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11.
In many EU countries, the infrastructures for supplying electricity and gas (electricity networks, gas pipelines, and storage facilities) are still properties of the so-called vertically integrated undertakings (VIU) responsible for the extraction or generation, supply, and transmission and distribution of the energy. While competition can be promoted in the generation/production and supply side of the vertical integration, transmission and distribution segments remain natural monopolies that hinder market mechanisms. Vertical integration simply raises the possibility for incumbents to favor their own divisions and to block new entrants. As a result, non-discriminatory and equal access to the electricity and gas transmission and distribution networks, also LNG and storage facilities, is crucial to foster competition in politically delicate structures of the electricity and gas markets. 相似文献
12.
Axial Strain Accelerations Approach for Damage Localization in Statically Determinate Truss Structures 下载免费PDF全文
Bartlomiej Blachowski Yonghui An Billie F. Spencer Jr. Jinping Ou 《Computer-Aided Civil and Infrastructure Engineering》2017,32(4):304-318
This work proposes an efficient and reliable method for damage localization in truss structures. The damage is localized on the basis of measured acceleration signals of the structure followed by simple statistical signal processing. It has three main advantages over many existing methods. First, it can be directly applied to real engineering structures without the need of identifying modal parameters or solving any global optimization problem. Second, the proposed method has higher sensitivity to damage than some other frequently used methods and allows to localize damage as small as a few percentages. Third, it is a model‐free method, which does not require precise finite element model development or updating. Validation of the method has been conducted on numerical examples and laboratory‐scale trusses. Two types of frequently used trusses have been selected for this study, namely, Howe and Bailey trusses. The presented experimental validation of the method shows its efficiency and robustness for damage localization in truss structures. 相似文献
13.
Ida Borgh Peter Hedström Joakim Odqvist Annika Borgenstam John Ågren Ali Gholinia Bartlomiej Winiarski Philip J. Withers George E. Thompson Ken Mingard Mark G. Gee 《Acta Materialia》2013,61(13):4726-4733
In the present work, the size distribution and shape of WC grains in cemented carbides (WC–Co), with different Co contents, have been investigated in three dimensions. Direct three-dimensional (3-D) measurements, using focused ion beam serial sectioning and electron backscattered diffraction (EBSD), were performed and a 3-D microstructure was reconstructed. These measurements were supplemented by two-dimensional (2-D) EBSD and scanning electron microscopy on extracted WC grains. The data from 2-D EBSD collected on planar sections were transformed to three dimensions using a recently developed statistical method based on an iterative inverse Saltykov procedure. This stereological analysis revealed that the assumed spherical shape of WC grains during the Saltykov method is reasonable and the estimated 3-D size distribution is qualitatively in good agreement with the actual distribution measured from 3-D EBSD. Although the spherical assumption is generally fair, the WC grains have both faceted and rounded surfaces. This is a consequence of the relatively low amount of liquid phase during sintering, which makes impingements significant. Furthermore, the observed terraced surface structure of some WC grains suggests that 2-D nucleation is the chief coarsening mechanism to consider. 相似文献
14.
Völler GH Krawczyk JM Pesic A Krawczyk B Nachtigall J Süssmuth RD 《Chembiochem : a European journal of chemical biology》2012,13(8):1174-1183
Lantibiotics are a large group of ribosomally synthesized peptides post-translationally modified to incorporate the amino acid lanthionine. They are classified, according to their biosynthetic pathway and bioactivity, into three major subtypes. Of Actinomycetes type III lantibiotics, only four peptides (SapB, SapT, LabA1, and LabA2) have been described and structurally characterized, although homologous gene clusters are abundant in other Actinomycetes. All these gene clusters share a similar architecture with a characteristic Ser/Ser/Cys motif in precursor peptides, which has previously been suggested to act as a precursor for lanthionine (SapB) and labionin (LabA2) rings. Mass spectrometry screening led to the discovery and characterization of three new representatives of type III lantibiotics: Avermipeptin (Avi), Erythreapeptin (Ery), and Griseopeptin (Gri) from Streptomyces avermitilis DSM 46492, Saccharopolyspora erythraea NRRL 2338, and Streptomyces griseus DSM 40236, respectively. Apart from the assignment of these peptides to their corresponding gene clusters, additional investigations on Avi, Ery and Gri peptides indicate stepwise leader processing by putative aminopeptidase-like protease(s), thus yielding mixtures of differently N-terminal-processed lantibiotic peptides. Similar peptide processing was observed for a heterologously expressed eryth biosynthetic gene cluster expressed in a Streptomyces host system. Remarkably, all isolates of the new type III lantibiotics contain both the amino acids lanthionine and labionin, thus implying dual-mode cyclase activity of the processing lyase-kinase-cyclase enzymes. These findings have implications for the structures and maturation of other type III lantibiotics from Actinomycetes. 相似文献
15.
