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Wyniki wyszukiwania dla: Stability of borophene dispersion
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Buckling analyses of metal cylindrical silos containing bulk solids during filling
PublikacjaThe paper presents 3D results on stability of thin-walled cylindrical metal silos made of isotropic rolled and corrugated plates containing bulk solids. The behavior of bulk solids was described using a hypoplastic constitutive model. Nonlinear finite element (FE) analyses with both geometric and material nonlinearity were performed with a perfect and an imperfect silo shell wherein initial geometric imperfections were taken into...
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Proaktywne podejście geotechniczne do zachowania dziedzictwa kulturowego i naturalnego: przypadek San Leo we Włoszech Proactive Geotechnical Approach to Preserve Cultural and Natural Heritage: The Case of the Town of San Leo in Italy
PublikacjaArtykuł dotyczy miasta San Leo, znanego z atrakcyjnych zabytków historycznych, zwłaszcza twierdzy Rocca Fortezza stanowiącej architektoniczne arcydzieło. Jest ona położona na wysokiej skale, której zbocza od setek lat ulegały procesom osuwiskowym. Najpoważniejsze osuwisko miało miejsce w 2014. Aby uniknąć potencjalnej katastrofy i zapewnić bezpieczeństwo miastu, w pracy przeprowadzono analizę proaktywną, polegającą na przewidywaniu...
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Tworzenie miejskości po 1990r., Geneza niemieckiej urbanistyki współczesnych założeń mieszkaniowych
PublikacjaArtykuł jest przyczyną do przypomnienia genezy współczesnej formy niemieckich miejskich struktur mieszkaniowych w kontekście zmian rozumienia ich wymiaru miejskości. Niemiecka myśl urbanistyczna łączy w sobie dwie wyraziste tradycje dwudziestego wieku - Gründerzeit i KlassischeModerne. Pozostaje jednak silnie otwarta na innowację generowaną nie tylko dzięki postępowi technicznemu, ale przede wszystkim poprzez planowanie interdyscyplinarne...
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Isothermal Vulcanization and Non-Isothermal Degradation Kinetics of XNBR/Epoxy/XNBR-g-Halloysite Nanotubes (HNT) Nanocomposites
PublikacjaThe effect of several concentrations of carboxylated nitrile butadiene rubber (XNBR) functionalized halloysite nanotubes (XHNTs) on the vulcanization and degradation kinetics of XNBR/epoxy compounds were evaluated using experimental and theoretical methods. The isothermal vulcanization kinetics were studied at various temperatures by rheometry and differential scanning calorimetry (DSC). The results obtained indicated that the...
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On Wrinkling in Sandwich Panels with an Orthotropic Core
PublikacjaThis paper deals with the local loss of stability (wrinkling) problem of a thin facing of a sandwich panel. Classical solutions to the problem of facing instability resting on a homogeneous and isotropic substructure (a core) are compared. The relations between strain energy components associated with different forms of core deformations are discussed. Next, a new solution for the orthotropic core is presented in detail, which...
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VIBRATION SURVEILLANCE DURING MILLING OF FLEXIBLE DETAILS WITH A USE OF THE ACTIVE OPTIMAL CONTROL
PublikacjaThe main goal of modern machining operations is to achieve increasingly better performance. High Speed Machining and/or High Performance Cutting, despite a lot of advantages, have also some drawbacks, for example, a possibility of losing stability and development of self-excited chatter vibration. This paper presents an approach of vibration surveillance during high speed milling with a use of active optimal control. Non-stationary...
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Fungal L-Methionine Biosynthesis Pathway Enzymes and Their Applications in Various Scientific and Commercial Fields
PublikacjaL-methionine (L-Met) is one of the nine proteinogenic amino acids essential for humans since, in human cells, there are no complete pathways for its biosynthesis from simple precursors. L-Met plays a crucial role in cellular function as it is required for proper protein synthesis, acting as an initiator. Additionally, this amino acid participates in various metabolic processes and serves as a precursor for the synthesis of S-adenosylmethionine...
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Nanocrystalline cathode functional layer for SOFC
PublikacjaRecently, it was shown that thin functional layers introduced between an electrolyte and cathode might improve cathode performance. However, the mechanism of this improvement still needs analysis. In this paper, a thin (∼140 nm), spin-coated perovskite layer (La0.6Sr0.4Co0.2Fe0.8O3-δ) was placed between a cathode (La0.6Sr0.4Co0.2Fe0.8O3-δ) and an electrolyte (Ce0.8Gd0.2O2-δ) and the effects of this investigated. The microstructure...
