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51.
H. Bustince Author Vitae E. Barrenechea Author VitaeAuthor Vitae J. Fernandez Author VitaeAuthor Vitae 《Pattern recognition》2010,43(9):3188-3192
In this work we develop some reflections on the thresholding algorithm proposed by Tizhoosh in [16]. The purpose of these reflections is to complete the considerations published recently in [17] and [18] on said algorithm. We also prove that under certain constructions, Tizhoosh's algorithm makes it possible to obtain additional information from commonly used fuzzy algorithms. 相似文献
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Ronald G. Pinnick Steven C. Hill Paul Nachman J. David Pendleton Gilbert L. Fernandez Michael W. Mayo 《Aerosol science and technology》2013,47(4):653-664
We have constructed a laser-based particle counter that detects the fluorescence, as well as the elastic scattering, from individual airborne particles as they traverse a laser beam. This fluorescence particle counter (FPC) can detect fluorescence from μm-sized Bacillus subtilis spore agglomerates when illuminated with intense light at 488 nm from an argon ion laser, either ~ 0.7 kW cm?2 extracavity or ~ 50 kW cm?2 intracavity. We suspect that flavins in the spores are the molecules primarily responsible for the fluorescence, because the peak fluorescence emission of the biological materials at this excitation wavelength is in the range 530–550 nm, which is characteristic of flavins. Fluorescence from kaolin, hematite, and polystyrene particles was not detectable; the lack of fluorescence indicates that the FPC may be able to differentiate between biological and nonbiological aerosols. The FPC samples aerosol-laden air at a rate of ~ 1 mL s?1, and is capable of measuring aerosol concentrations up to several thousand per milliliter. The FPC may be helpful in detecting and characterizing airborne bacteria and other airborne particles of biological origin. 相似文献
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A large number of data on mobility and mass have been newly obtained or reanalyzed for clusters of a diversity of materials, with the aim of determining the relation between electrical mobility (Z) and mass diameter d m = (6m/ π ρ ) 1/3 (m is the particle mass and ρ the bulk density of the material forming the cluster) for nanoparticles with d m ranging from 1 nm to 6.5 nm. The clusters were generated by electrospraying solutions of ionic liquids, tetra-alkyl ammonium salts, cyclodextrin, bradykinin, etc., in acetonitrile, ethanol, water, or formamide. Their electrical mobilities Z in air were measured directly by a differential mobility analyzer (DMA) of high resolution. Their masses m were determined either directly via mass spectrometry, or assigned indirectly by first distinguishing singly (z = 1) and doubly (z = 2) charged clusters, and then identifying monomers, dimers, … n-mers, etc., from their ordering in the mobility spectrum. Provided that d m > 1.3 nm, data of the form d m vs. [z(1+m g /m) 1/2 /Z)] 1/2 fall in a single curve for nanodrops of ionic liquids (ILs) for which ρ is known (m g is the mass of the molecules of suspending gas). Using an effective particle diameter d p = d m + d g and a gas molecule diameter d g = 0.300 nm, this curve is also in excellent agreement with the Stokes-Millikan law for spheres. Particles of solid materials fit similarly well the same Stokes-Millikan law when their (unknown) bulk density is assigned appropriately. 相似文献
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The feasibility of quantifying the perceived active ingredient (P57) in Hoodia gordonii raw material using Fourier transform near- and mid-infrared spectroscopy combined with chemometric techniques was investigated. The concentration of P57 (a triterpene glycoside) was determined in 146 plant samples with liquid chromatography coupled to mass spectrometry and these values were used to develop a calibration model based on the partial least squares projections to latent structures (PLS) and orthogonal projections to latent structures (O-PLS) regression algorithms. The performance of each calibration model was evaluated according to the root mean square error of prediction (RMSEP) and correlation coefficient (R2). The PLS model with 2nd derivative pre-processing predicted P57 content based on the FT-NIR spectra with the best accuracy and a correlation coefficient (R2) value of 0.9629 and the lowest RMSEP of 0.03%. These results demonstrated that FT-NIR spectroscopy can be used to rapidly quantify P57 in H. gordonii raw material with high accuracy. 相似文献
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Rey Alvaro Datta-Gupta Akhil Paulo Ballin 《Journal of Petroleum Science and Engineering》2011,78(2):415-430
