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Search results for: DYNAMIC HIP SCREW
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The early failure of the gamma nail and the dynamic hip screw in femurs with a wide medullary canal. A biomechanical study of intertrochanteric fractures
PublicationBackground: Intertrochanteric fractures may occur in a bone with a wide medullary canal that may lead to significant mobility of a intramedullary nail, contrary to an extramedullary device. This study evaluates the Dynamic Hip Screw and the gamma nail in AO 31.A2.1 fractures in these circumstances. Methods: Synthetic femora with canals drilled to 18 mm were used. Five fixation types were examined: a 2 - hole and a 4 – hole Dynamic...
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A proposition of the computational model for the dynamic analysis of stress and strain distribution in the hip joint
PublicationCelem pracy jest sformułowanie zadania modelowania dynamiki odkształceń i rozkładu naprężeń stawu biodrowego, a w szczególności kości udowej, pod wpływem sił mięśniowych oraz zadanych sił zewnętrznych. Rozwiązanie tego zadania pozwoli wyjaśnić niektóre zjawiska np. jakie ruchy kości udowej oraz jakie materiały użyte do jej alloplastyki są przyczyną urazów i poważnych uszkodzeń. Omówiono problemy związane z zastosowaniem metody...
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Simulation of signal acquisition from a rotary flowmeter
Open Research DataThe dataset contains results of simulation measuring the flow of homogeneous substances by rotational flow meter: a moment of impulse at the output of flow meter, time between successive pulses, number of pulses counted from standard generator and relative error of measurement.
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Wpływ polietylenu szczepionego bezwodnikiem maleinowym oraz sił ścinających na właściwości mieszanin polietylen wysokiej gęstości-miał gumowy
PublicationScharakteryzowano wpływ kompatybilizatora w postaci polietylenu szczepionego bezwodnikiem maleinowym na właściwości mieszanin PE-HD–miał gumowy. Kompozycje termoplastyczne zawierające 50 cz. mas. rozdrobnionych odpadów gumowych, otrzymano przy użyciu współbieżnej wytłaczarki dwuślimakowej. Poziom sił ścinających generowanych podczas mieszania, regulowano za pomocą zmian prędkości obrotowych ślimaków. Przeprowadzono charakterystykę...
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The influence of screw configuration and screw speed of co-rotating twin screw extruder on the properties of products obtained by thermomechanical reclaiming of ground tire rubber
PublicationThe results of our investigations on the process of continuous thermomechanical reclaiming of ground tire rubber (GTR) carried out using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear forces. The influence of screw configuration and screw speed on breaking of chemical crosslink bonds contained in ground tire...
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DYNAMIC SYSTEMS AND APPLICATIONS
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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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Project of hip joint endoprothesis for an individual patient with materials selection
PublicationThis work includes the hip replacement design, based on the patient's medical records, the description of creation process and materials used for individual components.
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Hip endhoprothesis development using rapid prototyping methods
PublicationIntegrated product development based on Rapid Prototyping methods, connected with computer aided 3D design and computer aided engineering enables fast and full new product verification and validation. A case study derived from clinical and technological practice using hip implant construction is also included.
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Influence of the femoral offset on the muscles passive resistance in total hip arthroplasty
PublicationBackground Soft tissue tension is treated as a crucial factor influencing the post-THA dislocation. The femoral offset is regarded as one of the major parameters responsible for the stabilization of the prosthesis. It is unclear which soft tissue is mostly affected by the offset changes. Methods A finite element model of the hip was created. The model comprised muscles, bones, a stem, the acetabular component and a liner. The muscles...
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3D Computer Model of the Hip Joint Cartilage
PublicationThis paper presents 3D computer model of the hip joint cartilage in the ANSYS program. Model is made on the basis of anatomy and collected data on the material constants of bone and cartilage components. Analysis and comparison of biochemical model, viscoelastic and molecular mixed - aggregation serves to facilitate the creation of the next model of reality, which could be used in the design of joint prostheses. The correctness...
