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Wyniki wyszukiwania dla: STEEL BOLTED JOINT
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Problems of Determination of Welding Angular Distortions of T-fillet Joints in Ship Hull Structures
PublikacjaShip hull structure elements are in majority joined by welding. Welding distortions can cause a lot of problems during the manufacturing process. In the literature it is proposed wide spectrum of suggestions for a correct estimation of welding deformation in particular angular deformation in the fillet welded T joint. In the work verification of selected methods is proposed basing upon of the results of the laboratory measurements....
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Receiver-side fingerprinting method based on quaternion sandwich product
PublikacjaIn this paper a new receiver-side fingerprinting method for color images is proposed. The proposed method belongs to the group of Joint Fingerprinting and Decryption (JFD) methods. Each component of the color image is represented as a point in 3D space, which is formed by 3 color channels. Encryption and fingerprinting can be interpreted as rotation, scaling and translation of these points. Calculations are performed using quaternion...
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Investigation of Continuous Wave Jamming in an IEEE 802.15.4 Network
PublikacjaThis paper presents how continuous wave jamming affects IEEE 802.15.4 network. To this end, an office-based measurement setup has been proposed. Within the measurement area, 25 nodes have been set up in order to create a IEEE 802.15.4 tree-based test network structure. A dedicated jamming device that generates and transmits a continuous wave signal has been developed. Several tests have been conducted and presented to demonstrate...
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Study of Nanohydroxyapatite Coatings Prepared by the Electrophoretic Deposition Method at Various Voltage and Time Parameters
PublikacjaThe aim of the work is to compare the properties of nanohydroxyapatite coatings obtained using the electrophoretic deposition method (EDP) at 10 V, 20 V, and 30 V, and with deposit times of 2 and 5 min. The primary sedimentation was used to minimize the risk of the formation of particle agglomerates on the sample surface. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy-Dispersive Spectroscopy...
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublikacjaHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Effect of Tool Positioning Factors on the Strength of Dissimilar Friction Stir Welded Joints of AA7075-T6 and AA6061-T6
PublikacjaFriction Stir Welding (FSW) is a solid-state bonding technique. There are many direct and indirect factors affecting the mechanical and microstructural properties of the FSW joints. Tool offset, tilt angle, and plunge depth are determinative tool positioning in the FSW process. Investigating the effect of these factors simultaneously with other parameters such as process speeds (rotational speed and translational speed) and tool...
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Roof over PGE Arena in Gdansk. Review of structure and monitoring system
PublikacjaThis paper presents general structural assumptions of the steel construction designed for a newfootball stadium to be built for UEFA Championship 2012 in the city of Gdańsk. The superstructureis founded directly on the modified abutment. The facade and the roof are collected from 82 steelgirders made of tube profiles. The girders are braced by circular beams and X tension rods. All thiscreates a quasi - dome covered by polycarbonate...
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Detection of impulsive disturbances in archive audio signals
PublikacjaIn this paper the problem of detection of impulsive disturbances in archive audio signals is considered. It is shown that semi-causal/noncausal solutions based on joint evaluation of signal prediction errors and leave-one-out signal interpolation errors, allow one to noticeably improve detection results compared to the prediction-only based solutions. The proposed approaches are evaluated on a set of clean audio signals contaminated...
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FEM simulations applied to the failure analysis of RC structure under the influence of municipal sewage pressure
PublikacjaThe paper discusses a failure mechanism of reinforced concrete (RC) structure with steel cover that failed under the influence of municipal sewage pressure. To explain the reasons of failure, in-situ measurements, laboratory experiments and comprehensive Finite Element Method (FEM) computations were performed. Non-destructive in-situ scanning tests were carried out to determine quantity and cover thickness of embedded reinforcement...
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TECHNOLOGIA RADIA PROGRAMOWALNEGO – SPRZĘT I OPROGRAMOWANIE
PublikacjaTechnologia radia programowalnego (ang. Software Defined Radio) jest nowoczesnym rozwiązaniem umożliwiającym realizację urządzeń pracujących w różnego rodzaju systemach łączności radiowej. W pracy zaprezentowano zagadnienia dotyczące koncepcji realizacji radia programowalnego. Zaprezentowano budowę dwóch przykładowych platform sprzętowych do realizacji radia programowalnego. Przedstawiono również architekturę oprogramowania stosowaną...
