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Search results for: ultrasound-assisted microextraction
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Do the young employees perceive themselves as digitally competent and does it matter?
PublicationPurpose – The study aims to examine the digital competence of young employees (under 30 years of age) who graduated from the technical university. Self-assessment of selected digital competencies was examined along with the determination of a self-efficacy level in the area of using digital competencies. Design/methodology/approach – Quantitative research was conducted using the computer-assisted web interview method on a sample...
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The role of hydrogen bonding on tuning hard-soft segments in bio-based thermoplastic poly(ether-urethane)s
PublicationThis work describes the preparation of bio-based thermoplastic poly(ether-urethane)s (TPU) via a prepolymer method and investigates the effect of varying the interphase hydrogen-bonding (H-bonding) on physicochemical, thermal and mechanical properties. This was achieved by varying the glycol type and molar ratio of [NCO]/[OH] groups used during the prepolymer chain extending step. The TPUs’ chemical structure was analyzed by Fourier...
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Bioactive hybrid metal-organic framework (MOF)-based nanosensors for optical detection of recombinant SARS-CoV-2 spike antigen
PublicationFast, efficient, and accurate detection of SARS-CoV-2 spike antigen is pivotal to control the spread and reduce themortality of COVID-19. Nevertheless, the sensitivity of available nanobiosensors to detect recombinant SARS-CoV-2 spike antigen seems insufficient. As a proof-of-concept, MOF-5/CoNi2S4 is developed as a low-cost, safe, and bioactive hybrid nanostructure via the one-pot high-gravity protocol. Then, the porphyrin, H2TMP,...
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Fatty acyl benzamido antibacterials based on inhibition of DnaK-catalyzed protein folding
PublicationWe have reported that the hsp70 chaperone DnaK from Escherichia coli might assist protein folding by catalyzing the cis/trans isomerization of secondary amide peptide bonds in unfolded or partially folded proteins. In this study a series of fatty acylated benzamido inhibitors of the cis/trans isomerase activity of DnaK was developed and tested for antibacterial effects in E. coli MC4100 cells. Nα-[Tetradecanoyl-(4-aminomethylbenzoyl)]-l-asparagine...
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The Product of Matrix Metalloproteinase Cleavage of Doxorubicin Conjugate for Anticancer Drug Delivery: Calorimetric, Spectroscopic, and Molecular Dynamics Studies on Peptide–Doxorubicin Binding to DNA
PublicationMatrix metalloproteinases (MMPs) are extracellular matrix degradation factors, promoting cancer progression. Hence, they could provide an enzyme-assisted delivery of doxorubicin (DOX) in cancer treatment. In the current study, the intercalation process of DOX and tetrapeptide-DOX, the product of the MMPs' cleavage of carrier-linked DOX, into dsDNA was investigated using stationary and time-resolved fluorescence spectroscopy, UV-Vis...
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Reduced-cost electromagnetic-driven optimisation of antenna structures by means of trust-region gradient-search with sparse Jacobian updates
PublicationNumerical optimisation plays more and more important role in the antenna design. Because of lack of design-ready theoretical models, electromagnetic (EM)-simulation-driven adjustment of geometry parameters is a necessary step of the design process. At the same time, traditional parameter sweeping cannot handle complex topologies and large number of design variables. On the other hand, high computational cost of the conventional...
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Accelerated multi-objective design of miniaturized microwave components by means of nested kriging surrogates
PublicationDesign of microwave components is an inherently multiobjective task. Often, the objectives are at least partially conflicting and the designer has to work out a suitable compromise. In practice, generating the best possible trade‐off designs requires multiobjective optimization, which is a computationally demanding task. If the structure of interest is evaluated through full‐wave electromagnetic (EM) analysis, the employment of...
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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublicationDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Studies on the solid-liquid equilibria and intermolecular interactions Urea binary mixtures with Sulfanilamide and Sulfacetamide
PublicationThe binary phase diagrams of Sulfanilamide-Urea (SN-U) and Sulfacetamide-Urea (SC-U) were measured using differential scanning calorimetry technique (DSC). Both examined mixtures were found to form simple binary eutectics. The limited miscibility in the solid state observed by DSC, proving inability of co-crystallization in new multi-molecular form, was also confirmed using PXRD and FTIR-ATR measurements of solid dispersions...
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Variable-Fidelity Simulation Models and Sparse Gradient Updates for Cost-Efficient Optimization of Compact Antenna Input Characteristics
PublicationDesign of antennas for the Internet of Things (IoT) applications requires taking into account several performance figures, both electrical (e.g., impedance matching) and field (gain, radiation pattern), but also physical constraints, primarily concerning size limitation. Fulfillment of stringent specifications necessitates the development of topologically complex structures described by a large number of geometry parameters that...
