Management of By-Product Created by Lye-Sodium Brine Purification Method Using Carbonization

The article presents carbonization as a method of waste management from the brine sodium-lime method. It was compared with the previously obtained results for the lye-sodium one. Within it, the fltration and washing times were contrasted for treated and non-carbonised samples. For this aim potentiometric titration analysis was used to determine the precipitation's basic components and by-product brine. Scanning electron microscope with energy dispersive X-ray spectrum and diffractographic analysis were used for morphology analysis what allowed to determine the tested samples' composition. It was found that despite significant differences in the time of washing and filtration, the time of these processes is shortened after the suspension has been exposed to carbon dioxide. In both cases the composition allows the waste brine to be recycled to the purifcation processes and the mixture of calcium and magnesium compounds become alternative raw material. It turned out that in both methods it is possible to utilize the suspension formed

Energy Transition in Poland—Assessment of the Renewable Energy Sector

The topic of the article considers the functioning of the renewable energy (RE) sector in Poland. This is really important in the context of the energy transition of the national economy because it influences the creation of modern technologies and increases the competitiveness and innovation of the country. Poland is in a process of energy transition where the RE sector has been developing for two decades. The authors aimed to research the RE sector improvement possibilities in Poland, including the influence of this sector on chosen social and economic aspects. Because of this research’s aim a critical situation assessment of RE in Poland was conducted and a survey of a group of experts in this field was also involved. Legal, physical and mental determinants and their influence on RE sector were looked into. In the legal determinant context a necessity to simplify relevant legislation acts in Poland was found. Undoubtedly there is a need to improve several legal acts, including the Distance Act. In physical determinants it was found that solar, wind and biomass energy have the biggest chances for development. In the case of mental determinants the authors paid attention to the need of educating the public about using and obtaining energy. It is also important to make people aware how the RE sector influences the low emission economy positively. This will improve the creation of new jobs and reduce the emissions of harmful substances to the environment

15 Years of the Polish agricultural biogas plants: their history, current status, biogas potential and perspectives

Biogazownie rolnicze w Polsce

Energia odnawialna w województwie warmińsko-mazurskim, 158 s.

Energetyka odnawialna (OZE) jest szeroko rozwijana na świecie, w tym również w Polsce. W najbliższych latach przewiduje się dalszy rozwój OZE w Polsce. Stąd też zrodził się pomysł napisania niniejszej monografii. Pierwszym celem przeprowadzonych badań było wyznaczenie potencjału technicznego energii odnawialnej w Polsce. W przypadku biomasy założono, że w większym stopniu należy wykorzystać biomasę odpadową oraz zagospodarować grunty ugorowane i nieużytki. Obliczono również potencjał techniczny aeroenergetyki w Polsce z wykorzystaniem metody GIS na podstawie danych uzyskanych z IMGW. W przypadku helioenergetyki i pomp ciepła przyjęto, że panele fotowoltaiczne, kolektory słoneczne i pompy ciepła należy montować na istniejących budynkach użyteczności publicznej i obiektach nowo budowanych Drugim celem badań było przeprowadzenie ankiet socjometrycznych. W latach 2009–2018 przygotowano i wysłano ankiety do firm, właścicieli urządzeń OZE w Polsce, rolników, uczniów i nauczycieli. Trzecim celem badań było przeprowadzenie analizy SWOT i PEST energetyki odnawialnej w Polsce

The prognostic value of fixed time and self-paced walking tests in patients diagnosed with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a specific form of chronic fibrosing interstitial pneumonia that has an unknown etiology. The natural history of the disease is characterized by a progressive decline in pulmonary function and overall health and well-being. The median survival time is between 2–3 years; however, the disease course is variable and unpredictable.The twelve-minute walking test (12MWT) and six-minute walking test (6MWT) are two fixed time tests that are commonly used in clinical practice. Our short and clinically oriented narrative review attempted to summarize current evidence supporting the use of fixed time, self-paced walking tests in predicting the outcome of patients diagnosed with IPF. A number of studies have justified that the 6MWT is a simple, cost-effective, well documented, fixed time, and self-paced walking test which is a valid and reliable measure of disease status and can also be used as a prognostic tool in patients with IPF. However, there is a need for dedicated and validated reference equations for this population of patients. It is also necessary to fill the knowledge gap about the role of the 12MWT. We hypothesize that it would be useful in evaluating patients that are in the early stages of the disease

Six-phase doubly fed induction machine-based standalone DC voltage generator

The paper presents a multi-phase doubly fed induction machine operating as a DC voltage generator. The machine consists of a six-phase stator circuit and a three-phase rotor circuit. Two three-phase six-pulse diode rectifiers are connected to each three-phase machine section on the stator side and in parallel to the common DC circuit feeding the isolated load. The same DC bus is also common for the rotor side power electronics converter responsible for machine control. Two methods – direct torque control DTC and field oriented control FOC – were implemented for machine control and compared by means of simulation tests. Field oriented control was implemented in the laboratory test bench

Non-Cartesian Frame Transformation-Based Control of a Three-Phase Power Converter During Unbalanced Voltage Dip – Part II: Simulation And Experiment

The paper presents a control method for the three-phase power converter operating under unbalanced grid voltage conditions. The method uses a new transformation to the non-Cartesian frame, which makes the controlled current vector components balanced in this frame even if originally the three-phase current is referenced as unbalanced. Furthermore, Park’s transformation makes the controlled variables constant, which allows to apply proportional–integral terms as current controllers independent of the required control target. Several control targets known from literature have been analyzed with regard to the required new transformation parameters, and the transformation parameters for all targets have been found. Simulation results are shown to prove the theoretical analysis, and the experimental test results are presented as practical validation of the proposed use of the non-Cartesian frame in control

Non-Cartesian Frame Transformation-Based Control of a Three-Phase Power Converter During Unbalanced Voltage Dip – Part I: Transformation Principles

One of the currently investigated problems in power electronics-based electrical energy conversion is proper operation of electronic converters during grid voltage imbalance and harmonics. In classic control methods, it introduces oscillations of variables, resulting in the necessity to improve control systems with signals filtration and usually by application of resonant terms as part of current controllers. The paper presents a new approach to grid-connected inverter control based on transformation to a non-Cartesian frame, the parameters of which are correlated with grid voltage asymmetry. The proposed method results in resignation from resonant terms used as controllers and their replacement with proportional–integral terms for which anti-wind-up structures are significantly simpler than for oscillatory terms. The paper presents new transformation principles, features and some simulation results showing the waveforms of signals transformed to the new non-Cartesian frame