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Search results for: DAMAGE STABILITY
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Mechanics of mesh implanted into abdominal wall under repetitive load. Experimental and numerical study
PublicationThere are a number of papers discussing medical and mechanical aspects of ventral hernia management. Despite intensive work on the problem understanding, recurrences of the sickness still happen too often. For that reason new aspects of the problem must be considered. In this paper, a change in the abdominal implant’s stiffness is discussed, which is caused by cyclic loading. Such loading influence abdominal implant e.g. while...
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Economical methods for measuring road surface roughness
PublicationTwo low-cost methods of estimating the road surface condition are presented in the paper, the first one based on the use of accelerometers and the other on the analysis of images acquired from cameras installed in a vehicle. In the first method, miniature positioning and accelerometer sensors are used for evaluation of the road surface roughness. The device designed for installation in vehicles is composed of a GPS receiver and...
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Experimental research on over-laminated steel sandwich panel connection to determine the form of fatigue failure
PublicationThe novel means of transport need to meet rising both the economic and ecologic requirements. In recent years the International Maritime Organization (IMO) introduced new measure of ship energy efficiency (the EEDI index), as well as new regulations regarding higher quality of fuel (so called Tier limits). It resulted in much higher interest of the technological development of ships. One of the solution having great potential is...
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Modelling charge transfer processes in C2+ -tetrahydrofuran collision for ion-induced radiation damage in DNA building blocks
PublicationInvestigations of collision-induced processes involving carbon ions and molecules of biological interest in particular DNA building blocks, are crucial to model the effect of radiation on cells in order to improve medical treatments for cancer therapy. Using carbon ions appears to be one of the most efficient ways to increase biological effectiveness to damage cancerous cells by irradiating deep-seated tumors. Therefore, interest...
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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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EFFECT OF SURFACE STATE AND STRESS ON AN OXIDATION OF THE ZIRCALOY-2 ALLOY
PublicationZr alloys are widely used as materials for nuclear fuel pellets in the nuclear industry. In the case of the LOCA or RIA happen, a temperature may locally reach high values. Even if the high temperature maintains shortly, the zirconium oxides may become permeable, absorb hydrogen appearing in cooling water from decomposition reaction and crack because of formation and brittle failure of hydrides. Such model cannot so far take into...
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Engineering TADF, Mechanochromism, and Second Harmonic Up- conversion Properties in Regioisomeric Substitution Space
PublicationThis research article explores the distinct TADF efficiency of three donor-acceptor based regio-isomers: DPAOCN (ortho- isomer), DPAMCN (meta-isomer), and DPAPCN (para-isomer). DPAPCN exhibits maximum TADF efficiency in both solution and solid-state with an impressive reverse inter-system crossing (RISC) rate of ~ 106 s-1; the underlying cause being the minimum singlet-triplet splitting energy or ∆EST and maximum SOC (spin-orbit...
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Active Diagnostic Experimentation on Wind Turbine Blades with Vibration Measurements and Analysis
PublicationPaper deals with the key operational problems of wind turbosets, especially offshore, where vibrations are generated by rotor blades, as a consequence of erosive wear or icing. The primary causes of the imbalance of wind turbine rotors have been characterised, the observable symptoms of which include various forms of vibrations, transmitted from the turbine wheel to the bearing nodes of the power train components. Their identification...
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Utilizing UAV and orthophoto data with bathymetric LiDAR in google earth engine for coastal cliff degradation assessment
PublicationThis study introduces a novel methodology for estimating and analysing coastal cliff degradation, using machine learning and remote sensing data. Degradation refers to both natural abrasive processes and damage to coastal reinforcement structures caused by natural events. We utilized orthophotos and LiDAR data in green and near-infrared wavelengths to identify zones impacted by storms and extreme weather events that initiated mass...
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The Toolbox of Methods for Multidirectional Characterization of Dietary Nucleic Acids; Verification for Raw and Processed Food Products
PublicationCurrently, the nutritional value of food is associated mainly with components such as proteins, carbohydrates, and lipids. However, another important macromolecules present in many foods are dietary nucleic acids (dietNA), i.e., DNA as well as both coding and non-coding RNAs. In the context of food chemistry and nutrition, dietNA are nowadays vastly neglected. In consequence, there are no dedicated methodologies to characterize...