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Effets de variabilite d'adhesion et de viellissement en collage structural
PublikacjaDivers essais peuvent etre employes afin d'evaluer la resistance a la fracture des joints adhesifes. Generalement, ces essais sont symetriques: les substrats sont identiques. Nous avons utilise une version asymetrique, ou un adherend flexible est colle a aderend rigide. Nous discutons ici du comportement d'un joint d'adhesion variable. Des resultats assez surprenants font le sujet prinicpal de cet article.
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OPTICAL STRAIN MEASUREMENT OF CONCRETE VERSUS MANUAL EXTENSOMETER MEASUREMENT BASED ON THE TEST RC DEEP BEAM IN A COMPLEX STATE OF STRESS
PublikacjaThe purpose of this study is to compare the strain measurement techniques of concrete in R-C element subjected to the monotonic load up to the failure. In the analysis manual extensometer methods of measurements and the optical system ARAMIS for non-contact three-dimensional measurements of deformation was used. The test sample was a cantilever deep beam loaded throughout the depth which was a part of the reinforced concrete deep...
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Comparison of requirements for location, maintenance and removal of road advertising between polish and foreign regulations
PublikacjaThe article gives an overview of Polish and international formal and legal requirements for roadside advertising and the relevant road safety impacts. The analysis focussed on outdoor advertising life cycle consisting of three stages: location, operation and removal of advertising. Experience of road authorities from Australia (Queensland), Republic of South Africa and the United Kingdom was collected. The article is part of a...
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Porównanie nowych metod fingerprintingu i deszyfracji do zabezpieczania obrazów kolorowych
PublikacjaW artykule porównano nowe metody łącznego fingerprintingu i deszyfracji JFD (ang. Joint Fingerprinting and Decryption) dla obrazów kolorowych zaproponowane w rozprawie doktorskiej dr inż. Bartosza Czaplewskiego. Metody porównano z innymi metodami JFD znanymi z literatury. Metody zostały porównane w kontekście niezauważalności fingerprintów, odporności na szum, odporności na kompresję, odporności na ataki zmowy, oraz odporności...
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Stability and limit load analysis of a cold-formed channel section column
PublikacjaThe paper presents stability and limit load analysis of a steel column 1440 mm high of a cold-formed channel section, subjected to a combination of compression and bending. Experimental results were compared to the resistance of a code procedure and to the outcome of numerical non-linear analysis. Comparison was made of numerical solutions by means of static (Riks) and dynamic (Explicit and Implicit) methods. Perfectly elastic...
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Wet H2S corrosion and degradation of pipeline in amine regeneration system
PublikacjaThe paper presents the results of NDT examinations, metallographic tests and risk assessment of degradation related to corrosion of amine regeneration unit in a desulphurisation system. Intensive corrosion resulting from acid gases environment upon water condensation causes perforation of the pipeline. Detailed analysis reveals cracking related to the mechanism of wet H2S. Hydrogen penetration, resulting from the wet H2S process,...
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Implementacja pomierzonych imperfekcji geometrycznych powłokicylindrycznej do modelu obliczeniowego
PublikacjaThis paper presents the method of implementation of the geometrical imperfections used by the author during the experimental and numerical research into the load-carrying capacity of cylindrical steel shells subjected to uniform circumferential compression.
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Badania spawalności stali S460N w środowisku wodnym z wykorzystaniem próby Tekken
PublikacjaSpawanie w środowisku wodnym niesie ze sobą wiele problemów, wśród których najważniejszym jest skłonność stali do powstawania pęknięć zimnych. O ile w przypadku spawania na powietrzu istnieje wiele metod zapobiegania tym pęknięciom, o tyle pod wodą zastosowanie tych metod jest ograniczone. Z tego powodu konieczne jest określenie skłonności danego materiału do pękania zimnego. W pracy oceniono spawalność drobnoziarnistej...
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Viscous versus electromagnetic damping – amplification in a neighbourhood of a mechanism singular position
PublikacjaIn the paper, damping of vibrations are considered and compared in a mechanical and in a electromechanical system. In the system, a continuous beam is considered as the main vibrating element. The compared dissipations methods are based on: viscous dampers and DC generators. To increase the possible damping effectiveness, velocity amplification is proposed, i.e., a mechanism is introduced between the beam and the damping element....
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Alternative way of the main reinforcement anchorage in reinforced short cantilevers
PublikacjaThe results of the experimental investigation of the reinforced corbels and dapped end beams with steel studs were introduced in the work. The efficiency of this type of the reinforcement was compared with the typical reinforcenet applied in reinforced conctrete construcions.
