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Badanie wpływu składowej stałej i kąta opóźnienia zapłonu prądu różnicowego na czułość wyłączników różnicowoprądowych typu AC i A
PublikacjaW referacie przedstawiono wyniki badań działania wyłączników różnicowoprądowych typu AC i A przy różnych prądach różnicowych jednokierunkowych i przy prądach dwukierunkowych o różnym kącie opóźnienia zapłonu. Jak wynika z badań czułość wyłączników różnicowoprądowych istotnie zależy od kształtu przebiegu prądu różnicowego. Przy prądach różnicowych jednokierunkowych prąd zadziałania wzrasta tym bardziej, im bardziej prąd różnicowy...
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Badanie wpływu składowej stałej i kąta opóźnienia zapłonu prądu różnicowego na czułość wyłączników różnicowoprądowych typu AC i A
PublikacjaW artykule przedstawiono wyniki badań działania wyłączników różnicowoprądowych typu AC i A przy różnych prądach różnicowych jednokierunkowych i przy prądach dwukierunkowych o różnym kącie opóźnienia zapłonu. Jak wynika z badań, czułość wyłączników różnicowoprądowych istotnie zależy od kształtu przebiegu prądu różnicowego. Przy prądach różnicowych jednokierunkowych prąd zadziałania wzrasta tym bardziej, im bardziej prąd różnicowy...
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Czułość wyłączników różnicowoprądowych o wyzwalaniu typu AC i A przy znamionowej i podwyższonej częstotliwości prądu różnicowego.
PublikacjaArtykuł przedstawia analizę działania powszechnie stosowanych wyłączników różnicowoprądowych o wyzwalaniu niezależnym od napięcia sieci przy znamionowej i podwyższonej częstotliwości prądu różnicowego. Zaprezentowano konstrukcje obecnie stosowanych wyłączników i charakterystyki ich działania w warunkach określonych przez odpowiednie normy przedmiotowe oraz w warunkach odbiegających od znormalizowanych, a które mogą pojawić się...
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Feasibility study of inductor coupling in three-level neutral-point-clamped quasi-Z-source DC/AC converter
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Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue
PublikacjaThis paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and...
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Badania spękań niskotemperaturowych podbudów a AC WMS na nowobudowanej autostradzie A1 w Polsce. Część 1 - Badania terenowe i laboratoryjne
PublikacjaW artykule przedstawiono problem niskotemperaturowych spękań poprzecznych, które powstały na podbudowach z betonu asfaltowego o wysokim module sztywności AC WMS. Liczne spękania niskotemperaturowe powstały na analizowanych podbudowach AC WMS podczas okresu zimowego w 2012 r. zanim została zakończona cała konstrukcja nawierzchni. Spękania powstały zarówno na połączeniach technologicznych, jak i pomiędzy nimi. Problem taki nie wystąpił...
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Power Hardware-In-the-Loop Approach for Autonomous Power Generation System Analysis
PublikacjaThe article presents the Power Hardware-In-the-Loop (PHIL) dynamic model of a synchronous generator of 125 kVA for autonomous power generation system analysis. This type of system is typically composed of electrical energy sources in the form of several diesel generator units with synchronous machines, the main distribution switchboard and different loads. In modern power distribution systems, the proposed power management strategies...
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A comprehensive evaluation of mimosa extract as a corrosion inhibitor on AA6060 alloy in acid rain solution: part I. Electrochemical AC methods
PublikacjaThe inhibition effect of mimosa extract on the corrosion of AA6060 aluminum alloy in acid rain solution was investigated by electrochemical impedance spectroscopy and dynamic electrochemical impedance spectroscopy (DEIS). All the studied electrochemical parameters showed good corrosion inhibitive characteristics with respect to the aluminum alloy in the tested solution. Inhibitor efficiency increased with the concentration and...
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INTERNAL DETERMINANTS OF FIRMS’ INNOVATIVENESS
PublikacjaThis article presents an analysis of the determinants of a firm’s innovativeness deriving from its internal potential and characteristics. The analysis is based on research carried out on 1355 firms that applied for public subsidies from the Innovative Economy Operational Program in 2014. The methods applied are logit regression, comparative analysis and literature review. The analysis is structured ac- cording to Bielski’s model...
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Badania spękań niskotemperaturowych podbudów z AC WMS na nowobudowanej autostradzie A1 w Polsce. Część 2 - Analiza przyczyn powstania spękań nawierzchni.
