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Search results for: hydrogen dimer
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Mutually polarizable QM/MM model with in situ optimized localized basis functions
PublicationWe extend our recently developed quantum-mechanical/molecular mechanics (QM/MM) approach [Dziedzic et al., J. Chem. Phys. 145, 124106 (2016)] to enable in situ optimization of the localized orbitals. The quantum subsystem is described with ONETEP linear-scaling density functional theory and the classical subsystem – with the AMOEBA polarizable force field. The two subsystems interact via multipolar electrostatics and are fully...
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Electrochemically Induced Synthesis of Triphenylamine-based Polyhydrazones
PublicationTriphenylamine-based hydrazones were subjected to electropolymerization process that gave well conductive hydrazone based polymers. The first example of polyhydrazone formation during the electrochemical process was shown. The estimation of polymer structure was demonstrated using IR spectroelectrochemistry. The EPR spectroelectrochemistry allowed to explain why in some cases dimer couldn’t be formed. The results of electrochemical,...
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Die reaktion von tBu2P-P=P(Me)tBu2 mit [Fe2(CO)9] und [(n2-C8H14)2Fe(CO)3]
PublicationFosfanofosfinidenofosforan reaguje z nonakarbonylkiem diżelaza oraz z trikarbonylo(diokten)żelazem(0) dając mieszaniny produktów z których udało się wyizolować pochodne będące kompleksami dimeru di(tert)butylo-fosfinofosfini-denu i centrów koordynacji Fe(0).
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Microbiological condition of sediments and bottom water in the area of Gdańsk Deep in Gulf of Gdańsk
Open Research DataThis dataset contains the results of microbiological analysis of bottom water and bottom sediments in the area of Gdańsk Deep in Gulf of Gdańsk. The tested samples were collected at 5 sites on 15th of December 2007. 5 samples of bottom water and 10 samples of sediments were collected for microbiological testing. Each of these samples were analysed for...
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Assessment of hydrogenation of deposited metal of P 62 MR covered electrodes
PublicationThe determination of diffusible hydrogen content in deposited metal of P 62 MR covered electrodes for manual metal arc welding by mercury method was carried out. The test results indicate that covered electrodes 62 P MR grade generate a mean of 4.02 ml/100g of diffusible hydrogen in deposited metal, which is consistent with H5 class.
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N-Benzoyl-N'-phenylurea
PublicationPublikacja zawiera opis struktury krystalicznej i cząsteczkowej N-benzoilo-N'-fenylomocznika wyznaczonej metodą rentgenowskiej analizy strukturalnej. W krysztale dwie cząsteczki łączą się poprzez wiązania wodorowe typu N-H...O tworząc centrosymetryczne dimery.
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Electron attachment to representative cations composing ionic liquids
PublicationUsing ab initio electronic structure methods with flexible atomic orbital basis sets, we investigated the electronic structure and stability of reduction products of selected representative cations (C+) constituting ionic liquids. We found that an electron attachment to such cations leads to the neutral radicals, whereas a subsequent attachment of another (i.e., excess) electron leads to adiabatically stable anions only in two...
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Determination of moisture resistance of covered electrodes according to PN-EN ISO 14372
PublicationMoisture present in the electrode covering is one of the sources of diffusible hydrogen in welded joints. In order to study the diffusible hydrogen content in deposited metal, a stand for moisturizing covered electrodes, in accordance with the PN-EN ISO 14372 standard, was built. After the stand was completed, a test of moisturizing the electrodes was carried out and measurements of the diffusible hydrogen content in deposited...
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Excitation energy transport and trapping in concentrated solid solution of flavomononucleotide
PublicationW pracy analizowano bez promienisty transfer energii w stężonych stałych roztworach (folie polimerowe) FMN. W w/w roztworach występują świecące dimery FMN. Pokazano, że jedynie uwzględnienie powrotnego transferu energii pozwala zadowalająco wyjaśnić mechanizm przenoszenia energii w badanych układach.
