Search results for "microwave"
showing 10 items of 693 documents
Electron cyclotron resonance ion source plasma chamber studies using a network analyzer as a loaded cavity probe
2012
A method and first results utilizing a network analyzer as a loaded cavity probe to study the resonance properties of a plasma filled electron cyclotron resonance ion source (ECRIS) plasma chamber are presented. The loaded cavity measurements have been performed using a dual port technique, in which two separate waveguides were used simultaneously. One port was used to ignite and sustain the plasma with a microwave source operating around 11 GHz and the other was used to probe the cavity properties with the network analyzer using a frequency range around 14 GHz. The first results obtained with the JYFL 14 GHz ECRIS demonstrate that the presence of plasma has significant effects on the reson…
Advances in Microwave and Submillimeter-Wave Dielectric Spectroscopic Techniques and their Applications
2007
L-Band radiative properties of vine vegetation at the MELBEX III SMOS Cal/Val Site
2012
Radiative properties at 1.4 GHz of vine vegetation are investigated by measuring brightness temperatures with the ETH L-band Radiometer II (ELBARA II) operated on a tower at the Mediterranean Ecosystem L-band Characterisation Experiment III (MELBEX III) field site in Spain. To this aim, experiments with and without a reflecting foil placed under the vines were performed for the vegetation winter and summer states, respectively, to provide prevailingly information on vegetation transmissivities. The resulting parameters, which can be considered as "ground truth" for the MELBEX III vineyard, were retrieved from brightness temperature at horizontal and vertical polarization measured at observa…
The SMOS mediterranean ecosystem L-band characterisation experiment (MELBEX) over natural shrubs
2010
10 páginas, 5 figuras, 7 tablas.
Evaluation of the most recent reprocessed SMOS soil moisture products: Comparison between SMOS level 3 V246 and V272
2015
International audience; Soil Moisture and Ocean Salinity (SMOS) satellite has been providing surface soil moisture (SSM) and ocean salinity (OS) retrievals at L-band for five years (2010–2014). During these five years, the SSM retrieval algorithm i.e. the L-MEB (L-Band Microwave Emission of the Biosphere [1] model has been progressively improved and hence results in different versions of the SMOS SSM products. This study aims at evaluating the last improvement in the SSM products of the most recent SMOS level 3 (SMOSL3) reprocessing (SMOSL3_2.72) vs. an earlier version (SMOSL3_246). Correlation, bias, Root Mean Square Difference (RMSD) and unbiased RMSD (unbRMSD) were used as perform…
Fluxon dynamics in Li–Al codoped MgB2 by microwave surface resistance measurements
2010
The magnetic-field-induced variations of the microwave surface resistance, Rs, have been investigated in ceramic Mg_(1-x)(LiAl)_xB_2, with x in the range 0.1 - 0.4. The measurements have been performed on increasing and decreasing the DC magnetic field, H0, at fixed temperatures. At low temperatures, we have observed a magnetic hysteresis in the Rs(H0) curves in all the investigated samples. On increasing the temperature, the range of H0 in which the hysteretic behavior is visible shrinks; however, in the sample with x=0.1 it is present up to temperatures close to Tc. We show that the field dependence of Rs can be quantitatively justified taking into account the critical-state effects on th…
Anomalous hysteretic behaviour of the microwave surface resistance in MgB2 superconductor
2007
Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system
2016
International audience; Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds …