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Wyniki wyszukiwania dla: PHOSPHA-WITTIG REACTION
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Influence of the Square Wave Voltage on Dynamical Properties of a Flat Voltammetric Electrode in the Time Domain by the Electrochemical Reversible Reaction
PublikacjaIn this article there is a presentation of the analysis of the polarizing voltage shape influencing dynamic properties of voltammetric electrodes when on their surface reversible reaction takes place in the time domain. The electrode polarization with linearly increasing voltage and with a square component, was analyzed. The analysis that were conducted showed that the voltammetric electrode behaves like a first order transducer....
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Spectacular Oxygen Evolution Reaction Enhancement Through Laser Processing of the Nickel-Decorated Titania Nanotubes
PublikacjaThe selective, laser-induced modification of the nickel-decorated titania nanotubes provides remarkable enhancement toward oxygen evolution reaction. Particularly, the irradiation of the laterally spaced crystalline TiO2 nanotubes, results in the formation of the tight closure over irradiated end, preserving their hollow interior. The shape of the absorbance spectra is modulated along with applied energy, and the new absorption...
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Spectacular Oxygen Evolution Reaction Enhancement through Laser Processing of the Nickel‐Decorated Titania Nanotubes
PublikacjaThe selective, laser‐induced modification of the nickel‐decorated titania nanotubes provides remarkable enhancement toward oxygen evolution reaction. Particularly, the irradiation of the laterally spaced crystalline TiO2 nanotubes, results in the formation of the tight closure over irradiated end, preserving their hollow interior. The shape of the absorbance spectra is modulated along with applied energy, and the new absorption...
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Short-term Price Reaction to Involuntary Bankruptcies Filed in Bad Faith: Empirical Evidence from Poland
PublikacjaPurpose: Assessing the reaction of the prices of shares of companies listed in the Warsaw Stock Exchange to the public disclosure of information about the filing a bankruptcy petition in bad faith by creditors. Design/Methodology/Approach: Event study analysis. Findings: It can therefore be assumed that the filing of an unfounded bankruptcy petition does not, in the short term, have a statistically significant negative impact on...
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The influence of thermal treatment on electrocatalytic properties of Mn-Co nanofilms on nickel foam toward oxygen evolution reaction activity
PublikacjaThis work evaluates electrodeposited and differently treated Mn-Co catalysts for their oxygen evolution reaction activity. Catalysts are evaluated in the as-deposited and heat treated state: after 350 C and 600 C. Results show that the highest electrochemical activity is obtained for the as-deposited Mn-Co oxyhydroxide, which possibly possess a layered double hydroxide structure. After the heat treatment process, especially after...
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Kinetics of Cross-Linking Reaction of Epoxy Resin with Hydroxyapatite-Functionalized Layered Double Hydroxides
PublikacjaThe cure kinetics analysis of thermoset polymer composites gives useful information about their properties. In this work, two types of layered double hydroxide (LDH) consisting of Mg2+ and Zn2+ as divalent metal ions and CO32− as an anion intercalating agent were synthesized and functionalized with hydroxyapatite (HA) to make a potential thermal resistant nanocomposite. The curing potential of the synthesized nanoplatelets in the...
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Acid-aided epoxy-amine curing reaction as reflected in epoxy/Fe3O4 nanocomposites: Chemistry, mechanism, and fracture behavior
PublikacjaThis work seeks to answer the question whether or not the presence of acid functional groups accelerate epoxyamine curing reaction. Epoxy/Fe3O4 nanocomposite was considered as a case, where discussions are based on chemistry, mechanism behind curing reactions and fracture behavior influenced by acid assistance to crosslinking. Fe3O4 magnetic nanoparticles (MNPs) with nanosilica decorative layer (B-MNP) were synthesized and subsequently...
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Solvent Impact on the Diversity of Products in the Reaction of Lithium Diphenylphosphide and a Ti(III) Complex Supported by a tBu2P–P(SiMe3) Ligand
PublikacjaWe present two important trends in the reactivity ofthe titanium complex [MeNacNacTi(Cl){η2-P(SiMe3)-PtBu2}](MeNacNac− = [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2Ph)with nucleophilic reagents RLi (R = Ph2P,tBuO, (Me3Si)2N, andtBu2N) depending on the reaction medium. Reaction in nonpolarsolvent (toluene) leads to three main products: via an autoredoxprocess and nucleophilic substitution at the Ti-atom to afford theTi(IV) complex [MeNacNacTi(R){η2-P-PtBu2}]...
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Fast method for the determination of the charge transfer coefficient of an electrode reaction
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Carbon Nanohorns as Reaction Nanochambers – a Systematic Monte Carlo Study
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The overabundance of excited hydrogen atoms produced in the H2++ furan reaction
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Methane formation over TiO2–based photocatalysts: reaction pathways
PublikacjaThe effects of organic impurities adsorbed or incorporated into semiconductors structure on the photocatalytic products are noteworthy. For this purpose, the as-prepared Ag, Au and Pdmodified TiO2 samples were exposed to UV-vis irradiation in various gas atmospheres (CO2, N2, 600 ppm CO2 in N2, and 13CO2) in order to clarify the route of CH4 formation in the process of photocatalytic CO2 reduction. In the presented research it...
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Photochemical and thermal reaction of intermediates in the phenylnitrene rearangment inside a hemicarcerand
PublikacjaBroadband irradiation (λ > 320 nm) of hemicarceplex H1 between −74 °C and −84 °C, produces encapsulated didehydroazepine (2), triplet phenylnitrene (3PN), 2-azabicyclo[3.2.0]hepta-1,3,6-triene (6), and 4-azaspiro[2.4]hepta-1,4,6-triene (7). The highly strained anti-Bredt imine 6 is formed from 2 via a photochemical four-electron electrocyclization. Under the irradiation conditions, 6 rearranges further to azaspirene 7. In addition,...
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Promotion of borophene/NiO-based electrocatalyst for oxygen evolution reaction
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Promotion of borophene/NiO-based electrocatalyst for oxygen evolution reaction
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Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight
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Dynamic electrochemical impedance spectroscopy of the first order electrode reaction
PublikacjaCiągłe transformaty STFT sinusoidalnego sygnału pobudzenia i odpowiedzi prądowej zostały wyznaczone dla reakcji elektrodowej pierwszego rzędu. Wyznaczono impedancję elektrody w łącznej dziedzinie czasu i częstotliwości. Wykonano pomiary dla reakcji redukcji Cd(II) na rtęciowej elektrodzie kroplowej w funkcji potencjału. Przedstawiono możliwość wyznaczenia chwilowych widm impedancyjnych. Opisano zależność rezystancji przeniesienia...
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Frequency distribution of chemical oscillations in the closed Belousov Zhabotinsky reaction.
PublikacjaW publikacji przedstawiono wykorzystanie metody STFT (krótkoczasowej transformaty Fouriera) do analizy oscylacji chemicznych. Badano rejestry potencjałowe reakcji Biełousowa Żabotyńskiego. Wykazano niestacjonarność analizowanych przebiegów. Wykazano liniową zależność pomiędzy częstotliwością oscylacji a stężeniem jednego z komponentów reakcji (bromian potasu). Udowodniono przydatność analizy czasowo-częstotliwościowej do analizy...
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Tailoring a low-energy ball milled MnCo2O4 spinel catalyst to boost oxygen evolution reaction performance
PublikacjaThe development of cost-efficient oxygen evolution reaction (OER) catalysts is one of the most important tasks facing modern techniques for hydrogen production. In this work, for the first time, a low-energy ball milling process of MnCo2O4 (MCO) spinel powders, with a mechanical modification time exceeding 1 day was used. After 6 days of ball-milling, the obtained overpotential of the electrocatalyst reached the value of 375 mV...
