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The influence of the Zn–Cr electrodeposition bath composition, cathode current density under direct current conditions, and the average pulse current density and the current density under pulse plating current conditions on the content of chromium in the obtained Zn–Cr coatings, the current efficiency and their corrosion properties were investigated. The obtained Zn–Cr coatings contained from about 0.01 wt-% to about 10 wt-%. The corrosion resistance largely depended on the chromium content of the coating, but also on the morphology and surface development. The best corrosion resistance was achieved for Zn–Cr alloy coatings obtained under impulse current conditions for average current densities 3 and 4 A dm−2, while cathodic peak current densities were 30 and 40 A dm−2. [ABSTRACT FROM AUTHOR]

An innovative low-cost method of aluminium surface treatment to obtain stable superhydrophobic properties is presented. An aluminium anodising method was combined with surface abrasive blasting as a mechanical pre-treatment to obtain combined microscale roughness and nonporous surface structure. The produced layer was impregnated with fatty acid. The surface morphology was examined by SEM and optical microscopy. The influence of the process parameters on the wettability of the aluminium surface was investigated. The features of the prepared samples were tested in terms of the durability of the coating. The test results confirm the stable superhydrophobic properties of the obtained layers with contact angle larger than 150° and roll-off angle less than 5°. [ABSTRACT FROM AUTHOR]

A dielectric resonator method of measuring electrical sheet conductivity of electrolytic silver coatings is presented. The method is compared with standard methods normally used for conductivity characterisations of metal coatings. Three types of electrolytes to deposit silver layers have been used and sheet conductivity was measured for each type of coating. The results revealed different values for different types of coatings. The dielectric resonator method seems to be very useful for electrolytic metal coating characterisations. [ABSTRACT FROM AUTHOR]

The study aimed to test the durability of coatings under natural conditions. The present study focused on the changes in wettability and additional properties of the coatings under natural conditions. The specimens were subjected to outdoor exposure and additionally immersed in the pond. Impregnating porous anodized aluminum is a popular production method for hydrophobic and superhydrophobic surfaces. However, prolonged exposure of such coatings to natural conditions causes leaching of the impregnate and, thus, the loss of hydrophobic properties. After the loss of hydrophobic properties, all kinds of impurities and fouling adhere better to the porous structure. Additionally, deterioration of anti-icing and anti-corrosion properties was observed. Finally, the self-cleaning, anti-fouling, anti-icing and anti-corrosion properties were comparable or even worse to those of the hydrophilic coating. In the case of superhydrophobic specimens, during outdoor exposure there was no loss of superhydrophobicity, self-cleaning and anti-corrosion properties. Still, despite this, the icing delay time dropped. During outdoor exposure, the structure, which initially had anti-icing properties, may degrade. Nevertheless, the hierarchical structure responsible for the superhydrophobic effect can still be preserved. The superhydrophobic coating initially had the best anti-fouling properties. However, the coating was also gradually losing its superhydrophobic properties during water immersion.

According to the idea of sustainable development, humanity should make every effort to care for the natural environment along with economic development. Decreasing water resources in the world makes it necessary to take action to reduce the consumption of this resource. This article presents the results of research conducted to improve the use of recyclable materials in line with the circular economy model. The research focused on the development of a technological solution for the recovery of raw materials from galvanic wastewater. The concept of a galvanic wastewater treatment system presented in the article includes wastewater pre-treatment in the ultrafiltration (UF) process and water recovery in the reverse osmosis (RO) process. In addition, the purpose of the work was to manage post-filtration waste (RO retentate) containing high concentrations of zinc in the process of galvanizing metal details. The obtained results indicate that it is possible to reduce the amount of sewage from the galvanizing industry by reusing the recovered water as technical water in the process line. The carried-out model tests of galvanizing confirmed the possibility of using RO retentate for the production of metal parts. The achieved results are a proposal to solve the problem of reducing the impact of galvanic wastewater on the environment and to improve the profitability of existing galvanizing technologies by reducing the consumption of water and raw materials.

The aim of this study was to obtain a superhydrophobic coating by modifying anodized aluminum using polydimethylsiloxane (PDMS). In order to obtain a superhydrophobic coating on an aluminum substrate, a multistage treatment was implemented. Specimens of aluminum were treated by abrasive blasting, anodization in sulfuric acid, impregnation by PDMS, rinsing in toluene to remove excess of PDMS, and curing. A rough surface with an additional low free energy layer on it resulted in a superhydrophobic effect. The coating obtained has an average contact angle of 159°. The specimens were tested in terms of durability in natural conditions. Additionally, anti-icing and anti-fouling properties were evaluated. The coating was compared with anodized aluminum obtained by a basic process.

We report the complex cytogenetic analysis of a novel melanoma cell line (M35/01) established from a vertical growth phase of a superficial spreading melanoma. Similarly to its parental tumor, this cell line metastasizes to the liver. Using combined molecular cytogenetic techniques, we could identify a reservoir of chromosomal alterations in M35/01. In addition, we had sufficient amount of DNA from both the original primary tumor and the cell line which allowed for the comparison of their genetic patterns by chromosomal CGH. Several common alterations were found indicating the same clonal origin. These alterations included gains of 6p, 7q, 15q and deletions of 9, 10, 16q and 17p. Chromosomal losses present only in the cell line were detected on chromosome 4, 16p, 18 and gains on 20p12-qter. Array CGH analysis of the M35/01 cell line provided similar results with a much higher resolution, representing relatively high level gains on 7q31.2-q31.31, 15q25, 20q, and losses on 4q28, 9p21-p24, 9q21-q22, 10q25, 16q13-q23, 17p12-13 and 18q12-23. Using SKY-FISH, several structural alterations could be detected which were not recognized by conventional cytogenetics. Except for chromosome 18, none of the centromeres showed normal distribution by FISH. Our analysis shows that a high number of chromosomal alterations, which are known to be nonrandomly associated with melanoma progression, can be found by the combined use of different molecular genetic techniques. This new melanoma cell line would be an excellent model for investigating the mechanism of organ specific-metastatic events of malignant melanoma.