COMPARATIVE ANALYSIS OF ENERGY ACCUMULATION SYSTEMS AND DETERMINATION OF OPTIMAL APPLICATION AREAS FOR MODERN SUPER FLYWHEELS

The paper presents a review and comparative analysis of late years native and foreign literature on various energy storage devices: state of the art designs, application experience in various technical fields. Comparative characteristics of energy storage devices are formulated: efficiency, quality and stability. Typical characteristics are shown for such devices as electrochemical batteries, super capacitors, pumped hydroelectric storage, power systems based on compressed air and superconducting magnetic energy storage systems. The advantages and prospects of high-speed super flywheels as means of energy accumulation in the form of rotational kinetic energy are shown. High output power of a super flywheels energy storage system gives the possibility to use it as a buffer source of peak power. It is shown that super flywheels have great life cycle (over 20 years) and are environmental. A distinctive feature of these energy storage devices is their good scalability. It is demonstrated that super flywheels are especially effective in hybrid power systems that operate in a charge/discharge mode, and are used particularly in electric vehicles. The most important factors for space applications of the super flywheels are their modularity, high efficiency, no mechanical friction and long operating time without maintenance. Quick response to network disturbances and high power output can be used to maintain the desired power quality and overall network stability along with fulfilling energy accumulation needs

Medical Radioisotopes Produced with Cyclotron Beams in Warsaw

The various production routes of the prospective medical radioisotopes 43Sc, 44gSc, 44mSc, 47Sc, 44Ti/44gSc, 99mTc, 72Se/72As and 211At were investigated by a team from the Heavy Ion Laboratory, University of Warsaw (HIL-UW), the University of Silesia (US) and the National Centre for Nuclear Research (NCNR). Three cyclotrons were employed: the K=160 heavy-ion cyclotron with an internal 32 MeV alpha particle beam and the p/d PETtrace medical cyclotron at HIL and the C30 proton cyclotron at NCNR in Świerk, near Warsaw. The Thick Target Yields, activity at the End of Bombardment (EOB) and the impurities produced in addition to the main isotope are reported. The possible medical applications of these radioisotopes are briefly discussed

His bundle pacing, learning curve, procedure characteristics, safety, and feasibility: Insights from a large international observational study

Background His‐bundle pacing (HBP) provides physiological ventricular activation. Observational studies have demonstrated the techniques feasibility however, data has come from a limited number of centres. Objectives We set out to explore contemporary global practise in HBP focusing on learning curve, procedural characteristics and outcomes. Methods This is a retrospective, multi‐centre observational study of patients undergoing attempted HBP at seven centres. Pacing indication, fluoroscopy time, HBP thresholds and lead re‐intervention and deactivation rates were recorded. Where centres had systematically recorded implant success rates from the outset, these were collated. Results 529 patients underwent attempted HBP during the study period (2014‐19) with mean follow‐up of 217±303 days. Most implants were for bradycardia indications. In the three centres with systematic collation of all attempts, overall implant success rate was 81% which improved to 87% after completion of 40 cases. All seven centres reported data on successful implants. Mean fluoroscopy time was 11.7±12.0 minutes, His‐bundle capture threshold at implant was 1.4±0.9V at 0.8±0.3 ms and was 1.3±1.2V at 0.9±0.2ms at last device check. HBP lead re‐intervention or deactivation (for lead displacement or rise in threshold) occurred in 7.5% of successful implants. There was evidence of a learning curve: fluoroscopy time and HBP capture threshold reduced with greater experience, plateauing after ~30‐50 cases. Conclusion We found that it is feasible to establish a successful HBP program, using the currently available implantation tools. For physicians who are experienced at pacemaker implantation the steepest part of the learning curve appears to be over the first 30‐50 cases

The agt gene m235t polymorphism and response of power-related variables to aerobic training

