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Search results for: sample preparation
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Novel and Efficient Synthesis of Unsymmetrical Trisulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical trisulfides under mild conditions in very good yields. The designed method is based on the straightforward preparation of 1-[(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl)trisulfanyl]dodecane from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane, sulfur dichloride (SCl2) and dodecane-1-thiol. The unsymmetrical trisulfides can...
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Exergetic Analysis of the nCO2PP Cycle with Particular Reference to the Exergy Destruction of Sewage Sludge Due to Gasification
PublicationAn exergy analysis is carried out on the negative CO2 emission gas power plant (nCO2PP), which integrates the process sections of fuel preparation, power generation and carbon capture. Processes of exergy destruction are studied with particular focus on the process in the gasification unit of the fuel preparation section, where a large amount of exergy is destroyed in various chemical reactions from sewage sludge to producer gas...
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Lessons learned during SRAD hybrid motor development
PublicationStudent Researched and Developed (SRAD) hybrid rocket motor H-15 with total impulse of 15 $kNs$ was built. First version of the engine has average thrust of 3 $kN$, the second, improved one is prepared with an aim to have average thrust of 5 $kN$. Engine development was started from scratch and went through phases of: definition of design assumptions and constraints, numerical modelling to predict engine performance, CAD and CAM...
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Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes
PublicationDeep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes...
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Toward Polyethylene–Polyester Block and Graft Copolymers with Tunable Polarity
PublicationThe synthesis and characterization of polyethylene–polyester block and graft copolymers and their potential as compatibilizers in polyethylene-based polymer blends are being described. The various routes to functionalized polyethylenes and the corresponding block/graft copolymers have been compared and evaluated for their scalability to industrial scale production. Hydroxyl chain-end and randomly OH-functionalized HDPE as well...
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Novel and Efficient Methods for the Synthesis of Symmetrical Trisulfides
PublicationWe have developed a convenient methods for the synthesis of symmetrical trisulfides under mild conditions in very good yields. The described methods are based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-disulfanyl derivatives from readily available 5,5-dimethyl-2-sulfanyl-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The symmetrical...
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Experimental test of nonclassicality with arbitrarily low detection efficiency
PublicationWe theoretically introduce and experimentally demonstrate the realization of a nonclassicality test that allows for arbitrarily low detection efficiency without invoking an extra assumption of independence of the devices. Our test and its implementation is set in a prepare-and-measure scenario with an upper limit on the classical communication capacity of the channel through which the systems are communicated. The essence for our...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Styrene Oxidation by Copper(II) Complexes Salen-Type Encapsulated into Nay Zeolite
PublicationThe copper(II) complex with a Schiff-base salen-type ligand has been encapsulated in the nanopores of a NaY zeolite by using two different methodologies, the flexible ligand and in situ complex preparation methods. The encapsulated and non-encapsulated copper(II) complexes were screened as catalysts for styrene oxidation by using TBHP as the oxygen source in acetonitrile solvent. Under the optimized conditions, the catalysts exhibited...
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CDIO IN GDANSK: PEOPLE-ORIENTED STRATEGY
PublicationThe CDIO system implementation in Poland meets problems and Gdansk University of Technology (GUT) is still a single higher education institution in Poland accepted as the member of CDIO Initiative. The paper detects and characterizes the existing problems to be solved. In particular, the different groups of people are considered as supporters or fighters against CDIO idea, their attitudes being considered and applied strategy demonstrated. The...
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Deep eutectic solvents microbial toxicity: Current state of art and critical evaluation of testing methods
PublicationDeep eutectic solvents (DESs) were described at the beginning of 21st century and they consist of a mixture of two or more solid components, which gives rise to a lower melting point compared to the starting materials. Over the years, DESs have proved to be a promising alternative to traditional organic solvents and ionic liquids (ILs) due to their low volatility, low inflammability, easy preparation, and usually low cost of compounds...
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Novel ABTS-dot-blot method for the assessment of antioxidant properties of food packaging
PublicationThe new ABTS-dot-blot method for the direct determination of antioxidant activity of active packaging that is in contact with foodstuffs has been developed. The usefulness of the new method was verified with the use of agarose, pork gelatin, bacterial cellulose and cellulose-chitosan films with incorporated standard antioxidant – Trolox or plant phytochemicals derived from three types of berry juices (chokeberry, blue-berried honeysuckle,...
