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Search results for: CROWD LOAD
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Wind tunnel experiments and numerical analysis of the wind load on double-shell cylindrical, vertical tanks
PublicationW pracy przedstawiono wyniki badań modelowych w tunelu aerodynamicznym oraz symulacji komputerowych obciążenia wiatrem pionowych, walcowych zbiorników dwupłaszczowych z dachem pływającym. W badaniach modelowych analizowano wpływ rozstawu między płaszczami zbiornika na wartość i rozkład współczynnika ciśnienia na płaszczach oraz dachu pływającym. Wyniki symulacji komputerowych przeprowadzonych w programie Fluent porównano z wynikami...
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Susceptibility of the LLC Resonance Generator for Induction Heating on Changes in Load Parameters Caused by Heating the Charge
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Pelvic vertical shear fractures: The damping properties of ligaments depending on the velocity of vertical impact load
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Analysis of the influence of geometrical imperfections on the equivalent load stabilizing roof truss with lateral bracing system
PublicationThe paper is focused on the numerical analysis of the stability and load bearing capacity of a flat steel truss. The structure was supported by elastic lateral braces. The translational and rotational brace stiffness was taken into account. The linear buckling analysis were performed for the beam and shell model of the truss. The nonlinear static analysis were conducted for the structure initial geometric imperfections. As a result...
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A Novel Coupling Matrix Synthesis Technique for Generalized Chebyshev Filters With Resonant Source–Load Connection
PublicationThis paper reports a novel synthesis method for microwave bandpass filters with resonant source–load connection. In effect, a network realizing N+1 transmission zeros (where N is the number of reflection zeros) is obtained. The method is based on a prototype transversal coupling matrix (N+2, N+2) with source and load connected by a resonant circuit formed by a capacitor in parallel with a frequency-invariant susceptance. To complement...
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Determination of Equivalent Axle Load Factors on the Basis of Fatigue Criteria for Flexible and Semi-Rigid Pavements
PublicationArtykuł przedstawia analizę współczynników równoważności obciążenia osi na podstawie kryteriów zmęczeniowych stosowanych w mechanistyczno-empirycznych metodach projektowania nawierzchni. Określono wzory służące do obliczania współczynnika w oparciu o szereg kryteriów zmęczeniowych. Podano wartości liczbowe współczynników.
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Steady-state characteristics and dynamic response of the PEM fuel cell to unit step change of load
PublicationPodano opis układu zasilania opartego na dwóch ogniwach paliwowych typu PEM o łącznej mocy 2.4 kW. Zaprezentowano wybrane charakterystyki statyczne i dynamiczne układu.
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Load test of new European record holder in span length among extradosed type bridges
PublicationThe article presents acceptance load tests of a newly built extradosed MS-3 bridge located along the national road DK-16 near Ostróda (Poland). The structure features significant dimension in European reference scale. It is a new record holder in span length regarding this distinct bridge category. Its length ranges 206 m. Static and dynamic load tests were performed here. The program was extended by entire structural laser scanning...
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Communication and Load Balancing Optimization for Finite Element Electromagnetic Simulations Using Multi-GPU Workstation
PublicationThis paper considers a method for accelerating finite-element simulations of electromagnetic problems on a workstation using graphics processing units (GPUs). The focus is on finite-element formulations using higher order elements and tetrahedral meshes that lead to sparse matrices too large to be dealt with on a typical workstation using direct methods. We discuss the problem of rapid matrix generation and assembly, as well as...
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The Effect of Flexible Pavement Mechanics on the Accuracy of Axle Load Sensors in Vehicle Weigh-in-Motion Systems
PublicationWeigh-in-Motion systems are tools to prevent road pavements from the adverse phenomena of vehicle overloading. However, the effectiveness of these systems can be significantly increased by improving weighing accuracy, which is now insufficient for direct enforcement of overloaded vehicles. Field tests show that the accuracy of Weigh-in-Motion axle load sensors installed in the flexible (asphalt) pavements depends on pavement temperature...
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Improving the procedure of probabilistic load testing design of typical bridges based on structural response similarities
PublicationThis paper concerns load testing of typical bridge structures performed prior to operation. In-situ tests of a two-span post-tensioned bridge loaded with three vehicles of 38-ton mass each formed the input of this study. On the basis of the results of these measurements, an advanced FEM model of the structure was developed for which the sensitivity analysis was performed for chosen uncertainty sources. Three uncorrelated random...
