The Leakage of Steam Mass Flow Rate through the Gland Seals – Influence on Turbine Produced Power

In this paper is presented an analysis of gland seals operation and their influence on the performance of low power steam turbine with two cylinders and steam reheating, which can be used in marine applications. Performed analysis presents a comparison of steam turbine main operating parameters when gland seals operation is neglected (as usual in the most of the literature) and when steam mass flow rates leaked through all gland seals are taken into consideration. Steam mass flow rate leakage through all gland seals reduces produced power of the whole turbine and both of its cylinders. Operation of gland seal mounted at the inlet in the first cylinder of any steam turbine (cylinder which operates with the steam of the highest pressure) has the most notable influence on the reduction of the whole turbine produced power. Gland seal mounted at the outlet of the last turbine cylinder (cylinder which operates with the steam of the lowest pressure) did not have any influence on the reduction of steam turbine produced power. In any detail analysis of a steam turbine (especially the complex turbine with multiple cylinders), gland seals operation should be considered due to their notable influence on the turbine performance

Artificial neural network for predicting values of residuary resistance per unit weight of displacement

This paper proposes the usage of an Artificial neural network (ANN) to predict the values of the residuary resistance per unit weight of displacement from the variables describing ship’s dimensions. For this purpose, a Multilayer perceptron (MLP) regressor ANN is used, with the grid search technique being applied to determine the appropriate properties of the model. After the model training, its quality is determined using R2 value and a Bland-Altman (BA) graph which shows a majority of values predicted falling within the 95% confidence interval. The best model has four hidden layers with ten, twenty, twenty and ten nodes respectively, uses a relu activation function with a constant learning rate of 0.01 and the regularization parameter L2 value of 0.001. The achieved model shows a high regression quality, lacking precision in the higher value range due to the lack of data

The Analysis of Hungarian Indebtedness after 1989

Hungary has struggled with budget problems throughout its post-socialist history. With knowledge of economic theory it is possible to analyze the evolution of Hungary's debt after 1989 and thus deduce its weaknesses. Populism and fiscal irresponsibility have characterized majority of Hungarian governments to some extent. Hence, the key to understanding the debt of Hungary may be found on the political level of budgetary policy. With regard to the economic situation, Hungary was forced to implement significant cost-saving measures in recent years. These measures are evaluated at the end of the work. They can be crucial not only in terms of the budgetary situation but also with respect to the perspective on the future economic development and competitiveness of the entire economy

The Evolution of Hungarian Debt

In the world of rising public sectors, investigation of government deficits and increasing government debts is starting to be important both in theoretical economics and political reality. Hungary is one of the EU member countries with the major public debt problems. As primal cause of Hungarian debts, the trauma of revolutionary year 1956 could be accepted. Government officials began "to bribe" Hungarian citizens by many social security benefits and government expenditures which were so large that government revenues couldn't have covered them. This course led to culminating government debt in relation to ignorance of economic reality. There weren't considerable changes in this evolution even after 1989. Government debt is still the biggest macroeconomic weakness of Hungary, which financial crisis has revealed

The Evolution of Hungarian Debt

Ve světě rostoucích veřejných sektorů začíná nabývat na významu jak v teoretické ekonomii, tak politické realitě zkoumání státních deficitů a rostoucího dluhu. Jednou ze zemí EU, která má ve spojení se státním dluhem největší potíže, je Maďarsko. Jako prvotní historickou příčinu vzniku maďarského zadlužení lze vnímat trauma z revolučního roku 1956. Vládní činitelé začali "uplácet" své občany mnoha sociálními dávkami a veřejnými výdaji a to tak velkými, že je veřejné příjmy nemohly pokrýt. Ve spojení s ignorací ekonomické reality tento postup vedl ke kulminujícímu státnímu zadlužení. K výrazné změně v tomto vývoji nedošlo ani po roce 1989. Státní dluh tak i v současnosti zůstává největší makroekonomickou slabinou Maďarska, jak ukázala i finanční krize.In the world of rising public sectors, investigation of government deficits and increasing government debts is starting to be important both in theoretical economics and political reality. Hungary is one of the EU member countries with the major public debt problems. As primal cause of Hungarian debts, the trauma of revolutionary year 1956 could be accepted. Government officials began "to bribe" Hungarian citizens by many social security benefits and government expenditures which were so large that government revenues couldn't have covered them. This course led to culminating government debt in relation to ignorance of economic reality. There weren't considerable changes in this evolution even after 1989. Government debt is still the biggest macroeconomic weakness of Hungary, which financial crisis has revealed

Techniques of intracranial EEG processing in a model of temporal lobe epilepsy

To understand the role of various limbic structures in pathophysiology of temporal role epilepsy requires understanding of its functional organization. We have developed technique of recording of spontaneous and evoked acitvity in chronic model of temporal lobe epilepsy. In addition, we created a computer programme which allows sequential processing of large data sets and analysis and quantification of spontaneous epileptic activity and evoked potentials. This programme implements various techniques of seizure, HFO and interictal discharge detectio

Functional mapping and excitability testing of limbic structures in vivo

We have focused on analysis of functional connectivity and excitability testing of limbic structures in vivo. Results demonstrated that stimulation of ventral commisure activates preferentially dorsal hippocampus and medial entorhinal corte

Diagnostika stavu záznamové vrstvy optických paměťových médií DVD pomocí mikroskopu LEXT

Optická záznamová média lze pokládat v současnosti za nejrozšířenější přenosné medium pro ukládání dat, a to i přesto, že se již začínají na trhu objevovat nová média využívající technologii Blue Ray. Nejasnosti jsou ale v tom, po jaké době bude možné datový záznam uložený na tomto optickém médiu ještě přečíst. Příspěvek je věnován formám degradace tohoto media a možnostem diagnostiky stavu záznamové vrstvy DVD pomocí konfokálního laserového mikroskopu LEXT firmy Olympus

Energy and Exergy Analysis of Waste Heat Recovery Closed-Cycle Gas Turbine System while Operating with Different Medium

In this paper is performed energy and exergy analysis of waste heat recovery closed-cycle gas turbine system. Analyzed system can use waste heat from various main propulsors (gas turbines or internal combustion engines). Basically, the observed system operates by using CO2, what was the baseline for the analysis. It is investigated did the observed system, while retaining the same configuration, can operate with different operating mediums instead of CO2. Other observed operating mediums were Air and Helium. During the change in operating medium, pressures and temperatures in some system operating points cannot remain the same as in the process with CO2, but the intention was to perform only the necessary changes (to ensure proper operation of each system component). Obtained results show that the system, while retaining the same configuration, can operate by using different operating mediums. Energy analysis of the system shows that the whole configuration is composed to operate with CO2, because the whole system energy efficiency is much higher than in operation with Air or Helium. The energy efficiency of the whole system during operation with CO2 is 87.68%, with Air is 58.39% and operation with Helium gives energy efficiency of 49.25%. Exergy analysis of the observed system shows that the system has a good potential to operate with other mediums, because in any observed situation exergy efficiency of the whole system was higher than 50%. In this analysis the highest exergy efficiency of the whole system was obtained during operation with Air (57.76%). In the observed system, low-temperature regenerator and main turbo-compressor are detected as components which are highly influenced by the change of operating medium. Therefore, these two components should be a baseline for further improvements and system optimization