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Direct measurements of odorous volatile organic compounds present in biosolids cakes by Proton Transfer Reaction – Mass Spectrometry Technique
PublikacjaThis paper show the results of investigation of concentration of odorous chemical compounds emitted upon ageing of anaerobically stabilised biosolids that could contribute to the overall odour character of nuisance emissions. Biosolids samples from wastewater treatment plant were collected in spring time. Concentrations of volatile organic compounds using a US EPA flux hood and Proton Transfer Reaction-Time of Flight-Mass Spectrometry...
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Free-standing TiO2 nanotubes decorated with spherical nickel nanoparticles as a cost-efficient electrocatalyst for oxygen evolution reaction
PublikacjaHere, we report significant activity towards the oxygen evolution reaction (OER) of spherical nickel nanoparticles (NPs) electrodeposited onto free-standing TiO2 nanotubes (TNT) via cyclic voltammetry. It has been shown that simple manipulation of processing parameters, including scan rate and number of cycles, allows for formation of the NPs in various diameters and amounts. The polarization data with respect to transmission electron...
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A new method for real-time monitoring of volatiles in frying fumes using proton transfer reaction mass spectrometry with time-of-flight analyse
PublikacjaTo safeguard the consumers’ well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled....
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The impedance of hydrogen oxidation reaction in a proton exchange membrane fuel cell in the presence of carbon monoxide in hydrogen stream
PublikacjaEvaluation of performance of a proton exchange membrane fuel cell, which is affected by carbon monoxide that pollutes the hydrogen stream, was presented. This influence was studied for carbon monoxide concentration of 125–325 ppb, which are close to values specified in ISO 14687:2019 standard. Performed studies provided crucial information for further development of fuel cell as an energy source for automotive application. Impedance...
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The role of aluminium in metal–organic frameworks derived carbon doped with cobalt in electrocatalytic oxygen evolution reaction
PublikacjaWater electrolysis is one of the most crucial processes in the development of new energy sources, where ultra-clean fuel is produced - hydrogen. Oxygen evolution reaction (OER) is the sluggish process of overall water splitting. Therefore, this study presents the design, characterization and electrochemical study of cobalt-based electrocatalysts embedded into porous carbons derived from an Al-metal–organic...
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On-line assessment of oil quality during deep frying using an electronic nose and proton transfer reaction mass spectrometry
PublikacjaWe describe a novel method for the quality assessment of oil utilized for deep frying. The method is based on the analysis of frying fumes using a custom electronic nose. The quality score could be obtained after less than 3 min of analysis and without interrupting the frying process or sampling the oil directly. The obtained results were correlated with the peroxide value using a multivariate linear regression model. The most...
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A Novel [4+2] Cycloaddition Reaction Involving Lawesson’s Reagent. Structure and Specific Fragmentations of a New Cyclic 1,2-Thiaphosphinane-4-one
PublikacjaA crude morpholine enamine of acetone treated with Lawesson’s reagent unexpectedly yielded a six-membered thiaphosphinane-4-one. This compound is the first example of a new class of heterocycles. It has been proven that it is formed from 4-methyl-2-morpholino-1,3-pentadiene which is usually present in crude morpholine enamine batches. A mechanism of this regioselective reaction was postulated and a characteristic chair-like conformation...
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Theoretical description of fundamental-harmonic impedance of a two-step electrode reaction
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Studies on the application of the Passerini reaction and enzymatic procedures to the synthesis of tripeptide mimetics
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Kinetic studies of complexation reaction of polyoxaalkyl phosphates with Fe(III) in ethanol
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Reduction of the reaction torque of an in-line four-cylinder four-stroke engine
PublikacjaW pracy przedstawiono zarówno dokładne jak i uproszczone zależności na przebieg momentu reakcyjnego silnika, jedno i wielocylindrowego, przenoszonego na ramę pojazdu lub fundament. Wyprowadzono zależność na wartość przesunięcia wałków wyrównoważających zapewniającą całkowite wyeliminowanie wpływu sił bezwładności na przebieg momentu reakcyjnego w silnikach czterosuwowych czterocylindrowych. Wprowadzono kryteria doboru optymalnej...
