Supplement to the paper “Groundwater dynamics between Planinsko Polje and springs of the Ljubljanica River, Slovenia” from Blatnik et al. (2019) published in Acta Carsologica 48/2

The article of Blatnik et al. (2019) “Groundwater dynamics between Planinsko Polje and springs of the Ljubljanica River, Slovenia” published in Acta Carsologica, 48/2 focused on describing the hydrogeological behaviour of the aquifer between Planinsko Polje and the springs of the Ljubljanica River. The authors analysed the effect of different high water events that occurred between January 2015 and May 2018. Interpretations were based on hydrographs obtained by continuous measurements of water level, temperature and specific electric conductivity in selected ponors, springs and water active caves located in the area between Planinsko Polje and the springs of the Ljubljanica River. Through these interpretations, different conceptual hydrological models about the dynamics and directions of the flow in the aquifer have been proposed and tested. A flow connection was proposed between the Hrušica Plateau, estavelles located at the NW border of Planinsko Polje, and caves Gradišnica (W2) and Gašpinova Jama (W3) close to town Logatec. In this supplement, we provide new data recorded during an unusual hydrological event in August 2018. These further support and stress the importance of the connection between the Hrušica Plateau and Logatec region (W2 and W3).

Relationship of the s1-elements halogenides melts specific electric conductivity with alkali metals specific electric conductivity

The paper presents an analytical description of the relationship of the specific electrical conductivity æ of individual alkali metals haloganides melts (MHal) (M – Li, Na, K, Rb, Cs, Fr; Hal – F, Cl, Br, I) and the specific electrical conductivity æ(M) of alkali metal melts for temperatures (Тпл + n) (Tпл – melting temperature K; n = 5, 10, 50, 75, 100, 150, 200° higher melting temperatures of MHal and metals) and the specific electrical conductivity of alkali metals at standard temperature using M.Kh. Karapetyans comparative methods. The relationship of properties æ(MHal при Тпл+n) = f(æ(MHal при Тпл+5)), æ(FrHalТпл+n) = f(æ(FrHalТпл+5°)) is described in the "property-property" coordinates. A comparative analysis of the specific electrical conductivity values of francium haloganides melts obtained by the proposed methods was carried out. The possibility of calculating the electrical conductivity of molten salts from the electrical conductivity of molten metals is shown. It is shown that the equation æ(MHal)0.5 = a + bæ(M)1.5 can be used to calculate the specific electrical conductivity of francium haloganides melts. The calculation of the specific electrical conductivity using various equations shows the consistency of the numerical values obtained.

Analytical description of sodium halogenides melts specific electric conductivity and its calculation for sodium astatide melt

The paper presents analytical and graphical dependences of the individual haloganides melts specific electrical conductivity æ of the sodium NaHal series (Hal – F, Cl, Br, I) on the halogen order number Z, ionic radius r of haloganide-ion Hal–, halogen ionic potential 1/r, reduced ionic radius r/Z, difference of electronegativity (∆χ = χ(Hal) – χ(Na)): æ = f(Z); æ = f(r); æ = f(1/r); æ = f(r/Z); æ = f(∆χ) for the temperature higher melting temperatures on 5, 10, 50, 75, 100, 150 и 200°. M.Kh. Karapetyans сomparative methods were applied for the description. The minimum standard deviation and maximum correlation coefficient corresponds to the equation æ–1 = a + bexp1/r, according to which the numerical values of æ(NaAt) are calculated for real temperatures. The temperature dependence æ of the NaAt melt is described by the equation æ = 0.0508+0.0023Т. A comparative analysis of the relationship between the specific electrical conductivity of NaHal melts at a temperature of Tm + n (n = 10 ... 200° higher the melting temperature) and æ at (Tm + 5°). A comparative analysis is represented by straightforward dependencies. It was shown that the specific electrical conductivity of the NaAt melt is related to the electrical conductivity of LiAt by the direct equation æ(NaAt) = 0.035+0.607æ(LiAt). The straight line equationalso relates æ of the NaHal melt (Hal – F, Br, I, At) to the specific conductivity of the NaCl melt. Between the numerical values of the specific electrical conductivity of the sodium astatide (NaAt) melt calculated by different methods, consistent data were obtained.