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(μ-Tri-tert-butoxysilanethiolato)bis[(tetrahydrofuran)lithium(I)] and catena-poly[[bis(μ-tri-tert-butoxysilanethiolato)dilithium(I)]-μ-dimethoxyethane]: solvent coordination as the structure-forming factor.
PublicationOpisano syntezę oraz wyznaczono strukturę molekularną i krystaliczną dwóch solwatowanych tri-tert-butoksysilanotiolanów litu. W przypadku użycia tetrahydrofuranu obserwuje się tworzenie struktury, zawierającej izolowane dimery. Zastosowanie dimetoksyetanu powoduje utworzenie struktury łańcuchowej, którą można uznać za przykład polimeru koordynacyjnego.
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Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3-delta SOFC anodes
PublicationIn order to find a relationship between structural and electrical properties, niobium and yttrium doped SrTiO3 ceramics were prepared via solid-state reaction. The samples were sintered in hydrogen and air conditions. The samples were also fabricated with a pore-former to obtain highly porous specimens. The electrical properties of Nb-doped SrTiO3 samples and yttrium and niobium co-doped SrTiO3 were compared. The comparable electrical...
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Determination of changes in viscosity of pectin gel depending on shear rate (1.1 to 55 s-1).
Open Research DataThe rheological characteristic of pectin gel (with concetration 0,45% m/m, in three independent repetition of sample) was made on the basis of a viscosity measurement using a Brookfield viscometer, using LV SC4 - 25 spindle and shear rates from 1.1 to 55 s-1.The data allowed to characterize the used hydrogel preparations and assess their functional...
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Magnetic-dipole-to-electric-quadrupole cross-susceptibilities for relativistic hydrogenlike atoms in some low-lying discrete energy eigenstates
PublicationIn this paper we present tabulated data for magnetic-dipole-to-electric-quadrupole cross-susceptibilities (χ_{M1→E2}) for Dirac one-electron atoms with a pointlike, spinless and motionless nucleus of charge Ze. Numerical values of this susceptibility for the hydrogen atom (Z = 1) and for hydrogenic ions with 2 \leqslant Z \leqslant 137 are computed from the general analytical formula, recently derived by us (Stefanska, 2016), valid...
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Photocatalysts for Solar Energy Conversion
PublicationPhotocatalytic oxidation over suspended solid photocatalysts (e.g., titanium dioxide) has been proposed as a sustainable process for treatment and purification of water and wastewater as well as the process for photoconversion of solar energy to hydrogen, methane, and other low hydrocarbons. Solar radiation could be used to drive heterogeneous electrochemical reactions at the surface of an optically active photocatalyst (e.g.,...
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Determination of changes in viscosity of pectin gel depending on shear rate (1.7 to 85 s-1).
Open Research DataThe rheological characteristic of pectin gel (with concetration 0,25% m/m, in two independent repetitions) wasmade on the basis of a viscosity measurement using a Brookfield viscometer, using LV SC4 - 27 spindle and shear rates from 1.7 to 85 s-1, in temperature of 25 C degee .The data allowed to characterize the used hydrogel preparations and assess...
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Potential Energy Curves of Diatomic Alkali Molecules Datasets
PublicationThe datasets described in this article contain potential energy curves for several diatomic systems. The data was obtained via high-performance computing using MOLPRO, a system of ab initio programs for advanced molecular electronic structure calculations. The datasets allow to model bond lengths, energy levels, spectra and time-evolution of molecular dimers for which the data are presented.
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Preparation and X-ray structures of selected aminium thiosulfates
PublicationVarious types of aminium thiosulfates (1–6), including hydrates and mixed salts, have been obtained by the reaction of ammonium thiosulfate with amines. Tertbutylamine, cyclo-hexylamine and 1,6-diaminohexane gave crystals of (t-BuNH3)2S2O3·H2O (1), (c-C6H11NH3)2S2O3 (3) and {(NH4)2(H3NC6H12NH3)(S2O3)2} (6), respectively, which were investigated by X-ray structural analysis. Extensive hydrogen bonding of the N-H…O and N-H…S type...
