Wyniki wyszukiwania dla: FOUR-POINT BENDING TEST
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Nitrogen transformation during fermentation in agricultural biogas plants
PublikacjaThe aim of the present study was to determine changes in the organic nitrogen fraction in the liquid fraction of the digestate during laboratory tests of mono- and co-digestion. Three agricultural wastes were tested: distillery residue, cattle slurry and corn silage. In the mono-fermentation tests, the initial total nitrogen concentration depended on the feedstock used. As a result of the hydrolysis and ammonification of the organic...
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Functionalization of Parylene During Its Chemical Vapor Deposition
PublikacjaTwo possible mechanisms for the reaction of four halogenated (metha)acrylate-based molecules with Parylene [poly (paraxylylene)] during its chemical vapor deposition were proposed. The chemical reactivity of acrylate double bond with the paraxylylene biradical was calculated for all four (metha)acrylate-based molecules. These calculations allowed the evaluation of the energetically favorable mechanism and indeed a direct correlation...
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Potential Toxic Effects of Airport Runoff Water Samples on the Environment
PublikacjaDespite the positive aspects of the intensive development of aviation, airports are considered large-scale polluters. Pollution caused by runoff water (stormwater) is one of the major problems related to airport operations. The aim of this study was to characterize the potential toxic impact on aquatic life from runoff water discharges from four international airports in Europe. Samples of stormwater were collected at airports...
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Detection and size estimation of crack in plate based on guided wave propagation
PublikacjaThe paper presents results of the comprehensive theoretical and experimental investigation of crack detection in metallic plate using guided wave propagation. The main aim of the paper is to develop the novel method which would allow for linear crack size estimation with the use of minimal number of the transducers. In general, there exists the relation between length of the propagation path and the wave amplitude value. However,...
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Parallel Computations of Text Similarities for Categorization Task
PublikacjaIn this chapter we describe the approach to parallel implementation of similarities in high dimensional spaces. The similarities computation have been used for textual data categorization. A test datasets we create from Wikipedia articles that with their hyper references formed a graph used in our experiments. The similarities based on Euclidean distance and Cosine measure have been used to process the data using k-means algorithm....
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Application of probabilistic tools to extend load test design of bridges prior to opening
PublikacjaLoad tests of bridges are widely performed in a large number of countries. Deterministic comparison of measurement results to the theoretical, FEM (finite element method)-based outcomes with possible further calibration is mostly applied. Sometimes, the data collected in the tests are also used to calibrate the reliability factors of bridge structures or their components. This work proposes to complement the stage of the load test...
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Diagnostic Model of Crankshaft Seals
PublikacjaT he paper presents a research stand being a diagnostic model of radial lip seals used, among others, on crankshafts of piston combustion engines in order to identify the correctness of their operation. The possibility of determining the technical condition of lip seals on the basis of the proposed coefficient of correctness of operation has been described. T he basic features of seals influencing their correctness of...
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Time-Gating method with automatic calibration for accurate measurements of electrically small antenna radiation patterns in Non-Anechoic environments
PublikacjaNon-anechoic sites represent a cheap alternative to measurements of antennas in dedicated facilities. However, due to a high noise—from the external EM signal sources and multipath interferences—the quality of radiation patterns obtained in non-anechoic conditions is poor. The characteristics can be corrected using a time-gating method (TGM), which involves filtering of the noise based on temporal analysis of the measured signals....
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Development of proximity in cluster organizations
PublikacjaSustainable development in cluster organizations (COs) is most fully manifested in the synergy effect. In turn, the synergy effect is achieved thanks to the development of proximity among cluster entities. The purpose of the paper is to test two conceptual models reflecting relations between selected dimensions of proximity in cluster organizations. The author reports the findings of a quantitative study conducted in four COs....
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Human memory enhancement through electrical stimulation in the temporal cortex
PublikacjaDirect electrical stimulation of the human brain can elicit sensory and motor perceptions as well as recall of memories. Stimulating higher order association areas of the lateral temporal cortex in particular was reported to activate visual and auditory memory representations of past experiences (Penfield and Perot, 1963). We hypothesized that this effect could be used to modulate memory processing. Recent attempts at memory enhancement...
