Search results for: IONS
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Corncob-supported calcium oxide nanoparticles from hen eggshells for cadmium (Cd-II) removal from aqueous solutions; Synthesis and characterization
PublicationThis study investigated the efficient removal of cadmium ions from aqueous solutions using calcium oxide nanoparticles (CaO NPs) synthesized from waste hen eggshells using a Sol-gel method and supported on corncob bio-adsorbent. The synthesized CaO NPs were characterized using FT-IR, XRD, specific surface area, and TGA. Batch adsorption experiments were conducted to examine the influence of process parameters such as adsorbent...
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Structure, luminescent properties and FDTD simulation of TeO2-BaO-Bi2O3-Ag:Ln3+ glass-ceramics system
PublicationTeO2-BaO-Bi2O3-Ag glass systems (TBB) co-doped with terbium and europium ions have been successfully synthesized through conventional melt-quenching technique. Heat treatment procedure at 350 °C has been conducted in order to synthesize silver nanoparticles embedded in TBB glass matrix. Structural measurements involved XRD studies that revealed no crystallization of glass structure after heat treatment at elevated temperatures....
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High-performance activation of ozone by sonocavitation for BTEX degradation in water
PublicationThis work presents a novel advanced oxidation process (AOP) for degradation of emerging organic pollutants – benzene, toluene, ethylbenzene and xylenes (BTEXs) in water. A comparative study was performed for sonocavitation assisted ozonation under 40–120 kHz and 80–200 kHz dual frequency ultrasounds (DFUS). Based on the obtained results, the combination of 40–120 kHz i.e., low-frequency US (LFDUS) with O3 exhibited excellent oxidation...
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Austenitic stainless steel sensitization
Open Research DataHigh-alloy steels, thanks to their composition and content of appropriate alloying additives, are characterized by increased resistance to many corrosive environments. However, this is due to the increased sensitivity of the described construction materials to specific environmental conditions during their use. An example may be the increased susceptibility...
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The luminescence study of Ga1.98–xAlxO3:0.02Cr3+ coumpounds.
Open Research DataA chemical and mechanical pressure-induced photoluminescence tuning method was developed through structural evolution and hydrostatic pressure involving phase transition. A series of Ga1.98−xAlxO3:0.02Cr3+ phosphors were synthesized by collaborators from National Taiwan University. Structural evolution reveals a crystal phase change with the incorporation...
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Conductivity and viscosity changes of imidazolium ionic liquids induced by H2O and CO2
PublicationSeveral solutions of ionic liquids based on 1-ethyl-3-methylimidazolium cation saturated and unsaturated with carbon dioxide were prepared and characterized by electrochemical impedance spectroscopy. The in fluence of ILs saturation on its electrical conductivity was determined. Additionally, the in fluence of the water presence and variations of temperature on electrical properties of ionic liquids were investigated. Changes of...
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Lower rim substituted p-tert-butyl-calix[4]arene. Part 17. synthesis, extractive and ionophoric properties of p-tert-butylcalix[4]arene appended with hydroxamix acid moieties
PublicationThe synthesis and characterization of four p-tert-butylcalix[4]arene-hydroxamic acidc are reported. The dependence of the metal ion binding, assessed by liquid extraction of the metal nitrates from water into dichloromethane in individual and competitive experiments, on the ligand structure, is presented. The results showed that those ligands could be successfully used in separation process of trnasition and heavy metals often...
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Synthesis and application of tetrazole di and triamide derivatives in ion-selective membrane electrodes
PublicationA number of tetrazole diamides and triamides have been synthesized and applied as ion carries in ion-selective membrane electrodes. Their selectivity and sensitivity were studied towards alkali, alkaline earth, transition and heavy metal cations. it was found that membranes doped with 3 and 2-nitrophenyl octyl ether exhibit an almost theoretial Nernstian response for NH+ over relatively wide concentration range. Elestrodes with...
