Overview of the local government powers in the field of the environment protection: the European experience

The article analyzes the environmental competence of local governments of leading European countries. It is noted which powers of the municipal government in the field of environmental protection were transferred to the local level due to decentralization. Positive aspects are highlighted, which can be further used by national local governments. In view of the above, it is obvious that in Ukraine, in order to increase the efficiency of local self-government bodies in the environmental sphere, it is necessary to more clearly define the functions and powers and their responsibility for decision-making. It should also be noted that there is a lack of harmonization of regulations in this area at the local, regional and state levels. The result is duplication of functions and disputes beyond authority. European experience shows the expediency of expanding the competence of local self-government in the field of environmental protection and a clear definition of the powers of municipal authorities

Constitutional and Legal Basis of Territorial Organization Public Authorities in the Countries of Central and Eastern Europe

The article is devoted to the study of the constitutional and legal basis of the public authority territorial organization in the countries of Central and Eastern Europe. The legal framework governing regional and local government is described, in particular, attention is focused on the structure of the regulatory basis of municipal government, it is determined that the main source in the formation of legislation in the field of local government was the European Charter of Local Self-Government. In addition, the system of territorial organization of regional and local authorities, which was formed as a result of the reform of the administrative-territorial structure in the early 2000s, taking into account the European requirements of NUTS, is covered

Building on polish experience of local self-government development in Ukraine as a form of cooperation between countries

The article considers some aspects of the Polish experience of reforming local self-government and administrative-territorial organization. The historical reasons for the development of the institute of local self-government in Poland are analyzed, its legal basis, the competence of local self-government bodies is characterized, in particular, the main powers of the commune council and county council are determined. The peculiarities of the administrative-territorial structure of Poland in the aspect of the possibility of borrowing experience of territorial transformations are determined

Oxidation-Induced Phase Transformations and Lifetime Limits of Chromia-Forming Nickel-Base Alloy 625

For its high creep resistance the commercial nickel-base alloy 625 relies on solid solution strengthening in combination with precipitation hardening by formation of delta-Ni3Nb and (Ni,Mo,Si)6C precipitates during high-temperature service. In oxidizing environments the alloy forms a slow growing, continuous chromia layer on the material surface which protects the alloy against rapid oxidation attack. The growth of the chromia base oxide scale results during exposure at 900–1000°C in oxidation-induced chromium depletion in the subsurface zone of the alloy. Microstructural analyses of the cross-sectioned specimens revealed that this process results in formation of a wide subsurface zone in which the mentioned strengthening phases are dissolved, in spite of the fact that both phases do not contain substantial amounts of the scale-forming element chromium. The cross-sectional analyses revealed that, in parallel to the formation of a precipitate depleted zone, a thin, continuous layer of niobium-rich intermetallic precipitates formed in the immediate vicinity of the scale/alloy interface. The Subsurface Phase Enrichment (abbreviated as SPE) was shown to be the result of an uphill-diffusion of niobium, i.e. the element stabilizing the strengthening precipitates delta-Ni3Nb, in the chromium activity gradient and is thus a natural consequence of the oxidation-induced chromium depletion beneath the chromia scale. The thermodynamic calculations carried out using the Thermo-Calc/DICTRA software packages revealed that in alloy 625 the chemical activity of niobium decreases with decreasing chromium content. As chromium is being continuously removed from the alloy as the result of the chromia scale growth, the zone of lowest Nb-activity is formed in the location with the lowest chromium concentration, i.e. the scale/alloy interface. This creates a driving force for Nb to diffuse towards the scale/alloy interface against its own concentration gradient, which is known in literature as uphill-diffusion phenomenon. Also the M6C carbide is found to dissolve in the subsurface zone during high-temperature oxidation of alloy 625 although chromium is only a minor constituent in this (Ni3Mo3)C base carbide The thermodynamic calculations revealed the carbide dissolution to find its cause in the increasing carbon activity with decreasing chromium content which forced carbon to diffuse back from the subscale zone towards the bulk alloy resulting in carbide dissolution beneath the chromia scale. SPE is experimentally found to be substantially less pronounced in thin foils than in thick specimens of alloy 625. It could be shown that this effect is related to the smaller reservoirs of the scale-forming element chromium as well as that of the delta-Ni3Nb phase stabilizing element niobium in the thin specimens. As the thinner specimens (thickness in the range of 0.1 mm) become more rapidly depleted in chromium resulting in flatter chromium depletion profiles, a smaller driving force for uphill-diffusion of Nb towards the scale/alloy interface leads to a substantially less pronounced delta-phase enrichment/depletion than in specimens of a few mm thickness. Decreasing specimen thickness suppresses the enrichment/depletion process of the delta-Ni3Nb phase and results in complete dissolution of the M6C carbide after longer exposure times. SPE is not observed during oxidation of extremely thin-walled specimens, e.g. extremely thin foils or metal foam particles fabricated from alloy 625. During high-temperature oxidation of metal foams consisting of e.g. 20-60 µm diameter particles, the delta-Ni3Nb phase enrichment at the scale/alloy interface does not occur and can thus be virtually ignored when modelling the oxidation-induced lifetime limits of alloy 625 metal foams. The lifetime prediction based on the finite-difference calculation of the chromium depletion at the metal/oxide interface of a spherical metal foam particle showed a parabolic dependence of the time to breakaway from the foam particle radius. The predicted lifetimes were found to be in good agreement with the experimental results. A new analytical lifetime model to predict times to breakaway of thin-walled components (foils, wires, metal foams, etc.) was developed as an extension of the available lifetime models. The lifetime model derived is a simple mathematical expression which is able to substitute conventional robust equations thus making the lifetime prediction less time consuming and more efficient. The simplified lifetime treatment shows excellent agreement with the conventional lifetime models and is also in good agreement with the experimental breakaway results for alloy 625 metal foams

