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861.
A two-port polarization-independent tunable spectral slicing filter at the 1530?nm wavelength regime is presented. The design utilizes an asymmetric interferometer with a sparse index grating along its arms. The sparse grating makes it possible to select equally spaced frequency channels from an incident WDM signal and to place nulls between them to coincide with the signal comb frequency. The number of selected channels and nulls between them depends on the number of coupling regions used in the sparse grating. The free spectral range depends on the spacing between the coupling regions. The Z-transform method is used to synthesize the filter and determine the spectral response. The operation of a device with six coupling regions is demonstrated, and good agreement with theoretical predictions is obtained. A 3?dB bandwidth of ~1?nm and thermal tuning over a range of ~13?nm are measured. 相似文献
862.
Analysis of volatile components of Petite Arvine wine 总被引:3,自引:0,他引:3
Claudia Fretz Susanne Känel Jean-Luc Luisier Renato Amadò 《European Food Research and Technology》2005,221(3-4):504-510
Petite Arvine is a white grape variety that grows exclusively in the canton of Valais in Switzerland and is used to produce a typical regional wine. In order to elucidate the nature of the flavour compounds that contribute to the characteristic aroma of this wine, the organic extracts were analysed by gas chromatography and olfactometry. The olfactometrically detected zones were further compared with the odour of extracts of vegetal material. 3-Mercaptohexanol, -ionone and other compounds were identified as main contributors to the characteristic aroma of Petite Arvine wine. 相似文献
863.
Giulio Bartoli Dania Marabissi Renato Pucci Luca Simone Ronga 《Journal of Signal Processing Systems》2017,89(1):133-143
The demand for pervasive wireless access and high data rate services are expected to grow significantly in the near future. In this context, the deployment of Heterogeneous Networks (HetNets) will enable important capabilities, such as high data rates and traffic offloading, providing dedicated capacity to homes, enterprises, and urban hotspots. Despite HetNet technology will be beneficial for future wireless systems in many ways, the massive cells diffusion has as a consequence an exponential increase of the backhaul traffic that can create congestion and collapse the backhaul network. Virtualization of networks and radio access allows the implementation of complex and efficient decisional processes for radio and network resource optimization, but the interaction between lower and upper layers during resource allocation decisions is still mostly unexplored. In this paper we propose an artificial intelligence based approach, with two interdependent decisional cores exchanging information, one aware of physical layer aspects and the other controlling pure network resources. The two iterative procedures aim at jointly optimizing the distribution of the traffic in the backhaul network and the users cell association, with the goals of minimizing the unsatisfied users data rate requests and minimizing the energy consumption reducing the number of activated cells, respectively. 相似文献
864.
Thiago L. T. da Silveira Raíza S. Oliveira Fábio M. Bayer Renato J. Cintra Arjuna Madanayake 《Signal, Image and Video Processing》2017,11(2):227-233
An orthogonal 16-point approximate discrete cosine transform (DCT) is introduced. The proposed transform requires neither multiplications nor bit-shifting operations. A fast algorithm based on matrix factorization is introduced, requiring only 44 additions—the lowest arithmetic cost in literature. To assess the introduced transform, computational complexity, similarity with the exact DCT, and coding performance measures are computed. Classical and state-of-the-art 16-point low-complexity transforms were used in a comparative analysis. In the context of image compression, the proposed approximation was evaluated via PSNR and SSIM measurements, attaining the best cost–benefit ratio among the competitors. For video encoding, the proposed approximation was embedded into a HEVC reference software for direct comparison with the original HEVC standard. Physically realized and tested using FPGA hardware, the proposed transform showed 35 and 37 % improvements of area-time and area-time-squared VLSI metrics when compared to the best competing transform in the literature. 相似文献
865.
Easy ambient sonic-spray ionization-membrane interface mass spectrometry for direct analysis of solution constituents 总被引:1,自引:0,他引:1
Using a cellulose dialysis membrane and aqueous solutions of common drugs as a proof-of-principle example, we demonstrate that solid but permeable and flexible membranes can be used as interfaces for the direct analysis of solution constituents via easy ambient sonic-spray ionization mass spectrometry. This new combination of MS techniques, herein termed EASI-MIMS, promotes droplet pick up of the analyte from the external surface of the membrane from where the analyte has selectively permeated for proper mass spectrometry characterization and quantitation. Possible application of EASI-MIMS such as the environmental analyses of effluents, on-line monitoring of fermentation and biotransformations and on-line pharmacokinetic blood analysis are discussed. 相似文献
866.
Saied Yousefi Tarek Hegazy Renato A. C. Capuru?o Mohamed Attalla 《Canadian Metallurgical Quarterly》2008,134(5):342-351
The aging infrastructure in North America and worldwide mandates large investments in repair and improvement (R&I) activities. For organizations that own many assets, managing a large number of R&I activities is not a simple task and requires accurate estimating and scheduling so that proper budgeting and resource allocation decisions can be made. To support these decisions, this paper introduces a Web-based system that estimates the cost and duration of a user-requested R&I activity and provides alternative schedules based on resource availability. For estimating, the Web-based system hosts 32 artificial neural networks (ANNs), trained on actual historical data, for 32 common R&I activities in building projects. Each ANN incorporates a sensitivity analysis to consider the uncertainty in the input parameters on the estimate, and is linked to a central scheduling algorithm for resource allocation based on a first-come first-serve basis. The automated system helps practitioners in planning numerous R&I requests with least time, cost, and paper work. Details on system development are provided in this paper along with perceived benefits and the opinion of users on its performance. 相似文献
867.