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Distinction of clenbuterol intake from drug or contaminated food of animal origin in a controlled administration trial – the potential of enantiomeric separation for doping control analysis
PublicationThe differentiation of clenbuterol abuse and unintentional ingestion by contaminated meat is crucial with respect to the valuation of an adverse analytical finding in human sports doping control. The proportion of the two enantiomers of clenbuterol may serve as potential discriminating parameter. For the determination of the individual enantiomers, specific methods were developed and validated for the different matrices under investigation...
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A versatile and convenient preparation of unsymmetrical diaryl disulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical diaryl disulfides under mild conditions in excellent yields. The described method is based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-sulfenyl bromide from readily available 5,5-dimethyl-2-thiolo-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The unsymmetrical...
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Convenient Synthesis of Functionalized Unsymmetrical Vinyl Disulfides and Their Inverse Electron-Demand Hetero-Diels-Alder Reaction
PublicationThe simple, convenient, and efficient methods for the preparation of unsymmetrical vinyl disulfides with additional functional groups under mild conditions with moderate to high yields were designed. The developed methods include the reaction of S-vinyl phosphorodithioate with thiotosylates or S-vinyl thiotosylate with thiols. The designed methods allow for the synthesis of unsymmetrical vinyl disulfides with additional functionalities...
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Study of the Operation of Synchronous Generator Voltage Regulator During the Creation of Post Blackout Start-up Path
PublicationThis paper presents the influence of automatic voltage regulator (AVR) of synchronous generator on the process of creation of post black-out start-up path. Two elements of AVR have a significant impact on this process: underexcitation limiter (UEL) and load compensation (LC). The authors present a theoretical investigation and simulation results that illustrate how the mentioned elements of AVR affect voltage levels in a power...
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Effects of Xanthan Gum Biopolymer on the Permeability, Odometer, Unconfined Compressive and Triaxial Shear Behavior of a Sand
PublicationBiopolymers, which are microbially induced polymers, can be used as an alternative material to improve engineering performance of soils. In this paper, a laboratory study of 0.075-1.0 mm size sand and biopolymer (i.e., xanthan gum) mixtures with various mix ratios (0%, 0.5%, 1.0%, and 1.5%) was performed. The materials, specimen preparation, and test methods are described, as are the results of a suite of permeability, odometer, unconfined...
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La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ oxygen electrodes for solid oxide cells prepared by polymer precursor and nitrates solution infiltration into gadolinium doped ceria backbone
PublicationInfiltration is a method, which can be applied for the electrode preparation. In this paper oxygen electrode is prepared solely by the infiltration of La0.6Sr0.4Co0.2Fe0.8O3‐δ (LSCF) into Ce0.8Gd0.2O2-δ (CGO) backbone. The use a polymer precursor as an infiltrating medium, instead of an aqueous nitrate salts solution is presented. It is shown that the polymer forms the single-phase perovskite at 600 °C, contrary to the nitrates...
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Biopolymers in designing modern antimicrobial medical materials. Part I. Biopolymer medical materials - collagen, chitosan
PublicationThe article is a review of the literature concerning the possible use of biopolymers for the preparation of dressings with antimicrobial activity. Authors show the potential of biopolymers: collagen and chitosan - which have the ability to immobilize and control the release of various active compounds - for providing the appropriate antibacterial, bacteriostatic and wound healing properties. Types of threats, for which the dressing...
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Emulsifi ers from renewable materials: an eco-friendly synthesis and properties
PublicationThe focus of this study was the preparation of novel bio based polyglycerol emulsifiers characterized by a one pot synthesis, thus by modified properties with respect to interfacial activity and effectiveness as emulsion stabilizers. The final products of the esterification process, carried out in the presence of carboxylates were used directly as emulsifiers (without purification or fractionation). Polyglycerol emulsifiers obtained...
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Analyzing the Geometry of the Turnouts and Their Adjustment Basing on the Tacheometer Measurements
PublicationThe article presents the results of tacheometric measurements of a station throat, as well as the method of data preparation and analysis. The calculations covered the verification of the geometry and the location of railway turnouts and crossings. The analyses were performed for the selected parameters of the turnout geometry, including their lengths and track gauge in main sections. In addition, the data were analyzed to confirm...
