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Search results for: copper
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Macroscopic examination of CuNiFeR pipeline
Open Research DataCopper and nickel alloys called cunifers (Cu, Ni, Fe and R – rest of alloy elements) have found wide application in the production of ship pipeline components in contact with sea water, such as, for example, the main engine cooling system. These alloys are characterized by a very high corrosion resistance, which is ensured by appropriately carried out...
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Increasing efficiency of technological process by limiting impact of corrosive environment on operation of spiral classifiers
PublicationMost of the technological operations related to the preparation of the output to be enriched and to the production of the final copper concentrate take place with the use of water environment. Water management, besides using innovative technical and technological solutions, is a significant factor in the whole copper ore enrichment process. Mine water resources and surface water of the tailing pond named "Żelazny Most" are the...
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Annealing Rate as a Crucial Parameter Controlling the Photoelectrochemical Properties of AuCu Mosaic Core–Shell Nanoparticles
PublicationThermal processing is an essential step during the synthesis of various metal nanostructures and for tailoring their morphology, optical, and electrochemical properties. Herein, a profound impact of the annealing rate and time on photoactivity of gold–copper nanostructures by changes in the position and alignment of energy levels and surface states is reported. AuCu nanoparticles (NPs) are fabricated by sputtering of thin metal...
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Resonator-Loaded Waveguide Notch Filters with Broad Tuning Range and Additive-Manufacturing-Based Operating Frequency Adjustment Procedure
PublicationThis article presents a new class of ring-resonator-loaded waveguide notch filters with a broad tuning range, low cost, and improved performance. The proposed approach employs a comple-mentary asymmetric split ring resonator coupled to a microstrip transmission line and excited in a rectangular waveguide. An equivalent circuit model is proposed to explain the working principle of the proposed notch filter. The adjustment of the...
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Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublicationThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
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Synteza i badania strukturalne związków kompleksowych miedzi(I) i rtęci(II) z wybranymi ligandami tioamidowymi
PublicationPrzedstawiona rozprawa doktorska poświęcona jest związkom tiokarbonylowym (wybranym tioamidom i tiomocznikom) oraz ich połączeniom kompleksowym z halogenkami miedzi(I) i rtęci(II). Istota i cel takich badań przedstawione są we wstępie pracy. W części teoretycznej opisane zostały kluczowe pierwiastki wchodzące w skład syntezowanych związków kompleksowych (siarka, miedź i rtęć), jak również tioamidy i tiomoczniki. Szczególna uwaga...
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Tensile test of part of CuNiFeR pipeline
Open Research DataCopper and nickel alloys called cunifers (Cu, Ni, Fe and R – rest of alloy elements) have found wide application in the production of ship pipeline components in contact with sea water, such as, for example, the main engine cooling system. These alloys are characterized by a very high corrosion resistance, which is ensured by appropriately carried out...
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Properties of chitosan/CuNPs coatings electrophoretically deposited on TiO2 nanotubular oxide layer of Ti13Zr13Nb alloy
PublicationCoatings based on chitosan/CuNPs (chit/CuNPs) were obtained by a one-step electrophoretic deposition (EPD) on nanotubular oxide layer of Ti13Zr13Nb alloy. The deposition was carried out for 1 min applying voltages of 10 and 20 V with and without the addition of dispersing agent (Polysorbate 20) to the suspension. The coatings obtained for the lower voltage were more uniform than for the higher voltage. By adding a dispersing agent,...
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Phytoavailability of potentially toxic elements from industrially contaminated soils to wild grass
PublicationTopsoil and grass samples from 14 sites located in different distances from three copper mining factories and a copper smelter were collected in Srednogorie, Bulgaria. The paper discusses results of studies on the mobility of potentially toxic elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Zn) from contaminated soils to wild grass Cynodon dactylon in terms of transfer (TF: soil to plant) and phytoavailability (PF: EDTA (ethylenediaminetetraacetic...