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Effect of lag screw on stability of first metatarsophalangeal joint arthrodesis with medial plate
PublicationBackground: First metatarsophalangeal joint (MTP-1) arthrodesis is a commonly performed procedure in the treatment of disorders of the great toe. Since the incidence of revision after MTP-1 joint arthrodesis is not insignificant, a medial approach with a medially positioned locking plate has been proposed as a new technique. The aim of the study was to investigate the effect of the application of a lag screw on the stability and...
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FEM modelling of screw displacement pile interaction with subsoil
PublicationPredicting the-settlement characteristics of piles is an important element in the designing of pile foundations. The most reliable method in evaluating pile-soil interaction is the static load test, preferably performed with instrumentation for measuring shaft and pile base resistances. This, however, is a mostly post-implementation test. In the design phase, prediction methods are needed, in which numerical simulations play an...
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Hip International
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Hip and Pelvis
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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Numerical simulation of screw displacement pile interaction with non-cohesive soil
PublicationA trial numerical simulation of screw displacement pile interaction with non-cohesive subsoil during the transfer of compression load. The simulation was carried out in an axisymmetric system. The technological phases of pile installation in the ground were numerically modelled using equivalent processes which provided similar effects to real technical actions. The results of the numerical calculations were verified by comparing...
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Multi-screw extruders – an overview
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Results of the “DPDT-Auger” Research Project on Screw Displacement Piles
PublicationThe main objective of the “DPDT-Auger” research project was to test the prototype DPDT auger for forming screw displacement piles in the ground (patented in Poland in 2020). An additional aim was to develop design methods and rules for the making of such piles. The augers and piles were first tested on a model scale, and then more extensively in the real scale on experimental field plots. The results found the overall functionality...
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THE DETERMINATION OF ABRASION RESISTANCE OF SELECTED BIOMATERIALS FOR THE FRICTION PAIRS IN THE HIP JOINT ENDOPROSTHESIS
PublicationThe key requirement for the modern endoprosthesis is high durability of the friction components, which results in long and trouble-free operation in the human body. The durability of currently used endoprosthesis is often limited by tribological wear processes of friction components (e.g. between the head and the acetabular component in a hip joint endoprosthesis) [8, 19, 23, 24]. In order to compare the tribological wear, tribological...
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Recycling of Waste Rubber by Thermo-Mechanical Treatment in a Twin-Screw Extruder
PublicationRecycling of waste tires is a significant issue considering both environmental and economic aspects. One of the leading recycling routes is the shredding of tires resulting in the generation of ground tire rubber. This material can be easily introduced into various polymer matrices as a filler, reducing the use of conventionally applied petroleum-based materials. In such cases, it is essential to ensure sufficient interfacial compatibility,...
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Identification of residual force in static load tests on instrumented screw displacement piles
PublicationOccurrence of the so-called residual force of an unknown value significantly disturbs interpretation of static load tests performed on piles equipped with additional measuring instruments. Screw displacement piles are the piling technology in which the residual force phenomenon is very common. Its formation mechanism is closely related to the installation method of this type of piles, which initiates generation of negative pile...
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The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
PublicationThe search for new ways to recycling of rubber waste has been the aim of many studies conducted by research centers and companiesworldwide. The results of our investigations on the process of continuous thermomechanical devulcanization of ground tire rubber using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear...
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Blade Section Prpfile Array Lifting Surface Design Method for Marine Screw Propeller Blade
PublicationThe lifting surface model is widely used in screw propeller design and analysis applications. It serves as a reliable tool for determination of the propeller blade mean line and pitch distribution. The main idea of this application was to determine the blade shape that would satisfy the kinematic boundary condition on its surface with the prescribed bound circulation distribution over it. In this paper a simplified lifting surface...
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Efficiency of thermomechanical reclaiming of ground tire rubber conducted in counter-rotating and co-rotating twin screw extruder
PublicationIn this article the results of research on a continuous thermomechanical reclaiming process of ground tire rubber (GTR) conducted in a twin screw extruder are presented. The effects of the rotation direction (co-rotating/counter-rotating), design of co-rotating plasticizing units and the rotational speed of the screws on the extruder working parameters, sol fraction and the degree of reclaiming in the obtained products were described....