Analytical description of the specific electric conductivity of halogenides KHal melts and its calculation for the KAt melt

In this paper, the analytical description of the specific conductivity of the potassium halogenides melts KHal (Hal – F, Cl, Br, I) is presented. The analitical description is provided on dependence of the specific conductivity on the halogen order number ӕ = f(Z), the ionic radius of halogen-ion ӕ = f(r), the ionic potential ӕ = f(1/r), the electronegativity difference ӕ = f(∆χ) ((∆χ = χ (Hal) – χ(K)). The interrelation of a reduced property with an order number ӕ/Z = f(Z) is considered. According to the obtained analytical dependencies, the calculation of the value of the potassium astatide specific conductivity is given for temperatures above the melting point on 5, 10, 50, 75, 100, 150 и 200°, in literature Information for KAt absent. The calculation was carried out using comparative methods for calculating M.Kh. Karapetyan in the coordinates of "property-parameter" and "property-property." Least squares method was applied for processing the analytical description results with the choice of optimal dependencies on the maximum correlation coefficient and the minimum standard deviation. The analysis of the interrelation of the calculated numerical values with similar characteristics for NaAt и LiAt is presented. Comparison of the specific conductivity obtained numerical values of the astatide potassium melt showed good consistency with the values ӕ obtained from the straight line dependence ӕТпл+n = a∙ ӕТпл+5 (n = 10°…200°) and also with similar characteristics for lithium astatide and sodium astatide. The analytical calculation results allow to describe the temperature dependence of the potassium halogenides specific conductivity, including KAt. The calculation method can be used to describe the melts specific conductivity in the same type series of compounds of alkaline and alkaline-earth elements that make up electrolytes for chemical current sources.

Multi-frequency method of control for eddy current thickness measurement

When eddy-current thickness measurement is carried out, one of the disturbing factors leading to an error in determining the thickness of the conductive coating on a conducting ferromagnetic or non-ferromagnetic substrate are the variations of the electromagnetic parameters of the coating and the substrate observed when the transducer moves from point to point along the surface of the controlled product, when moving from one product to another, at presence of heat treatment or other thermal effects on the controlled product after coating. The paper presents the results of experimental studies of the influence of variations in the electromagnetic parameters of a conducting ferromagnetic substrate on the phase of the emf, introduced into the superimposed transducer. It is shown, when the minimum influence of such variations on the specified phase is achieved. As a result, it was suggested to use the multi-frequency method to reduce the influence of variations of electromagnetic parameters on the accuracy of determining the coating thickness during application of the phase control method. It consists in the fact that the frequency of the excitation current of the transducer, mounted on the monitored product, is discretely reduced from a certain maximum to a certain minimum frequency during measurements. At the high frequency, the specific electric conductivity of the coating material is taken into account, with decreasing frequency, such a value is determined when the electromagnetic parameters of the substrate begin to affect the phase formation. Then, using the calibration curve obtained from samples from the same coating material and substrate as the controlled article and having a known coating thickness, the desired coating thickness on the product to be tested is determined.

On the Measurement of Electric Resistance of Liquid Electrolytes of Accumulator Battery

Operational control of parameters of electrolytes (first of all–of specific electric conductivity), is an important electrochemical technology. The methods of measurement of electric conductivity of electrolytes is a subject of permanent discussions because of complexity of physical-and-chemical processes accompanying ion transport and of electrolyte polarization near surfaces of electrodes and of electrochemical processes on the electrodes surfaces. Actual highand low-frequency conductometric methods require relatively expensive equipment and are not free of methodological flaws. In this paper a new method of electric resistance of liquid electrolytes is described and substantiated. It is based on automatic performance of a series of measurements of electrolyte resistance at DC, data processing and extrapolation of an appropriate dependence to threshold voltage at measurement cell plates. The character of functions approximating resistance-applied voltage dependence and method of resistance determination are substantiated. The measurements of specific resistance of some electrolytes were performed. The advantages of the proposed method and measuring device are their simplicity, cheapness, reliability and, consequently, wider possibility to utilize it at technological lines and processes, even at such sites of production processes where such a control was impractical earlier. The method can be widely used for express-diagnostics of electrolytes in such areas as electrochemical energy storage, medicine, agriculture, chemical industry, food production.

