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Search results for: ORTHOTROPIC COSSERAT COSSERAT LAMINATES CHARACTERISTIC LENGTH DRILLING ROTATION DOF IRREGULAR SHELLS
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Distortional buckling of composite thin-walled columns of a box-type cross section with diaphragms
PublicationDistortional buckling of axially compressed columns of box-like composite cross sections with andwithout internal diaphragms is investigated in the framework of one-dimensional theory. The channel membersare composed of unidirectional fibre-reinforced laminate. Two approaches to the member orthotropic materialare applied: homogenization based on the theory of mixture and periodicity cells, and homogenization basedon the Voigt–Reuss...
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Measurements of the mechanical system properties of "SpeedLine magnetic" ultra-fast robot prototype for IML labeling
Open Research DataThe mechanical system tests of the high-speed IML labeling robot "SpeedLine Magnetic" were carried out in order to analyze the effects of the drive system's operating parameters on vibration and noise.
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On degradation of glass/polyester laminate immersed in water
PublicationMechanical behaviour was compared for glass/ polyester laminates manufactured in the boatbuilding plant using three methods: hand lay-up, vacuum bagging, infusion. Specimens were tested in dry condition and following accelerated water immersion test (70°C- corresponding to the exposure of 30 years at 19°C). In three point bending test 40-50% reduction in laminate strength was observed due to water immersion. The highest degradation...
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The analysis of soil resistance during screw displacement pile installation
PublicationThe analysis of soil resistances during screw displacement pile installation based on model and field tests. The investigations were carried out as a part of research project, financed by the Polish Ministry of Science and Higher Education. A proposal of empirical method for prediction of rotation resistance (torque) during screw auger penetration in non-cohesive subsoil based on CPT result.
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A New Quaternion Encryption Scheme for Image Transmission
PublicationQuaternions are hypercomplex number of rank 4. They are often applied to mechanics in three-dimensional space and considered as one of the best ways to represent rotations. In this paper a new encryption scheme, based on the rotation of data vector in three-dimensional space around another quaternion (key) is proposed. A computer-based simulation was created to analyze the potential of the proposed encryption technique.
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Fuel, Oils and Greases, W, E, sem.01, zimowy 22/23
e-Learning CoursesDivision and origin of fuels. Fossil energy resources in Poland and in the world. Production and structure of fuel consumption. Main directions of crude oil processing. Classification and physical properties of gaseous and liquid fuels - natural gas, gasoline, kerosene, diesel oil, heating oil. Classification and characteristic indicators of solid fuels - hard coal, lignite, peat. Fuel contaminants and methods of their removal....
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The propagation of the waves in the CTO S.A. towing tank
PublicationThe paper presents the results of research focused on the wave propagation in the CTO S.A. deepwater towing tank. In the scope of paper, the wavemaker transfer function was determined for regular waves, based on the Biésel Transfer Function and further for irregular waves, based on Hasselman model of nonlinear energy transfer. The phenomena: wave damping, wave breakdown and wave reflection, were measured, analyzed and mathematically...
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NUMERICAL MODELLING AND EXPERIMENTATION OF HISTORICAL CARPENTRY CORNER LOG JOINTS
PublicationThe main purpose of this research is to determine the stress distributions on the contact surfaces between the logs of the historical carpentry corner joints. The additional purpose is to compare the stress distribution for four different boundary conditions in the case of dry and wet pine wood. The paper presents the results of numerical analysis of the shortcorner dovetail connection and the saddle notch corner joint, which are...
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Limits of enhanced of macro- and meso-scale continuum models for studying size effect in concrete under tension
PublicationThe paper investigates a mechanical quasi-static size effect in concrete during splitting tension at the macro- and meso-level. In experiments, five different diameters of cylindrical concrete specimens were tested. Twodimensional plane strain finite element (FE) simulations were carried out to reproduce the experimental size effect. The size effect in experiments by Carmona et al. was also simulated. Two enhanced continuum concrete...
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Fuel, Oils and Greases, W, E, sem.03, zimowy 22/23
e-Learning CoursesDivision and origin of fuels. Fossil energy resources in Poland and in the world. Production and structure of fuel consumption. Main directions of crude oil processing. Classification and physical properties of gaseous and liquid fuels - natural gas, gasoline, kerosene, diesel oil, heating oil. Classification and characteristic indicators of solid fuels - hard coal, lignite, peat. Fuel contaminants and methods of their removal....
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Wpływ parametrów strugi paliwa wtryskiwanego do cylindra silnika okrętowego na początkową fazę rozpylania
PublicationPrzedmiotem rozprawy jest analiza procesu wtrysku oleju napędowego do cylindra silnika okrętowego z zapłonem samoczynnym i bezpośrednim wtryskiem paliwa. Analiza tego zagadnienia została przeprowadzona w aspekcie wpływu makro parametrów strugi na początkową fazę rozpylania oleju napędowego. Celem niniejszej pracy jest określenie wpływu współczynnika L/D (długość otworu/średnica) otworu wylotowego wtryskiwacza na zmianę charakterystyki...
