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Search results for: fe2o3 nanocrystals
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In Situ Random Microseeding and Streak Seeding Used for Growth of Crystals of Cold-Adapted beta-D-Galactosidases: Crystal Structure of betaDG from Arthrobacter sp. 32cB
PublicationThere is an increasing demand for cold-adapted enzymes in a wide range of industrial branches. Nevertheless, structural information about them is still scarce. The knowledge of crystal structures is important to understand their mode of action and to design genetically engineered enzymes with enhanced activity. The most difficult task and the limiting step in structural studies of cold-adapted enzymes is their crystallization,...
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Quantum dots conjugates with unsymmetrical bisacridines enhance cytotoxicity of these antitumor compounds in lung cancer cells and have protecting effects on normal cells
PublicationBackground: In recent years, with the rapid development of nanotechnology and its extensive applications in the medicine, nanocarriers for anticancer drug delivery have gained a great importance. Spherical semiconductor nanocrystals, frequently called quantum dots (QDs) are very attractive nanomaterials for bioimaging applications and they possess properties as potential candidates for drug carrier. Unsymmetrical bisacridines (UAs),...
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TiO2-C nanocomposite synthesized via facile surfactant-assisted method as a part of less energy-consuming LED-based photocatalytic system for environmental applications
PublicationA novel facile method was used to incorporate carbon into the titania structure. An alternative synthesis method of carbon-doped TiO2 has been proposed by using a widely used and cheap surfactant. During the process, cetyltrimethylammonium bromide plays a dual role, as a morphology modifier and as a carbon source. The presented approach allows obtained TiO2-C nanostructures to be anatase nanocrystals with carbon being deposited...
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Fluctuation-enhanced and conductometric gas sensing with nanocrystalline NiO thin films: A comparison
PublicationNanocrystalline thin films of NiO were prepared by advanced reactive gas deposition, and their responses to formaldehyde, ethanol and methane gases were studied via fluctuation-enhanced and conductometric methods Thin films with thicknesses in the 200–1700-nm range were investigated in as-deposited form and after annealing at 400 and 500 °C. Morphological and structural analyses showed porous deposits with NiO nanocrystals having...
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Linear and nonlinear impedance in iron oxide glasses containing alkaline ions and alkali free
PublicationThe linear and nonlinear impedance spectra of oxide glasses were measured in the frequency range of 1 mHz to 1 MHz and in the temperature range of 153K to 483K. Two groups of iron oxide glass samples were prepared, the first one containing alkaline ions and the second one without alkali. In the first group, compositions of glasses were as follows: (in %mol) 50% SiO2 , 25% PbO, 15% Fe2O3 and 15% one of alkaline oxides: Na2O, K2O,...
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The influence of nanostructures size on V2O5 electrochemical properties as cathode materials for lithium ion battery
PublicationIn this paper, V2O5 nanostructures with a size depending on the annealing temperature are successfully synthesized by a sol-gel method. The crystal structure and morphology of samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), selected area electron diffraction (SEAD) and scanning electron microscopy (SEM), respectively. Electrochemical testing such...
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Chitin and derivative chitosan-based structures — Preparation strategies aided by deep eutectic solvents: A review
PublicationThe high molecular weight of chitin, as a biopolymer, challenges its extraction due to its insolubility in the solvents. Also, chitosan, as the N-deacetylated form of chitin, can be employed as a primary material for different industries. The low mechanical stability and poor plasticity of chitosan films, as a result of incompatible interaction between chitosan and the used solvent, have limited its industrialization. Deep eutectic...
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Immittance Studies of Bi6Fe2Ti3O18 Ceramics
PublicationResults of studies focusing on the electric behavior of Bi6Fe2Ti3O18 (BFTO) ceramics are reported. BFTO ceramics were fabricated by solid state reaction methods. The simple oxides Bi2O3, TiO2, and Fe2O3 were used as starting materials. Immittance spectroscopy was chosen as a method to characterize electric and dielectric properties of polycrystalline ceramics. The experimental data were measured in the frequency range D = (101–107)...
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High resolution X-ray diffractometry and reflectometry of semiconductor nano- and micro- structures based on X-ray refractive optics
PublicationIn this thesis proposed, discussed and studied novel synchrotron X-ray diffractometry and reflectometry methods based on a refractive optics. The experimental results obtained from the ID06 beamline at ESRF, Grenoble, France are presented and analyzed in this work to demonstrate a high angular and space resolution in addition to the opportunity to manage in situ and on operando experiments with the help of proposed X-ray optical...