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Experimental investigation of forced convection of water-Al2O3 nanofluids inside horizontal tubes,
PublicationIn this paper, forced convection of water–Al2O3 nanofluids inside horizontal copper tube is studied experimentally. Experiments were conducted for three, i.e. 0.1%, 1% and 5% nanoparticle mass concentrations under transition and turbulent flow regimes. Average heat transfer coefficients and pressure drop values were determined and compared to distilled water. Enhancement of heat transfer for lower nanoparticle concentration and...
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Improvements to the two-phase sandwich method for calculating the melting points of pure metals
PublicationThe thermophysical properties of metal alloys are often investigated via molecular dynamics (MD) simulations.An exact and reliable estimation of the thermophysical parameters from the MD data requires a properly and carefullyelaborated methodology. In this paper, an improved two-phase sandwich method for the determination of the metal meltingtemperature is proposed, based on the solid-liquid equilibrium theory. The new method was...
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Experimental Investigations on the Influence of Coil Arrangement on Melting/Solidification Processes
PublicationThe latent heat thermal energy storage units are very popular because of their high energy density and almost close to constant temperature during the charging/discharging. In the present study has been proposed new shell-and-coil geometry with a shifted coil position to enhance the performance of phase change thermal magazine. The experimental investigations have been performed both for the melting and solidification process of...
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Near Field Coupled Wireless Microwave Sensor
PublicationThis paper presents a wireless planar microwave sensor operating at industrial scientific and medical (ISM) frequency for the detection of dielectric materials. The microwave sensor consists of a reader (ground defected microstrip coupled line) and a passive tag where a complementary split-ring resonator (CSRR) is made on the commercially available copper-foil. The CSRR is a peel-off type tag that is excited using the near field...
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An inclination in Thermal Energy Using Nanoparticles with Casson Liquid Past an Expanding Porous Surface
PublicationPhysical aspects of inclined MHD nanofluid towards a stretching sheet embedded in a porous medium are visualized. Two types of nanoparticles are used named as copper and alumna dioxide with water as base fluid. Similarity transformations are used to convert the partial differential equations into the set of ordinary differential equation. Closed solutions are found to examine the velocity and the temperature profiles. It is examined...
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Near-Field Wireless Sensing of Plastics and Papers Using Frugal Peel-Off Passive Tag
PublicationThis article presents a novel frugal approach of testing plastics and papers using a near-field microwave sensing technique with a peel-off tag. The proposed sensing technique involves two electrical entities: the sensor, which may be regarded as a reader, and a disposable tag. The reader is a modified design of a gap-coupled microstrip line (GCML) sensor, while the passive tag is a standard double-ring complementary split-ring...
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On the mechanism of photocatalytic reactions on CuxO@TiO2 core–shell photocatalysts
PublicationTitania (titanium(IV) oxide) is a highly active, stable, cheap and abundant photocatalyst, and is thus commonly applied in various environmental applications. However, two main shortcomings of titania, i.e., charge carrier recombination and inactivity under visible-light (vis) irradiation, should be overcome for widespread commercialization. Accordingly, titania has been doped, surface modified and coupled with various ions/compounds,...
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EMI mitigation of GaN power inverter leg by local shielding techniques
PublicationThis paper presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common mode (CM) current noise at converter’s DC input. The research study is conducted for 650V Enhancement mode Gallium Nitride (GaN) power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce...
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Biological and mechanical research of titanium implants covered with bactericidal coating
PublicationThe paper concerns the biological and mechanical properties of titanium implants with an antibacterial coating. The Ti13Zr13Nb alloy samples were coated with hydroxyapatite (HAp) coatings using the electrophoretic deposition technique (EPD). Subsequently, the surface of the samples was modified with silver, copper, and nickel nanoparticles by the immersion method. Different titanium sample types (i.e. HAp-only and nanometals-enriched...
