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Search results for: OPTICAL SCANNING
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A brief note on monotonic and fatigue fracture events investigation of thin-walled tubular austenitic steel specimens via fracture surface topography analysis (FRASTA)
PublicationThe main objective of this short communication is to show the fracture progression in each loading case and complement knowledge about fracture mechanisms underpinning the tensile and fatigue performance of thin-walled tubes. For this purpose, the fracture surface topography analysis (FRASTA) method was used in the thin-walled tubular austenitic stainless-steel specimens. Two cases were analyzed: monotonic tension, and uniaxial...
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Three-Dimensional Fractography for Conventional and Additive Manufactured Steels After Bending-Torsion Fatigue
PublicationIn this study, fracture surface topography parameters were measured to investigate the effects of multiaxial loading. In order to assess the metrological aspects of fracture for notched specimens made of high-strength steels processed by both conventional and additively manufacturing (AM) techniques, an optical surface profilometer was used. Three bending moment to torsion moment ratios (B/T) were studied, i.e. 2, 1 and 2/3. The...
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Structure and optical parameters of Eu doped tellurium oxide thin films prepared by reactive magnetron sputtering method
PublicationIn this work the structural properties and photoluminescence of tellurium dioxide thin films doped by europium were described. Thin films were deposited by magnetron sputtering method and simultaneously heated at 200 °C. Presence of Eu ions and their valence states was confirmed by X-ray photoemission spectroscopy measurements. The structure of the films as well as the influence of europium dopant on crystalline structure of the...
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Design and implementation of GEPON architecture in laboratory testbed
PublicationThis paper presents a proposition of GEPON architecture for the didactic purpose. The GEPON architecture is implemented in access networks laboratory testbed. The paper includes a brief description of GEPON standardization, a description of laboratory GEPON equipment architecture and a short presentation of proposed laboratory exercises. The exemplary performance results are included.The proposition of GEPON architecture testbed...
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Examination method of the effect of the incidence angle of laser beam on distance measurement accuracy to surfaces with different colour and roughness
PublicationInterest in the influence of the incidence angle of a laser beam to distance measurements can be seen in many areas of science and technology: geodesy, glaciology, archaeology, machine automation, and others. This paper presents results of measurements of the effect of the incidence angle of a laser beam to distance measurements to the surfaces of different colour and roughness by Topcon's electro-optical total station with an...
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Measuring the density of DNA films using ultraviolet-visible interferometry
PublicationIn order to determine a proper value for the density of dry DNA films we have used a method based upon the measurement of interference effects in transmission spectra of thin DNA layers. Our results show that the methodology is effective and the density of DNA in this state, 1.407 g/cm3, is much lower than the commonly used 1.7 g/cm3. Obtaining accurate values for the DNA film density will allow the optical constants for DNA to...
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Investigation of photothermolysis therapy of human skin diseases using optical phantoms
PublicationDermatological diseases, such as neurofibroma (Recklinghausen disease) or hemangiomas can be efficiently treated using photothermolysis from laser irradiation. We have utilized a developed 975 nm fiber diode laser as a low-cost alternative over common Nd:YAG lasers. This paper describes the investigations of interaction of 975 nm diode laser radiation-pulses with optical skin phantoms which were designed and manufactured in our...
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Linear antenna microwave chemical vapour deposition of diamond films on long-period fiber gratings for bio-sensing applications
PublicationThe growth processes of nanocrystalline diamond (NCD) thin films on fused silica optical fibers with UV-induced long-period gratings (LPGs) were investigated with regard to biosensing applications. The films were deposited using a linear antenna microwave plasma enhanced chemical vapor deposition system, which allows for the growth of diamond at temperatures below 350°C. The films exhibited a high refractive index n = 2.32, as...
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Analysis of the structure of the atomized fuel spray with marine diesel engine injector in the early stage of injection
PublicationThis paper presents the results of the experimental research of the atomized fuel spray with the marine diesel engine injector in the constant volume chamber. The specificity of the phenomena occurring in the marine engine cylinder was the reason to use the optical visualisation method in the studies – the Mie scattering technique. This work presents an analysis of the influence of different geometry of outlet orifice and opening...
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The impact of surface slope and calculation resolution on the fractal dimension for fractures of steels after bending-torsion fatigue
PublicationThe article presents the results of the fractal dimension measurements on the fatigue fracture surfaces of 10HNAP and S355J2 steels specimens after combined bending-torsion fatigue. For smooth and ring-notched specimens, three loading conditions were analyzed: (1) bending; (2) bending-torsion; and (3) torsion fatigue. Post-failure surface topography measurements were carried out on the entire fracture surfaces using an optical...
