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Wyniki wyszukiwania dla: PILE TOE RESISTANCE
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Cavitation Erosion Resistance Influence of Material Properties
PublikacjaThe cavitation erosion is the phenomena that causes degradation of fluid flow machinery components due to repetitive implosion of cavitation bubbles adjacent to the solid surface. Cavitation erosion is a complex phenomenon, which includes not only hydrodynamic factors of liquid, but also properties of erodible material e.g. microstructure, hardness or Young modulus. In order to reduce the negative impact of erosion on machine components,...
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Shear resistance of low height precast concrete lintels
PublikacjaThe scope of the paper is to investigate analytically and determine experimentally the shear resistance of low height reinforced precast concrete lintels. The chosen procedures included in national and international standards applied for the design of structural concrete elements to an estimation of shear behaviour of reinforced concrete elements are described. The characteristic and designed shear strength of precast concrete...
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The influence of road surface unevenness on tyre rolling resistance
PublikacjaThe geometric characteristics of road surface substantially affect the interaction between tyre and road. Depending on pavement texture wavelength, the texture chiefly affects tyre/road friction, rolling resistance, interior and exterior noise, tyre wear, and ride comfort. The article presents results of investigations on the influence of road surface unevenness on the rolling resistance of passenger car and truck tyres. The tests...
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Antimicrobial resistance of fecal indicators in disinfected wastewater
PublikacjaThe main objective of the study was to assess the potential of three systems (UV irradiation, ozonation, and micro/ultrafiltration) operated in a pilot scale in removal of antimicrobial-resistant fecal bacteria from secondary effluent of the local wastewater treatment plant (700,000 population equivalent). The effectiveness of the processes was analysed using the removal ratio of fecal indicators (Escherichia coli and Enterococcus...
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Selected Aspects of Pavement Texture Influence on Tire Rolling Resistance
PublikacjaTire rolling resistance has a significant influence on fuel consumption in cars and trucks and on CO2 emissions. Rolling resistance depends on the tire construction, pavement texture and stiffness, as well as environmental and traffic conditions. This article presents a pilot study on the impact of pavement texture on the rolling resistance of passenger car tires. Reasons why Mean Profile Depth is not a good descriptor of pavement...
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Fecal indicators resistance to antimicrobial agents present in municipal wastewater
PublikacjaIn this study removal rate of six antimicrobial compounds (belonging to folate pathway inhibitors and macrolides class) was analyzed in processes of local wastewater treatment plant (WWTP) together with susceptibility patterns of erythromycin (E) resistant Enterococcus spp. and trimethoprim/sulfamethoxazole (SXT) resistant Escherichia coli. According to the obtained data, six of tested antimicrobial agents, namely erythromycin,...
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The resistance of S235JR steel to cavitation erosion
PublikacjaThe erosion resistance of S235JR steel to flow cavitation was investigated. In order to understand an influence of steel properties and cavitation intensities on the degradation mechanisms, low-carbon S235JR steel was tested in the as-received state and after thermal treatment (annealing) under four different flow velocities. Annealing decreased steel hardness, which made S235JR steel less resistant to cavitation erosion. The performed...
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Detection of sulfonamide resistance genes via in situ PCR-FISH
PublikacjaDue to the rising use of antibiotics and as a consequence of their concentration in the environment an increasing number of antibiotic resistant bacteria is observed. The phenomenon has a hazardous impact on human and animal life. Sulfamethoxazole is one of the sulfonamides commonly detected in surface waters and soil. The aim of the study was to detect sulfamethoxazole resistance genes in activated sludge biocenosis by use of...
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The Effect of Full-Cell Impregnation of Pine Wood (Pinus sylvestris L.) on Changes in Electrical Resistance and on the Accuracy of Moisture Content Measurement Using Resistance Meters
PublikacjaThe impact of the full-cell impregnation of pine wood was investigated with respect to changes in electrical resistance and the accuracy of moisture content measurement. This study compared the resistance of impregnated and untreated pine timber harvested from the northern part of Poland (Pomeranian region). The wood was impregnated by the vacuum-pressure method. The preservative (TANALITH E 3475) and coloring (TANATONE 3950) agents...