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New heterometallic Co/Zn, Ag/Co, and Ag/Zn imidazolates: structural characterization and catalytic activity in the oxidation of organic compounds
PublicationNanocrystalline powders of monometallic and bimetallic imidazolates of Co, Zn, and Ag were produced by a reaction carried out in water. The powders were characterized by powder X-ray diffraction and the crystal structures of new compounds Ag2ZnIm4 and Ag2CoIm4 (Im = imidazolate) were solved. Heterometallic Co/Zn imidazolates showed the standard ZIF-8 crystal structure while Ag/Zn and Ag/Co systems were isostructural with the copper...
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Ultrasonic-assisted Electrodeposition of Cu-Sn-TiO2 Nanocomposite Coatings with Enhanced Antibacterial Activity
PublicationCopper-based coatings are known for their high antibacterial activity. In this study, nanocomposite Cu–Sn–TiO2 coatings were obtained by electrodeposition from an oxalic acid bath additionally containing 4 g/dm3 TiO2 with mechanical and ultrasonic agitation. Ultrasound treatment was performed at 26 kHz frequency and 32 W/dm3 power. The influence of agitation mode and the current load on the inclusion and distribution of the TiO2...
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Structural optimization of microjet array cooling system
PublicationThe single phase heat transfer from an upward facing, horizontal copper surface to arrays of impinging water jets was experimentally investigated. Experimental configuration allows for a free-surface unconfined jets flow. Square nozzles 50 × 100 μm arranged in four different geometries were used. Additionally, for the set of two jets array geometry was varied by adjusting the nozzle to nozzle distance. The area averaged heat transfer...
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Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability
PublicationTitanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel coreinterlayer- shell TiO2 magnetic photocatalysts modified with metal nanoparticles...
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Statistics of AFM current-voltage curves
Open Research DataMapping surface electrical conductivity offers enormous cognitive possibilities regarding the structure and properties of modern materials. The technique invented for this purpose (Conductive AFM) by Murrel's team and colleagues allows independent monitoring of the local conductivity of materials in correlation with the topographic profile. The mentioned...
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Functionalization of graphene oxide coatings with phosphorus atoms and their corrosion resistance in sodium chloride environment
PublicationIn this work, we compared corrosion resistance of graphene oxide, and phosphorus functionalized reduced graphene oxide coatings obtained as a result of electrophoretic deposition on the copper substrate. Doping graphene oxide with phosphorus atoms was performed by a hydrothermal method in the presence of different amounts of phosphoric acid. Structural studies confirmed the insertion of phosphorus atoms into the graphene oxide...
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Fabrication and photoactivity of organic-inorganic systems based on titania nanotubes and PEDOT containing redox centres formed by different Prussian Blue analogues
PublicationHerein, the heterojunction composed of an inorganic substrate: ordered hydrogenated titania nanotubes (H-TiO2NTs) and a deposited organic film: poly(3,4-ethylenedioxythiophene) (PEDOT) is reported. The conducting polymer is modified with different transition metal haxacyanoferrates (Mehcf), wherein as metal: copper, iron, cobalt and nickel are introduced. The presence of various metal centres provides characteristic redox activity...
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Chromogenic azomacrocycles with imidazole residue: Structure vs. properties
PublicationNew diazo macrocycles linked by hydrocarbon chain bearing imidazole or 4-methylimidazole residue have been synthetized with satisfactory yield (24–55%). The structure of macrocycles was confirmed by X-ray analysis and spectroscopic methods (1H NMR, MS, FTIR). Metal cation complexation studies were carried out in acetonitrile and acetonitrile-water system. It was found that azomacrocyles form triple-decker complexes with lead(II)....
