Search results for "GW"

Non-Gaussian probability density function of SDOF linear structures under wind actions

1998

Abstract Wind velocity is usually analytically described adding a static mean term to a zero mean fluctuation stationary process. The corresponding aerodynamic alongwind force acting on a single degree of freedom (SDOF) structure can be considered as a sum of three terms proportional to the mean wind velocity, to the product between mean and fluctuating part of the wind velocity and to the square power of the fluctuating wind velocity, respectively. The latter term, often neglected in the literature, is responsible for the non-Gaussian behaviour of the response. In this paper a method for the evaluation of the stationary probability density function of SDOF structures subjected to non-Gauss…

Assessment of the Potential Evapotranspiration MODIS Product Using Ground Measurements in the Pampas

2018

Evapotranspiration is the hydrological variable of greatest relevance in the Argentina Pampas Region (APR). The estimation of potential evapotranspiration (PET) in this area becomes essential since primary productivity is directly linked to water availability. In order to evaluate the MOD16_A2 product of evapotranspiration (ET), a comparison with in situ measurements was conducted. We used ET data provided by the Oficina de Riesgo Agropecuario, corresponding to 24 stations placed in the region covering all seasons for the years 2012 to 2014. Results show an overestimation of 86% and 52% in Autumn-Winter and Spring-Summer, respectively. Mean Absolut Error (MAE) range between ±0.9 and ±2.1 mm…

Time-resolving Analysis of Cryotropic Gelation of Water/Poly(Vinyl Alcohol) Solutions via Small Angle Neutron Scattering

2007

The structural transformations occurring in initially homogeneous aqueous solutions of poly(vinyl alcohol) (PVA) through application of freezing (-13 degrees C) and thawing (20 degrees C) cycles is investigated by time resolving small-angle neutron scattering (SANS). These measurements indicate that formation of gels of complex hierarchical structure arises from occurrence of different elementary processes, involving different length and time scales. The fastest process that could be detected by our measurements during the first cryotropic treatment consists of the crystallization of the solvent. However, solvent crystallization is incomplete, and an unfrozen liquid microphase more concentr…

2021

Abstract. The strong reduction of air traffic during the COVID-19 pandemic provides a unique test case for the relationship between air traffic density, contrails, and their radiative forcing of climate change. Here, air traffic and contrail cirrus changes are quantified for a European domain for March to August 2020 and compared to the same period in 2019. Traffic data show a 72 % reduction in flight distance compared with 2019. This paper investigates the induced contrail changes in a model study. The contrail model results depend on various methodological details as discussed in parameter studies. In the reference case, the reduced traffic caused a reduction in contrail length. The reduc…

Definition and predictability of an OLR based West African monsoon onset

2008

The monsoon onset is documented in terms of latitudinal shift of deep convection areas within the ITCZ using an interpolated version of the National Oceanic and Atmospheric Administration (NOAA) Outgoing Longwave Radiation (OLR) at a 5-day time-step over West Africa for the period 1979–2004. Signals in moist convection derived from OLR values lower than 180 W/m2 allow better determination of onset dates (ODs) than the use of other thresholds or of the raw values of OLR. Such ODs are defined without any time filtering or spatial averaging along the meridional plane. They are also significantly correlated with ODs based on other datasets such as the CMAP and Global Precipitation Climatology P…

Genetically elevated gamma-glutamyltransferase and Alzheimer's disease

2018

Observational epidemiological evidence supports a linear and independent association between serum gamma-glutamyltransferase (GGT) concentrations and the risk of Alzheimer's disease (AD). However, the causality of this association has not been previously investigated. We sought to assess the causal nature of this association using a Mendelian randomization (MR) approach. Using inverse-variance weighted MR analysis, we assessed the association between GGT and AD using summary statistics for single nucleotide polymorphism (SNP)-AD associations obtained from the International Genomics of Alzheimer's Project of 17,008 individuals with AD and 37,154 controls. We used 26 SNPs significantly associ…

Słownik gwar śląskich

2016

Słownik gwar Śląskich [Dictionary of Silesian Dialects] contains vocabulary from all of the region’s dialects. The dictionary is based on rich lexical materiał, which has been collected sińce the 1950s. The first volume was published in 2000, sińce then thirteen volumes have appeared (containing vocabulary starting with letters from A to J). The core of the materiał is constituted by 20th-eentury vocabulary; however, there are many components of older origin. The aim of the editorial board is the archiving of the Silesian glossary and the structure of the dictionary is subordinated to this purpose. The article presents the structure of the entries, the rules of semantic description of the l…

High-pressure crystal structure investigation of synthetic Fe2SiO4 spinel.

2011

AbstractThe crystal structure of Fe2SiO4 spinel at room temperature was investigated at seven different pressures by X-ray diffraction, using a diamond anvil cell to examine the influence of Fe substitution on ringwoodite behaviour at high pressure. The results compared with those of a pure Mg endmember show that the substitution of Fe into the spinel structure causes only small changes in the compression rate of coordination polyhedra and the distortion of the octahedron. The data show that the compression rate for the octahedron and tetrahedron in (Mg,Fe)2SiO4 can be considered statistically equal for FeO6 and MgO6, as well as for SiO4 in both the endmembers. This shows why almost identic…

Genetics of exceptional longevity: possible role of GM allotypes

2018

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Zvaigžņotā Debess: 2017/18, Ziema (238)

2017

Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: I.Vilka. Starry Sky and Birds’ Journeys (abridged) ; N.Cimahoviča. Spirals of Saturn’s Rings (abridged) ; I.Šmelds. V Readings of Friedrich Zander ; DEVELOPMENTS in SCIENCE: K.Schwartz. Most Distant Galaxy Clusters and 3D Structure of the Universe ; DISCOVERIES: M.Gills. The Day when Multi-Messenger Astronomy Was Announced ; I.Pundure. ESO Telescopes and Hubble Observe the Source of Gravitational Waves for the First Time ; I.Eglītis. Asteroid “Balklavs” ; SPACE RESEARCH and EXPLORATION: R.Misa. Mission of Cassini – Discoveries to the Very End ; J.Jaunbergs. The Icy World Tethys ; OBSERVATORIES and INSTRUMENTS: M.Gills. The Giant Radio Telescope…