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Impact of overloaded vehicles on load equivalency factors and service period of flexible pavements
PublicationOverloaded vehicles occur less frequently in comparison to properly loaded vehicles but due to their greater potential to cause damage they significantly contribute to the distress of pavement structure. As the studies show, the phenomena of vehicles overloading intensifies when the control of traffic is poor and the average percentage of overloaded vehicles on analyzed roads varies from 6% to 23%. The main goal of the ar-ticle...
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Changes in Epigenetic Patterns Related to DNA Replication in Vicia faba Root Meristem Cells under Cadmium-Induced Stress Conditions
PublicationExperiments on Vicia faba root meristem cells exposed to 150 µM cadmium chloride (CdCl2) were undertaken to analyse epigenetic changes, mainly with respect to DNA replication stress. Histone modifications examined by means of immunofluorescence labeling included: (1) acetylation of histone H3 on lysine 56 (H3K56Ac), involved in transcription, S phase, and response to DNA damage during DNA biosynthesis; (2) dimethylation of histone...
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The comparison of cytotoxic and genotoxic activities of glucosinolates, isothiocyanates, and indoles
PublicationChemopreventive properties of Brassica vegetables are attributed mainly to their characteristic compounds—glucosinolates (GLs) and their main hydrolysis products—isothiocyanates (ITCs) and indoles. In this study, we compared antiproliferative activity (MTT test in HT29 cells) and genotoxic effects (comet assay in HT29 cells and restriction analysis in a cell-free system) of three GLs (sinigrin (SIN), glucotropaeolin (GTL), and...
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Investigating the disease- modifying properties of sclerotiorin in Alzheimer's therapy using acetylcholinesterase inhibition
PublicationAlzheimer's disease (AD) is a progressive neurodegenerative disorder caused due to the damage and loss of neurons in specific brain regions. It is the most common form of dementia observed in older people. The symptoms start with memory loss and gradually cause the inability to speak and do day-to-day activities. The cost of caring for those affected individuals is huge and is probably beyond most developing countries capability....
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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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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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Genotoxic properties of glucosinolates and isothiocyanates present in Brassica vegetables
PublicationThe bioactive phytochemicals found in Brassica vegetables, in this number glucosinolates (GLS), as well as products of their degradation such as isothiocyanates (ITC) and indoles, are regarded as the most promising chemopreventive compounds. These secondary metabolites display stron antibiological activity and constitute defence system preventing the development of agrophages attacking Brassica plants. Such properties suggest...
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DNA methylation in cancer development, diagnosis and therapy-multiple opportunities for genotoxic agents to act as methylome disruptors or remediators
PublicationThe role of DNA methylation and recently discovered hydroxymethylation in the function of the human epigenome is currently one of the hottest topics in the life sciences. Progress in this field of research has been further accelerated by the discovery that alterations in the methylome are not only associated with key functions of cells and organisms, such as development, differentiation and gene expression, but may underlie a number...
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Dominant Pathways of Adenosyl Radical-Induced DNA Damage Revealed by QM/MM Metadynamics
PublicationBrominated nucleobases sensitize double stranded DNA to hydrated electrons, one of the dominant genotoxic species produced in hypoxic cancer cells during radiotherapy. Such radiosensitizers can therefore be administered locally to enhance treatment efficiency within the solid tumor while protecting the neighboring tissue. When a solvated electron attaches to 8-bromoadenosine, a potential sensitizer, the dissociation of bromide...
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An Experimental Investigation of Pressure Wave Celerity During the Transient Slurry Flow
PublicationTransportation of slurries in pressure pipelines is an example of a complex flow due to specific parameters of transported medium. For practitioners, the economy of designing and maintenance is usually the most important factor. For this reason, most of hydrotransport installations are fairly simple; however, they become more vulnerable to negative effects of the transient flow which can occur in pressure pipelines. As the consequence,...
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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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The reliability of any-hop star networks with respect to failures of communication nodes.