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The study on possibilities of recovery non-magnetic fraction by utilisation the magnetic separation technology in conditions of KGHM Polska Miedz S.A. division of concentrators = Próby odzysku frakcji niemagnetycznej metodą separacji magnetycznej w warunkach KGHM Polska Miedź S.A. Oddział Zakłady Wzbogacania Rud
PublicationW referacie przybliżono wyniki badań prowadzonych w kierunku określenia możliwości odzysku frakcji niemagnetycznej i słabomagnetycznej ze strumieni materiałowych O/ZWR, poprzez wykorzystanie metody separacji magnetycznej. Przeprowadzony cykl badawczy obejmował analizę występowania frakcji magnetycznej i związanej z nią frakcji niemagnetycznej w obiegach technologicznych w Rejonie ZWR Lubin, oraz możliwości ich odzysku. Uzyskane...
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Redox property switching in MOFs with open metal sites for improved catalytic hydrogenation performance
PublicationIn this study, a decompression-thermalization strategy was utilized for a Cu-containing metal-organic framework (MOF) to tune its redox and catalytic hydrogenation properties. Remarkably, at just 120 °C, open metal sites (OMSs) were successfully constructed by removing coordinated solvent molecules to generate the daughter MOF-120. The tailored redox property of MOF-120 is correlated with the presence of OMSs. Compared with the...
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The Influence of Nanometals, Dispersed in the Electrophoretic Nanohydroxyapatite Coatings on the Ti13Zr13Nb Alloy, on Their Morphology and Mechanical Properties
PublicationIn this work, nanohydroxyapatite coatings with nanosilver and nanocopper have been fabricated and studied. The presented results concern coatings with a chemical composition that has never been proposed before. The present research aims to characterize the effects of nanosilver and nanocopper, dispersed in nanohydroxyapatite coatings and deposited on a new, non-toxic Ti13Zr13Nb alloy, on the physical and mechanical properties of...
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99mTc-Galacto-RGD2: A Novel 99mTc-Labeled Cyclic RGD Peptide Dimer Useful for Tumor Imaging
PublicationThis study sought to evaluate [99mTc(HYNIC-Galacto-RGD2)-(tricine)(TPPTS)] (99mTc-Galacto-RGD2: HYNIC = 6-hydrazinonicotinyl; Galacto-RGD2 = Glu[cyclo[Arg-Gly-Asp-D-Phe-Lys(SAA-PEG2-(1,2,3-triazole)-1-yl-4-ethylamide)]]2 (SAA = 7-amino-L-glycero-L-galacto-2,6-anhydro-7-eoxyheptanamide, and PEG2 = 3,6-dioxaoctanoic acid); and TPPTS = trisodium triphenylphosphine-3,3',3''-trisulfonate) as a new radiotracer for tumor imaging. Galacto-RGD2...
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Local properties of organic coatings close to glass transition temperature
PublicationAcrylic coating applied on copper substrate has been investigated at different temperatures starting from the ambient one up to the level above the glass transition temperature. Its local topographic and electric properties have been examined with the atomic force microscopy (AFM) based approach including dc current mapping and local impedance spectroscopy. The local findings have been compared with the information from global...
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Aspects of pollution in Gdansk and gdynia Harbours at the coastal zone of the South Baltic Sea
PublicationOrganotin compounds (OTC), as well as metals, are toxic to many organisms. Even at very low concentrations OTC and metals can have several negative effects. The paper discusses key issues relating to the location of harbours in the coastal zone (including near the river mouths and semi-closed access to the sea) and the pollution of harbour sediments with heavy metals (e.g. zinc, copper, nickel and lead) and organotin derivatives...
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A New Approach for the Mitigating of Flow Maldistribution in Parallel Microchannel Heat Sink
PublicationThe problem of flow maldistribution is very critical in microchannel heat sinks (MCHS). It induces temperature nonuniformity, which may ultimately lead to the breakdown of associated system. In the present communication, a novel approach for the mitigation of flow maldistribution problem in parallel MCHS has been proposed using variable width microchannels. Numerical simulation of copper made parallel MCHS consisting of 25 channels...