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Investigations on mixture preparation for two phase adiabatic pressure drop of R134a flowing in 5 mm diameter channel
PublicationThe article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a. Study cases have been set for a mass flux varying from 200 to 400 kg/m2 s, at the saturation temperature of 19.4 ◦C. Obtained experimental data was compared with the available correlations from the literature for the frictional pressure drop during adiabatic flow. Influence of mixture preparation on pressure drop was investigated, for...
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RECSYS CHALLENGE 2015: a BUY EVENT PREDICTION IN THE E-COMMERCE DOMAIN
PublicationIn this paper we present our approach to RecSys Challenge 2015. Given a set of e-commerce events, the task is to predict whether a user will buy something in the current session and, if yes, which of the item will be bought. We show that the data preparation and enrichment are very important in finding the solution for the challenge and that simple ideas and intuitions could lead to satisfactory results. We also show that simple...
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Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
PublicationDry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as...
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Chitosan-based inks for 3D printing and bioprinting
PublicationThe advent of 3D-printing/additive manufacturing in biomedical engineering field has introduced great potential for the preparation of 3D structures that can mimic native tissues. This technology has accelerated the progress in numerous areas of regenerative medicine, especially led to a big wave of biomimetic functional scaffold developments for tissue engineering demands. In recent years, the introduction of smart bio-inks has...
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Synthesis, structural characterization, and thermal properties of Ca‐ and La‐doped soda‐lime glasses by laser melting
PublicationLaser melting techniques have been used in the preparation of unconventional glass compositions with high melting temperatures. Thus, we wanted to test the feasibility of using a CO2 laser in the preparation of nitrogen-rich oxynitride glasses and nitride silicate glasses. Melting from oxides and metallic raw materials, we wanted to study first glass formation and possible evaporation losses of the glass components. Two glass series...
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Phosphate and Thiophosphate Biphenyl Analogs as Steroid Sulfatase Inhibitors
PublicationIn the present work, we report convenient methods for the synthesis and biological evaluation of phosphate and thiophosphate biphenyl derivatives exhibiting steroid sulfatase (STS) activity. The described synthesis is based on straightforward preparation of biphenyl-4-ol and 40-hydroxybiphenyl- 4-carboxylic acid ethyl ester modified with various phosphate or thiophosphate moieties. The inhibitory effects of these compounds were...
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Analytical eco-scale for assessing the greenness of analytical procedures
PublicationWe propose the analytical eco-scale as a novel comprehensive approach to evaluating the greenness of analytical methodology. It is based on assigning penalty points to parameters of an analytical process that are not in agreement with the ideal green analysis. This approach compares different parameters and different steps of the analytical process. Traditional green chemistry metrics 9e.g. Atom Economy, E-factor and Reaction Mass...
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Experimental certification of an informationally complete quantum measurement in a device-independent protocol
PublicationMinimal informationally complete positive operator-valued measures (MIC-POVMs) are special kinds of measurement in quantum theory in which the statistics of their d2-outcomes are enough to reconstruct any d-dimensional quantum state. For this reason, MIC-POVMs are referred to as standard measurements for quantum information.Here, we report an experiment with entangled photon pairs that certifies, for what we believe is the first...
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Synthesis and Characterization of Monometallic (Ag, Cu) and Bimetallic Ag-Cu Particles for Antibacterial and Antifungal Applications
PublicationIn this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs). We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM) with...
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Flood risk assessment for office and services building Alchemia II at Al. Grunwaldzka 409 in Gdansk.
PublicationThe aim of the study is to assess the risk of flood from natural meteorological and hy-drological phenomena, for office and services building Alchemia II in Gdansk at Al. Grun-waldzka 409. The project includes the analysis of potential sources of floods in Gdansk re-garding the Baltic Sea and the Gulf of Gdansk, the Vistula River basin and excessive rainfall and snowmelt waters being a significant element of hydrological processes...
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Evaluation of the Effectiveness of Methods for Delimitation of the Boundaries of Registered Parcels in the Process of Modernization of Land and Building Registration
PublicationIn the article, a comparative analysis of two methods for delimitation of the boundaries of registered parcels was carried out: the method of direct measurement in the field and the photogrammetric method. One of the analyzed factors was the attendance of parcels’ owners during the development of boundary recognition agreements. Research has shown that in this aspect the method of direct measurement...