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The chemical and mechanical pressure influence on chromium luminescence
Open Research DataIn this study, we aim to compare the changes in the luminescence properties of Ga2O3:Cr3+ modified by Al or Sc ion substitution (chemical pressure) and hydrostatic pressure. We find the same behavior for Ga2–xAlxO3:Cr3+ and different behavior for Ga2–xScxO3:Cr3+ in terms of the optical properties under chemical and mechanical pressure. We consider Al...
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Non-enzymatic glutathione-mediated conjugation of unsymmetrical bisacridine C-2028 with anticancer activity
Open Research DataThe presented data complement the studies on the interplay between C-2028 (anticancer-active unsymmetrical bisacridine) and the glutathione S-transferase/glutathione (GST/GSH) system.
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Limiting Partial Molar Volumes of Tetra-n-Alkylammonium Perchlorates in N,N-dimethylacetamide, Triethylphosphate and Dimethyl Sulfoxide at 298.15 K
PublicationThe densities of tetraalkylammonium perchlorates R4NClO4(R = methyl, or ethyl, or propyl, or butyl) and ammonium perchlorate solutions in N, N - dimethylacetamide, dimethyl sulfoxide, and triethylphosphate have been measured over the whole composition range atT = 298.15 K. From these densities, apparent and limiting partial molar volumes of the electrolytes and ions...
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Antioxidant properties of ferrous flavanol mixtures
PublicationInteraction of metal, especially iron ions with flavanols is considered as an important feature of these compounds and is believed to contribute to their both antioxidant and prooxidant properties. The aim of this study was to examine how Fe2+ binding to form a 4:1 (flavanol:Fe2+) mixtures affects the antioxidant properties of flavanols. ABTS∗ scavenging, protection against fluorescence bleaching induced by AAPH and hypochlorite,...
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Proton transfer reactions for ionized water clusters
PublicationCalculations of formation energies of the ionized water clusters and energies of reactions between small (including less than eight water molecules) neutral and positively ionized water clusters are presented. Moreover, we discuss some reaction paths between neutral and positively charged dimers, trimers and tetramers and proton transfer reactions (PTR) between cyclic clusters and H3O+ ions which can appear in beam experiments...
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Studies on Treatment of Bitumen Effluents by Means of Advanced Oxidation Processes (AOPs) in Basic pH Conditions
PublicationThe paper presents the results of studies on chemical treatment of effluents from production of bitumen of petroleum origin. Due to the presence of sulfide ions, the pH of these effluents is strongly alkaline. Several Advanced Oxidation Processes (AOPs) were studied, including the use of hydroxyl and sulfate radicals oxidants, the hydrodynamic cavitation as well as sonocavitation. The best processes allow to obtain 45% reduction...
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Studies on treatment of bitumen effluents by means of Advanced Oxidation Processes (AOPs) in basic pH conditions
PublicationThe paper presents the results of studies on chemical treatment of effluents from production of bitumen of petroleum origin. Due to the presence of sulfide ions, the pH of these effluents is strongly alkaline. Several Advanced Oxidation Processes (AOPs) were studied, including the use of hydroxyl and sulfate radicals oxidants, the hydrodynamic cavitation as well as sonocavitation. The best processes allow to obtain 45% reduction...
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237Np Mössbauer effect study on NpFeAsO
PublicationWe report 237Np Mössbauer measurements on NpFeAsO. The Np atoms were found to occupy only one crystallographic site. The value of the isomer shift (δ ∼ 9.1 mm s−1 versus NpAl2) indicates a 5f4 electronic configuration (Np3+ ions). The magnetic ordering of the Np sublattice below 60 K is established and the saturated ordered magnetic moment is determined to be 1.73μB at 3.6 K. The unique set of hyperfine parameters exclude a modulated...
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Synthesis, characterization and application of cross-linked functional terpolymer through epoxy group as sorbent for extraction of cadmium from waters and foods: Multivariate optimization
PublicationThe purpose of this study was to develop a selective sorbent for cadmium ions (Cd(II)) enrichment in orbital shaker assisted solid phase microextraction (OS-SPME) from different aqueous and food samples. A maleic anhydride-styrene-glycidyl methacrylate (MA-St-GMA) terpolymer was synthesized and characterized in detail. Experimental variables of sample preparation step were optimized using a central composite design (CCD). The final...
