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Four-body recombination in organic bulk heterojunction solar cells: an alternative interpretation
PublikacjaWe demonstrate a new interpretation of the previously reported quadrimolecular recombination in organic bulk heterojunction solar cells. It is suggested that the recently described (Szmytkowski 2012 Phys. Status Solidi RRL 6 300) interaction between exciton and electron–hole Langevin bound pair formed across the donor–acceptor interface is a four-particle process. This is in opposition to the treatment of this effect as a three-particle...
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Effects of solution composition and electrophoretic deposition voltage on various properties of nanohydroxyapatite coatings on the Ti13Zr13Nb alloy
PublikacjaThe purpose of the research was to establish the influence of the solution composition and the electrophoretic deposition voltage on the coating homogeneity and thickness, nanohardness, adhesion, corrosion resistance and wettability. The Ti13Zr13Nb alloy was coated by the electrophoretic technique with hydroxyapatite in a solution containing 0.1, 0.2 or 0.5 g nanoHAp in 100 mL of suspension and at voltage 15, 30 or 50 V. The scanning...
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Ionosphere variability II: Advances in theory and modeling
PublikacjaThis paper aims to provide an overview on recent advances in ionospheric modeling capabilities, with the emphasis in the efforts relevant to electron density variability. The discussion spans a wide range of model formulations (e.g., from purely empirical to physics-based ones and data-driven approaches) seeking for advances or gaps with regard to present challenges. This discussion is further supported by consideration of the...
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MODELLING OF CONCRETE FRACTURE AT AGGREGATE LEVEL USING DEM BASED ON X-RAY mu CT IMAGES OF INTERNAL STRUCTURE
PublikacjaThe paper describes two-dimensional meso-scale numerical results of fracture in notched concrete beams under quasi-static three-point bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones (ITZs) and air voids. As a numerical approach, the discrete element method (DEM) was used. The concrete micro-structure in calculations was directly...
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Imaging of biological samples: crassula arborescens
Dane BadawczeOne of the tasks of modern botany is to describe the relationship between climatic conditions and other environmental factors and the anatomical structure and adaptation of species present in given geographic areas. The work [1] focuses on anatomical and morphological studies of leaves of plants from the coarse family. Species tested belong to leaf...
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Unraveling Luminescent Energy Transfer Pathways: Futuristic Approach of Miniature Shortwave Infrared Light-Emitting Diode Design
Dane BadawczePhosphor-converted shortwave infrared phosphor light-emitting diodes (pc-SWIR LEDs, 900–1700 nm) are promising next-generation portable light sources for spectroscopy, security, optical communication, and medical applications. A typical design strategy involves energy transfer from Cr3+ to Ni2+, and thus, energy transfer from Cr3+–Cr3+ pairs to Ni2+...
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Reduction of the strontium titanate doped by Ytrium ceramics observed by X-ray photoemission spectroscopy method
Dane BadawczeYtrium-doped strontium titanate (YSTF) ceramics materials were manufactured by three various methods: 1) standard solid-state reaction method from Y2O3 (Sigma Aldrich, 99,9%), TiO2 (Sigma Aldrich, 99%) and SrCO3 (Sigma Aldrich,98%), 2) Pechini method, 3) wet method.
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Dataset of non-isomorphic graphs of the coloring types (K4,K4;n), 1<n<R(4,4)
Dane BadawczeFor K4 graph, a coloring type (K4,K4;n) is such an edge coloring of the full Kn graph, which does not have the K4 subgraph in the first color (representing by no edges in the graph) or the K4 subgraph in the second color (representing by edges in the graph).The Ramsey number R(4,4) is the smallest natural number n such that for any edge coloring of...
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3D polypyrrole structures as a sensing material for glucose detection
PublikacjaIn this work, 3D polypyrrole (PPy) structures as material for glucose detection is proposed. Polypyrrole was electrochemically polymerized on platinum screen-printed electrode from an aqueous solution of lithium perchlorate and pyrrole. The growth mechanism of such PPy structures was studied by ex-situ scanning electron microscopy. Preliminary studies show that studied here PPy film is a good candidate as a sensing material for...
