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Development of an Advanced Control Algorithm for DAB DC/DC Converters: Inrush Current Limitation and Enhanced Operation in Transient States.
PublicationThe publication addresses the dynamic state challenges encountered during development of a dual active bridge (DAB) converter within DC microgrid systems. The conventional startup method is identified as instigating a cascade of unfavorable outcomes, encompassing elevated starting current, transformer current asymmetry, DC voltage distortions, EMI and heightened thermal stress on semiconductor components. Additionally, it necessitates...
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Wypalenie zawodowe: czy potrzebne jest leczenie?
PublicationProfessional burnout syndrome is an indicator of a process of health deterioration related to work. According to the Job Demands-Resources Theory, professional burnout develops in the workplace as a result of excessive job demands that are not balanced by personal and organizational resources. Professional burnout can affect employees across various sectors and organizations. The World Health Organization defines burnout as a syndrome...
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Mechanical characteristics of welded joints between different stainless steels grades
Publicationnvestigation of mechanical characteristics of welded joints is one of the most important tasks that allow determining their functional properties. Due to the very high, still rising, cost of some stainless steels it is justified, on economic grounds, welding austenitic stainless steel with steels that are corrosion-resistant like duplex ones. According to forecasts the price of...
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Modelling of high frequency dynamic responses of engineering structures
PublicationModelling of high frequency dynamic responses of engineering structures, especially those related to wave propagation, is a real numerical challenge. Nowadays most of numerical models, used for that purpose, are based on the application of various finite element techniques. However, finite element discrete models may also be considered as possessing certain periodic structures, which may manifest themselves in particular scenarios....
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Design of Structure of Tension Leg Platform for 6 MW Offshore Wind Turbine Based On Fem Analysis
PublicationThe article presents the calculation and design stages of the TLP platform serving as a supporting construction of a 6 MW offshore wind turbine. This platform is designed to anchor at sea at a depth of 60 m. The authors presented the method of parameterization and optimization of the hull geometry. For the two selected geometry variants, the load and motion calculations of the platform subjected to wind, wave and current under...
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Novel liquid chromatography method based on linear weighted regression for the fast determination of isoprostane isomers in plasma samples using sensitive tandem mass spectrometry detection
PublicationA simple, fast, sensitive and accurate methodology based on a LLE followed by liquid chromatography–tandem mass spectrometry for simultaneous determination of four regioisomers (8-iso prostaglandin F2α, 8-iso-15(R)-prostaglandin F2α, 11β-prostaglandin F2α, 15(R)-prostaglandin F2α) in routine analysis of human plasma samples was developed. Isoprostanes are stable products of arachidonic acid peroxidation and are regarded as the...
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Effect of osmolytes of different type on DNA behavior in aqueous solution. Experimental and theoretical studies
PublicationOsmolytes, the small organic molecules accumulated in cells under environmental stress, can modulate the stability of biopolymers such as proteins and DNA. In spite of many years of research, there is no established molecular mechanism of the influence of osmolytes on DNA structure. Here, we used two model osmolytes that denature (urea) or stabilize (trimethylglycine, TMG) proteins to study their effect on DNA in aqueous solutions...
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A Semiautomatic Experience-Based Tool for Solving Product Innovation Problem
PublicationIn this paper we present the idea of Smart Innovation Engineering (SIE) System and its implementation methodology. The SIE system is semi-automatic system that helps in carrying the process of product innovation. It collects the experiential knowledge from the formal decisional events. This experiential knowledge is collected from the group of similar products having some common functions and features. The SIE system behaves like...
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Tensile validation tests with failure criteria comparison for various GFRP laminates
PublicationThe paper studies the mechanical properties of glass fibre reinforced polymers (GFRP) with various types and orientation of reinforcement. Analyzed specimens manufactured in the infusion process are made of polymer vinyl ester resin reinforced with glass fibres. Several samples were examined containing different plies and various fibres orientation [0, 90] or [+45, –45]. To assess the mechanical parameters of laminates, a series...
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Nonlinear dynamic analysis of the pure “buckling” mechanism during blow-out trauma of the human orbit
PublicationConsidering the interplay between orbital bones and intraorbital soft tissues, commonly accepted patterns of the blow-out type of trauma within the human orbit require more thorough investigation to assess the minimal health-threatening impact value. Two different three-dimensional finite element method (FEM) models of the human orbital region were developed to simulate the pure “buckling” mechanism of orbital wall fracture in...