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Structural investigations of niobium-doped bioactive calcium-phosphate glass-ceramics by means of spectroscopic studies
PublicationSynthetic calcium-phosphate based glasses and glass-ceramics play a crucial role in the development of tissue engineering. These materials have a high biocompatibility with biological analogues, excellent ability to undergo varying degrees of resorbability and due to their non-toxicity and relatively high bioactivity they are commonly used as bone and dental implants. A substantial research effort is devoted to improve synthetic...
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Controlling the europium oxidation state in diopside through flux concentration
PublicationThis paper explores the connection between the H3BO3 flux concentration and the co-existence of Eu2+ and Eu3+ dopants within CaMgSi2O6 crystals (diopside). The samples were synthesised using a solid-state synthesis method under varying atmospheric conditions, including oxidative (air), neutral (N2), and reductive (H2/N2 mixture) environments. Additionally, some materials underwent chemical modification by partially substituting...
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Deposition of phosphate coatings on titanium within scaffold structure
PublicationPurpose: Existing knowledge about the appearance, thickness, and chemical composition of phosphate coatings on titanium inside porous structures is insufficient. Such knowledge is important for the design and fabrication of porous implants. Methods: Metallic scaffolds were fabricated by selective laser melting of 316L stainless steel powder. Phosphate coatings were deposited on Ti sensors placed either outside the scaffolds or...
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Support Materials of Organic and Inorganic Origin as Platforms for Horseradish Peroxidase Immobilization: Comparison Study for High Stability and Activity Recovery
PublicationIn the presented study, a variety of hybrid and single nanomaterials of various origins were tested as novel platforms for horseradish peroxidase immobilization. A thorough characterization was performed to establish the suitability of the support materials for immobilization, as well as the activity and stability retention of the biocatalysts, which were analyzed and discussed. The physicochemical characterization of the obtained...
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On thio‐substituted N‐heterocyclic arsines
PublicationMetathesis of N-heterocyclic chloroarsines with sulfur-based nucleophiles furnished thio-substituted 1,3,2-diazarsolidines and 1,3,2-diazarsolenes. Crystallographic and NMR spectroscopic studies revealed that a thiocyanato-diazarsolene exhibits a salt-like structure composed of weakly interacting thiocyanate and arsenium ions, while the remaining products formed neutral molecules. The structural data indicate that the heterocyclic...
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Dissociation of furan-2-carboxylic acid by low energy electrons
PublicationElectron attachment to molecular target can lead to a variety of negative fragment ions. We experi- mentally probe the main dissociative electron attachment channels in furan-2-carboxylic acid (C3H3O2 − COOH) - a molecular target composed of two important structural units: a furan ring and a carboxylic group. In our studies we utilise nearly mono-energetic electrons at electron energies from 0 eV up to 15 eV. Our detection setup...
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Predicting the viscosity and electrical conductivity of ionic liquids on the basis of theoretically calculated ionic volumes
PublicationSelected physical properties of the ionic liquids might be quantitatively predicted based on the volumes of the ions these systems are composed of. It is demonstrated that the ionic volumes calculated using relatively simple theoretical quantum chemistry methods can be utilised to estimate the viscosities and electrical conductivities of various commonly used ionic liquids. The fitting formulas of the exponential form are offered...
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The domination of ionic conductivity in tetragonal phase of the organometal halide perovskite CH3NH3PbI3-xClx
PublicationOrganometal trihalide perovskites have recently gained extreme attention due to their high solar energy conversion in photovoltaic cells. Here, we investigate the contribution of iodide ions to a total conductivity of the mixed lead halide perovskite CH3NH3PbI3−xClx with a use of the modified DC Hebb–Wagner polarization method. It has been identified that an ionic conductivity dominates in tetragonal phase which is associated with room...
