Search results for "Planetary Science"

Maria Mulet, escriptora i docent (1911-1982)

2020

Resum: Els estudis sobre les contribucions de les escriptores valencians de la postguerrasón més aviat escassos, però a poc a poc s’avança en aquesta matèria. En el present treballtractem de poesia escrita per dones al llarg de la postguerra i, concretament, començareml’estudi de l’obra de Maria Mulet, nascuda el 1911 i que va ser una de les dones silenciadesque van experimentar un canvi social després de la guerra i que en van patir les conseqüències.Mestra i escriptora que sabia molt bé aprofitar tots els recursos que havia de subministrarper a escriure i treballar, va escriure en valencià i en castellà, a més de ser creadora de lecturesper a utilitzar-les a l’aula, en un moment en què l…

Identifying sensitive windows of exposure to NO2 and fetal growth trajectories in a Spanish population-based birth cohort

2020

Measuring agglomeration by spatial effects: a proposal

2015

In this paper we examine the influence of spatial dependence on the estimation of the effect of standard measures of agglomeration on local growth. The hypothesis is that the forces of agglomeration do not use up their effects inside a single local area but extend to wider geographic areas, particularly on the adjacent territories. To account for these spatial effects, we propose a modification of the traditional agglomeration index, suggested by Maurel and Sedillot (1999), including both agglomeration of economic activity within an area and neighbour effects, that is, the effect of agglomeration that comes from neighbouring areas. In the empirical exercise we compute the a-spatial and the …

Management, planning and protection of terraced hillsides in the Region of Valencia

2010

14 páginas, 6 figuras, 2 tablas.

Proximal-sensing-powered modelling of energy-water fluxes in a vineyard: A spatial resolution analysis

2021

Spatial resolution is a key parameter in energy–water surface flux modelling. In this research, scale effects are analyzed on fluxes modelled with the FEST-EWB model, by upscaling both its inputs and outputs separately. The main questions are: (a) if high-resolution remote sensing images are necessary to accurately model a heterogeneous area; and (b) whether and to what extent low-resolution modelling provides worse/better results than the upscaled results of high-resolution modelling. The study area is an experimental vineyard field where proximal sensing images were obtained by an airborne platform and verification fluxes were measured via a flux tower. Modelled fluxes are in line with th…

Changes in Onset of Vegetation Growth on Svalbard, 2000–2020

2022

The global temperature is increasing, and this is affecting the vegetation phenology in many parts of the world. The most prominent changes occur at northern latitudes such as our study area, which is Svalbard, located between 76°30′N and 80°50′N. A cloud-free time series of MODIS-NDVI data was processed. The dataset was interpolated to daily data during the 2000–2020 period with a 231.65 m pixel resolution. The onset of vegetation growth was mapped with a NDVI threshold method which corresponds well with a recent Sentinel-2 NDVI-based mapping of the onset of vegetation growth, which was in turn validated by a network of in-situ phenological data from time lapse cameras. The results show th…

FUNCTIONALIZED HALLOYSITE NANOTUBES FOR ENHANCED REMOVAL OF Hg2+ IONS FROM AQUEOUS SOLUTIONS

2021

AbstractWater is essential for humans, animals, and plants; pollutants, usually derived from anthropogenic activities, can have a serious effect on its quality. Heavy metals are significant pollutants and are often highly toxic to living organisms, even at very low concentrations. Among the numerous removal techniques proposed, adsorption onto suitable adsorbent materials is considered to be one of the most promising. The objective of the current study was to determine the effectiveness of halloysite nanotubes (HNT) functionalized with organic amino or thiol groups as adsorbent materials to decontaminate polluted waters, using the removal of Hg2+ ions, one of the most dangerous heavy metals…

INTEGRAL and RXTE observations of accreting millisecond pulsar IGR J00291+5934 in outburst

2005

Simultaneous observations of the accretion-powered millisecond pulsar IGR J00291+5934 by International Gamma-Ray Astrophysics Laboratory and Rossi X-ray Timing Explorer during the 2004 December outburst are analysed. The average spectrum is well described by thermal Comptonization with an electron temperature of 50 keV and Thomson optical depth tau_T ~ 1 in a slab geometry. The spectral shape is almost constant during the outburst. We detect a spin-up of the pulsar with nudot=8.4x10E-13 Hz/s. The ISGRI data reveal the pulsation of X-rays at a period of 1.67 milliseconds up to ~150 keV. The pulsed fraction is shown to increase from 6 per cent at 6 keV to 12--20 per cent at 100 keV. This is n…

A directional spectral mixture analysis method: application to multiangular airborne measurements

2006

This study aims at developing an operational approach-namely, directional spectral mixture analysis (DISMA)-for retrieving vegetation parameters like fractional vegetation cover (FVC) and leaf area index (LAI) from multispectral and multiangular data. The approach attempts to highlight the consistency of one-dimensional models and linear mixture approaches. DISMA combines spectral signatures of soil and vegetation components with an analytical approximation of the radiative transfer equation, giving rise to a fast invertible bidirectional reflectance distribution function (BRDF) model of discontinuous canopies. Both the forward model and its inversion using a simple technique based on looku…

Field-portable Mössbauer spectroscopy on Earth, the Moon, Mars, and beyond

2011

ABSTRACT Iron occurs naturally as Fe 2+ , Fe 3+ , and, to a lesser extent, as Fe 0 . Many fundamental (bio)geochemical processes are based on redox cycling between these oxidation states. Mossbauer spectroscopy provides quantitative information about the distribution of Fe among its oxidation states, identification of Fe-bearing phases, and relative distribution of Fe among those phases. Portable, miniaturised Mossbauer spectrometers were developed for NASA9s Mars Exploration Rovers (in operation since 2004) and provide a means for non-destructive, in-situ field investigations. On Mars, these instruments provided evidence for aqueous activity with implications for habitability, were applied…