Land-use classification in central Spain using SIR-A and MSS imagery

Abstract

Methods for making more efficient use of synthetic aperture radar (SAR) imagery are considered. Local standard deviation and autocorrelation texture measures are used to provide information on the spatial variability in the scattering cross-section. Use of these statistics in a window of 180×180m improved classification success rates from 39 to 66 per cent with digitized shuttle imaging radar (S1R-A) data. Multispectral scanner (MSS) achieves 70 per cent success with the same window size and, by combining this with SAR, a 78 per cent success rate is reached.     

A simple geometrical model for analysing the spectral response of a citrus canopy using satellite images †

Abstract

A simple geometrical model has been proposed for a citrus canopy. We assume the citrus orchard to be a lattice structure, with the trees positioned at its points and where the composite-scene reflectance is the sum of the reflectance of its individual components as weighted by their respective surfaces within a unit area. The model has been used to analyse the citrus spectral response obtained from Landsat-5 TM images for winter and summer, where the status of the orchard is different. The correlations between spectral and geometrical data show the influence of per cent crop cover, shadows and background in the composite scene reflectance. We conclude that the summer images could be more useful than the winter ones for parcel classification according to per cent crop cover.     

DATA ANALYSIS PRIOR TO A CIRCULATION MODEL IN GRAN CANARIA

The use of numerical models in physical oceanography, with the aim of reproducing and predicting water movements, is a common practice, especially for coastal areas. Nevertheless, results will be accurate only if the assumptions are appropriate and include all significant characteristics of the domain under modeling. Two-dimensional models are often used for shallow-water areas, but the implicit assumptions of conservation of a characteristic vertical profile for the horizontal velocities all over the domain and negligible vertical circulation must be exhaustively checked. Here a case is presented in which two-dimensionality would have led to inaccurate results, as the analysis of the field data showed a three-layer behavior. This case concerns the eastern coast of Gran Canaria island (Canary Islands) and illustrates how mathematical models will describe the phenomena they try to represent correctly only if all assumptions are right.     

Thiophene‐ and silarylene‐containing polyesters. Resonance effect on conductivity after polarization in an external electric field

Polyesters were synthesized by direct polycondensation of thiophene‐2,5‐dicarboxylic acid and five different silarylene‐containing diphenols using a tosyl chloride/pyridine/N,N‐dimethylformamide system as a condensing agent. Polymers were obtained in good yields and were characterized using Fourier transform infrared and NMR (¹H, ¹³C, 135‐DEPT and ²⁹Si) spectroscopy and elemental analysis. All polymers were completely soluble in aprotic organic polar solvents such as dimethylformamide, dimethylsulfoxide and N‐methyl‐2‐pyrrolidone. The range of effective mass of the polymers (m/z) was 1 × 10⁵–2 × 10⁵, determined using electrospray ionization mass spectrometry. Asymmetry and steric hindrance prevented dense packing of the polymeric chains, showing glass transition temperatures between ? 78 and ? 51 °C and loss of thermal stability at 177–199 °C (10% weight loss). Additionally, the melting points of the polyesters were found to be in the range 62–67 °C. Because of this, the samples were semi‐solid at room temperature. The optical band gaps of the polymers were observed between 4.54 and 4.48 eV, corresponding in all cases to insulator behavior. The molecular structure of the samples was studied using X‐ray diffraction, showing a degree of order that was associated with two monoclinic lattices. Additionally, the conductivity was studied using a two‐point method with contacts on top of polymer films. Prior to the electrical measurement, the samples were polarized in an external electric field of 0.8 to 6.4 V cm^?1, and the alignment of the dipoles increased the electrical conductivity. Copyright © 2012 Society of Chemical Industry     

Polyphosphates as inhibitors of surface mould growth on hard cheese during ripening

A novel treatment using polyphosphates to protect cheeses against superficial mould growth was assayed. The treatments were: control commercial paint with natamycin (I), commercial paint based on polyvinyl–water (II), immersion in a saturated solution of polyphosphate (III), immersion and commercial paint (IV), commercial paint of polyphosphate solutions (V) and immersion and commercial paint of a saturated solution of polyphosphates (VI). The cheeses were ripened for 6 months. Superficial mould growth was inhibited in groups IV and VI when compared to cheeses from the control group (I). Statistical sensory analysis made between cheeses from groups IV and I (control) showed no significant differences.     

Mass spectrometry fragmentation pattern of coloured flavanol‐anthocyanin and anthocyanin‐flavanol derivatives in aged red wines of Rioja

Background and Aims: During wine ageing, a great variety of reactions take place, resulting in an immense variety of products whose structure sometimes remains unknown. The aim of this work is the study of different fragmentation patterns of flavanol‐anthocyanin derivatives formed along the wine ageing; these patterns are useful for elucidating the different structures of these compounds and other new related ones. Methods and Results: Several wines from the Protected Denomination of Origin Rioja have been studied by an analytical method that combines column chromatography and high‐performance liquid chromatography with diode array and mass and tandem mass spectrometric detections. Thirty‐five coloured flavanol‐anthocyanin compounds formed by direct reaction or by acetaldehyde‐mediated condensation have been identified. For direct reaction derivatives, two different fragmentation patterns (one of them not previously reported) have been observed depending on the position of flavanol in the coloured derivative. Several compounds have been identified in aged wines for the first time to the authors' knowledge, like (+)‐gallocatechin‐cyanidin‐3‐glucoside and (+)‐catechin‐cyanidin‐3‐glucoside Conclusions: The developed analytical procedure has allowed the identification of some compounds for the first time, and two different fragmentation patterns have been observed depending on the position of flavanol in the pigment. Significance of the Study: The establishment of different fragmentation patterns allows the structural elucidation of unknown compounds.