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Non-invasive blood glucose monitoring with Raman spectroscopy: prospects for device miniaturization
PublicationThe number of patients with diabetes has reached over 350 million, and still continues to increase. The need for regular blood glucose monitoring sparks the interest in the development of modern detection technologies. One of those methods, which allows for noninvasive measurements, is Raman spectroscopy. The ability of infrared light to penetrate deep into tissues allows for obtaining measurements through the skin without its...
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Heat capacities and thermodynamic properties of antimony substituted lanthanum orthoniobates
PublicationThe results of heat capacity measurements for the lanthanum orthoniobate substituted with 10, 20 and 30 mol% of antimony (LaNb0.9Sb0.1O4, LaNb0.8Sb0.2O4 and LaNb0.7Sb0.3O4) are presented and discussed. Temperature dependence of low temperature heat capacity was analyzed within the Debye and Einstein models. The Debye temperature decreased, whereas the Einstein temperature increased with antimony content. The decrease of the Debye...
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Semi complex navigation with an active optical gesture sensor
PublicationThis paper presents the methods of diversified touchless interactions between a user and a mobile platform utilizing the optical gesture sensor. The sensor uses 8 photodiodes to measure the reflected light in the active mode (using embedded LEDs) or it measures shadows caused by fingers in the passive mode. Several algorithms were implemented: automatic mode switching, adaptive illumination level compensation, resolution improvements...
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π-Conjugated Donor-acceptor Polyelectrolytes: Toward Artificial Photosynthesis
PublicationGreat advances have been made in the development of conjugated polyelectrolytes (CPEs), which provide tunable properties including water solubility and processability, main-chain exciton and charge transport, variable energy light absorption and fluorescence, non-covalent interactions, and formation of tertiary structures via self-assembly.[1] These characteristics allow CPEs to be considered for use in various optoelectronic applications,...
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Ultrashort Opposite Directed Pulses Dynamics with Kerr Effect and Polarization Account
PublicationWe present the application of projection operator methods to solving the problem of the propagation and interaction of short optical pulses of different polarizations and directions in a nonlinear dispersive medium. We restrict ourselves by the caseof one-dimensional theory, taking into account material dispersion and Kerr nonlinearity. The construction of operators is delivered in two variants: for the Cauchy problem and for the...
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Measurements of ASON/GMPLS connection control layer performance according to the ETSI methodology
PublicationMeasurements of performance have always been crucial for evaluation of telecommunication systems, especially for implementation of network control elements responsible for connection handling which regards to bandwidth reservation, modification and release. That problem also arises in Automatically Switched Optical Network/Generalized Multiprotocol Label Switching (ASON/GMLPS) architecture, which is considered as one of the components...
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RAMAN DIAGNOSTICS OF CVD DIAMOND GROWTH
PublicationDevelopment of Raman spectroscopic system for diagnostics of growth of diamond and BDD (Boron- Doped-Diamond) thin films during μPA CVD (Microwave Plasma Assisted Chemical Vapour Deposition) process is described. Raman studies of such films were carried out as in-situ monitoring of film deposition as ex-situ measurements conducted for a sample outside the reaction vessel after manufacturing process. Modular system for the in-situ...
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Sprzętowa realizacja algorytmu przepływu optycznego w układzie FPGA
PublicationW pracy przedstawiono efektywną procedurę uproszczenia algorytmu typu optical flow (OF) oraz jego realizacje sprzętową w technologii układów FPGA. Zmodyfikowany algorytm bazuje na lokalnym dopasowaniu (korelacji) podobszarów ramki aktualnej i poprzedniej. W strukturze opracowanego algorytmu wykorzystano 1-wymiarową reprezentację podobszarów oraz zapis intensywności w kodzie Gray'a, co zmniejszyło złożoność obliczeniową przy zachowaniu...
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Efficient signal processing in spectroscopic optical coherence tomography
PublicationSpectroscopic optical coherence tomography (SOCT) is an extension of a standard OCT technique, which allows to obtain depth-resolved, spectroscopic information on the examined sample. It can be used as a source of additional contrast in OCT images e.g. by encoding certain features of the light spectrum into the hue of the image pixels. However, SOCT require computation of time-frequency distributions of each OCT A-scan, what is...
