REVIEW OF AIR POLLUTION RESEARCH RESULTS ON THE EXAMPLE OF TBILISI
Background: Air pollution is one of the significant environmental challenges facing modern humanity. Atmospheric air is polluted with harmful substances emitted from anthropogenic and natural sources. Aim: The presented paper provides an overview of monitoring results conducted in the Capital of Georgia for 2023. Results from air quality monitoring sensors show that particulate matter, sulfur, and nitrogen dioxide represent problematic pollutants in different city areas. Methods: The research was carried out through sensors installed in different districts of Tbilisi. The investigation was carried out within the NATO SPS program project REACT. Results: Atmospheric air pollution was monitored at four stationary sensor sets on K. Cholokashvili, Nutsubidze Street, Chavchavadze Avenues, and the Old Tbilisi area. The results are presented in the article in the form of tables. Discussion: Average indexes of sulfur dioxide and PM particles were observed in all areas. Nitrogen dioxide indices were both low and medium. Conclusions: Based on the data obtained, it can be assumed that the air in most districts of Tbilisi is moderately polluted, and in some cases, the data exceeds the maximum allowable norm. There may be several reasons for this.: 1. Unauthorized slashing of Green islands and massive construction of high-rise residential buildings on their place in Tbilisi. 2. Malfunctioning vehicles, the technical inspection of which has recently been made stringent. However, some vehicles still pollute the air. 3. Emissions produced by mini factories and enterprises.
Read ArticleCOMPARISON OF TWO STAINING METHODS FOR ANODIZING IN ALLOY 6063 ALUMINUM PROFILES
Background: Aluminum stands out for being a light, corrosion-resistant, and recyclable metal, achieving wide coverage in the market. When incorporated into alloying elements, it is possible to acquire other desirable characteristics. Alloy 6063, intended for architectural purposes, has aesthetic, structural, and strength functions. Anodized finishing is performed through an electrolytic process, ensuring a more resistant aluminum oxide film than that formed naturally. For decorative purposes, the anodic film coloration can be performed by several methodologies, in this case, for the coloration by organic adsorption, with the use of aniline, and the electrolytic coloration, composed of tin sulfate salts, both for obtaining the black color. Aim: Compare of two different staining methods on the surface of anodized profiles of aluminum alloy 6063. Methods: Profile samples were collected and tests were carried out to measure the thickness of the anodic layer, immersion tests with 3,5 percent sodium chloride, for 1000 hours, and neutral saline mist, for 600 hours. Results and Discussion: Both methodologies proved to be resistant to immersion tests with sodium chloride, as well as with neutral saline mist, and these tests are quite aggressive and provide corrosion of the material when not well treated. Corrosion points were only seen at the intersections performed, and in the rest of thearea, no points were detected. Conclusions: The result of both methodologies was positive, considering tht there was no corrosion in the tested samples, except in the intersections performed, as well as the maintenance of the color in both tested methodologies, which was not expected in the literature. For future work, it is suggested to deepen the study to perform electrochemical impedance spectroscopy tests for exaluate the strength of the anodic film and perform anodizing with the same parameters, however, with different anilines to analyze their behavior.
Read Article(Cu0.4Al0.3)TaSe2: PREPARATION AND CRYSTAL STRUCTURE ANALYSIS FROM X-RAY POWDER DIFFRACTION
A new phase of the (CuAlSe2)1-x(TaSe)x alloy system was synthesized by the melt and annealingtechnique and studied by SEM, DTA, and XRPD techniques. Its structure has been refined by the Rietveld methodusing X-ray powder diffraction data. The new alloy corresponds with the stoichiometry Cu0.4Al0.3TaSe2. Thiscompound crystallizes in the hexagonal space group 𝑃6ത𝑚2 (Nº 187) with a MoS2-type structure, and unit cellparameters a = 3.455(2) Å, c = 13.423(4) Å, V = 138.7(1) Å3, Z =2. The crystal structure is based on the MoS2-type of stacking of TaSe2 layers with a partial ordering of Cu and Al cations over the tetrahedral sites. The powderpattern was composed of 63.1% of the principal phase Cu0.4Al0.3TaSe2 and 29.9% of CuAlSe2, 7.0% of TaSe3, asthe secondary phases.
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