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Investigation and operation problems of metal tanks in Poland
PublikacjaThe paper consists of three parts concerned with steel cylindrical, vertical tank for liquid fuel. In the first part the present trends in tank design and building in Poland are described. The main are: · reduction of environment contamination danger caused by tank leakage and hydrocarbons evaporation, · increasing capacity of new tanks (100000 m3 and more) due to economic factor - reduction of steel amount per m3 of storage capacity....
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Protective and Suppressing Electromagnetic Interference Properties of Epoxy Coatings Containing Nano-Sized NiZn Ferrites
PublikacjaNano-crystalline ferrites with the chemical formula NixZn(1−x)Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a co-precipitation method. The obtained ferrites were investigated by X-ray diffraction (XRD). The corrosion inhibiting behavior of nano-sized ferrites was tested using carbon steel samples and 10% aqueous ferrite extracts. Results were compared with previous data obtained for micro-sized ceramic ferrites....
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Wybrane aspekty modelowania uderzenia pojazdem dźwigara wiaduktu
PublikacjaW pracy przedstawiono różne zagadnienia związane z uderzeniem pojazdu w dźwigar wiaduktu. Omówiono wybór modelu obliczeniowego, na podstawie porównania wyników dla modelu dźwigara zespolonego, modelu dźwigara stalowego oraz modelu wiaduktu. Następnie opisano model dźwigara zespolonego zastosowany w analizie MES oraz metodę wyznaczania współczynników tłumienia Rayleigha. Symulację numeryczną uderzenia dźwigara wiaduktu przez koparkę...
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PRĄDY WYRÓWNAWCZE W UZIOMACH FUNDAMENTOWYCH I SZTUCZNYCH
PublikacjaW artykule omówiono zasady wykonywania uziomów fundamentowych i sztucznych. Przedstawiono wyniki pomiarów prądów w instalacji zawierającej stal zbrojeniową w fundamencie, połączoną z układem uziomu sztucznego w ziemi wykonanym z stali ocynkowanej.
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Investigation of behaviour of metal structures with polymer dampers under dynamic loads
PublikacjaA large number of accidents concerning structures subjected to dynamic loads have been recently observed. One of the examples of such a structure is a temporary steel grandstand erected using scaffolding system. Dynamic load that is generated by crowd movement has a significant influence on the behaviour of the structure and may lead to excessive structural vibrations. The aim of the study is to consider the idea of using polymer...
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Application of Barkhausen method to determine internal stresses in cold-rolled and hot-rolled sheets
PublikacjaThe paper presents investigations on internal stress distribution in plane hot—or cold-rolled sheets dedicated for the cold-formed profiles. The motivation of the research is a new profile design whose bending technology, incorporating a longitudinal welded joint and hot-dip galvanization after bending and welding introduces additional internal stresses. In order to identify the entirety of stresses in the process of sheet production...
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On the problem of optimised allocation of water quality sensors and actuators in DWDS
PublikacjaThe problems of water quality sensors and actuators placement in drinking water distribution systems (DWDSs) are addressed as separate, primarily. However, against the background of control systems theory, the nature of DWDSs dynamics indicates that these both problems are interdependent and impact the design of related water quality monitoring and control structures and algorithms. The research work presented in this paper is...
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On the correlation between magnetoacoustic emission and magnetostriction dependence on the applied magnetic field
PublikacjaThe correlation between magnetoacoustic emission signal envelopes and magnetostriction curves is investigated. Two sets of samples are being considered: tempered martensitic steel and plastically deformed ferritic steel. It is shown that even though some general relations may be observed, as was demonstrated in the literature, the correlation is not always present. One may not expect to change both quantities in the same way if...
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Corrosion monitoring by harmonic analysis in aqueous environments
PublikacjaThis paper presents tests concerning the rate of corrosion in non-alloy steel (type S235JR) in an aqueous environment, with an additive of sodium chloride by means of polarization resistance measurements and harmonic analysis. The tests have been carried out for steel samples exposed to the testing environment for six weeks, in order to obtain a constant rate of corrosion in the function of time. The measurements have aimed at...
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INFLUENCE OF SOLID PARTICLE CONTAMINATION ON THE WEAR PROCESS IN WATER LUBRICATED MARINE STRUT BEARINGS WITH NBR AND PTFE BUSHES
PublikacjaThis paper reports on a study of the influence of solid particle contamination on the wear process in water-lubricated slide bearings (steel-acrylonitrile-butadiene rubber (NBR) and steel- polytetrafluoroethylene (PTFE)). To compare the wear of the shaft journal and bushes (NBR and PTFE) when lubricated with fresh water and contaminated water, an experiment was carried out to identify key factors that influence the state of wear...
