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41.
Influence of pencil lead hardness on voltammetric response of graphite reinforcement carbon electrodes 总被引:1,自引:0,他引:1
Paulo Henrique Campos Prado Tavares Paulo Jorge Sanches Barbeira 《Journal of Applied Electrochemistry》2008,38(6):827-832
This work studied the voltammetric response of graphite reinforcement electrodes made of different pencil lead hardness. The
studies showed that harder graphite leads, regardless of their manufacturer, are more appropriate as electrode material for
voltammetric purposes due to their higher peak currents, increasing sensitivity and reproducibility, with ΔEp closer to the theoretical value for a reversible system. 相似文献
42.
Rudolf Felix 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2008,12(2):129-135
Real world applications of a decision model of relationships between goals based on fuzzy relations are presented. In contrast
to other approaches the relationships between decision goals or criteria for each decision situation are represented and calculated
explicitly. The application fields are decision making for financial services and optimization of production sequences in
car manufacturing. 相似文献
43.
Jesús Canales-Vázquez Juan Carlos Ruiz-Morales David Marrero-López Juan Peña-Martínez Pedro Núñez Pedro Gómez-Romero 《Journal of power sources》2007
In the work presented herein, the potential use of La4Sr8Ti12−xFexO38−δ (LSTF) materials as electrodes for a new concept of solid oxide fuel cells, symmetrical fuel cells (SFCs), is considered. Such fuel cells use simultaneously the same material as anode and cathode, which notably simplifies the assembly and further maintenance of the cells. Therefore, we search for materials showing high conductivity in a wide range of oxygen partial pressures in addition to certain degree of catalytic activity for the oxidation of the fuel and reduction of the oxidant, respectively. The preliminary electrochemical experiments performed reveal that the overall conductivity increases notably upon Fe substitution, being the main contribution electronic n-type. The fuel cell tests indicate that LSTF composites with YSZ and CeO2 perform reasonably well under H2 conditions, although the performance in methane is rather modest and require further optimisation. 相似文献
44.
The influence of different alkali halides (LiF, LiCl. LiBr, NaF, NaCl, NaBr, KF, KCl and KBr) on α-chymotrypsin-catalysed plastein synthesis has been studied in aqueous medium at different substrate concentrations. The results showed an enhancing effect on the plastein synthesis enzyme action by the presence of salts, proportional to salt concentration, which was decreased when the substrate concentration was increased. Additionally, these facts allowed the ions to be classified as a function of their activation power (F? > Cl? > Br?: K+ > Na+ > Li+), which was in agreement with the interpretation of the Hofmeister lyotropic series. The influence of the several phenomena produced by the presence of salts in the plastein reaction, such as, salt-substrate interactions and water activity, as well as the presence of deactivated enzyme was also analysed. The obtained results showed that the substrate concentration is the most important factor, and the activating effect of salts could be simultaneously involved with both a structural change on the substrate conformation and a reduction of water activity into the reaction media, enhancing the catalytic capability of the α-chymotrypsin towards a peptide synthesis action. 相似文献
45.
46.
Víctor Osma-Ruiz Juan I. Godino-Llorente Pedro Gómez-Vilda 《Pattern recognition》2007,40(3):1078-1090
The present paper describes a new algorithm to calculate the watershed transform through rain simulation of greyscale digital images by means of pixel arrowing. The efficiency of this method is based on limiting the necessary neighbouring operations to compute the transform to the outmost, and in the total number of scannings performed over the whole image. The experiments demonstrate that the proposed algorithm is able to significantly reduce the running time of the fastest known algorithm without involving any loss of efficiency. 相似文献
47.
P. B. Malafaya A. J. Pedro A. Peterbauer C. Gabriel H. Redl R. L. Reis 《Journal of materials science. Materials in medicine》2006,17(7):675-675
In the XML file of the original article, H. Redl’s affiliation is incorrect. It is listed correctly in both the paper and
PDF versions of the article, and can be found below:
The online version of the original article can be found at 相似文献
48.
