Search results for: THIN STRUCTURES
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Application of linear buckling sensitivity analysis to economic design of cylindrical steel silos composed of corrugated sheets and columns
PublicationThe paper deals with global stability of steel cylindrical silos composed of corrugated walls and vertical columns with loads imposed by a bulk solid following Eurocode 1. The optimum silo design with respect to the steel weight was based on a sensitivity analysis method. The changes of silo column profiles at each design step were performed by means of influence lines for the buckling load factor due to the unit column bending...
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Determination of heavy metals in eyeshadows from China
PublicationPersonal care products and cosmetics are used daily by many people, causing local exposure to certain chemical substances through the application directly inside the oral cavity, on the skin, lips, eyes, and mucosa. Eyeshadows are among the most commonly used types of cosmetics. According to scientifc reports, they may contain heavy metals, especially in non-original products. The exposure to said heavy metals may cause local skin...
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Enhancing electrochemical properties of an ITO-coated lossy-mode resonance optical fiber sensor by electrodeposition of PEDOT:PSS
PublicationA sensor working in multiple domains may offer enhanced information about the properties of an investigated analyte, including those containing biological species. It has already been shown that a dual-domain sensing capability, i.e., in optical and electrochemical domains, can be offered by lossy-mode resonance (LMR) sensors based on indium-tin-oxide (ITO) thin film. The spectral response of the LMR sensors depends on the refractive...
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The electrochemical determination of isatin at nanocrystalline boron-doped diamond electrodes: stress monitoring of animals
PublicationUltra-thin nanocrystalline boron-doped diamond electrodes (B:NCD) were used for the electrochemical determination of isatin in dog urine samples using cyclic voltammetry and square wave voltammetry in a phosphate buffer saline, pH = 7.2. No additional modification or pretreatment of the electrode surface was required in this approach, being of high importance for the facile detection procedure. The increase of the peak current...
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Processing of Ce0.8Gd0.2O2-δ barrier layers for solid oxide cells: The effect of preparation method and thickness on the interdiffusion and electrochemical performance
PublicationCe0.8Gd0.2O1.9 (CGO) barrier layers are required to mitigate the chemical reactions between Sr-containing oxygen electrode materials and Zr-based oxygen ion conductors in high-temperature solid oxide cells. Barrier layers produced by different methods were studied in this work. As a reference, a cell with no barrier layer was measured. The application of the powder-processed barrier layers, considerably increases the performance....
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Surface and interfacial anti-plane waves in micropolar solids with surface energy
PublicationIn this work, the propagation behaviour of a surface wave in a micropolar elastic half-space with surface strain and kinetic energies localized at the surface and the propagation behaviour of an interfacial anti-plane wave between two micropolar elastic half-spaces with interfacial strain and kinetic energies localized at the interface have been studied. The Gurtin–Murdoch model has been adopted for surface and interfacial elasticity....
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Experimental research of the effect of face milling strategy on the flatness deviations
PublicationIn this paper the dependencies between face milling strategy of EN AW6082-T6 aluminum alloy samples, with difference thicknesses (6, 8, and 12 mm) and two cold rolling directions, and flatness deviations were presented. Three strategies of milling included different proportions of material removed from both sides of the plates. This approach allowed to control the proportions of residual surface stresses on both sides of the specimens,...
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Microscale diamond protection for a ZnO coated fiber optic sensor
PublicationFiber optic sensors are widely used in environmental, biological and chemical sensing. Due to the demanding environmental conditions in which they can be used, there is a risk of damaging the sensor measurement head placed in the measuring field. Sensors using nanolayers deposited upon the fiber structure are particularly vulnerable to damage. A thin film placed on the surface of the fiber end-face can be prone to mechanical damage...
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Local structural and chemical ordering of nanosized Pt(3±δ)Co probed by multiple-scattering x-ray absorption spectroscopy
PublicationThis work reports a detailed investigation of the local structure and chemical disorder of a Pt(3±δ)Co thin film and Pt(3±δ)Co nanoparticles. We have used a combination of techniques including x-ray absorption spectroscopy (XAS), x-ray diffraction (XRD), and high-resolution transmission electron microscopy (TEM). The important effect of chemical ordering on pair and three-atom configurations has been studied using computer simulations...
