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1.
The Ozone Monitoring Instrument (OMI) operates onboard the National Aeronautics and Space Administration's Earth Observing System Aura satellite, which was launched in July 2004. Like its sister spacecraft Terra and Aqua, Aura's capabilities include direct broadcast (DB), i.e., the ability to broadcast data at the same time as they are being measured and stored in the spacecraft's memory for later transmission to Earth. The Finnish Meteorological Institute's Satellite Data Centre at Sodankyla/spl uml/ in Finnish Lapland is exploiting this capability to receive OMI data while Aura is in sight of the receiver, which enables nearly immediate production of OMI data products for a region that includes a large part of Europe, stretching from the North Pole to the Italian Alps. The current OMI Very Fast Delivery (VFD) products include maps of surface UV-B, ozone columns, and cloud coverage.  相似文献   
2.
Computing geometric properties of images represented by linear quadtrees   总被引:2,自引:0,他引:2  
The region quadtree is a hierarchical data structure that finds use in applications such as image processing, computer graphics, pattern recognition, robotics, and cartography. In order to save space, a number of pointerless quadtree representations (termed linear quadtrees) have been proposed. One representation maintains the nodes in a list ordered according to a preorder traversal of the quadtree. Using such an image representation and a graph definition of a quadtree, a general algorithm to compute geometric image properties such as the perimeter, the Euler number, and the connected components of an image is developed and analyzed. The algorithm differs from the conventional approaches to images represented by quadtrees in that it does not make use of neighbor finding methods that require the location of a nearest common ancestor. Instead, it makes use of a staircase-like data structure to represent the blocks that have been already processed. The worst-case execution time of the algorithm, when used to compute the perimeter, is proportional to the number of leaf nodes in the quadtree, which is optimal. For an image of size 2n × 2n, the perimeter algorithm requires only four arrays of 2n positions each for working storage. This makes it well suited to processing linear quadtrees residing in secondary storage. Implementation experience has confirmed its superiority to existing approaches to computing geometric properties for images represented by quadtrees.  相似文献   
3.
In transitioning to a renewable material-based bio economy, growing public and industry interest is apparent for using wooden multistory construction (WMC) as a sustainable urban housing solution in Europe, but its business implications are not well understood. In our study, we evaluate, which internal and external factors of competitiveness are shaping the future of WMC, especially in the context of Finland and Sweden. Based on a multi-level perspective of socio-technical transitions, we conducted a three-stage dissensus-based Delphi study. The identified internal and external factors affecting the future competitiveness of the WMC business emphasize the importance of skilled architects and builders and the role of standardized building systems. Based on our results, the key aspects influencing the future competitiveness of WMC in the region are related to the development of technical infrastructure and project-based business networks, while additional changes in regulatory framework are perceived as less important. We conclude that towards 2030, the strong cognitive rules founded in the concrete-based building culture in these countries is likely to inhibit the dynamics of the socio-technical regime level. A change is also needed in the WMC business culture towards more open cross-sectoral collaboration and new business networks between different-sized players.  相似文献   
4.
The widespread use of immunosuppressive therapy and antimicrobial agents as well as novel probiotics without a long history of safe use has increased requirements for safety assessment of probiotic lactobacilli. In this study 44 faecal, 52 blood and 15 probiotic isolates (including 3 dairy strains) of Lactobacillus were assayed for their adhesion properties to extracellular matrix proteins and mucus, hemolysis, ability to avoid the induction of respiratory burst in peripheral blood mononucleocytes (PMN) and resistance to human serum. Among tested strains adhesion to collagen, fibrinogen and mucus was isolate-specific and no statistically significant differences were obtained between faecal, blood and probiotic isolates. However, blood isolates showed a trend for higher adhesion to mucus than probiotic strains (P=0.07). Probiotic strains induced lower respiratory burst in PMN when compared to the blood isolates (P<0.05). Moreover, there was a positive correlation between adhesion to collagen and induction of respiratory burst for faecal isolates (P<0.05). In the determination of serum resistance, probiotic strains showed a trend for lower sensitivity to human serum-mediated killing when compared to the faecal isolates (P=0.07). None of the measurable virulence factors were found to be present at statistically higher level in clinical blood isolates when compared to faecal and/or probiotic isolates indicating that these factors do not cause risk when safety of probiotics is considered. However, the significance of adhesion to mucus, low induction of respiratory burst in PMN and resistance to human serum-mediated killing may need further evaluation in experimental animal models and in epidemiological data.  相似文献   
5.
We have developed assay technologies to measure hydrolyzing enzymes based on homogeneous time-resolved fluorescence quenching (TruPoint). High sensitivity was obtained using fluorescent europium chelates as labels, internally quenched by suitable quenchers and released upon enzymatic reaction. This approach allows robust and sensitive monitoring of low enzyme activities. The assay technology and the choice of donor-acceptor pairs were evaluated in three different enzymatic assays, a protease related to apoptosis, helicase involved in DNA unwinding, and phosphatase having an important role in cellular signaling cascades. All the assays produced an increasing signal, were sensitive, and had a good dynamic range. There were significant differences in optimized quenchers for each of the assays depending on the size, flexibility, and rigidity of the substrates. Also, clear differences in the energy-transfer reactions, their requirements for spectral overlapping, ionic interactions, and energy-transfer distances were found. Each of the enzymatic assays was briefly tested in a high-throughput screening environment by analyzing signal dynamics and statistical relevance as Z' factors.  相似文献   
6.
