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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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Exhaled breath gas sensing using pristine and functionalized WO3 nanowire sensors enhanced by UV-light irradiation
PublicationThe development of advanced metal-oxide-semiconductor sensing technologies for the detection of Volatile Organic Compounds (VOCs) present in exhaled breath is of great importance for non-invasive, cheap and fast medical diagnostics. Our experimental studies investigate the effects of operating temperature selection and UV-light irradiation on improving the response of WO3 nanowire sensors towards exhaled breath exposure. Herein,...
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Mono- and bi-metallic plasmonic photocatalysts for degradation of organic compounds under UV and visible light irradiation
PublicationTitania powders were surface modified with gold and/or silver nanoparticles (NPs) by photodeposition method. Gold modified titania exhibited much higher photocatalytic activity during methanol dehydrogenation under UV irradiation than titania modified with monometallic silver and bimetallic Au–Ag NPs. Bimetallic photocatalysts exhibited either enhanced or reduced visible light activity, depending on properties of noble metal NPs,...
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Performance Assessment of Using Docker for Selected MPI Applications in a Parallel Environment Based on Commodity Hardware
PublicationIn the paper, we perform detailed performance analysis of three parallel MPI applications run in a parallel environment based on commodity hardware, using Docker and bare-metal configurations. The testbed applications are representative of the most typical parallel processing paradigms: master–slave, geometric Single Program Multiple Data (SPMD) as well as divide-and-conquer and feature characteristic computational and communication...
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Mechanical, Thermal and Rheological Properties of Polyethylene-Based Composites Filled with Micrometric Aluminum Powder
PublicationInvestigations related to polymer/metal composites are often limited to the analysis of the electrical and thermal conductivity of the materials. The presented study aims to analyze the impact of aluminum (Al) filler content (from 1 to 20 wt%) on the rarely investigated properties of composites based on the high-density polyethylene (HDPE) matrix. The crystalline structure, rheological (melt flow index and oscillatory rheometry),...
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Laser Beam as a Precision Tool to Increase Fatigue Resistance in an Eyelet of Undercarriage Drag Strut
PublicationThe article contains the results of tests on a laser-processed eyelet of undercarriage drag strut to increase its fatigue strength. Laser processing concentrated on both sides around the hole of eye for connecting the undercarriage drag strut caused that the material in this area withstood more than twice the number of load cycles established for this material. In order to determine the reasons for the increase in fatigue strength,...
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Pasywacja stali nierdzewnych
PublicationOdporność chemiczna stali odpornych na korozję oparta jest calkowicie na pasywnym charakterze warstw powierzchniowych istniejących na tych stalach. Pasywność to stan, w którym metal aktywny wykazuje podwyższoną odporność korozyjną dzięki tworzeniu na powierzchni warstewki, która jest stabilna w danym środowisku, pH i potencjale oraz stanowi produkt korozji.
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The Quality of the Outflow from Conventional WWTPs and Treatment Wetlands
PublicationUntil recently the humic substances were considered to have no negative impact on human health. Therefore elimination of these substances from potable water was only performed due to aesthetic reasons. In the recent years, however, it was found out that humic substances may cause unacceptable smell of water or cumulate toxic substances by complexing metal ions and adsorption of persistent organic pollutants such as pesticides,...
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New nanoadsorbent based on magnetic iron oxide containing 1,4,7,10-tetraazacyclododecane in outer chain (Fe3O4@SiO2-cyclen) for adsorption and removal of selected heavy metal ions Cd2+, Pb2+, Cu2+
PublicationMagnetic Fe3O4@SiO2-cyclen nanoparticles were prepared and used as adsorbent for Cd2+, Pb2+ and Cu2+ from aqueous solution removal process controlled with differential pulse anodic stripping voltammetry (DPASV) and hanging mercury drop electrode (HDME). Nanomaterial was synthesised in three-step process co-precipitation of Fe3O4 core, coating with silane and N-(3-(triethoxysilyl)propyl)-1,4,7,10-tetraazacyclododecane-1-carboxamide...
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Multipath Complex Root Tracing
PublicationThe problem of multipath root tracing is being addressed in this communication. The self-adaptive complex root tracing algorithm, which was previously utilized for the investigation of various propagation and radiation problems, is analyzed here for the cases when the traced characteristic bifurcates. A procedure of multiroute detection is proposed and demonstrated on the coaxially loaded cylindrical waveguide example.