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Use of optical skin phantoms for preclinical evaluation of laser efficiency for skin lesion therapy
PublicationSkin lesions are commonly treated using laser heating. However, the introduction of new devices into clinical practice requires evaluation of their performance. This study presents the application of optical phantoms for assessment of a newly developed 975-nm pulsed diode laser system for dermatological purposes. Such phantoms closely mimic the absorption and scattering of real human skin (although not precisely in relation to...
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Facial emotion recognition using depth data
PublicationIn this paper an original approach is presented for facial expression and emotion recognition based only on depth channel from Microsoft Kinect sensor. The emotional user model contains nine emotions including the neutral one. The proposed recognition algorithm uses local movements detection within the face area in order to recognize actual facial expression. This approach has been validated on Facial Expressions and Emotions Database...
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Leveraging spatio-temporal features for joint deblurring and segmentation of instruments in dental video microscopy
PublicationIn dentistry, microscopes have become indispensable optical devices for high-quality treatment and micro-invasive surgery, especially in the field of endodontics. Recent machine vision advances enable more advanced, real-time applications including but not limited to dental video deblurring and workflow analysis through relevant metadata obtained by instrument motion trajectories. To this end, the proposed work addresses dental...
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Microsphere structure application for supercapacitor in situ temperature monitoring
PublicationConstant, real-time temperature monitoring of the supercapacitors for efficient energy usage is in high demand and seems to be crucial for further development of those elements. A fiber-optic sensor can be an effective optoelectronic device dedicated for in-situ temperature monitoring of supercapacitors. In this work, the application of the fiber-optic microstrucutre with thin zinc oxide (ZnO) coating fabricated in the atomic layer...
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Detection of petroleum products using optical coherence tomography
PublicationIn this work, we present a novel method developed for the analysis of the properties of thin layers for detecting petroleum products on a water surface using a commercially available optical coherence tomography (OCT) system. The spectral density analysis of the signal from a spectroscopic OCT (S-OCT) enables us to perform the precision calculation of the thin layer thickness and other properties like homogeneity, and dispersion,...
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Influence of plasmon resonance on the luminescence of titanium dioxide thin films doped with rare earth ions
PublicationIn this work the study of the optical properties of europium doped titanium dioxide thin films (TiO2:Eu) enhanced by gold plasmonic nanostructures are presented. Plasmonic platforms were manufactured by thermal annealing of thin film of Au, deposited on a Corning glass substrate. As a result of thermal treatment, gold spherical nanostructures with average dimensions of 50 nm were obtained. Luminescent TiO2:Eu film was deposited...
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Imaging polarimeter with high-accuracy measuring principles in crystal optics
PublicationAn imaging polarimeter based on the principles of high-accuracy polarimetry well known in crystal optics is proposed. The application of scientific digital cameras for performance light measurements leads to precise data on polarizers quality, i.e., maps of extinction ratio and transmission axis. Processing of numerous images, acquired at various settings in the polarizer-sample-analyser system, allows to determine the two-dimensional...
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Microfluidic devices for photo-and spectroelectrochemical applications
PublicationThe review presents recent developments in electrochemical devices for photo- and spectroelectrochemical investigations, with the emphasis on miniaturization (i.e., nanointerdigitated complementary metal-oxide-semiconductor devices, micro- and nano-porous silicon membranes or microoptoelectromechanical systems), silica glass/microreactors (i.e., plasmonic, Raman spectroscopy or optical microcavities) or polymer-based devices (i.e.,...
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Analysis of luminance distribution uniformity in CAVE-type virtual reality systems
PublicationIn recent years, many scientific and industrial centers in the world developed a virtual reality systems or laboratories. The effect of user “immersion” into virtual reality in such systems is largely dependent of optical properties of the system. In this paper, problems of luminance distribution uniformity in CAVE-type virtual reality systems are analyzed. For better characterization of CAVE luminance nonuniformity corner and...
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Does the low optical band gap of yellow Bi3YO6 guarantee the photocatalytical activity under visible light illumination?
PublicationBi3YO6, which is known as an ionic conductor, was tested here as an electrode and photoanode in contact with aqueous electrolytes. Bi3YO6 was deposited onto the Pt substrate and the such prepared electrode was polarized in various aqueous electrolytes. The optical energy band gap of the material equal to 1.89 eV was determined using the Kubelka-Munk function resulting from the UV-Vis spectrum (allowed indirect transition) and also...