PublicationThis paper investigated the reliability of any-hop star networks. The any-hop star topology is used in centralized computer networks. We will assume that the all nodes fail independently, links are failure-free. Following measures of network reliability are assumed: the expected number of nodes, which can communicate with the central node; the expected number of node pairs, which are connected by a path through the central node;...
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Pounding Between Superstructure Segments in Multi-Supported Elevated Bridge with Three-Span Continuous Deck Under 3D Non-Uniform Earthquake Excitation
PublicationReports after severe ground motions show that the earthquake-induced structural pounding may lead to significant damage in elevated bridges. The aim of this paper is to analyse pounding between superstructure segments of a highway elevated bridge with three-span continuous deck under 3D non-uniform earthquake excitation, which is induced by spatial seismic effects related to the propagation of seismic wave. The conditional stochastic...
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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...
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Polygons vs. clumps of discs: A numerical study of the influence of grain shape on the mechanical behaviour of granular materials
PublicationWe performed a series of numerical vertical compression tests on assemblies 01 20 granular material using a Discrete Element code and studied the results with regard to the grain shape. The samples consist of 5000 grains made from either 3 overlapping discs (clumps - grains with concavities) or six-edged polygons (convex grains). These two grain type have similar external envelope, which is a fund ion of a geometrical parameter...
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Linking of adjacent three-storey buildings for mitigation of structural pounding during earthquakes
PublicationThe reports after major earthquakes indicate that the earthquake-induced pounding between insufficiently separated buildings may lead to significant damage or even total collapse of structures. An intensive study has recently been carried out on mitigation of pounding hazards so as to minimize the structural damages or prevent collisions at all. The aim of this paper is to investigate the effectiveness of the method when two adjacent...
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The New 3D Printed Left Atrial Appendage Closure with a Novel Holdfast Device: A Pre-Clinical Feasibility Animal Study
PublicationMany patients undergoing cardiac surgery have risk factors for both atrial fibrillation and stroke. The left atrial appendage (LAA) is the primary site for thrombi formation. Therefore LAA occlusion devices should be tested for their ability to reduce future cerebral ischemic events in patients with high-risk of haemorrhage. The aim of this study was to evaluate the safety and feasibility of a novel left atrial appendage exclusion...
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Algorithm for Automatic Wear Estimation of Railway Contact Strips Based on 3D Scanning Results
PublicationElectric rail vehicles use current collection system which consists of overhead contact line and a current collector (pantograph) mounted on the roof of a vehicle. A pantograph is equipped with contact strips, which slide along the contact wire, ensuring steady electric contact. Contact strips are made of carbon layer, fixed to an aluminum carrier. The carbon layer wears down due to friction. Using overly worn contact strips increases...
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Novel anticancer strategy aimed at targeting shelterin complexes by the induction of structural changes in telomeric DNA: hitting two birds with one stone.
PublicationThe ends of chromosomes in mammals are composed of telomeric DNA containing TTAGGG repeats, which bind specific proteins called shelterins. This telomeric DNA together with shelterins form a cap that protects the ends of chromosomes from being recognized as sites of DNA damage and from chromosomal fusions. Many very successful antitumor drugs used in the treatment of cancer patients bind to DNA, some of them with a prominent sequence...
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Quantumness in Diagnostics of Marine Internal Combustion Engines and Other Ship Power Plant Machines
PublicationThe article provides proof that the diagnostics of marine internal combustion engines and other ship power plant machines should take into account the randomness and unpredictability of certain events, such as wear, damage, the variations of mechanical and thermal loads, etc., which take place during machine operation. In the article, the energy E, like the other forms (methods) that it can be converted into (heat and work), is...
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CHEMOTHERAPY-MEDIATED COMPLICATIONS OF WOUND HEALING. AN UNDERSTUDIED SIDE EFFECT
PublicationSignificance: Chemotherapy is a primary method to treat cancer, but while cytotoxic drugs are designed to target rapidly dividing cancer cells, they can also affect other cell types, including dermal cells and macrophages involved in wound healing, which often leads to the development of chronic wounds. The situation becomes even more severe when chemotherapy is combined with surgical tumor excision. Recent advances: Despite its...