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A Novel Approach to Fully Nonlinear Mathematical Modeling of Tectonic Plates
PublicationThe motion of the Earth's layers due to internal pressures is simulated in this research with an efficient mathematical model. The Earth, which revolves around its axis of rotation and is under internal pressure, will change the shape and displacement of the internal layers and tectonic plates. Applied mathematical models are based on a new approach to shell theory involving both two and three-dimensional approaches. It is the...
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Flow of liquid in flat gaps of the satellite motor working mechanism
PublicationThe article describes the methodology and results of investigations of the flow of oil and HFA-E emulsion in flat gaps of the working mechanism of a satellite motor. The flow of liquid in those gaps is turbulent and not fully developed. The article presents two methods of modelling this flow. Method I makes use of the Darcy-Weisbach formula, while Method II bases on the assumption that in the variable-length gaps the flow is turbulent...
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Bending analysis of functionally graded nanoplates based on a higher-order shear deformation theory using dynamic relaxation method
PublicationIn this paper, bending analysis of rectangular functionally graded (FG) nanoplates under a uniform transverse load has been considered based on the modified couple stress theory. Using Hamilton’s principle, governing equations are derived based on a higher-order shear deformation theory (HSDT). The set of coupled equations are solved using the dynamic relaxation (DR) method combined with finite difference (FD) discretization technique...
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Free-surface elevation in open vortex flow controls
PublicationRotational form of fluid motion is complex, but very important in science and technology. The paper is devoted to the hydraulic mechanism of flow in open vortex flow controls, or regulators. The velocity field was described by the kinematic model, and intensity of rotation - by means of the energy balance between the input and dissipation. In consequence some algebraic expresions were obtained, which can be useful in approximated...
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Design aspects of a low-cost prosthetic arm for people with severe movement disabilities
PublicationIn this paper the main aspects of mechanical design behind the low-cost prosthetic arm are presented. The fundamentals of a proper design has been defined to obtain functional 3D printed 5 degree of freedom (DOF) prosthesis. The designed prosthetic arm is a part of the hybrid interface with eye tracking movement control. The main focus was to create affordable but usable prosthesis which corresponds in size and weights to the human...
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Electrical responses of Graphene-Silicon Schottky diodes toward nitrogen dioxide and tetrahydrofuran under irradiation
Open Research DataGraphene-Silicon Schottky junctions were utilized as gas sensors toward inorganic (nitrogen dioxide) and organic (tetrahydrofuran) gas qualitative and quantitative detection. The electrical responses of the sensors were collected in the form of current-voltage characteristics and measurements of current in time domain for a selected voltage bias. The...
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Head movement compensation algorithm in multi-display communication by gaze
PublicationAn influence of head movements on the gaze estimation accuracy when using a head mounted eye tracking system is discussed in the paper. This issue has been examined for a multi-display environment. It was found that head movement (rotation) to some extent does not influence on the gaze estimation accuracy seriously. Acceptable results were obtained when using eye-tracker to communicate with a computer via in two displays simultaneously.
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Receiver-side fingerprinting method for color images based on a series of quaternion rotations
PublicationThe proposed method is a new Joint Fingerprinting and Decryption (JFD) method that uses a cipher based on quaternion rotation to encrypt color images that are then sent to all users via multicast transmission. Individual encryption keys depend on the users’ fingerprints, so that a unique fingerprint is introduced into the image during decryption for each decryption key. A simulation-based research was conducted to examine the method’s...
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Oil refinery dusts: morphological and size analysis by TEM
PublicationThe objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as asupport for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs...
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Accurate and continuous adhesive fracture energy determination using an instrumented wedge test
PublicationThe wedge test and the related double cantilever beam test are practical methods of assessing structural adhesive fracture energy. In the former, and to a lesser extent the latter, a recognised problem is the difficulty of following the length of the growing crack, required to calculate fracture energy with any accuracy. We present a novel method of measurement of crack length that has the advantages of being accurate and allowing...
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Optimum shape of turnout diverging track with segments of variable curvature
PublicationIn the paper an attempt has been made to focus on shaping the variable curvature in the diverging track of the railway turnout. Basing on some earlier studies, solutions provided with a circular arc in the mid-zone, and in the extreme regions with segments of non-linear curvature of equal length and zero curvature at the start and end of the turnout, have been assumed as models. The most advantageous type of curvature has been...
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QRS Morphology-Based EDR Signal—Factors Determining its Properties
PublicationRespiration-induced signals contain a clinically significant information. It could be obtained utilizing both direct and indirect methods. ECG-Derived Respiration (EDR) method is the latter one. However, in this case, two approaches could be distinguished. First one is based on determining changes in the morphology of QRS complexes while the second one is based on the Respiratory Sinus Arrhythmia (RSA) mechanism. The former approach...