Robert Leeb Felix Lee Claudia Keinrath Reinhold Scherer Horst Bischof Gert Pfurtscheller 《IEEE transactions on neural systems and rehabilitation engineering》2007,15(4):473-482
The step away from a synchronized or cue-based brain-computer interface (BCI) and from laboratory conditions towards real world applications is very important and crucial in BCI research. This work shows that ten naive subjects can be trained in a synchronous paradigm within three sessions to navigate freely through a virtual apartment, whereby at every junction the subjects could decide by their own, how they wanted to explore the virtual environment (VE). This virtual apartment was designed similar to a real world application, with a goal-oriented task, a high mental workload, and a variable decision period for the subject. All subjects were able to perform long and stable motor imagery over a minimum time of 2 s. Using only three electroencephalogram (EEG) channels to analyze these imaginations, we were able to convert them into navigation commands. Additionally, it could be demonstrated that motivation is a very crucial factor in BCI research; motivated subjects perform much better than unmotivated ones. 相似文献
49.
AIM: The quality of segmentation and three-dimensional reconstruction of anatomical structures in tomographic slices is often impaired by disturbances due to partial volume effects (PVE). The potential for artefact reduction by use of the morphological image processing operators (MO) erosion and dilation is investigated. DESIGN: The CT examinations of 31 patients with pathological alterations in lung or brain were segmented using automatic region growing and the MO were applied in a different number of iterations. The processed regions were 3D-reconstructed (shaded surface display, MIP, volume rendering) and the occurrence of PVE-related artefacts using the signal-to-background ratio (SBR) prior to and after MO application was compared. RESULTS: For all patients under review, the artefacts caused by PVE were significantly reduced by erosion (lung: mean SBRpre = 1.67, SBRpost = 4.83; brain: SBRpre = 1.06, SBRpost = 1.29) even with only a small number of iterations. Region dilation was applied to integrate further structures (e.g. at tumor borders) into a configurable neighbourhood for segmentation and quantitative analysis. CONCLUSIONS: The MO represent an efficient approach for the reduction of PVE artefacts in 3D-CT reconstructions and allow optimized visualization of individual objects. 相似文献
50.
Carmen Martín-Hernández Manuela Juárez Mercedes Ramos Pedro Martín-Alvarez 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1990,190(4):325-330
Summary Physicochemical and organoleptic properties were studied in two batches of four different types of goat's milk cheese: fresh, washed curd, soft with surface flora, and Majorero, frozen for four months prior to ripening and/or chilled storage. Frozen storage did not produce significant changes in the rheological or sensory characteristics of the cheeses, except in the case of fresh cheese, the textural characteristics of which were adversely affected. The level of proteolysis, estimated from the amino-acid nitrogen, was higher in the pre-frozen washed curd, soft with surface flora, and Majorero cheeses. The level of lipolysis was comparable, except in the soft cheese with surface flora, which presented higher levels of free fatty acids when stored frozen before ripening.
Einfluß des Gefrierens und der Gefrierlagerung auf die physikalisch-chemischen und organoleptischen Eigenschaften von vier Ziegenkäsen
Zusammenfassung Aus Ziegenmilch wurden jeweils zwei Chargen von vier spanischen Käsesorten hergestellt: Frischkäse, gewaschene Käsemasse, Weichkäse mit Oberflächenflora und Majorero -Käse. Von jeder Charge wurde die Hälfte gefroren gelagert und erst nach vier Monaten auf die übliche Weise gereift und/oder gekühlt aufbewahrt. Die physikalisch-chemischen und organoleptischen Eigenschaften wurden danach untersucht. Im Vergleich mit Käsen, die nicht gefroren gewesen waren, ergaben sich keine wesentlichen Unterschiede in den rheologischen und sensorischen Eigenschaften, mit Ausnahme bei den Frischkäsen, bei dem sich die Textur durch die Aufbewahrung in gefrorenem Zustand verschlechtert hatte. Der Gehalt an freien Aminosäuren, ein Maß für die Proteolyse, war höher in der gewaschenen Käsemasse, in dem Weichkäse mit Oberflächenflora und in dem Majorero-Käse, die vier Monate gefroren gewesen waren. Durch die Gefrierlagerung hatte sich der Fettabbau nicht verändert, mit Ausnahme bei dem Käse mit Oberflächenflora, bei dem der Gehalt an freien Fettsäuren erhöht war im Vergleich mit dem Käse, der nicht vier Monate gefriergelagert worden war.相似文献