85 research outputs found
O symetrii zjawisk fizycznych, symetrii pola elektrycznego i pola magnetycznego
In the work, the classical concept of symmetry limited to geometric objects (figures, solids), which originated from ancient Greece, has been extended to allow for symmetry studies in other types of objects. By introducing concepts of limit point groups and kinematic elements, which characterize a studied object, it was determined what types of symmetries an electric field and a magnetic field exhibit. It was established that, in order for a phenomenon to occur, a characteristic symmetry of a medium must be consistent with the characteristic symmetry of the phenomenon occurring in it. It was also determined that elements of symmetry of causes must be reflected in the symmetry of the induced effects.W pracy klasyczne pojęcie symetrii ograniczone do obiektów geometrycznych (figur, brył), znajdujące swoje źródło w antycznej Grecji, zostało rozszerzone tak, by możliwe było badanie symetrii innych rodzajów obiektów. Poprzez wprowadzenie pojęcia granicznych grup punktowych i elementów kinematycznych charakteryzujących obiekt, którego symetria jest badana, określono, jakiego typu symetrie wykazują pole elektryczne i pole magnetyczne. Ustalono, że aby możliwe było zachodzenie jakiegoś zjawiska, to charakterystyczna symetria ośrodka musi być zgodna z charakterystyczną symetrią występującego w nim zjawiska. Stwierdzono, także, że elementy symetrii przyczyn muszą znaleźć odzwierciedlenie w symetrii wywołanych skutków
The mission of scientific, legal journals in times of constitutional crisis and constitutional anomy
Odwołując się do stuletniej historii „Ruchu Prawniczego, Ekonomicznego i Socjologicznego” oraz ponadsiedemdziesięcioletniej tradycji „Państwa i Prawa”, dwóch najbardziej prestiżowych czasopism prawniczych w Polsce, autorzy rozważają pojęcie misji czasopisma naukowego i jej znaczenie w demokratycznym społeczeństwie. Rozważania te osadzone zostały w szczególnym kontekście: rewolucji konstytucyjnych, w trakcie których utrwalone interpretacje konstytucyjne są kwestionowane, a przepisy konstytucyjne – naruszane. Tłem rozważań autorów są zmiany polskiego prawa i praktyki z lat 2015–2020 o znaczeniu konstytucyjnym. Ten okolicznościowy artykuł szkicuje odpowiedź na pytanie, jak czasopisma prawnicze powinny reagować na sytuację „wymazywania” konstytucji (by użyć obrazowej metafory Mirosława Wyrzykowskiego). Aby odpowiedzieć na to pytanie, autorzy odwołują się kolejno do koncepcji: rewolucji konstytucyjnej, kryzysu konstytucyjnego, oraz adaptują pojęcie anomii konstytucyjnej. Artykuł ma w istotnej mierze charakter deskryptywny oraz interpretacyjny, choć jego części mogą służyć dalszym rozważaniom normatywnym.Referring to the honourable one-hundred-year history of Ruch Prawniczy, Ekonomiczny i Socjologiczny, and the more than seventy-year tradition of Państwo i Prawo, the two most prestigious legal journals in Poland, the authors discuss the mission of legal journals in a democratic society. They focus on the times of constitutional revolutions and transformations, where the well-established interpretations of constitutional provisions became questioned or even violated. The 2015−2020 constitutional developments in Poland serve as an illustrative background and point of reference for the authors in answering the following question: how and what should legal journals publish when the constitution is being ‘vanished’ (to use the compelling metaphor of Mirosław Wyrzykowski). This predominantly descriptive and interpretative article consists of the following four parts: the mission of journals, constitutional revolution, constitutional crisis, and constitutional anomy
Measurement of Exhaust Emissions under Actual Operating Conditions with the Use of PEMS: Review of Selected Vehicles
This paper is a synthetic approach to real driving (RDE) from selected vehicles: light-duty vehicle (LDV), heavy-duty vehicle (HDV). The tests were performed with the portable emission measurement system (PEMS) equipment under actual traffic conditions. The paper discusses problems of measurement methodology and emission of CO, HC, NOx, and PM. The performed investigation confirms that the main problem is the emission of NOx and PM, which usually is higher than the emission level. The obtained results show that the RDE method is very complex, but is the only way to provide invaluable information on the actual on-road exhaust emissions, not obtainable under laboratory conditions. In recent years, methods of exhaust emission testing under actual operating conditions have been developing rapidly. New technologies for extra low engine emissions pose a new question: does emission testing in a standard laboratory reflects real life emissions of a vehicle in use? In order to answer this question, it is necessary to measure the vehicle in-use emissions. Today, we know that the engine operating conditions (engine load and speed) in laboratory tests are not compliant with the conditions of actual operation. That is why the results of such tests are so desirable
Adventitial lymphatics of internal carotid artery in healthy and atherosclerotic vessels.
OBJECTIVESPresence of lymphatics in adventitia of major arteries remains controversial. Presence of lymphatics in adventitia of internal carotid artery was not documented and its relation to atherosclerosis was not studied. The aim of our study was to evaluate presence of lymphatic vessels in adventitia of internal carotid artery in healthy and atherosclerotic arteries.METHODSFragments of arterial wall of internal carotid artery were obtained during the surgical eversion endarterectomy in 15 patients with internal carotid artery stenosis and 2 healthy organ donors. 21 arteries were studied. Patients age ranged from 56 to 77 years. Fragments of arterial wall were embeded in paraffin. Lymphatics of arterial adventitia were visualized with immunohistochemistry using LYVE-1 and anty-podoplanin antibodies.RESULTSThe lymphatic vessels were visualized in adventitia of 20 carotid arteries. The serial sections have revealed that both LYVE-1 and podoplanin have identical specificity for lymphatic endothelium Number of lymphatics in adventitia significantly correlated with thickness of intima (
Neurofeedback training for peak performance
Aim. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the
neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions.