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Development of novel optoelectronic sensory structures utilising colour centres in nanodiamonds and their interactions with analytes
PublicationThe goal of this dissertation was to develop and assess surface modifications of fluorescent nanodiamonds (NDs) for optical sensing. Three modification routes were tested, each aimed at a different application. Modification with poly-L-lysine (pLys) was verified for optical sensing of pH via an interrelationship between electrically negative (NV¯) and neutral (NV0) nitrogen-vacancy centres. Immobilisation of Ochratoxin A (OTA),...
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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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Environmentally Friendly Fabrication of High-Efficient Fe-ZnO/Citric Acid-Modified Cellulose Composite and the Enhancement of Photocatalytic Activity in the Presence of H2O2
PublicationIn the present study, a novel Fe-ZnO/citric acid-modified cellulose composite (x%Fe-ZnOy% CAC) was synthesized using an environmentally friendly hydrothermal method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV−vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), nitrogen physisorption, and electrochemical and photocurrent density...
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Driving forces of informal employment: An empirical study based on Polish enterprise data
PublicationObjective: The article aims to indicate the determinants of informal employment in registered enterprises using company-level evidence from Poland. Research Design & Methods: The survey conducted among Polish small and medium-sized (SME) enterprises in 2018 was used to find the driving forces of informal employment in Poland. The adequate sample comprised 952 representative surveys derived from the computer-assisted telephone...
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Amperometric sensing of chemical oxygen demand at glassy carbon and silicon electrodes modified with boron-doped diamond
Publication.A boron-doped diamond (BDD) sensor is proposed for effective detection of chemical oxygen demand (COD) by means of amperometric technique. Boron-doped diamond thin films, acting as active sensors, were deposited on both silicon wafer and glassy carbon (GC) substrates by microwave plasma assisted chemical vapour deposition. SEM micrographs showed that BDD–Si displays triangle-faceted crystallites ca. 0.5–3 μm in size, while BDD–GC...
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Formaldehyde detection with chemical gas sensors based on WO3 nanowires decorated with metal nanoparticles under dark conditions and UV light irradiation
PublicationWe report results of formaldehyde gas (CH2O) detection under dark conditions and UV light irradiation with pristine tungsten trioxide nanowires (WO3 NWs) and metal nanoparticles decorated WO3 NWs gas sensing layers. The resistive layers were deposited by one step aerosol assisted chemical vapor deposition (AACVD) on commercial alumina substrates with 10-pair interdigitated platinum electrodes. The elaborated gas sensors, based...
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Expedited Variable-Resolution Surrogate Modeling of Miniaturized Microwave Passives in Confined Domains
PublicationDesign of miniaturized microwave components is largely based on computational models, primarily, full-wave electromagnetic (EM) simulations. EM analysis is capable of giving an accurate account for cross-coupling effects, substrate and radiation losses, or interactions with environmental components (e.g., connectors). Unfortunately, direct execution of EM-based design tasks such as parametric optimization or uncertainty quantification,...
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Boron-doped carbon nanowalls for fast and direct detection of cytochrome C and ricin by matrix-free laser desorption/ionization mass spectrometry
PublicationDetecting proteins via surface assisted laser desorption/ionization mass spectrometry (SALDI-MS) method is still highly challenging, and only few examples of nanomaterials have been demonstrated to perform such detection so far. In this study, carbon nanowalls (CNWs), vertically aligned graphene sheet-based materials, presenting specific morphology, dimensions, and boron doping levels have shown improved performances for both qualitative...
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Checkpoints that regulate balanced biosynthesis of lipopolysaccharide and its essentiality in Escherichia coli
PublicationThe outer membrane (OM) of Gram-negative bacteria, such as Escherichia coli, is essential for their viability. Lipopolysaccharide (LPS) constitutes the major component of OM, providing the permeability barrier, and a tight balance exists between LPS and phospholipids amounts as both of these essential components use a common metabolic precursor. Hence, checkpoints are in place, right from the regulation of the first committed step...
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Catalytic Mechanism of Non-Target DNA Cleavage in CRISPR-Cas9 Revealed by Ab Initio Molecular Dynamics
PublicationCRISPR-Cas9 is a cutting-edge genome editing technology, which uses the endonuclease Cas9 to introduce mutations at desired sites of the genome. This revolutionary tool is promising to treat a myriad of human genetic diseases. Nevertheless, the molecular basis of DNA cleavage, which is a fundamental step for genome editing, has not been established. Here, quantum–classical molecular dynamics (MD) and free energy methods are used...
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Fabrication and photoactivity of ionic liquid–TiO2 structures for efficient visible-light-induced photocatalytic decomposition of organic pollutants in aqueous phase
PublicationTo investigate the effect of the ionic liquid (IL) chain length on the surface properties and photoactivity of TiO2, a series of TiO2 microspheres have been synthesized via a solvothermal method assisted by 1-methyl-3-octadecylimidazolium chloride ([ODMIM][Cl]) and 1-methyl-3-tetradecylimidazolium chloride ([TDMIM][Cl]). All as-prepared samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy...
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Optimized photodegradation of palm oil agroindustry waste effluent using multivalent manganese–modified black titanium dioxide
PublicationThis article presents a methodological approach to use manganese (Mn3+Mn7+)-modified black titanium dioxide (Mn/BTiO2) as a photocatalyst to optimize and improve visible-light-driven photodegradation of treated agro-industrial effluent (TPOME). A modified wet chemical process was used to prepare BTiO2. The BTiO2 was then wet impregnated with Mn and calcined at 300 °C for 1 h to produce Mn/BTiO2. The activity of Mn/BTiO2 was investigated...
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Increased inspiratory resistance affects the dynamic relationship between blood pressure changes and subarachnoid space width oscillations
PublicationBackground and objective Respiration is known to affect cerebrospinal fluid (CSF) movement. We hypothesised that increased inspiratory resistance would affect the dynamic relationship between blood pressure (BP) changes and subarachnoid space width (SAS) oscillations. Methods Experiments were performed in a group of 20 healthy volunteers undergoing controlled intermittent Mueller Manoeuvres (the key characteristic of the procedure...
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Wavelet transform analysis to assess oscillations in pial artery pulsation at the human cardiac frequency
PublicationPial artery adjustments to changes in blood pressure (BP)may last only seconds in humans. Using a novelmethod called near-infrared transillumination backscattering sounding (NIR-T/BSS) that allows for the non-invasive measurement of pial artery pulsation (cc-TQ) in humans, we aimed to assess the relationship between spontaneous oscillations in BP and cc-TQ at frequencies between 0.5 Hz and 5 Hz. We hypothesized that analysis of...
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Exposure to Bisphenol A Analogs and the Thyroid Function and Volume in Women of Reproductive Age—Cross-Sectional Study
PublicationBisphenols (BPs) are commonly known plastifiers that are widely used in industry. The knowledge about the impact of BPs on thyroid function is scarce. Proper thyroid functioning is especially important for women of reproductive age, as hypothyroidism affects fertility, pregnancy outcomes and the offspring. There are no studies analyzing the influence of BPs on thyroid function and volume in non-pregnant young women. The aim of...
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CE-MS and GC-MS as “Green” and Complementary Methods for the Analysis of Biogenic Amines in Wine
PublicationTwo novel complementary analytical methods, namely an extraction-free capillary electrophoresis coupled to mass spectrometry (CE-MS) and direct immersion-solid-phase microextraction combined with gas chromatography-mass spectrometry (DI-SPME-GC-MS), have been developed and successfully applied for the determination of biogenic amines (BAs) in wine and fruit wine. They have been rigorously compared to each other in terms of various...
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Enhanced capacitance of composite TiO2 nanotube / boron-doped diamond electrodes studied by impedance spectroscopy
PublicationWe report on the novel composite nanostructures based on boron-doped diamond thin film grown on top of TiO2 nanotubes. The nanostructures made of BDD-modified titania nanotubes showed an increase in activity and performance when used as electrodes in electrochemical environments. The BDD thin films (~200-500 nm) were deposited using microwave plasma assisted chemical vapor deposition (MW PA CVD) onto anodically fabricated TiO2...
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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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Shape-dependent enhanced photocatalytic effect under visible light of Ag3PO4 particles
PublicationSilver phosphate (Ag3PO4) could be considered as visible light induced photocatalyst for pollutants degradation, due to its narrow band gap (∼2.4 eV). However, Ag3PO4 photoactivity depends on surface properties and synthesis route. In this study, differently shaped Ag3PO4 photocatalysts have been synthesized through the precipitation, ion exchange, soft-chemical or hydrothermal method. To correlate surface properties with photoactivity all...