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Photocatalytic performance of titania nanospheres deposited on graphene in coumarin oxidation reaction
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Fused FeCo catalysts for hydrogen production by means of the ammonia decomposition reaction
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Synthesis of antimicrobial silver nanoparticles through a photomediated reaction in an aqueous environment
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Reaction of thio and seleno phosphoric acid derivatives with O-thioacylated hydroxylamine
PublikacjaZbadano reakcję siarkowych i selenowych analogów kwasu O,O-neopentylidenofosforowego z O-tiopiwaloilo-N-tert-butylohydroksyloaminą, w której to następuje rozszczepienie wiązania N-O. Znaleziono korelację pomiędzy potencjałem utleniającym anionu pochodnej kwasu fosforowego a przebiegiem badanej reakcji.
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Changes in mussel Mytilus galloprovincialis protein profile as a reaction of water pollution
PublikacjaW pracy przedstawiono zmiany w profilu białkowym małża Mytilus galloprovincialis jako odpowiedź na zanieczyszczenia wody. Określono pojemność przeciwutleniającą z wykorzystaniem testu TEAC. Stwierdzono różnice w poziomie inhibicji w białku pochodzącym od małży zebranych z regionów zanieczyszczonych w stosunku do małży pochodzących z regionów czystych.Zawartość cynku i kadmu w białkach małży pochodzących z regionów zanieczyszczonych...
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Properties of a lithium solid electrolyte gas sensor based on reaction kinetics
PublikacjaW artykule przedstawiono zasadę działania, budowę i właściwości czujnika gazu na bazie elektrolitu stałego z mobilnymi jonami litu. Czujnik został przygotowany w technologii grubowarstwowej. Przedstawiono wyniki badań czujnika w mieszaninach gazów toksycznych.
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N-doped mesoporous carbon nanosheets obtained by pyrolysis of a chitosan–melamine mixture for the oxygen reduction reaction in alkaline media.
PublikacjaBy simple thermal decomposition of low-cost precursors (chitosan, melamine) in an inert atmosphere, nitrogen-doped porous carbonaceous materials were prepared. The samples pyrolyzed at 700 C are composed of mainly mesoporous nitrogen-doped carbon nanosheets and partially graphitized carbon. The nanosheets contain a disordered area due to the strain imposed by the presence of nitrogen and/or oxygen groups in their structure. Some...
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The hydrogen evolution reaction (HER) performance of some FTO/MoS2/SnO2 electrodes
Dane BadawczeTo demonstrate the electrochemical performance of the FTO/MoS2/SnO2 for HER (hydrogen evolution reaction), the LSV (linear sweep voltammetry) was performed. The polarization curves of the obtained composite were measured in 1 M H2SO4 at room temperature with a scan rate 10 mV/s. For comparison, the LSV for the FTO, pure MoS2 and Pt plate electrode were...
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Victor Eremeev prof. dr hab.
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The Quaternization Reaction of 5-O-Sulfonates of Methyl 2,3-o-Isopropylidene-β-D-Ribofuranoside with Selected Heterocyclic and Aliphatic Amines
PublikacjaThe synthesis of N-((methyl 5-deoxy-2,3-O-isopropylidene-β-D-ribofuranoside)-5-yl) ammonium salts are presented. To determine the effect of the nucleophile type and outgoing group on the quaternization reaction, selected aliphatic and heterocyclic aromatic amines reacted with: methyl 2,3-O-isopropylidene-5-O-tosyl-β-D-ribofuranoside or methyl 2,3-O-isopropylidene-5-O-mesyl-β-D -ribofuranoside or methyl 2,3-O-isopropylidene-5-O-triflyl-β-D-ribofuranoside...
