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Wyniki wyszukiwania dla: effective elastic constants
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Impact of Tensile and Compressive Stress on Classical and Acoustic Barkhausen Effects in Grain-Oriented Electrical Steel
PublikacjaIn this paper, we present the results of the investigation of impact of tensile and compressive stress on the classical Barkhausen effect, magnetoacoustic emission (MAE) signal properties, and B(H) hysteresis loops for grain-oriented (GO) electrical steel. Samples have been glued to a nonmagnetic steel bar and stressed within elastic range (±800 μdef) by means of four-point bending method. The samples were cut out in two directions...
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TIME-AND-SPACE STRUCTURE OF FORCE-DRIVEN RIGID SPHEREWAVEFIELD
PublikacjaThis paper introduces a time-domain, causality-inspired description of a vector-source acoustic wavefield of arbitrary time evolution, where a sphere is a practical realisation of quasi-point contact surface without which a point force would not be able to exert an impact onto non-viscous fluid. At every space location, the resulting acoustic field is described by a pair of physical variables characterising the time evolution of...
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Electron collisions with cyanoacetylene HC3N : Vibrational excitation and dissociative electron attachment
PublikacjaWe experimentally probe electron collisions with HC3N in the energy range from 0 to 10 eV with the focus on vibrational excitation and dissociative electron attachment. The vibrational excitation cross sections show a number of resonances which are mode specific: the two dominant π∗ resonances are visible in the excitation of all the vibrational modes; however, broad σ ∗ resonances are visible only in certain bond-stretching vibrational...
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Seismic pounding behavior of multi-story buildings in series considering the effect of infill panels
PublikacjaThe aim of the present paper is to study the influence of the infill panels on the seismic pounding response of adjacent structures in series. The contribution of the masonry infill has been simulated using equivalent diagonal compression struts. Steel frames have been assumed to have elastic-plastic behavior with 1% linear strain hardening. The dynamic contact analysis has been utilized where contact surface model (target and...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublikacjaThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublikacjaThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...
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Electron scattering from tin tetrachloride (SnCl4) molecules
PublikacjaAbsolute grand-total cross section (TCS) for electron scattering from a tin tetrachloride, SnCl4, molecule was measured at electron-impact energies ranging from 0.6 to 300 eV, in the linear electron-transmission experiment. The measured TCS energy dependence shows two very pronounced enhancements peaking near 1.2 eV and around 9.5 eV, separated with a deep minimum centered close to 3 eV. The low energy structure is attributed to...
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The Selection of Anchoring System for Floating Houses by Means of AHP Method
PublikacjaThis paper indicates and analyses the use of anchoring systems, such as mooring piles, booms, mooring cables, and deadweight anchors with additional elastic connectors, which are the most frequently applied by the producers of floating houses. The selection of the most advantageous anchoring system is complicated and requires the application of quantitative and qualitative data and methods. This publication presents the results...
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Effects of Surface Energy and Surface Residual Stresses on Vibro-Thermal Analysis of Chiral, Zigzag, and Armchair Types of SWCNTs Using Refined Beam Theory
PublikacjaIn this article, vibration characteristics of three different types of Single-Walled Carbon Nanotubes (SWCNTs) such as armchair, chiral, and zigzag carbon nanotubes have been investigated considering the effects of surface energy and surface residual stresses. The nanotubes are embedded in the elastic substrate of the Winkler type and are also exposed to low and high-temperature environments. A new refined beam theory namely, one-variable...
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Field tests on hydrodynamic and hybrid operation of a bi-directional thrust bearing of a pump-turbine
PublikacjaIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Because of bi-directional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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Field Tests on Hydrodynamic and Hybrid Operation of a Bidirectional Thrust Bearing of a Pump-Turbine
PublikacjaIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Due to the bidirectional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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On dynamic modeling of piezomagnetic/flexomagnetic microstructures based on Lord–Shulman thermoelastic model
PublikacjaWe study a time-dependent thermoelastic coupling within free vibrations of piezomagnetic (PM) microbeams considering the flexomagnetic (FM) phenomenon. The flexomagneticity relates to a magnetic field with a gradient of strains. Here, we use the generalized thermoelasticity theory of Lord–Shulman to analyze the interaction between elastic deformation and thermal conductivity. The uniform magnetic field is permeated in line with...