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Tribological Properties of Thermoplastic Materials Formed by 3D Printing by FDM Process
PublikacjaThe dataset entitled 3D printed ABS thermoplastic vs. steel. Dry sliding wear test in constant load & velocity ring on flat configuration. Test parameters: print layer thickness and orientation. Test symbol: 019_h_4 contains: the time base (expressed in seconds and minutes), the friction torque for sliding friction, rotational velocity of the counter – specimen (velocity of sliding), friction coefficient, load in the friction contact...
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Influence of ESPAR Antenna Radiation Patterns Shape on PPCC-Based DoA Estimation Accuracy
PublikacjaIn the article, we show the influence of three different electronically steerable parasitic array radiator (ESPAR) antenna radiation patterns on the overall direction of arrival (DoA) estimation accuracy when power-pattern cross-correlation (PPCC) algorithm, relying on received signal strength (RSS) values, is used for the estimation. The ESPAR antenna designs were obtained for three optimization...
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Validation of a virtual test environment for C2X communication under radio jamming conditions
PublikacjaIn this paper, we propose a novel car-2-x communication security testing methodology in the physical layer of wireless systems. The approach is dedicated to automated testing of autonomous vehicles and it is essential for such complex systems operation, especially with regard to safety and security issues. It is based on scenario-driven testing in virtual and real test environments created from collected or simulated data. The...
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pH-dependent composite coatings for controlled drug delivery system - Review
PublikacjaNowadays in case of long-term implants, the most common postoperative complications are bacterial infections, which in consequence may provoke loos- ening of the implants in the primary phase of stabilization. Bacterial infections are currently the most frequent cause of revision surgery of the implants such as hip joint endoprosthesis, knee joint endoprosthesis and dental implants. In order to provide the local and long-term antibacterial...
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Mechanical Performance and Environmental Assessment of Sustainable Concrete Reinforced with Recycled End-of-Life Tyre Fibres
PublikacjaThe presented research’s main objective was to develop the solution to the global problem of using steel waste obtained during rubber recovery during the tire recycling. A detailed comparative analysis of mechanical and physical features of the concrete composite with the addition of recycled steel fibres (RSF) in relation to the steel fibre concrete commonly used for industrial floors was conducted. A study was carried out using...
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Ocena pracy dźwigara zadaszenia Hali Blanika w Gdańsku
PublikacjaWartykule przedstawiono kompleksowe sprawdzenie nośności stalowej konstrukcji zadaszenia Hali Leszka Blanika w Gdańsku. Dokonano oceny wpływu otworów dużej średnicy w środnikach dźwigara na jego nośność. Oszacowano nośność nietypowego, zginanego styku doczołowego łączącego elementy dwuteowe klasy 4. Obliczenia wykonano na podstawie norm i analiz modeli MES.
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Corrosion behavior of concrete produced with diatomite and zeolite exposed to chlorides
PublikacjaChloride induced reinforcement corrosion is widely accepted to be the most frequent mechanism causing premature degradation of reinforced concrete structures. The electrochemical impedance of reinforcing steel in diatomite- and zeolite-containing concrete exposed to sodium chloride was assessed. Chemical, physical and mineralogical properties of three concrete samples (20% diatomite, 20% zeolite, and a reference containing neither)...
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Reliable method of assessing fracture properties of asymmetric bonded joints
PublikacjaTwo methods of assessing fracture properties of adhesive joints were studied. Two wedge tests: with continuous deflection and with force measurements were compared. Asymmetric geometry of the bonded joint was considered, i.e. two different plates of aluminium alloys: Al-Cu and Al-Mg, were bonded with epoxy DGEBA adhesive. The analytical model is shown to estimate the values of fracture properties: crack position and critical fracture...
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Antagonist adhesion effects due to variable substrate surface
PublikacjaThe effects of variability of intrinsic adhesion within a joint have been studied using a single cantilever beam (SCB) test. Fracture energy was found not to be a simple function of relative areas of 2 surface pre-treatments: a 'weak' zone decreased strength more than expected from simple, additive considerations. By severing the adhesive along the strong-weak transition, fracture energy increased.The prior antagonist effect appears...
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Surface Texture after Turning for Various Workpiece Rigidities
PublikacjaIn the paper, we present an analysis of the surface texture of turned parts with L/D (length/diameter) ratios of 6 and 12 and various rigidity values. The studies were carried out on samples made of S355JR steel and AISI 304 stainless steel. A detailed analysis of 2D surface profiles was carried out by using a large number of parameters that allowed us to distinguish significant differences in the surface microgeometry, which confirmed...
