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61.
A new analytic approach for the performance evaluation of buffer insertion rings is proposed which overcomes the basic limitations of former analyses. Key to our analysis is that the global performance model of a buffer insertion ring is decomposed into submodels in such a way that the basic interdependence of interarrival and transmission times of the frames transmitted is taken into account. The analysis itself is relatively straightforward and yields simple and explicit results for the mean delays of the frames. For special traffic patterns, the analysis is exact, for the general case, it is approximate but its accuracy turns out to be high, as comparison with simulation results shows.  相似文献   
62.
Impinging jets are utilized in numerous applications, including nuclear waste treatment, for both the erosion of sediment beds and maintaining particulates in suspension. Pulse‐echo ultrasonic methods offer great potential for the in situ monitoring of critical mixing and settling dynamics, in concentrated dispersions. A non‐active scaled version of a Highly Active Storage Tank at Sellafield, UK, was profiled with an acoustic backscatter system under various jet firing conditions. An advanced analysis technique enabled the direct quantification of dispersion concentration changes from the converted backscatter attenuation. Hence, the erosion and mixing capability of the jets, and settling kinetics were characterized. It was found that jet operation alone provided inadequate localized mixing of eroded sediment. An additional air‐lift process operation was required to hinder the rapid re‐settling of dispersed particulates. © 2017 American Institute of Chemical Engineers AIChE J, 63: 2618–2629, 2017  相似文献   
63.
The surface plasmon resonance (SPR) of noble metals is known to improve the efficiency of various processes and devices. The photocatalytic process is the production of fuels and storage of solar photons in chemical bonds without imposing harmful threats to the environment. Photovoltaics are other devices utilizing solar energy for electrical energy. Similarly, other optoelectronic devices like photodetectors absorb photons and convert it into charges via electron–hole dissociation processes. In contrast, light‐emitting optoelectronic devices work based on the phenomenon of charge recombination to produce light. All these devices, however, have efficiency limitations, which impede the application of novel functional materials in these devices. A more direct approach is the utilization of noble metals and their complexes, which significantly enhance the efficiencies of these devices by SPR. This article highlights recent works and applications of noble metals by SPR‐enhanced photocatalysis for hydrogen evolution from water, CO2 conversion into useful compounds, and oxidation of hazardous pollutants. In addition, the plasmon‐enhancement of optoelectronic devices is summarized. Several possible mechanisms that have been previously reported in the literature are discussed in this work, with particular emphasis on different features of these mechanisms involving devices that are not highlighted and therefore need more attention.  相似文献   
64.
Wireless Personal Communications - Visible light communication (VLC) is suitable and natural candidate for vehicular communication. This paper presents the vehicle to vehicle communication system...  相似文献   
65.
The five-year survival rate of lung cancer patients is very low, mainly because most newly diagnosed patients present with locally advanced or metastatic disease. Therefore, early diagnosis is key to the successful treatment and management of lung cancer. Unfortunately, early detection methods of lung cancer are not ideal. In this brief review, we described early detection methods such as chest X-rays followed by bronchoscopy, sputum analysis followed by cytological analysis, and low-dose computed tomography (LDCT). In addition, we discussed the potential of metabolomic fingerprinting, compared to that of other biomarkers, including molecular targets, as a low-cost, high-throughput blood-based test that is both feasible and affordable for early-stage lung cancer screening of at-risk populations. Accordingly, we proposed a paradigm shift to metabolomics as an alternative to molecular and proteomic-based markers in lung cancer screening, which will enable blood-based routine testing and be accessible to those patients at the highest risk for lung cancer.  相似文献   
66.
A quadrupole mass spectrometer (MS) was used to analyse gas samples taken from human bodies with the aid of hypodermic syringe. Because of the small amount of the produced gas samples (< 1 cm3) a special gas inlet system has been developed and built allowing to transfer the gas samples into a testing volume unadulteratedly concerning size and composition. From the testing volume the gas specimen directly flows through an UHV‐needle valve into the ion source of the MS. After a careful calibration of the MS respecting to the interesting components of the gas sample a quantitative analysis can be carried out with an uncertainty of < 1 %.  相似文献   
67.
68.
Wireless Personal Communications - Underwater LED based Optical Communication has immense applications in the marine, autonomous underwater vehicle drivers and military fields. Compared with...  相似文献   
69.
The authors examined the effectiveness of motivational interviewing (MI) on club drug use and risky sex in non-treatment-seeking men who have sex with men (MSM). MSM (N = 150) were assessed and randomly assigned to 4 sessions of MI or an educational control intervention. Follow-up occurred at quarterly intervals for 1 year. Primary outcomes were days of any club drug use and number of unsafe sex acts. On average, club drug use declined during follow-up. A significant interaction effect showed that MI was associated with less club drug use during follow-up compared with education but only among participants with lower severity of drug dependence (p  相似文献   
70.
Ultrasonic treatment can disintegrate sludge, enhance microbial activity and improve sludge dewaterability at different energy inputs. To find their relationship, the three phenomena during ultrasonic treatment were investigated synchronously, and an experimental model was established to describe the process of ultrasonic sludge disintegration. Analysis results showed that the changes of sludge microbial activity and dewaterability were dependent on sludge disintegration degree during ultrasonic treatment. When sludge disintegration degree was lower than 20%, sludge flocs were disintegrated into micro-floc aggregates and the microbial activity increased over 20%. When sludge disintegration degree was over 40%, most cells were destroyed at different degree, and sludge activity decreased drastically. Only when sludge disintegration degree was 2-5%, sludge dewaterability was improved with the conditioning of FeCl(3). It was also found that the sonication with low density and long duration was more efficient than sonication with high density and short duration at the same energy input for sludge disintegration, and a transmutative power function model can be used to describe the process of ultrasonic disintegration.  相似文献   
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