The accessibility of a law and "ignorantia juris non excusat": formal and legal aspects of legal certainty

This article is devoted to the first and most obvious requirement of legal certainty - the accessibility of a law. The subject of this research is the formal accessibility of the text of the law. The objective was to analyze the imperative of accessibility of a law in its relationship with the presumption of legal knowledge, as well as the its remedies. As a result of the study, the authors have concluded that the presumption of legal knowledge (expressed, among other things, by the maxim, ignorance of the law does not exempt from responsibility), as a condition of its existence and action, presupposes compliance with the requirement of accessibility of a law. The nature of the presumption of legal knowledge and the nullity of a legal error has been studied. Particular attention is paid to the way to ensure the accessibility of a law; in particular, the authors outline a number of problems associated with the promulgation and enactment of regulations

Light-driven nanoperiodical modulation of alkaline cation distribution inside sodium silicate glass

Chemical differentiation of atoms in the nanoscale by femtosecond laser treatment enabling the formation of periodical nanostructures (nanogratings) is demonstrated for the first time in sodium silicate glass. We report periodical redistribution of Na+ cations in SiO2 matrix related to the formation of nanogratings in 15Na2O·85SiO2 glass. They are shown to be similar to nanogratings in silica glass but their inscription is a much longer process taking 105–107 laser pulses. SEM, TEM and EDXA analysis revealed substantial migration of Na+ from the laser-irradiated area. Na+ cations remaining in nanogratings are accumulated at the boundaries or inside the 20–30 nm thick nanoplanes whereas the chemical composition of regions between the nanoplanes approaches to pure SiO2 making a drastic chemical differentiation on a nanoscale. Thus, the opportunity of optically driven nanoperiodical modulation of alkaline cation distribution inside the glass changing its properties in the nanoscale has been shown. This cation redistribution is expected to stimulate the search for new approaches to the design of complex nanostructured architectures in a glassy matrix.</p

Effect of the [U(IV)]/[U(III)] ratio on selective chromium corrosion and tellurium intergranular cracking of Hastelloy N alloy in the fuel LiF-BeF

Effect of the [U(IV)/U(III)] ratio of fuel salt on selective chromium corrosion and tellurium intergranular cracking (IGC) of Hastelloy N alloy in the LiF-BeF2-UF4 salt mixture was investigated. The chromium corrosion of Hastelloy N alloy is caused by the oxidation of chromium on the alloy surface by reaction with UF4. The tellurium IGC of Hastelloy N alloy is caused by the diffusion of tellurium along the grain boundaries with the formation of unstable tellurides with based metals and alloying additives. Results indicate that the selective chromium corrosion and the tellurium IGC of the Hastelloy N alloy in fuel salt can be controlled by the [U(IV)]/[U(III)] ratio. The tellurium IGC of Hastelloy N alloy exposed in fuel LiF-BeF2-UF4 salt can be avoided. For temperatures up to 760 °C the selective chromium corrosion can be minimized to the acceptable level when the [U(IV)]/[U(III)] ratio of fuel salt is bellow 30–40

Reduced Graphene Oxide and Its Modifications as Catalyst Supports and Catalyst Layer Modifiers for PEMFC

Reduced graphene oxide (RGO) and RGO modified by ozone (RGO-O) and fluorine (RGO-F) were synthesized. Pt nanoparticles were deposited on these materials and also on Vulcan XC-72 using the polyol method. The structural and electrochemical properties of the obtained catalysts were investigated in a model glass three-electrode electrochemical cell and in a laboratory PEM fuel cell. Among the RGO-based catalysts, the highest electrochemically active surface area (EASA) was obtained for the oxidized RGO supported catalyst. The EASA of the fluorine-modified RGO-supported catalyst was half as big. In the PEM fuel cell the performance of RGO-based catalysts did not exceed the activity of Vulcan XC-72-based catalysts. However, the addition of an RGO-O-based catalyst to Vulcan XC-72-based catalyst (in contrast to the RGO-F-based catalyst) allowed us to increase the catalyst layer activity and PEM fuel cell performance. Possible reasons for such an effect are discussed

Structural and Electrocatalytic Properties of Platinum and Platinum-Carbon Layers Obtained by Magnetron-Ion Sputtering

This article is devoted to further development of magnetron sputtering technology for catalysts and catalysts layer production for fuel cells and other electrochemical devices. Platinum-carbon films with Pt content up to 95&#8315;97 wt % were deposited using different sputtering regimes&#8212;DC (direct current) sputtering with and without application of a pulse negative bias voltage to the titanium substrate and also bipolar pulse sputtering with frequency of 10 kHz and 100 kHz. Composite platinum carbon targets were used for sputtering. Characteristics of platinum-carbon films were compared with those of platinum films deposited using the same regimes. The main methods of investigation were scanning transmission electron microscopy (STEM) with energy dispersive X-ray spectroscopy; potentiostatic and potentiodynamic methods. The catalytic activity of platinum-carbon films increased with platinum content and at a platinum concentration of 95&#8315;97 wt % became higher than that of platinum films sputtered in the same regimes. It was proposed that carbon atoms deposited on the substrate limited the mobility of the deposited platinum species and inhibited Pt cluster growth. Platinum-carbon films produced by pulsed DC magnetron sputtering with pulsed frequency 100 kHz consisted of narrow Pt columns with dome nanotops forming a well-developed surface. The porosity and specific surface of these columnar nanopillar films were higher compared with those of pure platinum films deposited under the same conditions. Moreover, the platinum-carbon films deposited using a bipolar pulse regime with a frequency of 100 kHz had the highest specific surface, porosity (30%) and catalytic activity in hydrogen and oxygen evolution due to a high ion current density and reduced pulse duration which inhibited the growth of large platinum globules

Local and Integral Techniques in Metal Compositional Analysis of Archaeological Objects with Surface Corrosion Layers and Small Sample Quantities

The paper presents the difference of three varied methods which have been used to analyze archaeological metals: X-ray fluorescence analysis – XRF (X-ray spectrometer), energy dispersive X-Ray microanalysis – EDAX (electron microscopy), and inductively coupled plasma mass spectrometry (MS-ICP). Illustrative examples of different measurements are two fragments of sickles from the hoard near the village of Sosnovaya Maza and three plates of horse harness from the treasure from the territory of the Republic of Crimea. The analysis of the results reveals the importance of formulation an individual methodology for analysis and the process of sample preparation for each measured object