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Magnetic field effects in dye-sensitized solar cells controlled by different cell architecture
PublikacjaThe charge recombination and exciton dissociation are generally recognized as the basic electronic processes limiting the efficiency of photovoltaic devices. In this work, we propose a detailed mechanism of photocurrent generation in dye-sensitized solar cells (DSSCs) examined by magnetic field effect (MFE) technique. Here we demonstrate that the magnitude of the MFE on photocurrent in DSSCs can be controlled by the radius and...
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Optimization of Hydrogen - Evolving Photochemical Molecular Devices
PublikacjaA molecular photocatalyst consisting of a RuII photocenter, a tetrapyridophenazine bridging ligand, and a PtX2 (X=Cl or I) moiety as the catalytic center functions as a stable system for light-driven hydrogen production. The catalytic activity of this photochemical molecular device (PMD) is significantly enhanced by exchanging the terminal chlorides at the Pt center for iodide ligands. Ultrafast transient absorption spectroscopy...
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Characterization of magnesium doped lanthanum orthoniobate synthesized by molten salt route
PublikacjaMolten salt synthesis method has been used to prepare the single phase magnesium doped lanthanum orthoniobate. The phase composition has been checked by X-ray diffraction method and the microstructure studies have been performed by scanning electron microscopy. The high temperature properties of the material have been investigated by thermogravimetry and electrochemical impedance spectroscopy. A dependence between sample total...
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Single-step grown boron doped nanocrystalline diamond-carbon nanograss hybrid as an efficient supercapacitor electrode
PublikacjaDirect synthesis of nano-structured carbon hybrid consisting of vertically aligned carbon nanograss on top of boron-doped nanocrystalline diamond is demonstrated and the carbon hybrid is further applied as an electrode material for the fabrication of supercapacitor. The hybrid film combines the dual advantages of sp2 (carbon nanograss) and sp3 (nanocrystalline diamond) bonded carbon, possessing not only the excellent electrical...
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ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
PublikacjaPolycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure...
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EMI attenuation in a DC-DC buck converter using GaN HEMT
PublikacjaA dc-dc buck converter using gallium nitride (GaN) high electron mobility transistors (HEMT) is experimentally investigated at the discontinuous current mode (DCM) and at the triangular current mode (TCM) operation. The paper objective is to specify the power conversion efficiency and attenuation of common mode (CM) and differential mode (DM) noise voltage, measured at the line impedance stabilization network (LISN) for compared...
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The effect of preliminary creep-strain on material behavior under LCF tension/compression and pure torsion regimes
PublikacjaThis paper presents the results of experimental tests of monotonic tension and torsion, creep-rupture and preliminary creep at 200C and 300C, as well as low-cycle fatigue of 2024 T3511 aluminum alloy. The fatigue process was conducted at room temperature for uniaxial tension/compression and torsion. The as-received material and pre-deformed material were also investigated during creep at elevated temperature. Basic monotonic,...
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Characterization of CaTi0.9Fe0.1O3/La0.98Mg0.02NbO4 composite
PublikacjaA composite of CaTi0.9Fe0.1O3 and electrolyte material, i.e. magnesium doped La0.98Mg0.02NbO4 was prepared and studied. The phase content and the sample microstructure was examined by an X-ray diffraction method and scanning electron microscopy. EDS measurements were done both for composite samples and the diffusion couple. The electrical properties were studied by four terminal DC method. The Ahigh-temperature interaction between...
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Hybrid battery based on arylated carbon nanotubes and laccase
PublikacjaSingle-walled carbon nanotubes (SWCNT) were covalently modified with anthracene and anthraquinone and used for the construction of cathodes for biocatalytic reduction of dioxygen. The nanotubes with aromatic groups casted onto the electrode increased the working surface of the electrode and enabled efficient direct electron transfer (DET) between the enzyme and the electrode. The aryl groups enter the hydrophobic pocket of the...
