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Wyniki wyszukiwania dla: mechanics
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Marcin Adam Zmuda Trzebiatowski dr inż.
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Comparison of the fracture toughness of pine wood determined on the basis of orthogonal linear cutting and frame sawing
PublikacjaIn this paper, the values of the fracture toughness of Scots pine determined by cutting tests are presented. The cutting tests were carried out using the samples of Scotch pine (Pinus sylvestris L.) from Pomeranian Region, Poland. These experiments were carried out on two research stands: orthogonal linear cutting tests were conducted using the microtome instrument and the frame saw PRW-15M was used for sawing tests. The values...
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HEAVE MOTION OF A VERTICAL CYLINDER WITH HEAVE PLATES
PublikacjaThe shape of a vertical cylinder resembles the classic form of a spar platform. Spar platforms are floating platforms that are successfully used in waters of great depths and have several advantages that mean they are readily used in the oil industry. Many of these advantages are also relevant to their application for offshore wind turbines, which is currently being considered. In the hydrodynamic analysis of spar platforms, the...
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Strongly anisotropic surface elasticity and antiplane surface waves
PublikacjaWithin the new model of surface elasticity, the propagation of anti-plane surface waves is discussed. For the proposed model, the surface strain energy depends on surface stretching and on changing of curvature along a preferred direction. From the continuum mechanics point of view, the model describes finite deformations of an elastic solid with an elastic membrane attached on its boundary reinforced by a family of aligned elastic...
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Rotor Blade Geometry Optimisation in Kaplan Turbine
PublikacjaThe paper presents the description of method and results of rotor blade shape optimisation. The rotor blading constitutes a part ofturbine flow path. Optimisation consists in selection of the shape that minimises ratio of polytrophic loss. Shape of the blade isdefined by the mean camber line and thickness of the airfoil. Thickness is distributed around the camber line based on the ratio ofdistribution. Global optimisation was done...
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Comparative testing of numerical models of river ice jams
PublikacjaIce processes in general, and ice jams in particular, play a dominant role in the hydrologic regime of Canadian rivers, often causing extreme floods and affecting the life cycle of many aquatic, terrestrial, and avian species. Various numerical models have been developed to help simulate the formation and consequences of these very dynamic and often destructive jam events. To test and compare the performance of existing models,...
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Generic appearance of objective results in quantum measurements
PublikacjaMeasurement is of central interest in quantum mechanics as it provides the link between the quantum world and the world of everyday experience. One of the features of everyday experience is its robust, objective character, contrasting the delicate nature of quantum systems. Here we analyze in a completely model-independent way the celebrated von Neumann measurement process, using recent techniques of information flow, studied in...
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TOPOLOGICAL CLUES FOR PREDICTING OUTCOMES OF MULTIPLAYER ONLINE BATTLE ARENA GAMES
PublikacjaWith 27 million people playing League of Legends every day, e-sports became more and more important part of our everyday life. Rise of its popularity builds a demand for better understanding e-sports mechanics on a deeper level. In the article, we test a hypothesis that it is possible to predict an outcome of Multiplayer Online Battle Arena game based on topological clues only (such as area of polygon where vertices are players...
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Digital Fingerprinting Based on Quaternion Encryption Scheme for Gray-Tone Images
PublikacjaIn this paper a new idea of digital images fingerprinting is proposed. The method is based on quaternion encryption in the Cipher Block Chaining (CBC) mode. Quaternion sare hyper-complex numbers of rank 4 and thus often applied to mechanics in three-dimensional space. The encryption algorithm described in the paper is designed for gray-tone images but can easily be adopted for color ones. For the encryption purpose, the algorithm...
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Mohammad Hossein Ghaemi dr inż.
OsobyMohammad Hossein Ghaemi (ur. 1967), adiunkt Wydziału Oceanotechniki i Okrętownictwa (WOiO) PG w Katedrze Automatyki i Energetyki. Jest absolwentem Uniwersytetu Teherańskiego z zakresu mechaniki ciała stałego, a także PG na kierunku Oceanotechnika. Uzyskał stopień doktora nauk technicznych na PG w 2004 roku. Od 1995 roku pracuje na WIMiO PG (do 2020 r. WOiO PG) i prowadzi zajęcia dydaktyczne i badania naukowe w zakresie automatyki...