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Dynamic Electrochemical Impedance Spectroscopy (DEIS) as a Tool for Analyzing Surface Oxidation Processes on Boron-Doped Diamond Electrodes
PublikacjaSurface oxidation processes play a key role in understanding electrochemical properties of boron-doped diamond (BDD) electrodes. The type of surface termination groups, which create the potential window of electrolytic water stability or hydrophobicity, influences such properties. In this study the kinetics of oxidation process under anodic polarization were studied in situ by means of Dynamic Electrochemical Impedance Spectroscopy...
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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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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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A new approach of coastal cliff monitoring using Mobile Laser Scanning
PublikacjaThe article proposes a new approach of coastal cliff monitoring which bases on a new comprehensive monitoring system, being a combination of mobile scanning from the sea with the geotechnical stability analysis. Mobile laser scanning is an innovative solution for 3D data collection which allows the monitored object geometry to be precisely measured, thus providing opportunities for series of analyses contributing to the development...
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Buckling of thin-walled columns accounting for initial geometrical imperfections
PublikacjaThe paper is devoted to the effect of some geometrical imperfections on the critical buckling load of axially compressed thin-walled I-columns. The analytical formulas for the critical torsional and flexural buckling loads accounting for the initial curvature of the column axis or the twist angle respectively are derived. The classical assumptions of theory of thin-walled beams with non-deformable cross-sections are adopted. The...
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An interval estimator for chlorine monitoring in drinking water distribution systems under uncertain system dynamics, inputs and chlorine concentration measurement errors
PublikacjaThe design of an interval observer for estimation of unmeasured state variables with application to drinking water distribution systems is described. In particular, the design process of such an observer is considered for estimation of the water quality described by the concentration of free chlorine. The interval observer is derived to produce the robust interval bounds on the estimated water quality state variables. The stability...
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Amyloid fibril formation in the presence of water structure-affecting solutes
PublikacjaThe impact of the differently hydrated non-electrolytes (protein structure destabilizers) on the fibrillation of hen egg white lysozyme (HEWL) was investigated. Two isomeric urea derivatives i.e. butylurea (BU) and N,N,N′,N′-tetramethylurea (TMU) were chosen as a tested compounds. The obtained results show that butylurea exerts greater impact on HEWL and its fibrillation than tetramethylurea. Both substances decrease the time of...
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Electrophoretic deposition and characterization of composite chitosan/Eudragit E 100 or poly(4-vinylpyridine)/mesoporous bioactive glass nanoparticles coatings on pre-treated titanium for implant applications
PublikacjaTitanium implants are surface-modified to achieve bioactivity and often antibacterial properties. Such surface coatings may increase corrosion degradation and be weakly attached to the substrate. In the present research, biodegradable composite coatings, investigated so far as smart environment-sensitive, slowly releasing silver to the implant neighborhood, were produced as a combination of chitosan (CS) with Eudragit E 100 (EE100)...
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Experiments on compression ignition engine powered by nano-fuels
PublikacjaThe use of nanoparticles in fuels provides new opportunities for modification of fuel properties, which may affect the operational parameters of engines, in particular the efficiency and fuel consumption. The paper presents comparison of compression ignition engine performance fuelled with neat diesel and nano-diesel. Alumina (Al2O3) was used as nanoparticles. Surface-active substances, including Span 80 surfactant, as well as...
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Pervaporation Zeolite-Based Composite Membranes for Solvent Separations
PublikacjaThanks to their well-defined molecular sieving and stability, zeolites have been proposed in selective membrane separations, such as gas separation and pervaporation. For instance, the incorporation of zeolites into polymer phases to generate composite (or mixed matrix) membranes revealed important advances in pervaporation. Therefore, the goal of this review is to compile and elucidate the latest advances (over the last 2-3 years)...
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Flexomagnetic response of buckled piezomagnetic composite nanoplates
PublikacjaIn this paper, the equation governing the buckling of a magnetic composite plate under the influence of an in-plane one-dimensional magnetic field, assuming the concept of flexomagnetic and considering the resulting flexural force and moment, is investigated for the first time by different analytical boundary conditions. To determine the equation governing the stability of the plate, the nonlocal strain gradient theory has been...
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MEMORY EFFECT ANALYSIS USING PIECEWISE CUBIC B-SPLINE OF TIME FRACTIONAL DIFFUSION EQUATION
PublikacjaThe purpose of this work is to study the memory effect analysis of Caputo–Fabrizio time fractional diffusion equation by means of cubic B-spline functions. The Caputo–Fabrizio interpretation of fractional derivative involves a non-singular kernel that permits to describe some class of material heterogeneities and the effect of memory more effectively. The proposed numerical technique relies on finite difference approach and cubic...
