The effect of microstructure on hydrogen permeability of high strength steels

Hydrogen diffusivity and trapping have been studied in two advanced high strength steel grades and model samples using electrochemical permeation test. Microstructures of CP1000 and DP1000 steels consist of ferrite, martensite and a small fraction of retained austenite. In addition, bainite is present in CP1000. Model phases with predominance of a particular phase have been prepared by specific heat treatment. DP1000 has shown the lowest diffusivity among all materials, while ferritic model sample has shown the highest. Differences in hydrogen diffusion coefficient values are linked to trapping microstructural characteristics and grain size.     

Potential and current density distributions along a bipolar electrode

Potential and current density distributions were modelled and measured for an electrochemical cell with a bipolar electrode. The dimension of the bipolar electrode in the direction of current flow was extended, to enable experimental determination of the electrode potential and the local current densities at various positions inside the electrolyte and in the electrode body. The experimental results showed that the most active regions of the bipolar electrode are located at the ends of the bipolar electrode facing the terminal electrodes. The equations corresponding to the mathematical model of the experimental cell were solved using the finite volume method and gave very good qualitative agreement with the experimental data. However, some discrepancies between model predictions and experimental data were evident in the active parts of the bipolar electrode and in the variation of the terminal voltage with the total current. This was explained in terms of the active electrolyte cross-section and the electrode surface area being diminished due to the presence of gas bubbles in the system.     

Exploring color attractiveness and its relevance to fashion

Many studies have been conducted on the phenomenon of color preference, with the aim of identifying the key color preferences. Most of the previous studies have been placing blue in the most preferred position and green-yellow in the least preferred position. This study was conducted online and aims to showcase new color preference trends in the digital age. The colors selected for this study were based on the colors most frequently mentioned in previous color studies. Here, we show an evaluation using 14 Pantone colors as stimuli on the sample of (N = 146) participants based on pairwise adjectives (attractive-unattractive). Principal component analysis and other multivariate statistics were used to examine participants' color attractiveness. In addition, gender and age were examined to determine if they had an impact on color attractiveness ratings. Results show that participants tend to prefer distinctive colors (black, pink, yellow), but there are slight differences in preferences that could be related to the influence of gender and age.     

Experimental investigation of novel hybrid phase change materials

Clean Technologies and Environmental Policy - The novel potential of hybrid phase change materials (PCM) as a mix of animal fat, specifically pork fat (lard), with edible and waste oil from the...     

RMS Delay Spread Assessment for Indoor UWB Propagation Channels

Wireless Personal Communications - The RMS delay spread is often used to quantify the probability of inter-symbol interference in a propagation channel. A novel and straightforward procedure to...     

Further progress in the research of fin‐based passive cooling technique for the free‐standing silicon photovoltaic panels

The paper deals with a passive air‐based cooling technique of photovoltaic (PV) panels in operating conditions. Cooling technique is done by specific type of using aluminium fins, and its main purpose is to increase the electrical efficiency of the PV panel. An increase in electrical efficiency can be achieved because of temperature degradation effect, where the PV panel yields less power at higher operating temperatures (the PV panel's efficiency can drop by up to 0.5%/°C). To confirm a cooling technique, a medium‐sized PV system was used in a 2‐month experiment. The experiment was done in realistic operating conditions, and all working parameters were thoroughly measured. After the analysis of the data, no significant raise in electrical efficiency was recorded throughout the experiment. A numerical approach was conducted, based on gained experimental data. Developed numerical model gave explanations of experimental results and provided an insight in heat flow through the PV cell. Later on, developed numerical model was used to propose new cooling variations of the fin‐based technique and to further examine the overall potential of air based passive cooling techniques. It was shown that cooling effect by up to 5°C is a realistic expectation for this technique in described operating conditions.