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1.
The effect of water on the selective catalytic reduction (SCR) of nitric oxide with ammonia over alumina supported with 2–15 wt.-% manganese oxide was investigated in the temperature range 385–600 K, with the emphasis on the low side of this temperature window. Studies on the effect of 1–5 vol.-% water vapour on the SCR reaction rate and selectivity were combined with TPD experiments to reveal the influence of water on the adsorption of the single SCR reactants. It turned out that the activity decrease due to water addition can be divided into a reversible inhibition and an irreversible deactivation. Inhibition is caused by molecular adsorption of water. TPD studies showed that water can adsorb competitively with both ammonia and nitric oxide. Additional kinetic experiments revealed that adsorbed ammonia is present in excess on the catalyst surface, even in the presence of water. Reduced nitric oxide adsorption is responsible for the observed reversible decrease in the reaction rate; the fractional reaction order changes from 0.79 in the absence of water to 1.07 in its presence. Deactivation is probably due to the dissociative adsorption of water, resulting in the formation of additional surface hydroxyls. As the amount of surface hydroxyls formed is limited to a saturation level, the deactivating effect on the catalyst is limited too. The additional hydroxyls condense and desorb in the temperature range 525–775 K, resulting in a lower degree of deactivation at higher temperature. A high temperature treatment at 775 K results in a complete regeneration. The amount of surface hydroxyls formed per unit surface area decreases at increasing MnOx-loading. The selectivity to the production of nitrogen is enhanced significantly by the presence of gas phase water.  相似文献   
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This laboratory study examined the possibility of using a car seat instrumented with a tactile display to communicate directional information to a driver. A car seat fitted with an 8 × 8 matrix of vibrators embedded in the seat pan was used to code eight different directions. Localization response time and angular accuracy were examined as a function of stimulus direction, presence of a tactile attention cue, temporal pattern, stimulus layout, age, and gender. The mean absolute angular error was 23°, and both localization accuracy and response times were superior for the back left, backward, and back right directions. Of the various temporal pattern/attention cue combinations examined, results favored the relatively fast patterns consisting of vibration bursts of 125 or 250 ms without a centrally located attention cue over 500 ms bursts that were preceded by an attention cue. Observed age and gender effects were relatively modest, suggesting that using tactile cueing to communicate direction is effective across a wide range of users. In addition, the tactile stimulus was detected by more than 90% of the participants under surprise trial conditions. Overall, these results indicate that the tactile chair provides a promising and robust method of providing directional information.  相似文献   
4.
The modal μ-calculus is a very expressive temporal logic. In particular, logics such as LTL, CTL and CTL* can be translated into the modal μ-calculus, although existing translations of LTL and CTL* are at least exponential in size. We show that an existing simple first-order extension of the modal μ-calculus allows for a linear translation from LTL. Furthermore, we show that solving the translated formulae is as efficient as the best known methods to solve LTL formulae directly.  相似文献   
5.
We used 2‐D DIGE to analyze the early response of NB‐4 cells, a human promyelotic leukemia cell line, exposed to lethal toxin from Bacillus anthracis at the proteome level. After a 2 h exposure, cells were still viable and 43% of spots (n = 1042) showed a significant change in protein level. We identified 59 spots whose expression had changed significantly, and these reflected cytoskeleton damage, mitochondrial lysis and endoplasmic reticulum stress. Actin filament assembly was disrupted as evidenced by an increase in both actin subunits and phosphorylated cofilin, whilst levels of tropomyosin, tropomodulin and actin related protein 2/3 complex subunit decreased. Lower levels of ATP synthase subunits and mitochondrial inner membrane protein were identified as markers of mitochondrial lysis. Levels of various stress response proteins rose and, uniquely, levels of Ca2+ binding proteins such as translationally controlled tumor protein rose and hippocalcin‐like protein 1 decreased. This response may have mitigated effects brought about by mitochondrial lysis and endoplasmic reticulum stress, and delayed or prevented apoptosis in NB‐4 cells. These results resemble findings of similar proteomics studies in murine macrophages, although quantitative differences were observed.  相似文献   
6.
Similar to other countries, also in the Netherlands young male drivers (ages between 18 and 24 years) are overrepresented in crashes during weekend nights, thereby fatally injuring one or more of their passengers. This overrepresentation may be due to two contributing factors: (a) a higher exposure-to-risk because of dangerous trip condition, and (b) a higher tendency to take risks. Studies on these factors, mostly carried out in jurisdictions where youngsters are licensed at an earlier age than in Europe, suggest a strong –often negative– influence from peer-aged passengers. Given that in adolescence susceptibility to peer pressure reduces with age, these findings may not be applicable to late licensing countries, such as in Europe. In the Netherlands –a late licensing country– youngsters are licensed after the age of 18 years, followed by a 5 year probation period with a legal alcohol limit of 0.2 g/L. Further, designated driver schemes are in place since 2001, alcohol limits are enforced by random breath testing schemes, and no passenger and night time restrictions are in force. Against this background, we examined the incidence of dangerous trip conditions and risk taking among young male drivers and compared those with a reference group with a low passenger fatality rate. To that end, data on trip conditions and risk behavior were obtained from a data base on 18,608 randomly selected drivers during weekend nights in 2010, between 22:00 and 06:00. This data base held information for each randomly selected on breath alcohol concentration (BAC), license status, driver characteristics (age and gender), number of passengers, time of night, and level of urbanization. Binary logistic regression analysis confirmed the overrepresentation of young male drivers in traffic, carrying more frequently passengers than the reference group, especially after midnight. Urbanization level was not a modifying factor, but ‘time of night’ was, with riskier conditions after midnight in terms of: (a) a higher young male driver presence, (b) young male drivers carrying more frequently multiple passengers and (c) a higher prevalence of illegal BACs. After midnight, no evidence was found for a protective effect of the presence of one passenger on alcohol use. Of the young male drivers, 5% were over the legal limit and 3 in 5 young males who were over the limit carried passengers. However, the indicative result that young male drivers with multiple passengers were less likely to have been drinking than solo drivers or drivers with just one passenger, is suggestive of a protective effect of multiple passengers. These results may guide preventive strategies, including police enforcement and designated driver programmes.  相似文献   
7.
