Hydrogenation of p‐Nitrophenol to p‐Aminophenol as a Test Reaction for the Catalytic Activity of Supported Pt Catalysts

Hydrogenation of p‐nitrophenol (PNP) to p‐aminophenol (PAP) using NaBH₄ as a reducing agent was studied as a test reaction for determining the catalytic activity of supported Pt catalysts. The initial reaction rate, which is accessible within less than 10 min via online UV‐vis spectroscopy at room temperature, ambient pressure, and in water as solvent, was applied as measure for catalytic activity. For three Pt catalysts supported on porous SiO₂, porous glass, and Al₂O₃, respectively, significant differences in the catalytic activity by almost one order of magnitude were observed. However, especially in the case of very active catalysts, limitations of the reaction by internal or external mass transfer have to be considered.     

Photocatalytic effects of TiO2 mesoporous coating immobilized on clay roofing tiles

The objective of this study was to examine the effect of the hydroxyl radicals (free and bound) produced by a TiO₂ mesoporous coating immobilized on the surface of clay roofing tiles. The efficiency of the coating was determined by microbiological and photochemical tests. In the microbiological test (pour plate method), use was made of the test bacteria Pseudomonas aeruginosa, while the photochemical test involved the degradation of para-chlorobenzoic acid, monitored by HPLC method. Both experiments were carried out without and with a scavenger (methanol and tert-butanol). The results of the measurement of the photocatalytic efficiency, and the observed changes in the measured contact angle (sessile drop method), imply the existence of a photo-induced hydrophilicity of the TiO₂ coated porous substrates. The newly designed coating represents a medium which efficiently hinders bacterial adhesion. The experiments demonstrated the existence of self-cleaning and slight self-disinfecting properties of the mesoporous coating.     

Electrochemical investigations on amorphous Fe-base alloys for alkaline water electrolysis

In this work different amorphous melt-spun Fe-alloys (Fe₈₂B₁₈, Fe₈₀Si₁₀B₁₀, Fe₆₀Co₂₀Si₁₀B₁₀) were investigated as cathode materials for the alkaline electrolysis of water. In particular, the influence of cobalt as well as the metalloids boron and silicon on the activity for the hydrogen evolution reaction (HER) was studied in 1 M KOH at 298 K using cyclic voltammetric, galvanostatic and polarization techniques. The electrocatalytic activity was evaluated in the view of the overpotential. It was found that cyclic voltammetric techniques can be used to activate the melt-spun Fe-alloys strongly. Different cyclic voltammetric activation procedures are discussed and the influence of the sweep rate and the potential window on the HER activity was elucidated. The experimental data indicate that the addition of metalloids and, most importantly, of cobalt improves the HER activity of the materials. Thus, the overpotential can be reduced by 200 mV compared to polycrystalline Ni.     

改进的Potrace提花织物图像矢量化算法

为了对提花织物图像进行矢量化,针对其颜色少、色块大的特点,提出了改进的Potrace图像矢量化算法。原始的Potrace算法只能实现对二值图像的矢量化,改进后的算法将位图中的色块逐个分解生成一个个的闭合路径,之后将这些闭合路径按照其各自分布拼接成树状结构并矢量化,最终生成一个完整的矢量图形。该算法在实际的应用中取得较好效果。     