In this paper we propose an efficient and novel technique that handles production discontinuities through a resampling of the production data, eliminating high frequency production details in a transformed domain. The technique also reduces non-monotonic behavior and results in a response more suitable for the GTTI based misfit calculations. Our proposed approach has been applied to an offshore turbidite reservoir with extensive well intervention resulting in highly detailed production responses. The static model contains more than three-hundred-thousand cells, complex sand depositional distribution combined with fault structures, four pairs of injector-producers, deviated producing wells and more than 8 years of production history. Previous history matching attempts using traditional approaches had difficulties matching production response at the individual well level. With our proposed modifications to the GTTI approach, a significant improvement was obtained on the well level match quality. Most importantly, by visualizing the streamlines and the dynamic adjustment of flow paths during history matching, we could easily identify the areas of inconsistency between the geologic model and the production data. The calibrated geologic model and streamline trajectories provided important insight about communication within sand channels, differences in flow paths and barriers that have not been included in the previous geologic and seismic interpretation. 相似文献
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G. Fernandez J. Moon 《Tunnelling and Underground Space Technology incorporating Trenchless Technology Research》2010,25(5):560-566
Field observations indicate that current engineering practice does not consistently estimate ground water flows into unlined rock excavated tunnels due to various factors that analytical solutions do not take into account. These factors include significant geological features, groundwater drawdown, inadequate estimates of hydraulic conductivity from packer tests, and stress-induced rock-mass permeability reduction in the vicinity of tunnel (lining-like zone). A key variable that is not properly accommodated in current practice, is the hydro-mechanical interaction within the joints in the surrounding rock mass. The significance of this variable is discussed in the 1st part of the paper which presents an analytical solution assessing ground water inflow rate into a tunnel using a mathematical derivation that takes into account the excavation-induced rock permeability reduction in the vicinity of a tunnel based on hydro-mechanical coupling effect. In the 2nd part of the paper, results from numerical analysis are presented to verify the proposed analytical solution for estimating ground water inflow rate into a tunnel. Further studies are currently underway to identify other key variables and their impact on the behavior of unlined tunnels and hydrological flow regime in the surrounding fractured rock mass using a distinct element method program which can fully consider hydro-mechanical coupled behavior of joints. 相似文献
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Rosana de Cassia de Souza Schneider Luciano Roni Silva Lara Marieli Milanesi Ceolin Jonas Alvaro Kaercher Manuella Schneider 《Clean Technologies and Environmental Policy》2013,15(6):977-985
In the vegetable oil chemical industry, hydrogenation is one of the most important processes. An alternative method for vegetable oil hydrogenation is the use of catalytic transfer hydrogenation (CTH), which can utilize organic molecules as hydrogen donors at ambient pressure. These alternative processes should be optimized in relation to the variables required for a good conversion and impacts should also be known to be minimized. An assessment of the environmental impact of laboratory scale chemical processes is an important tool to improve the technological aspects of a process (increased yields, reduced production times, lower costs) and it can also lead to the creation of a cleaner technology. Using the Leopold Matrix, we have succeeded in developing a more efficient and cleaner process for the CTH of castor oil using Raney Ni as a catalyst and cyclohexene or isopropanol as a hydrogen donor solvent. The results of the technical and environmental assessments showed that the extent of conversion for the unsaturation reaction was high (>99 %), and the environmental impact of the process could be significantly reduced to create a cleaner technology. It was found, after process optimization, that the remaining environmental impacts were negative (67.48 %), local (78.95 %), temporary (95.33 %), direct (80.12 %), and reversible (95.32 %). 相似文献