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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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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublicationThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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Non-Linear Analysis of Structures Utilizing Load-Discretization of Stiffness Matrix Method with Coordinate Update
PublicationThis paper proposes a stiffness method based structural analysis algorithm for geometrically non-linear structures. In this study, the applied load on the joints has been discretized to a sequence of a few loadings applied. Each loading step produces incremental external nodal displacements, which are added to the corresponding coordinates to get a new geometrical shape of the structure. This process is iteratively repeated until...
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Problem of optimal load distribution between generators minimizing risk of enegretic ship system overload.
PublicationOmówiono system rozdziału mocy czynnych pomiędzy generatorami w systemie energetycznym statku. Minimalizuje się ryzyko przeciążeń systemu przy jednoczesnej minimalizacji kosztów wytwarzania energii w systemie.
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Monitoring Lead Concentration in the Surrounding Environmental Components of a Lead Battery Company: Plants, Air and Effluents—Case Study, Kenya
PublicationLead (Pb) pollution from smelters and lead–acid battery has become a serious problem worldwide owing to its toxic nature as a heavy metal. Stricter regulations and monitoring strategies have been formulated, legislated and implemented in various parts of the world on heavy metal usage. Developed countries such as the USA and in Europe largely operate within the set standards, however, developing countries such as Kenya, Nigeria...
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Tools for road infrastructure safety management in poland
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Mercury loads into the sea associated with extreme flood
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Sensitivity analysis of critical loads of I-columns
PublicationThe first order variation of critical buckling load of thin-walled columns with bisymmetric open cross-section due to some variations of the design variables such as: cross-section dimensions, or material characteristics is derived. The influence of the residual welding stresses is taken into account. In the numerical examples dealing with I-column the functions describing the effect of the variation of the dimensions of the flange...
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Prevention methods and tools in road designing and maintenance
PublicationSpośród wielu systemowych elementów zarządzania bezpieczeństwem infrastruktury drogowej, wyróżnić można cztery rodzaje działań mające charakter prewencyjny, a mianowicie: Ocena oddziaływania na bezpieczeństwo ruchu, Audyt bezpieczeństwa ruchu drogowego, Zarządzanie bezpiecezństwem sieci drogowej i Przeglądy dróg. Działania te, jako środki prewencyjne w projektowaniu i eksploatacji dróg powinny stanowić spójny system ocen projektowanych...
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Tire/road noise - generation, measurement, and abatement
PublicationPodano określenia i definicje dotyczące hałasu opon samochodowych. Omówiono mechanizmy generowania tego hałasu oraz zasady modelowania. Przedstawiono metody pomiaru hałasu opon oraz stosowane systemy pomiarowe. Podano normy dotyczące hałasu opon. Omówiono wpływ opony i nawierzchni na hałas generowany przez toczące się koło ogumione. Zaprezentowano koła kompozytowe oraz opony z bieżnikiem poroelastycznym generujące niski poziom...
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The structure of liquid lead: EXAFS and MD studies
PublicationPraca poświecona jest analizie widm XAFS zmierzonych na krawędzi L3dla ciekłego ołowiu. W analizie strukturalnej EXAFS zastosowano podejście GNXAS. Przetestowano kilka modeli strukturalnych, zarówno numerycznych (MD-DLE, MD-TB), jak i tych otrzymanych doświadczalnie (ND, XRD) i ostatecznie zrekonstruowano pierwszy pik w parowej funkcji rozkładu, g(r). Zweryfikowano wcześniejsze doniesienia o obserwownym za pomocą metody XAFS gwałtownym...
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Tire rolling resistance measurements on the road and in the laboratory
PublicationW pracy przedstawiono stanowisko bębnowe do badania oporu toczenia opon samochdowych w warunkach laboratoryjnych. Zaprezentowano także przyczepę dynamometryczną do badania oporu toczenia opon samochodowych w warunkach drogowych. Stanowisko bębnowe i przyczepa zosały zbudowane w Katedrze Pojazdów i Maszyn Roboczych Politechniki Gdańskiej. Omówiono wpływ wzdłużnego pochylenia drogi i naporu powietrza na badane koło na dokładność...
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Cadmium and lead toxicity and bioaccumulation in Microcystis aeruginosa
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Study on polymer modified road asphalt mixture
PublicationThe formulation of ternary asphalt-additives blend composed of crumb rubber : low-density polyethylene (CR : LDPE) and crumb rubber : textile fiber (CR : TF) couples, and quaternary asphalt additives-blend composed of (CR : LDPE : TF) triplets on the virgin asphalt to optimize the asphalt basic and rheological properties and to use the extrusion process of two or three additives to obtain composite materials of them, as well as...