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Zaawansowane utlenianie odcieków składowiskowych - przegląd metod
PublicationPrzedstawiono rozwiązania unieszkodliwiania odcieków składowiskowych metodami zaawansowanego utleniania, takimi jak: reakcja Fentona, utlenienie ozonem i nadtlenkiem wodoru, utlenienie elektrochemiczne, utlenienie w warunkach nadkrytycznych oraz mokre utlenienie powietrzem. Podstawy teoretyczne tych metod, ich efektywność oraz stosowane reagenty. Uwarunkowania stosowania poszczególnych metod.
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Evidence for solid state electrochemical degradation within a small molecule OLED
PublicationAcridone derivative have been synthesised and used as OLED (Organic Light Emitting Diode) emitters which were found to be electroactive. Electrochemical investigations showed a side reaction takes place inside an active layer which diminished the overall device efficiency. By using a dopant and host active layer architecture, the formation of the by product was removed. The by-product was identified as a σ-dimer formed inside an...
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Effect of Nanohydroxyapatite on Silk Fibroin–Chitosan Interactions—Molecular Dynamics Study
PublicationFibroin–chitosan composites, especially those containing nanohydroxyapatite, show potential for bone tissue regeneration. The physicochemical properties of these biocomposites depend on the compatibility between their components. In this study, the intermolecular interactions of fibroin and chitosan were analyzed using a molecular dynamics approach. Two types of systems were investigated: one containing acetic acid and the other...
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Interactions of protons with furan molecules studied by collision-induced emission spectroscopy at the incident energy range of 50–1000 eV
PublicationInvestigations of the ion-molecule reactions provide insight into many fields ranging from the stellar wind interaction with interstellar media, up to medicine and industrial applications. Besides the applications, the understanding of these processes is itself a problem of fundamental importance. Thus, interactions of protons with the gas-phase furan molecules have been investigated for the first time in the energy range of 50–1000...
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Corrosion and Cavitation Resistances of Low Alloy Steel After Frictional-Mechanical Treatment
PublicationPaper presents the results of the studies of wear, corrosion and cavitation resistances of the S355J2 low alloy medium carbon steel subjected to surface modification by friction-mechanical treatment, as tested in sea water simulated solution. To evaluate the effect of the surface treatment, the comparative studies of the corrosive properties of the steel before and after treatment have been considered. The treatment due to a severe...
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Why is the cubic structure preferred in newly formed ice?
PublicationMolecular dynamics was employed to explain the preference for the cubic structure in newly formed crystals of ice. The results showed that in supercooled liquid water the molecules connected by hydrogen bonds are more likely to adopt relative orientations similar to the ones characteristic for cubic ice. The observed preference for certain relative orientations of molecules in the hydrogen-bonded pairs results in the higher probability...
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Water-mediated long-range interactions between the internal vibrations of remote proteins
PublicationIt is generally acknowledged that the mobility of protein atoms and the mobility of water molecules in the solvation layer are connected. In this article, we answer the question whether a similar interdependence exists between the motions of atoms of proteins separated by the hydration layers of variable thickness. The system consisted of a kinesin catalytic domain and a tubulin dimer. It was studied using molecular dynamics simulations....
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The First Dinuclear Nickel(II) Thiosulfate Obtained From Oxidation of Tri-tert-butoxysilanethiol. Contributions to the Chemistry of Silicon-Sulfur Compounds No. 78[1]
PublicationPrezentowany związek {[Ni2(μ-S2O3)2(C7H9N)4-H2O]C7H8} (1) jest pierwszym tiosiarczanem metalu otrzymanym w wyniku utlenienia silanotiolu. Mechanizm tej reakcji zakłada powstawanie (RO)3SiSSSi(OR)3 jako jako produktu pośredniego. Bimetaliczny związek niklu(II) posiada dwie reszty tiosiarczanowe pełniące rolę liganda zarówno -S,O chelatującego jak i S-mostkującego łączącego oba centra metaliczne. Związek krystalizuje jako dimer z...
