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31.
A theoretical and numerical investigation is devised for resonant light scattering of an off-axis normally incident Gaussian beam by two parallel nonabsorbing cylinders based on the related beam theory developed in J. Opt. Soc. Am. A 14, 640 (1997). By varying the half-beam width, we show that the multireflection process between the two scatterers can be minimized. Moreover, the study is an attempt to understand the underlying physics present in the process of resonance excitation by evanescent wave coupling.  相似文献   
32.
A new procedure to mitigate the environmental impacts and reduce the cost of disposal of oil slurry is present in this paper. Waste from the petroleum industry has a high environmental impact. Systems for oil–water separation have been used to mitigate the contamination potential of these types of effluents. At the outlet of these systems, the oil is skimmed-off the surface, while the slurry is removed from the base. Due to the high concentration of contaminants, the disposal of this slurry is an environmentally hazardous practice. Usually this type of waste is disposed of in tanks or landfills after removal from the industrial plant. Basically, the proposed procedure utilizes drying beds with geotextile filters to both reduce the water content in the slurry and obtain a less contaminated effluent. Laboratory tests were carried out to simulate the drying system. Four types of filters were analyzed: two non-woven geotextiles, one woven geotextile, and a sand filter.  相似文献   
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The use of black & white (B&W) air photographs for the production of historic land cover maps can be done by image classification, using additional texture features. In this paper we evaluate the importance of a number of parameters in the image classification process based on texture, such as the window size, angle and distance used to produce the texture features, the number of features used, the image quantization level and its spatial resolution. The evaluation was performed using five photographs from the 1950s. The influence of the classification method, the number of classes searched for in the images and the post‐processing tasks were also investigated. The effect of each of these parameters for the classification accuracy was evaluated by cross‐validation. The selection of the best parameters was performed based on the validation results, and also on the computation load involved for each case and the end user requirements. The final classification results were good (average accuracy of 85.7%, k = 0.809) and the method has proven to be useful for the production of historic land cover maps from B&W air photographs.  相似文献   
36.
Current research on dental implants has mainly focused on the influence of surface roughness on the rate of osseointegration, while studies on the development of surfaces to also improve the interaction of peri-implant soft tissues are lacking. To this end, the first purpose of this study was to evaluate the response of human gingival fibroblasts (hGDFs) to titanium implant discs (Implacil De Bortoli, Brazil) having different micro and nano-topography: machined (Ti-M) versus sandblasted/double-etched (Ti-S). The secondary aim was to investigate the effect of the macrogeometry of the discs on cells: linear-like (Ti-L) versus wave-like (Ti-W) surfaces. The atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis showed that the Ti-S surfaces were characterized by a significantly higher micro and nano roughness and showed the 3D macrotopography of Ti-L and Ti-W surfaces. For in vitro analyses, the hGDFs were seeded into titanium discs and analyzed at 1, 3, and 5 days for adhesion and morphology (SEM) viability and proliferation (Cck-8 and MTT assays). The results showed that all tested surfaces were not cytotoxic for the hGDFs, rather the nano-micro and macro topography favored their proliferation in a time-dependent manner. Especially, at 3 and 5 days, the number of cells on Ti-L was higher than on other surfaces, including Ti-W surfaces. In conclusion, although further studies are needed, our in vitro data proved that the use of implant discs with Ti-S surfaces promotes the adhesion and proliferation of gingival fibroblasts, suggesting their use for in vivo applications.  相似文献   
37.
The objective of the study was to evaluate the hygienic conditions and practices of commercial foods of plant origin in establishments and street marketed by street vendors in cities in the State of Rio de Janeiro, Brazil. Forty different sales points were evaluated (establishments that prepared and sold fruit juices and street vendors that commercialized fresh coconut water, sugarcane juice and orange juice) using a questionnaire with 12 items, divided into three blocks (salesmen/handlers, operations, installations). The results indicated that the activities related to the commerce of fruit beverages in the cities of São Gonçalo and Rio de Janeiro required the elaboration of a set of actions by the Sanitary Vigilance Agency in order to improve the hygienic and sanitary level and minimize health risk to consumers. Important requirements in the legislation relevant to this type of food are still not followed; adequate packaging and storage of the raw material, obtaining the raw material from registered suppliers, hygiene of the handlers and adequate management of wastes produced during the activities in question are amongst the main items deserving attention.  相似文献   
38.
The AROUND Architecture for Dynamic Location-Based Services   总被引:1,自引:0,他引:1  
This paper presents a generic concept of location-based service as an abstraction for supporting the association between computational resources and location. The objective is to extend the advantages of service-based architectures to the development of location-based systems, thus providing a more open and extensible alternative to the vertical approaches typically used in this type of system. The novel AROUND architecture is proposed as an approach for supporting location-based services in the Internet environment. AROUND provides a service location infrastructure that allows applications to select services that are specifically associated with their current location. The architecture includes a flexible scope model that defines the association between services and location, and a service location infrastructure organised by spatial criteria and optimised for location-based queries. Based on a prototype implementation of this architecture, we have developed two case studies that illustrate the use of this approach for developing location-based systems. The overall results provide a valuable insight into the applicability of the architecture, and suggest that this model of location-based services can provide a useful approach for the development of a wide range of location-based applications.  相似文献   
39.
ABSTRACT: Hypercholesterolemic hamsters were fed for 4 wk on diets rich in saturated fatty acids and cholesterol, differing only in protein source (20 %): casein (control group, HC), whole cowpea seed (HWS), and cowpea protein isolate (HPI). Hamsters fed on HWS and HPI presented significant reductions in plasma total cholesterol and non‐HDL cholesterol. HPI and HC presented similar protein digestibility, which were significantly higher than that of HWS. Animals fed on HWS presented significantly higher levels of bile acids and cholesterol in feces than did the animals fed on casein or HPI diets. Histological analyses of the liver showed that HC diet resulted in steatosis widely distributed throughout the hepatic lobule, while HWS and HPI diets promoted reductions in liver steatosis. The effectiveness of HWS for modulating lipid metabolism was greater than that of HPI, as measured by plasma cholesterol reduction and liver steatosis.  相似文献   
40.
A multilayer solid state device which is both an active target and tracking detector is proposed for an electronic experiment investigating the so-called anomalons and studying their production mechanism, interaction cross-section and lifetime. The experimental method is based on triggering the reinteractions in two targets of heavy fragments, originated in a production target by a relativistic ion beam. This method greatly increases the sensitivity to the anomalon's effect when compared to other proposed electronic experiments. Solid state devices seem to provide a resolving technique for the study of these short-lived states among high-multiplicity final systems.  相似文献   
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