The effect of titanium dioxide modification on the copper powder bactericidal properties

The bactericidal and bacteriostatic effects of cop-per have been known for a long time. However, the coatings apart from biological activity should fulfil a number of other requirements, such as tightness, scratch resistance or aesthetic appearance. Researchers have been working on creating durable coatings meeting these requirements for a long time. Scientific research indicates a high interest in active coatings. Nanoscale additives are used, with the aim to modify the material’s performance at the atomic level. Composite coatings allow us to provide the materials multifunctionality, and in addition, can enhance their mutual action. There are many methods for creating such materials. One of the techniques of applying composite coatings is the Cold Spray method, in which the coating is made of a powder. The main purpose of the modification is to obtain a bactericidal and bacteriostatic effect, but also a durable and wear--resistant coating. The paper proposes modifications of copper powder with amorphous submicron titanium dioxide in order to increase its biological activity. The modified powder can be used to create coatings by various methods including thermal methods. The work presents a material analysis of Cu and TiO2powders and results of bactericidal tests carried out on a Cu-TiO2 composite powder. The experiment in-cluded Escherichia coli and Staphylococcus aureus. The studies have shown a positive effect of the addition of TiO2 on bactericidal properties against both Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) when mixed with copper at 1:9 ratio

Designing a Small Water Power Plant in Poland in the Aspect of Minimizing the Impact on River Ecosystem

A small hydro-power plant designing in aspect of current legislation is an interdisciplinary problem because of the fact that efficiency priority is not so important as ecological one. In this article the regulations concerning permissions for plant operation are discussed. The small hydro-power plant designing criteria are presented in the aspect of a plant impact on the river ecosystem

Impact of a Synthetic Component on the Emission of Volatile Organic Compounds during the Combustion Process in a Miniature Turbine Engine

This paper refers to the study of biofuel as an alternative power source for turbine aviation engines. Blends of Jet A-1 fuel and synthesized hydrocarbons from Hydrotreated Esters and Fatty Acids (HEFA) technology at different proportions, such as 25%, 50% and 75%, were used for tests. All the test results were compared with the neat Jet A-1 fuel. A miniature GTM series turbojet engine was used in the test rig studies. During the tests conducted at a specific rotational speed, selected engine operating parameters as well as the emission of volatile organic compounds were measured. In terms of engine performance, no significant differences were found between the test fuels. The results of volatile organic compound emissions indicate that among the most toxic compounds the highest concentrations were obtained for benzene. The addition of the HEFA synthetic component and increasing its proportion in the blend resulted in the obtained concentration values for benzene showing a decreasing trend. The plotted utility profile indicates that the most optimal blend, i.e., the least toxic, is the blend with the share (v/v) of 62.5% of Jet A-1 fuel and 37.5% of HEFA component

Assessment of the Actual Toxicity of Engine Exhaust Gas Emissions from Euro 3 and Euro 6 Compliant Vehicles with the BAT-CELL Method Using In Vitro Tests

Legal restrictions on vehicle engine exhaust gas emission control do not always go hand in hand with an actual reduction in the emissions of toxins into the atmosphere. Moreover, the methods currently used to measure exhaust gas emissions do not give unambiguous results on the impact of the tested gases on living organisms. The method used to assess the actual toxicity of gases, BAT-CELL Bio-Ambient-Tests using in vitro tests, takes into account synergistic interactions of individual components of a mixture of gases without the need to know its qualitative and quantitative composition and allows for determination of the actual toxicity of the gas composition. Using the BAT-CELL method, exhaust gases from passenger vehicles equipped with spark-ignition engines complying with the Euro 3 and Euro 6 emission standards were tested. The results of toxicological tests were correlated with the results of chromatographic analysis. It was shown that diverse qualitative composition of the mixture of hydrocarbons determining the exhaust gases toxicity may decrease the percentage value of cell survival. Additionally, it was proven that the average survival of cells after exposure to exhaust gases from tested vehicles meeting the more restrictive Euro 6 standard was lower than for vehicles meeting the Euro 3 standard thus indicating the higher toxicity of exhaust gases from newer vehicles

Researches on a photocatalytic device for toxic hydrocarbons removal from IC engine exhausts

Hydrocarbons, especially aromatic volatile organic compounds (AVOCs) and polyaromatic hydrocarbons (PAHs), emitted by IC engines, indisputably have a negative impact on the environment and public health. Even though current legislation strongly impacts on their low concentration in the exhausts, not quantity but the quality of those substances determines fumes toxicity. The paper presents results of the researches on a photocatalytic device dedicated to BTX (benzene-toluene-xylene) removal from IC engine exhausts, which can be applied in a vehicle cabin ventilation system. According to the results, the system is able to decrease toxic compounds concentration (caused by mobile emission sources) in inlet-air delivered to the vehicle interior. In effect, the system application reduces the users of a vehicle to exposure on contaminants