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CFFT columns in road through railroad crossings
PublicationThere were 12801 road through railroad one-level crossings in Poland in 2018. 215 accidents happened at them in 2018. In order to increase safety in rail and road traffic two-level crossings should be used. They are definitely safer and make the traffic more smooth. In the design and construction of two-level intersections of railway and road or path columns of circular cross-section are often used. They can be successfully replaced...
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Measurement of the muon stopping power in lead tungstate
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Road texture influence on tyre rolling resistance
PublicationTyre performance, one of the critical factors for vehicle users, is strongly related to theroad surface characteristics, most notably to the pavement texture. Phenomena that occur at the tyre/road interface affect tyre friction (skid resistance), rolling resistance, tyre wear and tyre/road noise. This article deals with relationship between surface texture and rolling resistance of light and heavy vehicle tyres. Mean profile depth...
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Regional implementation of a road safety observatory in Poland
PublicationThe paper outlines the background and goals of the Road Safety Observatory in the Polish region of Warmia and Mazury. While created it was Poland’s first road safety Observatory, both at the regional and central level. Established in line with the methodology proposed in the European project SafetyNet, together with the planned National Road Safety Observatory it will form part of a Europe-wide network of observatories linked with...
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Ultra Low Noise Poroelastic Road Surfaces
PublicationNoise is one of the most important environmental problems related to road traffic. During the last decades, the noise emitted by the engines and powertrains of vehicles was greatly reduced and tires became a clearly dominant noise source. The article describes the concept of low noise poroelastic road surfaces that are composed of mineral and rubber aggregate bound by polyurethane resin. Those surfaces have a porous structure and...
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Hierarchical random models in road transport safety
PublicationIn this paper multilevel approach to the issue of road safety level on the road network of European regions, classified as NUTS 2 in statistical databases of the EU, has been presented. The risk calculated as the number of death casualties in road accidents per 100,000 inhabitants of a given region has Poisson distribution. Therefore, generalized Poisson model has been assumed in the modelling process. Multilevel stochastic analysis...
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Road texture influence on tire rolling resistance
PublicationTire rolling resistance is one of the most important resistive forces acting on road vehicles. It depends on tire and surface characteristics as well as vehicle operating parameters. This paper deals with the influence of road surface texture on rolling resistance of passenger car tires. Results of road measurements performed on variety of road surfaces are presented.
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PERS - QUIET ROAD SURFACE FOR URBAN AREAS
PublicationTraffic noise is one of the most important environmental problems in densely populated urban areas. At low speeds the tyre/road interaction dominates all other sources. It is anticipated that when electric and hybrid vehicles gain dominance in city traffic, the importance of tyre/road noise will still increase as electric engines are much less noisy than combustion engines. On the other hand, electric and hybrid urban vehicles...
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Mobile system for on-road measurements of air pollutants
PublicationW pracy zaprezentowano prototyp mobilnej stacji diagnostycznej do pomiarów stężeń typowych zanieczyszczeń powietrza (C6H6, NO2, NOx, CO i CO2) pochodzących z komunikacji w miastach. Nowością proponowanego systemu jest możliwość przeprowadzania pomiarów emisji zanieczyszczeń wzdłuż ciągów komunikacyjnych i w miejscach, w których nie mogą być zastosowane stacjonarne stacje monitoringowe. W proponowanym rozwiązaniu, urządzenie...
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An application of acoustic sensors for the monitoring of road traffic
PublicationAssessment of road traffic parameters for the developed intelligent speed limit setting decision system constitutes the subject addressed in the paper. Current traffic conditions providing vital data source for the calculation of the locally fitted speed limits are assessed employing an economical embedded platform placed at the roadside. The use of the developed platform employing a low-powered processing unit with a set of microphones,...
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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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Assessment of Road Restraint Systems in Polish Conditions
PublicationKey to understanding the needs and tools of road infrastructure management is identifying the hazards and their sources involved in having no or faulty road restraint systems. Clarity is also needed on why the systems are wrongly designed, constructed, built and operated. To ensure that the problem is adequately understood, research and site observations were conducted and...