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Salt melt synthesis of curved nitrogen-doped carbon nanostructures: ORR kinetics boost
PublicationImplementing metal-free electrocatalysts for the oxygen reduction reaction (ORR) and revealing crucial chemical or topographical parameters driving their activity are vital for the development of power cells. The carbon-based catalysts are very often synthesized through carbonization of biopolymers, in particular, those one containing nitrogen groups such as chitosan. Unfortunately, the resulting carbonaceous materials usually...
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Opto-Electrochemical Sensing Device Based on Long-Period Grating Coated with Boron-Doped Diamond Thin Film
PublicationThe fabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrodes on fused silica single mode optical fiber cladding has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ºC. We have obtained homogenous, continuous and polycrystalline surface morphology with high sp3 content in B-NCD...
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Nano-particle doped hydroxyapatite material evaluation using Spectroscopic Polarization Sensitive Optical Coherence Tomography
PublicationBio-ceramics such as hydroxyapatite (HAp) are widely used materials in medical applications, especially as an interface between implants and living tissues. There are many ways of creating structures from HAp like electrochemical assisted deposition, biomimetic, electrophoresis, pulsed laser deposition or sol-gel processing. Our research is based on analyzing the parameters of the sol-gel method for creating thin layers of HAp....
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Nanocrystalline diamond microelectrode on fused silica optical fibers for electrochemical and optical sensing
PublicationFabrication process of thin boron-doped nanocrystalline diamond (B-NCD) microelectrode on fused silica single mode optical fiber has been investigated. The B-NCD films were deposited on the fibers using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) at glass substrate temperature of 475 ºC. We have obtained homogenous, continuous and polycrystalline surface morphology with the mean grain size in the range of 100-250...
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Diamond-based protective layer for optical biosensors
PublicationOptical biosensors have become a powerful alternative to the conventional ways of measurement owing to their great properties, such as high sensitivity, high dynamic range, cost effectiveness and small size. Choice of an optical biosensor's materials is an important factor and impacts the quality of the obtained spectra. Examined biological objects are placed on a cover layer which may react with samples in a chemical, biological...
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Management of ground tire rubber waste by incorporation into polyurethane-based composite foams
PublicationRapid economic growth implicated the developing multiple industry sectors, including the automotive branch, increasing waste generation since recycling and utilization methods have not been established simultaneously. A very severe threat is the generation of enormous amounts of post-consumer tires considered burdensome waste, e.g., due to the substantial emissions of volatile organic compounds (VOCs). Therefore, it is essential...
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Topological-numerical analysis of a two-dimensional discrete neuron model
PublicationWe conduct computer-assisted analysis of a two-dimensional model of a neuron introduced by Chialvo in 1995 [Chaos, Solitons Fractals 5, 461–479]. We apply the method of rigorous analysis of global dynamics based on a set-oriented topological approach, introduced by Arai et al. in 2009 [SIAM J. Appl. Dyn. Syst. 8, 757–789] and improved and expanded afterward. Additionally, we introduce a new algorithm to analyze the return times...
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Photocatalytic activity of zinc oxide nanorods incorporated graphitic carbon nitride catalyst
PublicationBackground Photocatalysts are user-friendly and serve as compatible materials for degrading industrial dye pollutants. This study utilizes zinc oxide/graphitic carbon nitride (ZnO/g-C3N4) nanocomposites against degrading methylene blue (MB). Methods The hydrothermal method assisted sonication technique was used to fabricate the ZnO/g-C3N4 composite with varying ratios of ZnO/g-C3N4 (1:0.25, 1:0.50, 1:1). The synthesized materials...
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Machine-Learning-Based Global Optimization of Microwave Passives with Variable-Fidelity EM Models and Response Features
PublicationMaximizing microwave passive component performance demands precise parameter tuning, particularly as modern circuits grow increasingly intricate. Yet, achieving this often requires a comprehensive approach due to their complex geometries and miniaturized structures. However, the computational burden of optimizing these components via full-wave electromagnetic (EM) simulations is substantial. EM analysis remains crucial for circuit...
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Low-Cost Yield-Driven Design of Antenna Structures Using Response-Variability Essential Directions and Parameter Space Reduction
PublicationQuantifying the effects of fabrication tolerances and uncertainties of other types is fundamental to improve antenna design immunity to limited accuracy of manufacturing procedures and technological spread of material parameters. This is of paramount importance especially for antenna design in the industrial context. Degradation of electrical and field properties due to geometry parameter deviations often manifests itself as, e.g.,...