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Mechanical simulation of artificial gravity in torus-shaped and cylindrical spacecraft
PublicationLarge deformations and stress analyses in two types of space structures that are intended for people to live in space have been studied in this research. The structure under analysis is assumed to rotate around the central axis to create artificial gravitational acceleration equal to the gravity on the Earth's surface. The analysis is fully dynamic, which is formulated based on the energy method by using the first-order shear deformation...
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Nitric Oxide-Dependent Pathways as Critical Factors in the Consequences and Recovery after Brain Ischemic Hypoxia
PublicationBrain ischemia is one of the leading causes of disability and mortality worldwide. Nitric oxide (NO), a molecule that is involved in the regulation of proper blood flow, vasodilation, neuronal and glial activity constitutes the crucial factor that contributes to the development of pathological changes after stroke. One of the early consequences of a sudden interruption in the cerebral blood flow is the massive production of reactive...
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Effect of Tool Positioning Factors on the Strength of Dissimilar Friction Stir Welded Joints of AA7075-T6 and AA6061-T6
PublicationFriction 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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Telomere uncapping by common oxidative guanine lesions: Insights from atomistic models
PublicationOxidative damage to DNA is widely known to contribute to aging and disease. This relationship has been extensively studied for telomeres – structures that cap chromosome ends – due to their role in cell proliferation and senescence, and exceptional susceptibility to oxidation. Indeed, the repetitive telomeric DNA sequence contains the 5′-GGG-3′ motif that has the lowest ionization potential of all trinucleotides. Accordingly, experiments...
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Model of Nutrient and Pesticide Outflow with Surface Water to Puck Bay (Southern Baltic Sea)
PublicationCoastal basins are particularly exposed to the adverse impact of anthropogenic stress. In many places, despite only the seasonal increase in the number of residents, progressive urbanization and associated changes in the catchment characteristics are noticeable. Puck Bay is part of the Gulf of Gdansk and belongs to the Baltic Sea. Although the area of Puck Bay is covered by the Natura 2000 Network, this has not saved it from eutrophication...
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ANTIOXIDANT POWER SERIES (APS) AS A TOOL FOR RATIONAL DESIGN AND ASSESSMENT OF HEALTH PROMOTING PROPERTIES OF FUNCTONAL FOODS BASED ON ANTIOXIDANT PHYTOCHEMICALS
PublicationOver past decades, plantborne antioxidants dominated so called "translational research" in the area of food, nutrition, and disease prevention. Among consumers and producers, such phytochemicals are synonyms of nutriceuticals. Popularity and commercial success of antioxidants stems from mechanistic studies suggesting the involvement of reactive oxygen species in etiology of chronic diseases. However, epidemiology failed to provide...
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Smart Innovation Engineering Using Set of Experience and Decisional DNA
PublicationKnowledge-based Engineering Systems are founded upon integration of knowledge into computer systems and are one of the core requirements for the future Industry 4.0. Since the fourth industrial revolution is passing through the developing phase, implementation of Cyber-Physical Production Systems require more realistic approach. Knowledge Management and Knowledge Engineering plays an important role in manufacturing industries facing...
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The thermal effort during marine steam turbine flooding with water
PublicationThe work discussed an extreme case of cooling a steam turbine. The ship's steam turbine was used as an example. In marine transport units with low-speed engines dominate, however, there are also units with steam turbines. An example of analysed marine steam turbine is shown in Fig. 1. When considering the issue of cooling steam turbines, it is necessary to estimate the extreme conditions that may occur during operation of the turbine....
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Three dimensional simulations of FRC beams and panels with explicit definition of fibres-concrete interaction
PublicationHigh performance concrete (HPC) is a quite novel material which has been rapidly developed in the last few decades. It exhibits superior mechanical properties and durability comparing to normal concrete. HPC can achieve also superior tensile performance if strong fibres (steel or carbon) are implemented in the matrix. Thus, there exist the unabated interest in studying how the addition of different types of fibres modifies the...
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Influence of soil anisotropic stiffness on the deformation induced by an open pit excavation.
PublicationIn this paper, the problem of deformation induced by an open pit excavation in anisotropic stiff soils is analysed by FE modelling. The presented research is focused on the influence of material model with anisotropic stiffness on the accuracy of deformation predictions as compared with the field measurements. A new hyperelastic-plastic model is applied to simulate anisotropic mechanical behaviour of stiff soils. It is capable...
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Carbon Nanomaterials in Seed Priming: Current Possibilities
PublicationThe prevailing agricultural system has become deeply ingrained and insufficient due to outdated practices inherited from the Green Revolution, necessitating innovative approaches for sustainable agricultural development. Nanomaterials possess the potential to significantly improve the efficient utilization of resources while simultaneously encouraging sustainability. Among these, carbonaceous nanomaterials have found diverse applications...