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Hydroliza enzymatyczna wybranych prób tłuszczów smażalniczych w obecności lipazy
PublicationWybrane próbki tłuszczów stosowanych do głębokiego smażenia w punktach gastronomicznych poddawano lipolizie in vitro w obecności lipazy trzustkowej. Tłuszcze te charakteryzowały się zróżnicowaną zawartością frakcji polarnej i spolimeryzowanych triacylogliceroli (TAG). Przebieg lipolizy kontrolowano metodą HPSEC. Stwierdzono, że tłuszcze ogrzewane ulegają lipolizie znacznie trudniej niż olej świeży. Najtrudniej ulegają lipolizie...
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Effect of temperature and composition on physical properties of deep eutectic solvents based on 2-(methylamino)ethanol – measurement and prediction
PublicationNovel deep eutectic solvents were synthesized using 2-(methylamino)ethanol as hydrogen bond donor with tetrabutylammonium bromide or tetrabutylammonium chloride or tetraethylammonium chloride as hydrogen bond acceptors. Mixtures were prepared at different molar ratios of 1:6, 1:8 and 1:10 salt to alkanolamine and then Fourier Transform Infrared Spectroscopy measurements were performed to confirm hydrogen bonds interactions between...
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ENVIRONMENTAL DEGRADATION OF DISSIMILAR AUSTENITIC 316L AND DUPLEX 2205 STAINLESS STEELS WELDED JOINTS
PublicationThe paper describes structure and properties of dissimilar stainless steels welded joints between duplex 2205 and austenitic 316L steels. Investigations were focused on environmentally assisted cracking of welded joints. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement was determined in slow strain rate tests (SSRT) with the strain rate of 2.2 × 10–6 s–1. Chloride-inducted SCC was determined in the...
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Application of H2O2 to optimize ammonium removal from domestic wastewater
PublicationThe paper presents the results of application of hydrogen peroxide (H2O2) for the optimization of the effects of ammonia nitrogen removal from domestic wastewater. The investigations were carried out at a model wastewater treatment plant consisting of a preliminary sedimentation tank and a sand filter with a horizontal flow of wastewater at a constant hydraulic load of 1.44 L/day. The efficiency of ammonia nitrogen removal was...
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Leydig cell tumor of testis, NOS - Male, 29 - Tissue image [4120730022884841]
Open Research DataThis is the histopathological image of TESTIS tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Configurational and Conformational Preferences in Stereoselective Acylations of N-Methyl-1,3-diaminopropane with Acyl Chlorides
PublicationEvidence for a stereoinduction profile of the reaction of N-methyl-1,3-diaminopropane with acyl chlorides was provided. A possibility to engage in intramol. CH2···HN and Cl···H-N interactions and the proton migration process to the methylamino group leads to the E secondary amides carrying the N···H+···N or N-H···N bridges, that show unusual spectroscopic images. Empirical relations between the ΔδC chem. shift differences,...
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Wet H2S corrosion and degradation of pipeline in amine regeneration system
PublicationThe paper presents the results of NDT examinations, metallographic tests and risk assessment of degradation related to corrosion of amine regeneration unit in a desulphurisation system. Intensive corrosion resulting from acid gases environment upon water condensation causes perforation of the pipeline. Detailed analysis reveals cracking related to the mechanism of wet H2S. Hydrogen penetration, resulting from the wet H2S process,...
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Wodór jako paliwo cz. 1
PublicationW artykule przedstawiono wodór jako nowoczesny nośnik energii oraz jego zastosowanie techniczne w ujęciu konwersji energii. Przybliżono jego odkrycie, właściwości oraz jego wykorzystanie od odkrycia do współczesności. Dokonano opisu budowy i zasady działania ogniw paliwowych. Omówiono ich podział przedstawiając zalety i wady każdego rozwiązania oraz ich zastosowanie techniczne w zależności od typu ogniwa.