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On Fast Multi-objective Optimization of Antenna Structures Using Pareto Front Triangulation and Inverse Surrogates
PublicationDesign of contemporary antenna systems is a challenging endeavor, where conceptual developments and initial parametric studies, interleaved with topology evolution, are followed by a meticulous adjustment of the structure dimensions. The latter is necessary to boost the antenna performance as much as possible, and often requires handling several and often conflicting objectives, pertinent to both electrical and field properties...
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Constrained multi-objective optimization of compact microwave circuits by design triangulation and pareto front interpolation
PublicationDevelopment of microwave components is an inherently multi-objective task. This is especially pertinent to the design closure stage, i.e., final adjustment of geometry and/or material parameters carried out to improve the electrical performance of the system. The design goals are often conflicting so that the improvement of one normally leads to a degradation of others. Compact microwave passives constitute a representative case:...
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How thermal stability of ionic liquids leads to more efficient TiO2-based nanophotocatalysts: Theoretical and experimental studies
PublicationIonic liquids (ILs) containing distinct nitrogen-bearing organic cations (pyridinium, pyrrolidinium, imidazolium, ammonium, morpholinium) were first used for the preparation of 23 IL-TiO2 types of composites by ionic liquid assisted solvothermal synthesis. These 23 optimal ILs structures (i.e. compounds exhibiting an optimal combination of specific properties, functionality, and safety) for synthesis and experimental validation...
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UV-Vis-Induced Degradation of Phenol over Magnetic Photocatalysts Modified with Pt, Pd, Cu and Au Nanoparticles
PublicationThe combination of TiO2 photocatalyst and magnetic oxide nanoparticles enhances the separation and recoverable properties of nanosized TiO2 photocatalyst. Metal-modified (Me = Pd, Au, Pt, Cu) TiO2/SiO2@Fe3O4 nanocomposites were prepared by an ultrasonic-assisted sol-gel method. All prepared samples were characterized by X-ray powder diffraction (XRD) analysis, Brunauer-Emmett-Teller (BET) method, X-ray photoelectron spectroscopy...
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Towards Resource Theory of Coherence in Distributed Scenarios
PublicationThe search for a simple description of fundamental physical processes is an important part of quantum theory. One example for such an abstraction can be found in the distance lab paradigm: if two separated parties are connected via a classical channel, it is notoriously difficult to characterize all possible operations these parties can perform. This class of operations is widely known as local operations and classical communication....
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Ekstrakcja do fazy stałej niejedno ma imię
PublicationW czasach, gdy we wszystkich przejawach aktywności człowieka trzeba się odnieść do przesłanek leżących u podstaw zrównoważonego rozwoju trudno jest uzasadnić stosowanie w praktyce analitycznej takich procedur i operacji, które pociągają za sobą konieczność:użycia dużych ilości rozpuszczalników i odczynników chemicznychdużych nakładów energii czy też przyczyniają się do wzrostu ekspozycji pracowników laboratoriów na niekorzystne...
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Chemical Derivatization Processes Applied to Amine Determination in Samples of Different Matrix Composition
PublicationAmines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve...
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Improved surface coverage of an optical fibre with nanocrystalline diamond by the application of dip-coating seeding
PublicationGrowth processes of diamond thin films on the fused silica optical fibres (10 cm in length) were investigated at various temperatures. Fused silica pre-treatment by dip-coating in a dispersion consisting of detonation nanodiamond (DND) in dimethyl sulfoxide (DMSO) with polyvinyl alcohol (PVA) was applied. Nanocrystalline diamond (NCD) films were deposited on the fibres using the microwave plasma assisted chemical vapour deposition...
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Quenching effects in organic electroluminescence
PublicationWe examine various electronic processes that underlie the quenching of the emission from highly efficient phosphorescent and electrophosphorescent organic solid-state molecular systems. As an example, we study the luminescent efficiencies from the phosphorescent iridium (III) complex, fac tris (2-phenylpyridine) iridium [(Ir (ppy)3] doped into a diamine derivative doped polycarbonate hole-transporting matrix and in the form...
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Cavitation-based technologies for pretreatment and processing of food wastes: Major applications and mechanisms – A review
PublicationConversion of food wastes to valuable products is an important topic for sustainable development. Feedstock hydrolysis is a stage strongly affecting the anaerobic digestion process, and resistance of food waste towards hydrolysis causes a decrease in product yield. Such as biomethane, biohydrogen, biohythane, VFAs, and lactic acids. Moreover, mass transfer is a serious limitation of transesterification for the production of biodiesel....
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Expedited Yield Optimization of Narrow- and Multi-Band Antennas Using Performance-Driven Surrogates
PublicationUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of antenna systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the antenna characteristics. In the case of narrow- or multi-band antennas, this usually leads to...