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In Vitro Dissolution of Na-Ca-P-Oxynitrides
Publication: Sodium-calcium-phosphate based oxynitride glasses and glass-ceramics doped with Mg, Si, and Nb were studied in vitro in simulated body fluid (SBF) under static conditions. The release of ions and pH changes up to 7 days of immersion were investigated. The nitrogen incorporation into phosphate glass matrix was found to notably influence in vitro dissolution only of homogenous glasses. Increasing the nitrogen content in the samples...
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Terbium Substituted Lanthanum Orthoniobate: Electrical and Structural Properties
PublicationThe results of electrical conductivity studies, structural measurements and thermogravimetric analysis of La1−xTbxNbO4+δ (x = 0.00, 0.05, 0.1, 0.15, 0.2, 0.3) are presented and discussed. The phase transition temperatures, measured by high-temperature x-ray diffraction, were 480 °C, 500 °C, and 530 °C for La0.9Tb0.1NbO4+δ, La0.8Tb0.2NbO4+δ, and La0.7Tb0.3NbO4+δ, respectively. The impedance spectroscopy results suggest mixed conductivity...
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Salicylaldimine-based receptor as a material for iron(III) selective optical sensing
Publicationα,α-Bis(salicylimino)-m-xylene (L) was prepared using both conventional and microwave-assisted procedure. The compound exhibits ability to colorimetric recognition of iron(III) ions in aqueous environment, what is shown by significant color change from yellow to purple. In DMSO : water (9:1 v/v) solvent system receptor creates with iron(III) cations complexes of 2:1 stoichiometry (L:Fe3+) with stability constant (log K) 7.54±0.21....
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Microstructure and electrical properties of manganese borosilicate glasses
PublicationThe structure, optical and electrical properties of manganese borosilicate glasses of the composition xMnO–(80 − x)SiO 2 –20B 2 O 3 (x = 40, 50, and 60 mol%) were investigated. The dependence of the glass structure on its composition was discussed and related to electrical properties. A separation of two amorphous phases was observed. It was suggested that one phase is MnO-rich and the other is SiO 2 -rich. It was found that...
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SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF NIOBIUM-DOPED HYDROXYAPATITE CERAMICS
PublicationHydroxyapatite (HAp) ceramic materials are considered as one of the most promising implant materials in bone surgery and in dentistry. They exhibit unique biocompatibility, bioactivity, and osteoconductivity, which are the most desirable biomaterial features. However, HAp itself is brittle, has low strength, high degree of crystallinity and low solubility at physiological pH. Doping synthetic HAp with metal ions plays an important...
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Synthesis, crystal structure and spectroscopic characterization of new anionic iridium(III) complexes and their interaction with biological targets
PublicationThe synthesis and characterisation of new anionic iridium(II) complexes (NH4)2[IrCl4(κ2N,N’-H2biim)]2 · 5H2O (1) and ((CH3)2NH2)[IrCl4(κ2N,N’-PyBIm)] · H2O (2) are presented in this article. Spectroscopic methods (1H, 13C and 15N NMR, FTIR, UV-Vis) were used to characterize these new complexes. Solid-state structural analysis (SC-XRD) of complexes 1 and 2 shows a slightly distorted octahedral geometry of Ir(III) ions, which is...
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Ni-based compounds in multiwalled graphitic shell for electrocatalytic oxygen evolution reactions
Open Research DataThis study investigates Ni-based compounds (Ni, NiO, Ni3C) coated with a graphitic shell as electrocatalysts for the oxygen evolution reaction (OER). Electron paramagnetic resonance (EPR) and X-ray diffraction (XRD) are employed to identify the presence and contribution of Nickel ions (Ni0, Ni2+, Ni3+) and determine the phase composition. Electrochemical...
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The luminescence study of Sr2TiO4:Sm3+ coumpounds.
Open Research DataA luminescent material based on the strontium orthotitanate (Sr2TiO4) matrix doped with 1% of a mole of samarium was obtained using the typical solid-state synthesis method under a neutral atmosphere of nitrogen. The sample was investigated using powder X-ray diffraction (XRD) and several luminescence techniques to study the phase composition, luminescence...