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Estimation of fracture toughness and shear yield stress of orthotropic materials in cutting with rotating tools
PublicationThe cutting force is an energetic effect of splitting material, and might be considered from a point of view of modern fracture mechanics. Forecasting of the shear plane angle in cutting broaden possibilities for modelling of the cutting process even for thin uncut chips. Such mathematical model has been developed here for description of the orthotropic materials’ cutting on the base of fracture theory, and includes work of separation...
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The influence of photointercalaction and photochromism effects on the photocatalytic properties of electrochemically obtained maze-like MoO3 microstructures
PublicationMolybdenum oxide (α-MoO3) thin films with oriented crystalline facets were synthesised by anodization of Mo foils. The obtained samples were exposed to UV–Vis illumination in aqueous electrolytes providing different cations. The morphology and structure of modified samples were investigated. The effect of photointercalated alkali metal cations (Li+, Na+, K+) on optical and structural properties was studied using UV–vis and Raman...
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Functionalization of indium-tin-oxide electrodes by laser-nanostructured gold thin films for biosensing applications
Publicationof a relatively large area formed by pulsed laser nanostructuring of thin gold films arereported and discussed. The SEM inspection of modified electrodes reveals the presence of the nearlyspherical and disc-shaped particles of dimensions in the range of 40–120 nm. The NP-array geometry canbe controlled by selection of the laser processing conditions. It is shown that particle size and packingdensity of the array are important factors...
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Electrocatalytic oxidation of methanol, ethylene glycol and glycerine in alkaline media on TiO2 nanotubes decorated with AuCu nanoparticles for an application in fuel cells
PublicationIn this work, we present the catalytic and photocatalytic activity of AuCu nanostructures obtained on TiO2 nanotubes toward methanol, ethylene glycol and glycerine oxidation. The electrode material is prepared by anodization of Ti foil, thin AuCu layer sputtering and rapid thermal treatment under argon atmosphere. Scanning electron microscopy images confirmed the presence of ordered tubular architecture of TiO2 as well as nanoparticles...
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Influence of alkali metal cations on the photoactivity of crystalline and exfoliated amorphous WO3 – photointercalation phenomenon
PublicationIn order to investigate the effect of photointercalation on photoelectrochemical properties, two types of WO3-based photoanodes, bulk and exfoliated have been prepared and investigated. An aqueous exfoliation method is introduced for the simple fabrication of amorphous and hydrated WO3 nanomaterial using commercial bulk WO3 precursor. The comparison of obtained material with bulk WO3 was performed using Raman, UV–vis, and XPS as...
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The bismuth vanadate thin layers modified by cobalt hexacyanocobaltate as visible-light active photoanodes for photoelectrochemical water oxidation
PublicationBismuth vanadate thin films deposited using the pulsed laser deposition technique were modified using cobalt hexacyanocobaltate (Cohcc). The 2-step method of Cohcc nanocubes preparation was applied: i) metallic cobalt deposition and ii) cobalt electrooxidation in Co(CN)63− containing electrolyte. The presence of CN stretching vibrations was confirmed by Raman spectroscopy. The energy band gap was equal to 2.5 eV and was estimated...
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Surface Roughness Evaluation in Thin EN AW-6086-T6 Alloy Plates after Face Milling Process with Different Strategies
PublicationLightweight alloys made from aluminium are used to manufacture cars, trains and planes. The main parts most often manufactured from thin sheets requiring the use of milling in the manufacturing process are front panels for control systems, housing parts for electrical and electronic components. As a result of the final phase of the manufacturing process, cold rolling, residual stresses remain in the surface layers, which can influence...
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Optoelectronic system for monitoring of thin diamond layers growth
PublicationDevelopment of the optoelectronic system for monitoring of diamond/DLC (Diamond-Like-Carbon) thin films growth during mu PA ECR CVD (Microwave Plasma Assisted Electron Cyclotron Resonance Chemical Vapour Deposition) process is described. The multi-point Optical Emission Spectroscopy (OES) and Raman spectroscopy were employed as non-invasive optoelectronic tools. Dissociation of H-2 molecules, excitation and ionization of hydrogen...