Некоторые особенности использования модели Гордона при оценке бизнеса

Generally accepted conditions of Gordon model using are analyzed. Specificity of the model application to net operation income and free cash flow to the firm is considered. The matter about using the model to nominal income measurer is discussed. Growth rate difference of revenue and free cash flow is demonstrated.Проанализированы общепризнанные условия использования модели Гордона. Рассмотрена специфика применения модели к чистому операционному доходу и чистому денежному потоку для инвестированного капитала. Обсужден вопрос об использовании модели применительно к измерителям дохода в номинальном выражении. Показано отличие темпов роста чистого денежного потока и дохода от реализации.Проанализированы общепризнанные условия использования модели Гордона. Рассмотрена специфика применения модели к чистому операционному доходу и чистому денежному потоку для инвестированного капитала. Обсужден вопрос об использовании модели применительно к измерителям дохода в номинальном выражении. Показано отличие темпов роста чистого денежного потока и дохода от реализации

A Simple Expression for Predicting the Oxidation Limited Life of Thin Components Manufactured from FCC High Temperature Alloys

Chromia and alumina forming high temperature alloys suffer from breakaway oxidation if the concentration of the preferred scale forming element in the alloy decreases below the level required to sustain growth of the protective oxide scale. In thin components, the breakaway may occur even before oxide spallation starts to contribute to alloy depletion. In the present paper a simplified method is developed to predict the time to breakaway as a function of oxidation rate, initial concentration and diffusivity of the scale forming element in the alloy as well as component thickness. The first approach used is an approximation of the analytical solution previously derived by Whittle. The second method is based on a numerical solution and an exploration of the way in which the time to breakaway varies with the above mentioned parameters. Comparison with literature data reveals that for a number of applications good agreement between calculated and measured lifetimes can be achieved using both approaches. The lifetime equation derived using the numerical approach has the advantage that it allows prediction of breakaway oxidation in a larger range of experimental and alloy composition related parameters. It not only describes the behaviour of materials with a face centered cubic lattice but also includes the limiting case in which solute diffusion is fast compared to surface recession rate, as in, for example, the oxidation of ferritic alumina forming FeCrAl alloys at high temperatures