A large number of infrastructural concrete buildings are protected against aggressive environments by coating systems. The functionality of these coating systems is mainly affected by the composition and thickness of the individual polymeric layers. For the first time ever, a mobile nuclear magnetic resonance (NMR) sensor allows a non-destructive determination of these important parameters on the building site. However, before this technique can be used on steel-reinforced concrete elements, the potential effect of the reinforcement on the measurement, i.e. the NMR signal, needs to be studied. The results show a shift of the NMR profile as well as an increase of the signals amplitude in the case of the reinforced samples, while calculating the thickness of concrete coating leading to identical results.

The article presents the results of permeability measurements of a zirconium alcohol coating applied on moulds and cores. The introduction extensively discusses the reasons for the application of protective coatings, as well as their advantages and disadvantages. Also, the problems related to the application of protective coatings are presented i.e. limited permeability and thus the possibility of the presence of gas-originated defects in the casts. Next, the paper discusses the methods of measuring the permeability of protective coating proposed by Falęcki and Pacyniak. The study also presents an indirect permeability measurement method. For the investigations, zirconium alcohol coatings with the three conventional viscosities 10, 20 and 30s were used. The viscosity was determined by means of the Ford cup with the clearance of 4mm. The coatings were applied onto profiles of Φ 50 x 50 mm, made of moulding sand consisting of a sand matrix with the mean grain size of dL = 0,11, 17, 24, 31 and 34 mm and phenol-formaldehyde resin. The effect of the matrix grain size on the permeability of the sand with and without a coating was determined.

This article presents measurements of the thickness of alcohol-based coatings on sand foundry cores and moulds. These coatings were applied using two methods, the dipping method and the painting method. For the purposes of the study, a zircon alcohol-based coating was prepared with three different levels of nominal viscosity; very thin at 10s, average at 20s, and thick at 30s. The coating was applied to a core made of quartz sand and furan resin. The cores were made of sand with three different grain sizes; dL = 0.22 mm – fine sand, dL = 0.33 mm medium sand, and dL = 0.47 mm coarse sand. In the study, the thickness of the coating obtained to the core was measured immediately after application as well as after drying. Additionally, the extent of penetration into the intergranular spaces of the core matrix was measured. On the basis of this study, the impact of the grain size of the core matrix on the thickness of the coating and its penetration into the core was assessed. The thickness of coatings obtained using different application methods was also assessed.

In view of the ecological hazards of chemicals, pot experiments were conducted to determine the efficacy of Trichoderma sp. against Macrophomina phaseolina. Greenhouse evolution of the interaction between M. phaseolina isolates and Trichoderma sp. isolates revealed a very highly significant (p = 0.0000). M. phaseolina isolate x antagonist isolate interaction for all the following parameters: preemergence damping-off, postemergence damping-off, survival, plant height, and dry weight. This interaction implies that a single isolate of antagonist can be highly effective againstan isolate of M. phaseolina, but may have only minimal effectsonotherisolatesof M. phaseolina. Therefore, isolates of antagonist should be tested against as many isolates of M. phaseolina as possible, as this will improve the chance of identifying antagonist isolates effective against several isolates of M. phaseolina.

The paper presents the results of the electrodeposition of nickel composite coatings reinforced with the ceramic SiC particles. A Watts type galvanic bath modified with various organic additives was used. These additives were: 2-sulfobenzoic acid imide (LSA), dioctyl sulfosuccinate sodium salt (DSS), sodium dodecyl sulfate (SDS), tris (hydroxymethyl) aminomethane (THAM) and hexamethyldisilizane (HMDS). The nickel composite coating was electrodeposited on a 2xxx aluminum alloy series substrate (EN-AW 2017) with zinc interlayer. Studies concerned the effect of the applied organic additives on properties of composite coatings such as: microstructure, microhardness, adhesion to the substrate, corrosion resistance and roughness. The structure of the coatings was assessed by scanning electron microscopy and light microscopy. Based on the studies of zeta potential it was found that the bath modification had a significant impact on the amount of the ceramic phase embedded in metal matrix. The tests conducted in a model 0.01 M KCl solution were not fully representative of the true behavior of particles in a Watts bath.

The objective of the research in this work was the modification of structure of carbide-type chromized layers, by the combination of diffusion chromizing with subsequent PVD treatment, consisting of chromium nitride deposition, carried out to improve their tribological properties. As a result, hybrid layers on the surface of tool steel were obtained. For comparison, the properties of single chromized carbide layers obtained in a diffusion chromizing process were tested. Investigations of layer microstructure, their mechanical properties, surface topography, adhesion of layers to the steel substrate, as well as tribological properties were conducted. The layer microstructure was characterized by X-ray diffraction and scanning electron microscopy. Topography of the layer surface was studied by an optical profilometer. The scratch test for investigations of layers adhesion to the steel substrate was used. Testing of tribological properties (linear wear) of the layers was performed by the three-cylinder-cone method. It was shown, that hybrid layers are characterized by a significantly smaller surface roughness than that of chromized carbide layers and their wear resistance improved almost twice with respect to carbide layers.