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Nanoparticle-free tissue-mimicking phantoms with intrinsic scattering
PublikacjaWe present an alternative to the conventional approach, phantoms without scattering nanoparticles, where scattering is achieved by the material itself: spherical cavities trapped in a silicone matrix. We describe the properties and fabrication of novel optical phantoms based on a silicone elastomer polydimethylsiloxane (PDMS) and glycerol mixture. Optical properties (absorption coefficient µa, reduced scattering coefficient µs',...
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Collision-induced luminescence spectra of pyridine bombarded by 1000 eV He+ cations
PublikacjaHere we show collision-induced luminescence spectra measured for collisions of the He+cations with thearomatic six-membered ring of the pyridine molecule (C5H5N). Distinct emission bands due to the CH(A2Δ→X2Πr;B2Σ+→X2Πr;C2Σ+→X2Πr), CN(B2Σ+→X2Σ+), C2(d3Πg→a3Πu), and NH(A3Π→X3Σ−) transitions, aswell as atomic H, He, and C lines have been observed. Apart from the He atoms, all the emitters arise from thefragmentation of the pyridine...
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Preliminary Investigation on Auto-Thermal Extrusion of Ground Tire Rubber
PublikacjaGround tire rubber (GTR) was processed using an auto-thermal extrusion as a prerequisite to green reclaiming of waste rubbers. The reclaimed GTR underwent a series of tests: thermogravimetric analysis combined with Fourier-transform infrared spectroscopy (TGA-FTIR), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and static headspace and gas chromatography-mass spectrometry (SHS-GC-MS) in order...
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Excited state properties of a series of molecular photocatalysts investigated by time dependent density functional theory.
PublikacjaTime dependent density functional theory calculations are applied on a series of molecular photocatalysts of the type [(tbbpy)2M1(tpphz)M2X2]2+ (M1 = Ru, Os; M2 = Pd, Pt; X = Cl, I) in order to provide information concerning the photochemistry occurring upon excitation of the compounds in the visible region. To this aim, the energies, oscillator strengths and orbital characters of the singlet and triplet excited states are investigated....
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Double ZIF-L structures with exceptional CO2 capacity
PublikacjaCarbon dioxide emission is an emerging problem nowadays and new methods are designed for its control. In this article, a report on the formation of zeolitic imidazole framework with an apparent double leaf-like morphology DZIF-L is given. The special structure of the materials prevents from aggregation of the particles providing remarkable CO2 capacity. At 0.1 MPa the CO2 uptake was 2.99 ± 0.06 mmol/g. The capacity of synthesized...
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Morphology and properties of nanotubular oxide layer on the Ti13Zr13Nb alloy
PublikacjaThe 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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Nitrogen-Doped Diamond Film for Optical Investigation of Hemoglobin Concentration
PublikacjaIn this work we present the fabrication and characterization of a diamond film which can be utilized in the construction of optical sensors for the investigation of biological samples. We produced a nitrogen-doped diamond (NDD) film using a microwave plasma enhanced chemical vapor deposition (MWPECVD) system. The NDD film was investigated with the use of scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman...
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Structural and mechanical properties of hydroxyapatite coatings formed by ion-beam assisted deposition
PublikacjaThe ion-beam assisted deposition (IBAD) is an advanced method capable of producing crystalline coatings at low temperatures. We determined the characteristics of hydroxyapatite Ca10(PO4)6(OH)2 target and coatings formed by IBAD using X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray (EDX). The composition of the coatings'...
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Failure of austenitic stainless steel tubes during steam generator operation
PublikacjaThe article presents the failure process of austenitic stainless steels used in power devices, such as heat exchangers, steam generators, in terms of local corrosion: pitting, stress and intergranular corrosion, paying particular attention to welded joints area. The effect of steel chemical composition, microstructure, welding process and work environment was analyzed. The second part of the article presents the results of the...