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Tuning of eg electron occupancy of MnCo2O4 spinel for oxygen evolution reaction by partial substitution of Co by Fe at octahedral sites
PublikacjaTo study the effect of partial Co substitution by Fe in the B site of MnCo2O4 spinel on its physicochemical and electrochemical properties, a series of MnCo2-xFexO4 powders (x=0.125; 0.250; 0.500; 0.750; 1.000) were synthesized by means of the sol-gel method. The produced powders were characterized by powder X ray diffraction (pXRD), scanning and transmission electron microscopy (SEM & TEM) coupled with energy dispersive spectroscopy...
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Reaction of 4-benzylidene-2-methyl-5-oxazolone with amines, Part 2: Influence of substituents in para-position in the phenyl ring and a substituent on amine nitrogen atom on the reaction kinetics
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Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-D-galactosidase from Arthrobacter sp. 32cB
PublikacjaArthbetaDG is a dimeric, cold-adapted beta-D-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The...
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The Effect of Cobalt Incorporation into Nickel–Iron Oxide/(oxy)hydroxide Catalyst on Electrocatalytic Performance Toward Oxygen Evolution Reaction
PublikacjaThis work presents a study on the influence of the addition of cobalt into state-of-the-art nickel–iron (NiFe) mixed oxides/hydroxides/(oxy)hydroxides on their structural and morphological properties, and oxygen evolution reaction (OER) catalytic activity. A one-step electrodeposition process is performed without any additives to fabricate NiFe and x cobalt-doped nickel/iron (xCoNiFe) layer-double-hydroxide catalysts directly on...
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Monitoring of odors emitted from stabilized dewatered sludge subjected to aging using proton transfer reaction–mass spectrometry
PublikacjaOne of the potential emission sources of odorous compounds from wastewater treatment plants is sludge processing. The odorous compounds released from dewatered sludge can result in odor nuisance. This study concerns the use of flux hood chamber combined with proton transfer reaction—time of flight—mass spectrometry (PTR-MS) technique for periodical monitoring of odorous compounds emitted from aged, stabilized dewatered sludge samples...
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Analysis of volatile fraction of sweetie (Citrus maxima × Citrus paradisi) and its parent fruit using proton transfer reaction mass spectrometry
PublikacjaThe quality of the fruit is affected by several main ingredients and the aroma plays a fundamental role during the selection of fruit by consumers. In the case where several fruit have similar aromas and only one of them has specific health properties, it is very important to find the differences in the volatile organic compounds (VOCs) composition to distinguish these samples. Such situations are often found for hybrid fruit....
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Online Volatile Compound Emissions Analysis Using a Microchamber/Thermal Extractor Coupled to Proton Transfer Reaction-Mass Spectrometry
PublikacjaIndoor air is a complex and dynamic mixture comprising manifold volatile organic compounds (VOCs) that may cause physiological and/or psychological discomfort, depending on the nature of exposure. This technical note presents a novel approach to analyze VOC emissions by coupling a microchamber/thermal extractor (μ-CTE) system to a proton transfer reaction-mass spectrometer (PTR-MS). This configuration provides an alternative to...
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In-Reactor Polypropylene Functionalization─The Influence of Catalyst Structures and Reaction Conditions on the Catalytic Performance
PublikacjaTo unravel the relationship between silylene-bridged metallocene catalyst structures and polymerization conditions and their effect on the performance in in-reactor functionalization of polypropylene, the behaviors of rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2/MMAO, rac-Me2Si(Ind)2ZrCl2, rac-Me2Si(2-Me-4-Ph-Ind)2HfCl2, and rac-Me2Si(Ind)2HfCl2 in propylene/aluminum alkyl-passivated 10-undecen-1-ol copolymerization were compared. Kinetic analysis...
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APPLICATION OF COHEN'S CLASS TIME-FREQUENCY DISTRIBUTIONS IN THE BELOUSOV–ZHABOTINSKY REACTION ANALYSIS
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Descriptors to Predict Dye‐Sensitized Semiconductor Based Photocatalyst for Hydrogen Evolution Reaction
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