PublikacjaW artykule przedstawiono problem niskotemperaturowych spękań poprzecznych, które powstały na nowo budowanych podbudowach z betonu asfaltowego o wysokim module sztywności AC WMS. Liczne spękania niskotemperaturowe powstały na analizowanych podbudowach AC WMS podczas okresu zimowego w 2012 r., zanim cała konstrukcja nawierzchni została ukończona. Spękania powstały zarówno na połączeniach technologicznych, jak i między nimi. Problem...
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The extended model predictive-sliding mode control of three-level AC/DC power converters with output voltage and load resistance variations
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Sterowanie stopniem wejściowym izolowanego wielopoziomowego przekształtnika kaskadowego DC-AC w napędzie EZT zasilanym z sieci trakcyjnej 3kV
PublikacjaW artykule przedstawiono wybraną problematykę sterowania wielopoziomowego przekształtnika DC-DC stanowiącego stopień wejściowy przekształtnika napędowego, przeznaczonego do napędów elektrycznych zespołów trakcyjnych (EZT). Sterowanie napędem trakcyjnym powinno uwzględniać właściwości sieci trakcyjnej 3kV DC: skokowe zmiany napięcia i przerwy w zasilaniu, m.in. spowodowane przejazdem odbieraka prądu przez izolatory sekcyjne. Proponowany...
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Investigation of magnetic order in a new intermetallic compound Nd2PtGe3
PublikacjaIn the present study we report a successful synthesis of the new intermetallic compound Nd2PtGe3 by an arc-melting method. The powder X-ray diffraction analysis indicates that this compound crystallizes in an disordered variant of the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a = 4.2455 Å and c = 4. 1933 Å. The compound exhibits a cluster-glass transition below Tf = 2.9 K, characterized through ac...
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Fault Loop Impedance Measurement in Circuits Fed by UPS and Principle of Safety Protection
PublikacjaThis paper indicates a significant problem of uncertainty of fault loop impedance (FLI) measurement in circuits powered from uninterruptible power supply (UPS) (double-conversion AC-DC-AC). The correctly determined value of this impedance, related to the short-circuit current disconnection time and to the reference value, is one of the most important elements that determines the approval of an electrical installation and its receivers...
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Low temperature broad band dielectric spectroscopy of multiferroic Bi6Fe2Ti3O18 ceramics
PublikacjaIn the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18 (BFTO) Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz – 10MHz) within the temperature range ΔT=-100°C – 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found...
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Conversion of waste biomass to designed and tailored activated chars with valuable properties for adsorption and electrochemical applications
PublikacjaWaste biomass, a renewable energy source, is inexpensive material that has great potential in sorp-tion and electrochemical application. The selected waste materials (corncobs, coconut shells, wal-nuts, and pistachio husks) allow to close the production cycle and enable material recycling, which are important aspects in the hierarchy of waste management. The proposed methodology for pro-duction and activation of biochars can be...
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ANALYSIS AND OPTIMIZATION OF ELECTRIC VEHICLE CHARGING PROCESSES IN TRANSACTIVE ENERGY SYSTEMS
PublikacjaThe implementation of smart charging of electric vehicles allows operators of local power networks and electricity suppliers to implement new business models for the interaction of electric vehicles with the network. In addition to the optimal selection of Microgrid capacities when charging electric vehicles, it is also important to use different charging methods. To satisfy the interests of all participants of local systems from...
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Conversion of waste biomass into activated carbon and evaluation of environmental consequences using life cycle assessment
PublikacjaIn this article, activated carbon was produced from Lantana camara and olive trees by H3PO4 chemical activation. The prepared activated carbons were analyzed by characterizations such as scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared spectroscopy. H3PO4 is used as an activator agent to create an abundant pore...
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Comparative Analysis of Phytochemical Profiles and Selected Biological Activities of Various Morphological Parts of Ligustrum vulgare
PublikacjaLigustrum vulgare (LV), widely cultivated in Europe and often used in hedges, has been histori-cally recognized in folk medicine for its potential health benefits. This study focused on exploring the untargeted identification of secondary metabolites in ethanol extracts (70% v/v) from differ-ent morphological parts (young shoots, leaves, flowers and fruits) of LV at various stages of plant development, using ultra-high-performance...
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Comparison of low-temperature cracks intensity on pavements with high modulus asphalt concrete and conventional asphalt concrete bases
PublikacjaHigh modulus asphalt concrete (HMAC) base courses provide very good resistance to rutting and fatigue but they can increase the risk of low-temperature cracking as compared with conventional asphalt concrete (AC). The article presents the comparison of these two road materials in terms of low-temperature cracking. The statistical method based on the ordered logistic regression model was used. The analysis was based on results of...
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Development of an emulation platform for synchronous machine power generation system using a nonlinear functional level model
PublikacjaThe article presents the Power Hardware in the Loop (PHIL) approach for an autonomous power system analysis based on the synchronous generator model incorporating magnetic saturation effects. The model was prepared in the MATLAB/Simulink environment and then compiled into the C language for the PHIL platform implementation. The 150 kVA bidirectional DC/AC commercial-grade converter was used to emulate the synchronous generator....
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Technological capability dynamics through cluster organizations
PublikacjaPurpose – The purpose of the paper is to portrait how members of cluster organizations (COs) perceive the role of COs in enabling them to accumulate technological capability (TC) significant for their innovation. Design/methodology/approach – The authors report the findings from their qualitative study based on an analysis of four COs. The organizational inertia and absorptive capacity (AC) theories are the theoretical underpinning...
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Concept of Wireless Low-Voltage DC Socket for the Residential House Application
PublikacjaThe proposed research is devoted to the comprehensive theoretical and experimental study of the concept of the wireless low power dc socket for residential applications. The main goal of this work is to provide safe dc source for residential customers at power level which is enough in order to supply all typical appliances without power factor correctors. Such types of devices can be already connected to the dc grid and decoupled...
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Implementation of constant component filter in measurements of random telegraph signal noise
PublikacjaNoise is generated in all semiconductor devices. The intensity of these fluctuations depends on used elements, manufacturing process, operating conditions and device type. The result noise is a superposition of different kinds of fluctuations like thermal noise, generation-recombination noise, 1/f noise, shot noise and Random Telegraph Signal (RTS) noise. The last one, RTS noise is observed as nonstationary impulse fluctuations....
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Application of Traction Supply System for Charging Electric Cars
PublikacjaThe development of electromobility involves the development of electric cars charging infrastructure. The increase of the number of chargers poses new demands for the AC power grid, especially in regard to its capacity of delivering high peak power. As an alternative for the public AC power grid, urban electrified transportation systems (trams, trolleybuses, and metro) can be used for supplying electric cars chargers. The article...
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Determination of pitting corrosion stage of stainless steel by galvanodynamic impedance spectroscopy
PublikacjaThis paper investigates the methodology for differentiation of multistep process of pitting corrosion of AISI 304 stainless steel in the environment of iron (III) chloride. Measurements were performed using Galvanodynamic Electrochemical Impedance Spectroscopy (GDEIS). Application of this methodology allowed monitoring of natural corrosion process without external current (IDC = 0A) nor potential perturbation of the system. Applied...
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Synthesis, structure and physical properties of new intermetallic spin glass-like compounds RE2PdGe3 (RE = Tb and Dy)
PublikacjaNew intermetallic compounds Tb2Pd1.25Ge2.75 and Dy2Pd1.25Ge2.75 have been synthesized using the arc-melting method. The crystallographic structure and magnetic, electronic transport, and thermal properties are reported. The crystal structure obtained from powder x-ray diffraction analysis suggests that these compounds crystallize in the AlB2-type structure (space group P6/mmm, no. 191) with lattice parameters a = 4.228 53(5)/4.230 54...
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Technique to improve CMRR at high frequencies in CMOS OTA-C filters
PublikacjaIn this paper a technique to improve the common-mode rejection ratio (CMRR) at high frequencies in the OTA-C filters is proposed. The technique is applicable to most OTA-C filters using CMOS operational transconductance amplifiers (OTA) based on differential pairs. The presented analysis shows that a significant broadening of CMRR bandwidth can be achieved by using a differential pair with the bodies of transistors connected to...
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Testing of low temperature behaviour of asphalt mixtures in bending creep test
PublikacjaThe paper presents a method of bending beam test and its importance for evaluation of asphalt mixtures behaviour at low temperatures. Two types of asphalt mixtures: asphalt concrete AC with normal paving grade bitumen and stone mastic asphalt SMA with SBS-modified bitumen were tested. Long-term oven ageing (LTOA) test was also used in the laboratory according to SHRP procedure. The Burgers model was applied and rheological parameters...
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Offshoring and outsourcing in Visegrad countries, Advantages and disadvantages.
PublikacjaOutsourcing and offshoring are getting more and more popular in the “new EU” coun-tries. They constitute very attractive venues for more developed EU countries to outsource or offshore their business activities. Authors of the article have investigated the advantages and disadvantages of locating outsourcing activities in each of the Visegrad (V4) countries. The authors have studied macroeconomic factors based on the reports of...
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Evaluation of Asphalt Mixture Low-Temperature Performance in Bending Beam Creep Test
PublikacjaLow-temperature cracking is one of the most common road pavement distress types in Poland. While bitumen performance can be evaluated in detail using bending beam rheometer (BBR) or dynamic shear rheometer (DSR) tests, none of the normalized test methods gives a comprehensive representation of low-temperature performance of the asphalt mixtures. This article presents the Bending Beam Creep test performed at temperatures from −20...
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Appendix E
PublikacjaThe advance of variable speed drives systems (VSDs) engineering highlights the need of specific technical guidance provision by electrical machines and drives manufacturers, so that such applications can be properly designed to present advantages in terms of both energy efficiency and expenditure. This book presents problems and solutions related to inverter-fed electrical motors. Practically orientated, the book describes the...
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Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables
PublikacjaThis paper presents the space charge impact on the inception and propagation of electrical trees in cross-linked polyethylene (XLPE) insulation via simulations and experimentation. A 3D finite element analysis (FEA)-based modeling is proposed to simulate electrical trees via a needle embedded on the XLPE insulation. The proposed FEA model demonstrates the influence of the space charge magnitude and polarity on the initiation of...
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Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring
PublikacjaThe main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University...
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The Conceptual Research over Low-Switching Modulation Strategy for Matrix Converters with the Coupled Reactors
PublikacjaIn this paper, different Pulse Width Modulation (PWM) strategies for operating with a low-switching frequency, a topology that combines Conventional Matrix Converters (CMCs), and Coupled Reactors (CRs) are presented and discussed. The principles of the proposed strategies are first discussed by a conceptual analysis and later validated by simulation. The paper shows how the combination of CMCs and CRs could be of special interest...
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Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
PublikacjaSodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between...
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A Proposed Machine Learning Model for Forecasting Impact of Traffic-Induced Vibrations on Buildings
PublikacjaTraffic-induced vibrations may cause various damages to buildings located near the road, including cracking of plaster, cracks in load-bearing elements or even collapse of the whole structure. Measurements of vibrations of real buildings are costly and laborious. Therefore the aim of the research is to propose the original numerical algorithm which allows us to predict, with high probability, the nega-tive dynamic impact of traffic-induced...
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Critical Review on Robust Speed Control Techniques for Permanent Magnet Synchronous Motor (PMSM) Speed Regulation
PublikacjaThe permanent magnet synchronous motor (PMSM) is a highly efficient energy saving machine. Due to its simple structural characteristics, good heat radiation capability, and high efficiency, PMSMs are gradually replacing AC induction motors in many industrial applications. The PMSM has a nonlinear system and lies on parameters that differ over time with complex high-class dynamics. To achieve the excessive performance operation...
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Efficient Gradient-Based Algorithm with Numerical Derivatives for Expedited Optimization of Multi-Parameter Miniaturized Impedance Matching Transformers
PublikacjaFull-wave electromagnetic (EM) simulation tools have become ubiquitous in the design of microwave components. In some cases, e.g., miniaturized microstrip components, EM analysis is mandatory due to considera¬ble cross-coupling effects that cannot be accounted for otherwise (e.g., by means of equivalent circuits). These effects are particularly pronounced in the structures in¬volving slow-wave compact cells and their numerical...
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Glyceraldehyde - 3 - phosphate dehydrogenase gen from Amanita citrina. Ac-cession AJ532582, 2002 GenBank NCBI [on line].**2002 [cytowany 07.01.03]. Dostępny: http://www.ncbi.nml.nih.gov Sekwencja genu kodującego dehydrogenzę aldehydu - 3 - fsfoglicerynowego dla muchomora cytrynowego (Amanita citrina).
PublikacjaPo raz pierwszy ustalono sekwencję nukleotydową fragmentu genu gpd (dehydro-genazy aldehydu - 3 - fosfoglicerynowego) dla muchomora cytrynowego (Amanitacitrina), pozwoli to na ustalenie sekwencji starterów umożliwiających wykry-wanie grzybów tego gatunku za pomocą techniki PCR.
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Managerial Energy in Sustainable Enterprises: Organizational Wisdom Approach
PublikacjaThe circular economy (CE) as an idea involves applying the concept of sustainable development that has been gaining worldwide support. This shift in perception of energy and resource-use from its linear to circular forms creates a specific business environment, which constitutes the subject of this research. This article aims to analyze the impact of a manager’s energy on organizational wisdom, focusing on its circular business...