© Journal of Sports Science and Medicine.The C allele of the M235T (rs699) polymorphism of the AGT gene correlates with higher levels of angiotensin II and has been associated with power and strength sport performance. The aim of the study was to investigate whether or not selected power-related variables and their response to a 12-week program of aerobic dance training are modulated by the AGT M235T genotype in healthy participants. Two hundred and one Polish Caucasian women aged 21 ± 1 years met the inclusion criteria and were included in the study. All women completed a 12-week program of low and high impact aerobics. Wingate peak power and total work capacity, 5 m, 10 m, and 30 m running times and jump height and jump power were determined before and after the training programme. All power-related variables improved significantly in response to aerobic dance training. We found a significant association between the M235T polymorphism and jump-based variables (squat jump (SJ) height, p = 0.005; SJ power, p = 0.015; countermovement jump height, p = 0.025; average of 10 countermovement jumps with arm swing (ACMJ) height, p = 0.001; ACMJ power, p = 0.035). Specifically, greater improvements were observed in the C allele carriers in comparison with TT homozygotes. In conclusion, aerobic dance, one of the most commonly practiced adult fitness activities in the world, provides sufficient training stimuli for augmenting the explosive strength necessary to increase vertical jump performance. The AGT gene M235T polymorphism seems to be not only a candidate gene variant for power/strength related pheno-types, but also a genetic marker for predicting response to training

Influence of Shear-Thinning Rheology on the Mixing Dynamics in Taylor-Couette Flow

Non‐Newtonian rheology can have a significant effect on mixing efficiency, which remains poorly understood. The effect of shear‐thinning rheology in a Taylor‐Couette reactor is studied using a combination of particle image velocimetry and flow visualization. Shear‐thinning is found to alter the critical Reynolds numbers for the formation of Taylor vortices and the higher‐order wavy instability, and is associated with an increase in the axial wavelength. Strong shear‐thinning and weak viscoelasticity can also lead to sudden transitions in wavelength as the Reynolds number is varied. Finally, it is shown that shear‐thinning causes an increase in the mixing time within vortices, due to a reduction in their circulation, but enhances the axial dispersion of fluid in the reactor

SOD2 gene polymorphism and muscle damage markers in elite athletes

Exercise-induced oxidative stress is a state that primarily occurs in athletes involved in high-intensity sports when pro-oxidants overwhelm the antioxidant defense system to oxidize proteins, lipids, and nucleic acids. During exercise, oxidative stress is linked to muscle metabolism and muscle damage, because exercise increases free radical production. The T allele of the Ala16Val (rs4880 C/T) polymorphism in the mitochondrial superoxide dismutase 2 (SOD2) gene has been reported to reduce SOD2 efficiency against oxidative stress. In the present study we tested the hypothesis that the SOD2 TT genotype would be underrepresented in elite athletes involved in high-intensity sports and associated with increased values of muscle and liver damage biomarkers. The study involved 2664 Caucasian (2262 Russian and 402 Polish) athletes. SOD2 genotype and allele frequencies were compared to 917 controls. Muscle and liver damage markers [creatine kinase (CK), creatinine, alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP)] were examined in serum from 1444 Russian athletes. The frequency of the SOD2 TT genotype (18.6%) was significantly lower in power/strength athletes (n = 524) compared to controls (25.0%, p = 0.0076) or athletes involved in low-intensity sports (n = 180; 33.9%, p < 0.0001). Furthermore, the SOD2 T allele was significantly associated with increased activity of CK (females: p = 0.0144) and creatinine level (females: p = 0.0276; males: p = 0.0135) in athletes. Our data show that the SOD2 TT genotype might be unfavorable for high-intensity athletic events

Design of the drive system controller using constrained multiobjective optimization

