 ± 2.8 years; 78.2 ± 11.1 kg; 1.81 ± 0.08 m) performed a discontinuous maximal incremental test and two 600-m square wave transitions for both moderate and heavy intensities to determine the [Formula: see text] kinetics parameters using mono- and bi-exponential models, respectively. All the tests involved breath-by-breath analysis of front crawl swimming using a swimming snorkel. The maximal oxygen uptake [Formula: see text] was higher in men than in women [4,492 ± 585 ml·min(-1) and 57.7 ± 4.4 ml·kg(-1)·min(-1) vs. 2,752.4 ± 187.9 ml·min(-1) (p ≤ 0.001) and 50.0 ± 5.7 ml·kg(-1)·min(-1)(p = 0.007), respectively]. Similarly, the absolute amplitude of the primary component was higher in men for both intensities (moderate: 1,736 ± 164 vs. 1,121 ± 149 ml·min(-1); heavy: 2,948 ± 227 vs. 1,927 ± 243 ml·min(-1), p ≤ 0.001, for males and females, respectively). However, the time constant of the primary component (τp) was not influenced by sex (p = 0.527) or swimming intensity (p = 0.804) (moderate: 15.1 ± 5.6 vs. 14.4 ± 5.1 s; heavy: 13.5 ± 3.3 vs. 16.0 ± 4.5 s, for females and males, respectively). The slow component in the heavy domain was not significantly different between female and male swimmers (3.2 ± 2.4 vs. 3.8 ± 1.0 ml·kg(-1)·min(-1), p = 0.476). Overall, only the absolute amplitude of the primary component was higher in men, while the other [Formula: see text] kinetics parameters were similar between female and male swimmers at both moderate and heavy intensities. The mechanisms underlying these similarities remain unclear

Multicriteria power engineering problems and fuzzy set based methods of their solution

The results of research into the use of models and methods of multicriteria decision making in a fuzzy environment for solving power engineering problems are presented. Two general classes of models related to multiobjective ( models) and multiattribute ( models) problems as well as methods of their analysis based on the application of the Bellman-Zadeh approach to decision making in a fuzzy environment and techniques of fuzzy preference modeling, respectively, are briefly considered. A review of the authors’ results associated with the application of these models and methods for solving diverse types of problems of power system and subsystems planning, operation, and control is presented. The recent results on the use of and models and methods of their analysis for the allocation of reactive power sources in distribution systems and for the prioritization in maintenance planning in distribution systems, respectively, are considered.Наведено результати щодо досліджень використання моделей та методів багатокритеріального прийняття рішень в нечіткому середовищі при розв'язанні задач електроенергетичного спрямування. Розглянуто два класи моделей, які належать до багатоцільових ( модель) та багатоатрибутних ( модель) задач, а також методи їхнього аналізу, що засновані як на використанні підхода Беллмана-Заде до прийняття рішень у нечіткому середовищі, так і на техніці, пов'язаній з визначенням нечітких переваг. Представлено огляд результатів, які отримано авторами при використанні вказаних моделей та методів для вирішення задач проектування та управління роботою енергетичних систем і підсистем. Останні результати, пов'язані з використанням і моделей та методів їхнього аналізу, належать до задач роз- поділу джерел реактивної потужності у розподільних мережах та визначення пріоритетів при плануванні їхнього обслуговування.Представлены результаты исследований по использованию моделей и методов многокритериального принятия решений в нечеткой среде при решении задач электроэнергетического характера. При этом рассматривается два класса моделей, относящихся к многоцелевым (модель) и многоатрибутным (модель) задачам, а также методы их анализа, основанные как на использовании подхода Беллмана-Заде к принятию решений в нечеткой среде, так и технике, связанной с определением нечетких предпочтений. Представлен обзор результатов, полученных авторами при использовании указанных моделей и методов для решения различных задач, связанных с проектированием и управлением работой энергетических систем и подсистем. Последние результаты, связанные с применением и моделей и методов их анализа, относятся к задачам распределения источников реактивной мощности в распределительных сетях и определения приоритетов при планировании их обслуживания

Overexpression of adenosine A2A receptors in rats: effects on depression, locomotion, and anxiety

Adenosine A2A receptors (A2AR) are a sub-type of receptors enriched in basal ganglia, activated by the neuromodulator adenosine, which interact with dopamine D2 receptors. Although this reciprocal antagonistic interaction is well-established in motor function, the outcome in dopamine-related behaviors remains uncertain, in particular in depression and anxiety. We have demonstrated an upsurge of A2AR associated to aging and chronic stress. Furthermore, Alzheimer's disease patients present A2AR accumulation in cortical areas together with depressive signs. We now tested the impact of overexpressing A2AR in forebrain neurons on dopamine-related behavior, namely depression. Adult male rats overexpressing human A2AR under the control of CaMKII promoter [Tg(CaMKII-hA2AR)] and aged-matched wild-types (WT) of the same strain (Sprague-Dawley) were studied. The forced swimming test (FST), sucrose preference test (SPT), and the open-field test (OFT) were performed to evaluate behavioral despair, anhedonia, locomotion, and anxiety. Tg(CaMKII-hA2AR) animals spent more time floating and less time swimming in the FST and presented a decreased sucrose preference at 48 h in the SPT. They also covered higher distances in the OFT and spent more time in the central zone than the WT. The results indicate that Tg(CaMKII-hA2AR) rats exhibit depressive-like behavior, hyperlocomotion, and altered exploratory behavior. This A2AR overexpression may explain the depressive signs found in aging, chronic stress, and Alzheimer's disease

Population overlap and habitat segregation in wintering Black-tailed Godwits Limosa limosa

Distinct breeding populations of migratory species may overlap both spatially and temporally, but differ in patterns of habitat use. This has important implications for population monitoring and conservation. To quantify the extent to which two distinct breeding populations of a migratory shorebird, the Black-tailed Godwit Limosa limosa, overlap spatially, temporally and in their use of different habitats during winter. We use mid-winter counts between 1990 and 2001 to identify the most important sites in Iberia for Black-tailed Godwits. Monthly surveys of estuarine mudflats and rice-fields at one major site, the Tejo estuary in Portugal in 2005-2007, together with detailed tracking of colour-ringed individuals, are used to explore patterns of habitat use and segregation of the Icelandic subspecies L. l. islandica and the nominate continental subspecies L. l. limosa. In the period 1990-2001, over 66 000 Black-tailed Godwits were counted on average in Iberia during mid-winter (January), of which 80% occurred at just four sites: Tejo and Sado lower basins in Portugal, and Coto Dontildeana and Ebro Delta in Spain. Icelandic Black-tailed Godwits are present throughout the winter and forage primarily in estuarine habitats. Continental Black-tailed Godwits are present from December to March and primarily use rice-fields. Iberia supports about 30% of the Icelandic population in winter and most of the continental population during spring passage. While the Icelandic population is currently increasing, the continental population is declining rapidly. Although the estuarine habitats used by Icelandic godwits are largely protected as Natura 2000 sites, the habitat segregation means that conservation actions for the decreasing numbers of continental godwits should focus on protection of rice-fields and re-establishment of freshwater wetlands

Fibulin-4 deficiency differentially affects cytoskeleton structure and dynamics as well as TGF beta signaling

Fibulin-4 is an extracellular matrix (ECM) protein essential for elastogenesis and mutations in this