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Lower Rim Substituted p-tert-Butyl-Calix[4]arene. Part 16. Synthesis of 25, 26, 27, 28-tetrakis(piperidinethiocarbonylmethylene)-p-tert-butylcalix[4]arene and its interaction with metal ions
PublikacjaThe synthesis, characterisation and X-ray crystal structures of p-tert-butyl-calix[4]arenethioamide L and its complex with lead L-Pb2+ is reported. The cation-binding properties in solution have been assessed by liquid-liquid extraction of the metal picrates from water into dichloromethane and by stability constants determination in acetonitrile using UV-absorption spectrophotometry or potentiometry. The compound was used as active...
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Monitoring Parkinson's disease patients employing biometric sensors and rule-based data processing
PublikacjaArtykuł prezentuje automatyczny system wykrywania pogorszenia zdrowia pacjentów z chorobą Parkinsona opracowany w ramach projektu PERFORM.The paper presents how rule-based processing can be applied to automatically evaluate the motor state of Parkinson's Disease patients. Automatic monitoring of patients by using biometric sensors can provide assessment of the Parkinson's Disease symptoms. All data on PD patients' state are compared...
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Effects of the polyhistidine tag on kinetics and other properties of trehalose synthase from Deionococcus geothermalis
PublikacjaTwo recombinant trehalose synthases from Deinococcus geothermalis (DSMZ 11300) were compared. A significant influence of the artificial polyhistidine tag was observed in protein constitution. The recombinant trehalose synthase from D. geothermalis with His6 -tag has a higher K m value of 254 mM, in comparison with the wild-type trehalose synthase (K m 170 mM), and displayed a lower activity of maltose conversion when compared...
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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Throughput-Coverage Characteristics for Soft and Partial Frequency Reuse in the LTE Downlink
PublikacjaThe paper presents results of simulation and evaluation of throughput-coverage characteristics for the OFDMA-based LTE network with Soft Frequency Reuse or Partial Frequency Reuse. Firstly, simulation results of throughput characteristics for a single user connection are presented, which allow the evaluation of the stability and availability of bit rate achieved in different areas of a cell. Secondly, the capacity characteristics...
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Wpływ smarowności na działania układu tribologicznego (impact of lubricity on the tribological system action)
Publikacjathe paper presents analysis and evaluation, based on tests results, of the impact of lubricity of the used lubricating oils (shell argina t 40) on the action of boundary layer of sulzer 6zl40/48 engines aboard the ''włocławek'' sea-going ship. for comparison purposes, the same oils were tested with the ceramizer four-stroke engine (all types of the vidar four-stroke engines) regeneration agent added. so understood boundary layer...
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Recent Advances in Graphene Oxide-Based Membranes for Heavy Metal Ions Separation
PublikacjaGraphene oxide (GO)-based membranes have been widely investigated for separation of dyes, salt ions, heavy metal ions, and biomolecules due to their high mechanical strength, single-layered structure, large surface area, and high affinity. However, due to irregular pore structure, nanochannels, interlayer distance, easy functionalization, swelling effect, and chemical stability under aqueous environment limited their separation...
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Non-Adaptive Speed and Position Estimation of Doubly-Fed Induction Generator in Grid-Connected Operations
PublikacjaThe nonadaptive speed and position estimation scheme for a doubly-fed induction generator (DFIG) is presented in this article. The observer structure is based on the extension of the mathematical model of DFIG to the introduced H vector. Based on the defined H vector, the nonadaptive position and speed estimation is proposed. The Lyapunov method is extended to the practical stability theorem to stabilize the structure. The classic...
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BIOMATERIALS AND IMPLANTS IN CARDIAC AND VASCULAR SURGERY - REVIEW
PublikacjaCurrently, on prosthesis in cardiac blood vessels and heart valves are used materials of animal or synthetic origin. For animal materials include, among others pericardial sac in which is the heart. Materials such as this (natural) are characterized by a remarkable biocompatibility within the human body, but their main disadvantage is the relatively low durability. In turn, synthetic materials, which include the austenitic chromium-nickel-molybdenum...