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Performance Evaluation of a 650V E-HEMT GaN Power Switch
PublicationGaN power switches have better characteristics compared to the state-of-the-art Si power transistors. These devices offer high operating temperature and current densities, fast switching and low on-resistance. However, currently only a few producers offer technology of high voltage GaN transistors. Immaturity of this technology is the reason why experimental evaluation of GaN parameters must be performed to properly exploit their...
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Honey as an indicator of heavy metals in the environment
PublicationHoney bees collect nectar, pollen and honeydew to produce bee products. One of them is honey, which due to chemical composition and properties is considered by human as a valuable food product. When honey bees collect substrates to produce honey they can bring contaminants to the hive. The presence of xenobiotics in bee products may lower their quality and devalue their properties, and also endanger human health. Many scientists...
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Defective TiO2 Core-Shell Magnetic Photocatalyst Modified with Plasmonic Nanoparticles for Visible Light-Induced Photocatalytic Activity
PublicationIn the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation...
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Design of a Cellular Dual-Band Sticker Antenna for Thickness-Independent 3D-Printed Substrates
PublicationAdditive manufacturing technology provides high flexibility in designing custom enclosures for prototype devices such as nodes of distributed sensor networks. Although integration of components is desired from the perspective of sensor mobility, it might negatively affect the performance of radio-connectivity due to couplings between the antenna and system peripherals, as well as other unaccounted effects of the 3D printed enclosure....
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Projektowanie, synteza i charakterystyka fotokatalizatorów nowej generacji na bazie związku Ti3C2Tx do usuwania aktywnych substancji farmaceutycznych
PublicationCelem niniejszej pracy było zastosowanie materiałów nowej generacji na bazie związku Ti3C2Tx w procesach fotokatalitycznej degradacji aktywnych substancji farmaceutycznych: karbamazepiny, acetaminofenu i ibuprofenu. Zakres prac badawczych obejmował syntezę fotokatalizatorów, charakterystykę ich właściwości fizykochemicznych, oraz ocenę aktywności fotokatalitycznej. Przedstawiono możliwość zastosowania węglika tytanu jako kokatalizatora...
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Qualification of brazing procedure for furnace brazing of austenitic steel according to requirements of the ASME BPVC section IX
PublicationThe article presents the procedure for qualifying brazing technology in a vacuum furnace on the example of stainless steel elements joined with copper filler material from the F-No group. 105, in accordance with the ASME Sec. IX, part QB (ASME Boiler and Pressure Vessel Code. Qualification Standard for Welding, Brazing and Fusing; Procedures; Welders; Brazers; and Welding, Brazing and Fusing Operators). The essential variables...
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Biological and antibacterial properties of chitosan-based coatings with AgNPs and CuNPs obtained on oxidized Ti13Zr13Nb titanium alloy
PublicationDespite numerous studies, the antibacterial efficiency and cytotoxicity of chitosan-based coatings with nanometals need further studies. The purpose of this research was to determine the biological properties of chitosan coatings implemented with either silver nanoparticles (AgNPs) or copper nanoparticles (CuNPs), that were electrophoretically deposited on electrochemically oxidized Ti13Zr13Nb alloy. The SEM tests were used to...
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Cu supported on various oxides as a candidate catalyst for dry methane reforming in DIR-SOFCs systems
PublicationA series of Cu-support systems were tested as potential candidates for DIR-SOFC (Direct Internal Reforming SOFC) catalysts towards a dry reforming of methane (DRM). The various supports (-Al2O3, CeO2, ZrO2, SrTiO3) with comparable specific surface area (SSA), and additionally -Al2O3 with SSA an order of magnitude larger than that of the other supports has been applied. The obtained Cu-support systems were characterized in terms...
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A Low-Profile 3-D Printable Metastructure for Performance Improvement of Aperture Antennas
PublicationIn order to increase the radiation performance of aperture-type antennas, this paper demonstrates a low-profile, planar, single-layer, three-dimensional (3-D) printable metastructure. The proposed hybridized metastructure is highly transparent as it is made out of novel hybrid meta-atoms having transmission coefficient magnitudes greater than -0.72 dB and fully complies with the near-field phase transformation principle. The hybridized...
