This work investigates emulsion templating to synthesize hexadecane oil/geopolymer composites. In a system with hexadecane as the internal (dispersed) phase and an alkali activated continuous phase without added surfactant, adding aluminosilicate clay particles does not increase resistance against creaming or coalescence, while adding a surfactant (L35 or CTAB) stabilizes the solid-liquid interface. Infrared studies and rheological studies of the associated geopolymerization determined that the presence of the organic phase or surfactant has no significant effect on the geopolymerization kinetics, as determined by the change in time of the Si-O-T IR stretching frequency and the rheological moduli involved during the process. The stabilization of the organic template is reminiscent of Pickering emulsion even though we employ a much greater amount of inorganic material for geopolymer formation. Although the addition of surfactant has a significant effect on the behavior of the paste, the percolation of the network remains unmodified, highlighting the fact that the phenomenon is not dependent on viscosity. Finally, rheological measurements were used to obtain the mass fractal dimension of the as-made gel network, which is able to differentiate the interfacial effect between surfactant molecules with a slightly denser interphase when a cationic surfactant is used. 相似文献
Four hundred forty-six patients with Tourette Syndrome (TS) and/or their parents completed a 52-item self-report survey about vocal and motor tics, and the frequency of associated co-morbid conditions of aggression, obsessions and compulsions, attentional problems, sleep disturbance, mood disturbance, anxiety, and self-mutilative behaviours which have been frequently reported in the literature on TS. Respondents also responded to an open-ended question regarding the most disabling aspects of TS. Results were analyzed within two age groups; under 18 years of age (N = 245) and 18 years of age or older (N = 177). Tics and associated conditions were the most frequently reported disabling aspect by both age groups. Subjects under age 18, however, reported significantly more frequent problems with hyperactivity, temper control, aggressive behaviours and sleepwalking than adults with TS. 相似文献
Baker and confectioner apprentices have been included in a prospective follow-up study in the region of East Thuringia, to evaluate risk factors for the development of hand dermatitis. Starting in August 1996, the apprentices have been interviewed and examined in a standardized way right at the beginning (n=91) of their vocational training, 6 (n=79) and 12 months (n=63) later. To gain objective data, TEWL score was also assessed at 3 standardized sites on the hands. In their case histories, 3.3% (n=3) of the apprentices reported hand dermatitis. The 1st assessment after 2 to 4 weeks vocational training revealed hand eczema in 17.5% (n=16) of the individuals. At the follow-up after 6 months of training 29.1% (n=23), and after 12 month of training 27.0% (n=17), of the apprentices had hand dermatitis of mild to moderate severity. Within 6 months, the TEWL score rose significantly (p<0.001) from 11.9 g m(-2) h(-1) (-/+5.4) to 16.8 g m(-2) h(-1) (-/+9.5). After 12 months, the TEWL score was 14.9 g m(-2) h(-1) (-/+4.6). For the atopic skin diathesis (>10 points of Diepgen's atopy score), there was a significant tendency to be a predictive factor for the development of occupational hand dermatitis. TEWL score failed to correlate with the development of skin damage in our study. The same was true for respiratory atopy and metal sensitization. 相似文献
Two Canadian rapeseed oils, “Westar” and “low-linolenic”, supplied by the Canola Council were studied and compared with a
French rapeseed. The linolenic acid content of the low-linolenic variety is about 3%. This drop in the C18∶3 is completely
compensated for by an increase in the C18∶2. Seventy-two percent of the triglycerides with at least one linolenic chain disappeared.
A strong increase in the OOL and OLL was observed. The room-odor tests showed that the “low-linolenic” had a significantly
higher odor score than the French rapeseed and the “Westar”, both of these being very similar. A fruity odor dominated in
the “low-linolenic”, and the fishy painty odors were particularly reduced. 相似文献
In this perfusion magnetic resonance imaging study, the performances of different pseudo-continuous arterial spin labeling (PCASL) sequences were compared: two-dimensional (2D) single-shot readout with simultaneous multislice (SMS), 2D single-shot echo-planar imaging (EPI) and multishot three-dimensional (3D) gradient and spin echo (GRASE) sequences combined with a background-suppression (BS) module.
Materials and methods
Whole-brain PCASL images were acquired from seven healthy volunteers. The performance of each protocol was evaluated by extracting regional cerebral blood flow (rCBF) measures using an inline morphometric segmentation prototype. Image data postprocessing and subsequent statistical analyses enabled comparisons at the regional and sub-regional levels.
Results
The main findings were as follows: (i) Mean global CBF obtained across methods was were highly correlated, and these correlations were significantly higher among the same readout sequences. (ii) Temporal signal-to-noise ratio and gray-matter-to-white-matter CBF ratio were found to be equivalent for all 2D variants but lower than those of 3D-GRASE.
Discussion
Our study demonstrates that the accelerated SMS readout can provide increased acquisition efficiency and/or a higher temporal resolution than conventional 2D and 3D readout sequences. Among all of the methods, 3D-GRASE showed the lowest variability in CBF measurements and thus highest robustness against noise.
We introduce a new, online, stroke-based recognition system for hand-drawn diagrams which belong to a group of documents with an explicit structure obvious to humans but only loosely defined from the machine point of view. We propose a model for recognition by selection of symbol candidates, based on evaluation of relations between candidates using a set of predicates. It is suitable for simpler structures where the relations are explicitly given by symbols, arrows in the case of diagrams. Knowledge of a specific diagram domain is used—the two domains are flowcharts and finite automata. Although the individual pipeline steps are tailored for these, the system can readily be adapted for other domains. Our entire diagram recognition pipeline is outlined. Its core parts are text/non-text separation, symbol segmentation, their classification and structural analysis. Individual parts have been published by the authors previously and so are described briefly and referenced. Thorough evaluation on benchmark databases shows the accuracy of the system reaches the state of the art and is ready for practical use. The paper brings several contributions: (a) the entire system and its state-of-the-art performance; (b) the methodology exploring document structure when it is loosely defined; (c) the thorough experimental evaluation; (d) the new annotated database for online sketched flowcharts and finite automata diagrams. 相似文献
The circular harmonic filter contains only one component of the image. Its discrimination capability has been questionable. The geometrical approach of multiple circular harmonic filters uses relative locations of the correlation peaks as the rotation-, shift-, and intensity-invariant features for pattern recognition. Each feature depends on the entire image. This approach has a good discrimination capability. Optical real-time implementation of the on-axis continuous phase-only circular harmonic filters by the use of a commercial liquid-crystal television is shown. A harmonic analysis shows that the phase-mostly filter can tolerate coupled amplitude modulation at the acceptable expense of the output signal-to-noise ratio. An optical experiment of the geometrical approach of multiple circular harmonic filters for a multiple-image input is described. The cross-correlation peaks between the individual filters and the clutter are eliminated, because they are not in good locations. 相似文献
This work aims at demonstrating the interest of a new methodology for the design and optimization of composite materials and structures. Coupling reliability methods and homogenization techniques allow the consideration of probabilistic design variables at different scales. The main advantage of such an original micromechanics-based approach is to extend the scope of solutions for engineering composite materials to reach or to respect a given reliability level. This approach is illustrated on a civil engineering case including reinforced fiber composites. Modifications of microstructural components properties, manufacturing process, and geometry are investigated to provide new alternatives for design and guidelines for quality control. 相似文献