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Thermal and Mechanical Properties of Microporous Polyurethanes Modified with Reduced Graphene Oxide
PublikacjaMicroporous polyurethanes (MPU) were modified by adding 0.25%–1.25 wt% of reduced graphene oxide (RGO). The materials were prepared without solvent via in situ polymerization. From a technological point of view, it is very important to obtain functional materials by using reacting compounds only. The thermal characteristics of obtained MPU were investigated using TGA, DSC, and DMA techniques. In comparison to nonmodified microporous...
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Green aspects of techniques for the determination of pesticides in fruits and vegetables
PublikacjaApplied all over the world, pesticides are some of the most dangerous pollutants of the environment because of their stability, mobility, their ability to accumulate in the environment and their consequent long-term adverse effects on living organisms in general and human health in particular. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical...
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Hydrogen effects in duplex stainless steel welded joints - electrochemical studies
PublikacjaIn this work results on the influence of hydrogen on passivity and corrosion resistance of 2205 duplex stainless steel (DSS) welded joints are described. The results were discussed by taking into account three different areas on the welded joint: weld metal (WM), heat-affected zone (HAZ) and parent metal. The corrosion resistance was qualified with the polarization curves registered in a synthetic sea water. The conclusion is that,...
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Sparse autoregressive modeling
PublikacjaIn the paper the comparison of the popular pitch determination (PD) algorithms for thepurpose of elimination of clicks from archive audio signals using sparse autoregressive (SAR)modeling is presented. The SAR signal representation has been widely used in code-excitedlinear prediction (CELP) systems. The appropriate construction of the SAR model is requiredto guarantee model stability. For this reason the signal representation...
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RuAl6—An Endohedral Aluminide Superconductor
PublikacjaSuperconductivity is reported in an endohedral aluminide compound, RuAl6, with Tc = 1.21 K. The normalized heat capacity jump at Tc, ΔC/γTc = 1.58, confirms bulk superconductivity. The Ginzburg–Landau parameter of κ = 9.5 shows that RuAl6 is a type-II superconductor. Electronic structure calculations for RuAl6 are explored in comparison to its structural analogue ReAl6 (Tc = 0.74 K). The stability of the phases is discussed in...
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Examining Quality of Hand Segmentation Based on Gaussian Mixture Models
PublikacjaResults of examination of various implementations of Gaussian mix-ture models are presented in the paper. Two of the implementations belonged to the Intel’s OpenCV 2.4.3 library and utilized Background Subtractor MOG and Background Subtractor MOG2 classes. The third implementation presented in the paper was created by the authors and extended Background Subtractor MOG2 with the possibility of operating on the scaled version of...
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Physical and Thermophysical Properties of 1-Hexyl-1,4-diaza[2.2.2]bicyclooctanium Bis(trifluoromethylsulfonyl)imide Ionic Liquid
PublikacjaOwing to their unique properties, ionic liquids (ILs) have become a real alternative to organic compounds. Nowadays, ILs are commonly used in a number of areas such as chemical synthesis and separation techniques. However, ionic liquids continue to have a limited applicability in industry because the information on their physical and chemical properties is not readily available. This paper presents, for the first time, the results...
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Formation enthalpies of LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) interlanthanide perovskites
PublikacjaHigh-temperature oxide melt solution calorimetry using 3Na2O·MoO3 at 802 °C was performed for interlanthanide perovskites LaLn׳O3 (Ln׳=Ho, Er, Tm and Yb) and lanthanide oxides (La2O3, Ho2O3, Er2O3, Tm2O3 and Yb2O3). The enthalpies of formation of these interlanthanide perovskites from binary lanthanide oxides at room temperature (25 °C) were determined to be −8.3±3.4 kJ/mol for LaHoO3, −9.9±3.0 kJ/mol for LaErO3, −10.8±2.7 kJ/mol...
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Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible Light
PublikacjaTo develop highly efficient molecular photocatalysts for visible light-driven hydrogen production, a thorough understanding of the photophysical and chemical processes in the photocatalyst is of vital importance. In this context, in situ X-ray absorption spectroscopic (XAS) investigations show that the nature of the catalytically active metal center in a (N^N)MCl2 (M=Pd or Pt) coordination sphere has a significant impact on the...
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MXene-based materials for removal of antibiotics and heavy metals from wastewater– a review
PublikacjaAs a novel family of 2D materials, MXenes provide an extensive variety of applications in water and effluent treatment due to their distinctive properties and attractive applicability, including superior electrical conductivity, higher thermal stability, hydrophilicity, and high sorption-reduction capacity. Their excellent sorption selectivity makes them perfect for removing hazardous contaminants. Currently, MXene-based materials...
