Classicality of the Bogoliubov transformations and the dynamical Casimir effect through the reduced state of the field

We use the reduced state of the field formalism [Entropy 21, 705 (2019)] to derive conditions under which a Bogoliubov transformation can be considered semi-classical. We apply this result to the dynamical Casimir effect in a moving medium [Phys. Rev. A 78, 042109 (2008)], discussing its classical and quantum features.Comment: This article belongs to the special issue of Acta Physica Polonica A printed in honor of Professor Iwo Bialynicki-Birula on the occasion of his 90th birthday (Ed. Tomasz Sowinski, DOI:10.12693/APhysPolA.143.S0

METODY BALANSOWANIA OGNIW W TRAKCYJNYCH AKUMULATORACH LITOWO-JONOWYCH

Batteries in lithium-ion technology have many advantages over traditional lead-acid batteries. High specific energy and power, quick-charging, wide operating temperature range are their main features particularly appreciated in traction applications. However, they require safety and control systems for their work. One of the major functions of such a system is a function of balancing, equalizing the charge level of individual cells. This paper presents balancing metod of li-ion batteries.Akumulatory w technologii litowo-jonowej posiadają wiele zalet w porównaniu z tradycyjnymi akumulatorami kwasowo-ołowiowymi. Wysoka energia i moc właściwa, możliwość szybkiego ładowania, szerszy zakres temperatur pracy to cechy szczególnie doceniane w zastosowaniach trakcyjnych. Jednak wymagają one współpracy układów zabezpieczających i sterujących ich pracą. Jedną z ważniejszych funkcji takiego układu jest funkcja balansowania, czyli wyrównywania poziomu naładowania poszczególnych ogniw. W niniejszym artykule wyjaśniono cel balansowania, opisano metody realizacji tego procesu z uwzględnieniem zalet i wad każdej z nich

Impact of PWM Control Frequency onto Efficiency of a 1 kW Permanent Magnet Synchronous Motor

The paper explains how to select the best PWM control frequency for specific Permanent Magnet Synchronous Motors (PMSM) to achieve its maximum efficiency. Examinations were carried out for a PMSM unit with the power of 1 kW, rated speed of 1000 rpm and rated torque of 6 Nm. The PWM frequency ranged from 4 kHz to 20 kHz with the increment of 1 kHz. Measurements were taken for each of the foregoing frequencies, for the load torques of 2 Nm, 4 Nm and 6 Nm and for the rotation speeds of 300 rpm, 500 rpm, 750 rpm, 1000 rpm and 1200 rpm to find out efficiency of the PMSM motor. The achieved results make it possible to properly adjust the PWM control frequency for each PMSM motor to operate the motor in the most efficient way and, in consequence, save energy consumed by that motor

METODY WYZNACZANIA STANU NAŁADOWANIA AKUMULATORÓW STOSOWANE W POJAZDACH ELEKTRYCZNYCH, URZĄDZENIACH PRZENOŚNYCH I W LABORATORIUM

State-of-charge of battery is a very important parameter for any electrical vehicle or mobile device user. It allows estimating the time range and in the case of electric vehicles available distance range. The paper presents the main methods for determining the state-of-charge of batteries used in portable devices, electric vehicles, and at laboratories. The principle of each method, described here, their advantages and disadvantages and applicability to specific devices has been explained.Stan naładowania akumulatora jest bardzo istotnym parametrem dla użytkownika pojazdu elektrycznego lub urządzenia przenośnego. Pozwala on oszacować pozostały czas pracy, a w przypadku pojazdów elektrycznych dostępny zasięg. Artykuł przedstawia najważniejsze metody służące do wyznaczania stanu naładowania akumulatorów, stosowane w urządzeniach przenośnych, pojazdach elektrycznych, a także w badaniach laboratoryjnych. Wyjaśniono istotę działania każdej z metod, opisano ich wady i zalety oraz możliwości zastosowania do konkretnych urządzeń

Application range of crosstalk-affected spatial demultiplexing for resolving separations between unbalanced sources

Superresolution is one of the key issues at the crossroads of contemporary quantum optics and metrology. Recently, it was shown that for an idealized case of two balanced sources, spatial mode demultiplexing (SPADE) achieves resolution better than direct imaging even in the presence of measurement crosstalk [Phys. Rev. Lett. 125, 100501 (2020)]. In this work, we consider arbitrarily unbalanced sources and provide a systematic analysis of the impact of crosstalk on the resolution obtained from SPADE. As we dissect, in this generalized scenario, SPADE's effectiveness depends non-trivially on the strength of crosstalk, relative brightness and the separation between the sources. In particular, for any source imbalance, SPADE performs worse than ideal direct imaging in the asymptotic limit of vanishing source separations. Nonetheless, for realistic values of crosstalk strength, SPADE is still the superior method for several orders of magnitude of source separations.Comment: 10 pages, 6 figure