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The Impact of Crushed Rock Spoil on Pitting Corrosion of Selected Stainless Steel
PublicationThe paper presents the results of the pitting resistance investigations of selected stainless steels in the chloride environment and the simultaneous impact of erosive factors using the cyclic polarization technique. Additionally, using electrochemical techniques, ie: electrochemical impedance spectroscopy (EIS) and measurement of corrosion potential, the behavior of the passive layer of selected stainless steels in the environment...
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The properties of reduced Bi-Ge-O glasses for thermoelectric devices
PublicationThe bismuth-germanate glasses have been investigated to examine their applicability for thermoelectric devices. In order to increase their electrical conductivity, the 25Bi2O3–75GeO2 glass samples have been reduced at 340-380°C for 10 hours in hydrogen. It has been shown that such heat treatment in H2 leads to the reduction of metal ions Bi3+ and Ge4+ into neutral atoms and the formation of metal grains both in an amorphous glass...
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Morphology and properties of nanotubular oxide layer on the Ti13Zr13Nb alloy
PublicationThe Ti13Zr13Nb alloy in solid and porous form was oxidised. The constant voltage 20 V, oxidation time 0.5 and 1 h, and 1 M H3PO4 (orthophosphoric acid) with addition of HF (hydrofluoric acid) as a test solution were applied. SEM (Scanning Electron Microscope) examinations of surface, EDS (Energy Dispersive X-ray Spectroscopy) chemical analysis, nanohardness and nano-scratch tests, and corrosion potentiokinetic tests at various...
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Novel Diazocrowns with Pyrrole Residue as Lead(II) Colorimetric Probes
PublicationNovel 18- and 23-membered diazomacrocycles were obtained with satisfactory yields by diazocoupling of aromatic diamines with pyrrole in reactions carried under high dilution conditions. X-ray structure of macrocycle bearing five carbon atoms linkage was determined and described. Compounds were characterized as chromogenic heavy metal ions receptors. Selective color and spectral response for lead(II) was found in acetonitrile and...
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Gas sensors based on conducting polymers-recent developments
PublicationThis work discusses sensing performance dependence of PEDOT polymer and its composites on the counter ions used in the polymerization process. The sensors based on PEDOT-RGO composite show reversible response to NO2, while on PEDOT/LiClO4 irreversible. As a result, PEDOT-RGO could be used as a typical gas sensor, while sensor based PEDOT/LiClO4 could be used as an integrating gas sensor, also known as an accumulating gas sensor....
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Solar light driven degradation of norfloxacin using as-synthesized Bi 3+ and Fe 2+ co-doped ZnO with the addition of HSO 5 – : Toxicities and degradation pathways investigation
PublicationIn this study, solar light responsive Bi3+ and Fe2+ doped ZnO were synthesized and used for photocatalytic degradation of norfloxacin (NOR), an emerging water pollutant. Analysis with Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron...
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An Easy and Ecological Method of Obtaining Hydrated and Non-Crystalline WO3−x for Application in Supercapacitors
PublicationIn this work, we report the synthesis of hydrated and non-crystalline WO3 flakes (WO3−x) via an environmentally friendly and facile water-based strategy. This method is described, in the literature, as exfoliation, however, based on the results obtained, we cannot say unequivocally that we have obtained an exfoliated material. Nevertheless, the proposed modification procedure clearly affects the morphology of WO3 and leads to loss...
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Ultrasonic spectroscopy of silicon single crystal
PublicationSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Yields and Time-of-Flight Spectra of Neutral High-Rydberg Fragments at the K Edges of the CO2 Molecule
PublicationWe have studied the production of neutral fragments in high-Rydberg (HR) states at the C 1s and O 1s edges of the CO2 molecule by performing two kinds of experiments. First, the yields of neutral HR fragments were measured indirectly by ionizing such fragments in a static electric field and by collecting resulting singly charged positive ions as a function of the photon energy. Such measurements reveal not only excitations below...