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Analysis of a gene expression model
PublicationWe study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the number of active binding sites, the way in which dimers bind to DNA and time delay in translation process. For a simplified model that consist of three ordinary differential equations with time delay we derive conditions for stability of the positive steady state and for the...
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Strahlungslose Übertragung von Elektronenanregungsenergie bei zweidimensionalen lumineszierenden Systemen
PublicationAn expression for the photoluminescence (PhL) quantum yield of donors in two-dimensional systems as depending on the concentration ratio nD'/nA' of donors and acceptors has been obtained. In the particular case nD' ⪡ nA' the expression reduces to the form given by other authors. The obtained formula can also be applied to the description of the concentrational quenching of PhL when dimers act as acceptors. The theory has been...
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Apocrine adenocarcinoma - Female, 70 - Tissue image [6130730026844961]
Open Research DataThis is the histopathological image of BREAST tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 1000 slide scanner (20x magnification) and saved to DICOM format.
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Effect of water salinity on properties of multipass underwater wet manual metal arc welded joints
PublicationThe weldability of steel under the water is limited due to the influence of the environment. Water causes limited visibility, presence of the residual stresses, increasing the cooling rate, and increasing the diffusible hydrogen content in deposited metal, leading to the formation of brittle microstructures in heat-affected zone (HAZ). The paper presents the results of mechanical properties testing of S420G2+M steel welded joints...
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Bis(diisopropylammonium) thiosulfate and bis(tert-butylammonium) thiosulfate
PublicationTwo new dialkylammonium thiosulfates, namely bis(diisopropylammonium) thiosulfate, 2C6H16N+S2O3 2-, (I), and bis(tert-butylammonium) thiosulfate, 2C4H12N+S2O3 2-, (II), have been characterized. The secondary ammonium salt (I) crystallizes with Z = 4, while the primary ammonium salt (II), with more...
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Anion–water interactions of weakly hydrated anions: molecular dynamics simulations of aqueous NaBF4 and NaPF6
PublicationIn aqueous ionic solutions, both the structure and the dynamics of water are altered dramatically with respect to the pure solvent. The emergence of novel experimental techniques makes these changes accessible to detailed investigations. At the same time, computational studies deliver unique possibilities for the interpretation of the experimental data at the molecular level. Here, using molecular dynamics simulations, we demonstrate...
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Nanostructure of the laser-modified transition metal nanocomposites for water splitting
PublicationAlthough hydrogen is considered by many to be the green fuel of the future, nowadays it is primarily produced through steam reforming, which is a process far from ecological. Therefore, emphasis is being put on the development of electrodes capable of the efficient production of hydrogen and oxygen from water. To make the green alternative possible, the solution should be cost-efficient and well processable, generating less waste...
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Closer look into the structures of tetrabutylammonium bromide–glycerol-based deep eutectic solvents and their mixtures with water
PublicationIn recent years, deep eutectic solvents (DES) and it’s mixture with water have become more and more attention as green solvents used in chemistry. However, there are only a few theoretical studies on the mechanisms of pure DES and DES-water complex formation. Therefore, the structural properties of tetrabutylammonium bromide–glycerol-based deep eutectic solvents and their mixtures with water have been investigated by means of Molecular...
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Crystallization and preliminary X-ray analysis of the isomerase domain of glucosamine-6-phosphate synthase from Candida albicans
PublicationSyntaza glukozamino-6-fosforanu (EC 2.6.1.16) katalizuje pierwszy, praktycznie nieodwracalny etap w szlaku biosyntezy heksozoamin, którego produktem końcowym jest UDP-GlcNAc, kluczowy substrat dla tworzenia ściany komórkowej drobnoustrojów. Otrzymano kryształy domeny izomerazowej syntazy GlcN-6-P z Candida albicans, składającej się z reszt 346-712 (42 kDa). Analiza rentgenograficzna kryształu wykazała, że należy on do grupy przestrzennej...