The article presents the results of multi-criteria optimization of the PI controller in positional linear drive with friction. In order to increase the effectiveness of known algorithm PAES [6] Authors proposed two modifications. The first one allows the exchange of archive solutions whose offspring solutions are ineffective. The second one allows elimination of solution violating limits. Optimization was based on two conflicting criteria – ITAE and ISU, and two subsidiary criteria – the maximum allowable set time and allowable overshoot. A significant increase in the efficiency of the algorithm PAES in determining effective solutions that meet the imposed limitations was achieved. The effectiveness of this method was confirmed by simulation

Symulacja wykorzystania akumulatora ciepła w elektrociepłowni

The sustainable management of energy production and consumption is one of the main challenges of the 21st century. This results from the threats to the natural environment, including the negative impact of the energy sector on the climate, the limited resources of fossil fuels, as well as the unstability of renewable energy sources – despite the development of technologies for obtaining energy from the: sun, wind, water, etc. In this situation, the efficiency of energy management, both on the micro (dispersed energy) and macro (power system) scale, may be improved by innovative technological solutions enabling energy storage. Their effective implementation enables energy storage during periods of overproduction and its use in the case of energy shortages. These challenges cannot be overestimated. Modern science needs to solve various technological issues in the field of storage, organizational problems of enterprises producing electricity and heat, or issues related to the functioning of energy markets. The article presents the specificity of the operation of a combined heat and power plant with a heat accumulator in the electricity market while taking the parameters affected by uncertainty into account. It was pointed out that the analysis of the risk associated with energy prices and weather conditions is an important element of the decision-making process and management of a heat and power plant equipped with a cold water heat accumulator. The complexity of the issues and the number of variables to be analyzed at a given time are the reason for the use of advanced forecasting methods. The stochastic modeling methods are considered as interesting tools that allow forecasting the operation of an installation with a heat accumulator while taking the influence of numerous variables into account. The analysis has shown that the combined use of Monte Carlo simulations and forecasting using the geometric Brownian motion enables the quantification of the risk of the CHP plant’s operation and the impact of using the energy store on solving uncertainties. The applied methodology can be used at the design stage of systems with energy storage and enables carrying out the risk analysis in the already existing systems; this will allow their efficiency to be improved. The introduction of additional parameters of the planned investments to the analysis will allow the maximum use of energy storage systems in both industrial and dispersed power generation.Zrównoważone zarządzanie produkcją i zużyciem energii stanowi jedno z naczelnych wyzwań XXI wieku. Wiąże się ono z zagrożeniami stanu środowiska przyrodniczego m.in. wskutek negatywnego wpływu energetyki na klimat, ograniczoności zasobów paliw kopalnych, a także niestabilności produkcji energii z wykorzystaniem źródeł odnawialnych – pomimo rozwijających się technologii pozyskania energii ze słońca, wiatru, wody, itp. W takiej sytuacji jednym ze sposobów poprawy efektywności gospodarki energetycznej – zarówno w skali mikro (energetyka rozproszona), jak i makro (system elektroenergetyczny), mogą być innowacyjne rozwiązania technologiczne umożliwiające magazynowanie energii. Ich skuteczna implementacja pozwoli na jej gromadzenie w okresach nadprodukcji i wykorzystanie w sytuacjach niedoboru. Wyzwania te są nie do przecenienia – przed współczesną nauką staje konieczność rozwiązywania różnego rodzaju zagadnień technologicznych w zakresie magazynowania, problemów organizacyjnych przedsiębiorstw wytwarzających energię elektryczną i ciepło, czy kwestii dotyczących funkcjonowania rynków energii. W artykule przedstawiono specyfikę funkcjonowania elektrociepłowni z magazynem ciepła na rynku energii elektrycznej w odniesieniu do związanych z tym parametrów obarczonych niepewnością. Zwrócono uwagę, że istotnym elementem procesu decyzyjnego i sterowania elektrociepłownią wyposażoną w niskotemperaturowy wodny akumulator ciepła – jako systemem – jest analiza ryzyka związanego z cenami energii oraz warunkami atmosferycznymi. Złożoność zagadnień, liczba zmiennych, jakie należy przeanalizować w danym czasie skłania do zastosowania zaawansowanych metod prognozowania. Uznano, że interesującymi narzędziami, które pozwalają na prognozowanie pracy instalacji z magazynem energii z uwzględnieniem wpływu wielu zmiennych mogą być stochastyczne metody modelowania. W wyniku zrealizowanych badań pokazano, że łączne wykorzystanie symulacji Monte Carlo i prognozowania z wykorzystaniem geometrycznego ruchu Browna umożliwia kwantyfikację ryzyka działalności elektrociepłowni i wpływ zastosowania magazynu energii na rozwiązywanie niepewności. Zastosowana metodyka może zostać wykorzystana zarówno na etapie projektowania systemów z magazynami energii, jak też umożliwić bieżącą analizę ryzyka w systemach już funkcjonujących; pozwoli to na poprawę efektywności ich funkcjonowania. Wprowadzenie do analizy dodatkowych parametrów planowanych inwestycji otworzy perspektywy maksymalneego wykorzystania wielkości magazynów energii zarówno w energetyce zawodowej, jak i rozproszonej

