An update of the macroeconometric model of the Polish economy NECMOD

The paper presents an update of the structural macroeconometric model of the Polish economy NECMOD. The updated version of the model is, similarly as its predecessor, used at the National Bank of Poland for forecasting and policy simulation exercises. NECMOD is a hybrid, medium-scale and partially forward-looking quarterly model with its structure rooted in the economic theory. Great emphasis has been put on modelling of the supply side of the economy and mechanisms that introduce high persistency of shocks. The present version of NECMOD was estimated on the data covering a period from 1995 to 2008. Its main advantage, as compared to the previous version, is a more detailed and coherent approach to the modelling of the external sector block. Now, secular changes in the exchange rate and foreign trade dynamics are explained jointly with reference to the taste-for-variety theory. Moreover, the current version of the model better reflects interdependencies between domestic and external sector, i.e. via exchange rate - wealth channel.Polish economy, macroeconometric model, macroeconomic model

Specialised Frequency Converter For Induction Devices

The article focuses on developing a frequency converter for induction surface hardening, which involves designing a device that can precisely and efficiently control the frequency of the alternating magnetic field used to heat the material. The frequency converter should be capable of operating at different frequencies, depending on the material being heated and the desired depth of penetration. Additionally, the converter should be designed to provide high power density to achieve rapid and uniform heating of the workpiece surface. Control algorithms should also be developed to ensure precise and accurate control of the induction process. Ultimately, a well-designed frequency converter can result in efficient and effective surface hardening while also prolonging the service life of the induction heating equipment

Equipment of the cold crucible for metal oxides melting

Snahou tohoto článku je představit unikátní vybavení studeného kelímku, jež umožňuje indukční tavení oxidů kovů, tzv. induction skull melting (ISM). Tavení je založeno na principu indukčního ohřevu, kdy je energie od induktoru přenášena do vsázky prostřednictvím takzvaného studeného kelímku. Tento způsob tavby umožňuje dosahovat velmi vysokých teplot taveniny (až 4 000 °C). To je umožněno tím, že na rozhraní mezi studeným kelímkem a taveninou si v průběhu tavby vytváří tavenina vlastní skořepinu (skull). Mezi touto skořepinou a studeným kelímkem přitom zároveň vzniká vzduchová mezera.This article aims to present unique equipment of a cold crucible (CC) that allows induction melting of metal oxides (the so-called induction skull melting – ISM). Melting is based on the principle of induction heating, in which energy is transferred from the inductor to the load using the CC. This method of melting makes it possible to reach very high temperatures of melt (up to 4,000 ° C). This is allowed by the fact that the melt forms its own skull crucible at the interface between the CC and the melt during melting. At the same time, an air gap is created between the skull and the CC

Vývoj kalicího stroje a inteligentního řízení

Tento článek se zaměřuje na představení vyvinutého kalicího stroje založeného na indukčním ohřevu. Tento stroj se od běžných řešení výrazně liší především rozsáhlým měřicím systémem, díky němuž máme dokonalý přehled o tom, co se během procesu děje. Dále je popsán vyvinutý řídicí systém využívající PLC. V článku je zmíněn i návrh vlastního řízení frekvenčního měniče pomocí mikrokontrolérů.This article focuses on introducing the developed hardening machine based on induction heating. This machine differs significantly from conventional solutions mainly due to its extensive measuring system, which gives us a complete overview of what is happening during the process. Furthermore, the developed control system using PLC is described. This paper also mentions the design of own control of the frequency converter using microcontrollers

Possibilities of Using an Energy Surplus of Photovoltaic Power Plants

Nowadays, the installation of photovoltaic power plants on the roof of houses is becoming more and more common. Compared to earlier times, the surplus electricity to the grid is not well-financed. It leads to increasing pressure to maximize the use of the electricity generated on the premises. Energy storage in batteries is becoming standard but is still insufficient. In most cases, the distribution of the building's consumption does not correspond to the PV generation, and the size of the battery storage would be economically prohibitive to utilize the surplus fully. A solution to this problem can be to control selected appliances depending on the PV production. This paper describes controlling the output of heat pumps, EV chargers, and resistive load. Our goal is to develop a control system for smaller buildings that allows communication between the devices and control their operation depending on the current and future PV production

Manipulation system for measuring heat flux in radioactive melt

This paper describes designing and experimental trials of an induction annealing method for AISI 321H austenitic steel wires. Specifically, it explores the feasibility of incorporating an existing frequency controller into a wire drawing line to provide induction heating of the wire stock to annealing temperatures. In-process annealing is necessary to make cold wire drawing possible by restoring the ductility of the wire stock. The reason is that the wire products are required to have strengths in excess of 1600 MPa in some cases. Hence, the only way to meet this requirement is to apply severe deformation combined with sufficiently effective polygonization

Cost reduction opportunities in induction surface hardening processes for smaller diameter cylindrical loads

This article focuses on the possibilities of improving the efficiency of induction surface hardening (ISH) processes using a specialized spray-quench device. This quench is fabricated using 3D printing, and the load is cooled by a quenching spray tangentially fed to its surface. Furthermore, the paper presents the results of several specific experiments which show how the tangential spray-quench device can influence the quenching phase of the ISH process. It is shown that the influence of the surface temperature of the load can be realized not only by the amount and type of quenching medium but also in what way the quenching medium is fed to the surface of the load

Equations, contractions, and unique solutions

One of the most studied behavioural equivalences is bisimilarity. Its success is much due to the associated bisimulation proof method, which can be further enhanced by means of 'up-to bisimulation' techniques such as 'up-to context'. A different proof method is discussed, based on unique solution of special forms of inequations called contractions, and inspired by Milner's theorem on unique solution of equations. The method is as powerful as the bisimulation proof method and its 'up-to context' enhancements. The definition of contraction can be transferred onto other behavioural equivalences, possibly contextual and noncoinductive. This enables a coinductive reasoning style on such equivalences, either by applying the method based on unique solution of contractions, or by injecting appropriate contraction preorders into the bisimulation game. The techniques are illustrated on CCS-like languages; an example dealing with higher-order languages is also shown