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Exfoliated graphite with spinel oxide as an effective hybrid electrocatalyst for water splitting
PublikacjaThe aim of the conducted research was to develop hybrid nanostructures formed from MnCo2O4 and exfoliated graphite. Carbon added during the synthesis allowed for obtaining a well-distributed MnCo2O4 particle size with exposed active sites contributing to the increased electric conductivity. The influence of the weight ratios of carbon to a catalyst for hydrogen and oxygen evolution reactions was investigated. The new bifunctional...
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Chromogenic azomacrocycles with imidazole residue: Structure vs. properties
PublikacjaNew diazo macrocycles linked by hydrocarbon chain bearing imidazole or 4-methylimidazole residue have been synthetized with satisfactory yield (24–55%). The structure of macrocycles was confirmed by X-ray analysis and spectroscopic methods (1H NMR, MS, FTIR). Metal cation complexation studies were carried out in acetonitrile and acetonitrile-water system. It was found that azomacrocyles form triple-decker complexes with lead(II)....
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Performance Evaluation of Asphalt Binder Modified with Shear Thickening Fluid
PublikacjaThis paper aims at using a dilatant or shear thickening fluid (STF) [a non-Newtonian fluid consisting of particles of nano-silica suspended in a liquid medium, i.e., ethylene glycol (EG), which acts as a carrier fluid; proportion 40:60] as additive or modifier of bitumen in order to enhance its viscoelastic properties. A commonly-used performance grading (PG) system, storage stability test, and different conventional and rheological...
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Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublikacjaThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
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The effect of Sr and Mg substitutions on structure, mechanical properties and solubility of fluorapatite ceramics for biomedical applications
PublikacjaIonic substitutions play important role in the modifications of biological apatites. Recently, attention has been focused on the co-doping effects on the functional properties of apatite-based biomaterials. In this research work, the dense samples of fluorapatites, Ca10(PO4)6F2 and Ca8MgSr(PO4)6F2, were produced after sintering at 1250 °C for 6 h in air. Structural characterization carried out with XRD, IR, Raman and SEM, confirmed...
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Determination of the minimal critical rotational speeds of the circular saw blades with the quasi-twin resonant frequencies
PublikacjaTo determine the minimal critical rotational speeds of the circular saw blades is the fundamental aspect of obtaining the range of the rotational operating speeds, by which the circular saw blade can work with required stability. While for the circular saw blades with full-homogeneous bodies the determination of such rotational speeds is the relatively low level of difficulty function, whereas for circular saw blades with more...
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Hydrographic Multisensory Unmanned Watercraft
PublikacjaThis article describes the design of the unmanned surface vessel (USV) and the algorithms for planning the trajectories to be followed on measurement missions. The algorithms take account of the dynamically varying impacts of external forces (wind and surface current) on the vessel's motion. Feedback loops enable the counteraction of external factors that cause disturbance to the desired trajectory. The sensors installed on the...
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Asynchronous WAM with Irregular Pulse Repetition
PublikacjaRadiolocation systems for aviation based on Multi-Lateration (MLAT) typically use a set of synchronised ground sensors to receive radio signals broadcast by onboard transmitters. In most cases, the sensor synchronisation in Wide Area Multi-Lateration Systems (WAM) is provided by Global Navigation Satellite System (GNSS) receivers. However, in the case of synchronisation failure, there is still a possibility to estimate the coordinates...
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Local buckling of thin-walled channel member flange made of aluminum alloy
PublikacjaThe paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential...
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Copper and cobalt co-doped ceria as an anode catalyst for DIR-SOFCs fueled by biogas
PublikacjaThe nanocrystalline compounds of Co and Cu co-doped ceria (with up to 20 mol.% of dopants) were fabricated by the reverse microemulsion synthesis method. They were deposited in a form of layers on the surface of SOFC anode in an aim to act as electrochemically active materials for biogas reforming process. Fourier Transformed Infrared Spectroscopy was used to analyze a composition of outlet gases simultaneously with the tests of...
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Antimicrobial Activity of Chimera Peptides Composed of Human Neutrophil Peptide 1 (HNP-1) Truncated Analogues and Bovine Lactoferrampin
PublikacjaThree chimera peptides composed of bovine lactoferrampin and the analogue of truncated human neutrophil peptide 1 were synthesized by the solid-phase method. In two compounds peptide chains were connected via isopeptide bond, whereas in the third one disulfide bridge served as a linker. All three chimeras displayed significantly higher antimicrobial activity than the constituent peptides as well as their equimolar mixtures. The...