Dimensional Description of On-line Wear Debris Images for Wear Characterization

As one of the most wear monitoring indicator, dimensional feature of individual particles has been studied mostly focusing on off-line analytical ferrograph. Recent development in on-line wear monitoring with wear debris images shows that merely wear debris concentration has been extracted from on-line ferrograph images. It remains a bottleneck of obtaining the dimension of on-line particles due to the low resolution, high contamination and particle’s chain pattern of an on-line image sample. In this work, statistical dimension of wear debris in on-line ferrograph images is investigated. A two-step procedure is proposed as follows. First, an on-line ferrograph image is decomposed into four component images with different frequencies. By doing this, the size of each component image is reduced by one fourth, which will increase the efficiency of subsequent processing. The low-frequency image is used for extracting the area of wear debris, and the high-frequency image is adopted for extracting contour. Second, a statistical equivalent circle dimension is constructed by equaling the overall wear debris in the image into equivalent circles referring to the extracted total area and premeter of overall wear debris. The equivalent circle dimension, reflecting the statistical dimension of larger wear debris in an on-line image, is verified by manual measurement. Consequently, two preliminary applications are carried out in gasoline engine bench tests of durability and running-in. Evidently, the equivalent circle dimension, together with the previously developed concentration index, index of particle coverage area （IPCA）, show good performances in characterizing engine wear conditions. The proposed dimensional indicator provides a new statistical feature of on-line wear particles for on-line wear monitoring. The new dimensional feature conveys profound information about wear severity.     

Morphological enhancement of microscopy mineral image using opening‐ and closing‐based toggle operator

To enhance unclear microscopy mineral images, an algorithm based on toggle operator using opening and closing is proposed in this paper. Firstly, the specified toggle operator using opening and closing through designing the selection rules is analysed. Secondly, after importing the multiscale theory into the specified toggle operator, useful mineral image features, especially the mineral details, are extracted using the multiscale theory‐based toggle operator. Finally, the mineral image is enhanced through the strategy of enlarging the contrast between the extracted bright and dark image features. Experimental results on different types of mineral images verified that the proposed algorithm could effectively enhance mineral images and performed better than some other algorithms. The enhanced mineral image is clear and contains rich mineral details, whereas the grey scale distribution of the original mineral image is appropriately maintained. This would be useful for the further mineral analysis. Therefore, the proposed algorithm could be widely used for image‐based mineral applications.     

COSMO-RS-PDHS: A new predictive model for aqueous electrolytes solutions

This work introduces a new tool able to predict water activities and activity coefficients of electrolytes in binary {water–electrolyte} systems. In mixtures containing electrolytes, the system is characterized by the presence of both molecular and ionic species, resulting in three different types of interactions: ion–ion, molecule–molecule and ion–molecule.Ion–ion interactions are governed by electrostatic forces between ions that have a much longer range than other intermolecular forces. The long range interactions between ions are taken in account by the Pitzer term based on the Debye–Hückel theory.Molecule–molecule and ion–molecule interaction forces are known to be short-range in nature. To determine short range mean activity coefficients of salts in {water–electrolyte} binary mixtures, a chemical treatment of ions solvation is combined with the predictive power of the COSMO-RS model. The main originality of this work resides in this chemical treatment model that provides the thermodynamic relations which enable to determine the equilibrium properties of the real solution {water–salt}, knowing those of a hypothetical mixture containing water and hydrated clusters.The resulting model called “COSMO-RS-PDHS” predicts results that are in good agreement with experimental data.     

Testing activity‐based costing to large‐scale combined heat and power plant using bioenergy

This paper deals with the energy production and economics of a large‐scale biomass‐based combined heat and power (CHP) plant. An activity‐based costing model was developed for estimating the production costs of the heat and power of the bio‐CHP. A 100 MW plant (58 MW heat, 29 MW electricity) was used as reference. The production process was divided into four stages: fuel handling, fluidized bed boiler, turbine plant, and flue gas cleaning. The boiler accounted for close to 50% of the production costs. The interest rates and the utilization rate of the CHP had a significant effect on the profitability. We found that below 4000–4500 h per year utilization, the electricity production turned unprofitable. However, the heat production remained profitable with high interest rate (10%) and a low utilization rate (4000 h). The profitability also depended on the type of biomass used. We found that, e.g. with moderate interest rates and high utilization rate of the plant, the bio‐CHP plant could afford wood and Reed canary grass as fuel sources. Copyright © 2013 John Wiley & Sons, Ltd.