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Iron doped manganese cobaltite spinel coatings produced by electrophoretic co-deposition on interconnects for solid oxide cells: Microstructural and electrical characterization
PublicationWe report a systematic microstructural and electrical characterization of iron doped Mn–Co spinel coatings processed by electrophoretic co-deposition of Mn1.5Co1.5O4 and Fe2O3 powders on Crofer 22 APU and AISI 441 steel substrates. Iron addition to Mn–Co spinel coating leads to a reduction of the area specific resistance on both substrates, after 3200 h at 750 °C. The Fe doped Mn–Co coating both leads to a thinner oxide scale and...
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Nanostructured biocatalysis for biotechnological applications
PublicationThe purpose immobilization process is to enhance the performance of an enzyme for commercial processes. A large number of structures have been reported in the literature to boost the effectiveness of immobilized enzymes. The nanomaterials have the optimal properties for equilibrating key parameters that govern the performance of biocatalysts, such as high enzyme loading ability, specific surface area, and mass transfer resistance....
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Enhancing electrical properties through in-situ controlled nanocrystallization of V2O5–TeO2 glass
PublicationV2O5–TeO2 glass–ceramics (VTGC) were prepared by controlled annealing of the V2O5–TeO2 glass (VTG), which illustrates a parent glass matrix with a single charge carrier. The annealing proceeded at six temperatures selected between the glass transition and the maximum of the frst crystallization process to obtain various nanocrystallite sizes. Heat treatment caused an increase in DC conductivity by 2.5–3.5 (250–285 °C) order of...
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Bis(ammonium) Zoledronate Dihydrate
PublicationNeutralization of 2-(1-imidazole)-1-hydroxyl-1,1`-ethylidenediphosphonic acid (zoledronic acid) by an excess of ammonia yielded bis(ammonium) zoledronate dihydrate, {C5H8N2O7P2 2−, 2(H4N+), 2(H2O)}. The product is readily soluble in water and forms monocrystals for which the X-ray structural analysis was carried out. The zoledronic anion is of double negative charge due to deprotonation of three P–OH groups and protonation of the...
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Magnetic photocatalysts for water treatment
PublicationThe concept of magnetic photocatalysts with separation function requires ferromagnetic material with high magnetic susceptibility to an external magnetic field to enable recycling of composite nanoparticles. Currently, much attention is devoted to functionalization of photocatalyst using MFe2O3, where M =Fe, Zn, Co, Mn. However direct contact between photocatalyst and magnetic iron oxide particles leads to photodissolution of iron...
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A new simple approach to prepare rare-earth metals-modified TiO2 nanotube arrays photoactive under visible light: Surface properties and mechanism investigation
PublicationApplication of Ti90RE10 alloys (RE = Ho, Er, Nd, Y, Ce, Tm) as a working electrode, instead of Ti pure foil in anodic oxidation in a fluoride-based electrolyte, resulted in formation of well-ordered nanotubes made of TiO2 and RE2O3 mixture, which could be efficiently used for pollutant removal from water and air phase upon UV and visible irradiation and easily separable from the reaction mixture to recycle. The as-prepared NTs...
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BADANIE PRZEWODNICTWA W SZKŁACH BORANOWYCH ZAWIERAJĄCYCH JONY METALU PRZEJŚCIOWEGO
PublicationWłaściwości elektryczne szkieł żelazowo - boranowo - ołowiowych zostały zbadane za pomocą metody spektroskopii impedancyjnej. Mechanizm przewodnictwa w szkłach tlenkowych zawierających jony żelaza może być wywołany hoppingiem małych polaronów. Celem niniejszej pracy było bliższe określenie zachodzącego w nich mechanizmu przewodnictwa. Wytworzono szkła o składzie dobranym na podstawie ich zakresu szklenia: xFe2O3 - (100 - x)(B2O3...
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Up-conversion white emission and other luminescence properties of a YAG:Yb2O3·Tm2O3·Ho2O3@SiO2 glass-nanocomposite
PublicationWe report on a glass-nanocomposite material consisting of yttrium aluminum garnet (Y3Al5O12, YAG) nanocrystals co-doped with Yb3+, Tm3+ and Ho3+ ions as well as entrapped into a SiO2 xerogel. This 94YAG·5Yb2O3·0.8Tm2O3·0.2Ho2O3@SiO2 (abbr. YAG:YbTmHo@SiO2) nanocomposite material has been prepared by sol–gel procedure. Its structure and morphology has been characterized by means of X-ray diffraction (XRD) and scanning electron microscope...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublicationThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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Thermochemistry of rare earth perovskites Na3xRE0.67−xTiO3 (RE = La, Ce)
PublicationHigh-temperature oxide melt solution calorimetry using sodium molybdate (3Na2O·4MoO3) solvent at 973 K was performed for the Na3xRE0.67−xTiO3 (RE = La, Ce) perovskite series. The enthalpies of formation of lanthanum perovskites from oxides (La2O3, Na2O, TiO2), are −107.25 ± 2.56, −93.83 ± 6.06, −80.68 ± 5.93, and −33.49 ± 4.26 kJ/mol and enthalpies of formation from elements are −1614.05 ± 5.37, −1596.44 ± 7.68, −1594.03 ± 7.58,...