The influence of the refractory coating which is a mixture of silica flour and kaolin on the surface roughness of the plate castings produced

using evaporative patterns had been considered in this work. The kaolin was used as a binder and ratio method was employed to form basis

for the factorial design of experiment which led to nine runs of experiments. Methyl alcohol at 99% concentration was used as the carrier

for the transfer of the coating to the surface of the patterns. Pouring temperature was observed as a process parameter alongside the mix

ratios of the coating. Attempts were made to characterize the refractory coating by using two methods; differential thermal analysis (DTA)

and X-ray diffraction. Attempt was also made to characterize the casting material. Gating system design was done for the plate casting to

determine the correct proportions of the gating parameters in order to construct the gating system properly to avoid turbulence during

pouring of liquid metal. A digital profilometer was used to take the measurements of the surface roughness. It was observed that the mix

ratio 90% silica flour-10% kaolin produced the lowest value of the surface roughness of the plate castings and had the lowest material loss

in the DTA test. The pouring temperature of 650o

C produced best casting.

An analysis of the effect of drawing speed on the formation of a zinc coating in the multi-stage fine steel wire drawing process has been carried out in the article. Pre-hardened 2.2 mm-diameter material was drawn into 1.00 mm-diameter wire in 6 draws on a multi-stage drawing machine. The drawing process was carried out at a drawing speed of 5, 10, 15, 20 and 20 m/s, respectively. Mechanical tests were tests were performed for the final wires to determine their yield strength, ultimate tensile strength, uniform and total elongation and reduction in area. The thickness of the zinc coating on the wire surface was determined by the gravimetric method and based on metallographic examination. The use of electron scanning microscopy, on the other hand, enabled the identification of individual phases in the zinc coating. The above investigations were supplemented with corrosion testing of 1.00 mm-diameter wires. It has been demonstrated that drawing speed significantly influences not only the thickness of the zinc coating on the drawn wire surface, buts also its morphology and corrosion resistance.

The paper discusses the results of investigations of material, tribological and anti-corrosion properties of hybrid coatings of the Cr/CrN type, consisting of chromium and chromium nitride, formed on the surface of alloy tool steel by the Arc-PVD method. Investigations of the morphology and microstructure of hybrid coatings, as well as of their phase composition were carried out. The studies on mechanical properties included tests on hardness and Young’s modulus using the nanoindentation method. Tests on adhesion were conducted using the scratch-test method. Tribological properties of the obtained coatings were evaluated by the pin-on-disc method. Resistance to corrosion was determined by electrochemical methods. It was shown that hybrid coatings of the Cr/CrN type are characterized by good adhesion to the substrate and very good tribological properties, as well as by very good resistance to corrosion in a solution containing chlorine ions.

This paper presents the results of research of Ni/diamond composite coatings produced by electrochemical reduction method. Research was focused on composite coatings with nickel matrix and diamond as a disperse phase and for comparison purposes on nanocrystalline nickel coatings. Ni/diamond composite coatings were produced in baths with different content of nanodiamond powder. The structures of the dispersed phase and the composite coatings were analysed by using X-ray diffraction, scanning electron microscopy and light microscopy. Measurements of selected properties of the coatings were performed, including roughness, microhardness, adhesion and abrasive wear resistance. The research results indicate that the produced coatings have a compact structure and good adherence to steel substrate. Moreover, nanocrystalline Ni/diamond composite coatings exhibit greater hardness and reduced abrasive wear resistance compared to nanocrystalline nickel coatings.

Underwater steel structures require periodic maintenance. In the case of vessels, anti-corrosion works are carried out in the shipyard, where very good conditions for applying organic protective coatings can be provided. Very good surface preparation can be obtained by the use of abrasive blasting. The well-prepared metal surface is free from impurities (particularly inorganic salts). Suitable conditions for the application and renovation of coatings are also ensured (creating appropriate climatic conditions, drying the air, setting the appropriate air temperature). However, there are underwater constructions that cannot be transferred above the water level and, therefore, their conservation against corrosion can take place only under the surface of the water, which significantly hinders the execution of renovation works. In this work, protective coatings for underwater application were tested. The application of coatings on selected steel surfaces over and under the water was carried out. Physico-mechanical and electrochemical tests were carried out in order to assess the quality of the obtained corrosion protection. The possible difficulties faced when applying coatings in marine conditions were discussed.

Porous metals show not only extremely low density, but also excellent physical, mechanical and acoustic properties. In this study, Hastelloy powders prepared by gas atomization are used to manufacture 3D geometries of Hastelloy porous metal with above 90% porosity using electrostatic powder coating process. In order to control pore size and porosity, foam is sintered at 1200~1300°C and different powder coating amount. The pore properties are evaluated using SEM and Archimedes method. As powder coating amount and sintering temperature increased, porosity is decreased from 96.4 to 94.4%. And foam density is increased from 0.323 to 0.497 g/cm3 and pore size is decreased from 98 to 560 μm. When the sintering temperature is increased, foam thickness and strut thickness are decreased from 9.85 to 8.13mm and from 366 to 292 μm.