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Properties and interpretation of Instantaneous Complex Frequency
PublicationThe concept of Instantaneous Complex Frequency (ICF) was first defined by Lindon and developed mainly in works of two authors S. Hahn and M. Rojewski. Although it is not widely used in signal analysis, ICF was already used as a complex signal representation in the verification of handwritten signatures, pitch estimation, symbol timing recovery in PSK receiver and in detection of anomalies in data transmission. It should be noted,...
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Towards Robust Identification of Nonstationary Systems
PublicationThe article proposes a fast, two-stage method for the identification of nonstationary systems. The method uses iterative reweighting to robustify the identification process against the outliers in the measurement noise and against the numerical errors that may occur at the first stage of identification. We also propose an adaptive algorithm to optimize the values of the hyperparameters that are crucial for this new method.
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High-Temperature Tensile Behaviour of GTAW Joints of P92 Steel and Alloy 617 for Two Different Fillers
PublicationThis study explores the high-temperature (HT) tensile rupture characteristics of a dissimilar gas-tungsten-arc-welded (GTAW) joint between P92 steel and Alloy 617, fabricated using ER62SB9 and ERNiCrCoMo-1 fillers. The high-temperature tensile tests were performed at elevated temperatures of 550 ◦C and 650 ◦C. An optical microscope (OM) and a field emission scanning electron microscope (FESEM) were utilized to characterize the...
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NOx Photooxidation over Different Noble Metals Modified TiO2
PublicationWe compared the activity enhancement effect of noble metal deposited on TiO2 in photocatalytic nitrogen oxides oxidation. Titanium dioxide was decorated with Ag, Au, Pt or Pd in the sol-gel process. Synthesized catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller measurement (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX)....
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Is the Solid Electrolyte Interphase an Extra-Charge Reservoir in Li-Ion Batteries?
PublicationAdvanced metal oxide electrodes in Li-ion batteries usually show reversible capacities exceeding the theoretically expected ones. Despite many studies and tentative interpretations, the origin of this extra-capacity is not assessed yet. Lithium storage can be increased through different chemical processes developing in the electrodes during charging cycles. The solid electrolyte interface (SEI), formed already during the first...
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Submicron inorganic particles as an additional filler in hybrid epoxy matrix composites reinforced with glass fibres
PublicationIn this study, the effect of selected submicron metal oxide (zinc oxide, titanium oxide) or non-metal oxide (silicon dioxide) particles on mechanical and thermo-mechanical properties of epoxy/glass composites was investigated. The applied epoxy resin was a diglycidyl ether of bisphenol-A cured with triethylenetetramine. As a reinforcement twill weave E-glass fabric was used. Hybrid composites (contained particulate and fibrous...
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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Exploring Neural Networks for Musical Instrument Identification in Polyphonic Audio
PublicationThe purpose of this paper is to introduce neural network-based methods that surpass state-of-the-art (SOTA) models, either by training faster or having simpler architecture, while maintaining comparable effectiveness in musical instrument identification in polyphonic music. Several approaches are presented, including two authors’ proposals, i.e., spiking neural networks (SNN) and a modular deep learning model named FMCNN (Fully...
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Mathematical modeling and prediction of pit to crack transition under cyclic thermal load using artificial neural network
PublicationThe formation of pitting is a major problem in most metals, which is caused by extremely localized corrosion that creates small holes in metal and subsequently, it changes into cracks under mechanical load, thermo-mechanical stress, and corrosion process factors. This research aims to study pit to crack transition phenomenon of steel boiler heat tubes under cyclic thermal load, and mathematical modeling...
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Glucosamine-6-phosphate synthase with an oligoHis insert
PublicationGlucosamine-6-phosphate (GlcN-6-P) synthase known also as L-Glutamine: D-fructose-6-phosphate aminotransferase (EC 2.6.1.16), catalyzes the first committed step in the amino sugar biosynthetic pathway in prokaryotic and eukaryotic organisms. The final product of this pathway is an activated precursor of numerous macromolecules containing amino sugars, including chitin and mannproteins in fungi, peptydoglican and lipopolysaccharides...