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Application of Tensile Creep Test and Viscoelastic Method to the Analysis of Thermal Stresses at Low Temperatures
PublicationThe paper presents the viscoelastic method of thermal stresses calculation with utilization of results from tensile creep test (TCT) at a temperature range from −20 to +20 °C (in the case of asphalt concrete with styrene-butadiene-styrene (SBS) polymer-modified bitumen from −30 to +20 °C). Two types of neat road bitumen 35/50 and 50/70 and polymer SBS-modified bitumen 45/80–55 were tested for tensile creep properties at low temperatures....
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Autistic Employees’ Technology-Based Workplace Accommodation Preferences Survey—Preliminary Findings
PublicationBackground: There has been an increase in the number of research studies focused on the design of accommodations aimed at improving the well-being and work performance of autistic employees. These accommodations took various forms; some of them were based on modification of management practices, for example, support in the area of effective communication, or involved modifications to the physical working environment aimed at limiting...
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Experimental investigations on the mechanical properties and damage detection of carbon nanotubes modified crumb rubber concrete
PublicationThis study presents a modified crumb rubber (MCR) concrete design mix reinforced with multi-walled carbon nanotubes (MWCNTs), mechanical characterization, and cracking monitoring using the acoustic emission (AE) technique. The results showed that the bridging effect of MWCNTs and MCR in the concrete mix mitigated the shortcomings of MWCNT-MCR concrete and improved the flexural and compressive strengths by 18.3% and 26.5%, respectively,...
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Influence of Giant Reed (Arundo Donax L.) Culms Processing Procedure on Physicochemical, Rheological, and Thermomechanical Properties of Polyethylene Composites
PublicationGiant reed (Arundo donax L.) is a plant species with a high growth rate and low requirements, which makes it particularly interesting for the production of different bioproducts, including natural fibers. This work assesses the use of fibers obtained from reed culms as reinforcement for a high-density polyethylene (HDPE) matrix. Two different lignocellulosic materials were used: i) shredded culms and ii) fibers obtained by culms...
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Effect of bending-torsion on fracture and fatigue life for 18Ni300 steel specimens produced by SLM
PublicationIn this study, different fracture surfaces caused by fatigue failure were generated from 18Ni300 steel produced by selective laser melting (SLM). Hollow round bars with a transverse hole were tested under bending-torsion to investigate the crack initiation mechanisms and fatigue life. Next, the post-failure fracture surfaces were examined by optical profilometer and scanning electron microscope. The focus is placed on the relationship...
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Toolgraph Design of Optimal and Feasible Control Strategies for Time-Varying Dynamical Systems
PublicationArtykuł prezentuje nową metodę projektowania optymalnych i realizowanych strategii sterowania dla wariantnych procesów dynamicznych. Centralnym ośrodkiem i narzędziem tej metody jest struktura grafu przepływowego reprezentująca istotne właściwości autonomicznej dynamiki danego procesu w przestrzeni czasowo-stanowej, składającej się z elementarnych segmentów. Strukturę tę nazywamy grafem narzędziowym przestrzeni czasowo-stanowej....
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On a Recurrence Arising in Graph Compression
PublicationIn a recently proposed graphical compression algorithm by Choi and Szpankowski (2012), the following tree arose in the course of the analysis. The root contains n balls that are consequently distributed between two subtrees according to a simple rule: In each step, all balls independently move down to the left subtree (say with probability p) or the right subtree (with probability 1p). A new node is created as long as...
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The FEM analysis of pressure installation elements after simulated accidental overheating
PublicationThe paper presents innovative analysis focused on the safety aspects of existing pressure installation operation after overheating accidents. Results presented here can be applied in decision-making process concerning further operation of existing pressure installation after cooling system failure. In this paper the results of FEM analysis performed for a straight pipe and 90 degrees elbow, made of super duplex stainless steel,...
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Study of microstress state of P91 steel using complementary mechanical Barkhausen, magnetoacoustic emission, and X-ray diffraction techniques
PublicationThe paper deals with assessment of microstress state of martensite P91 steel using three complementary techniques: mechanical Barkhausen emission, magnetoacoustic emission (MAE), and X-ray diffraction (XRD) profile analysis. Magnetic coercivity Hc and microstructure were investigated with inductive magnetometry and magnetic force microscopy (MFM), respectively. Internal stress level of P91 steel was modified by heat treatment....