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Relationship between Chemical Structure and Biological Activity Evaluated In Vitro for Six Anthocyanidins Most Commonly Occurring in Edible Plants
PublicationNumerous studies have provided evidence that diets rich in anthocyanins show a broad spectrum of health benefits. Anthocyanins in nature are usually found in the form of glycosides. Their aglycone forms are called anthocyanidins. The chemical structure of anthocyanins is based on the flavylium cation, but they differ in the position and number of substituents. However, the bioactives and foods that contain them are frequently treated...
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Transport of dangerous goods by rail, and threats to the subsoil of the railway surface in the event of a disaster
PublicationIn Poland, in 2020, the mass of dangerous goods (loads) transported by rail was 26 151.06 thousand tone. This translated into the performance of 8 899 691.89 thousand tone - km of transport performance. In 2020, these figures accounted for 11.72% of the weight of goods transported by rail. The situation is similar in other countries around the world. With such a large volume of transport of dangerous...
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Determination of stepped plate thickness distribution using guided waves and compressed sensing approach
PublicationGuided waves recently have attracted significant interest as a very promising research area. The signals registered by a specially designed sensor network are processed to assess the state of the tested structure. Despite the constant development of novel damage detection algorithms employing guided waves, the phenomenon of wave propagation still needs detailed recognizing and understanding for the further progress of non-destructive...
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Impact of slow breathing on the blood pressure and subarachnoid space width oscillations in humans
PublicationThe aim of the study was to assess cardiac and respiratory blood pressure (BP) and subarachnoid space (SAS) width oscillations during the resting state for slow and fast breathing and breathing against inspiratory resistance. Experiments were performed on a group of 20 healthy volunteers (8 males and 12 females; age 25.3 ± 7.9 years; BMI = 22.1 ± 3.2 kg/m2). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography....
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Drill holes decrease cancellous bone strength: A comparative study of 33 paired osteoporotic human and 9 paired artificial bone samples
PublicationThis study was designed to compare compressive strength of cancellous bone retrieved from the femoral head in a specimen with and without guide wire hole, with comparison to synthetic bone samples. Femoral heads retrieved from 33 patients who sustained femoral neck fractures and underwent hip arthroplasty were cut into cuboids leaving two matching samples from the same femoral head. Similar samples were prepared from synthetic femurs....
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BPL-PLC Voice Communication System for the Oil and Mining Industry
PublicationApplication of a high-efficiency voice communication systems based on broadband over power line-power line communication (BPL-PLC) technology in medium voltage networks, including hazardous areas (like the oil and mining industry), as a redundant mean of wired communication (apart from traditional fiber optics and electrical wires) can be beneficial. Due to the possibility of utilizing existing electrical infrastructure, it can...
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Repeated Projectile Impact Tests on Multi-Layered FibrousCementitious Composites
PublicationThis research aims to experimentally evaluate the behaviour of multi-layered fibrous cementitious composites withintermediate Glass Fibre Meshes (GFM) under repeated projectile load. The impact load was subjected through a convexedge projectile needle at a low velocity on cylindrical specimens of three-layered fibrous cementitious composites, whichhave two different steel fibre distributions. In series A mixtures, a constant steel...
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Hydraulic analysis of causes of washout of Gdynia-Orłowo seashore during the flood in the Kacza river estuary
PublicationIn July 2016 in the Three-city agglomeration a rainfall episode of over a day duration and 150 mm summary rainfall height, occurred. This situation, extreme as for Polish conditions, caused significant freshets in rivers and streams running into Gdansk Bay, the Baltic Sea, and serving as collectors of rainfall waters for the sea-coast towns. In many areas of the Three-city flood phenomena and overflows took place. The flood also...
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Degradation of ferritic X10CrAlSi18 stainless steel caused by slurry
PublicationThe slurry erosion tests of ferritic X10CrAlSi18 steel were carried out using a slurry pot device. In order to investigate the erosion process, two series of tests were performed: first one with a constant impact velocity of 5 m/s, 7 m/s and 9 m/s and the second one, during which the impact velocity was changed after every exposure. During each test, an influence of test conditions on volume loss, surface hardness and roughness...