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Modeling of Electrodynamic Phenomena in an Ultra-Rapid Inductive–Dynamic Actuator as Applied to Hybrid Short-Circuit Breakers - A Review Study
PublikacjaThis article is a study of the research development of electrodynamic phenomena occurring in ultra-fast electrodynamic drives. These types of linear drives are among the fastest, not only because of the huge accelerations achieved, but, above all, because of the extremely short reaction time. For this reason, electrodynamic drives are used in hybrid short-circuit breakers. The phenomena occurring in this type of drive are actually...
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Local material symmetry group for first- and second-order strain gradient fluids
PublikacjaUsing an unified approach based on the local material symmetry group introduced for general first- and second-order strain gradient elastic media, we analyze the constitutive equations of strain gradient fluids. For the strain gradient medium there exists a strain energy density dependent on first- and higher-order gradients of placement vector, whereas for fluids a strain energy depends on a current mass density and its gradients....
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Mechanical Behavior of Bi-Layer and Dispersion Coatings Composed of Several Nanostructures on Ti Substrate
PublikacjaThree coatings suitable for biomedical applications, including the dispersion coating composed of multi-wall carbon nanotubes (MWCNTs), MWCNTs/TiO2 bi-layer coating, and MWCNTs-Cu dispersion coating, were fabricated by electrophoretic deposition (EPD) on Ti Grade II substrate. Optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and nanoindentation were applied to study topography, chemical, and...
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Computational fluid dynamics - lustres and shadows.
PublikacjaThe paper is devoted to the different aspects of CFD. The advantages of this concept are evident and obvious; powerfuk and effective tools bring this technology closer to the quantifiable world. However, certain weaknesses in this structure are apparent. Sometimes, a simplistic tendency towards simplifications and facilitations may degenerate and lead to negative behaviours and signs. These have not been serious up to date, but...
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Nodal cooperation equilibrium analysis in multi-hop wireless ad hoc networks with a reputation system
PublikacjaMotivated by the concerns of cooperation security, this work examines selected principles of state-of-the-art reputation systems for multi-hop ad hoc networks and their impact upon optimal strategies for rational nodes. An analytic framework is proposed and used for identification of effective cooperation-enforcement schemes. It is pointed out that optimum rather than high reputation can be expected to be sought by rational nodes.
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Geokompozyty drenażowe w odwodnieniach drogowych i kolejowych
PublikacjaZagadnienie zagospodarowania wód opadowych i gruntowych w rejonie konstrukcji drogowych i kolejowych stanowi istotny element bezpiecznej i efektywnej eksploatacji tych obiektów. Odpowiednie wykorzystanie geokompozytów drenażowych zapewnia bezproblemową pracę konstrukcji oraz właściwą ochronę przed uszkodzeniami wynikającymi z niekontrolowanego oddziaływania wody.
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Asynchronous Charge Carrier Injection in Perovskite Light-Emitting Transistors
PublikacjaUnbalanced mobility and injection of charge carriers in metal-halide perovskite light-emitting devices pose severe limitations to the efficiency and response time of the electroluminescence. Modulation of gate bias in methylammonium lead iodide light-emitting transistors has proven effective in increasing the brightness of light emission up to MHz frequencies. In this work, a new approach is developed to improve charge carrier...
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Chitosan-based electrospun nanofibers for encapsulating food bioactive ingredients: A review
PublikacjaToday, society has been more aware of healthy food products and related items containing bioactive compounds, which potentially contribute to human health. Unfortunately, the long-term stability and bioactivity of biologically active compounds against environmental factors compromise their target and effective action. In this way, lab-designed vehicles, such as nanoparticles and nanofibers, provide enough properties for their preservation...
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BACTERIAL INACTIVATION VIA LASER-DRIVEN GOLD NANOPARTICLE HEATING: SIMULATION AND ANALYSIS
PublikacjaThis study utilizes CFD technique to simulate the inactivation of E. coli bacteria within a microfluidic chamber, employing gold nanoparticles irradiated by a laser beam. Employing a single-phase model, the presence of bacteria is considered by treating thermal properties in the governing equations as effective, combining those of water and bacteria using established correlations from scientific literature. The conversion of light...