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Impact of the surface evenness and texture on tire/road rolling resistance
PublikacjaThis paper deals with the issue of a surface's roughness and texture impact on tire/road rolling resistance. It includes a brief description of research aims, measurements and an analysis of results. It also presents observations and conclusions regarding drum facility modernisation which allows studies concerning surface's roughness and texture impact on tire/road rolling resistance.
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Antimicrobial resistance of fecal indicators in muncipal wastewater treatment plant
PublikacjaAntimicrobial resistance of fecal coliforms (n = 153) and enterococci (n = 199) isolates was investigated in municipal wastewater treatment plant (WWTP) based on activated sludge system. The number of fecal indicators (in influent and effluent as well as in the aeration chamber and in return activated sludge mixture) was determined using selective media. Susceptibility of selected strains was tested against 19 (aminoglycosides,...
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Comparative model tests of SDP and CFA pile groups in non-cohesive soil
PublikacjaThe research topic relates to the subject of deep foundations supported on continuous flight auger (CFA) piles and screw displacement piles (SDP). The authors have decided to conduct model tests of foundations supported on the group of piles mentioned above and also the tests of the same piles working alone. The tests are ongoing in Geotechnical Laboratory of Gdańsk University of Technology. The description of test procedure, interpretation...
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DESIGN AND CALIBRATION OF ROLLING RESISTANCE TEST TRAILER R2mk.2
PublikacjaThe paper describes construction nad calibration procedures of the rolling resistance test trailer R2 Mk2. The trailer is design to measure rolling resistance of passenger car tyres in various road conditions on trafficked road. The trailer utilizes so called angle method also known as vertical arm method. The paper presents also calibration procedures that are necessary to ascertain good precision of the measurements.
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The impact of material degradation on the resistance and reliability of truss structures
PublikacjaThe paper analyses limit load-carrying capacity and buckling load of truss towers used to support high voltage power lines. The analysed typical structure was subjected to characteristic loads and their combinations. The results were applied to assess structural resistance with regard to steel corrosion in the long-term operation. The extent of structural deterioration was assessed due to Young's modulus decrement in the course...
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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Review of Selected Methods for Prediction of Added Resistance in Following Waves
PublikacjaThe added resistance in waves is a mean value of non-linear, second order reaction of a ship to incoming waves. In the beginning of the 20th century, the experimental methods for investigation of ship hydrodynamics at model scale were developed. They allowed the evaluation of added resistance by measurements in irregular waves (directly) or by measurements in regular waves (in-direct method). The main goal was to find more precise...
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Verification of the criteria for evaluation of water and frost resistance of asphalt concrete
PublikacjaThe paper presents the results of field investigation - condition survey of existing pavements and the results of laboratory tests on water and frost resistance of samples cored from the these pavements. The purpose of testing was to verify the criteria for evaluation of the resistance of asphalt concrete to the action of water and frost by way of comparing the results of field and laboratory tests, followed by evaluation of their...
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Reduction of Tire Rolling Resistance by Optimization of Road Surfaces and Tires
PublikacjaDuring interaction between tire and road surface three very important phenomena are always in effect. One of them (very desirable) is friction that is important for traction, braking and cornering. Two other phenomena are not desirable at all, that is rolling resistance and noise. This paper discusses relations between road surface and tire parameters versus tire rolling resistance. Road surface texture, porosity, impedance, strength...
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Identification and antimicrobial resistance of Enterococcus spp. isolated from surface water
PublikacjaIn the study species distributions and antimicrobial resistance profiles were determined among riverine Enterococcus spp. Susceptibility of the isolates was tested against: ampicillin, imipenem, teicoplanin, vancomycin, erythromycin, linezolid, fosfomycin, ciprofloxacin,levofloxacin, moxifloxacin, tetracycline, high levels of gentamicin and streptomycin. The enterococci were detected in all of the analyzed water samples, periodically...
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Resistance is futile
PublikacjaOmówiono zasadę działania przyczepy dynamometrycznej służącej do pomiaru oporu toczenia opon do samochodów osobowych i dostawczych w warunkach drogowych. Przyczepa ta została zbudowana w Katedrze Pojazdów i Maszyn Roboczych Politechniki Gdańskiej. Zaprezentowano wyniki dadań oporu toczenia dwóch opon na nawierzchni SMA 0/12,8.