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Annual changes of basic parameters of bottom sediments from the Klodnica River Catchment
PublicationThe Klodnica River Catchment is heavily contaminated ecosystem located in area of the Upper Silesia Industrial Region. In this area various forms of human activity can be observed (e.g. mining coal underground, metallurgy, power/heat plants, wastewater discharged directly into the river). The impact of industrial and municipal wastes on this aquatic system causes to changes in the hydrographic network of river and the waters quality. In...
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Binuclear Co(II), Zn(II) and Cd(II) tri-tert-butoxysilanethiolates. Synthesis, crystal structure and spectroscopic studies.
PublicationA series of Co(II), Zn(II) and Cd(II) complexes have been synthesized in reaction of respective metal tri-tert-butoxysilanethiolates with pyrazine 1 and 2 and 1,2-bis(2-pyridyl)ethylene 3–5. All compounds have been characterized by single-crystal X-ray structure determination, elemental analysis, FT-IR and thermogravimetry. Obtained complexes are bimetallic with the formula of [M{SSi(OtBu)3}2(μ-L)]2 and metal ions bridged by N,N′-spacer....
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Bis-phosphonated carbon nanotubes: one pot synthesis and their application as efficient adsorbent of mercury
PublicationEffective, one-pot method of CNTs phosphonylation is presented. Cheap and readily available reagents are used, so the process can be easily transferred to large-scale production. The product was analyzed using spectroscopic methods (FTIR, UV-vis, XPS). Thermal properties of the bis-phosphonated nanotubes are reported for the first time. Newly obtained material was tested as an adsorbent for mercury removal from water. The sorption...
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Carnivorous plants used for green synthesis of silver nanoparticles with broad-spectrum antimicrobial activity
PublicationIn this study, we exploit the anti-oxidative potential of four carnivorous plants to produce uniform and biologically active silver nanoparticles. The use of polyvinylpyrrolidone promoted syn-thesis of quasi-spherical nanoparticles characterized by stability and high uniformity. Their activity was tested against three human pathogens and three species of plant pathogenic bacteria. The study demonstrates the influence of synthesis...
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Magnetizability of the relativistic hydrogenlike atom in an arbitrary discrete energy eigenstate: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationThe Sturmian expansion of the generalized Dirac--Coulomb Green function [R.\/~Szmytkowski, J.\ Phys.\ B 30 (1997) 825; erratum 30 (1997) 2747] is exploited to derive a closed-form expression for the magnetizability of an arbitrary discrete state of the relativistic one-electron atom with a point-like, spinless and motionless nucleus of charge $Ze$. The result has the form of a double finite sum involving the generalized hypergeometric...
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Nuclear magnetic shielding constants of Dirac one-electron atoms in some low-lying discrete energy eigenstates
PublicationWe present tabulated data for the nuclear magnetic shielding constants (σ) of the Dirac one-electron atoms with a pointlike, motionless and spinless nucleus of charge Ze. Utilizing the exact general analytical formula for σ derived by us (Stefańska, 2016) valid for an arbitrary discrete energy eigenstate, we have computed the numerical values of the magnetic shielding factors for the ground state and for the first and the second...
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Mixed ionic-electronic conductivity and structural properties of strontium-borate glass containing nanocrystallites of Bi2 VO5.5
PublicationSamples of strontium borate glass containing bismuth vanadate nanocrystallites were prepared. Nanocomposites containing up to 45mol% of the Bi2VO5.5 phase exhibit electrical properties closer to the strontium-borate glass than to the ferroelectric Bi2VO5.5 ceramic. The glass matrix still may contain some part of bismuth and vanadium ions even after crystallization process and there is too little of crystalline phase to observe...
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Stripe order and magnetic anisotropy in the S=1 antiferromagnet BaMoP2O8
PublicationMagnetic behavior of yavapaiite-type BaMoP2O8 with the spatially anisotropic triangular arrangement of the S=1Mo4+ ions is explored using thermodynamic measurements, neutron diffraction, and density-functional band-structure calculations. A broad maximum in the magnetic susceptibility around 46 K is followed by the stripe antiferromagnetic order with the propagation vector k=(12,12,12) formed below TN≃21 K. This stripe phase is...