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Processing of point cloud data retrieved from terrestrial laser scanning for structural modeling by Finite Element Method
PublicationFinite Element Method is one most popular contemporary method of strength analysis. The method is an advanced method for solving differential equations, based on discretization, which means that area is divided into finite elements. Each finite element has a solution of the equation approximated by specific functions and performing the actual calculations only for nodes of this division. Finite Element Method is widely used in...
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Regulated Assembly of LPS, Its Structural Alterations and Cellular Response to LPS Defects
PublicationDistinguishing feature of the outer membrane (OM) of Gram-negative bacteria is its asymmetry due to the presence of lipopolysaccharide (LPS) in the outer leaflet of the OM and phospholipids in the inner leaflet. Recent studies have revealed the existence of regulatory controls that ensure a balanced biosynthesis of LPS and phospholipids, both of which are essential for bacterial viability. LPS provides the essential permeability...
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THREE-LEVEL F-TYPE INVERTER
PublicationGiven the recent available IGBT switch modules up to 6.5 kV, 1200 A rating, the prospect of the diode-free variant topology of the three-level neutral-point-clamped (3-level, T-type) inverter in certain medium voltage applications is bright; due to its small part count and low conduction losses compared to the diode-clamped NPC inverter. However, within this voltage range, the input dc voltage rating of 50% of the switches per...
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Interactions of telomeric proteins with nucleic acids: sequence recognition on intact and oxidatively damaged telomeres
PublicationTelomeres are complex nucleoprotein assemblies that play a vital role in the maintenance of functional ends of linear chromosomes. Telomeric DNA, composed of tandem repeats of the 5'-TTAGGG-3' motif, solves the so-called end replication problem: as chromosomes shorten with each cell division, no information is lost, and the telomere can be re-extended. In the cell, many protein factors regulate telomere length, nuclear positioning...
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A Flexible Nafion Coated Enzyme‐free Glucose Sensor Based on Au‐dimpled Ti Structures
PublicationThe detection of glucose at low concentrations using electrochemical sensors is of great importance due to the possibility of using different human body fluids than blood, such as e.g. urine, saliva, sweat or tears. The interest behind those biofluids is related to their utility in non-invasive sugar determination. In this work, we present flexible, fully biocompatible electrode material based on Au nanoparticles immobilized onto...
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Nonlinear free and forced vibrations of a dielectric elastomer-based microcantilever for atomic force microscopy
PublicationThe majority of atomic force microcode (AFM) probes work based on piezoelectric actuation. However, some undesirable phenomena such as creep and hysteresis may appear in the piezoelectric actuators that limit their applications. This paper proposes a novel AFM probe based on dielectric elastomer actuators (DEAs). The DE is modeled via the use of a hyperelastic Cosserat model. Size effects and geometric nonlinearity are included...
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Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
PublicationEngineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have...
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X-Ray Computer Tomography Study of Degradation of the Zircaloy-2 Tubes Oxidized at High Temperatures
PublicationThe investigations of high-temperature oxidation of zirconium alloys, applied for fuel pellets in nuclear power plants, are usually limited to oxidation kinetics, phase transformations and microstructural characterization. The purpose of this research was to characterize the degradation phenomena occurring within oxide layer and at the interface oxide/metal, on internal and external Zircaloy-2 tube...
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Investigating the Effects of Ground-Transmitted Vibrations from Vehicles on Buildings and Their Occupants, with an Idea for Applying Machine Learning
PublicationVibrations observed as a result of moving vehicles can potentially affect both buildings and the people inside them. The impacts of these vibrations are complex, affected by a number of parameters, like amplitude, frequency, and duration, as well as by the properties of the soil beneath. These factors together lead to various effects, from slight disruptions to significant structural damage. Occupants inside affected buildings...
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Chitosan-based modalities with multifunctional attributes for adsorptive mitigation of hazardous metal contaminants from wastewater
PublicationThe increase in population and industrialization has intensified water scarcity and stress, and contaminated water bodies. Therefore, the development of advanced water and wastewater treatment technologies has gained global attention from esearchers. Adsorption, using natural materials (nano, polymer, and bio) is one of the most cost-effective, less challenging, and well-known technologies for wastewater treatment and mproving water...
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In Silico Safety Assessment of Bacillus Isolated from Polish Bee Pollen and Bee Bread as Novel Probiotic Candidates
PublicationBacillus species isolated from Polish bee pollen (BP) and bee bread (BB) were characterized for in silico probiotic and safety attributes. A probiogenomics approach was used, and in-depth genomic analysis was performed using a wide array of bioinformatics tools to investigate the presence of virulence and antibiotic resistance properties, mobile genetic elements, and secondary metabolites. Functional annotation and Carbohydrate-Active...