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Badania eksperymentalne strefy przypodporowej żelbetowych belek częściowo sprężonych
PublikacjaThis project refers to the study the shear zone, under full and partial prestressing in comparison to beams with passive reinforcement.For comparison, variable parameters have been determined:- a/d (from 1,5 to 3,5) - it's shear span to effective depth of the beam . Assuming constant geometrical quantities, "a" is variable.- 26 beams had no vertical shear reinforcement, and the other 26 had closed stirrups.- prestressing intensity...
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Shaking table experimental study on the effectiveness of polymer bearings for seismic isolation of structures
PublikacjaSeismic isolation has been recognised to be a very effective way of protecting structures from damage during earthquakes. It allows us to extend the natural period of the structure and therefore avoid resonance with the ground motion. Moreover, by increasing damping in the isolation devices, more energy can be dissipated and thus the structural response can be further reduced. The aim of this paper is to show the results of the...
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Numerical evaluation of dynamic response of an experimentally tested base-isolated and fixed-base steel structure model
PublikacjaSeismic isolation is recognized as one of the most popular and effective methods of protecting structures during earthquake. The present paper is focused on the comparison be-tween the dynamic responses of buildings with fixed and isolated bases exposed to seismic exci-tations. The aim of the study is to investigate the effectiveness of a simplified base isolation numerical modelling technique using the linear springs. One-storey...
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A New Method of the Load Compensation Use During Creation of Post Blackout Start-up Path in Power System
PublikacjaIn the paper a new method of effective use of load compensation during creation of post blackout start-up path is proposed. Theoretical assumptions and simulation results of an investigation are presented. An experiment performed in the Polish Power System is also described. This experiment proved that the method proposed by the authors is advisable. The method may be utilized by power system operators for power system restoration...
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Doskonalenie procesu zarządzania zespołem w oparciu o zróżnicowanie typów MBTI
PublikacjaArtykuł dotyczy możliwości praktycznego wykorzystania koncepcji MBTI w procesie zarządzania zespołami. Zaprezentowano wyniki badań przeprowadzonych na osobach aktywnych zawodowo, które wzięły udział w analizie typów MBTI. Główna rekomendacja wynikająca z przeprowadzonych analiz dotyczy wykorzystania koncepcji MBTI do efektywnego zarządzania psychologicznym zróżnicowaniem zespołu.
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Highly efficient maximum power point tracking control technique for PV system under dynamic operating conditions
PublikacjaThe application of small-scale electrical systems is widespread and the integration of Maximum Power Point Tracking (MPPT) control for Photovoltaic systems with battery applications further enhances the techno-economic feasibility of renewable systems. For this purpose, a novel MPPT control system using Dynamic Group based cooperation optimization (DGBCO) algorithm is utilized for PV systems. The population in the DGBCO is divided...
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Role of the disulfide bond in stabilizing and folding of the fimbrial protein DraE from uropathogenic Escherichia coli
PublikacjaDr fimbriae are homopolymeric adhesive organelles of uropathogenic Escherichia coli composed of DraE subunits, responsible for the attachment to host cells. These structures are characterized by enormously high stability resulting from the structural properties of an Ig-like fold of DraE. One feature of DraE and other fimbrial subunits that makes them peculiar among Ig-like domain-containing proteins is a conserved disulfide bond...
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Static magnetic multipole susceptibilities of the relativistic hydrogenlike atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublikacjaWe study far- and near-field magnetic and electric multipole moments induced in the ground state of the Dirac one-electron atom placed in a weak 2L-pole magnetostatic field. The analysis is carried out within the framework of the first-order Rayleigh-Schrödinger perturbation theory, with the use of the Sturmian expansion of the generalized Dirac-Coulomb Green function [Szmytkowski, J. Phys. B 30, 825 (1997);J. Phys. B 30, 2747(E)...
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Sugar matters: sugar moieties as reactivity-tuning factors in quercetin O-glycosides
PublikacjaQuercetin, one of the most abundant flavonoids in plant-based foods, commonly occurs in nature in various glycosylated forms. There is still a less explored aspect regarding the cause of its glycosides diversity, depending on the sugars moiety attached. This work focuses on four widespread quercetin glycosides—hyperoside, isoquercitrin, quercitrin and rutin—by testing property-tuning capacity of different sugar moieties and thus...