Taís Campos Scalise Mara Cristina Lopes de Oliveira Isaac Jamil Sayeg Renato Altobelli Antunes 《Journal of Materials Engineering and Performance》2014,23(6):2164-2173
Stainless steels employed for manufacturing automotive exhaust systems must withstand severe thermal cycles, corrosive environment due to urea decomposition, and welding operations. AISI 409 ferritic stainless steel can be considered a low-cost alternative for this application. However, depending on the manufacturing conditions during welding cycles, this material can be sensitized due to the precipitation of chromium carbides at grain boundaries. In this work, the intergranular corrosion resistances of the AISI 409 ferritic stainless steel were evaluated after annealing at 300, 500, and 700 °C for 2, 4, and 6 h. Solution-annealed samples were also tested for comparison purposes. Two methodologies were used to assess the sensitization behavior of the 409 stainless steel samples: the first one was based on the ASTM A763 (practice W), while the second one was based on the double-loop electrochemical potentiodynamic reactivation test. It was possible to identify that the annealing treatment performed at 500 °C was more critical to the occurrence of intergranular corrosion. 相似文献
868.
Capelli L Sironi S Del Rosso R Céntola P Rossi A Austeri C 《The Science of the total environment》2011,409(3):595-603
Since several years odour nuisance is a serious environmental concern in the city of Terni, whose citizens are repeatedly lamenting the presence of malodours. This paper describes the olfactometric approach adopted for assessing the odour impact on the city of Terni, caused by the co-presence of three important industrial poles: the steel industry pole, the chemical pole and a third industrial pole, comprising different activities for the treatment of wastewaters and solid waste. The combination of analyses by dynamic olfactometry and dispersion modelling allowed the evaluation of the citizens' exposure to the industrial odours, resulting in both the quantification of emissions and the assessment of their impact on the territory. The overall odour emissions were estimated to be equal to 218,000 ouE s− 1: 51% from the steel industry pole, 29% from the chemical pole and 20% from the other plants, respectively. The simulation of the emission dispersion shows that the odour impact relevant to all three studied industrial poles is considerable, actually investing almost the whole city of Terni. The study results also enabled the identification of the most problematic odour sources, which turned out to be the primary emissions from the furnace for the steel industry pole, Treofan and the wastewater treatment plant for the chemical pole and the municipal wastewater treatment plant and the pulper incinerator as far as the other plants are concerned. 相似文献
869.
Elder Pacheco da Cruz Juliani Buchveitz Pires Estefani Tavares Jansen Felipe Nardo dos Santos Laura Martins Fonseca Helen Cristina dos Santos Hackbart Marjana Radünz Elessandra da Rosa Zavareze Alvaro Renato Guerra Dias 《Journal of food science》2024,89(3):1373-1386
Onion is rich in bioactive and volatile compounds with antioxidant activity. However, the pungent odor of volatile compounds (VOCs) released restricts its use. The encapsulation of red onion extract by electrospinning is an alternative to mask this odor and protect its bioactive compounds. The main objective of this study was to encapsulate red onion bulb extract (ROE) in different concentrations into zein nanofibers by electrospinning and evaluate their thermal, antioxidant, and hydrophilicity properties. The major VOC in ROE was 3(2H)-furanone, 2-hexyl-5-methyl. Incorporating ROE into the polymeric solutions increased electrical conductivity and decreased apparent viscosity, rendering nanofibers with a lower average diameter. The loading capacity of ROE on fibers was high, reaching 91.5% (10% ROE). The morphology of the nanofibers was random and continuous; however, it showed beads at the highest ROE concentration (40%). The addition of ROE to the nanofibers increased their hydrophilicity. The nanofibers’ antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, and hydroxyl radicals ranged from 32.5% to 57.3%. The electrospun nanofibers have the potential to protect and mask VOCs. In addition, they offer a sustainable alternative to the synthetic antioxidants commonly employed in the food and packaging industry due to their antioxidant activities. 相似文献
870.
Funari CS Gullo FP Napolitano A Carneiro RL Mendes-Giannini MJ Fusco-Almeida AM Piacente S Pizza C Silva DH 《Food chemistry》2012,135(3):2086-2094
The Lippia genus is used in ethnobotany as food, beverages, seasoning and antiseptic remedies, among others. The chemical compositions of fifteen extracts of six Lippia species were investigated comparatively by HPLC-PDA. To avoid data replication of previous works on this genus, Lippia lupulina Cham. root ethanol extract was selected for isolation procedures based on Principal Component Analyses (PCA) of such data. Seven compounds previously unreported in this genus were isolated from this extract (a triterpene, two furanonaphtoquinones, a furanochromone, an isoflavone, a stilbene and an iridoid). The activities of extracts, fractions and pure compounds towards Candida albicans, Candida krusei, Candida parapsilosis and Cryptococcus neoformans were investigated. Two fractions from the extract of Lippia salviaefolia leaves showed marked inhibition of fungal growth, in addition to verbascoside and asebogenin, which showed MICs lower than 15.6μg/ml and may be promising leads for the development of new antifungal agents, especially against C. neoformans. 相似文献