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Structural and spectroscopic investigation of new luminescent hybrid materials based on calix[4]arene-tetracarboxylate and Ln 3+ ions (Ln = Gd, Tb or Eu)
PublicationLanthanide-calixarene hybrid materials are of particular interest due to the combination of the interesting properties of the ligand cavity-like structure and the luminescent features of lanthanides. The aim of this study was to synthesize and investigate the photophysical properties of Eu3+, Tb3+ and Gd3+ hybrids based on calix[4]arene-tetracarboxylate. The preparation of two structurally different...
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Analiza oddziaływań w kryształach związków zawierających w strukturze pierścień pirydynowy
PublicationMożliwość tworzenia się wiązań wodorowych jest kluczowym parametrem z punktu widzenia inżynierii kryształu, ponieważ wiązania wodorowe mają bezpośredni wpływ na strukturę oraz trwałość sieci krystalicznej. Głównym celem niniejszej rozprawy doktorskiej była analiza porównawcza wiązań wodorowych występujących w układach, zawierających w strukturze pierścień pirydynowy. Badane układy podzielono na: (1) układy ze związkami krzemosiarkowymi...
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Protective and Suppressing Electromagnetic Interference Properties of Epoxy Coatings Containing Nano-Sized NiZn Ferrites
PublicationNano-crystalline ferrites with the chemical formula NixZn(1−x)Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a co-precipitation method. The obtained ferrites were investigated by X-ray diffraction (XRD). The corrosion inhibiting behavior of nano-sized ferrites was tested using carbon steel samples and 10% aqueous ferrite extracts. Results were compared with previous data obtained for micro-sized ceramic ferrites....
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From structure to luminescence investigation of oxyfluoride transparent glasses and glass-ceramics doped with Eu3+/Dy3+ ions
PublicationGlasses and glass-ceramics with nominal composition 73 TeO2– 4BaO– 3Bi2O3–18SrF2-2RE2O3 (where RE = Eu, Dy) have been synthesized by conventional melt-quenching technique and subsequent heat treatment at 370 °C for 24 h in air atmosphere. Various Eu3+ to Dy3+ molar ratio have been applied to investigate luminescence properties in both glass and glass-ceramic matrices. Especially, white light emission through simultaneous excitation...
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Lanthanide co-doped TiO2: the effect of metal type and amount on surface properties and photocatalytic activity
PublicationPreparation of new rare earth metal-containing TiO2 nanocomposites (Nd3+/Er3+, Nd3+/Eu3+, Eu3+/Ho3+-TiO2) using sol–gel route and their photoactivity under visible and ultraviolet light is reported. The obtained photocatalysts were subsequently characterized by Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse-reflectance spectroscopy (DRS), luminescence spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction...
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Study of anticorrosion and microwave absprption properties of NiZn ferrite pigments
PublicationPurpose - The purpose of this paper is to report the electrochemical verification of anticorrosive properties of NiZn ferrites as pigments in protective coatings and evaluation of their microwave absorbing properties. Design/methodology/approach - Ferrites, represented by formula NixZn(1-x)Fe2O4, where x=0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a ceramic method. The samples of ferrites were examined by X-ray diffraction...
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Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
PublicationMonocrystals of dinuclear -1,4-bis(3-aminopropyl)piperazine-4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(-BAPP)], 1, and polynuclear catena-poly[[bis-(tri-tert-butoxysilanethiolato-S)cadmium(II)]--1,4-bis(3-aminopropyl)piperazine-2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(-BAPP)]n,2, with 1,4-bis(3-aminopropyl)piperazine (BAPP)...
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Solvent influence on the crystal structures of new cadmium tri-tert -butoxysilanethiolate complexes with 1,4-bis(3-aminopropyl)piperazine: luminescence and antifungal activity
PublicationMonocrystals of dinuclear 1,4-bis(3-aminopropyl)piperazine-�4N1,N10:N4,N40-bis[bis(tri-tert-butoxysilanethiolato-�S)cadmium(II)], [Cd2(C12H27O3SSi)4(C10-H24N4)] or [Cd2{SSi(OtBu)3}4(�-BAPP)], 1, and polynuclear catena-poly[[bis- (tri-tert-butoxysilanethiolato-�S)cadmium(II)]-�-1,4-bis(3-aminopropyl)piperazine-�2N10:N40], [Cd(C12H27O3SSi)2(C10H24N4)]n or [Cd{SSi(OtBu)3}2(�-BAPP)]n, 2, with 1,4-bis(3-aminopropyl)piperazine (BAPP)...