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Reduction of noise and rolling resistance by horizontal grinding of asphalt pavements
PublikacjaGrinding of cement concrete pavements to reduce unevenness and noise is common since a long time. Grinding is then made with wheels equipped with diamond blades rotating in the vertical plane. This creates narrow vertical/longitudinal grooves in the pavement. It is not applied to asphalt pavements. In this paper an alternative type of grinding is studied. In this case plates with diamond heads rotate in the same plane as the pavement,...
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Method of estimating the rolling resistance coefficient of vehicle tyre using the roller dynamometer
PublikacjaThe tendency in the past few years has been to introduce tyres with lower rolling resistance coefficients to the market. This paper presents a mathematical method for determining the rolling resistance coefficients variation depending on the speed. The method uses power balance which results from automobile dynamics while rolling on chassis dynamometer. The rolling resistance coefficients of tyres obtained through ‘drum test method’,...
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Polymer based thick films - material quality and interface resistance evaluation
PublikacjaThe properties of polymer based thick film layers mede using different resistive pastes and dipping silvers have been studied. The composite of carbon and graphite (C/Gr) conducting particles suspended in different polymer vehicles were used for preparation resistive layers. Interface resistance Rc created between dipping silver (DiAg) contact layer and resistive layer was determined from the surface potential distribution measurements...
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Antibiotic resistance in wastewater, does the context matter? Poland and Portugal as a case study
PublikacjaAntibiotic resistance has been considered a major human health threat that may endanger the success of medicine. Recent studies have unveiled worldwide asymmetries of antibiotic resistance occurrence, being factors as diverse as climate, socioeconomic, or antibiotic use possible drivers of such asymmetric distribution. In Europe, where clinical antibiotic resistance is surveyed for more than 20 years, the European Center for Disease...
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Prediction of ship resistance with the use of Full-scale CFD simulations
PublikacjaIn recent years, the IMO has introduced new regulations to reduce the negative impact of ships on the natural environment. A particularly important step forcing technological innovations is the increasing requirement of ship energy efficiency. It is expressed by the Energy Efficiency Design Index (EEDI). Another important step towards green shipping is rising the required quality of fuel used for propulsion, so called Tier limits....
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In-situ and ex-situ resistance measurements of polypyrrole film using double-band electrode
PublikacjaMany in-situ techniques are performed in order to determine the resistance of conducting polymer film. However, the resistance measured in solution can be the combination of polymer resistance and that of other components, such as resistance of supporting electrolyte. Therefore, in this work, the influence of the solution on the resistance of polypyrrole (PPy) film has been studied. PPy film was electrchemically synthesized onto...
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Atimicrobial Resistance of Enterococcus spp. in Muncipal wasterwater Treatment Plant - Model Study
PublikacjaIn this study the removal of resistant Enterococcus spp. was evaluated using the laboratory-scale wastewater treatment model plant (M-WWTP), designed as a multiphase (anaerobic, anoxic and aerobic) system (Q = 27 dm3 per day) and continuously supplied with the wastewater obtained from the full-scale WWTP, after grid. The activated sludge from the secondary clarifier was recirculated to the anaerobic chamber (with the ratio equal...
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Evidence of mutations conferring resistance to clarithromycin in wastewater and activated sludge
PublikacjaThe occurrence of clarithromycin in wastewater samples and of the activated sludge bacteria possibly resistant to this pharmaceutical was the object of the study. Samples of wastewater or activated sludge were taken from a municipal wastewater treatment plant in summer and winter and characterised regarding their clarithromycin concentrations and the presence of nucleic acid fragments (Cla-sequences) known to be responsible for...
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Hydraulic resistance analyses of selected elements of the prototype Stirling engine
PublikacjaThe paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration...
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TIRE/ROAD NOISE AND TIRE ROLLING RESISTANCE ON PROTOTYPE PERS SURFACE
PublikacjaPoroelastic road surfaces are characterized by low noise of tires running on them.Road pavements of this type are promising solution to problems related to traffic noise in cities and on rural roads. Some technical problems still have to be solved, in particular regarding durability and skid resistance on wet surface. Ongoing and planned works are to contribute to create a quiet, durable and safe road surface, which will become...