Drought is known to have an impact on the resistance of conifers to various pests, for example, by affecting resin flow in trees. Little is known, however, about the quantitative and qualitative changes in resin when trees are growing in low moisture conditions. We exposed Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings to medium and severe drought stress for two growing seasons and analyzed the monoterpenes and resin acids in the main stem wood after two years of treatment. In addition to secondary chemistry, we measured the level of nutrients in the needles and the growth response of seedlings. After the first year of treatment, drought stress did not affect the growth of seedlings, but in the second year, shoot growth was retarded, especially in Scots pine. In both conifer species, severe drought increased the concentrations of several individual monoterpenes and resin acids. Total monoterpenes and resin acids were 39 and 32% higher in severe drought-treated Scots pine seedlings than in the controls, and 35 and 45% higher in Norway spruce seedlings. In Scots pine needles, the concentrations of nitrogen and phosphorus increased, while magnesium and calcium decreased compared to controls. In Norway spruce needles, nutrient concentrations were not affected. The results suggest that drought stress substantially affects both the growth of conifers and the chemical quality of the wood. We discuss the potential trade-off in growth and defense of small conifer seedlings.  相似文献   
7.
Development of a reliable laboratory scale test for the design of industrial catalysts is crucial. In this article, different laboratory-scale tests were compared with an industrial scale CVOCs treatment. With dichloromethane (DCM) the laboratory scale test results corresponded well to the industrial scale oxidation results. However, the perchloroethylene (PCE) conversions measured in industry were always higher than what was achieved in the laboratory scale indicating that the industrial scale catalytic incinerator operating in transient conditions is highly beneficial in PCE oxidation. It was clearly shown that in order to design high-quality laboratory scale experiments, information on complete composition and total concentration of the emission is needed but also different types of catalytic tests need to be used depending on the industrial reactor. In addition, the catalysts’ performance in an industrial VOC abatement unit was examined as the oxidation efficiencies of DCM, PCE and other hydrocarbons (OHC) were compared after 3, 10 and 23 months of operation. After 23 months and 13,065 operating hours, no significant decrease in the activity of the catalysts was observed showing that the used noble metal catalysts are highly resistant towards these demanding conditions.  相似文献   
8.
Summary We present an optimal algorithm to determine whether a placement of N isothetic non-overlapping rectangles (macros) can be represented by a slicing tree, and if so, to find a representation of minimal height. A slicing is a recursive partition of the overall bounding rectangle, by straight horizontal or vertical cuts, into rectangular regions, each one containing exactly one macro. The algorithm first determines a representation of the empty space of the placement by means of maximally extended horizontal and vertical channels. A second phase then generates a maximal slicing tree (an ordered tree with unbounded degree and maximal branching, i.e., minimal height) in a top-down fashion. The complexity of each phase is O(N log N). The problem arises in steps (1) and (2) of our top-down approach to VLSI custom chip design, which consists of (1) floorplanning by slicing, (2) hierarchicial global wiring, and (3) detailed layout of macros.On leave from: Laboratory of Information Processing Science, Helsinki University of Technology, Espoo, FinlandOn leave from: Dipartimento di Elettrotecnica, Elettronica e Informatica, Università degli Studi di Trieste, Via Valerio, 10-34127 Trieste, Italy  相似文献   
9.
Ship's ballast waters transport large numbers of organisms which may become invasive in coastal regions. One option to address this problem is the use of biocides as ballast water treatment (BWT). Efficacy and environmental acceptability of three commercial active substances (the BWT biocides Peraclean® Ocean and Seakleen®, and alkylamine-based biocide Mexel® 432/336) were tested against three bacteria species, two vegetative microalgae and one zooplanktonic larva, in 10 and 30 Practical Salinity Unit (PSU) waters. In both salinities, PeraClean® Ocean was the most effective biocide against bacteria causing > 90% mortality at 20 mg/l, compared with 50 mg/l for Mexel® 432/336 and > 500 mg/l for Seakleen®. Regarding zooplankton, Seakleen® was the most effective chemical causing 90% mortality in 24 h at concentrations < 6 mg/l (LC9024 h) in both salinities, compared with 23 and 26 mg/l for Mexel® 432/336 and 370 and 480 mg/l for PeraClean® Ocean in 10 and 30 PSU, respectively. Similar pattern of efficacy was obtained for microalgae in 30 PSU: effective concentrations inducing 50% growth inhibition in 4 days were ≤ 1.6 mg/l for Seakleen®, ≤ 10.1 mg/l for Mexel® 432/336 and ≤ 30.9 mg/l for PeraClean® Ocean. Our work highlighted that treated waters displayed residual toxicity after 24 h still inducing mortality depending on the organism and biocide. However Mexel® 432/336 is the only biocide which had no impact on oyster larvae development at effective concentration. Altogether our data showed that Mexel® 432/336 was the only biocide displaying a broad spectrum efficacy in concentrations < 50 mg/l and not toxic for oyster larvae development at this concentration. However residual toxicity of treated waters for any organism should be taken into account in BWT systems utilising biocides.  相似文献   
10.
Electrochemical removal of dissolved oxygen from water   总被引:4,自引:0,他引:4  
A new electrochemical method of oxygen removal has been developed in which oxygen-rich water flows through the three-dimensional cathode of an electrochemical cell. The cathode removes the dissolved oxygen from the water and the anode releases it as gas into the air. By this technique oxygen levels lower than 3 µmg oxygen per kilogram of water can be reached (starting level: oxygen-saturated water, 8000 µg kg–1). This result is better than that obtained by physical methods and is equal to those obtained by chemical methods. Compared with conventional methods, the advantages of the electrochemical method are high effIciency, low energy consumption and avoidance of the use of toxic deoxygenation chemicals.  相似文献   
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