Mutations in the Von Hippel–Lindau (VHL) gene are the driving force in many forms of clear cell renal cell carcinoma (ccRCC) and promote hypoxia-inducible factor (HIF)-dependent tumor proliferation, metastasis and angiogenesis. Despite the progress that has already been made, ccRCC generally remain resistant to conventional therapies and ccRCC patients suffer from metastasis and acquired resistance, highlighting the need for novel therapeutic options. Cysteinyl leukotriene receptor 1 (CysLTR1) antagonists, like zafirlukast, are administered in bronchial asthma to control eicosanoid signaling. Intriguingly, long-term use of zafirlukast decreases cancer risk and leukotriene receptor antagonists inhibit tumor growth, but the mechanisms still remain unexplored. Therefore, we aim to understand the mechanisms of zafirlukast-mediated cell death in ccRCC cells. We show that zafirlukast induces VHL-dependent and TNFα-independent non-apoptotic and non-necroptotic cell death in ccRCC cells. Cell death triggered by zafirlukast could be rescued with antioxidants and the PARP-1 inhibitor Olaparib, and additionally relies on HIF-2α. Finally, MG-132-mediated proteasome inhibition sensitized VHL wild-type cells to zafirlukast-induced cell death and inhibition of HIF-2α rescued zafirlukast- and MG-132-triggered cell death. Together, these results highlight the importance of VHL, HIF and proteasomal degradation in zafirlukast-induced oxidative cell death with potentially novel therapeutic implications for ccRCC.  相似文献   
8.
The hydrogen hype of the last decade has passed and it is now seemingly substituted by the electric vehicle hype. A technological hype can have both positive as well as negative consequences. On the one hand it attracts sponsors for technology development but on the other hand the high expectations might result in disappointment and subsequent withdrawal of the sponsors. In this paper I ask the question to what extent the car industry has created the hype and how it has done so. The industry’s role is studied through their prototyping activities and accompanying statements on market entry. I conclude that the car industry has indeed inflated the hype, especially through its public statements on market release after the turn of the millennium. Furthermore, it can be concluded that the industry has shown a double repertoire of both highly optimistic and more modest statements. It is possible that statements are used deliberately to serve the industry’s interests whenever needed. Without neglecting the positive influence of technological hype on public policy and private funding for R&D efforts, more modest promises could serve the development of sustainable mobility better. For policy makers the challenge is to remain open to different options instead of following hypes and disappointments as they come and go.  相似文献   
9.
An experimental study of flow-induced failure of cable-tied blocks is presented. The particular failure mechanism studied is overturning and rolling up of the leading edge of a cable-tied block mat. Individual blocks were investigated also. The block size, flow depth, and block (mat) protrusion above the surrounding bed were systematically varied. The results are presented in terms of the critical dimensionless shear stress θc for block (mat) failure. A relationship between θc, block size and block protrusion, and flow depth is given.  相似文献   
10.
Zusammenfassung Viele Verbraucher halten die gewöhnlichen, nur mit Essigsäure hergestellten Heringsmarinaden für zu Sauer. Man fügt darum oftmals den Marinaden Stoffe zu, die den ausgeprägt sauren Geschmack verdecken. Dafür werden z. B. Süßstoffe, Zucker sowie Stoffe verwendet, welche Acetaldehyd binden. Diese letzteren Stoffe werden bisweilen zugefügt, weil einige Essigsäuresorten Spuren von Acetaldehyd enthalten. Diese Spuren können den Geschmack der Marinaden nachteilig beeinflussen.Mit Hilfe von Milchsäure und Essigsäure können Marinaden hergestellt werden. Die auf diese Weise bereiteten Marinaden besitzen einen weniger Sauren Geschmack als die mit Essigsäure hergestellten Produkte. Die Meinung der Verbraucher ist jedoch unterschiedlich (Traditionsgründe?).In der Vergangenheit wurde die Verwendung von Milchsäure von verschiedenen Wissenschaftlern wegen der geringeren Pufferwirkung der Milchsäure abgelehnt. Dies ist objektiv richtig, da der End-pH-Wert für die Haltbarkeit mitbestimmend ist. Wenn man aber etwas mehr Milchsäure zugibt, als man auf Grund des Anfang-pH-Wertes des Garbades annehmen Sollte, können auf brauchbare Weise mit Hilfe von Milchsäure Marinaden hergestellt werden.
Summary Many consumers feel that the usual herring marinades produced with acetic acid only are too Sour. Therefore substances are often added to the marinades in order to conceal the destinct Sour flavour. For this purpose sweeting substances like sugar and substances which bind acetaldehyde are used. The latter ones are Sometimes added, because Some acetic acid varieties contain traces of acetaldehyde. These traces can influence the flavour of marinades negatively.By application of lactic and acetic acid marinades can be produced. The marinades produced this way do have a less Sour flavour than those produced with acetic acid. The consumers' point of view, however, is different.In the past the application of lactic acid was rejected by Several scientists because of its low buffer capacity. Considered objectively this is right because the pH-value at the end does have Some importance on the keeping quality. But if a little bit more lactic acid is added or. account of the Starting pH-value, marinades can be produced with lactic acid in a practicable manner.


Institut für Fischereiprodukte TNO.  相似文献   
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