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Fatigue and Professional Burnout in Police Officers and Firefighters
PublicationExcessive demands, work overload and the working time arrangements are an important cause of burnout and fatigue in employees. Specific working time arrangements are characteristic of the internal security services, such as police officers and firefighters. This applies to both the ordering of day and night shifts and the length of shifts. Depletion of personal resources is a common component for acute fatigue and burnout. However,...
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SIMPLIFIED DYNAMIC MODEL OF ROTATING BEAM
PublicationIn the paper a hybrid model of rotating beam is presented. It was obtained by using two methods: modal decomposition and spatial discretization. Reduced modal model was built for the system without the load related to inertia forces that occur during beam rotation. This inertia load was next modeled by using the method of simply spatial discretization and combined with reduced modal model. This approach allows to obtain accurate...
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Curlicues generated by circle homeomorphisms
PublicationWe investigate the curves in the complex plane which are generated by sequences of real numbers being the lifts of the points on the orbit of an orientation preserving circle homeomorphism. Geometrical properties of these curves such as boundedness, superficiality, local discrete radius of curvature are linked with dynamical properties of the circle homeomorphism which generates them: rotation number and its continued fraction...
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Signature Partitioning Using Selected Population-Based Algorithms
PublicationDynamic signature is a biometric attribute which is commonly used for identity verification. Artificial intelligence methods, especially population-based algorithms (PBAs), can be very useful in the dynamic signature verification process. They are able to, among others, support selection of the most characteristic descriptors of the signature or perform signature partitioning. In this paper, we focus on creating the most characteristic...
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Buckling Analysis of a Micro Composite Plate with Nano Coating Based on the Modified Couple Stress Theory
PublicationThe present study investigates the buckling of a thick sandwich plate under the biaxial non-uniform compression using the modified couple stress theory with various boundary conditions. For this purpose, the top and bottom faces are orthotropic graphene sheets and for the central core the isotropic soft materials are investigated. The simplified first order shear deformation theory (S-FSDT) is employed and the governing differential...
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Buckling of simplified models of silo with corrugated walls and vertical stiffeners
PublicationThe paper deals with buckling of cylindrical silos composed of corrugated sheets and vertical stiffeners (columns). Comprehensive finite element analyses were carried out for a perfect silo by means of a linear buckling approach. Corrugated walls were simulated as an equivalent orthotropic shell and vertical thin-walled columns as beam elements. Calculations for perfect silos with different numbers of columns made it possible to...
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Brief Announcement: Energy Constrained Depth First Search
PublicationDepth first search is a natural algorithmic technique for constructing a closed route that visits all vertices of a graph. The length of such route equals, in an edge-weighted tree, twice the total weight of all edges of the tree and this is asymptotically optimal over all exploration strategies. This paper considers a variant of such search strategies where the length of each route is bounded by a positive integer B (e.g. due...
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Receiver-side fingerprinting method based on quaternion sandwich product
PublicationIn 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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Exercise bike powered electric generator for fitness club appliances
PublicationA generator powered by a stationary bicycle for the purposes of generating electricity for fitness club appliances is considered. A generator is connected to a stationary bicycle in such a way as the circular rotation of the front wheel rotates the coils of wires inside the generator between the poles of the magnets inside the generator. The resulting Direct Current is channeled to the attached battery bank and converted into different...
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INFLUENCE OF INLET GEOMETRY ON THE EFFICIENCY OF 1MW STEAM TURBINE
PublicationThe process of the design of the 1MW steam turbine includes designing the stator and rotor blades, the steam turbine inlet and exit, the casing and the rotor. A turbine that operates at rotation speeds other than 3000 rpm requires a gear box and generator with complex electronic software. This paper analyses the efficiency of eight turbine variants, including seven inlet geometries and three stages of stator as well as an eight...
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Mode shapes of a beam and plate with defects, obtained by experimental modal analysis
Open Research DataThe DataSet contains the experimental results of the first mode shape for a beam and a plate.
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Analiza doświadczalna wpływu długości zakotwienia pręta na zachowanie przyczepności w teście pull-out
PublicationArtykuł prezentuje badania przyczepności przeprowadzone przy użyciu testu pull-out. Eksperymenty miały na celu ocenę wpływu długości zakotwienia na przyczepność w tym teście. Z przeprowadzonej analizy wynika, że długość styku pręt-beton znacząco wpływa na zachowanie przyczepności. Określa ona typ zniszczenia połączenia, wpływa na rozkład i wartość naprężeń w pręcie oraz rzutuje na przebieg krzywej przyczepność-poślizg, która jest...
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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: 009_v_2
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 009_v_3
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 009_h_3
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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_v_5
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 009_h_5
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 009_h_4
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 039_h_4
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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_v_4
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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_5
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 039_v_4
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 009_v_4
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 039_v_3
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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_v_3
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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_3
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.
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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: 039_h_5
Open Research DataData gathered in sliding ring-on-block (flat contact) tribological experiment. Materials: alloy steel (heat treated) vs. ABS plastic.