Post-secondary-school migration of young people to large regional centres as a factor of depopulation and disharmonious regional development in Poland

Purpose: The purpose of this article is to demonstrate that the youth internal migrations are not, as is generally accepted, temporary, in order to obtain an education, but permanent in the final intention. Design/Methodology/Approach: The survey were carried in two different regions: one with a strong (large) regional center and the other with the weaker (smaller) center. In those region secondary education centers of various sizes were selected. There were conducted an auditorium survey among 2380 young people graduating from general secondary schools. The basis of the study was a survey containing several questions and determining five features related to background legal data. Findings: Education migrations "to study" become the beginning of the final emigration addressed to the metropolitan city as a large academic center. The research results also proved that the process of draining small regions centers by large regional centers leads to a deepening of differences in the development of regions, especially their capitals. Practical Implications: The results of analysis might be used in shaping an appropriate development policy. They may also indicate the need for more than proportional support for small regional capitals or - looking from a different perspective - to real processes of the territorial division of the country. Originality/Value: Research results can contribute to the construction of theoretical models regarding migration and local and regional developmentpeer-reviewe

Prediction of the chemical composition of combustion products in metallurgical heat furnaces with numerical methods use

In this paper the results of numerical calculations of chemical composition of flue gases, produced bycombustion of natural gas, were presented. Calculations were conducted for metallurgical pusher furnace,working in one of the steelworks located in Poland. The chemistry of combustion process was modeled usingthe program CHEMKIN-PRO. Simulations of the chemical composition of flue gas, in various zones of thefurnace, were carried out based on the measurement data collected from the real object

The control of NOx concentration in natural gas combustion process

W artykule podjęto problematykę formowania tlenków azotu w procesie spalania gazu ziemnego przy zmiennej wartości stosunku nadmiaru powietrza i temperatury. Wymienione parametry odgrywają bowiem istotną rolę w powstawaniu NOx, o czym świadczą zaprezentowane wyniki badań oraz liczne publikacje. Kontrola tych parametrów pozwala ograniczyć ilość formowanych tlenków azotu. W ramach badań przeprowadzono eksperyment laboratoryjny oraz obliczenia numeryczne, mające na celu określenie wpływu stosunku nadmiaru powietrza i temperatury na udział NOx w spalinach. Pomiaru stężenia NOx dokonano w piecu elektryczno-gazowym za pomocą analizatora Testo 350. Przeprowadzono też symulacje komputerowe z wykorzystaniem programu CHEMKIN. Otrzymane wyniki badań doświadczalnych i modelowych przedstawiono graficznie oraz dokonano ich analizy porównawczej.Article discusses the problem of nitrogen oxides formation during the natural gas combustion with variable excess air factor and temperature. These parameters play an important role in the NOx formation, as evidenced by present results of research and numerous publications. control of these parameters allows to limit the amount of formed nitrogen oxides. The purpose of this study was to determine the effect of excess air factor and temperature on the part of NOx in the exhaust. Research consisted of conducting laboratory experiments and performing numerical calculations. NOx concentrations were measured in the electric- gas furnace using gas analyzer Testo 350. Furthermore, computer simulations were carried out using the program CHEMKIN. The obtained experimental and model results were presented graphically and there was made a comparative analysis

The Optimization And Diagnostics Of Combustion Process With Numerical Modelling Application

The progressing development of industry and the associated rising environmental pollution create the need for the intensification of combustion processes and the implementation of increasingly stringent environmental protection standards. Therefore, an intensive progress in scientific and research work that is lately observed and studies with the use of numerical methods, are becoming an indispensable element of experimental research. This allows for: optimization of combustion processes, development of new designs of burners and technologies of low-emission combustion, as well as prediction of ecological effects. This article presents the possibilities of numerical modelling in combustion processes in heat furnaces. The chemistry of the combustion process was modelled in CHEMKIN software, while the dynamics of flue gas flow in the combustion chamber was modelled with the use of FLUENT software. Numerical computations were performed for both, the experimental chamber and the real objects, i.e. a pusher furnace and a sheet hardening furnace. The results of obtained measurements and numerical calculations clearly show that the use of hot air affects the growth of emissions, in particular NOx. Furthermore, it has also been proved that the design and the appropriate location of the lance supplying the secondary air result in the reduction of emissions of nitrogen oxides

The coal combustion in oxygen-enriched atmosphere as the way to reduce carbon dioxide emissions

