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21.
Metallic cobalt nanoparticles were synthesized by hydrogen reduction method. Particles were coated in situ with carbon by adding ethene to reaction flow. Particles were characterized by transmission electron microscopy, energy dispersive X-ray emission, X-ray diffraction, X-ray fluorescence and BET method. The observed cobalt particle size distributions in different cobalt batches produced with unvarying reaction parameters was reproducible: The mean diameter of primary cobalt particle varied only 5% from the mean value of 76 nm in different batches. Increased carbon precursor concentration decreased mean diameter of cobalt particles to 17 nm. The produced nanoparticles were used as filler material in 0–3 type metalpolymer composites. Composite samples with varying filler loading were fabricated with mixing extrusion and injection moulding techniques. The magnetic properties of the fabricated composites were measured up to 1 GHz. In order to analyse the particle distribution in composite matrix and its effect on magnetic properties the microstructure was studied.  相似文献   
22.
In this paper, studies on steam condensation and aerosol behaviour in a heat exchanger are presented. The heat exchanger is a model of one single tube of a Passive Containment Condenser (PCC) that is used in the European Simplified Boiling Water Reactor (ESBWR). A hot carrier gas containing nitrogen and steam with Ag and CsOH particles flows through the heat exchanger. The walls of the heat exchanger are cooled with a water jacket, thus causing steam condensation and diffusiophoretic particle deposition. The amount of condensed steam is measured, as well as the temperatures, particle mass concentrations and size distributions before and after the heat exchanger. The experiments are done with different proportions of steam and nitrogen in the carrier gas. Heat and mass transfer in the system are modelled with well known engineering correlations, producing results that agree nicely with the experimental results. The diffusiophoretic particle deposition velocity is shown to be proportional to the steam condensation rate, as expected.  相似文献   
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Most approaches to human attribute and action recognition in still images are based on image representation in which multi-scale local features are pooled across scale into a single, scale-invariant encoding. Both in bag-of-words and the recently popular representations based on convolutional neural networks, local features are computed at multiple scales. However, these multi-scale convolutional features are pooled into a single scale-invariant representation. We argue that entirely scale-invariant image representations are sub-optimal and investigate approaches to scale coding within a bag of deep features framework. Our approach encodes multi-scale information explicitly during the image encoding stage. We propose two strategies to encode multi-scale information explicitly in the final image representation. We validate our two scale coding techniques on five datasets: Willow, PASCAL VOC 2010, PASCAL VOC 2012, Stanford-40 and Human Attributes (HAT-27). On all datasets, the proposed scale coding approaches outperform both the scale-invariant method and the standard deep features of the same network. Further, combining our scale coding approaches with standard deep features leads to consistent improvement over the state of the art.  相似文献   
25.
The order‐preserving pattern matching problem has gained attention in recent years. It consists in finding all substrings in the text, which have the same length and relative order as the input pattern. Typically, the text and the pattern consist of numbers. Since recent times, there has been a tendency to utilize the ability of the word RAM model to increase the efficiency of string matching algorithms. This model works on computer words, reading and processing blocks of characters at once, so that usual arithmetic and logic operations on words can be performed in one unit of time. In this paper, we present a fast order‐preserving pattern matching algorithm, which uses specialized word‐size packed string matching instructions, grounded on the single instruction multiple data instruction set architecture. We show with experimental results that the new proposed algorithm is more efficient than the previous solutions. ©2016 The Authors. Software: Practice and Experience Published by John Wiley & Sons Ltd.  相似文献   
26.
The critical velocity of rebound was determined for spherical ammonium fluorescein particles in the size range of 0.44–7.3 μm. The method was based on measurements with a variable nozzle area impactor (VNAI) and numerical simulations. A comparison to previous results with spherical silver particles obtained with the same method showed that the critical velocity was approximately two orders of magnitude higher for ammonium fluorescein than for silver at the same size range. Among the hard test materials, including steel, aluminium, molybdenum, and Tedlar, the surface material had no significant effect on the critical velocity of rebound within the accuracy of the method. On the contrary, the critical velocity was observed to be highly dependent on the obliquity of the impact at the onset of rebound. While the ratio of the maximum tangential and normal velocities was defined as a measure for the obliquity, the critical velocity was found to be more than a magnitude smaller for very oblique impacts with the velocity ratio above 9 than for close-to-normal impacts with the velocity ratio below 1.5. The results of this study can be considered as a link between the recently published critical velocity results for nanoparticles and the older results for micron-sized particles.

Copyright © 2017 American Association for Aerosol Research  相似文献   

27.
TAPISTRY is a tutored process improvement approach tailored for small enterprises. The approach was developed, used and validated in an ongoing ESSI Esprit project (No 24238), called “TAPISTRY.” The TAPISTRY project adopted a downscaled assessment model of the BOOTSTRAP assessment methodology, called BootCheck, and developed a workshop-based assessment and improvement method, to form together a process improvement approach for small-to-medium-sized enterprises. In TAPISTRY workshops the participants are tutored in self-assessment and improvement planning by software process improvement experts. The resulting TAPISTRY approach was validated through the experiments performed during the TAPISTRY project. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
28.
The ability of six probiotic bacteria to bind a common food carcinogen, aflatoxin B1, was assessed. The studied strains included Lactobacillus strains and one Bifidobacterium strain. The strains were incubated in vitro with alfatoxin B1 and the toxin residue in the supernatant was measured using high‐performance liquid chromatography. The aflatoxin‐binding capacity of the strains was found to range from 5.8 to 31.3%. The results further support the observation that a number of probiotic bacteria are able to bind specific dietary contaminants. Although the extent of binding varies depending on the bacterial strain used, the data may explain some of the antimutagenic and anticarcinogenic effects of probiotic micro‐organisms. © 2000 Society of Chemical Industry  相似文献   
29.
The effects of preparation procedures and packaging on vitamin C, dietary fibre, sugars, ash and moisture contents were studied in prepeeled packaged potatoes during two cultivation seasons. The potato cultivars Bintje, Van Gogh and Nicola were studied. Potatoes of the Nicola cultivar had the highest initial vitamin C and sugar contents. Retention of nutrient contents in packaged, prepeeled potatoes was very good after a 7-day storage period. Vitamin C contents were higher in packaged potatoes than in fresh tubers when ascorbic acid was used in the washing solution but the levels decreased during the 7-day storage period. When calcium chloride was added as well into the washing solution vitamin C contents remained high throughout the storage period. These results show that it is possible to preserve the nutritional contents of packaged potatoes over a 7-day storage period. Cooking decreased vitamin C contents by about 30% and keeping the potatoes hot for 1 h after cooking decreased vitamin C contents a further 10%. © 1998 SCI.  相似文献   
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