Influence of mitosporic fungi upon zinc-polymeric coatings on steel under the different environment

Zinc-polymeric coating samples were exposed to different environmental conditions (for 2 years): marine – dunes on the shore of the Baltic Sea (Neringa), rural-agrarian district of Moletai and the industrial zone of Vilnius. During the whole period of the study 94 species of fungi, were isolated from the exposed samples of zinc-polymeric coating on steel. The zinc-polymeric coatings exposed to marine and rural-agrarian environments were deteriorated most markedly. A scanning electron microscope (SEM) was used to characterize the morphology of the surface. The phase composition of the zinc-polymeric coatings on the steel substrate was analysed by an X-ray diffractometer (XRD). The products formed on the zinc-polymeric coatings were detected by a Fourier transformation infrared spectrometer (FTIR). The effect of environmental conditions on the mass change of the samples was determined by the standard dissolution method. First published online: 08 Feb 201

Evaluation of Heavy Metals Amount in the Lithuanian Soils Near the Zone of Transport Pollution

Vytauto Didžiojo universitetasŽemės ūkio akademij

Investigation of Non-abrasive Antifrictional Surface Finishing

Santr. liet. žrn. galeBibliogr.: p. 57 (8 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Geležinkelio transporto teršiamų dirvožemių metodologiniai tyrimai

Santr. anglBibliogr.: p. 131 (5 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Application of the new physical chemical methods in soil ecological investigations

Bibliogr.: p.133 (3 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Natūralios ir eksperimentinės sunkiųjų metalų sorbcijos tyrimai pakelių išplautžemiuose

Bibliogr.: p. 104 (10 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

Tribological properties of lubricant additives of Fe, Cu and Co nanoparticles

Tribological investigations were performed on mineral oil containing Fe, Cu and Co nanoparticles and their combinations. The tribological tests showed that each set of nanoparticles significantly reduced the friction coefficient and wear (up to 1.5 times) of friction pairs. The use of Cu nanoparticles provides the most effective reduction of friction and wear in each combination of nanoparticles. Surface analysis shows that the constituent elements of nanoparticles precipitated on the contact surface during the use of the oils with nano-additives. Different structures formed on the friction surface are observed in the contact zone and over the remainder of the ball surface. The SEM micrographs and EDX chemical analysis confirm the formation of a tribo-layer composed of the elements from the nanoparticlesVytauto Didžiojo universitetasŽemės ūkio akademij

Photoluminescence Properties of Porous Silicon with CdSe/ZnS Quantum Dots

In this work we have produced visible light emitting quantum dots (QD) of CdSe/ZnS and precipitated them onto the surface of porous silicon structure. Combining basic materials, such as porous silicon, with nanoparticles enables producing of low-cost light emitting materials, what is economically useful and important nowadays. The porous silicon (PS) structures were prepared from 5&nbsp;min to 60&nbsp;min by chemical etching at room temperature in HF&nbsp;:&nbsp;HNO3 solution and cleaned in the H2SO4&nbsp;:&nbsp;H2O2 mixture. The structures of PS and PS-QD were investigated by SEM and UV-VIS spectroscopy. Absorption and photoluminescence of the samples, were measured in the near UV and visible spectral region. Two peaks of photoluminescence of PS-QD at 550&nbsp;nm and 682&nbsp;nm were found and different increase of photoluminescence intensity of these peaks depending on excitation wavelength was detected and discussed.http://dx.doi.org/10.5755/j01.ms.17.3.585</p

Influence of biological factors in aging of polymeric materials under natural environmental conditions

Two copolymers were investigated for long-term influence of environmental factors. The polymers were exposed in the open air, in a special containers kept in the open air and in damp cellar. Microbiological evaluation of the exposed materials showed that these copolymers were contaminated by micromycetes. Scaning electron microscopy allowed to observe abundant fungal growth with well developed hypha, spore producing structures and formed colonies. As these polymers are hardly available for fungi, their development was possibly determined by outer nutritional and energy sources – pollutants settled on the materials. The heaviest contamination of the materials was noticed in cellar conditions where constant high humidity prevailed. IR spectroscopy of the materials showed that tetrafluorine ethylene and hexafluorine propylene copolymer kept in the open air and containers did not undergo structural changes. Meanwhile, IR spectrum of the sample exposed in cellar, showed high changes in structure. The results allow to conclude that microorganisms could have an effect on materials deterioration and destruction processes.Structural changes of the copolymer of tetrafluorine ethylene and vinylidene fluoride were observed after exposure of its samples in the open air, where all environmental factors influenced, and in the cellar, where combined effect of humidity and microorganisms took place

Исследование натуральной и экспериментальной сорбции тяжелых металлов в придорожных лювисолях Литвы

Santr. rusBibliogr.: p. 118 (11 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij