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Effective Permeability of Multi Air Gap Ferrite Core 3-Phase Medium Frequency Transformer in Isolated DC-DC Converters
PublicationThe magnetizing inductance of the medium frequency transformer (MFT) impacts the performance of the isolated dc-dc power converters. The ferrite material is considered for high power transformers but it requires an assembly of type “I” cores resulting in a multi air gap structure of the magnetic core. The authors claim that the multiple air gaps are randomly distributed and that the average air gap length is unpredictable at the...
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Unusual divergence of magnetoacoustic beams
PublicationTwo-dimensional magnetosonic beams directed along a line forming a constant angle h with the equilibrium straight magnetic field are considered. Perturbations in a plasma are described by the system of ideal magnetohydrodynamic equations. The dynamics of perturbations in a beam are different in the cases of fast and slow modes, and it is determined by h and equilibrium parameters of a plasma. In particular, a beam divergence may...
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Simulation of the Remanence Influence on the Transient States of the Single-Phase Transformer Including Feedback Preisach Model
PublicationThis paper presents the results of the experimental and simulation investigation concerning the influence of remanence in the core of a single-phase transformer at the no-load transient state. Experimental studies consisted of the discharge of the capacitor through the primary winding at several different values of the residual magnetic flux. The paper presents a model of the transformer test system, taking into account the magnetic...
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Photovoltaic effect in the single-junction DBP/PTCBI organic system under low intensity of monochromatic light
PublicationPhotoelectric properties of the planar ITO/MoO3/DBP/PTCBI/BCP/Ag system were characterized on the basis of short-circuit current, open-circuit voltage and absorption spectra, and current-voltage measurements in the dark and under monochromatic illumination of low intensity. Photovoltaic performance of the system was compared with the performance of ideal semiconductor and excitonic cells of chosen bandgaps. Such analysis shows,...
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Towards spectroscopic monitoring of photoelectrodes: In-situ Raman photoelectrochemistry of a TiO2/prussian blue photoanode
PublicationHere, novel in-situ Raman photoelectrochemical measurements are performed. The obtained results have proved that it is possible to track the progress of a photoelectrochemical reaction that takes place on a semiconducting electrode using the spectroscopic method. As an exemplary system, the Ti/TiO2/Prussian blue electrode is investigated. Since TiO2 is an n-type semiconductor, it cannot act as an efficient anode in dark conditions....
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Frontispiece: Tuning of High Spin Ground State and Slow Magnetic Relaxation within Trimetallic Cyanide‐Bridged {Ni II x Co II 9− x [W V (CN) 8 ] 6 } and {Mn II x Co II 9− x [W V (CN) 8 ] 6 } Clusters
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Finite Element Method Applied in Electromagnetic NDTE: - A Review
PublicationThe paper contains an original comprehensive review of finite element analysis (FEA) applied by researchers to calibrate and improve existing and developing electromagnetic non-destructive testing and evaluation techniques, including but not limited to magnetic flux leakage (MFL), eddy current testing, electromagnetic-acoustic transducers (EMATs). Premium is put on the detection and modelling of magnetic field, as the vast majority...
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The structure, including stereochemistry, of levorin A1
PublicationThe constitution and stereostructure of levorin A1 1, an aromatic heptaeneantifungal antibiotic, was established on the basis of NMR studies, which contained DQFCOSY,ROESY, HSQC and HMBC experiments. Mycosamine moiety was used as an internalchiral probe to determine the absolute configuration of levorin A1 stereogenic centers: 13S,15R, 17S, 18R, 19S, 21R. The relative configuration of the remaining stereogenic centers wasassigned...
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Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon 1H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the absolute...
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previously elaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. The structure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Intramolecular transformation of an antifungal antibiotic nystatin A1 into its isomer, iso-nystatin A1 - structural and molecular modeling studies
PublicationNystatin A1, a polyene macrolide antifungal antibiotic, in a slightly basic or acidic solution undergoes an intramolecular transformation, yielding a structural isomer, the translactonization product, iso-nystatin A1 with lactone ring diminished by two carbon atoms. Structural evidence is provided by advanced NMR and Mass Spectrometry (MS) studies. Molecular dynamics simulations and quantum mechanics calculations gave the insight...
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Absolute configurations of C34 and C35 of antibiotic niphimycin A
PublicationThe relative configurations of four stereogenic centers of the C33-C42 fragment of niphimycin A were assigned as 2S*, 3R*, 4S* and 6S*, based upon (1)H NMR analysis with double-quantum filtered COSY and nuclear Overhauser spectroscopy experiments. These data were then correlated with absolute configurations at C36 and C38 of niphimycin A, which were declared previously as 36S and 38S [3]. This allowed for the assignment of the...
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Stereostructure of mycoheptin A2
PublicationThe absolute configurations of all the stereogenic centers of the antibiotic mycoheptin A2 were established upon previouslyelaborated general procedure, consisting of DQF-COSY, NOESY, ROESY, HSQC and HMBC experiments as major tools. Thestructure of mycoheptin A2 without stereochemistry of its aglycone has been reported before.
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Study of Aliphatic Polyurethanes by the Low-Field 1H NMR Relaxometry Method with the Inversion of the Integral Transformation
PublicationIn this paper, the distributions of the 1H nuclear magnetic resonance (NMR) spin–lattice and spin–spin relaxation times are used to characterize the mobility of different sections of macromolecules of aliphatic polyurethanes and the cross-linking density of polymer chains. The NMR relaxometry method with inversion of integral transformation is applied to study the effect of poly (ethylene glycol) and glycerol phosphate calcium...
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Study of the Effect of Filling Thermoplastic Medical Polyurethane with PVA, PLA or Diatomite on the Relaxation Times Distributions of 1H NMR
PublicationIn this work, to characterize the mobility of diferent sections of the macromole‑ cules of polyurethane (PUR), polyvinyl alcohol (PVA), and polylactic acid (PLA), as well as the density of crosslinks of the polymer chains when using fllers, we used the distributions of spin–lattice and spin–spin relaxation times for the protons. It is shown that the rigidity of the thermoplastic polymers depends on the sizes of the granules of...
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Theoretical analysis of solvent effects on nitrogen NMR chemical shifts in oxazoles and oxadiazoles
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Spectral assignment and proton transfer studies ofN-(R-salicylidene)-1-amino-1-deoxy-d-sorbitols
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The Role of Specific Side Groups and pH in Magnetization Transfer in Polymers
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NMR relaxation enhancement in gels polymerized and cross-linked by ionizing radiation: A new approach to 3D dosimetry by MRI
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The Analysis of Hyperfine Shifts of Mono-Ligand High-Spin Cobalt(II) Pyrazolylborate Complexes
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Deducing 1D concentration profiles from EPR imaging: A new approach based on the concept of virtual components and optimization with the genetic algorithm
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Reaction of bis[bis(tri-tert-butoxysilanethiolato)cadmium(II)] with 3,5-dimethylpyridine - 113Cd NMR Solution study
PublicationAnaliza 113Cd NMR dla reakcji bis[bis(tri-tert-butoksysilanotiolanu)kadmu(II)] z 3,5-dimetylopirydyną została przeprowadzona w roztworze benzenu-d6 i toluenu-d8. Otrzymane wyniki wskazują, że w roztworze istnieje równowaga pomiędzy powstającymi mieszanymi kompleksami kadmu z ligandami siarkowymi i azotowymi.
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Reaction of bis[bis(tri‐tert‐butoxysilanethiolato) cadmium(II)] with 3,5‐dimethylpyridine ‐ 113Cd NMR solution study
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Correlation between the Reactivity and Spectroscopic Properties of N-Substituted Secondary Thioamides. New Intramolecular N• •H+• •N Binding Approach and Proton Complexes Based on Thioamide Ligation
PublicationFrom a comparison of chem. shifts and wavenumbers of several secondary thioamides and amides having monocationic substituents attached to thiocarbamoyl or carbamoyl groups by a polymethylene chain, new intramol. unconventional N···H+···N H bonding effects were discovered. It is argued that the CH2-N rotation is hindered and two +H···NHMe nonequiv. protons occur in a proton spectrum of hydrochloride RCH2C(S)NH(CH2)3NHMe-HCl...
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A new technique with high reproducibility to estimate renal oxygenation using BOLD-MRI in chronic kidney disease
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Monosaccharides as internal probes for the determination of the absolute configuration of 2-butanol
PublicationD-dlukoza, D-mannoza i L-ramnoza zostały poddane reakcji z mieszaniną racemiczną 2-butanolu. Otrzymane w ten sposób glikozydy były analizowane za pomocą spektroskopii NMR, z wykorzystaniem eksperymentów COSY i NOESY. Analiza konformacyjna wiązania glikozydowego (dokonana w oparciu o modelowanie molekularne i heteronuklearne stałe sprzężenia) wraz z analizą sprzężeń dipolowych obserwowanych w widmie NOESY umożliwiła określenie konfiguracji...
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Wojciech Sadowski prof. dr hab. inż.
PeopleWojciech Sadowski (born 2 February 1954 in Ostaszewo, Poland), scientist, engineer, professor at Gdansk University of Technology, specialist in solid state body physics, nanotechnology, optoelectronics. In 1973 he completed his high school education at High School Nicolaus Copernicus in Chelmno. In 1979 he graduate from Leningrad Electrotechnical Institute in Russia (former Soviet Union) with specialism in dielectrics and semiconductors....
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Influence of operation temperature instability on gas sensor performance
PublicationGas sensors based on the semiconducting metal-oxides, such as SnO2, have been found to be very useful for detecting a wide range of gases. The reversible interactions of the gas with the surface of the sensing layer made of semiconducting metal-oxides are responsible for changes of sensor resistance which is usually used as a measure of sensor response. Semiconductor gas sensors are commercially available and applied in numerous...
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Capping ligand initiated CuInS2 quantum dots decoration on, ZnIn2S4 microspheres surface under different alkalinity levels resulting in different hydrogen evolution performance
PublicationSurface distribution of quantum dots (QDs) at the semiconductor matrix caused by synthesis condition (e.g. pH of solution during coupling) could lead to different photocatalytic activity. Thus, achieving an optimal covering of semiconductor matrix by QDs has been challenging. Herein, the influence of the alkalinity level of aqueous decoration medium for the coupling of mercaptoundecanoic acid (MUA) capped CuInS2 quantum dots (CIS)...
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Superconductivity and itinerant ferromagnetism of Y9Co7 probed by ac susceptibility
PublicationThe ac magnetic susceptibility of a single crystal sample of the compound Y9Co7 has been measured in applied dc fields ranging from 0–6.7 kOe by utilizing a tunnel diode resonator circuit. In agreement with previous measurements on this material, a superconducting transition has been observed to occur at TSC ≈ 2.5 K. A broad maximum has been observed in the zero field susceptibility measurements from 2.5 K < T < 8 K and its behavior...
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Wide-field magnetometry using nitrogen-vacancy color centers with randomly oriented micro-diamonds
PublicationMagnetometry with nitrogen-vacancy (NV) color centers in diamond has gained significant interest among researchers in recent years. Absolute knowledge of the three-dimensional orientation of the magnetic field is necessary for many applications. Conventional magnetometry measurements are usually performed with NV ensembles in a bulk diamond with a thin NV layer or a scanning probe in the form of a diamond tip, which requires a...
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Impact analysis of surface roughness of the plate-plate measuring system on resistance torque in interaction with MR fluid
PublicationMagnetorheological (MR) fluids are complex suspensions of magnetic particles in a non-magnetic carrier fluid. They exhibit ‘smart’ properties that enable them to change their rheological parameters in response to a change in the external magnetic field applied. This behavior is used in some engineering solutions, e.g. MR clutches or brakes. For such systems to work correctly, the resistance torque achieved by contact with the...
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Estimation of Broadband Complex Permeability Using SIW Cavity-Based Multimodal Approach
PublicationIn this article, an attractive multimodal substrate integrated waveguide (SIW) based methodology is presented for the characterization of magnetic materials in the broadband microwave frequency. The proposed approach employs a modified feed under-coupled SIW cavity instead of conventional feed over-coupled multiple SIW cavities; it uses the modified closedform expression, developed from the first principle to consider the effect...
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Field-induced suppression of charge density wave in GdNiC2
PublicationWe report the specific heat, magnetic, magnetotransport, and galvanomagnetic properties of polycrystalline GdNiC 2 . In the intermediate temperature region above T N = 20 K, we observe large negative magnetoresistance due to Zeeman splitting of the electronic bands and partial destruction of a charge density wave ground state. Our magnetoresistance and Hall measurements show that at low temperatures a magnetic field-induced transformation from...
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Obrony prac doktorskich na Wydziale Chemicznym
EventsDn. 25.03.2022 r. o godz. 10.00 w Audytorium 1.4 Wydziału Chemicznego PG (budynek nr 5) odbędzie się w trybie hybrydowym publiczna obrona pracy doktorskiej mgr inż. Anny Pancielejko.
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Study of microstress state of P91 steel using complementary mechanical Barkhausen, magnetoacoustic emission, and X-ray diffraction techniques
PublicationThe paper deals with assessment of microstress state of martensite P91 steel using three complementary techniques: mechanical Barkhausen emission, magnetoacoustic emission (MAE), and X-ray diffraction (XRD) profile analysis. Magnetic coercivity Hc and microstructure were investigated with inductive magnetometry and magnetic force microscopy (MFM), respectively. Internal stress level of P91 steel was modified by heat treatment....
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Magnetically recyclable TiO2/MXene/MnFe2O4 photocatalyst for enhanced peroxymonosulphate-assisted photocatalytic degradation of carbamazepine and ibuprofen under simulated solar light
PublicationIn this study, a novel TiO2/Ti3C2/MnFe2O4 magnetic photocatalyst with dual properties, enabling (i) improved photocatalytic degradation with PMS activation under simulated solar light and (ii) magnetic separation after the degradation process in an external magnetic field was developed and applied for the efficient photodegradation pharmaceutically active compounds (PhACs) frequently present in wastewater and surface waters worldwide. MXene...
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A simple model of the trap-assisted recombination with the excitonic Auger mechanism
PublicationWe present a simple model of the trap-assisted recombination combined with the excitonic Auger mechanism. It has been shown that only six independent transitions of electrons and holes should be taken into account to describe a combination of the Shockley–Read–Hall (SRH) recombination with this excitonic process. This is in opposition to a well-known model of the SRH mechanism with the free carriers Auger effect via deep states,...
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KTaO3-based nanocomposites for air treatment
PublicationThe advantage is that photocatalytic methods allow removing VOCs, NOx, SO2, deodorants, and microorganisms at the same system. The new third generation of photoactive materials activated by low powered and low cost irradiation sources (such as LEDs or black fluorescent UV lamps) can be used as photocatalysts in air purification systems. A series of single semiconductors and their nanocomposites combination were prepared using hydrothermal...
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Sharp transitions in low-number quantum dots Bayesian magnetometry
PublicationWe consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement...
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Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublicationThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a single-phase transformer with a core made of ferrite I-core elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...
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Series Passive Compensation of Common Mode Voltage in Multilevel Inverter Drives
PublicationThis paper presents an approach to the problem of a magnetic saturation of CM chokes that accompanies the method of passive compensation of a common mode (CM) voltage in an inverter drive system. Measurements have been provided in a drive system including multilevel inverters and the filter having sinusoidal output voltages and zero CM voltage. The theoretical analysis and experimental results show that the problem with magnetic...
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The homometallic warwickite V 2 OBO 3
PublicationThe synthesis, structure and elementary magnetic characterization of the homometallic warwickite V2OBO3 are reported. The material adopts the orthorhombic warwickite structure type at room temperature, space group Pnma (No. 62) with lattice parameters a = 9.2317(1) Å, b = 3.1172(1) Å, and c = 9.5313(1) Å. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements show anomalies near 35 K,...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublicationThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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Potential Skyrmion Host Fe(IO3)3: Connecting Stereoactive Lone-Pair Electron Effects to the Dzyaloshinskii-Moriya Interaction
PublicationMagnetic skyrmions, which are topologically distinct magnetic spin textures, are gaining increased attention for their unique physical properties and potential applications in spintronic devices. Here we present a design strategy for skyrmion host candidates based on combinations of magnetic spin, asymmetric building units having stereoactive lone-pair electrons, and polar lattice symmetry. To demonstrate the viability of the proposed...
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X-ray diffraction (XRD) and particle size distribution (PSD) data of iron oxide (Fe3O4) - magnetite particles
Open Research DataDataset presenting X-ray diffractogram and particle size distribution of nanomagnetite (Fe3O4) iron oxide particles purchased from Sigma Aldrich (637106).X-ray diffraction study was performed with a PRO X-ray diffractometer (X’Pert PRO Philips diffractometer, Co. Ka radiation, Almelo, Holland), while PSD was determined using laser diffraction technique...
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Olga Ciupak mgr inż.
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Electric field maps of an astable multivibrator in frequency range from 30 MHz to 3 GHz
Open Research DataThe data presents a result of near field measurements of electromagnetic emissions radiated from the PCB of a small electronic device. An efficient method of modelling the magnetic and electric field emissions is the measurements in the near field using electric and magnetic probes. The attached files contain electric field maps created on based measurements...
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Optical Magnetometry Based on Nanodiamonds with Nitrogen-Vacancy Color Centers
PublicationNitrogen-vacancy color centers in diamond are a very promising medium for many sensing applications such as magnetometry and thermometry. In this work, we study nanodiamonds deposited from a suspension onto glass substrates. Fluorescence and optically detected magnetic resonance spectra recorded with the dried-out nanodiamond ensembles are presented and a suitable scheme for tracking the magnetic-field value using a continuous...
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Organic pollutants photodegradation increment with use of TiO2 nanotubes decorated with transition metals after pulsed laser treatment
PublicationAmong various titanium(IV) oxide (TiO2, titania) structures, 1D nanotubes (TiO2 NTs) produced during the two-electrode anodization process, are extensively utilized in sensors or supercapacitors as well as in photo(electro)catalytic water splitting. However, due to wide bandgap and fast electron-hole recombination additional modifications, mostly concerned on materials surface, are required. According to the recent research, TiO2...