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INFLUENCE OF MEASURING CONDITIONS ON TYRE/ROAD NOISE
PublicationA decisive factor for the development of tyres and road surfaces is the ability to conduct representative and reproducible measurements of selected characteristics related to the interaction of tyres and road surfaces. In terms of tyre/road noise measurements in Europe two methods described in ISO/FDIS 11819-2 and ECE Regulation No.117 are used. The latter is compulsory for assigning the tyre noise labels. The methodologies differ...
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Pavement ageing influence on tyre/road noise
PublicationRoad surface should be constructed in a way that ensures safe and comfortable traffic conditions, not only when it is newly paved but also during its entire lifetime. An important factor in the asphalt mixture design process is also the expected pavement durability and stability of pavement properties over time. In many countries, road surface starts to play a significant role in traffic noise reduction actions. Selecting a particular...
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ROAD SAFETY FOR CYCLISTS BASED ON THE CALORIES NEEDED
PublicationCyclists are a vulnerable group of road users, especially when no separate infrastructure for cyclists is provided. Then, road factors such as distance and altitude differences can indirectly affect cyclists' safety. Therefore, the authors proposed a procedure based on the geometric characteristics of the road that can determine riding difficulties for cyclists. The proposed procedure can be used both by the public authorities who...
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Tools for road infrastructure safety management in Poland
PublicationThe objective of road safety infrastructure management is to ensure that when roads are planned, designed, built and used road risks can be systematically identified, assessed, removed and mitigated. There are a number of approaches to road safety management. European Union Directive 2008/96/EC requires EU member states to use four basic tools of road safety infrastructure management. An overview of the methods in these countries...
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The effects of vehicle restraint systems on road safety
PublicationKey to understanding the needs and tools of road infrastructure management for preventing run-off-road crashes or minimising their consequences, is to identify the hazads and sources of hazards caused by wrong or improper use of road safety devices and identify errors in the desifn, structure, construction and operation of road safety devices. Studying such an extended scope of the problem required fieldwork and surveys with road...
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The Effects of Roadside Hazards on Road Accident Severity
PublicationThe risk of becoming involved in an accident emerges when elements of the transport system do not operate properly (man – vehicle – road – roadside). The road, its traffic layout andsafety equipment have a critical impact on road user safety. This gives infrastructural work a priority in road safety strategies and programmes. Run-off-road accidents continue to be one of the biggest problems of road safety with consequences including...
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Optimal ECG lead for deriving respiratory signal
PublicationEDR is an interesting measuring technique that allows an indirect assessment of respiratory activity. This is an alternative solution to direct methods that are based on the measurement of air flow, which require a specialized sensor or even a system. However, due to inter-personal anatomical differences, the optimal ECG lead (placement of the electrodes) ensuring the best EDR signal quality is not fixed. An influence of ECG lead...
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Electrical conductivity of reduced lead-germanate glasses
PublicationPewna grupa szkieł tlenkowych poddana procesowi redukcji w atmosferze gorącego wodoru wykazuje gwałtowne zmiany swoich właściwości elektrycznych i optycznych. Szkła ołowiowo-germanianowe, którym poświęcona jest niniejsza praca należą do takich szkieł i charakteryzują się szczególnymi redukcyjnie indukowanymi właściwościami. Wystarczająco długie wygrzewanie prowadzi bowiem do wzrostu przewodnictwa elektrycznego nawet o 12 rzędów...
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Loads on walls and inserts in a mass-flow silos
PublicationArtykuł przedstawia numeryczną symulację przepływu materiału sypkiego w silosach z uwzględnieniem wkładki silosowej o kształcie podwójnego stożka. Pokazany został wpływ zamontowanej wkładki na rodzaj przepływu oraz na wartość i kształt naporu na ścianę silosu.
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Arterial stiffness increases in response to an acute arterial load challenge induced by an isometric handgrip in healthy individuals
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Bearing capacity of piles based on static load tests and calculation principles provided by EN 1997-1
PublicationW artykule scharakteryzowano i przeanalizowano ogólne zalecenia Eurokodu 7 dotyczące wyznaczania nośności pali na podstawie próbnych obciążeń statycznych. Porównano je z zaleceniami dotychczasowej polskiej normy PN-83/B-02482. Przedstawiono kilka przykładów interpretacji rzeczywistych wyników próbnych obciążeń pali według zaleceń wyżej wymienionych dwóch norm wraz z analizą porównawczą.
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Influence of energy absorbers on Malgaigne fracture mechanism in lumbar-pelvic system under vertical impact load
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Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
PublicationOne of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was...