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Niekorzystny wpływ przekształtnikowego zasilania PWM na silniki asynchroniczne trakcyjne
PublikacjaThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
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Badania niskotemperaturowego twardnienia fizycznego betonu asfaltowego i mieszanki SMA
PublikacjaArtykuł przedstawia badania twardnienia fizycznego w czasie izotermicznego przechowywania betonu asfaltowego AC i mieszanki SMA w temperaturze -20st.C. Stwierdzono wyraźny wzrost modułu sztywności i brak zmian wytrzymałości na pośrednie rozciąganie w przypadku obu mieszanek. Proces twardnienia fizycznego różnił się dla AC i SMA.
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Phase I and phase II metabolism simulation of antitumor-active 2-hydroxyacridinone with electrochemistry coupled on-line with mass spectrometry.
PublikacjaHere, we report the metabolic profile and the results of associated metabolic studies of 2-hydroxyacridinone (2-OH-AC), the reference compound for antitumor-active imidazo- and triazoloacridinones. Electrochemistry coupled with mass spectrometry was applied to simulate the general oxidative metabolism of 2-OH-AC for the first time. The reactivity of 2-OH-AC products to biomolecules was also examined. The usefulness of the electrochemistry...
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Analiza lepkosprężysta nawierzchni drogowych z zastosowaniem betonu asfaltowego konwencjonalnego i o wysokim module sztywności
PublikacjaRozprawa doktorska dotyczy lepkosprężystego zachowania się konstrukcji nawierzchni drogowych z zastosowaniem betonów asfaltowych konwencjonalnych AC i o wysokim module sztywności AC-WMS. Składa się z trzech części. Pierwsza część dotyczy zaprojektowania i właściwości mieszanek mineralno-asfaltowych, zróżnicowanych pod względem krzywych uziarnienia i rodzaju asfaltu. Przedstawiono wyniki badania odporności na koleinowanie oraz właściwości...
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Spectroscopic and magnetic studies of highly dispersible superparamagnetic silica coated magnetite nanoparticles
PublikacjaSuperparamagnetic behavior in aqueously well dispersible magnetite core-shell Fe3O4@SiO2 nanoparticles is presented. The magnetic properties of core-shell nanoparticles were measured with use of the DC, AC magnetometry and EPR spectroscopy. Particles were characterized by HR-TEM and Raman spectroscopy, showing a crystalline magnetic core of 11.5 ± 0.12 nm and an amorphous silica shell of 22 ± 1.5 nm in thickness. The DC, AC magnetic...
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Tuning of food wastes bioavailability as feedstock for bio-conversion processes by acoustic cavitation and SPC, SPS, or H2O2 as external oxidants
PublikacjaThe growing amount of food wastes makes them a suitable source for the generation of bioproducts through anaerobic digestion. Appropriate hydrolysis of the feedstock can enhance the efficiency of production of desired products. In this work, acoustic cavitation (AC) was employed as a pretreatment method to enhance hydrolysis stage by the modification of model (potato-based) food waste for increase in soluble chemical oxygen demand...
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Wpływ konfiguracji elektrod pomiarowych oraz parametrów pomiaru na EDR
PublikacjaW pracy przebadano wplyw wybranych konfiguracji elektrod na jakość uzyskiwanego sygnału EDR. Analizie poddane zostały również częstotliwość próbkowania sygnału EKG i rozdzielczość przetwornika AC/DC. Optymalną konfiguracją elektrod jest odprowadzenie kończynowe pierwsze. Minimalne parametry układu pomiarowego do uzyskania wysokiej jakości sygnału EDR, to częstotliwość probkowania 2,5kHz oraz 14-bitowy przetwornik AC-DC.
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Hydrogen Production via Biomethane Reforming in DBD Reactor
PublikacjaProduction of hydrogen from CH4:CO2 (70%:30%) mixture simulating dry biogas in a DBD reactor supplied with AC of 1.0-2.0 kHz or nanosecond negative pulses is presented. We have found that hydrogen production and methane conversion degree increase linearly with discharge power in the range of up to 50 W. Nanosecond voltage pulses are much more efficient in hydrogen production than sine AC voltage
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Chemical and biological stability of polyene macrolides
PublikacjaThe polyene macrolide antibiotics have been used in an-tifungal therapy since first o f them were discovered in 1950's. Up to now, four polyene macrolides are being used in medical practice, namely amphotericin B, nystatin, candi-cidin and pimaricin.The antifungal activity and mode of ac-tion of polyene macrolides is determined by their structure, chemical and physical properties.The main fragment of polyene...