W artykule, opierając się na przeglądzie literatury oraz obliczeniach analitycznych i numerycznych spalania węgla kamiennego, przedstawiono wpływ atmosfery utleniającej na tworzenie się CO2 w spalinach. Wyniki obliczeń przedstawiono graficznie i dokonano ich analizy. Przeprowadzona analiza wykazała, że spalanie węgla w powietrzu wzbogaconym tlenem prowadzi do wzrostu koncentracji CO2 w spalinach, co pozwala na jego ograniczenie w drodze sekwestracji.This paper presents the impact of the content of the gas atmosphere on the concentration of carbon dioxidein flue gasbased on literature review and numerical and analytical calculations. The obtained results were presented graphically and there was made a comparative analysis. The research results prove that the coal combustion in oxygen-enriched atmosphere leads to CO2 concentration in flue gas increase, what allows to its reduction by the sequestration

Torgas condensate combustion in the SI engine

The article presents results from IC engine tests on combustion of alcohol fuel with the addition of torgas condensate. Torgas is a by-product created from the torrefaction of Sida hermaphrodita. It was obtained from torrefaction carried out at a temperature of 400°C. Torgas was condensed in a tubular cooler. The basic fuel was butanol. This fuel was chosen, because regular hydrocarbon based fuels got delaminated while blended with torgas condensate. The condensate dissolves in alcohol therefore the choice was justified. In the mixture, the volume ratio of alcohol to condensate was 4:1. The combustion was carried out in a spark-ignition, single-cylinder engine with a cubic capacity of 650 cm3. The engine was able to vary its compression ratio. The engine worked at full load at maximum open throttle. The engine body was heated to a temperature of 95°C and this temperature was maintained throughout the testing period. The engine was running at 850 rpm. The first stage of the experiment included determination of the optimal ignition angle for butanol as a reference fuel and for a mixture of butanol and torgas condensate. The optimal spark angle was estimated based on the maximum indicated work. Three compression ratios, i.e.: CR=8.8, 10 and 11.2 were used. All tests were performed for a stoichiometric air fuel ratio. The obtained in-cylinder pressure diagrams for the reference fuel and the fuel with the addition of condensate were compared with each other. The rate of pressure increase inside the cylinder was calculated. For all tests, the following exhaust components were measured: CO2, CO and HC

The Analysis of Nitrogen Oxides Formation During Oxygen - Enriched Combustion of Natural Gas

This paper presents the study of oxygen–enriched combustion of natural gas and its impact on nitrogen oxides emission. The research were performed on two experimental stands, i.e. combustion chambers with an industrial swirl burner of maximum power equal to 90 kW and 10 kW. The investigation includes the influenced of oxygen enhanced within the range between 21% and 30%. Furthermore, the role of temperature during the oxygen enrichment was analysed. The results of the research showed that with the rise in oxygen concentration in the air the concentration of nitrogen oxides also increases what is directly related to the rise in flame temperature as well as the addition of oxygen

Application of computational techniques to model the safe operation of industrial heating chamber

Szczególnym rodzajem zagrożeń możliwych do wystąpienia na terenie wielu zakładów przemysłowych (np. na terenie huty) są zagrożenia związane z obecnością niebezpiecznych substancji, w tym gazów palnych, takich jak gaz ziemny czy gaz koksowniczy. Niewłaściwe spalanie tych gazów w komorach grzewczych może być bezpośrednią przyczyną niekontrolowanego uwalniania się szkodliwych dla zdrowia i życia substancji, takich jak tlenek węgla czy niedopalone węglowodory. Sytuacja jest szczególnie niebezpieczna w przypadku nadciśnienia w komorze grzewczej, ponieważ wiąże się to z „wybijaniem spalin”, tzn. uwalnianiem się produktów spalania paliwa na zewnątrz, co może być przyczyną zatrucia organizmu. Ze względu na powyższe, w niniejszym artykule przedstawiono możliwości wykorzystania techniki obliczeniowej do prognozowania zagrożeń związanych ze spalaniem paliwa gazowego w komorze grzewczej, a mianowicie w piecu przepychowym do nagrzewania wsadu metalowego. Zaproponowana metoda przewidywania składu chemicznego spalin umożliwia odpowiednią kontrolę procesu spalania, zmierzającą do zmniejszenia negatywnych skutków zarówno środowiskowych, jak i zdrowotnych.A special type of threats possible to occurre in many industrial plants (eg. at the smelter) are risks associated with the presence of hazardous substances, including flammable gases, such as natural gas and coke oven gas. Improper combustion of these gases in the heating chambers may be a direct cause of the uncontrolled release of harmful substances for health and life, such as carbon monoxide and unburned hydrocarbons. The situation is particularly dangerous in the case of overpressure in the heating chamber, because it involves the "knocking out of flue gas", i.e. release of combustion products on the outside, which can cause poisoning of the human body. Due to the above, in this paper the possibility of using computer technology to predict the risks associated with the combustion gas in the heating chamber, namely in the pusher furnace to heat the metal charge was presented. The proposed method of predicting the chemical composition of flue gas allows to proper control of the combustion process, in order to reduce the negative effects of both environmental and health problems