Room temperature vulcanized (RTV) silicone rubber is widely used to prevent pollution flashover with its excellent hydrophobicity and hydrophobicity transfer. However, RTV coatings are at the risk of deterioration and failure in heavily polluted operating environment. In this paper, RTV coated insulators with different suspension heights operating in coal ash polluted areaswere sampled. Pollution degree, pollution composition and aging degree of coatings were tested. The result shows that the insoluble pollution contains Al(OH)3 filler precipitated from RTV coating, which indicates the aging of the RTV coating. The top surface coating is more affected by ultraviolet and rainwater than the bottom surface resulting in more serious degradation. As the pollution degree of the lower phase insulator is heavier than that of the upper phase insulator, the erosion effect of pollution on the RTV coating is more intense. The fillers and rubber molecules of RTV continuously precipitate into the pollution layer, leading to further aging. Therefore, the overall aging degree of the lower insulator coating is more serious than that of the upper insulator coating.

In article a two-dimensional photonic crystal (PhC) is considered and modelled as a new generation antireflection coating for optoelectronic devices. Traditional antireflective coatings (ARCs) reduce the reflection of the radiation only – the new generation of antireflective coatings should affect the distribution of the radiation also. Such functionality can be provided by the two-dimensional PhC which reduce the reflection and scatter transmitted light. Prior to the fabrication, the PhCs should be designed and analysed. Results of the analysis should provide quantitative means for choice of materials and design solutions. In work, we analyse the electromagnetic field distribution as Poynting vectors inside the materials of optoelectronic devices, in order to investigate the possibility of improving the construction of future optoelectronic devices. Furthermore, we calculate the reflection and transmission of that ARC. It’s a complex optic analysis of new generation of ARC. The numerical analysis has been performed with the FDTD method in Lumerical Software. In work, we consider the two-dimensional photonic crystal on the top surface of optoelectronic structures. We compared the results with the traditional ARC from these same parameters as PhC: thickness and material. As an example, we presented the application of modelled, photonic crystal, thin-film, GaAs solar cells with PhC on top. The efficiency of this solar cell, using the photonic crystal, was improved by 6.3% over the efficiency of this same solar cell without PhC. Thus, our research strongly suggests that the unique properties of the photonic crystal could be used as a new generation of ARC.

To obtain anti-corrosive thermo-diffusion zinc coatings, the authors use highly effective zinc saturating mixtures. This technology makes it possible to obtain coatings with a high zinc content in the δ-phase as well as a zinc-rich phase of FeZn13 (ζ-phase) on the coating surface. As a result of long-term studies into the corrosion properties of thermo-diffusion zinc (TDZ) coatings conducted by the authors, a number of features of their corrosive behavior have been established. The corrosion rate of those coatings in desalted and chloride-containing media is lower than those of galvanic or hot-dip zinc coatings. The corrosion behavior depends on the content of zinc on the surface and the texture features of the coating. The results showed that on the surface of thermo-diffusion coatings in the corrosion on media containing chloride ions, zinc hydroxychloride (simonkolleite – Zn5Cl2[OH]8[H2O]) has been formed. Compared to coatings obtained by other methods, the rate of simonkolleite formation was higher on TDZ coatings, which might have a positive effect on their resistance in aggressive atmospheres.

Electrochemical Cr coatings doped with diamond nanoparticles were deposited on sintered steels with different carbon contents (0.2-0.8 wt.-%). The mechanical properties of surfaces as hardness and wear resistance increase as compared to the steel substrate. Microcutting and microgridding mechanisms were observed after tribological tests, but also adhesive wear in some areas was observed. X-ray examination indicated that the layer was textured, with the exception of the sample with the highest concentration of diamond nanoparticles in the electrolyte (42 g/l). The intensity ratio ICr110/ICr200 was calculated and compared with the indices for a standard sample. The greatest differences in the intensity ratio occurred for the samples with low carbon content (0.2%C). On the other hand, more the material is textured the greater the difference.

Detection and identification of toxic environmental gases have assumed paramount importance precisely in the defense, industrial and civilian security sector. Numerous methods have been developed for the sensing of toxic gases in the environment ever since surface acoustic wave (SAW) technology came into existence. Such SAW sensors called electronic nose (E-Nose) sensor use the frequency response of a delay line/resonator. SAW device is focused and given importance. The selective coating between input and output interdigital transducers (IDTs) in the SAW device is responsible for corresponding changes in operating frequency of the device for a specific gas/vapour absorbed from the environment. A suitable combination of well-designed SAW delay lines with selective coatings not only help to improve sensor sensitivity and selectivity but also leads to the minimization of false frequency alarms in the E-Nose sensor. This article presents a comprehensive review of design, development, simulation and modelling of a SAW sensor for potential sensing of toxic environmental gases.