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Biological and mechanical research of titanium implants covered with bactericidal coating
PublikacjaThe paper concerns the biological and mechanical properties of titanium implants with an antibacterial coating. The Ti13Zr13Nb alloy samples were coated with hydroxyapatite (HAp) coatings using the electrophoretic deposition technique (EPD). Subsequently, the surface of the samples was modified with silver, copper, and nickel nanoparticles by the immersion method. Different titanium sample types (i.e. HAp-only and nanometals-enriched...
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New approach for the synthesis of Ag3PO4-graphene photocatalysts
PublikacjaA facile and effective plasma sputtering method for the preparation of a visible light active photocatalyst - rhombic dodecahedral silver phosphate Ag3PO4 covered with nanographene (Ag3PO4-GR) with improved stability has been developed. Proposed method allows for the usage of readily available materials for nanographene sputtering and for easy scaling-up. The stability improvement, confirmed by visible light-induced phenol degradation...
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Micro-cracking pattern recognition of hybrid CNTs/GNPs cement pastes under three-point bending loading using acoustic emission technique
PublikacjaThe generation of microcracks has an important influence on the behaviour of concrete structures. In this study, the acoustic emission (AE) technique was used to investigate the fracture phenomena and micro-cracking behavior of hybrid carbon nanotubes (CNTs, the 1-D allotrope of carbon atoms) and graphene nanoplatelets (GNPs, 2D monolayer of sp2-hybridized carbon atoms), cement composites under three-point bending loading. In...
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Release systems based on self-assembling RADA16-I hydrogels with a signal sequence which improves wound healing processes
PublikacjaSelf-assembling peptides can be used for the regeneration of severely damaged skin. They can act as scaffolds for skin cells and as a reservoir of active compounds, to accelerate scarless wound healing. To overcome repeated administration of peptides which accelerate healing, we report development of three new peptide biomaterials based on the RADA16-I hydrogel functionalized with a sequence (AAPV) cleaved by human neutrophil elastase...
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in -60°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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XPS data of deuterium and hydrogen grown boron-doped diamond
Dane BadawczeThe high-resolution C1s X-ray absorption spectra of BDD@H and BDD@D samples were measured using the facilities of the HE-SGM beamline (HE-SGM) at the BESSY II synchrotron radiation source of Helmholtz–Zentrum Berlin (HZB).[90] The measurements were carried out under ultra-high vacuum conditions: P ≈ 2×10−9 Torr at T = 300 K. The NEXAFS spectra were...
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in +20°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in -40°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in -50°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in 0°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Mechanical properties of VL E27 steel for shipbuilding –SEM fracture investigation (Charpy test in -20°C)
Dane BadawczeOne of the basic divisions of steels used for ship hulls and ocean engineering structures is the division into: normal strength steels, high strength steels and extra high strength steels. The belonging to the group is determined by the mechanical properties of the steel, such as: yield point, ultimate strength and plastic elongation after fracture....
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Sulfammox process_task 1
Dane BadawczeAnaerobic ammonia-oxidizing bacteria have a more comprehensive metabolism thanexpected - there may be other electron acceptors that oxidize ammonium nitrogen under anaerobicconditions, in addition to the well-known nitrite nitrogen, one of which is sulfate in the sulfammoxprocess. Sulfate-containing compounds are part of the medium for the anammox process,...
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Magnetyczne właściwości nanostruktur i spintronika 23/24
Kursy OnlineStudent poznaje materiały o właściwościach magnetycznych oraz prawa opisujące właściwości magnetyczne materiałów w skali makro, mikro i w skali nano. Student poznaje w szczególności metody badań tych właściwości oraz zasady wykorzystania materiałów magnetycznych w nauce i w technice. Student poznaje też zagadnienia dotyczące spintroniki w zakresie metod oddziaływania na spin i wykorzystywania tych metod dla wykorzystywania spinów...
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Do positrons measure atomic and molecular diameters?
PublikacjaWe report on density functional calculations (DFT) of elastic integral scattering cross-sections for positron collisions with argon, krypton, nitrogen and methane. The long-range asymptotic polarization potential is described using higher-order terms going much beyond an induced dipole potential (−α / r 4) while the short-range interaction is modeled by two different forms of electron – positron correlation potential (Boroński-Nieminen...