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Reference-free determination of debonding length in reinforced concrete beams using guided wave propagation
PublikacjaThis paper presents theoretical and experimental investigations of guided wave propagation in reinforced concrete beams, with pre-existing debonding between steel rebars and concrete blocks, for the purpose of damage detection. The primary aim of these investigations was a detailed analysis of the possible applications of wave propagation in single and multiple debonding detection in reinforced concrete structures and reference-free...
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Ship’s de-perming process using coils lying on seabed
PublikacjaA ship built from ferromagnetic steel disturbs the uniformity of the Earth’s magnetic field. Changes of ship’s signature are due to the magneto-mechanical interaction of the hull with the Earth’s magnetic field. The ship’s magnetic field can be detected by a magnetic naval mine. For this reason, the vessel has to be demagnetized. There are several methods of ship’s de-perming. The results of experimental and computer simulations...
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Effect of electrode waterproof coating on quality of underwater wet welded joints
PublikacjaIn this paper, the effects of different hydrophobic coatings on the surface of covered electrodes on the quality of wet welded carbon steel joints were discussed. Commonly available hydrophobic substances used in industrial applications were selected for the research. The aim of using waterproof coatings was to check the possibility to decreasing the susceptibility of highstrength low-alloy S460N steel to cold cracking. During...
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Numerical investigation of the core eccentricity effect on wave propagation in embedded waveguide
PublikacjaThe paper presents results of theoretical and numerical investigation of guided wave propagation in two-layer bars with geometric imperfections in the form of eccentric location of steel core. Steel rod of diameter equal to 1 cm embedded in composite mortar-type cover with external diameter equal to 5 cm has been taken into consideration. Several different rods with variable size of eccentricity are analysed. Results for rods with...
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TECHNOLOGIA RADIA PROGRAMOWALNEGO W ZASTOSOWANIACH WOJSKOWYCH
PublikacjaTechnologia radia programowalnego (Software Defined Radio) jest nowoczesnym rozwiązaniem umożliwiającym realizację urządzeń pracujących w różnego rodzaju systemach łączności radiowej, zarówno cywilnych, jak i wojskowych. W artykule zaprezentowano zagadnienia dotyczące koncepcji realizacji radia programowalnego. Opisano w sposób funkcjonalny platformę sprzętową i programową takiego rozwiązania. Zaprezentowano budowę przykładowej...
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ADAPTIVE IDENTIFICATION OF TIME-VARYING IMPULSE RESPONSE OF UNDERWATER ACOUSTIC COMMUNICATION CHANNEL
PublikacjaThe transmission properties of underwater acoustic communication channel can change dynamically due to the movement of acoustic system transmitter and receiver or underwater objects reflecting transmitted signal. The time-varying impulse response measurement and estimation are necessary to match the physical layer of data transmission to instantaneous channel propagation conditions. Using the correlative measurement method, impulse...
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PUBLIC SPACES FOR LOCAL LIFE / Shared values in diversified urban communities as a foundation for participatory provision of local public spaces, 23-27 May 2017, Ljubljana Slovenia
PublikacjaThe Urban Planning Institute of the Republic of Slovenia (UIRS) and partners hosted a 5-day international event addressing participatory planning of local urban public space in socially, economically and ethnically diverse communities. The event was structured in three interrelated activities: a seminar, a workshop and a field-trip. Special emphasis was given to the means of revealing shared values that local inhabitants and other...
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Investigations of Titanium Implants Covered with Hydroxyapatite Layer
PublikacjaTo reduce unfavorable phenomena occurring after introducing an implant into human body various modifications of the surface are suggested. Such modifications may have significant impact on biocompatibility of metallic materials. The titanium and it's alloys are commonly used for joint and dental implants due to their high endurance, low plasticity modulus, good corrosion resistance as well as biocompatibility. Special attention...
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Building damage due to structural pounding during earthquakes
PublikacjaEarthquake-induced pounding between adjacent buildings has been identified as one of the reasons for substantial damage or even total collapse of colliding structures. A major reason leading to interactions in buildings results from the differences in their dynamic parameters and also from insufficient distance between the structures. Although the research on structural pounding has been much advanced, the studies have mainly been...
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Repeated Projectile Impact Tests on Multi-Layered FibrousCementitious Composites
PublikacjaThis research aims to experimentally evaluate the behaviour of multi-layered fibrous cementitious composites withintermediate Glass Fibre Meshes (GFM) under repeated projectile load. The impact load was subjected through a convexedge projectile needle at a low velocity on cylindrical specimens of three-layered fibrous cementitious composites, whichhave two different steel fibre distributions. In series A mixtures, a constant steel...