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91.
Glass slides are widely used in high-throughput analysis and are available commercially with surfaces activated, etched, and channeled. Thin glass microscope slides are shown here to be suitable sample supports for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. As a demonstration, lectins immobilized on glass slides with activated surfaces are used to concentrate and purify agglutinated Bacillis spores. It is expected that such slides will provide a rapid, inexpensive way to evaluate and implement new strategies involving MALDI MS readout. 相似文献
92.
Removal of chromium from aqueous solutions by diatomite treated with microemulsion 总被引:10,自引:0,他引:10
In order to evaluate the sorption of heavy metals, a crude diatomite was impregnated with a microemulsion which showed remarkable increase in chromium sorption capacity as compared to untreated diatomite. Samples with two different granulometries were investigated, both yielding practically complete adsorption. The adsorption process is pH dependent and the best results for the initial Cr (III) concentration of 1.5 g/L were obtained at pH 2.95. The effect of the concentration of the chromium synthetic solution was also investigated. The adsorption isotherms were obtained (30. 40 and 50 degrees C) and the Freundlich and Langmuir models were used to determine the adsorption capacity of the adsorbent. Following the adsorption step, a desorption process was carried out using several eluant solutions. The best results were obtained using hydrochloric acid (100%) as eluant. 相似文献
93.
Neto A. Llombart N. Gerini G. Bonnedal D.M. de Maagt P. 《Antennas and Propagation, IEEE Transactions on》2007,55(8):2185-2193
We describe the use of electromagnetic bandgap (EBG) super-layers to improve the shape of reflectors illumination function. Following an investigation of the leaky wave pole singularities of the EBG Green's function, the shape of the radiation patterns of small apertures in ground planes are optimized. The maximization of the reflector aperture efficiency can be obtained by properly tuning the super layers geometrical parameters. A prototype of such feed has been designed, manufactured and tested. The results indicate that the inclusion of the EBG, increases the aperture efficiency of the feed+reflector system to values higher than 80%, over a 10% bandwidth. These low profile feeds are compatible with printed circuit board and/or integrated technology. 相似文献
94.
J. M. Pardal S. S. M. Tavares M. P. Cindra Fonseca M. R. da Silva J. M. Neto H. F. G. Abreu 《Journal of Materials Science》2007,42(7):2276-2281
The magnetic properties and hardness of a Ni–Co–Mo–Ti maraging steel 300 grade were measured as function of aging temperature.
The austenite and martensite phase quantifications in the different heat treatment conditions were carried out by X-ray diffraction
using direct comparison method. The behavior of the hardening, magnetization saturation and coercive force against aging temperature
and time were explained taking into account the variation of austenite volume fraction with aging time and temperature. 相似文献
95.
Ramón Fernandez Astudillo Dorothea Kolossa Alberto Abad Steffen Zeiler Rahim Saeidi Pejman Mowlaee João Paulo da Silva Neto Rainer Martin 《Computer Speech and Language》2013,27(3):837-850
This paper presents a new approach for increasing the robustness of multi-channel automatic speech recognition in noisy and reverberant multi-source environments. The proposed method uses uncertainty propagation techniques to dynamically compensate the speech features and the acoustic models for the observation uncertainty determined at the beamforming stage. We present and analyze two methods that allow integrating classical multi-channel signal processing approaches like delay and sum beamformers or Zelinski-type Wiener filters, with uncertainty-of-observation techniques like uncertainty decoding or modified imputation. An analysis of the results on the PASCAL-CHiME task shows that this approach consistently outperforms conventional beamformers with a minimal increase in computational complexity. The use of dynamic compensation based on observation uncertainty also outperforms conventional static adaptation with no need of adaptation data. 相似文献
96.
Leonardo Dallegrave Afonso Viviana Cocco Mariani Leandro dos Santos Coelho 《Expert systems with applications》2013,40(9):3794-3802
System reliability analysis and optimization are important to efficiently utilize available resources and to develop an optimal system design architecture. System reliability optimization has been solved by using optimization techniques including meta-heuristics. Meanwhile, the development of meta-heuristics has been an active research field of the reliability optimization wherein the redundancy, the component reliability, or both are to be determined. In recent years, a broad class of stochastic meta-heuristics, such as simulated annealing, genetic algorithm, tabu search, ant colony, and particle swarm optimization paradigms, has been developed for reliability-redundancy optimization of systems. Recently, a new kind of evolutionary algorithm called Imperialist Competitive Algorithm (ICA) was proposed. The ICA is based on imperialistic competition where the populations are represented by countries, which are classified as imperialists or colonies. However, the trade-off between the exploration (i.e. the global search) and the exploitation (i.e. the local search) of the search space is critical to the success of the classical ICA approach. An improvement in the ICA by implementing an attraction and repulsion concept during the search for better solutions, the AR-ICA approach, is proposed in this paper. Simulations results demonstrates the AR-ICA is an efficient optimization technique, since it obtained promising solutions for the reliability redundancy allocation problem when compared with the previously best-known results of four different benchmarks for the reliability-redundancy allocation problem presented in the literature. 相似文献
97.
Janaina I. S. Aguiar Jéssica S. G. Neto Sarah M. Almeida Claudia R. E. Mansur 《应用聚合物科学杂志》2013,128(3):1390-1397
During extraction of crude oil, water is generally present in the oil. This water‐in‐oil (w/o) mixture undergoes turbulent flow that promotes sheer forces, resulting in the appearance of emulsions. These emulsions can be highly stable due to the presence of compounds with polar characteristics such as asphaltenes, which act as natural emulsifiers and form resistant films at the oil–water interface. Nonionic surfactants based on polyoxides are widely used to prevent the formation or to break down w/o emulsions. To shed more light on the destabilization mechanism of w/o emulsions promoted by these surfactants, in this study the techniques of tensiometry and Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR‐ATR) were applied to study the interface formed by poly(ethylene oxide)‐poly(propylene oxide) (PEO‐PPO) block copolymers and asphaltenic petroleum fractions. Initially, the critical micelle concentration of the copolymers in aqueous solution was determined. The results agreed with those found by tensiometry. The bottle test was used to evaluate the break‐down of the w/o emulsions in the presence of the PEO‐PPO block copolymers, and the results presented good agreement with those obtained by tensiometry and FTIR‐ATR. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 相似文献
98.
99.
R.F. Tavares Neto M. Godinho Filho 《Engineering Applications of Artificial Intelligence》2013,26(1):150-161
Ant Colony Optimization is a swarm intelligence approach that has proved to be useful in solving several classes of discrete and continuous optimization problems. One set, called scheduling problems, is extremely important both to academics and to practitioners. This paper describes how the current literature uses the ACO approach to solve scheduling problems. An analysis of the literature allows one to conclude that ACO is a hugely viable approach to solve scheduling problems. On the basis of the literature review, we were not only able to derive certain guidelines for the implementation of ACO algorithms but also to determine possible directions for future research. 相似文献
100.
Parallelism in dynamic programming is considered within the specificity of optimal control. We present the program PDVP developed for solving a general deterministic discrete-time optimization problem by means of a parallel dynamic programming algorithm on the state variables. Multitasking and vectorization are considered from the viewpoint to implement PDVP on a CRAY-2. The performances are analysed through a significant application to the optimization of satellite trajectories. Promising results are obtained. 相似文献