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Oriented Gaussian beams for high-accuracy computation with accuracy control of X-ray propagation through a multi-lens system
PublicationA highly accurate method for calculating X-ray propagation is developed. Within this approach, the propagating wave is represented as a superposition of oriented Gaussian beams. The direction of wave propagation in each Gaussian beam agrees with the local direction of propagation of the X-ray wavefront. When calculating the propagation of X-ray waves through lenses, the thin lens approximation is applied. In this approximation,...
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On the geometrically nonlinear vibration of a piezo-flexomagnetic nanotube
PublicationIn order to describe the behavior of thin elements used in MEMS and NEMS, it is essential to study a nonlinear free vibration of nanotubes under complicated external fields such as magnetic environment. In this regard, the magnetic force applied to the conductive nanotube with piezo-flexomagnetic elastic wall is considered. By the inclusion of Euler-Bernoulli beam and using Hamilton’s principle, the equations governing the system...
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Influence of the abrasive grain trajectory on the machining of thin-walled cylinder liners of internal combustion engines with variable kinematics of honing
PublicationGładzenie ze zmienną kinematyką posiada szereg zalet w porówna-niu do tradycyjnego gładzenia [1-19], takie jak: mniejsze zużycie na-rzędzia [12, 13], niższa temperatura obróbki [13], lepsza jakość po-wierzchni [12, 13] oraz mniejsza odchyłka walcowości [13]. W arty-kule omówiono zalety zmiennej kinematyki gładzenia. Można zało-żyć, że gładzenia ze zmienną kinematyką „VH” zostanie wdrożone wkrótce w przemyśle, np. w produkcji elementów...
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An improved scalable method of isolating asphaltenes
PublicationA new, improved and scalable procedure of asphaltene fraction isolation is presented and compared to standard test methods. The new procedure uses 1:40 feedstock to solvent (n-heptane) ratio (g/mL), filtration through a cellulosic thimble and extensive washing in a Soxhlet type extractor. The group type composition and purity of the asphaltene fractions have been examined using thin-layer chromatography with flame-ionization detection....
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Organic semiconductor rubrene thin films deposited by pulsed laser evaporation of solidified solutions
PublicationOrganic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm2(V·s)-1. However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic...
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Failure mode prediction for composite structural insulated panels with MgO board facings
PublicationSandwich panels are readily used in civil engineering due to their high strength to weight ratio and the ease and speed of assembly. The idea of a sandwich section is to combine thin and durable facings with a light-weight core and the choice of materials used allows obtaining the desired behaviour. Panels in consideration consist of MgO (magnesium oxide) board facings and expanded polystyrene core and are characterized by immunity...
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Heat transfer characteristics of hybrid microjet – Microchannel cooling module
PublicationThe paper presents experimental investigation of heat transfer intensification in a microjet–microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was...
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Investigation of the laser generated ablation plasma plume dynamics and plasma plume sound wave dynamics
PublicationWe investigated the dynamics of laser generated ablation plasma plume expanding in ambient air and dynamics of the sound wave generated by the expanding plasma. The ablation plasma plume was generated during nanosecond laser micromachining of the thin metal foil. The time-resolved images of the expanding plasma plume and sound wave were captured at several nanosecond intervals. Using captured images the expansion rate of the plasma...
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Surface Dielectric Barrier Discharge Plasma Actuators
PublicationThis paper presents a part of the works conducted in the Plasmaero European project (task 1.1) on surface dielectric barrier discharge actuators applied to airflow control. The study is divided into several parts. In the first part, the goal is to enhance the electric wind produced by a typical single DBD actuator by optimization of the active electrode shape. For instance, the use of a thin wire instead of a plate air-exposed...
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Ordered TiO2 nanotubes: the effect of preparation parameters on the photocatalytic activity in air purification process
PublicationVertically ordered TiO2 nanotube arrays were synthesized by anodic oxidation of titanium foil in glycerol, ethylene glycol and water-based electrolytes. The effect of electrolyte composition, anodization voltage, ultrasonic treatment and calcination time on the morphology of the resulting thin films, as well as on their photocatalytic activity in toluene removal, used as a model volatile organic compound, was investigated. Toluene,...
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Recycling of photovoltaic modules - legal status, technology, market prospects
PublicationThe increase in the number of manufactured and installed photovoltaic modules and the growing concern about the insufficient supply of pure silicon imply the need to take action to develop infrastructure for recycling PV modules. The article presents a multifaceted analysis of the current state of development of the photovoltaic module recycling sector from a global and national perspective. The essence of the issue was introduced...