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Self-Censorship in a Workplace: The Role of Gender, Management Position, Procedural Justice and Organizational Climate
Dane BadawczeData consist of three studies. In study 1 (N = 948) we test whether women manifest more self-censorship than men and we verify whether this effect is maintained when women and men hold managerial position. Then, we analyse the effects of procedural justice (study 2, N = 98) and communal organizational climate (study 3, N = 567) on women’s and men’s...
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THERMAL ANALYSIS AND DESIGN OF HYBRID MICROCHANNEL-MICROJET TEST PROBE
PublikacjaThe paper presents the numerical investigation of a microjet- microchannel cooling module. In which microjets of water are impinging into the microchannels and forming a liquid film on the impingement surface. Applied technology takes benefits from two very attractive heat removal techniques. When lminar jets are impinging on the surface have a very high kinetic energy at the stagnation point, also in microchannels boundary layer...
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NEW SOLUTIONS FOR THE SOLAR CHARGE CONTROLLERS DESIGN FOR OBTAINING TRUE MPP IN PARTLY SHADED PV MODULES
PublikacjaSoft shading sources such as tree limbs, structural elements of buildings and chimneys, scatter and refract sunlight, significantly reducing the amount of radiation reaching the surface of the module. The hard shadings located directly on the surface (i.e. bird droppings, leaves, snow) tend to stop sunlight completely. These phenomena significantly affects the output characteristics of photovoltaic modules and often contribute...
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COMPARATIVE ANALYSIS OF POINT CLOUDS OBTAINED BY TLS AND PHOTOGRAMMETRY
PublikacjaTechnical progress in the field of 3D modelling resulted in increasing use of such technics to create a virtual 3D models of objects. Three-dimensional spatial models are used in a wide range of applications such as inventorisation of architectural-construction, an inventorisation of archaeological sites, medicine and wide-known engineering. Spatial models are created based on the point clouds acquired with laser scanners or photogrammetry....
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Point cloud in archaeological and historical survey
PublikacjaIn the last decade the potential of using the point clouds in archaeological research has been noted. Therefore, a number of guidelines concerning aspects of data acquisition (resolution and format) were developed. They also included the way of searching the imaged area to identify archaeological and historical cultural heritage sites. The purpose of this research was to analyze the point cloud for selected woodland survey. Forest...
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Computer-assisted assessment of learning outcomes in the laboratory of metrology
PublikacjaIn the paper, didactic experience with broad and rapid continuous assessment of students’ knowledge, skills and competencies in the Laboratory of Metrology, which is an example of utilisation of assessment for learning, is presented. A learning management system was designed for manage, tracking, reporting of learning program and assessing learning outcomes. It has ability to provide with immediate feedback, which is used by the...
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Measurement of benzene concentration in urban air using passive sampling
PublikacjaAbstract The concentration of benzene in urban air in theTri-City area of Poland (Gdańsk-Sopot-Gdynia, andTczew) was assessed using diffusive passive samplers (Rad-iello). Samples were collected during a four-year monitoringcampaign (2007-2010) at selected monitoring stations man-aged by the Agency of Regional Air Quality Monitoring inthe Gdańsk Metropolitan Area (ARMAAG) Foundation.The performance of the passive samplers was investigatedin...
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Analysis of thoracic regional impedance changes using PCA approach
PublikacjaA multichannel impedance and one lead electrocardiographic recording system has been developed. The impedance measurement unit is built using a four-electrode technique. It consists of a sinusoidal, 40 kHz, current source and five measurement channels. Circumferential current electrodes have been located at a neck and an abdomen. Voltagemeasurement disk electrodes formed five two-electrode measurement ports. The impedance change...
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Accelerated Re-Design of Antenna Structures Using Sensitivity-Based Inverse Surrogates
PublikacjaThe paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant reduction of the number of reference designs required to render the surrogate. Rigorous formulation of the approach is supplemented by its comprehensive numerical validation using a...