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A concept for reducing PM 10 emissions for car brakes by 50%
PublikacjaWith regard to airborne particles with an aerodynamic diameter of less than 10 μm (PM10), in countries in the European Union, the mass of brake emissions equals approximately 8–27% of the total traffic-related emissions. Using a research methodology combining tests at different scale levels with contact mechanics simulations and PM10 chemical characterization, the REBRAKE EU-financed project had the following aims: i) to demonstrate...
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FURTHER REMARKS ON THE SURFACE VIS IMPRESSA CAUSED BY A FLUID-SOLID CONTACT
PublikacjaIt is well-known that, nano-mechanics should take into account not only physical phenomena occuring within the bulk but, first of all, the physical phenomena appropriate for a surface of two materials contact. The huge volume density of internal surfaces as well countours lines located within the nanomaterial results in our interest in, apart from classical form of mass, momentum and entropy transport, those modes of transportation...
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Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator
PublikacjaThis paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation – stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response...
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Evaluating experimental molecular physics studies of radiation damage in DNA*
PublikacjaThe field of Atomic and Molecular Physics (AMP) is a mature field exploring the spectroscopy, excitation, ionisation of atoms and molecules in all three phases. Understanding of the spectroscopy and collisional dynamics of AMP has been fundamental to the development and application of quantum mechanics and is applied across a broad range of disparate disciplines including atmospheric sciences, astrochemistry, combustion and environmental...
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Quantum Steering Inequality with Tolerance for Measurement-Setting Errors: Experimentally Feasible Signature of Unbounded Violation
Publikacjauantum steering is a relatively simple test for proving that the values of quantum-mechanical measurement outcomes come into being only in the act of measurement. By exploiting quantum correlations, Alice can influence — steer — Bob ’ s physical system in a way that is impossible in classical mechanics, as shown by the violation of steering inequalities. Demonstrating this and similar quantum effects for systems of increasing size,...
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Wavepacket of the Universe and its Spreading
PublikacjaWavepackets in quantum mechanics spread and the Universe in cosmology expands. We discuss a formalism where the two effects can be unified. The basic assumption is that the Universe is determined by a unitarily evolving wavepacket defined on space-time. Space-time is static but the Universe is dynamic. Spreading analogous to expansion known from observational cosmology is obtained if one regards time evolution as a dynamical process...
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Steering is an essential feature of non-locality in quantum theory
PublikacjaA physical theory is called non-local when observers can produce instantaneous effects over distant systems. Non-local theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in a well-known class of non-local games known as XOR games. In particular, optimal quantum strategies for XOR games are completely determined...
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Local hidden–variable models for entangled quantum states
PublikacjaWhile entanglement and violation of Bell inequalities were initially thought to be equivalent quantum phenomena, we now have different examples of entangled states whose correlations can be described by local hidden-variable models and, therefore, do not violate any of the Bell inequalities. We provide an up-to-date overview of the existing literature regarding local hidden-variable models for entangled quantum states, in both...
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Temperature-dependent structure-property modeling of viscosity for ionic liquids
PublikacjaIn this paper we present the methodology for assessing the ionic liquids' viscosity at six temperature points (25, 35, 45, 50, 60 and 70 [C]), which utilizes only the in silico approach. The main idea of such assessment is based on the "correction equation" describing the correlation between experimentally measured viscosity and theoretically derived density (calculated with use of molecular mechanics), given at 6 different temperature...
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Models of Structures in Didactics
PublikacjaThe final aim of teaching students subjects, such as structural mechanics, reinforced concrete, and steel structures is to teach them how structures work in a given building as well as to provide them with skills enabling them to calculate and design structures. The behavioral model of the structure, contrary to the architectural model, which focuses mainly on the external form of the building, shows workings from both the static...