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Fracture surface topography investigation and fatigue life assessment of notched austenitic steel specimens
PublicationThe objectives of this study were to investigate the fracture surface topography of X8CrNiS18-9 austenitic stainless-steel specimens for different loadings and notch radii and to supplement the knowledge about the fracture mechanisms for fatigue performance. Cases with three different values of the notch radius ρ and the stress amplitude σa were analysed. The fracture topographies were quantified by the areas over their entire...
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Analysis of the macrostructure of the fuel spray atomized with marine engine injector
PublicationOne of the main problem influencing the combustion process in the cylinder of the marine engine is an fuel spray phenomena. The parameters describing the shape of the fuel spray are named macro parameters. This article presents the research results of the macrostructure parameters of the fuel spray atomized with the marine engine injector. The research were carried out by optical visualization measurement method of Mie scattering....
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Chromogenic azomacrocycles with imidazole residue: Structure vs. properties
PublicationNew 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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Spectral reflectance and transmission modeling of multi-cavity Fabry-Pérot interferometer with ZnO thin films
PublicationIn this paper spectral reflectance and transmission of a low-coherence fiber-optic Fabry-Pérot interferometer with thin ZnO layers is analyzed using a multi-cavity approach. In the investigated setup two standard single-mode optical fibers (SMF-28) with thin ZnO films deposited on their end-faces form an extrinsic Fabry-Pérot interferometer with air cavity. Calculations of the spectral response of the interferometer were performed...
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The low coherence Fabry-Pérot interferometer with diamond and ZnO layers
PublicationThe authors present a fiber-optic Fabry-Pérot interferometer built with the application of diamond and zinc oxide (ZnO) thin layers. Thin ZnO films were deposited on the tip of a standard telecommunication single-mode optical fiber (SMF- 28) while the diamond layer was grown on the plate of silicon substrate. Investigated ZnO layers were fabricated by atomic layer deposition (ALD) and the diamond films were deposited using Microwave...
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The Ellenbogen's "Matter as Software" Concept for Quantum Computer Implementation: III. Selection of X@C60 Molecular Building Blocks (MBBs) for Tip-Based Nanofabrication (TBN) of Trapped Neutral Atom Quantum Computing Devices
PublicationThe selection of guest atoms X of X@C60 MBBs for TBN of trapped neutral atom quantum computing devices is reported. Assuming the all-optical quantum computing as a final target stage, the two criteria are most important: the charge q accumulated on the C60 host must be as low as possible, and the atom X must have one or more available excited states within the band falling into the low energy window of neutral C60 molecule electronic...
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Optical and chemical characterization of thin TiNx films deposited by DC-magnetron sputtering
PublicationThin titanium nitride (tinx) films were deposited on silicon substrates by means of a reactive dc-magnetron plasma. Layers were synthesized under various conditions of discharge power and nitrogen flows in two operation modes of the magnetron (the so-called "balanced" and "unbalanced" modes). The optical constants of the tinx films were investigated by spectroscopic ellipsometry (se). X-ray photoelectron spectroscopy (xps) was...
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Letters detection in the photograph
PublicationUrządzenie do lokalizacji i odczytu napisów z przeznaczeniem dla osób niewidomych może wykorzystywać standardowe systemy rozpoznawania znaków OCR (ang. Optical Character Recognition). Niestety ze względu na złożoność scen w terenie systemy takie nie potrafią analizować zdjęć bezpośrednio. Zdjęcia przed uruchomieniem systemu OCR wymagają przetworzenia polegającego na segmentacji i wyszukaniu segmentów podobnych do liter. Podejście...
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Design and implementation of an illumination system to mimic skyglow at ecosystem level in a large‐scale lake enclosure facility
PublicationLight pollution is an environmental stressor of global extent that is growing exponentially in area and intensity. Artificial skyglow, a form of light pollution with large range, is hypothesized to have environmental impact at ecosystem level. However, testing the impact of skyglow at large scales and in a controlled fashion under in situ conditions has remained elusive so far. Here we present the first experimental setup to mimic...
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Ln2(SeO3)2(SO4)(H2O)2 (Ln=Sm, Dy, Yb): A Mixed‐Ligand Pathway to New Lanthanide(III) Multifunctional Materials Featuring Nonlinear Optical and Magnetic Anisotropy Properties
PublicationBottom-up assembly of optically nonlinear and magnetically anisotropic lanthanide materials involving precisely placed spin carriers and optimized metal-ligand coordination offers a potential route to developing electronic architectures for coherent radiation generation and spin-based technologies, but the chemical design historically has been extremely hard to achieve. To address this, we developed a worthwhile avenue for creating...