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Anti-plane shear waves in an elastic strip rigidly attached to an elastic half-space
PublicationWe consider the anti-plane shear waves in a domain consisting of an infinite layer with a thin coating lying on an elastic half-space. The elastic properties of the coating, layer, and half-space are assumed to be different. On the free upper surface we assume the compatibility condition within the Gurtin–Murdoch surface elasticity, whereas at the plane interface we consider perfect contact. For this problem there exist two possible...
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Fatigue fracture surface metrology of thin-walled tubular austenitic steel specimens after asynchronous loadings
PublicationThis paper aims to study the effect of asynchronous axial-torsional strain-controlled loading histories on fracture surface behavior of thin-walled tubular X5CrNi18-10 (304/304L) austenitic steel specimens. Tests under pure axial loading and pure torsional loading are also conducted to better segregate the effect of multiaxiality. The fractures surface topographies were examined through the profiles over the entire surface with...
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Effect of double thermal and electrochemical oxidation on titanium alloys for medical applications
PublicationThe research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis,...
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The buckling analysis of a cold-formed steel C-sectional column resting on an elastic foundation
PublicationThe paper is focused on stability analysis of different models of steel cold-formed C-section column. The analysed element may be applied as a primary load-bearing member in steel trusses or silo columns. The column can be used as a support for a wall of roof plates made of corrugated sheets. The wall sheeting that restrains the column against buckling may be considered as an elastic foundation. Due to the design solutions the...
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Selected concentration techniques for gas chromatographic analysis of environmental samples
PublicationThe paper describes the role and tasks of environmental analysis and monitoring. It emphasises the leading role played by gas chromatography, especially when coupled with suitable sample preparation. This is demonstrated by some literature evidence and mainly by the author's original work on the design of sample preparation apparatus and development of GC-based methods of determination of a wide variety of organic pollutants in...
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A novel architecture for e-learning knowledge assessment systems
PublicationAbstract. In this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture,while well suited for didactic content distribution systems is ill-suited for knowledge assessment...
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Analytical methodologies for determination of artificial sweeteners in foodstuffs- a review
PublicationArtificial high-intensity sweeteners are more and more frequently used for food production. Food industry tends to highlight beneficial aspects of their use, such as tooth-friendliness, rising-up quality of life of those suffering from different forms of diabetes and possibility of weight control without sacrificing favorite unhealthy drinks or snacks. On the other hand some of the consumers are deeply concerned about safety of...
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Variable Temperature Spectroscopic Ellipsometry as a Tool for Insight into the Optical Order in the P3HT:PC70BM and PC70BM Layers
PublicationTwo combined ellipsometric techniques—variable angle spectroscopic ellipsometry (VASE) and variable temperature spectroscopic ellipsometry (VTSE)—were used as tools to study the surface order and dielectric properties of thin films of a poly(3-hexylthiophene-2,5-diyl) (P3HT) mixture with a fullerene derivative (6,6-phenyl-C71-butyric acid methyl ester) (PC70BM). Under the influence of annealing, a layer of the ordered PC70BM...
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A novel architecture for e-learning knowledge assessment systems
PublicationIn this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture, while well suited for didactic content distribution systems is ill-suited for knowledge assessment products....
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A novel architecture for e-learning knowledge assessment systems
PublicationIn this paper we propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. Our research proved that such architecture, while well suited for didactic content distribution systems is ill-suited for knowledge assessment products....
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Influence of Fragment Size on the Time and Temperature of Ethylene Vinyl Acetate Lamination Decomposition in the Photovoltaic Module Recycling Process
PublicationPhotovoltaics is a commercially available and reliable technology with significant potential for long-term growth in nearly all global regions. Several research institutes and companies are working on recycling concepts for thin film modules and modules with crystalline cells. The establishment of recycling and reuse technologies appropriate and applicable to all photovoltaics (PV) modules is a key issue to be addressed as part...
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Surface effects of network materials based on strain gradient homogenized media
PublicationThe asymptotic homogenization of periodic network materials modeled as beam networks is pursued in this contribution, accounting for surface effects arising from the presence of a thin coating on the surface of the structural beam elements of the network. Cauchy and second gradient effective continua are considered and enhanced by the consideration of surface effects. The asymptotic homogenization technique is here extended to...