The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete
who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in
spontaneous EEG and event related potentials (ERPs).
Case study. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He
wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and
after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by
error measurement were observed in the patient.
Conclusion. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of
ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex.
Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance
brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance
Testing the Dynamics of Flight for the Products of Explosion for a Warhead with a Weight of 250 kg
This study presents the results of the testing of the explosion process of a warhead with a weight of 250 kg, filled with 87 kg of TNT with 20% of aluminium dust, in two configurations: with horizontal and vertical alignment of the warheads longitudinal axis, and with the centre of length of the warhead body located at a height of approx. 1 m above the ground. Four warheads were detonated in each configuration. The horizontal configuration allowed the collection of some amount of the fragments from the ground, with sizes and spatial distribution of the fragments corresponding to the location on the body from which they came, with the largest fragments from the central part of the shell measuring approximately 9 30 280 mm. For the vertical configuration, the warheads nose was pointed downwards, with an up-down excitation. In both configurations, the explosion process was recorded from a distance of 300 m using a PHANTOM fast camera with a time resolution (frame interval) of 55 s to 133 s: for the horizontal configuration along the bodys longitudinal axis, for the vertical configuration perpendicular to this axis. In the vertical configuration, the bodys expansion process was recorded using short-circuit sensors spaced every 5 mm along the flight radius. The sensors sent short-circuit signals to the time meter, whereas the first sensor was installed at a distance of approx. 1 mm from the body surface and was used to initiate the processes of time counting and recording the overpressure diagrams over time at the front of the explosion/shock (FU) wave. The recorded expansion velocity was approx. 1300 m/s, with the shell radius increasing by 20 mm. Overpressure at the front of the FU was measured by PCB pencil-tip piezoelectric sensors (CzP). Every sensor had two active surfaces arranged in tandem at a distance of 100 mm, which made it possible to determine the local FU velocity. Signals from CzP were recorded every 200 ns using a DEWETRON recorder with software allowing their initial and further processing. Three sensors were spaced 8 m from each other, whereas the first was located 8 m to 10 m from the warheads longitudinal axis. Under a row of the sensors a thick-wall steel pipe was placed to protect the sensors from destruction by the fragments. The determined local FU velocities varied from approx. (590 m/s to 740 m/s) at a distance of approx. 8 m from the epicentre up to approx. 370 m/s at a distance of approx. 26 m from the epicentre; the overpressure measured values varied from approx. (230 kPa to 550 kPa) at a distance of approx. 8 m to approx. 22 kPa at a distance of approx. 26 m from the epicentre; satisfying conformance of the velocity and pressure values under the flat FU model was found. The FU trajectory was also taken from the video recording the velocities measured varied from approx. 2,650 m/s at a distance of 0.3 m to approx. 670 m/s at a distance of 6 m from the epicentre, which corresponds to the CzP data. The fragments flying next to the CzP, generally with the highest mass to effective transverse surface ratio, left traces of their conical FU on the CzP overpressure records, which allowed the determination of average velocities for some of them across the access path to the CzP, whereas these velocities ranged from approx. 1700 m/s at a distance of approx. 8 m and (1500 m/s to 1600 m/s) at a distance of 16 m to approx. 1300 to 1400 m/s at a distance of 26 m from the epicentre. Average access velocities of the selected fragments to the field marks were determined on the basis of the video recording ranged from approx. 1800 m/s at a distance of 5 m to approx. 1500 m/s at a distance of 20 m from the explosion epicentre
The Melting Process and its Impact on the Properties of High-Chromium Cast Iron and the Economic Calculation
The subject of this study is to show that the parameters of the melting process of high chromium cast iron affect the cost of casting and the properties of the cast iron. The analysis of the quality of the casting and its price was conducted in terms of the metal charge of high chromium cast iron. As is well known, in order to obtain the correct structure of the casting, and thus good strength properties, it is necessary to use clean batch components free of undesirable impurities. Unfortunately, the quality of the metal charge is proportional to its price. Thus, the use of expensive batch components offers the possibility of obtaining healthy and meeting the strength properties of castings. However, there is a flaw in this approach. And it is from the point of view of economics that production plants are forced to look for savings. Expensive feedstock materials are replaced by cheaper counterparts giving the possibility of obtaining castings with similar properties often, however, at the cost of increased inferior quality. It seems that a way out of this situation is to introduce a modification procedure into the alloyed iron manufacturing technology. The selected modifiers should affect the fragmentation of the structure of the primary austenite. At this point, it can be hypothesized that this will result in the elimination of hot cracking in high chromium cast iron. The industrial research carried out at the "Swidnica" Foundry Ltd. made it possible to show by means of the Althoff-Radtke method that by using the modification of the liquid metal of the so-called "inferior and cheaper" composition of the metal charge, a reduction in the occurrence of hot cracks and shrinkage cavities can be achieved. In addition, iron-niobium modification not only reduced the formation of casting defects in castings, but also slightly improved the impact strength of high-chromium cast iron. The work was written as part of an implementation PhD
- …