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TerraSAR-X (TS-X) is a new, fully polarized X-band synthetic aperture radar (SAR) satellite, which is a successor of the Spaceborne Imaging Radar X-band Synthetic Aperture Radar (SIR-X-SAR) and the SRTM. TS-X has provided high-quality image products over land and oceans for scientific and commercial users since its launch in June 2007. In this article, a new geophysical model function (GMF) is presented to retrieve sea surface wind speeds at a height of 10 m (U 10) based on TS-X data obtained with VV polarization in the ScanSAR, StripMap and Spotlight modes. The X-band GMF was validated by comparing the retrieved wind speeds from the TS-X data with in situ observations, the high-resolution limited area model (HIRLAM) and QuikSCAT scatterometer measurements. The bias and root mean square (RMS) values were 0.03 and 2.33 m s−1, respectively, when compared with the co-located wind measurements derived from QuikSCAT. To apply the newly developed GMF to the TS-X data obtained in HH polarization, we analysed the C-band SAR polarization models and extended them to the X-band SAR data. The sea surface wind speeds were retrieved using the X-band GMF from pairs of TS-X images obtained in dual-polarization mode (i.e. VV and HH). The retrieved results were also validated by comparing with QuikSCAT measurements and the results of the German Weather Service (DWD) atmospheric model. The obtained RMS was 2.50 m s−1 when compared with the co-located wind measurements derived from the QuikSCAT, and the absolute error was 2.24 m s−1 when compared with DWD results. [ABSTRACT FROM AUTHOR]

Background: Uniform size beads can be easily produced by vibration nozzle method. Objective: In this article, the pellets of polyethylene glycol are prepared by a vibration nozzle machine. Thickness of nozzle wall, rotation speed of stirrer, and voltage of excitation are discussed in this article. Results and Discussion: A nozzle wall of thickness ≤0.1 mm is applied to decrease the adherence of jet. The stirring device with 20 rotations/min on the upper side of condensed column is used to disperse unsolidified polyethylene glycol pellets. The effect of parameters including vibration frequency f, jet velocity v, and voltage of excitation V on the average diameter d and standard deviation SD% are investigated by response surface methodology and Weber equation. A very good linear regression between d and v/ f is presented under optimum V (in this article V = 3.0 V). Both high v and low SD% can also be obtained by optimum V [ABSTRACT FROM AUTHOR]

Ocean oil spills cause serious damage to the marine environment, especially around coastal waters. Synthetic aperture radar (SAR) has been proven to be a useful tool for oil spill detection under low to moderate wind conditions. SAR operates in the microwave band and the data is not affected by the cloud cover and day/night conditions. However, the operational application of SAR for oil spill detection in the ocean is limited by false alarm targets or lookalike phenomena such as low wind speed, natural films, etc. In this study, we develop analysis of variance (ANOVA) to extract the features based on their characteristic geometry, grey level and texture features in the SAR images. We further analysed a fuzzy logic algorithm to separate oil spills features from lookalikes. We trained this algorithm using 38 SAR images (11 ENVISAT-Advanced Synthetic Aperture Radar (ASAR) and 27 European Remote Sensing (ERS)-2 SAR images) with 120 known oil spills and 80 lookalikes to generate an oil spill probability of a dark pixel in a SAR image. An independent set of 26 SAR images were used to validate the algorithm and it was found that 80.9% of the oil spills were correctly classified, and 20.0% of the lookalikes were wrongly classified as oil spills. The complete algorithmic procedure was coded in Matlab7.0 using its Fuzzy Logic Toolbox. [ABSTRACT FROM AUTHOR]

A method for determining the cleavage position of a protein in enzymatic hydrolysis using high performance size-exclusion chromatography (HPSEC) was established, in terms of an example of bovine serum albumin (BSA) in tryptic hydrolysis. The molecular relative mass distribution of the hydrolysates is characterized by the chromatogram. Comparing the molecular relative mass of theoretical peptides based on the primary structure of BSA with that from experiments, the amino acid sequences of theoretical peptides matching to the peaks in chromatogram are obtained. Thus, the possible cleavage position of BSA in tryptic hydrolysis can be deduced by analyzing the appearing frequency of some amino acid serial. [ABSTRACT FROM AUTHOR]