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Enhancement of the Magnetic Coupling in Exfoliated CrCl 3 Crystals Observed by Low‐Temperature Magnetic Force Microscopy and X‐ray Magnetic Circular Dichroism
PublicationMagnetic crystals formed by 2D layers interacting by weak van der Waals forces are currently a hot research topic. When these crystals are thinned to nanometric size, they can manifest strikingly different magnetic behavior compared to the bulk form. This can be the result of, for example, quantum electronic confinement effects, the presence of defects, or pinning of the crystallographic structure in metastable phases induced by...
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Electrochemical performance of thin free-standing boron-doped diamond nanosheet electrodes
PublicationIn the following work we describe preparation and the electrochemical performance of thin and free-standing heavy boron-doped diamond (BDD) nanosheets. The investigated foils were deposited on Ta substrate using microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Foils of two B-dopant densities were investigated, obtained on the base of 10 k and 20 k ppm [B]/[C] ratio in the gas admixture. The obtained foils...
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Thickness accuracy of sash gang sawing
PublicationThin lamellae, corresponding to the layer components of structural glued members, i.e. 2-ply or 3-ply glued parquet, can be manufactured in re-sawing operations of kiln-dried wood blocks. These must be prepared with high dimensional accuracy and adequate surface quality following specific technical requirements for lamellae thickness variations, especially in the upper layers of the glued composite parquet. The accuracy of oak...
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A Highly Scalable, Modular Architecture for Computer Aided Assessment e-Learning Systems
PublicationIn this chapter, the authors propose a novel e-learning system, dedicated strictly to knowledge assessment tasks. In its functioning it utilizes web-based technologies, but its design differs radically from currently popular e-learning solutions which rely mostly on thin-client architecture. The authors' research proved that such architecture, while well suited for didactic content distribution systems is ill-suited for knowledge...
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Loosely-Tied Distributed Architecture for Highly Scalable E-Learning System
PublicationVast majority of modern e-learning products are based on client-server architecture and utilization of web-based technologies (WBT). Such approach permits easy creation of e-learning systems that do not require a complex, operating system dependant client software. Unfortunately there are also drawbacks of such solution. Because of the majority of mechanisms are located on the server, its usage levels trend to build up quickly...
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New matrix-free reference material for ethene in the form of optical fibres
PublicationReference materials are indispensable in the qualitycontrol and quality assurance of analytical measurements. Onenovel approach to the generation of standard gaseous mixturesof toxic, reactive, volatile, labile, and malodorous substancesinvolves thermal decomposition or rearrangement, under definedtemperature conditions, of compounds immobilized, bychemical bonding, on the surface of an appropriate carrier torelease specific amounts...
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Innovative system for energy collection and management integrated within a photovoltaic module
PublicationThe dynamic development of battery technology and design based on the flow of lithium ions, mainly driven by the needs of the automotive industry, leads to the conclusion that these batteries are becoming a more viable alternative to traditional lead-acid batteries. Their use is driven by the ability to quickly charge and discharge, a higher durability, maintenance-free operation, much smaller dimensions and lighter weight. The...
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Enhanced photoelectrochemical performance of inorganic-organic hybrid consisting of BiVO4 and PEDOT:PSS
PublicationThe PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) was electrodeposited on a thin layer of bismuth vanadate (BiVO 4 ) prepared using the pulsed laser deposition technique onto FTO. The inorganic-organic junction was characterized by Raman spectroscopy, UV-Vis spectroscopy and sc anning electron microscopy. Chronoamperometry curves, recorded under simulated solar light illumination,...
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Heat transfer characteristics of hybrid microjet -microchannel cooling module
PublicationThe paper presents the experimental investigation of heat transfer intensification in a microjet- microchannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper...
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Dome over the Gdynia seaport building
PublicationThe paper presents the description of structure and the selected problems of the technical condition, as well as the strength analysis of the thin-walled reinforced concrete shell which has been making a covering of the main hall of the Gdynia Seaport Building through the last 80 years. The rectangle projection of four single curvature shells of the dome was shaped out of mutual perpendicular intersection of two cylindrical shells. The...