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Synthesis of 5-Substituted 1H-Tetrazoles from Nitriles in the Presence of Heterogeneous Catalyst
PublicationTetrazoles are five-membered heterocyclic compounds containing in their rings four nitrogen atoms. They have wide applications as corrosion inhibitors, analytical reagents, high-energy materials and gas generating compositions. Tetrazoles also play important role in coordination chemistry as ligands and in medicinal chemistry as metabolically stable surrogates for carboxylic acids. In recent years, investigation of new method of...
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Magneto-thermal convection of low concentration nanofluids
PublicationThe main aim of this paper was to analyze possible utilization of the low concentration nanofluids and the magnetic field to enhance heat transfer. The studied fluids were based on water with an addition of copper particles (40-60 nm diameter). They belonged to the diamagnetic group of materials. As a first attempt to stated target the analysis of enclosure placed in the maximal value of square magnetic induction gradient was carried...
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TiO2-based magnetic nanocomposites with core-shell structure
PublicationThe main aim of the doctoral dissertation was preparation and characterization of photocatalysts, with particular emphasis on modified titanium (IV) oxide photocatalysts, which can be applied for the degradation of organic pollutants not susceptible to biodegradation. A particularly important aspect of the work was the development of preparation method of nanocomposites with the magnetic core-shell and photocatalyst shell (TiO2)...
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Evaluating the influence of radiative heat flux on convective heat transfer from a vertical plate in air using an improved heating plate
PublicationThis article examines the influence of radiative heat flux on the accuracy of the results of free convective heat transfer in air. In order to carry out these tests, based on the experience gained during the operation of a plate heated on one side, compensated by a reverse heat loss flux counter-heater, a unique double-sided heating sandwich plate was designed and built, consisting of three thin epoxy resin plates reinforced with...
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Young shoots of red cabbage are a better source of selected nutrients and glucosinolates in comparison to the vegetable at full maturity
PublicationCruciferous vegetables are a valuable source of ingredients with health benefits. The most characteristic compounds of cruciferous vegetables with identified anticancer properties are glucosinolates. Young shoots and sprouts of red cabbage are becoming a popular fresh food rich in nutrients and bioactive compounds. The objective of this research was to determine, for the first time in a comprehensive approach, whether young shoots...
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Loss Minimization-Based Sensorless Control of High-Speed Induction Motor Considering Core Loss
PublicationThis paper presents loss-minimizing sensorless control (LMC) strategies utilized to optimize the energy of high-speed induction motor (HSIM) drives. A machine’s ability to operate effectively depends on the estimation of its electrical losses. Although copper losses account for the majority of electrical losses in electrical machines, core loss also contributes a major part, particularly in high-speed induction motors. A review...
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Depth chemical profile in a CeIr3 sample
Open Research DataThe polycrystalline sample of CeIr3 used in the present studies was synthesized by arc-melting cerium (4N) and iridium (3N5) in an arc furnace on a water-cooled copper hearth using a tungsten electrode under a high purity argon atmosphere. A piece of zirconium was used as an oxygen getter. First, a button of Ir was prepared by arc-melting the iridium...
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Opracowanie dogodnej metody tworzenia wiązań S-C o hybrydyzacji atomu węgla sp oraz sp2
PublicationBadania przeprowadzone w Katedrze Chemii Organicznej Wydziału Chemicznego Politechniki Gdańskiej na przestrzeni ostatnich kilku lat, pokazały wszechstronność pochodnych kwasu neopentylidenofosforoditiowego. Dotychczasowe wyniki badań doprowadziły mnie do opracowania nowych strategii syntetycznych, umożliwiających otrzymywanie związków zawierających wiązanie C-S o hybrydyzacji atomu węgla sp oraz sp2. Analizując wyniki badań opracowałam...