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Ruthenium(II) and Iridium(III) Complexes as Tested Materials for New Anticancer Agents
PublicationThe oncological use of cisplatin is hindered by its severe side eects and a very important resistance problem. To overcome these problems, scientists have attempted to design new generation transition-metal anticancer complexes. In this study, we present new complexes, ruthenium(II) [(6-p-cymene)RuCl(py2CO)]PF6 (1), iridium(III) [(5-Cp)IrCl(py2CO)]PF6 (2), and NH4[IrCl4(py2CO)]H2O (3), based on di-2-pyridylketone (py2CO). The prepared...
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Conducting polymer films for biodegradable metallic cardiovascular stents
PublicationIn recent years, there is increasing interest to create biodegradable metallic cardiovascular stents instead of using their permanent form. The most interesting materials for this purpose are iron and its alloys. However, in order to use it in clinical application, their degradation rate and biological performance need to be optimized. One promising solution is coating the metal with conducting polymer films. In this work, short...
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The effect of calcination temperature on structure and photocatalytic properties of Au/Pd nanoparticles supported on TiO2
PublicationBimetallic nanoparticles, composed of two different metal elements, can exhibit peculiar electronic, optical, and catalytic or photocatalytic properties that are absent in the corresponding monometallic nanoparticles. We show the effect of calcination temperature (from 350 to 700°C) on the structure and the photocatalytic properties of Au/Pd-modified TiO2. The composition of the bimetallic Au/Pd nanoparticles in relation to their...
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MXene-based composites for capacitive deionization – The advantages, progress, and their role in desalination - A review
PublicationMXenes, a novel large family of 2D transition metal carbides, carbonitrides and nitrides are currently a “hot topic” in science due to their several fascinating physical and chemical properties. It follows from a rich diversity of their elemental compositions and chemical functionalities. MXenes can form composites with many substances, including polymers or metal oxides, which allows to effective “tune” MXene characteristics to...
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A palatal prosthesis from archaeological research in the St Francis of Assisi church in Cracow (Poland)
PublicationThe hard palate is a septum that not only prevents food from entering between the oral and nasal cavity, but also plays an important role during breathing or speech. The presence of cavities within it negatively affects the comfort of life of people with this type of impairment. Hence, in the literature one can find examples of the use of hard palate prostheses to restore the separation between the nasal and oral cavity. During...
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Powering the Future by Iron Sulfide Type Material (FexSy) Based Electrochemical Materials for Water Splitting and Energy Storage Applications: A Review
PublicationWater electrolysis is among the recent alternatives for generating clean fuels (hydrogen). It is an efficient way to produce pure hydrogen at a rapid pace with no unwanted by-products. Effective and cheap water-splitting electrocatalysts with enhanced activity, specificity, and stability are currently widely studied. In this regard, noble metal-free transition metal-based catalysts are of high interest. Iron sulfide (FeS) is one...
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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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Study on Microstructural Characterization, Mechanical Properties and Residual Stress of GTAW Dissimilar Joints of P91 and P22 Steels
PublicationThis article deals with the dissimilar joining of two different grade Cr-Mo steel (2.25Cr-1Mo: P22 and modified 9Cr-1Mo: P91) for power plant application. The dissimilar butt-welded joint was produced for conventional V groove design by using the gas tungsten arc welding (GTAW) process with the application of an ERNiCrMo-3 Ni-based super alloy filler. A microstructure characterization was performed to measure the inhomogeneity...
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Determining the leakage current resistive component by the orthogonal vector method
PublicationThe measurement of the metal – oxide surge arresters (MOSA) leakage current and the analysis of its components is a key diagnostic criterion according to technical standards. During on site MOSA condition assessment, the easy way is based on the measurement only leakage current, without the inconvenient live working measurements of supply voltage. Orthogonal vectors method of determination the resistive leakage current is presented....
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THE USE OF THE Ti-13Zr-13Nb ALLOY POWDER FOR MANUFACTURING OF PROSTHETIC PARTS BY SELECTIVE LASER MELTING
PublicationThe 3D printing is a manufacturing technique belonging to the additive methods able to prepare the designed parts for various purposes. The present reasearch was aimed to fabricate the prosthetic foundations and bridges made of the new Ti-13Zr-13Nb alloy by the selective laser melting (SLM) of a metal powder. The scanning electron examinations and micro scanning tomography were used to investigate the surface quality and intrinsic...
