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Luminescent-dye-doped-plastics are nowadays extensively used for esthetic purposes (toys, ballpoint pens, etc.). In the early 1980's, these materials were investigated to be used as sunlight concentrators in energy generation. Recent developments in fiber optic technology, beyond mere data transmission, lead us to consider the feasibility of using such materials for light intensity sensing in fiber optic sensors networks. The sensor described in this work has proved to show high linearity, reproducibility and stability, and low directivity, however it lacks high sensitivity. Further optimization of some design parameters will definitely help to improve it  相似文献   
3.
Both males and females ofRhabditis pellio release pheromones that attract the opposite sex prior to copulation. A quantitative bioassay for the female-produced pheromone was designed, based on male movement toward a pheromone source placed at one end of a 10-mm strip of bacterial material maintained on nutrient agar in a petri plate. Females produced pheromone from the age at which they attained the adult stage (3 days following hatching from the egg) and maintained a relatively constant production level until at least the ninth day of life. Similarly, males became responsive to the female pheromone by the third day and remained responsive through the ninth day, although the time required for the males to migrate toward a female pheromone source increased with increasing age. No daily rhythm of pheromone responsiveness by males or pheromone production by females was observed when the nematodes were conditioned to a 1212 h light-dark cycle.  相似文献   
4.
In this article, security challenges related to a mobile heterogeneous networking environment, and the general access patterns are discussed. A novel, unified networking architecture that enables secure heterogeneous networking, both in terms of networks and user devices is discussed. A comprehensive security framework providing a generalized authentication scheme using the Extensible Authentication Protocol (EAP) is then presented, by taking into account existing methods for secure network and device access.  相似文献   
5.
This paper discusses how data from multiple tactile sensors may be used to identify and locate one object, from among a set of known objects. We use only local information from sensors: 1) the position of contact points and 2) ranges of surface normals at the contact points. The recognition and localization process is structured as the development and pruning of a tree of consistent hypotheses about pairings between contact points and object surfaces. In this paper, we deal with polyhedral objects constrained to lie on a known plane, i.e., having three degrees of positioning freedom relative to the sensors. We illustrate the performance of the algorithm by simulation.  相似文献   
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High‐shear impellers (HSIs) are mixers used in industrial stirred tanks to incorporate powders into liquids and break down particle agglomerates. A detailed numerical study of two commercial ring‐style HSIs of laboratory scale was carried out and their performance was compared with the Rushton turbine (RT). It was found that power and pumping numbers or their ratio cannot be simply connected for properly selecting an impeller in applications where highly localized viscous dissipation is desirable. The ratio of the average viscous dissipation in the impeller swept volume to the mean in the entire volume at two constant values of power input turned out to be lower for HSIs compared to that evaluated for RT. However, at higher power input, the dimensionless average viscous dissipation in the blade swept volume was found to be similar for the HSI of two rings and the RT, corroborating the high local viscous dissipation of this HSI when operated at higher speeds.  相似文献   
8.
The effect of the dose of oyster mushroom in the diet (1.0, 2.5, and 5.0%) and of the period of application (8, 16, 28, and 52 wk) on cholesterol accumulation in blood and body organs was studied in weanling male Wistar rats fed a diet containing 0.3% cholesterol. Reduction of cholesterol in serum and body organs was found to be dependent on the amount of dietary oyster mushroom administered. A negative correlation between the mushroom dose and cholesterol level was found after 8 and 28 wk of feeding (r=-0.9821 and -0.9803, respectively; P < 0.02 for both cases). The dose of 1% oyster mushroom did not affect cholesterol levels in serum or body organs. A significant reduction of cholesterol levels was observed in serum (31-46%) and liver (25-30%) at a dose of 5% of oyster mushroom for all periods. Reduced cholesterol content in very low-density lipoproteins (VLDL) was also observed at this level. The highest dose of oyster mushroom induced a decrease in conjugated diene levels in erythrocytes and an increase in the levels of reduced glutathione in the liver and stimulated the activities of catalase and glutathione peroxidase in the liver in the final period of the experiment.  相似文献   
9.
The square root covariance Kalman filter (SRCF) and the square root covariance Kalman predictor (SRCP) are derived from a least squares viewpoint. A new systolic array architecture is presented which is suitable for implementing both forms of the filter. The systolic SRCF is found to be comparable with other architectures in the literature in terms of size, speed and processor utilization. The SRCP is faster than any comparable architecture withO(2n) timesteps between measurements.  相似文献   
10.
A chronic consumer risk assessment based on a worst-case scenario, conducted as part of the European Union review leading to Annex I inclusion for glyphosate, was evaluated and refined. An extensive database of information on the effects of processing on the levels of glyphosate residues in food is available. This database together with refined consumption data from the UK's surveys of adults and toddlers and extensive monitoring data of glyphosate residues in mainly cereal products conducted in the UK were combined to examine the potential overestimates of dietary intakes that are predicted using the current regulatory methodology developed by the Food and Agricultural Organization/World Health Organization and applied as part of the European Union regulatory process. Analysis focussed on the chronic exposure from treated cereals, the crop group contributing significantly to the dietary intake of glyphosate residues. A steep reduction of predicted intake was seen when progressively realistic measures of residues were incorporated into the models, giving a strong indication of the conservative nature of current regulatory procedures. Calculations using even the most unrefined methodology gave rise to intakes of up to 11% of the acceptable daily intake; this was reduced to 0.6% of the acceptable daily intake when justifiable refinements based on extensive monitoring data collected in the UK were made. Consumption data for processed foods abstracted from the UK Food Standard Agency's database were used to refine further the predicted dietary intakes as a result of residue reductions or concentration from processing. The current regulatory model used in the UK generally only has the potential to use a single value for consumption of a particular food. The Pesticides Safety Directorate model consistently predicted the highest intakes with the exception of intakes by adults using the supervised trials median residue and median monitoring data. This suggests that conservatism in the regulatory model exists particularly where specific processing factors cannot be applied to individual fractions of the diet.  相似文献   
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