Search results for " moisture"

How composition and process parameters affect volatile active compounds in biopolymer films

2012

Abstract Active edible films based on chitosan and containing an active aroma compound have been investigated. The influence of the composition of the film forming solution (solvent, plasticizers, nanoparticles, emulsifiers and aroma traps) and process parameters (temperature and viscosity) on drying kinetics, water content, colour, aroma compound retention and partition coefficient was studied. Solvent evaporation rate was increased by addition of ethanol. Water evaporation was delayed by glycerol. The aroma retention during film drying was directly related to the water content. The drying temperature had opposite influences according to the composition of the solvent and additives. Increa…

Ecohydrology in Mediterranean areas: a numerical model to describe growing seasons out of phase with precipitations

2007

Calibrating the effective scattering albedo in the SMOS algorithm: some first results

2016

International audience; This study focuses on the calibration of the effective scattering albedo (ω) of vegetation in the soil moisture (SM) retrieval at L-Band. Currently, in the SMOS Level 2 and 3 algorithms, the value of ω is set to 0 for low vegetation and ∼ 0.06 – 0.08 for forests. Different parameterizations of vegetation (in terms of ω values) were tested in this study. The possibility of combining soil roughness and vegetation contributions as a single parameter (“combined” method) leads to an important simplification in the algorithm and was also evaluated here. Following these assumptions, retrieved values of SMOS SM were compared with SM data measured over many in situ sites worl…

Flash floods in Mediterranean ephemeral streams in Valencia Region (Spain)

2016

Summary Ephemeral streams are typical Mediterranean fluvial systems with high risk of flash flooding, and few data are available about these systems in most locales. However, the SAIH network (Automatic Hydrological Information Systems) of the Jucar River Water Authority has been providing detailed information about ephemeral streams in Spain every 5 min since 1988. Using these data, we evaluated the processes of rainfall–runoff conversion and flood generation in five Mediterranean ephemeral streams ranging in size from 25 to 450 km 2 . To provide a general framework for hydrological analysis, the study included 142 flash flood events registered between 1989 and 2007. A more detailed analys…

ECOHYDROLOGICAL MODELLING IN MEDITERRANEAN AREAS AND WETLANDS

2010

La seguente dissertazione verte sul campo di ricerca noto come Ecoidrologia. Sebbene tale scienza, che studia le mutue interazioni fra ciclo idrologico e gli ecosistemi naturali, sia stata recentemente oggetto di svariati studi, alcuni dei suoi numerosi aspetti rimangono tuttavia ancora alquanto inesplorati. L’obiettivo principale della presente tesi è quello di rivisitare la letteratura scientifica esistente sull’argomento, cercando di adattare concetti e modelli sviluppati per certi ecosistemi anche alle peculiarità di altri ambienti meno studiati, come quelli aridi e semiaridi tipici della zona Mediterranea o le cosiddette “wetlands”, zone umide e paludose. In particolare, viene approfon…

Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using In Situ Measurements

2017

International audience; The Soil Moisture Active Passive (SMAP) mission Level-4 Surface and Root-Zone Soil Moisture (L4_SM) data product is generated by assimilating SMAP L-band brightness temperature observations into the NASA Catchment land surface model. The L4_SM product is available from 31 March 2015 to present (within 3 days from real time) and provides 3-hourly, global, 9-km resolution estimates of surface (0-5 cm) and root-zone (0-100 cm) soil moisture and land surface conditions. This study presents an overview of the L4_SM algorithm, validation approach, and product assessment versus in situ measurements. Core validation sites provide spatially averaged surface (root zone) soil m…

Soil moisture retrieval using crop water stress indicators

2008

Towards a long-term dataset of ELBARA-II measurements assisting SMOS level-3 land product and algorithm validation at the Valencia Anchor Station

2015

[EN] The Soil Moisture and Ocean Salinity (SMOS) mission was launched on 2nd November 2009 with the objective of providing global estimations of soil moisture and sea salinity. The main activity of the Valencia Anchor Station (VAS) is currently to assist in a long-term validation of SMOS land products. This study focus on a level 3 SMOS data validation with in situ measurements carried out in the period 2010-2012 over the VAS. ELBARA-II radiometer is placed in the VAS area, observing a vineyard field considered as representative of a major proportion of an area of 50×50 km, enough to cover a SMOS footprint. Brightness temperatures (TB) acquired by ELBARA-II have been compared to those obser…

New trials in the consolidation of waterlogged archaeological wood with different acetone-carried products

2011

Some acetone-carried consolidants for waterlogged archaeological wood were tested in order to evaluate treatments able to save time and energy. In details, colophony (rosin), two esterified colophonies (Rosin 100® and Rosin 459®), a mixture of colophony with PEG 3400 and a vinyl acetate - vinyl versate copolymer (Vinavil 8020S®) were tested. The treatments were carried out at temperatures of 20 and 35 °C on waterlogged maritime pine, elm, oak and beech. The materials came from the archaeological Site of the ancient ships of Pisa (Tuscany, Italy) and were dated back to VII cent. BC – II cent. AD. To evaluate the processes, equilibrium moisture content and dimensional stability of treated woo…

Assessment of performance degradation of hybrid flax-glass fiber reinforced epoxy composites during a salt spray fog/dry aging cycle

2022

The main goal of this paper is the evaluation of the performances reversibility of hybrid composites when they are dried after being aged in salt-fog environment. To this aim, epoxy composites reinforced with flax and glass fabrics respectively in the internal and external laminae were at first exposed to salt-fog (i.e., identified as wet phase) and then stored in controlled conditions (i.e., identified as dry phase). The flexural properties evolution of these composites as well as their water uptake and contact angle were monitored at varying time of both phases. The flexural strength and modulus of hybrid composites is 23.4% (17.9%) and 15.5% (12.9%) lower than unaged ones after 30 (15) d…