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APPLICATION OF MAGNETIC NANOPARTICLES FOR WATER TREATMENT
PublikacjaIn this study magnetic nanoparticles were fabricated and used for water treatment. Nanoparticles were prepared in two ways. The first one involved NiZn ferrite nanoparticles synthesized by co-precipitation of metal cations with sodium hydroxide at high temperature. The second one featured maghemite nanoparticles was prepared by saltassisted solid-state reaction. Modification and functionalization of nanoparticles surface was investigated....
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The determinants of morphology and properties of the nanohydroxyapatite coating deposited on the Ti13Zr13Nb alloy by electrophoretic techniqe
PublikacjaThe titanium and its alloys belong at present to the most preferred and commonly applied biomaterials for load- bearing implants. The surfaces of biomaterials are subjected to modification, including the hydroxyapatite coatings deposited in order to ensure corrosion resistance and better joining between an implant and a bone through the possibility of ingrowth bone into the coating. In this paper, the morphology and properties...
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Synthesis, single crystal growth and properties of Sr5Pb3ZnO12
PublikacjaAbstract The novel Sr5Pb3ZnO12 oxide was synthesized by the solid-state reaction method. The crystal structure was studied by means of the powder x-ray diffraction Rietveld method and was found to be similar to 3 other previously known Sr5Pb3MO12 compounds (M = Co, Ni, Cu). Crystals of several hundred microns in size of the new phase were grown in molten sodium chloride and imaged using confocal optical and scanning electron microscopy....
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Influence of electropolymerization conditions on the morphological and electrical properties of PEDOT film
PublikacjaIn this work the effects of electropolymerization conditions on the morphological properties and conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) film have been studied. PEDOT films were electrochemically synthesized in a one step process from acetonitrile solution containing 3,4-ethylenedioxythiophene (EDOT) and lithium perchlorate. Based on atomic force microscopy, scanning electron microscopy, cyclic voltammetry and...
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The influence of thermal conditions on V2O5 nanostructures prepared by sol-gel method
PublikacjaThis work presents the result of structure investigations ofV 2O5 nanorods grown from thin films and powders prepared by sol-gel method. To examine the best temperature of nanorods crystallization, thin films deposited by spin-coating method on quartz glass or silicon substrates and bulk xerogel powders were annealed at various temperatures ranging from 100∘C to 600∘C. The structure of the samples was characterized by X-ray diffraction...
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Evidence for solid state electrochemical degradation within a small molecule OLED
PublikacjaAcridone 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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Meldrum’s acid assisted formation of tetrahydroquinolin‑2‑one derivatives a short synthetic pathway to the biologically useful scaffold
PublikacjaA new method for the preparation of tetrahydroquinolin-2-one derivatives is presented. This approach involves a two-step reaction between enaminones and acylating agents, immediately followed by electrophilic cyclization, all within a single synthesis procedure, eliminating the need to isolate intermediates. The entire process is facilitated by the use of acyl Meldrum’s acids which not only shortens the preparation time of the...
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Experimental and numerical studies on the mechanical response of a piezoelectric nanocomposite-based functionally graded materials
PublikacjaThis work presents an experimental study of piezoelectric structures reinforced by graphene platelets, based on the concept of the functionally graded materials (FGMs). The assumed model is a rectangular beam/plate and the composition is due to the Halpin-Tsai rule. The model is also simulated in the Abaqus software which is the first time that such a structure has been modelled in an FEM package. In addition, a mathematical model...
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Charge-based deep level transient spectroscopy of B-doped and undoped polycrystalline diamond films
PublikacjaThe undoped and B-doped polycrystalline diamond thin film was synthesized by hot filament chemical vapor deposition and microwave plasma, respectively. The structural characterization was performed by scanning electron microscopy, X-ray diffraction and Raman spectroscopy. The electrical properties of synthesized diamond layer were characterized by dc-conductivity method and charge deep level transient spectroscopy. The B-doped...