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Preparation of bicyclic β-lactam and bicyclic 1,3- oxazinone scaffolds using combined cycloaddition and metathesis processes
PublicationA simple, efficient two-step method for the preparation of heterobicyclic compounds was developed. Starting from 5-acyl or 5-carbamoyl-2,2- dimethyl-1,3-dioxa-4,5-dione bicyclic scaffolds of 1-azabicyclo[5.2.0]non- 3-en-9-one, 6,9,10,10a-tetrahydro-4H-[1,3]oxazino[3,2-a]azepin-4-one, and 6,9,10,10a-tetrahydro-2H-[1,3]oxazino[3,2-a]azepine-2,4(3H)-dione were prepared using cycloaddition of thermally generated ketenes to aldimines...
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Simple colorimetric copper(II) sensor – spectral characterization and possible applications
PublicationNew o-hydroxyazocompound L bearing pyrrole residue was obtained in the simple synthetic protocol. The structure of L was confirmed and analyzed by X-ray diffraction. It was found that new chemosensor can be successfully used as copper(II) selective spectrophotometric regent in solution and can be also applied for the preparation of sensing materials generating selective color signal upon interaction with copper(II). Selective colorimetric...
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Properties of Nasicon-based CO2 sensors with Bi8Nb2O17 reference electrode
PublicationPotentiometric CO2 sensors based on Nasicon (Na+ conductor, Na3Zr2Si2PO12) electrolyte, Bi8Nb2O17/Pt reference electrode and different sensing electrodes have been prepared. Besides the sensing electrode material, sensors differ from each other in the reference electrode preparation technique. The main aim of this study is to investigate sensor construction and electrode fabrication process influence on sensor properties. The optimal...
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Preparation of porous TiO2 films by means of pulsed laser deposition for photocatalytic applications
PublicationIn this work the preparation and structure properties of porous thin films of TiO2 were investigated. The films were produced by means of the pulsed laser deposition technique using laser pulses at 266nm (10Hz) and at fluencies of 1-3.5J/cm2. The process was performed in vacuum using O2 buffer gas and films were deposited on the SiO2 glass or Si substrate. X-ray diffraction (XRD) and Raman analysis of the structure and chemical...
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Structure elucidation of carbamoylo-β-lactam diastereoisomers by ROESY and NOESY experiments
PublicationRecently we have focused in the problem of preparation of carbamoylo-β-lactams as a result of oxidative cyclization of malonyl enamides. In our experiments we obtain mixture of two main β-lactam products: as a result of subsequent elimination and a second as a product of substitution. All of the produced β-lactams have trans configuration what was confirmed by 1H coupling constants. However id should be stressed that in the case...
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Quantum randomness protected against detection loophole attacks
PublicationDevice and semi-device-independent private quantum randomness generators are crucial for applications requiring private randomness. However, they are vulnerable to detection inefficiency attacks and this limits severely their usage for practical purposes. Here, we present a method for protecting semi-device-independent private quantum randomness generators in prepare-and-measure scenarios against detection inefficiency attacks....
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Evaluation of Praseodymium and Gadolinium Doped Ceria as a Possible Barrier Layer Material for Solid Oxide Cells
PublicationIn this work, nanocrystalline layers based on the Pr, Gd co-doped CeO2 were investigated. For the preparation of thin layers, lowtemperature spray pyrolysis technique was used. Different stoichiometries of the layers were produced for comparison on polished sapphire substrates. The microstructure of the prepared thin layers was studied by scanning electron microscopy (SEM), energydispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD)....
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Developing Novel Solutions to Realise the European Energy - Information Sharing & Analysis Centre
PublicationFor more effective decision making in preparation for and response to cyberevents in the energy sector, multilevel situation awareness, from technical to strategic is essential. With an uncertain picture of evolving threats, sharing of the latest cybersecurity knowledge among all sector stakeholders can inform and improve decisions and responses. This paper describes two novel solutions proposed during the formation of the European...
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Employment of University Graduates in the Era of Digitalization and Artificial Intelligence: Challenges and Prospects
PublicationDigital technologies are profoundly reshaping the labor market, causing structural shifts in the economy and altering the nature of work. These changes have significant implications for youth employment, exacerbating the issue of unemployment. This paper delves into the importance of graduate employment in contemporary society, with a particular focus on the influence of digital technologies and Artificial Intelligence. The authors...