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First deep eutectic solvent-based (DES) stationary phase for gas chromatography and future perspectives for DES application in separation techniques
PublikacjaThe paper presents the first application of deep eutectic solvents (DES) as stationary phases for gas chromatography. DES obtained by mixing tetrabutylammonium chloride (TBAC) as a hydrogen bond acceptor (HBA) with heptadecanoic acid being a hydrogen bond donor (HBD) in a mole ratio of HBA:HBD equal to 1:2 was characterized by its ability to separate volatile organic compounds (VOCs). The Rohrschneider – McReynolds constants determined...
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Synthesis, Chemical Characterization and Multiscale Biological Evaluation of a dimericcRGD Peptide for Targeted Imaging of αVβ3 Integrin Activity
PublikacjaCyclic peptides containing the Arg-Gly-Asp (RGD) sequence have been shown to specifically bind the angiogenesis biomarker α V β3 integrin. We report the synthesis, chemical characterization, and biological evaluation of two novel dimeric cyclic RGD-based molecular probes for the targeted imaging of α V β3 activity (a radiolabeled version, 64Cu-NOTA-PEG4-cRGD2, for PET imaging, and a fluorescent version, FITC-PEG4-cRGD2, for in...
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Phototransformation of three selected pharmaceuticals, naproxen, 17α-Ethinylestradiol and tetracycline in water: Identification of photoproducts and transformation pathways
PublikacjaTransformation products (TPs) may be formed during various processes, however, it was proved that one of the main mechanisms responsible for degradation of pharmaceuticals in natural waters is photolysis. Three compounds were selected, tetracycline (TC), 17-α-ethinylestradiol (EE2) and naproxen (NAP), for degradation experiments which were performed using a xenon lamp emitting light with a spectrum closely approximating that of...
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Estimation of the uncertainty of the AC/AC transducer output voltage
PublikacjaThe paper presents a methodology for estimating uncertainty of voltage transducers processing function, on the example of CYVS411D07 voltage transducers. The analysis was conducted using the method based on the GUM Guide propagation of uncertainty law and the determination of the coverage factor based on the effective number of degrees of freedom (t-Student distribution). The paper also presents example evaluation results of measured...
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TOXIC GASES IDENTIFICATION USING SINGLE ELECTROCATALYTIC SENSOR RESPONSES AND ARTIFICIAL NEURAL NETWORK
PublikacjaThe need for precise detection of toxic gases drives development of new gas sensors structures and methods of processing the output signals from the sensors. In literature, artificial neural networks are considered as one of the most effective tool for the analysis of gas sensors or sensors arrays responses. In this paper a method of toxic gas components identification using a electrocatalytic gas sensor as a detector and an artificial...
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Application of quartz crystal microbalance and dynamic impedance spectroscopy to the study of copper corrosion inhibitors
PublikacjaThe study investigates the application of Dynamic Electrochemical Impedance Spectroscopy (DEIS) and Electrochemical Quartz Crystal Microbalance (EQCM) techniques to examine the corrosion inhibition of copper by Benzotriazole and Sodium Folate in a 0.1 M NaCl solution. DEIS, an advanced version of Electrochemical Impedance Spectroscopy (EIS), allows for real-time monitoring of non-stationary electrochemical systems,...
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Analytical Steady-State Model of the Pipeline Flow Process
PublikacjaThe paper addresses the issue of modeling the flow process in transmission pipelines. A base model used for numerical simulation is introduced. Under certain assumptions concerning steady state analysis, the differential equations describing the process are solved analytically for two cases: zero and nonzero inclination angle α. These equations describe a constant flow rate and a corresponding distribution of the pressure along...
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Organizational IT Competency, Knowledge Workers and Knowledge Sharing
PublikacjaIT competency plays a vital role in knowledge management processes. Information technology affects an organization’s ability to store and recall knowledge that has been made explicit through codification, including different forms such as written documents, reports, presentations, patents, formulas, etc. This study aims to measure the influence of a company’s IT competency dimensions such as IT-knowledge,...
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Project-Based Learning as a Method for Interdisciplinary Adaptation to Climate Change—Reda Valley Case Study
PublikacjaThe challenges of the global labour market require university authorities to extend traditional forms of education into more innovative and effective solutions. Project-based learning (PjBL) is one of highly effective methods for acquiring knowledge and teaching “soft” skills to future employees. This article describes an experimental use of PjBL at a university with a long history of teaching based on traditional methods—the Gdansk...
