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Saba M.M.F.,National Institute for Space Research | Schulz W.,System Detection | Warner T.A.,South Dakota School of Mines and Technology | Campos L.Z.S.,National Institute for Space Research | And 4 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2010

Although positive lightning flashes to ground are not as frequent as negative flashes, their large amplitudes and destructive characteristics make understanding their parameters an important issue. This study summarizes the characteristics of 103 positive cloud-to-ground (+CG) flashes that have been recorded using high-speed video cameras (up to 11,800 frames per second) in three countries together with time-correlated data provided by lightning location systems (LLS). A large fraction of the +CG flashes (81%) produced just a single stroke, and the average multiplicity was 1.2 strokes per flash. All the subsequent strokes in multiple-stroke +CG flashes created a new ground termination except one. The geometric mean of 21 interstroke time intervals was 94 ms, which is about 1.5 times larger than the average interstroke interval in negative CG flashes (∼60 ms); 75% of the +CG flashes contained at least one long continuing current (LCC) 40 ms, and this percentage is significantly larger than in the negative flashes that produce LCCs (approximately 30%). The median estimated peak current (Ip) for 116 positive strokes that created new ground terminations was 39.4 kA. Positive strokes with a large Ip were usually followed by a LCC, and both of these parameters are threats in lightning protection. The characteristics presented here include the multiplicities of strokes and ground contacts, the percentage of single-stroke flashes, the average interstroke time interval, the durations of the continuing current, and the distributions of Ip, the total flash durations, and the 2-D leader speeds. Copyright 2010 by the American Geophysical Union. Source

Yang G.,Northwest University, China | Cui T.,System Detection | Wang Y.,Northwest University, China | Sun S.,Northwest University, China | And 4 more authors.
Proteomics | Year: 2013

As one of the most important post-translational modifications, the discovery, isolation, and identification of glycoproteins are becoming increasingly important. In this study, a Con A-magnetic particle conjugate-based method was utilized to selectively isolate the glycoproteins and their glycomes from the healthy donor and hepatocellular carcinoma (HCC) case sera. The isolated glycoproteins and their N-linked glycans were identified by LC-ESI-MS/MS and MALDI-TOF/TOF-MS, respectively. A total of 93 glycoproteins from the healthy donors and 85 glycoproteins from the HCC cases were identified. There were 34 different glycoproteins shown between the healthy donors (21/34) and the HCC cases (13/34). Twenty-eight glycans from the healthy donors and 30 glycans from the HCC cases were detected and there were 22 different glycans shown between the healthy donors (10/22) and HCC cases (12/22). Among these glycoproteins, 50 were known to be N-linked glycoproteins and three novel glycopeptides from two predicted potential glycoproteins were discovered. Moreover, lectin blotting, Western blotting and lectin/glyco-antibody microarrays were applied to definitely elucidate the change of selective protein expressions and their glycosylation levels, the results indicated that the differences of the identified glycoproteins between the healthy donors and HCC cases were caused by the change of both protein expression and their glycosylation levels. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yue Z.,CAS Shanghai Institute of Technical Physics | Yue Z.,System Detection | Li F.-M.,CAS Shanghai Institute of Technical Physics | Li F.-M.,System Detection
Journal of Applied Optics | Year: 2014

Based on the characteristics that the infrared polarization image can restrain background noise greatly, and can be more sensitive to target edge information, a polarization image fusion algorithm based on wavelet transform is proposed. It is mainly used in image fusion between the infrared radiation intensity image and the polarization degree image in order to increase the amount of information of the image. First, wavelet transform can make different wavelet scaling decomposition in each involved image respectively, and get the wavelet coefficients of each scale. Second, it uses the method of neighborhood average gradient on each scaling wavelet coefficients to get each scaling wavelet fusion coefficients. Last, it makes image reconstruction based on wavelet transform to get fused image. The comparison between the images and fused images shows that this method can keep image clarity of the radiation intensity image, as well as highlight the edge and contour information. Compared to the radiation intensity image, the average gradient of fused images increases by 112%, while compared to the polarization degree image, the standard deviation of fused images increases by 151%, and the information entropy of fused images increases by 38%. Source

Ballarotti M.G.,National Institute for Space Research | Medeiros C.,National Institute for Space Research | Saba M.M.F.,National Institute for Space Research | Schulz W.,System Detection | Pinto Jr. O.,National Institute for Space Research
Journal of Geophysical Research: Atmospheres | Year: 2012

This paper presents some parameters of negative cloud-to-ground lightning flashes in terms of frequency distribution. All data are based on so-called "accurate-stroke-count studies" from different climatological regions in the world and were already published in the literature with the exception of our measurements. We used GPS synchronized data from two digital high-speed cameras (at 1-8,000 frames/sec). The parameters considered in this study are: (1) continuing current duration, (2) time intervals between strokes, (3) number of strokes per flash and (4) total flash duration. The analysis includes Berger's data of Monte San Salvatore (Switzerland), which is the basis for lightning protection standards. The comparison suggests that despite of overall agreement of those parameters that some of them, currently used in protection standards, should be revised in order to be more realistic. © 2012 by the American Geophysical Union. Source

System Detection | Date: 2011-04-20

The present disclosure provides an optical device for selecting specific matter, such as plant matter. The device comprises a light source for emitting light having at least (3) wavelengths and for generating a combined beam of light having the at least 3 wavelengths. The device further comprises an optical element for directing a plurality of light beams towards matter including the specific matter. The optical element has first surface portions through which in use the plurality of component light beams are directed to the matter including the specific matter. Each component light beam is directed through a respective first surface portion that has an optical property that is selected so that light intensity differences between the component light beams are reduced. The optical device also comprises an optical filter for filtering reflected component light beams such that an intensity of light is reduced in a wavelengths range outside one or more wavelengths ranges that include the at least three wavelengths. Further, the optical device comprises a detector for detecting the reflected component light beams.

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