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Structure of the Resource Theory of Quantum Coherence
PublikacjaQuantum coherence is an essential feature of quantum mechanics which is responsible for the departure between the classical and quantum world. The recently established resource theory of quantum coherence studies possible quantum technological applications of quantum coherence, and limitations that arise if one is lacking the ability to establish superpositions. An important open problem in this context is a simple characterization...
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Gravity-related research (2020/21)
Kursy OnlineThe goal of the subject is to extend of the knowledge gained in the framework of general mechanics (statics, kinematics, dynamics). Students will be familiarized with the description of the kinematics and dynamics of motion in typical gravity-related research conditions (microgravity in parabolic flights, drop towers, sounding rockets) as well as gravity-related research platforms, its opportunities and limitations. Additionally,...
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Gravity-related research (Engineering and Management of Space Systems) 21/22
Kursy OnlineThe goal of the subject is to extend of the knowledge gained in the framework of general mechanics (statics, kinematics, dynamics). Students will be familiarized with the description of the kinematics and dynamics of motion in typical gravity-related research conditions (microgravity in parabolic flights, drop towers, sounding rockets) as well as gravity-related research platforms, its opportunities and limitations. Additionally,...
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Natalia Krystyna Gietka dr inż.
OsobyOd 2014 roku pracownik Wydziału Inżynierii Lądowej i Środowiska Politechniki Gdańskiej. Obecnie adiunkt w Katedrze Geotechniki i Inżynierii Wodnej, w której rozwija swoje zainteresowania naukowe związane z dziedziną hydrauliki, mechaniki płynów, meteorologii i hydrologii. Wraz z Centrum Nowoczesnej Edukacji dąży do wprowadzania innowacyjnych rozwiązań w nauczaniu np. poprzez prowadzenie zajęć w formie grywalizacji na kierunku Inżynieria...
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Magdalena Oziębło dr inż.
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Modelling of Abdominal Wall Under Uncertainty of Material Properties
PublikacjaThe paper concerns abdominal wall modelling. The accurate prediction and simulation of abdominal wall mechanics are important in the context of optimization of ventral hernia repair. The shell Finite Element model is considered, as the one which can be used in patient-specific approach due to relatively easy geometry generation. However, there are uncertainties in this issue, e.g. related to mechanical properties since the properties...
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On Accuracy Modeling of Gas Turbine Cycles by the In-house COM-GAS Code
PublikacjaIn this paper, a comparison of accuracy modeling of gas turbine cycles between the basic (classical) model and the in-house COM-GAS code has been presented. The basic model uses a semi-perfect gas and well known projecting assumption. On the other hand, the computational flow mechanics (CFM) basis on a real gas by using thermodynamic tables. The thermodynamic analysis of thermal cycles, simply gas cycle GT8C and gas turbine cycle...
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Drop-coating deposition surface-enhanced Raman spectroscopy on silver substrates for biofluid analysis
PublikacjaUtilization of surface-enhanced Raman spectroscopy as a measurement technique is of particular interest in biodetection due to its superb chemical specificity and high sensitivity. The use of SERS substrates further improve this method by massive enhancement of the molecule Raman spectrum, permitting very low levels of detection. Therefore it is important to seek for new ways to develop reliable substrates, which are quickly and...
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Sawing Processes as a Way of Determining Fracture Toughness and Shear Yield Stresses of Wood
PublikacjaA new computational model, based on fracture mechanics, was used to determine cutting forces. Unlike traditional computing methods, which depend on many coefficients reflecting the machining of solid wood, the new model uses two main parameters: fracture toughness and shear yield stresses. The aim of this study was to apply this new method to determine these parameters for the tooth cutting edge principal positions and longitudinal...
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A constitutive law for concrete with smooth transition from continuous into discontinuous cracks’ description
PublikacjaPaper presents a constitutive model for concrete that combines a continuous and discontinuous crack’s description to simulate the concrete under tensile dominated loads. In a continuum regime, two different constitutive laws were used. First, a plasticity model with the Rankine failure criterion and an associated flow rule was used. Second, a constitutive law based on isotropic damage mechanics was formulated. Both model alternatives...