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In Vitro Biological Characterization of Silver-Doped Anodic Oxide Coating on Titanium
PublikacjaDespite the high biocompatibility and clinical effectiveness of Ti-based implants, surface functionalization (with complex osteointegrative/antibacterial strategies) is still required. To enhance the dental implant surface and to provide additional osteoinductive and antibacterial properties, plasma electrolytic oxidation of a pure Ti was performed using a nitrilotriacetic acid (NTA)-based Ag nanoparticles (AgNP)-loaded calcium–phosphate...
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Reactive extrusion of bio-based polymer blends and composites – Current trends and future developments
PublikacjaReactive extrusion is a cost-effective and environmentally-friendly method to produce new materials with enhanced performance properties. At present, reactive extrusion allows in-situ polymerization, modification/functionalization of polymers or chemical bonding of two (or more) immiscible phases, which can be carried out on commonly used extrusion lines. Although reactive extrusion has been known for many years, its application...
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EVALUATION OF 3D MODEL OF REBAR FOR QUANTITATIVE PARAMETERS
PublikacjaThe construction industry practices and processes are evolving constantly, and with the emergence of Industry 4.0, the use of technologies is expanding. Construction progress monitoring is an essential project lifecycle process; project success and timely completion are linked with effective progress monitoring operations and adopted tools. In the domain of automated construction progress monitoring, 3D modeling techniques have...
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Nitrofurazone Removal from Water Enhanced by Coupling Photocatalysis and Biodegradation
Publikacja(1) Background: Environmental contamination with antibiotics is particularly serious because the usual methods used in wastewater treatment plants turn out to be insufficient or ineffective. An interesting idea is to support natural biodegradation processes with physicochemical methods as well as with bioaugmentation with efficient microbial degraders. Hence, the aim of our study is evaluation of the effectiveness of different...
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Persistent homology as a new method of the assessment of heart rate variability
PublikacjaHeart rate variability (hrv) is a physiological phenomenon of the variation in the length of the time interval between consecutive heartbeats. In many cases it could be an indicator of the development of pathological states. The classical approach to the analysis of hrv includes time domain methods and frequency domain methods. However, attempts are still being made to define new and more effective hrv assessment tools. Persistent...
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Preparation and characterization of asphaltene based adsorbents for gas-solid adsorption systems
PublikacjaThe dissertation presents results of the experimental research on asphaltene-based adsorbents (support coated with asphaltene layer) for gas-solid adsorption systems, with special reference to volatile organic compounds (VOCs) removal from gas streams. Analysis of gas adsorption properties revealed that asphaltenes isolated from oxidized bitumen have strong affinity toward VOCs. Interactions with target gas molecules, and selectivity...
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Multimodal analysis of traction forces and the temperature dynamics of living cells with a diamond-embedded substrate
PublikacjaCells and tissues are constantly exposed to chemical and physical signals that regulate physiological and pathological processes. This study explores the integration of two biophysical methods: traction force microscopy (TFM) and optically detected magnetic resonance (ODMR) to concurrently assess cellular traction forces and the local relative temperature. We present a novel elastic substrate with embedded nitrogen-vacancy microdiamonds...
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Sea bottom structure investigation by means of acoustic methods
PublikacjaThe main aim of the paper is the result of experimental investigations of the seabed in the Gulf of Gdańsk arried out using parametric echosounder as a main measuring tool. Examination of the surface's upper layer of the seabed, especially is acoustic properties, reflecting most often transsmision and reflection properties of the incident elastic wave, could be a valuable material for determination of the stratification, and the...
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Analytical Buckling of FG Nanobeams on The Basis of A New One Variable First-Order Shear Deformation Beam Theory
PublikacjaIn this work, buckling analysis of functionally graded (FG) nanobeams based on a new refined beam theory has been analyzed. The beam is modeled as an elastic beam subjected to unidirectional compressive loads. To achieve this aim, the new obtained beam theory has only one variable which lead to one equation similar to Euler beam theory and also is free of any shear correction factor. The...
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Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublikacjaPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
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INFLUENCE OF PRESERVATIVE ON THE TENSILE STRENGTH OF THE TISSUE OF PORCINE CIRCULATORY SYSTEM
PublikacjaCurrently one of the leading causes of death worldwide is heart diseases which include calcification of heart valves and vascular aneurysm. There are many biomaterials that can substitute pathologically altered tissue, however, none of them is as perfect as native tissue. Currently, scientists are looking for new biomaterials that can be successfully implanted without exposing the patient to reoperation. Each material introduced...