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Phase separation in poly(butylene terephthalate)-based materials prepared by solid-state modification
PublicationThe morphology of a series of poly(butylene terephthalate) (PBT)/fatty acid dimer diol (FADD)-based copolyesters prepared by solid-state modi fi cation (SSM) was studied. It was shown that in copolyesters containing less than 10 wt% FADD two different phases, i.e. a PBT crystalline phase and a PBT-rich amorphous phase, are present. The FADD residues were more or less homogeneously distributed throughout the interlamellar regions....
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Performance and emission characteristics of diesel engines running on gaseous fuels in dual-fuel mode
PublicationConventional fossil fuels are being substituted with alternative green fuels because of their greenhouse gas emissions and pollution problems, which pose a severe threat to the environment. Several studies have reported the usage of biodiesel and gaseous fuels in both single and dual-fuel modes. Gaseous fuels such as producer gas, biogas, syngas, and hydrogen produced from renewable biomass could potentially be used along with...
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X-Ray photoemission spectroscopy measurements of the Nb-V-Sr-O ceramics
Open Research DataNiobium doped strontium vanadate based perovskite SrV1-xNbxO3-δ materials were prepared via conventional solid state reaction (SSR) method. For comparison, different samples with a various amount of niobium dopant in the structure were synthesized; x = 0; 0,2; 0,5; 0,8 and 1. Samples were sintered by two-steps: first under a pure hydrogen (purity >99.999%)...
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Leszek Ziemczonek dr
PeopleUniversity education 1973-1978 – Nicolaus Copernicus University in Toruń, University of Gdańsk in Gdańsk, Mathematical Physics, M. Sc. 1979 – Diploma of Postgraduate Studies, Pedagogics 1989 – Institute of Physics, Polish Academy of Sciences in Warsaw, Theoretical Physics, Ph. D. 2010-2012 – Diploma of Postgraduate Studies, Mathematics Training: · 09.1983 – Trieste (Italy) – International Centre for Theoretical Physics...
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Ceria Based Protective Coatings for Steel Interconnects Prepared by Spray Pyrolysis
PublicationStainless steels can be used in solid oxide fuel/electrolysis stacks as interconnects. For successful long term operation they require protective coatings, that lower the corrosion rate and block chemical reactions between the interconnect and adjacent layers of the oxygen or the hydrogen electrode. One of the promising coating materials for the hydrogen side is ceria. Using standard sintering techniques, ceria sinters at around...
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Degradation of Rhodamine dyes by Advanced Oxidation Processes (AOPs) – Focus on cavitation and photocatalysis - A critical review
PublicationThis review evaluates selected advanced oxidation processes (AOPs) - cavitation and photocatalysis - successfully used for wastewater treatment towards degradation of Rhodamine (Rh) dyes. Reactor configuration and impact of process parameters and oxidants addition (hydrogen peroxide, ozone, persulfates) on degradation effectiveness along with degradation mechanisms are discussed. Best technologies provide 100% degradation within...
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Structural properties of hydration shell around various conformations of simple polypeptides
PublicationIn this paper we investigate structural properties of water within the solvation shell around the peptide core created by a well-defined conformation of polypeptide chain. The following secondary structures are investigated: linear (straight chain), and three helices PII (polyproline-like), 310, and α. We propose using the two-particle contribution to entropy as a rational measure of the water structural ordering within the solvation...
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Interaction of amphotericin B with phospholipids in the model membrane - molecular dynamics study.
PublicationAmfoterycyna B jest antybiotykiem używanym w leczeniu układowych infekcji grzybowych. Jej mechanizm działania polega na tworzeniu kanałów wewnątrz błon lipidowych. W przedstawianej pracy publikowane są wyniki symulacji przeprowadzonej dynamiką molekularną monomerycznej i dimerycznej formy antybiotyku wewnątrz błony lipidowej zbudowanej z cząsteczek DMPC. Wyniki te wskazują, że powinowactwo cząsteczek amfoterycyny wewnątrz dimeru...