Changes in disease burden in Poland between 1990-2017 in comparison with other Central European countries : a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND:Systematic collection of mortality/morbidity data over time is crucial for monitoring trends in population health, developing health policies, assessing the impact of health programs. In Poland, a comprehensive analysis describing trends in disease burden for major conditions has never been published. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides data on the burden of over 300 diseases in 195 countries since 1990. We used the GBD database to undertake an assessment of disease burden in Poland, evaluate changes in population health between 1990-2017, and compare Poland with other Central European (CE) countries. METHODS:The results of GBD 2017 for 1990 and 2017 for Poland and CE were used to assess rates and trends in years of life lost (YLLs), years lived with disability (YLDs), disability-adjusted life years (DALYs). Data came from cause-of-death registration systems, population health surveys, disease registries, hospitalization databases, and the scientific literature. Analytical approaches have been used to adjust for missing data, errors in cause-of-death certification, and differences in data collection methodology. Main estimation strategies were ensemble modelling for mortality and Bayesian meta-regression for disability. RESULTS:Between 1990-2017, age-standardized YLL rates for all causes declined in Poland by 46.0% (95% UI: 43.7-48.2), YLD rates declined by 4.0% (4.2-4.9), DALY rates by 31.7% (29.2-34.4). For both YLLs and YLDs, greater relative declines were observed for females. There was a large decrease in communicable, maternal, neonatal, and nutritional disease DALYs (48.2%; 46.3-50.4). DALYs due to non-communicable diseases (NCDs) decreased slightly (2.0%; 0.1-4.6). In 2017, Poland performed better than CE as a whole (ranked fourth for YLLs, sixth for YLDs, and fifth for DALYs) and achieved greater reductions in YLLs and DALYs than most CE countries. In 2017 and 1990, the leading cause of YLLs and DALYs in Poland and CE was ischaemic heart disease (IHD), and the leading cause of YLDs was low back pain. In 2017, the top 20 causes of YLLs and YLDs in Poland and CE were the same, although in different order. In Poland, age-standardized DALYs from neonatal causes, other cardiovascular and circulatory diseases, and road injuries declined substantially between 1990-2017, while alcohol use disorders and chronic liver diseases increased. The highest observed-to-expected ratios were seen for alcohol use disorders for YLLs, neonatal sepsis for YLDs, and falls for DALYs (3.21, 2.65, and 2.03, respectively). CONCLUSIONS:There was relatively little geographical variation in premature death and disability in CE in 2017, although some between-country differences existed. Health in Poland has been improving since 1990; in 2017 Poland outperformed CE as a whole for YLLs, YLDs, and DALYs. While the health gap between Poland and Western Europe has diminished, it remains substantial. The shift to NCDs and chronic disability, together with marked between-gender health inequalities, poses a challenge for the Polish health-care system. IHD is still the leading cause of disease burden in Poland, but DALYs from IHD are declining. To further reduce disease burden, an integrated response focused on NCDs and population groups with disproportionally high burden is needed

The Athena X-ray Integral Field Unit: a consolidated design for the system requirement review of the preliminary definition phase

The Athena X-ray Integral Unit (X-IFU) is the high resolution X-ray spectrometer, studied since 2015 for flying in the mid-30s on the Athena space X-ray Observatory, a versatile observatory designed to address the Hot and Energetic Universe science theme, selected in November 2013 by the Survey Science Committee. Based on a large format array of Transition Edge Sensors (TES), it aims to provide spatially resolved X-ray spectroscopy, with a spectral resolution of 2.5 eV (up to 7 keV) over an hexagonal field of view of 5 arc minutes (equivalent diameter). The X-IFU entered its System Requirement Review (SRR) in June 2022, at about the same time when ESA called for an overall X-IFU redesign (including the X-IFU cryostat and the cooling chain), due to an unanticipated cost overrun of Athena. In this paper, after illustrating the breakthrough capabilities of the X-IFU, we describe the instrument as presented at its SRR, browsing through all the subsystems and associated requirements. We then show the instrument budgets, with a particular emphasis on the anticipated budgets of some of its key performance parameters. Finally we briefly discuss on the ongoing key technology demonstration activities, the calibration and the activities foreseen in the X-IFU Instrument Science Center, and touch on communication and outreach activities, the consortium organisation, and finally on the life cycle assessment of X-IFU aiming at minimising the environmental footprint, associated with the development of the instrument. Thanks to the studies conducted so far on X-IFU, it is expected that along the design-to-cost exercise requested by ESA, the X-IFU will maintain flagship capabilities in spatially resolved high resolution X-ray spectroscopy, enabling most of the original X-IFU related scientific objectives of the Athena mission to be retained. (abridged).Comment: 48 pages, 29 figures, Accepted for publication in Experimental Astronomy with minor editin