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Advanced field investigations of screw piles and columns
PublicationPrzedstawiono opis badań pali i kolumn wkręcanych na terenowym poletku doświadczalnym, wykonanych w ramach projektu badawczego MNiSW. Badania statyczne pali i kolumn wykonano z zaawansowanym systemem do pomiaru rozkładu siły wzdłuż trzonów. Przedstawiono podstawowe wyniki badań z rozdziałem obciążenia na podstawę i pobocznicę pali i kolumn.
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Sustainable upcycling of brewers’ spent grain by thermo-mechanical treatment in twin-screw extruder
PublicationThermo-mechanical treatment of brewers’ spent grain (a by-product of beer manufacturing) was successfully performed via the extrusion process. The impact of temperature (from 30 to 180 °C), throughput (from 1 to 5 kg/h) and screw speed (from 75 to 375 rpm) on particle size, color, chemical structure, antioxidant activity and thermal stability of resulting material, as well as correlations between particular properties, were investigated....
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Human hip joint lubrication for permeable cartilage
PublicationPraca przedstawia pewien model obliczeń wartości sił tarcia zapisany w ortogonalnych sferycznych i innych krzywoliniowych układach współrzędnych dla hydrodynamicznego, niesymetrycznego przepływu cieczy synowialnej o własnościach nienewtonowskich i zmiennej lepkości w szczelinie stawu biodrowego człowieka z uwzględnieniem zmian losowych. Według informacji autora tak przedstawiony model nie był do tej pory rozpatrywany w pracach...
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Pressure and capacity in hip joint afte injury.
PublicationPraca przedstawia zarys analitycznego wyprowadzenia równania Reynoldsa do wyznaczania rozkładów wartości ciśnienia w szczelinie sferycznego stawu biodrowego człowieka po udarze w nieustalonym ruchu impulsywnym. W wyprowadzonym modelu uwzględniono lepkosprężyste właściwości cieczy synowialnej oraz stochastyczny opis chropowatości chrząstki stawowej. Numeryczne wartości ciśnienia wyznaczono w programie Mathcad 2001 przy wykorzystaniu...
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Dynamic Games and Applications
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Dynamic coloring of graphs
PublicationDynamics is an inherent feature of many real life systems so it is natural to define and investigate the properties of models that reflect their dynamic nature. Dynamic graph colorings can be naturally applied in system modeling, e.g. for scheduling threads of parallel programs, time sharing in wireless networks, session scheduling in high-speed LAN's, channel assignment in WDM optical networks as well as traffic scheduling. In...
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Journal of Hip Preservation Surgery
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Effect of Compounding Conditions on Static and Dynamic Mechanical Properties of High Density Polyethylene/Ground Tire Rubber Blends
PublicationSearching for new and cost-effective methods of waste rubber recycling is a subject of research in many scientific centers in the world. In this paper there are presented results of the research of the extrusion process of cheap and environmentally friendly thermoplastic compositions containing 50 % wt. of masses of ground tire rubber (GTR). The aim of this study was to determine the relationship between the mixing conditions and...
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Computed Tomography in Evaluation of Revision Hip Arthroplasty Outcomes
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Screw displacement pile shaft deformations measured by vibrating wire and fiber optic systems during a static load test
PublicationThis paper describes a full scale static load test performed on a 400 mm diameter screw displacement pile equipped with four different strain measuring systems. Three types of vibrating wire strain gauges (VWSG) were used: global - retrievable, local attached to steel pipe and local concrete embedded. The fourth system was distributed fiber optic sensors based on Rayleigh back scattering (DFOS) - three in the pile cross section....
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The Dynamic Model of Magnetic Hysteresis
PublicationThis paper presents the scalar dynamic magnetic hysteresis model based on the Preisach theory. The important role in this theory played hysteresis operator states. The changes of these operators` states are not immediate in the dynamic model but they are a function of time and parameter k representing the magnetic properties of the material. In this paper the transient state of the hysteresis operator is defined by the nonlinear...
