The development of new methods of crop production is the most promising field of research in agriculture. There are numerous chemical techniques of seed treatment before sowing; however, mollusc mucus has not been considered as a natural alternative of seed treatment yet. In this study, we treated sweet pepper seeds with Spanish slug mucus before sowing. Seed germination success, germination time, as well as the performance of seedling growth were compared between experimental and control groups. The main result showed that seeds treated with slug mucus required significantly fewer days to germinate than seeds without treatment. Although treated seeds exhibited faster germination, seedlings showed slower growth than in the control group. No significant difference of seed germination success between the control and experimental group was found.
G K -g r a d e t r a n s f o r m e r o i l i s i n v e s t i g a t e d b y m e t h o d s o f n u c l e a r m a g n e t i c r e l a x a t i o nand Z-scanning. The size of the heterogeneous structures in the oil increases during its service. The solid-particle content in the liquid phase, however, remains essentially unchanged, and the excess particles precipitate. The feasibility of quantitative determination of the heterogeneous-structure/liquid ratio in oil samples investigated is discussed.Heterogeneous structures -colloidal, micelle-like, and solid particles -affect the properties of transformer oils (TO), and may substantially reduce the breakdown voltage, and alter the viscosity and other TO characteristics critical to power transformers, and, consequently the power systems on the whole [1, 2]. Owing to the physical and chemical processes that take place under the action of temperature, electric fields, and circulation of oil, the composition of the heterogeneous structures is altered over the life of the TO. These processes are currently being monitored by an obsolete method [3], which, in our opinion, is unreliable due to insufficient accuracy.Investigations [4][5][6][7] have indicated that heterogeneous structures always exist in TO. A method of determining the percentage of solid particles in oil products with use of nuclear magnetic (NM) relaxation is described in the literature [8]. We have been unable, however, to find information on the applicability of this method to TO. The Z-scanning method is sensitive to nonlinear optical absorption of delocalized electrons, occurring most frequently in the heterogeneous particles [9]. This study described results of TO investigation by NM-relaxation and Z-scanning methods.
During operation of the transformer, the oil in it undergoes profound changes usually referred to as aging. The electrical insulating properties of it deteriorate, and sediments accumulate on the active part, which makes it difficult to remove heat. Inhomogeneous solid formations can induce not only the voltage breakdown, but also impair the parameters such as viscosity and other char-acteristics of the oil, which are important for the reliable operation of the power transformers. Aromatic groups initially is present in the transformer oil composition during the operation of the oil, and because of the aging processes, the concentration of the unsaturated cyclic com-pounds increases. The aim of this work is to develop a new method for the determination of the aromatic compounds and colloidal particles. This goal is achieved using a visual inspection of the transformer oil samples in the visible range. The most significant result of the paper is the establishment of a correlation between the acid number of the transformer oil (KOH), the tan-gent of the dielectric loss angle and the type of oil image under the visible light illumination. The significance of the obtained results lies in the fact that the presented method based on the analy-sis of the scattered and transmitted radiation, makes it possible to determine the presence of the aromatic compounds and colloidal particles in the transformer oil, as well as to define their con-centration and size. This method simplifies the analysis of the transformer oil quality, and re-duces the cost of the research, which is an important factor for the electric power industry.
During operation, resulting from the thermochemical and electrical effects, the performance of the transformer oil decreases due to the measurement of the structural group composition. An increase in the content of the aromatic hydrocarbons leads to the appearance of a precipitate, and as well as due to its hygroscopicity, an increase in the moisture content. The latter is one of the transformer oil parameters that determines its quality. In power equipment, the presence of moisture of the order of 10 grams of water per ton of oil is allowed. At elevated water concentrations, there is a risk of the power transformers’ failure. The aim of the work was to develop new methods for determining the aromatic compounds and water contents in the transformer oil in small quantities. This goal was achieved by conducting spectral studies of the transformer oil samples in the UV range and constructing correlation lines to determine the moisture content and concentration of aromatic compounds. The most significant result of the article was the establishment of correlations between the optical density of the transformer oil in the region of 530 nm and the concentration of aromatic compounds and between the optical density in the region of 980 nm and moisture content in the oil. The significance of the obtained results lies in the fact that the optical method for determining the moisture content and aromatic hydrocarbons in transformer oils, using the constructed correlation lines, is highly accurate and does not require the use of additional reagents and complex calculations.
Moisture content is one of the parameters of transformer oil that determine its quality. This parameter is one of the most critical, which is closely monitored. During the operation of transformer oil in the power equipment of electric power systems, about 10 grams of water per ton of oil is allowed, i.e. the permissible proportion of water is 10 ppm (ppm). The aim of the work is to develop a new method for determining the permissible proportion of water in transformer oil in small quantities. This goal is achieved by performing spectral studies of transformer oil samples in the UV and visible range with the addition of cobalt (II) chloride (CoCl2) powder. Сobalt (II) chloride has the ability to change its color depending on the amount of water of crystallization. The most significant result of the article is the conclusion, obtained on the basis of the recorded spectra, about the relationship between the optical density of the spectrum in the range of 360-490 nm and the moisture content of transformer oil when adding cobalt chloride powder. The significance of the results obtained is that the authors have proposed a new optical method for determining small values of the proportion of water in transformer oils, based on the dependence of the optical properties of cobalt (II) chloride on moisture content.This method has a very high sensitivity, low cost for determining the proportion of water and is very promising for solving problems of power energy.
The service life of transformers and, as a consequence, of the electric power systems depends largely on the chemical composition and electrical insulating properties of the oil. In this regard, much attention is paid to the control of physical and chemical indicators and operational properties of transformer oils. The aim of this work is to determine the important diagnostic parameters such as the acid number and the tangent of the dielectric loss angle of the transformer oil based on the measured coordinates of the color of the transformer oil. This goal is achieved by the study of the coordinates of the transformer oils chromaticity. For this purpose, a white light source is used, which is a LED with a pumping line of 450 nm and a maximum radiation in the region of 550-560 nm, with radiation in the range from 400 to 800 nm. Sensors 1, 2, 3 allow determining the chromaticity coordinates of the measured source R, G, B (red, green, blue), due to several receivers having spectral characteristics of sensitivity in the corresponding region of the visible spectrum. The most significant result of the work was the establishment of correlations between the TM chromaticity coordinatesб their acid number and the tangent of the dielectric loss angle of TM. The significance of the results obtained was that the acid number and the tangent of the dielectric loss angle of the transformer oil could be determined by the chromaticity coordinates, and hence, by the color of the oil.
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