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Bio‑derived polyurethanes obtained by non‑isocyanate route using polyol‑based bis(cyclic carbonate)s—studies on thermal decomposition behavior
PublicationNon-isocyanate polyurethanes (NIPUs) constitute one of the most prospective groups of eco-friendly materials based on their phosgene-free synthesis pathway. Moreover, one of the steps of their obtaining includes the use of carbon dioxide (CO 2 ), which allows for the promotion of the development of carbon dioxide capture and storage technologies. In this work, non- isocyanate polyurethanes were obtained via three-step synthesis...
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Superhydrophobic and superoleophilic melamine sponges impregnated with deep eutectic solvents for oil spill cleanup
PublicationThe extensive extraction of oil from the bottom of seas and oceans and its transportation by tankers increase the risk of potential environmental disasters associated with hydrocarbon fractions entering water reservoirs. Therefore, this paper presents the preparation of a simple impregnation of a melamine sponge with deep eutectic solvents (DES), which can be obtained from natural sources, including coconut oil, palm kernel oil,...
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Quality assessment of ZnO-based varistors by 1/f noise
PublicationNoise has been used as a diagnostic tool of surge arrester varistor structures comprising of ZnO grains of various type and size. The physical and electrical properties of the measured samples have been described. In the experimental study, the applied measurement system and the results of noise measurements for the selected structures of varistors designed for the continuous working voltage 280 V, 440 V and 660 V have been presented....
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Materiał węglowy ptrzymany na bazie karbonizowanego chitozanu domieszkowanego platyną = CARBON MATERIAL RECEIVED THROUGH CARBONIZATION OF CHITOSAN DOPED WITH PLATINUM
PublicationThe aim of this work was to investigate the impact of porous carbons with high nitrogen content onthe platinum catalyst performance properties. The system may be applied as well as cathodic catalyst for oxygenreduction in microbial fuel cells.We report a simple route for preparation of dispersed Platinum on the carbon support. Chitosan powder wasprotonated using aqueous solution of organic acid. The water from the pores was removed...
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Bioactive quaternary ammonium ionic liquids.
PublicationAn ionic liquid (IL) is an organic compound that contains at least one ionic bond. It consists of an organic cation and an organic or inorganic anion. It is an organic salt having a melting point below 100C. A very interesting group of IL are those with a long chain quaternary ammonium cation. They are formed by direct synthesis or by an anion-exchange reaction in quaternary ammonium halides. Popular and cheap precursors for the...
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The Influence of Iron Doping on Performance of SrTi1-XFexO3-δ Perovskite Oxygen Electrode for SOFC
PublicationSolid Oxide Fuel Cells (SOFC) are based on electrolytes and mixed ionic and electronic conductivity (MIEC) materials. The need to reduce costs causes an increase in interest of new compounds suitable for operating temperatures between 600 °C and 800 °C. The SrTi1-xFexO3 (STF) perovskite material is a perspective material that could be used for the oxygen electrodes. In this work STF materials with different content of iron (x =...
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A Method of Object Re-identiciation Applicable to Multicamera Surveillance Systems
PublicationThe paper addresses some challenges pertaining to the methods for tracking of objects in multi-camera systems. The tracking methods related to a single Field of Vision (FOV) are quite different from inter-camera tracking, especially in case of non-overlapping FOVs. In this case, the processing is directed to determine the probability of a particular object’s identity seen in a pair of cameras in the presence of places non-observed...
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Systematics of intelligent transport systems services
PublicationRecent years have seen a more intensified deployment of Intelligent Transport Systems (ITS) in Polish cities. Work is also underway on the implementation of ITS on the national roads within the National Traffic Management System (KSZR). The research project RID-4D (part of Road Innovations), is designed to fill the gap, which is the lack of systematics of ITS services in Poland. The paper presents a proposal of ITS services systematics,...
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Properties of Nasicon-based CO2 sensor with Bi8Nb2O17 reference electrode
PublicationGas sensors are useful for the carbon dioxide concentration monitoring in many applications. The major challenge is to develop a potentiometric sensor working without the necessity of a reference gas and without a need of the reference electrode encapsulation. Important issue is a selection of reference electrode material, which should provide stable reference potential. For example as reference electrode material in sensor based...