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2022-2023 - Wytrzymałość materiałów II, PG_00040052
Kursy OnlineOpanowanie wiedzy i umiejętności rozwiązywania złożonych zagadnień wytrzymałości prętów, powłok oraz płyt, mechaniki pękania i wytrzymałości zmęczeniowej, drgań prętów, oraz wybranych zastosowań metody elementów skończonych. The aim of the lectures is to deliver to the students the knowledge and abilities to solve the complex problems concerning the bars, shells, 3D structures, mechanics of cracking and fatique strength, vibrations...
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Anna Pestka dr inż.
Osoby -
Marcin Abramski dr hab. inż.
Osobyod 1990 r. do 1996 r. - studia magisterskie na Politechnice Gdańskiej, na Wydziale Budownictwa Lądowego na specjalności Konstrukcje Budowlane i Inżynierskie 30.01.1996 r. - uzyskanie stopnia naukowego mgr inż. od 09.1995 r. do 12.1995 r. i od 02.1996 r. do 09.1998 r. - praca w charakterze inżyniera budowy w Usługowej Spółdzielni Remontowo-Budowlanej "Poziom" w Gdańsku od 15.09.1998 r. do 31.12.2006 r. - zatrudnienie na Politechnice...
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Fracture surface formation of notched 2017A-T4 aluminium alloy under bending fatigue
PublikacjaThe effect of cyclic loading on facture surface topology in notched components made by aluminium alloys is not completely clear. Fractogra-phy and fracture mechanics can help to understand this interdependency. This paper aims to study the distribution of the fracture surface roughness of notched 2017A-T4 aluminium alloy after bending fatigue using an optical focus-variation surface measurement technique by applying the fracture...
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A design framework and a digital toolset supporting the early-stage explorations of responsive kinetic building skin concepts
PublikacjaIn this paper we present the first phase of our research on the development of a framework for early-stage responsive kinetic building skin design. The aims of this study were: to formulate a methodological and instrumental basis for the construction of the framework, to conduct an initial pre-assessment of its features, and finally to provide the first example of how the framework could be applied in practice. Importantly, at...
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AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublikacjaThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
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THE THERMODYNAMIC ANALYSIS OF THE SZEWALSKI HIERARCHIC VAPOUR CYCLE COOPERATED WITH THE SYSTEM OF HEAT RECOVERY
PublikacjaIn this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperated with the system of heat recovery from exhaust gases are presented. According to that purpose, the CFM (Computation Flow Mechanics [1,3]) approach has correctly been used. The whole system consists of the first traditional steam cycle, the second organic Rankine cycle (ORC) and system of heat recovery with use of water with temperature 90...
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Tomasz Krolikowski dr hab. inż.
OsobyIn 1996, I have graduated from the Faculty of Marine Science of Szczecin University and obtained a master's degree - ocean engineering engineer " - Control and Ocean Engineering Measurements". In 1994 I was hired as an assistant trainee at the Institute of Computer Science Technical University of Szczecin, and after graduating in 1996, I was employed as academic and teaching at the Institute of Computer Science in the Department...
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Water Resources Management - Winter Semester 2021-2022
Kursy OnlineWater Resources Management as defined for purpose of this course includes both water use and water excess management. The fundamental water resources engineering processes are the hydrologic processes and the hydraulic processes. The common threads that relate to the explanation of these processes are the fundamentals of fluid mechanics. The hydrologic processes include rainfall, evaporation, infiltration, rainfall-runoff and routing,...
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[NF] Physics research methods. Part III
Kursy OnlineKurs realizowany wspólnie dla doktorantów szkoły doktorskiej i studiów doktoranckich The course is conducted jointly for PhD students of the doctoral school and doctoral studies Franco Bagnoli, University of Florence, Italy - "Thermodynamics, Statistical Mechanics, and Kinetic Gas Theory https://enauczanie.pg.edu.pl/moodle/course/view.php?id=5259 Course type: lecture Total hours of training (part III): 15 teaching hours
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[NF] Physics research methods. Part II.