Innovative methods of heat storage

Kończące się zasoby paliw kopalnych, a także niestabilność produkcji energii ze źródeł odnawialnych powodują, że zrównoważone zarządzanie produkcją i zużyciem energii stanowi jedno z naczelnych wyzwań XXI wieku. Wiąże się ono również z zagrożeniami stanu środowiska przyrodniczego m. in. wskutek negatywnego wpływu energetyki na klimat. W takiej sytuacji jednym ze sposobów poprawy efektywności gospodarki energetycznej – zarówno w skali mikro (energetyka rozproszona), jak i makro (system elektroenergetyczny), mogą być innowacyjne rozwiązania technologiczne umożliwiające magazynowanie energii. Ich skuteczna implementacja pozwoli na jej gromadzenie w okresach nadprodukcji i wykorzystanie w sytuacjach niedoboru. Wyzwania te są nie do przecenienia – przed współczesną nauką staje konieczność rozwiązywania różnego rodzaju problemów związanych z magazynowaniem między innymi z zastosowaną technologią czy sterowaniem/zarządzaniem magazynami energii. Technologie magazynowania ciepła, nad którymi są prowadzone prace badawcze dotyczące zarówno magazynów opartych na medium takim jak woda, jak i magazynów wykorzystujących przemiany termochemiczne czy też materiały zmiennofazowe. Dają one szerokie możliwości zastosowania i poprawy efektywności systemów energetycznych zarówno w skali makro, jak i mikro. Oczywiście właściwości technologiczne oraz parametry ekonomiczne mają wpływ na zastosowanie wybranej technologii. W artykule przedstawiono porównanie magazynów czy sposobów magazynowania ciepła oparte na różnych materiałach z określeniem ich parametrów pracy czy kosztów eksploatacji.Finite fossil fuel resources, as well as the instability of renewable energy production, make the sustainable management of energy production and consumption some of the key challenges of the 21st century. It also involves threats to the state of the natural environment, among others due to the negative impact of energy on the climate. In such a situation, one of the methods of improving the efficiency of energy management – both on the micro (dispersed energy) and macro (power system) scale, may be innovative technological solutions that enable energy storage. Their effective implementation will allow it to be collected during periods of overproduction and to be used in situations of scarcity. These challenges cannot be overestimated - modern science has a challenge to solve various types of problems related to storage, including the technology used or the control/ /management of energy storage. Heat storage technologies, on which research works are carried out regarding both storage based on a medium such as water, as well as storage using thermochemical transformations or phase-change materials. They give a wide range of applications and improve the efficiency of energy systems on both the macro and micro scale. Of course, the technological properties and economic parameters have an impact on the application of the chosen technology. The article presents a comparison of storage parameters or heat storage methods based on different materials with specification of their work parameters or operating costs