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Azo and azoxythiacrown ethers: synthesis and properties
PublicationA series of 16- and 18-membered azo- and azoxythiacrown ethers have been synthesized by reductive macrocyclization of the respective bis(nitrophenoxy)oxaalkanes. The aromatic residues located in the polyether region of the molecule were introduced to macrocyclic skeletons and their affinities toward different groups of metal cations in ion-selective electrodes were described. X-ray structures for one dinitropodand and one azoxybenzothiacrown...
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Instantaneous complex frequency for pipeline pitch estimation
PublicationIn the paper a pipeline algorithm for estimating the pitch of speech signal is proposed. The algorithm uses instantaneous complex frequencies estimated for four waveforms obtained by filtering the original speech signal through four bandpass complex Hilbert filters. The imaginary parts of ICFs from each channel give four candidates for pitch estimates. The decision regarding the final estimate is made based on the real parts of...
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Inhibition of impurities formation in the synthesis of N-alkyltheobromines stimulated by microwave irradiation. Cationic and anionic response of membrane electrodes
PublicationN-Alkyltheobromine (1-9) derivatives were obtained by reacting theobromine with appropriate alkyl halide under microwave irradiation at 100-150 W and by conventional synthesis. Formation of by-products of oxygen atom alkylation and 1-N-alkyltheobromine ring opening were considered. The presented compounds 1-5 have been studied as ion carriers in ion-selective membrane electrodes. Selectivity of these membranes was studied towards...
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The Effect of Welding Conditions on Mechanical Properties of Superduplex Stainless Steel Welded Joints
PublicationThe tests results of superduplex stainless steel welded joints made with a different heat input, using automatic submerged arc welding (SAW) and semi-automatic flux-cored arc welding (FCAW) have been presented. Metallographic examinations, the measurements of the ferrite content, the width of the heat affected zone (HAZ) and the hardness of the welds in characteristic areas have been performed. Significant differences in the amount of...
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Novel Biomass-Based Polymers: Synthesis, Characterization, and Application
PublicationA wide range of polymers were prepared from biomass-derivatives, using different polymerization mechanisms. Well-defined, fully hydroxy-functional polyesters based on aliphatic diols were synthesized, using either conventional metal-based catalysts or the organic superbase 1,5,7-triazabicyclododecene (TBD). Unsaturated polyesters were also made, offering additional functionality to these biobased resins. Metal-catalyzed or enzymatic...
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X-Ray Computer Tomography Study of Degradation of the Zircaloy-2 Tubes Oxidized at High Temperatures
PublicationThe investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube...
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Ionic liquids for nano- and microstructures preparation. Part 1: Properties and multifunctional role
PublicationIonic liquids (ILs) are a broad group of organic salts of varying structure and properties, used in energy conversion and storage, chemical analysis, separation processes, as well as in the preparation of particles in nano- and microscale. In material engineering, ionic liquids are applied to synthesize mainly metal nanoparticles and 3D semiconductor microparticles. They could generally serve as a structuring agent or as a reaction...
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Ongoing progress on novel nanocomposite membranes for the separation of heavy metals from contaminated water
PublicationMembranes, as the primary separation element of membrane-based processes, have greatly attracted the attention of researchers in several water treatment applications, including wastewater treatment, water purification, water disinfection, toxic and non-toxic chemical molecules, heavy metals, among others. Today, the removal of heavy metals from water has become challenging, in which chemical engineers are approaching new materials...
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MOF/TiO2 erythrocyte-like heterostructures decorated by noble metals for use in hydrogen photogeneration and pollutant photodegradation
PublicationVarious metal–organic framework (MOF)/TiO2 heterostructures can be obtained by the partial hydrolysis or calcination of Ti-based MOFs. By adjusting the hydrolysis and calcination steps of NH2-MIL-125 (Ti), a novel photoactive material composed of a MOF (NH2-MIL-125 (Ti)) and TiO2, with a unique “erythrocyte” shape, was developed. Furthermore, modification of the composition prepared by the partial hydrolysis of NH2- MIL-125 (Ti)...
