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as a probe to evaluate the photocatalytic efficiency of the TiO 2 /CS system under low energy light source. Therefore, the objectives of this study were to fabricate, optimize and apply a simple layer-by-layer TiO 2 /CS system consisting of TiO 2 and

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Abstract  

Information properties of analytical results together with other important parameters especially economic ones can be used for the optimization of analytical procedures. Therefore, we have proposed a computational technique for the optimization of multielement neutron activation analysis (NAA) based on the information content and profitability. The optimization starts with the prediction of the -ray spectra to be expected during analysis under given experimental conditions (sample size, irradiation, decay and counting times etc.) and with the calculation of detection and determination limits. In the next step, the information contents for the determination of particular elements and for the simultaneous determination of element groups are computed. The information content depends or is closely connected with such properties of the method as selectivity, sensitivity, precision, accuracy and, as in the other cases of trace analysis, also with the detection limit. Then, the information profitability (IP) taking into account the information content and relevance (appreciation of specific information according to its contribution to the solution of a given problem) together with economic aspects can be calculated. This function can be used for the optimization of a particular NAA procedure, for the mutual comparison of different variants of NAA and also for the comparison with other analytical methods. The use of information profitability for the optimization of NAA is shown on a practical example of the INAA analysis of urban particulate matter SRM 1648 produced by NBS (USA).

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An activation analysis procedure has been suggested which includes correction of the measurement time in accordance with the normalized error by processing the date during observation with subsequent optimization of the activation and cooling times. Such a procedure enables one to intensify the analysis providing the analytical error is normalized. A mathematical description of the procedure is given, and the optimization of the components of the measurement and their treatment in accordance with the normalized error is performed. This procedure is most efficient for analysis of a great number of samples similar in elemental composition, i.e. in systems used in industry. The measurement may also be applied in scientific studies. The features concerning application of the optimized measurements in activation analysis with various sources of activating particles, as well as in other radioanalytical methods, are considered.

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Qualitative identification of Cu, Sn, Pb, Ni, and Fe in Cu-alloys is presented. The method involves anodic sampling of alloys, separation and identification by thin-layer chromatography (TLC). The powerful desktop-computer tool makes it easy to optimize ternary solvent mixtures. Optimization was performed graphically by means of R si≥1 as a selected separation criterion. Mobile phase composition for optimal separation was determined as MeOH−HCl−H2O (60:35:5, v/v). The method was applied to Persian helmet as real sample.

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A method for determination of the composition of binary mixtures of a metal or radionuclide species by optimized repeated two-phase separations (SORTS) was proposed and theoretically substantiated. Its principle consists in repeated equilibration of two immiscible phases, one being the original liquid or solid matrix with minimal adjustment of its composition and varying the phase ratio (separation stage cut) as the optimized parameter. The batch separation technique may consist in the repeated solvent extraction or aqueous biphasic distribution, or in the replicate equilibration with solvent or leaching solution. Results of SORTS can be presented e.g. by Tukey box diagrams as the characteristic fingerprints of original species composition.

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both OFAT (one factor at a time), and DOE were both applied to conclude optimum separation conditions. Face centered cube response surface experimental design was chosen to carry out the optimization experiments studying the effect of six factors

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The production of astatine isotope 211 for nuclear therapeutic applications requires to minimize its210At contaminations. This work provides a numerical programme, allowing an optimization of bombarding conditions of the cyclotron isotope production in order to obtain high yields of the mean isotope as well as lowest contaminations of other by-produced nuclides. Finally, results are compared with experimental values.

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XRFS can be successfully used for routine on-line analysis of different agricultural products, for instance where food quality control is necessary. The optimization of the system for such purposes and the results obtained are shown on the example of the analysis of coffee.

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Herein, we illustrate how microreactor technology can be used as a tool for reaction screening and optimization, in addition to improving the reaction chemistry. We report the in-situ generation of azo compounds by reactive quenching of diazonium intermediates in microreactors. This involves an electrophilic aromatic substitution reaction, namely, an azo-coupling reaction performed in continuous-flow systems in the presence of a phase transfer catalyst with great emphasis on compounds that do not easily couple. Capitalizing on the benefits of a large surface area and the short molecular diffusion distances observed in microreactors, in-situ phase transfer catalyzed azo-coupling reaction of diphenylamine to p-nitroaniline was investigated. A rapid and easy optimization protocol was established which yielded a 99%, 22%, and 33% conversion of diphenylamine, carbazole, and triphenylamine, respectively, in approximately 2.4 min.

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Summary

Charged-coupled device (CCD) noise can be a serious problem during videoscanning, especially when scanning dark plates with weakly fluorescent spots. The proper denoising of videoscans inside mathematical environments is a critical part of any advanced chemometric processing. The paper reports comparison and optimization of representative videoscan denoising by different techniques. Several kind of filters (averaging, circular, Gaussian, Savitzky-Golay, median, Wiener, FIR) and wavelet shrinkage (twelve mother wavelets from the Daubechies, Symmlet, and Coiflet family, five decomposition levels, and soft/hard thresholding) were optimized against noise autocorrelation or mean-squared error to the reference image. The reference image was obtained by grabbing and averaging 256 CCD frames. The median filter is the winner of the competition; other filters except Gaussian and wavelet shrinkage at high decomposition level are also sufficient and good ways of videoscan denoising. The Gaussian filter and wavelet shrinkage at low decomposition level performed worst and could not be recommended.

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