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71.
72.
PCB, PCDD and PCDF residues in fin and non-fin fish products from the Canadian retail market 2002 总被引:1,自引:0,他引:1
Rawn DF Forsyth DS Ryan JJ Breakell K Verigin V Nicolidakis H Hayward S Laffey P Conacher HB 《The Science of the total environment》2006,359(1-3):101-110
Fish products (n=129) available on the Canadian retail market were collected and analyzed for levels of PCBs, PCDDs and PCDFs during the spring of 2002. The collection included samples from eight fish groups (Arctic char, crab, mussels, oysters, salmon, shrimp, tilapia, trout) from the wild and those raised on fish farms, as available. Sample collection included both domestic and imported fish products, however, no significant difference in residue levels was observed between these groups of fish products. Salmon samples were found to contain the highest concentration of sigmaPCBs (geometric mean 12.9 ng/g wet weight), while crab samples had greatest sigmaPCDD/F levels (geometric mean 0.002 ng/g wet weight). The geometric mean of the total toxic equivalents (WHO-TEQ) ranged from 0.06 pg WHO-TEQ/g whole weight in farmed shrimp to 1.1 pg WHO-TEQ/g whole weight in farmed salmon samples. PCB 153, 138, 118 and 101 were the dominant congeners observed in fish product samples studied, while 1,2,3,7,8-pentachlorodibenzodioxin and 2,3,7,8-tetrachlorodibenzofuran contributed the most to total PCDD and PCDF loadings. Lipid content was positively correlated to sigmaPCB levels; however, no relationship between lipid content and sigmaPCDD/F concentrations was established. SigmaPCB levels were below the Canadian guideline value for PCBs in fish and fish products (2000 ng/g). Similarly, 2,3,7,8-TCDD levels in all fish products were below the Canadian guideline value (0.020 ng/g). 相似文献
73.
Ekaterina Sirazitdinova Igor Pesic Patrick Schwehn Hyuk Song Matthias Satzger Marcus Sattler Dorothea Weingärtner Thomas M. Deserno 《Computer-Aided Civil and Infrastructure Engineering》2018,33(7):602-613
A system for fully automatic contact‐less image‐based measurement of volumetric flow rate in urban drainage structures is presented. The hardware includes two original equipment manufacturer cameras and a single‐board computer on which our custom image processing software is running. The value of water discharge depends on the surface velocity, water level and channel's geometry. The level of the flow is estimated as the difference between distances from the camera to the water surface and from the camera to the channel's bottom. Camera‐to‐water distance is recovered automatically using large‐scale stereo‐matching, whereas the distance to the channel's bottom is measured upon installation. Surface velocity is calculated using cross‐correlation template matching: individual natural particles in the flow are detected and tracked throughout the sequence of images recorded over a fixed time interval. The relative discharge computation error is lower than 1.34% of the theoretical maximal discharge for a given location, which makes our system competitive to commercial components such as ultrasonic flow meters, while using cheaper technologies. 相似文献
74.
75.
Graph grammars are a promising tool for solving picture processing problems. However, the application of graph grammars to
diagram recognition has been limited to rather simple analysis of local symbol configurations. This paper introduces the Build-Weed-Incorporate
programming style for graph grammars and shows its application in determining the meaning of complex diagrams, where the interaction
among physically distant symbols is semantically important. Diagram recognition can be divided into two stages: symbol recognition
and high-level recognition. Symbol recognition has been studied extensively in the literature. In this work we assume the
existence of a symbol recognizer and use a graph grammar to assemble the diagram's information content from the symbols and
their spatial relationships. The Build-Weed-Incorporate approach is demonstrated by a detailed discussion of a graph grammar
for high-level recognition of music notation.
See Appendix A for an illustration of the terms for musical symbols used in this paper. 相似文献
76.
Norbert Helle Anne Wolbert Bettina Linke Dorothea Ehlers Karl -Ernst Krüger 《European Food Research and Technology》1995,201(4):355-360
This paper describes the development of a method for the identification of irradiated fresh fruits by measurement of the e.p.r. spectra of pips, kernels or stones. Measurement parameters were optimized and the irradiation specific spectrum was assigned to a cellulose radical by comparison with the e.p.r. spectrum of pure cellulose. Several fruits especially different varieties of strawberries were examined giving the following results: Detectable minimum doses were between 0.4 kGy and 0.9 kGy and the intensity of the irradiation specific signals was found to be linear up to doses of 11 kGy. The lifetime of the specific radicals (at room temperature and at deep freezing temperatures) was long enough compared to the storage time of fresh fruits. Additional information about the nature of the unspecific central signal was gained measuring the samples which were stored at different temperatures. The main conclusion of this study is that the e.p.r. method seemes to be well suited for the use in routine control and should be tested in an intercomparison to establish a routine method for the identification of irradiated fresh fruits. 相似文献
77.
Dorothea M. Beutling Janina Peçonek Helga Stan-Lotter 《European Food Research and Technology》2009,229(5):725-730
The species Chromohalobacter beijerinckii comb. nov. was recently proposed in order to accommodate strain Pseudomonas beijerinckii Hof 1935, which was found in salted beans, and a novel isolate, strain 3b, which was obtained from salted herrings of the
Baltic sea. The species is psychrophilic, growing from 5 to 42 °C and highly salt-tolerant, growing between 0.5 and 25% NaCl.
Of interest to food microbiology are several properties, which are described here, such as the enzymatic activity of Ch. beijerinckii strain 3b against fish protein, cod liver oil and butter. In addition, the strain possesses decarboxylases of lysine, tyrosine
and histidine and can thus be a producer of biogenic amines, mainly histamine and tyramine. In media containing 10% NaCl,
Ch. beijerinckii strain 3b is resistant to the antibiotics bacitracin, chloramphenicol, streptomycin, tetracycline and novobiocin. The potential
impact of these properties, especially of the biogenic amine content in salted food, which were not known so far from other
species of the genus Chromohalobacter, is discussed. 相似文献
78.
79.
80.
Parabolic trough power plants with direct steam generation are a promising option for future cost reduction in comparison to the SEGS type technology. These new solar thermal power plants require innovative storage concepts, where the two-phase heat transfer fluid poses a major challenge. A three-part storage system is proposed where a phase change material (PCM) storage will be deployed for the two-phase evaporation, while concrete storage will be used for storing sensible heat, i.e. for preheating of water and superheating of steam. A storage system with a total storage capacity of approx. 1 MW h is described, combining a PCM module and a concrete module. The storage modules have been constructed for testing in a DSG-test facility specially erected at a conventional power plant of Endesa in Carboneras (Spain). Commissioning of the storage system started in May 2010; testing under real steam conditions around 100 bar will begin in August 2010. 相似文献