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A new strategy for PET depolymerization: Application of bimetallic MOF-74 as a selective catalyst
PublicationLarge-volume production of poly(ethylene terephthalate) (PET), especially in the form of bottles and food packaging containers, causes problems with polymer waste management. Waste PET could be recycled thermally, mechanically or chemically and the last method allows to obtain individual monomers, but most often it is carried out in the presence of homogeneous catalysts, that are difficult to separate and reuse. In view of this,...
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Monitoring Lead Concentration in the Surrounding Environmental Components of a Lead Battery Company: Plants, Air and Effluents—Case Study, Kenya
PublicationLead (Pb) pollution from smelters and lead–acid battery has become a serious problem worldwide owing to its toxic nature as a heavy metal. Stricter regulations and monitoring strategies have been formulated, legislated and implemented in various parts of the world on heavy metal usage. Developed countries such as the USA and in Europe largely operate within the set standards, however, developing countries such as Kenya, Nigeria...
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Study of the anticancer potential of Cd complexes of selenazoyl-hydrazones and their sulfur isosters
PublicationThe biological activity of Cd compounds has been investigated scarce since Cd has been recognized as a human carcinogen. However, the toxicity of cadmium is comparable to the toxicity of noble metals such as Pt and Pd. The paradigm of metal toxicity has been challenged suggesting that metal toxicity is not a constant property, yet it depends on many factors like the presence of appropriate ligands. Studies on anticancer activity...
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Electrical Transport and Magnetic Properties of Metal/Metal Oxide/Metal Junctions Based on Anodized Metal Oxides
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Electrical Transport and Magnetic Properties of Metal/Metal Oxide/Metal Junctions Based on Anodized Metal Oxides
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On noncausal identification of nonstationary stochastic systems
PublicationIn this paper we consider the problem of noncausal identification of nonstationary,linear stochastic systems, i.e., identification based on prerecorded input/output data. We show how several competing weighted least squares parameter smoothers, differing in memory settings, can be combined together to yield a better and more reliable smoothing algorithm. The resulting parallel estimation scheme automatically adjusts its smoothing...
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Wpływ wybranych właściwości maszyny badawczej na wynik eksperymentu tribologicznego z tarciem ślizgowym
PublicationNiniejsza monografia stanowi podsumowanie przekrojowych badań związanych z wpływem właściwości stanowiska badawczego (tribometru) na przebieg i rejestrowane wyniki eksperymentu tribologicznego z tarciem ślizgowym ciał stałych smarowanych cieczą w warunkach tarcia bez efektów smarowania hydrodynamicznego. Autor przedstawia wyniki kompleksowych analiz właściwości dynamicznych stanowiska badawczego w kontekście efektów obserwowanych...
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Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
PublicationDerivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally...
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THE EFFECT OF WET UNDERWATER WELDING ON COLD CRACKING SUSCEPTIBILITY OF DUPLEX STAINLESS STEEL
PublicationABSTRACT The present work was conducted to assess the weldability of duplex stainless steel in underwater conditions. Metal manual arc welding (MMA) with the use of coated electrodes was used in the investigations. Tekken weldability tests were performed underwater at 0.5 m depth and in the air. Nondestructive tests, metallographic examinations of welds, ferrite content assessment in microstructure and hardness test were performed....
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Underwater Local Cavity Welding of S460N Steel
PublicationIn this paper, a comparison of the mechanical properties of high-strength low-alloy S460Nsteel welded joints is presented. The welded joints were made by the gas metal arc welding (GMAW)process in the air environment and water, by the local cavity welding method. Welded joints were testedfollowing the EN ISO 15614-1:2017 standard. After welding, the non-destructive—visual, penetrant,radiographic, and ultrasonic (phased array) tests...
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Catalytic Activity of Nickel and Ruthenium–Nickel Catalysts Supported on SiO2, ZrO2, Al2O3, and MgAl2O4 in a Dry Reforming Process
PublicationDry reforming of methane (DRM) is an eco-friendly method of syngas production due to the utilization of two main greenhouse gases—methane and carbon dioxide. An industrial application of methane dry reforming requires the use of a catalyst with high activity, stability over a long time, and the ability to catalyze a reaction, leading to the needed a hydrogen/carbon monoxide ratio. Thus, the aim of the study was to investigate the...