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Friction forces for human hip joint at a naturally permeable cartilage
PublicationNiniejsza praca omawia różne rodzaje sił tarcia występujących w szczelinach stawów człowierka. W artykule dokonano analizy kilku ważnych czynników wpływających na wartości sił tarcia występujących w stawach człowieka. Rozważa się siły tarcia wywołane klasycznym hydrodynamicznym smarowaniem, wzmożonym hydrodynamicznym smarowaniem, wyciskaniem a także przesączaniem cieczy synowialnej do i z porowatej warstwy chrząstki stawowej.
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Dual-Energy Computed Tomography in Loosening of Revision Hip Prosthesis
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Periodic and impulsive lubrication of hip joint with stochastic rough surface.
PublicationNiniejsza praca przedstawia porównanie wartości nośności uzyskanych numerycznie dla niestacjonarnego smarowania impulsywnego oraz niestacjonarnego smarowania periodycznego sferycznego stawu biodrowego człowieka. W obu przypadkach przyjęto, że smarująca ciecz synowialna ma własności lepkosprężyste a występy chropowatych powierzchni chrząstki stawowej zmieniają się losowo. Charakterystyki zmiennych w czasie rozkładów wartości ciśnienia...
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Impulsive lubrication of hip joint for hypo-elastic cartilage model
PublicationPraca rozwiązuje problem smarowania stawu biodrowego człowieka w warunkach niestacjonarnych z uwzględnieniem hypo-sprężystych (pod-sprężystych) właściwości odkształcalnej szkieletu chrząstki stawowej. Prezentowane są rozkłady wartości ciśnienia hydrodynamicznego oraz zmienne w czasie rozkłady wartości sił nośnych.
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Dynamic charging of electric buses
PublicationDespite the continuous development of electrochemical battery technology and the multitude of electric buses on offer, it is still not possible to exploit electric buses in urban transport on an all-day basis without the necessity of charging them. It is therefore necessary to build point-to-point contact charging stations or induction charging stations at the terminals. This results in substantial financial outlays connected with...
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Solving the Problem of Dynamic Adaptability of Artificial Intelligence Systems that Control Dynamic Technical Objects
PublicationThis paper investigates the increase in the response speed and stability of artificial intelligence systems that control dynamic technical objects. The problem of calculating the optimal time of switching an artificial intelligence system between software classes by the criterion of the rigidity degree of the model of a control object is considered. The solution of this problem is proposed for the general case of the control object...
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Estimating and Forecasting GDP in Poland with Dynamic Factor Model
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Nanotubular Oxide Layer Formed on Helix Surfaces of Dental Screw Implants
PublicationSurface modification is used to extend the life of implants. To increase the corrosion resistance and improve the biocompatibility of metal implant materials, oxidation of the Ti-13Nb- 13Zr titanium alloy was used. The samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of...
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Footbridges. Dynamic Design – Selected Problems
PublicationModern footbridges create challenge in esthetic and structural design. Breaking the proven canons is a recipe for architectural success. However esthetic form has to be also a functional pedestrian bridge. Therefore a good FEM modeling is a key element in engineering part of design. The paper presents selected problems related to the modeling of the dynamic construction of footbridges. Several basic dynamic problems concerning...
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Journal of Dynamic Behavior of Materials
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Dynamic Relationships Management Journal
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Contribution of dynamic vehicle loads to pavement failure
PublicationPavement surfaces are not ideally even, which causes dynamic loads of vehicle axles. Distribution of dynamic loads of a given axle is similar to normal distribution and can be described by static load and dynamic load coefficient. The dynamic load coefficient depends on road profile, vehicle speed, properties of suspensions and static load of axle. While for a given road section road profile remains constant, vehicle speed and...
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Marek Szelągowski dr
PeopleMarek Szelągowski has participated in the creation and implementation of IT solutions in the fields of accounting, human resources management, production, IT infrastructure management, etc. As the CIO of the BUDIMEX Group in 2000–2008 he was responsible for the accommodation of informatization strategies to the changing needs of the business sector. He was managing and participating in analyses and optimizations of business processes...
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Dynamic Content Internationalization in Web Applications
PublicationThis paper shows a concept for providing dynamic internationalization to web applications. Presented work is based on the Java Web Platform but described concepts can be successfully implemented on other platforms. It shows how textual data being part of web pages static and dynamic content can be localized dynamically during application runtime. All concepts presented were or are still being developed in an existing conference...