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Preeclampsia Risk Prediction Using Machine Learning Methods Trained on Synthetic Data
PublikacjaThis paper describes a research study that investigates the use of machine learning algorithms on synthetic data to classify the risk of developing preeclampsia by pregnant women. Synthetic datasets were generated based on parameter distributions from three real patient studies. Four models were compared: XGBoost, Support Vector Machine (SVM), Random Forest, and Explainable Boosting Machines (EBM). The study found that the XGBoost...
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Investigation of Liquid–Gas Flow in a Horizontal Pipeline Using Gamma-Ray Technique and Modified Cross-Correlation
PublikacjaThis article presents the application of the radioisotope absorption method in the study of two-phase water–air flow in a horizontal pipe. The measurement principle and the test stand are briefly described. The main part of the article presents the signal analysis methods applied to data obtained from scintillation detectors. Because these signals are mostly stochastic waveforms, they were analyzed statistically using the cross-correlation...
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THE METHOD OF ENERGY-EFFICIENCY INVESTIGATIONS OF THE NEWLY PRODUCED MARINE FUELS THROUGH AN APPLICATION OF THE LABORATORY DIESEL ENGINE
PublikacjaThe article deals with one of the scientific issue solved within frames of the research project financed by Voivodeship Fund for Environmental Protection and Water Management in Gdansk, namely, in particular, the method of energy investigations of the self-ignition engine in conditions of its supply with a non-standard (modified) marine fuel. The representative results of engine tests worked out on the especially built laboratory...
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Photocatalytic activity of nitrogen doped TiO2 nanotubes prepared by anodic oxidation: The effect of applied voltage, anodization time and amount of nitrogen dopant
PublikacjaNitrogen doped TiO2 nanotube arrays were prepared by anodizing Ti foils in an organic electrolyte containing specified amounts of urea as nitrogen precursor. The photocatalytic activity of the samples was evaluated by analyzing the degradation kinetics of phenol in water. The influence of tubes’ length, tubes’ surface morphology and amount of nitrogen in the TiO2 lattice on hydroxyl radical formation efficiency, photocatalytic...
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Reliability model of slide bearings with particular attention given to lubricating oil
PublikacjaThe paper presents the slide bearing with circulating lubrication as a system of series three-element structure, where lubricating oil is the weakest link. In accordance with the Pierce statement that ''strength of chain is the strength of its weakest link'', a bearing reliability model has been developed. It allows to use the lubricating oil to evaluate the probability of correct working of the whole slide bearing, i.e. the reliability....
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Low-frequency noise in ZrS3 van der Waals semiconductor nanoribbons
PublikacjaWe report the results of the investigation of low-frequency electronic noise in ZrS3 van der Waals semiconductor nanoribbons. The test structures were of the back-gated field-effect-transistor type with a normally off n-channel and an on-to-off ratio of up to four orders of magnitude. The current–voltage transfer characteristics revealed significant hysteresis owing to the presence of deep levels. The noise in ZrS3 nanoribbons...
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Detection of debonding in adhesive joints using Lamb wave propagation
PublikacjaAdhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form...
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Non-destructive Testing of Wooden Elements
PublikacjaExamining the condition of wooden elements is crucial from the perspective of proper structure performance. If the deterioration in the internal wood condition, which displays no symptoms visible from the outside, is detected, the further spread of the deterioration can be prevented. Test results often point to the necessity of conducting repairs and, renovations, replacing the structure of wooden beams, or even substituting a...
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Psychometric properties of the Bern illegitimate tasks scale using classical test and item response theories
PublikacjaCombining a classical test theory and an item response theory (IRT), this study aimed to investigate the psychometric properties of the Bern Illegitimate Tasks Scale (BITS) by measuring two conceptually separate dimensions capturing unnecessary tasks (perceived by employees as pointless) and unreasonable tasks (perceived as unfairly or inappropriately assigned). Data collected among Polish employees in two samples (N= 965 and N=...
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The influence of the carbon equivalent on the weldability of high-strength low-alloy steel in the water environment
PublikacjaFrom many years, the high strength low alloy steels are often used for offshore constructions. This constructions, due to the environment in which they work, require more frequent repairs than the constructions from the land. For economic reasons, repairs take place in the underwater conditions, however water significantly decreases the weldability of steel. The paper presents the results of the CTS weldability test for S460ML...