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Interdisciplinary e-collaboration tools / Narzędzia interdyscyplinarnej e-współpracy
PublicationW projektach interdyscyplinarnych niezwykle ważnym czynnikiem jest aktywne konsultowanie i bezpośrednie zastosowanie relatywnie nowo powstałej dziedziny zwanej współpracą interdyscyplinarną. Nawiązywanie interdyscyplinarnej współpracy przynosi wiele korzyści, jednakże niejednokrotnie wiąże się z licznymi problemami i niedogodnościami, a także koniecznością ciągłego doszkalania się i rozszerzania kompetencji zawodowych. Na podstawie...
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Vision guided robot gripping systems
PublicationW rozdziale omawia się robotycki system wykorzystujący kamery streo. System taki zastępuje pracę człowieka przy przenoszeniu obiektów wielkowymiarowych (teoretycznie nieograniczonych) w przestrzeni trójwymiarowej. W rozważaniach uwzględniono pinholową kamerę (bezsoczewkową z bardzo małą aperturą/otworem) oraz prosty model zniekształcenia soczewkowego. Podano wartości poszczególnych parametrów. Zastosowano dwie konwencje notacyjne...
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Behaviour of deformed steel columns exposed to impact load during earthquakes: numerical analysis
PublicationIt has been observed during earthquakes that the so called soft-storey failure of an upper floor of a building leads to considerable vertical impact load acting on structural members of the lower storeys. The aim of this paper is to investigate numerically the behaviour of horizontally deformed columns (deformation as the result of earthquake loading) that are additionally subjected to vertical impact load. In the first stage of...
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Możliwości wykorzystania roślin kapustowatych na potrzeby rolnictwa zrównoważonego na przykładzie kapusty białej
PublicationRośliny kapustowate (Brassicaceae) stanowią najważniejszą grupę roślin o potencjalnym zastosowaniu na dużą skalę w ochronie środowiska. Wynika to głównie z dwóch własności ich fitokompleksu: zdolności wiązania zanieczyszczeń środowiskowych oraz wytwarzania substancji o aktywności skierowanej przeciwko agrofagom. Te cechy spowodowały, że proponuje się rolnicze wykorzystanie roślin kapustowatych w rewitalizacji terenów zdegradowanych...
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Numerical Model of Femur Part
PublicationThe aim of the study is to create a new more accurate method of femur part modelling by using the finite element method. According to this new method, a femur part is treated as a complex structure composed of trabecular bone (internal part) and cortical bone (external part). The internal part is modelled as a scaffold, thus the external part is modelled as a coat (i.e. covering). Applying the programme ABAQUS, there were created...
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Wpływ zaburzeń geometrii na proces wypierania w przestrzeni pierścieniowej otworów wiertniczych
PublicationIzolacja stref zbiornikowych, przenoszenie części naprężeń oraz spowolnienie tempa erozji rur okładzinowych to główne zadania płaszcza cementacyjnego. Powstaje on na skutek stopniowego wyparcia płuczki przez ciecze buforowe, a następnie cieczy buforowych przez zaczyn cementowy. Niepowodzenie tej operacji skutkować może katastrofą na miarę wycieku ropy w Zatoce Meksykańskiej w 2010 roku. Mimo że problem niewystarczającego związania płaszcza...
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Reinforced concrete thin wall dome after eighty years of operation in maritime climate environment
PublicationThe paper presents a description of the construction elements of the Gdynia Seaport main hall dome. Firstly, it provides information about the technical condition of the dome’s structure. Secondly, it examines the strength analysis of the thin-walled reinforced concrete dome covering. Throughout the last 80 years the building has been exposed to an unfavourable marine climate. The analysis of the state of stress and deformations...
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Influence of laser processing of the low alloy medium carbon structural steel on the development of the fatigue crack
PublicationThe paper contains the results of the structural analysis, hardness tests and fatigue tests conducted for the medium carbon structural steel with low content of Cr and Ni after its processing with CO2 laser beam. Pre-cracks were made in the round compact tension (RCT) specimen used for fatigue test. Next, four paths, parallel to each other, were melted on both sides of the samples using a laser beam. The paths were perpendicular...
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Earthquake–induced pounding on response of adjacent structures in series: experimental and numerical study
PublicationPounding between structures in series during earthquakes may cause serious damage in the structur-al elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be called "structures in series". In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including...