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Fatigue fracture morphology of AISI H13 steel obtained by additive manufacturing
PublicationThe paper focuses on researching the effect of fatigue loading on metallic structure, lifetime, and fracture surface topographies in AISI H13 steel specimens obtained by selective laser melting (SLM). The topography of the fracture surfaces was measured over their entire area, according to the entire total area method, with an optical three-dimensional surface measurement system. The fatigue results of the SLM 3D printed steel...
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EVALUATION OF EFFECTIVENESS OF WATERJET PROPULSOR FOR A SMALL UNDERWATER VEHICLE
PublicationT he goal of the project described is to replace the existing propulsion system of a small underwater vehicle with a solution less prone to mechanical damage and ensuring a lower risk of the entanglement of fibrous objects suspended in the body of water. Four typical marine screws are utilised in the current design of the vehicle. One possible solution of the problem is the application of waterjet propulsors located...
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Fatigue of titanium alloy Ti6Al4V with diamond structure obtained by Laser Power Bed Fusion method
PublicationThis paper presents the results of fatigue tests conducted on Ti6Al4V titanium alloy with diamond structure obtained by the Laser Power Bed Fusion method. Samples used in tests were printed with porosities: 81%, 73%, 50%, 34% and near-zero porosity. Samples were subjected to cyclic tests with a constant stress amplitude. The number of cycles until sample failure was registered. Obtained fatigue test results made it possible to...
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Mitigating the seismic pounding of multi-story buildings in series using linear and nonlinear fluid viscous dampers
PublicationSeismic-induced pounding between adjacent buildings may have serious consequences, ranging from minor damage up to total collapse. Therefore, researchers try to mitigate the pounding problem using different methods, such as coupling the adjacent buildings with stiff beams, connecting them by using viscoelastic links, and installing damping devices in each building individually. In the current paper, the effect of using linear and...
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Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study
PublicationLiterature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite...
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Incremental dynamic analysis and fragility assessment of buildings founded on different soil types experiencing structural pounding during earthquakes
PublicationThe effect of the soil type on buildings experiencing pounding during earthquakes is investigated in this study using the incremental dynamic analysis and fragility assessment methods. Three 3-D structures with different number of storeys (4, 6 and 8) were considered in this study. Three pounding scenarios between these three buildings were taken into account, i.e. pounding between 4-storey and 6-storey buildings, between 4-storey...
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Advanced fatigue and rutting characterisation of Polish asphalt mixtures based on the VECD model and viscoplastic shift model
PublicationThe advanced asphalt mixture performance-related specifications (AM-PRS) recently developed in USA can allow an optimisation of the design process of asphalt pavements thanks to the possibility to fully take into account the intrinsic material properties. In this study, four typical Polish mixtures, i.e. a Stone Mastic Asphalt (SMA) for wearing course, two mixtures for binder course with neat bitumen or Polymer modified Bitumen...
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Seismic performance evaluation of steel buckling-restrained braced frames including SMA materials
PublicationThe permanent deformation of the building after seismic excitations can be determined by the Maximum Residual Interstory Drift Ratio (MR-IDR), which may be used for measuring the damage states. Low-post yield stiffness of the steel buckling-restrained braced frame (BRBF) makes this system vulnerable to large MR-IDR after a severe earthquake event. To overcome this issue, this paper investigates the seismic limit state performances...
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Optimum shapes and dimensions of rubber bumpers in order to reduce structural pounding during seismic excitations
PublicationLarge displacement of structures observed during seismic excitations may lead to collisions between two adjacent, insufficiently-separated buildings and may result in major damages of both of them. In many building codes, appropriate equations or approximately recommended distances between structures in order to avoid pounding hazard have been introduced. Unfortunately, further, more detailed considerations show that safety situation...
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Bitumen Aging—Laboratory Simulation Methods Used in Practice and Selected Directions of Research on New Methods
PublicationChanges in the properties of bitumen binders that occur as a result of aging have a huge impact on the durability of products produced from them. In particular, asphalt pavements, which constitute the most common use of petroleum bitumen, are susceptible to damage resulting from the increasing stiffness of the bitumen during its life cycle. Increased stiffness of asphalt pavements reduces the pavement resistance to low-temperature...