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Drug-Eluting Biopsy Needle as a Novel Strategy for Antimicrobial Prophylaxis in Transrectal Prostate Biopsy
PublikacjaOBJECTIVES: To preclinically evaluate drug-eluting biopsy needles (patent pending WO2016118026) as a new potential way of antimicrobial prophylaxis for transrectal prostate biopsy. METHODS: Twenty steel biopsy needles have been coated with polyvinyl alcohol, ciprofloxacin, and amikacin. Modified biopsy needles have been randomly divided into 3 groups (1:2:1 ratio). Needles from group I were immersed for 30 minutes in dedicated...
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A quasi-2D small-signal MOSFET model - main results
PublikacjaDynamic properties of the MOS transistor under small-signal excitation are determined by kinetic parameters of the carriers injected into the channel, i.e., the low-field mobility, velocity saturation, mobility at the quiescent-point (Q-point), longitudinal electric field in the channel, by dynamic properties of the channel, as well as by an electrical coupling between the perturbed carrier concentration in the channel and the...
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A simple test for quantum channel capacity
PublikacjaBased on state and channel isomorphism we point out that semidefiniteprogramming can be used as a quick test for nonzero one-way quantum channelcapacity. This can be achieved by searching for symmetric extensions of statesisomorphic to a given quantum channel. With this method we provide examplesof quantum channels that can lead to high entanglement transmission but stillhave zero one-way capacity, in particular, regions of symmetric...
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Performance of a hybrid microjet – microchannel cooling module
PublikacjaThe paper presents the experimental investigation of a microjet- microchannel cooling module. In which microjets of water are impinging into the microchannels and forming a liquid film on the impingement surface. Applied technology takes benefits from two very attractive heat removal techniques. When lminar jets are impinging on the surface have a very high kinetic energy at the stagnation point, also in microchannels boundary...
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Interaction Between Storm Water Conduit Flow and Overland Flow for Numerical Modelling of Urban Area Inundation
PublikacjaNowadays we can observe increasing frequency of inundations in cities. This makes accurate predicting of inundations more important than ever. Numerical modeling of this issue requires complex approach with simultaneous calculations of pipe flow and surface flow. In this paper, after a short review of known methods used for solving pipe and surface flow, we will try to answer the question if presented methods would be sufficiently...
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Tripping of F-type RCDs for High-Frequency Residual Currents
PublikacjaResidual current devices (RCDs) are apparatus commonly used for protection against electric shock in low-voltage electrical installations. They protect people in the case of an earth fault or even in the case of direct contact with the live parts. However, to be effective protective devices, RCDs have to detect residual currents of various waveform shapes which appear in modern electrical installations. For this purpose, RCDs...
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Tripping of F-type RCDs for high-frequency residual currents
PublikacjaResidual current devices (RCDs) are apparatus commonly used for protection against electric shock in low-voltage electrical installations. They protect people in the case of an earth fault or even in the case of direct contact with the live parts. However, to be effective protective devices, RCDs have to detect residual currents of various waveform shapes which appear in modern electrical installations. For this purpose, RCDs are...
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Impact performance of novel multi-layered prepacked aggregate fibrous composites under compression and bending
PublikacjaMulti-layered Prepacked aggregate fibrous composite (MLPAFC) is a new type of concrete, which is prepared in two subsequent stages of aggregate-fibre skeleton prepacking and cementitious grouting. In this study, ten MLPAFC mixtures were prepared in three subsequent layers incorporating different contents of four different types of steel fibres. Long and short hooked-end and crimped steel fibers were adopted with 3.0 and 1.5% dosages...
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On-line measurement of wood surface smoothness
PublikacjaThe latest progress in the field of optics and microelectronics resulted in development of new generation vision systems capable of scanning surface topography with very high sampling frequencies. The blue color of illuminating light as well as novel systems for controlling ultra-thin laser line thickness allows measurement of the porous surface of wood with a triangulation method. Three alternative sensors were tested here in...
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Quality of Cryptocurrency Mining on Previous Generation NVIDIA GTX GPUs
PublikacjaCurrently, there is a lot of previous generation NVIDIA GTX graphical processing units (GPUs) available on the market, which were ousted from by next-gen RTX units. Due to this fact, numerous fully-operational devices remain underused, which are available at an affordable price. First, this paper presents an analysis of the cryptocurrency market. Next, in this context, the results of research on the performance of NVIDIA graphics...
