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31.
Influence of growth conditions on biofilm development and mass transfer at the bulk/biofilm interface 总被引:8,自引:0,他引:8
In a long-term study on heterotrophic biofilms in tube reactors, this investigation focused on mass transfer at the bulk/biofilm interface, biofilm density and substrate conversion rates. Several biofilms were cultivated under different substrate and hydrodynamic conditions. Oxygen concentration profiles were measured with microelectrodes in the biofilm and in the boundary layer directly in the biofilm tube reactors. The thickness of the concentration boundary layer was found to depend on the surface structure of the biofilm. The hydrodynamic conditions and the substrate load during the growth phase of the biofilm in biofilm systems are two key parameters that influence the biofilm growth, particularly the structure, density and thickness. The measured substrate conversion rates, biofilm densities and the boundary layer thickness were used to formulate an equation for the mass transfer in biofilm tube reactors. 相似文献
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随着全球变暖,世界范围内关于减少温室气体排放的法规要求也日益严格。针对二氧化碳排放问题的很多机会存在于供应链管理之中,这迫使公司寻找新的方法来进行有效的碳管理;从采购和生产到配送和产品再生。供应链管理中的权衡不再只是关于成本.服务和质量,而是关于成本.服务.质量和碳排放。 相似文献
35.
Andrea Kaiser Katja I. Hartmann Dietmar R. Kammerer Reinhold Carle 《European Food Research and Technology》2013,237(3):353-365
Initial heating was applied as the first processing step in the production of innovative pasty celeriac products. For this purpose, celeriac was converted into a paste and subsequently heated at 90 and 100 °C for 5–10 min. Alternatively, the fresh plant material was blanched prior to mincing. For the first time, phenolic compounds in celeriac were characterized by high-performance liquid chromatography coupled with mass spectrometry (LC–MSn). Among the 14 phenolics detected, several caffeic, ferulic and quinic acid derivatives as well as malonylated and acetylated flavonoid derivatives were newly identified. Upon thermal treatment, the antioxidant capacities (TEAC assay) and the total phenolic contents remained virtually unchanged. The antioxidant capacities of heated samples determined by the FRAP assay were even higher than those of the unheated control. The contents of the main phenolic compound apiin decreased upon heat treatment, whereas the levels of the minor compounds malonylapiin A and B increased. Only by extended steam- and water-blanching at 100 °C, respectively, complete inactivation of peroxidase and polyphenol oxidase was achieved. The obtained celeriac products were characterized by their bright white color. Consequently, blanching is recommended as the initial operation in the processing of celeriac into novel pasty products. 相似文献
36.
In the process of digitizing the geometry and appearance of 3D objects, texture registration is a necessary step that solves
the 2D–3D mapping between the 2D texture images and the 3D geometric model. For evaluation of texture registration with ground
truth, accurate datasets can be obtained with a complex setup consisting of calibrated geometry and texture capture devices.
We do not have any knowledge of such evaluation performed; current evaluations reflect, at their best, the precision achieved
by the algorithms, but fail to identify a possible bias. We propose a new evaluation measure based on the epipolar geometry
of texture image pairs, with the advantage that the ground truth can be extracted solely from the texture images, independent
of the 3D acquisition. We developed a noise model suitable to our purpose and analysed three distance measures based on epipolar
geometry, well known in the computer vision community, to find new theoretical and experimental results. Finally, using the
proposed framework, we evaluated a texture registration algorithm based on mutual information and found that its accuracy
was under half-pixel. 相似文献
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Großzugversuche. Versuche mit Hillproben. Werkstoffe: RSt 37-2, St 52-3, 22 NiMoCr 37, StE 47, StE 70. Kraft-Verlängerungs-Diagramme. J-Integral in Abhängigkeit von der Verlängerung. J-Werte bei gerade erreichtem vollplastischen Zustand Jgy und bei Beginn des stabilen Rißwachstums Ji. Einfluß der Fließgrenze. Kritische J-Werte in Abhängigkeit von der Temperatur. Einfluß der Kerbschärfe: Kerbe und Risse; erstmaliges Auftreten des stabilen Anrisses; duktiler Bruch. Zusammenhang zwischen bleibender Verschiebung der Kerbflanken bis zum Bruch bei Ts und Hauptformänderung bis zum Bruch bei der Hillprobe. Korrelation zwischen der Bruchspannung der Hillprobe und der größten Hauptnormalspannung im Kerbgrund bei Beginn des stabilen Rißwachstums. Zusammenhang zwischen der Hauptformänderung bis zum Bruch bei der Hillprobe und dem J-Wert bei Beginn des stabilen Rißwachstums. 相似文献
39.
The development of a direct competitive ELISA for the detection of a broad range of sulfonylurea herbicides (SUs) is described. Polyclonal antibodies were generated in rabbits using three different immunizing haptens. Antiserum with the broadest specificity was obtained with a mesosulfuronbenzylamine derivative which was coupled via a succinic acid spacer to keyhole limpet hemocyanine. A heterologous enzyme tracer which did not contain the succinic acid bridge was prepared using activated horseradish peroxidase. The direct competitive ELISA was optimized and applied for spiked tap and surface water samples. From 30 SUs, 8 compounds showed a molar cross-reactivity (CR) higher than 100% (this value was set for the hapten) and 11 compounds CRs between 10% and 100%. The ELISA can detect 16 SUs at a concentration of 0.1 microg/L or lower. Different surface and tap water samples were spiked with chlorimuron ethyl, metsulfuron methyl, or primisulfuron methyl at concentrations of 100, 200, or 500 ng/L and subsequently analyzed by both ELISA and HPLC-UV. Correlation analysis revealed good agreement between both methods (r2 = 0.983/0.948/0.982; n = 21 for each analyte). Using ELISA, no sample pretreatment other than filtration was necessary. 相似文献
40.
Kraftkontrollierte Zug-Druck-Wechselversuche an vergütetem Stahl 42 CrMo4. Ermittlung von Wechselverformungs- und Mitteldehnungskurven bei unterschiedlichen Kombinationen von Mittelspannung und Spannungsamplitude unter Raumtemperaturbedingungen. Konsequenzen für übliche Dauerfestigkeitsschaubilder. 相似文献