Chun Hin Ng Orawan Winther-Jensen Bartlomiej Kolodziejczyk C. André Ohlin Bjorn Winther-Jensen 《International Journal of Hydrogen Energy》2014
Vapour phase polymerised (VPP) polybithiophene (PBTh) on glassy carbon is revealed to be an efficient photo-electrocatalytic electrode for the hydrogen evolution reaction (HER). An onset potential of −0.03 V vs SCE for the HER is observed on illumination using visible light in 0.1 mol L−1 phosphate buffer at pH 6.9, 600 mV lower in energy than E0. Hydrogen evolution is confirmed using gas chromatography with a calculated faradaic efficiency of 34% when holding at a potential of −0.5 V. Importantly, this process occurs without platinum and under neutral aqueous conditions thus revealing a significant but overlooked application for PBTh: a potential low-cost cathode material for the splitting of water. 相似文献
16.
This article uses the protection motivation theory to study the impact of information security awareness on desktop security behavior. It contributes to the literature by examining the roles played by awareness, an important antecedent to the cognitive processes in the protection motivation theory. The findings indicate that security awareness significantly affects perceived severity, response efficacy, self-efficacy, and response cost. Constructs in the coping appraisal process (except response cost), in turn, significantly impact recommended security behavior. 相似文献
17.
18.
A. P rez Pujol R. X. Valenzuela A. Fuerte E. Wloch A. Kubacka Z. Olejniczak B. Sulikowski V. Cort s Corber n 《Catalysis Today》2003,78(1-4):247-256
The catalytic performance in the oxidehydrogenation (ODH) of propane of vanadium oxide catalysts supported on gallium oxide, VOx/Ga2O3, with vanadium coverages lower or near the theoretical monolayer has been studied as a function of the vanadium content and compared with those of other known effective V–M–O (M=Mg, Ca) catalysts. Catalyst activity was very high and increased with the increase of vanadium loading in the range studied, while the selectivity trend was similar for the studied catalysts, excepting that with the lower V content. FT-Raman and 51V solid state NMR spectroscopies show that for coverages below the theoretical monolayer vanadium atoms are in tetrahedral co-ordination either in isolated or polymeric species, while the onset of vanadia formation is detected above that coverage. Interestingly, these catalysts show an one order of magnitude higher area-specific rate, similar initial olefin selectivity and slightly higher selectivity decrease with the increase of conversion than the best VMgO catalyst. This is due to the high intrinsic activity of isolated tetrahedral vanadium species. The combination of these factors produces an enhanced olefin productivity of V–Ga–O catalysts. 相似文献
19.
Beng Guat Ooi Laura E. Wanamaker Bartlomiej M. Markuszewski & Ngee Sing Chong 《International Journal of Food Science & Technology》2008,43(6):1111-1120
The non‐wine Saccharomyces cerevisiae strain of 96581 was found to be a promising candidate for the production of white wine. It produced wines with fusel alcohols that were 57% higher than those produced by the wine yeasts studied and was also more efficient in the production of 2‐phenethyl acetate and 3‐methyl‐1‐butanol acetate. This study also shows that there is a difference in the ester‐formation efficiency for acetates relative to C6, C8 and C10 fatty acid esters for all the studied yeast strains. Therefore, it supports the view that other unidentified enzymes besides those regulated by ATF1 and ATF2 genes are involved in the production of ethyl esters of C6–C10 fatty acids. DNA analysis of the 25S, 18S, 5.8S and 5S ribosomal DNA genes in these strains showed high conservation. Despite the closely related nature of these yeast strains, the chemical profiles of the wines produced were significantly different. 相似文献
20.
Oxidative dehydrogenation of propane on zeolite catalysts 总被引:2,自引:0,他引:2
A. Kubacka E. Woch B. Sulikowski R. X. Valenzuela V. Corts Corbern 《Catalysis Today》2000,61(1-4):343-352
Oxidative dehydrogenation of propane has been studied on zeolite Na-Y, stabilized zeolite Y (USY) and ZSM-5. The supports with the faujasite structure were modified with boron, gallium and indium oxides and Ca, Mg, Sn, and Sb cations. The samples containing simultaneously In2O3 and Ga2O3 in the USY support were compared. A detailed analysis of the zeolite catalysts performance in the title reaction has been carried out. 相似文献