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Influence of controlled crystallization and SrF2 content on the structure and properties of Eu3+ doped phosphate glasses
PublicationNew phosphate glasses and glass-ceramics P2O5–Bi2O3–K2O–Nb2O5-SrF2 doped with Eu were synthesized and studied in this work. The influence of the SrF2 content (0–15 mol%) and the parameters of the heat treatment on their structural and optical properties were investigated. For the above purpose, the structural characterization by FTIR spectroscopy and XRD measurements was carried out, which showed a significant effect of SrF2 on...
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Evaluation of Immobilization of Selected Peat-Isolated Yeast Strains of the Species Candida albicans and Candida subhashii on the Surface of Artificial Support Materials Used for Biotrickling Filtration
PublicationThe paper describes the process of n-butanol abatement by unicellular fungi, able to deplete n-butanol content in gas, by using n-butanol as source of carbon. Isolated and identified fungi species Candida albicans and Candida subhashii were subjected to a viability process via assimilation of carbon from hydrophilic and hydrophobic compounds. The isolates, which exhibited the ability to assimilate carbon, were immobilized on four...
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Optimization of Wireless Networks for Resilience to Adverse Weather Conditions
PublicationIn this chapter, we consider how adverse weather conditions such as rain or fog affect the performance of wireless networks, and how to optimize these networks so as to make them robust to these conditions. We first show how to analyze the weather conditions in order to make them useful for network optimization modelling. Using an example realistic network, we show how to optimize two types of wireless networks: free-space optical...
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Enhancement of fiber-optic low-coherence Fabry-Pérot interferometer with ZnO ALD films
PublicationIn this paper investigation of the enhanced fiber-optic low coherence Fabry-Pérot interferometer with zinc oxide (ZnO) film deposited by atomic layer deposition (ALD) was presented. Model of the interferometer, which was constructed of single-mode optical fiber with applied ZnO ALD films, was built. The interferometer was also examined by means of experiment. Measurements were performed for both reflective and transmission modes,...
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Folding‐upon‐repair DNA nanoswitches for monitoring DNA repair enzymes activity
PublicationWe demonstrate here a new class of DNA‐based nanoswitches that, upon enzymatic repair, could undergo a conformational change mechanism leading to a change in fluorescent signal. Such folding‐upon‐repair DNA nanoswitches are synthetic DNA sequences containing O6‐methyl‐guanine (O6‐MeG) nucleobases and labelled with a fluorophore/quencher optical pair. The nanoswitches are rationally designed so that only upon enzymatic demethylation...
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Methodology for the Correction of the Spatial Orientation Angles of the Unmanned Aerial Vehicle Using Real Time GNSS, a Shoreline Image and an Electronic Navigational Chart
PublicationUndoubtedly, Low-Altitude Unmanned Aerial Vehicles (UAVs) are becoming more common in marine applications. Equipped with a Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) receiver for highly accurate positioning, they perform camera and Light Detection and Ranging (LiDAR) measurements. Unfortunately, these measurements may still be subject to large errors-mainly due to the inaccuracy of measurement of the optical...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublicationThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublicationIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...
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Case Study of Old Steel Riveted Railway Truss Bridge: From Material Characterization to Structural Analysis
PublicationThe structural analysis of an old steel riveted railway truss bridge located over the Maruska River on the Działdowo – Olsztyn, Poland railway line is performed in this paper to check its behaviour under today’s railway loads. The mechanical properties of construction steel extracted from the old steel bridge are investigated by tensile tests, impact tests through the Charpy pendulum impact V-notch, and an optical emission spectrometer....
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Theoretical Design of the Molecular Structure of Bent-Core Mesogens with Large Second-Order Nonlinear Optical Properties
PublicationABSTRACT: The first hyperpolarizability of two series of moleculeswith bent-shaped structures has been calculated at the ab initio level.The two series consist of carboxyl derivatives for which somemolecules are known to exhibit banana phases and of their sulfinatehomologues that have not been synthesized yet. The final purpose isto reveal the relevance or not in synthesizing these latter molecules.The strategy is based on reporting...
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Call Control Evaluation in ASON/GMPLS Architecture
PublicationThe Automatically Switched Optical Network (ASON) utilizing Generalized Multi–Protocol Label Switching (GMPLS) protocols named as ASON/GMPLS is one of the propositions of Next Generation Network. The basic assumption of ASON control plane is a separation of call control from connection control. The control plane is divided into call control and connection control components. Presented work regards the problem of call control evaluation...