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Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublikacjaThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
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Performance Comparison of a 650 V GaN SSFET and CoolMOS
PublikacjaThe new technology of wide band gap semiconductors is said to outperform up-to-date silicon devices. High voltage Gallium Nitride (GaN) transistors, now emerging in the market, have even three times shorter switching times and even four times smaller energy losses compared to the best in-class Si devices. In this paper the performance of a 650 V GaN SSFET is evaluated and compared with the newest silicon family of CoolMOS™ technology....
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Odour Perception Using a Sniffing Team at a Municipal Solid Waste Treatment Plant: A Case Study
PublikacjaThe monitoring of odour intensity, generated by a landfill area, is a difficult activity since it is a multi-source problem with discontinuous odour emissions. A modified sniffing team method is described here and applied to determine the main odour sources in a landfill located in Pomerania, Poland. Four consecutive test sessions were performed during the following months: August, December, April, and June. It was found that the...
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Determination of Odor Intensity of Binary Gas Mixtures Using Perceptual Models and an Electronic Nose Combined with Fuzzy Logic
PublikacjaMeasurement and monitoring of air quality in terms of odor nuisance is an important problem. From a practical point of view, it would be most valuable to directly link the odor intensity with the results of analytical air monitoring. Such a solution is offered by electronic noses, which thanks to the possibility of holistic analysis of the gas sample, allow estimation of the odor intensity of the gas mixture. The biggest problem...
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Analyzing energy/performance trade-offs with power capping for parallel applications on modern multi and many core processors
PublikacjaIn the paper we present extensive results from analyzing energy/performance trade-offs with power capping observed on four different modern CPUs, for three different parallel applications such as 2D heat distribution, numerical integration and Fast Fourier Transform. The CPU tested represent both multi-core type CPUs such as Intel⃝R Xeon⃝R E5, desktop and mobile i7 as well as many-core Intel⃝R Xeon PhiTM x200 but also server, desktop...
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Trigger-based Model to Assess the Readiness of IT Organizations to Agile Transformation
PublikacjaThe process of change the method of project management from waterfall to agile is called “agile transformation” (AT). The decision to agile transformation is undertaken based on many different factors. Many companies decide to abandon classic, waterfall methodology for agile without prior analysis. This approach makes the processes of agile transformation is hard to control and frequently the implementation of agile fails. The...
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Shape memory thin films of Polyurethane: Does graphene content affect the recovery behavior of Polyurethane nanocomposites?
PublikacjaThin nanocomposite films of polyurethane have received remarkable attention due to their shape memory properties. As most of the reports focus on the beneficial aspects of the presence of nanofillers such as graphene nanoplatelets (GNPs) introduced into shape memory polymers, some research results reveal the opposite trend. The polyether/polyester-based polyurethane was synthesized through a condensation polymerization and the...
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An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater
PublikacjaThe paper presents a new analytical four‑layer (air–water–bottom–non‑conductive layer) horizontal electric dipole model which allows an accurate approximation of ship’s Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of...
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Influence of laser processing of the low alloy medium carbon structural steel on the development of the fatigue crack
PublikacjaThe 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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Suspended-sediment transport related to ice-cover conditions during cold and warm winters, Toudaoguai stretch of the Yellow River, Inner Mongolia, China
PublikacjaThe presence of winter ice in cold regions changes the water level, flow rate, velocity distribution, and other parameters of the river, which in turn affects the sediment concentration and channel evolution. Based on data obtained from Toudaoguai Hydrological Station from 1959 to 2021, this study examines the characteristics of the ice regime during cold and warm winters and the water and sediment transport processes along the...
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Wear estimation of current collector contact strips by analysis of a 3D scanning results
PublikacjaThe technical condition of current collector contact strips is very important when operational reliability of railway transportation is considered. The authors proposed a novel measurement system based on a 3D camera to register the shape and dimensions of the current collector contact strips surface. The system was installed above the railway track for tests in target ambient. During the trial operation a few dozen of contact...