REGULARITIES IN ELECTRICAL CONDUCTIVITY OF AQUEOUS SOLUTIONS OF SOME INORGANIC ACIDS

The concentration and temperature dependences of the specific electric conductivity (EC) of aqueous solutions of HCl, HBr, HNO3, HClO4, H2SO4 and HBF4, H2SiF6, and H2TiF6 were analyzed. It was shown that at a temperature of 298 K maximum specific EC of solutions of acids does not exceed the value of the limit high-frequency EC of water. The analytical equation allowing on the basis of maximum EC and corresponding to it concentration to calculate the EC of acid solutions in a wide range of concentrations and temperatures was obtained.

INFLUENCE OF FREQUENCY OF ELECTRIC CURRENT ON ELECTRIC CONDUCTIVITY OF THIN FILMS OF ELECTROLYTES

In the work the investigations of the effect of abnormally high electric conductivity of surface of the air-electrolyte interface during electrolytic decomposition of water were continued. Experiments were carried out both at alternating current via the bridge circuit and at direct current in the four-electrode cell. Previously, it was shown that in thin air-bordering electrolyte layers specific conductivity measured in the four-electrode cell during electrolysis of water exceeds the corresponding value measured with the bridge circuit for solutions of sodium hydroxide by 1.5 times, for solutions of sulfuric acid by 1.25 times and for solutions of sodium sulfate by 2.5 times. When replacing the gas-liquid interface by the liquid-solid phase one the effect disappears. It was shown that the abnormally high electric conductivity of thin air-bordering electrolyte layers depends on temperature (at 4 °С electric conductivity of 1 mm thick solution layer increases 8-12 times), ion composition, pH (maximum 5 times increase of electric conductivity corresponds to pH of isoelectric point). This allowed suggesting that such effect is caused by tunneling of charge (without mass transfer) through ordered structures on the surface of water - giant heterophase clusters. This mechanism has been called croquet. To check the influence of surface the experiments in 1 mm and 0.1 mm thick layers of electrolyte were conducted. Thin electrolyte films were stabilized by the DC-10 surfactant and the thickness was measured by interferometric methods. It has been shown that specific electric conductivity of thin films increases by 150-250 times in comparison with conductivity of the original electrolyte. This confirmed our assumptions on the nature of the effect of abnormally high electric conductivity of the gas-electrolyte interface during electrochemical generation of uncompensated H+ and/or OH- ions. Surprisingly, it appears that specific electric conductivity of the electrolyte film of thickness below 50 μm as measured at the 10 kHz alternating current is also higher than conductivity measured with the same method in the initial electrolyte volume. The values of electric conductivity of thin electrolyte films measured by different methods were almost identical. It has been suggested that this phenomenon is related to the changed conditions of charging of the double electric layer. To test the hypothesis, the values of specific electric conductivity of 1 mm thick electrolyte layer were measured at changing from 10 kHz to 0.1 Hz frequencies of alternating current. It was shown that the effect of increase in the electric conductivity begins to occur at frequencies up to 1 kHz. Calculations showed that at these frequencies the quantity of electricity transferred to the electrodes is sufficient for charging the double layer and initiation of the Faraday process. Thus, another confirmation that the croquet mechanism of electric conductivity occurs at the two conditions – the electrolytic generation of H+ or OH- ions and the transfer of charges through ordered structures on the surface of water – was found.Forcitation:Nefedov V.G., Matveev V.V., Korolyanchuk D.G. Influence of frequency of electric current on electric conductivity of thin films of electrolytes. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 2. P. 58-64

Finite-Element Simulations of a Thermoelectric Generator and Their Experimental Validation

A versatile finite-element simulation tool was developed to predict the electric power output, the distributions of the electric and entropy potentials (i.e., the absolute temperature) and the local flux densities of electric charge and thermal energy (i.e., heat) for a thermoelectric generator. The input parameters are the thermogenerator architecture (i.e., geometries of different components and number of legs) and material properties such as specific electric conductivity, Seebeck coefficient and thermal conductivity. The finite-element simulation tool was validated by modeling a commercially available thermoelectric generator, which was based on semiconducting n- and p-type Bi