Kursy OnlineKurs realizowany wspólnie dla doktorantów szkoły doktorskiej i studiów doktoranckich The course is conducted jointly for PhD students of the doctoral school and doctoral studies Franco Bagnoli, University of Florence, Italy - "Thermodynamics, Statistical Mechanics, and Kinetic Gas Theory with a computational perspective. https://enauczanie.pg.edu.pl/moodle/course/view.php?id=5259 Course type: lecture Total hours of training...
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Structured deformation of granular material in the state of active earth pressure
PublikacjaThe paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active...
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Experimental observations on the creep behaviour of frozen soil
PublikacjaConstitutive models in the literature for creep of frozen soil are based on the direct use of time counted from the onset of creep. An explicit time dependence in a constitutive equation violates the principles of rational mechanics. No change in stress or temperature is allowed for during creep, using the time-based formulations. Moreover, the existing descriptions need much verification and improvement on the experimental side...
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A coupled constitutive model for fracture in plain concrete based on continuum theory with non-local softening and eXtended Finite Element Method
PublikacjaThe paper presents a constitutive model for concrete which combines a continuous and discontinuous fracture description. In a continuum regime, two different constitutive laws were used. First, a plasticity model with a Rankine failure criterion and an associated fl ow rule was used. Second, a constitutive law based on isotropic damage mechanics was formulated. In order to capture the width of a localized zone and to obtain mesh-independent...
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Water Resources Management 2022/2023
Kursy OnlineWater Resources Management as defined for purpose of this course includes both water use and water excess management. The fundamental water resources engineering processes are the hydrologic processes and the hydraulic processes. The common threads that relate to the explanation of these processes are the fundamentals of fluid mechanics. The hydrologic processes include rainfall, evaporation, infiltration, rainfall-runoff and routing,...
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Wpływ wysokiej osteotomii piszczelowej na mechanikę stawu kolanowego
PublikacjaW rozprawie podjęto próbę weryfikacji wpływu zabiegu chirurgicznego wysokiej osteotomii piszczelowej na mechanikę stawu kolanowego. Po wykonanym przeglądzie literatury, postawiono trzy hipotezy, które poddano weryfikacji na drodze badań numerycznych. Otrzymane wyniki zwalidowano poprzez badania nacisków powierzchniowych występujących w stawach kolanowych świni domowej, prowadzonych na maszynie do jednoosiowego ściskania. Praca...
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On the deformation and frequency analyses of SARS-CoV-2 at nanoscale
PublikacjaThe SARS-CoV-2 virus, which has emerged as a Covid-19 pandemic, has had the most significant impact on people's health, economy, and lifestyle around the world today. In the present study, the SARS-CoV-2 virus is mechanically simulated to obtain its deformation and natural frequencies. The virus under analysis is modeled on a viscoelastic spherical structure. The theory of shell structures in mechanics is used to derive the governing...
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Analyses of Shear Angle in Orthogonal Cutting of Pine Wood
PublikacjaThe determination of energy effects for wood machining processes, such as cutting power and cutting forces, is very useful in designing of manufacture process of wooden products. A more accurate prediction of cutting forces requires a correct determination of the shear angle value, which can be determined using various models. In this article, shear angle values for an orthogonal linear cutting process of pine wood are determined. The...
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Revisiting the estimation of cutting power with different energetic methods while sawing soft and hard woods on the circular sawing machine: a Central European case
PublikacjaIn the classical approaches, used in Central Europe in practice, cutting forces and cutting power in sawing processes of timber are commonly computed by means of the specific cutting resistance kc. It needs to be highlighted that accessible sources in handbooks and the scientific literature do not provide any data about wood provenance, nor about cutting conditions, in which cutting resistance has been empirically determined. In...
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Surface sliding in human abdominal wall numerical models: Comparison of single-surface and multi-surface composites
PublikacjaDetermining mechanical properties of abdominal soft tissues requires a coupled experimental-numerical study, but first an appropriate numerical model needs to be built. Precise modeling of human abdominal wall mechanics is difficult because of its complicated multi-layer composition and large variation between specimens. There are several approaches concerning simplification of numerical models, but it is unclear how far one could...