Sensitivity equations and calibration requirements on airborne interferometry

The usage of an airborne interferometric SAR to mass map production is strongly dependent on the capability of performing the data processing in a near automatic mode. One of the main limitations is related to both the accurate calibration of the system parameters, its stability from flight to flight and the correct in-flight recording of aircraft position and attitude. The unstable movements of an airborne SAR platform, if recorded in an accurate manner, can be corrected during the processing step. Measurement errors and time drifts lead to location errors in the final DEM. The system requirements in both accuracy and stability to fulfil a quality-mapping requirement can be resolved from the sensitivity equations. The same equations can be also used to calibrate the system parameters from the location errors on the imaging of well-known targets, usually corner reflectors.Peer ReviewedPostprint (published version

Six years of study on fast growing forest plantations catchments in the Northwest of Spain

Data on water balance in three fast growing forest plantations experimental catchments in the northwest of Spain are presented. Two watersheds are covered by Eucalyptus globulus and other is covered by Pinus pinaster. During the six years of study severa1 perturbations occurred. In 1989 two consecutives wildfires affected to one E. globulus watershed. The second fire also bumed the other eucalyptus watershed. All eucalyptus were felled since 1991 to 1992. Also 25% of the watershed area in the pine catchment was cutted in 1991. Quick changes in the hydrologycal regimen took place after these perturbations. The very fast recovering capacity after fire and cutting of Eucalyptus globulus facilitated the retum to pre-fire hydrologic parameter values within only a few years. Before perturbations occurred, nutrient balances were very conservative, and were similar among the cathments. This indicates a good performance on the part of both tree plantations. Water comsumption for pine and eucalyptus stands was very similar

Modificant els enzims

Els enzims són proteïnes que participen en els processos biològics, regulant la velocitat de les reaccions químiques. Investigadors del Departament de Bioquímica i Biologia Molecular de la UAB estan estudiant com alterar artificialment l'estructura dels enzims per modificar-ne el seu funcionament

An Overview of the Ecological Values of Soumar Wetland on Waterbirds Diversity

The diversity and richness of the waterbird community is the main criterion used to classify wetlands as Ramsar and/or IBA sites. This study was carried out in the Soumar wetland (Setif province — northeastукт Algeria) from September 2019 to September 2020. Our aim was to study the ecological values of this wetland and the status of waterbirds. We recorded a total of 23 species belonging to 11 families. June was the most diverse month of the year (Shannon–Weaver and Simpson indices reached the maximum). October was the most equitable month (equitability reached maximum). We noted four key species according to IUCN status: Ferruginous Duck, Aythya nyroca (Near Threatened), Common, Pochard Aythya ferina (Vulnerable), White-headed, Duck Oxyura leucocephala (Endangered) and Northern Lapwing, Vanellus vanellus (Near Threatened). The main phenological status of waterbirds in Soumar was breeding or sedentary (26 % and 21 % respectively). The geographical location of the Soumar wetland and its diversity profile require a local management plan (depending on the waterbirds and their conservation), allowing the Soumar wetland to join the Ramsar network

Correlation Between Structure, Microstructure and Dielectric Properties of Bi7Fe3Ti3O21 Ceramics Obtained in Different Conditions

Multiferroic six-layer Aurivillius type Bi7Fe3Ti3O21 ceramics was obtained by conventional mixed oxides method. The final sintering process was taken in several different sintering times, which determined changes in properties of discussed ceramic material. The structure and dielectric properties of the material are reported. In order to examine the technological conditions on the crystal structure, XRD analysis was carried out. The microstructure, as well as the quantitative and qualitative analysis of the chemical composition were investigated by scanning electron microscope with an energy dispersion spectrometer. The main purpose of the paper is to present the effect of sintering time on the microstructure, crystallographic structure and dielectric properties of Bi7Fe3Ti3O21 ceramics

Feasibility of Ultra-short Term Complexity Analysis of Heart Rate Variability in Resting State and During Orthostatic Stress

In this work, we study ultra-short term (UST) complexity of Heart Rate Variability (HRV) and its agreement with analysis of standard short-term (ST) HRV recordings obtained at rest and during orthostatic stress. Conditional Entropy (CE) measures have been computed using both a linear Gaussian approximation and a more accurate model-free approach based on nearest neighbors. The agreement between UST and ST indices has been compared via statistical tests and correlation analysis, suggesting the feasibility of exploiting faster algorithms and shorter time series for detecting changes in cardiovascular control during various states