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New approaches to cutting resistance estimation of wood cutting process with circular-saw blades
PublikacjaTheoretical and experimental determination of values of cutting resistance belongs to the basic and simultaneously the most developed field of mechanics of this process. Energetic effects of wood sawing process are mainly calculated on the basis of the specific cutting resistance which, in wood cutting, is a function on a lot of factors. In this paper new method for calculation of cutting resistance is described. The latter method...
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Experimental validation of the rolling resistance measurement method including updated draft standard
PublikacjaThe main objective of ROSANNE is the harmonisation and standardisation of the measurement of skid resistance, noise emission and rolling resistance of road pavements. Regarding rolling resistance characterisation, a draft for standardization of a harmonized procedure for classification of road surfaces across Europe has been prepared within WP3 (deliverable 3.5). The procedure deals with the direct measurement on real roads of...
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INFLUENCE OF WRONGLY ASSUMED PROBABILITY DISTRIBUTION ON THE UNCERTAINTY OF RESISTANCE MEASUREMENT BY TECHNICAL METHOD
PublikacjaThe paper presents studies on the influence of probability distributions on the expanded uncertainty of the resistance measurement. Choosing the correct probability distribution is very important to estimate of measurement uncertainty. The most commonly used distribution is the rectangular distribution. The paper presents the results of analysis of the resistance measurement uncertainty using the technical method of two resistances:...
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Rolling resistance and tyre/road noise on rubberised asphalt pavement in Poland
PublikacjaThe paper presents results of tyre/road noise and rolling resistance measurements performed on stone mastics asphalt (SMA) that contains rubberised asphalt, developed and produced by a refinery in Poland. Bituminous binder was modified with polymer and addition of crumb rubber. The first observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger...
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Rolling Resistance And Tire/Road Noise on Rubberized Asphalt Pavement In Poland
PublikacjaThe paper presents results of tire/road noise and rolling resistance measurements performed on stone-matrix asphalt (SMA) that contains rubberized asphalt developed and produced by the company in Poland. Bituminous binder was modified with polymer and additive of crumb rubber. First observations of asphalt mixture with the new kind of modified bitumen used on the field section are presented. Rolling resistance of passenger car...
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Thin-walled cross section shape influence on steel member resistance.
PublikacjaThis work describes why trending thin-walled technology is achieving popularity in steel construction sector. A purpose of this article is to present the influence of the cold-formed element cross-section shape on an axial compression and a bending moment resistance. The authors have considered four different shapes assuming constant section area and thickness. Calculations were based on three different steel grades taking into...
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Cavitation Erosion Resistance of Austenitic Stainless Steel after Glow-Discharge Nitriding Process
PublikacjaThis paper presents investigation of cavitation erosion resistance of nitrided austenitic stainless steel X5CrNi18-10. The diffusion layers were produced by using different parameters of atmosphere (N2:H2). The microstructure, chemical composition and phase identification of the modified layer were examined using scanning electron microscopy, glow-discharge optical emission spectrometer and X-ray diffractometry, respectively. Cavitation...
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Antimicrobial resistance of Pseudomonas spp. isolated from wastewater and wastewater-impacted marine coastal zone
PublikacjaIn this study, species distribution and antimicrobial susceptibility of cultivated Pseudomonas spp. were studied in influent (INF), effluent (EFF), and marine outfall (MOut) of wastewater treatment plant (WWTP). The susceptibility was tested against 8 antimicrobial classes, active against Pseudomonas spp.: aminoglycosides, carbapenems, broad-spectrum cephalosporins from the 3rd and 4th generation, extended-spectrum penicillins,...
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Impact resistance of plain and twill fabric in GFRP measured by active thermography
PublikacjaThis paper discusses the impact resistance of glass-fibre reinforced polymer (GFRP) composites depending on the type of reinforcement – plain or twill weave. The values of impact energy were: 3J, 10J and 15J. Specimens featuring twill weave transferred higher force during the impact as compared with plain weave specimens. It was observed that an increase of impact energy was accompanied by an increase of the disproportion in...
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Mechanisms of azole resistance among clinical isolates of Candida glabrata in Poland
PublikacjaCandida glabrata is currently ranked as the second most frequently isolated aetiological agent of human fungal infections, next only to Candida albicans. In comparison with C. albicans, C. glabrata shows lower susceptibility to azoles, the most common agents used in treatment of fungal infections. Interestingly, the mechanisms of resistance to azole agents in C. albicans have been much better investigated than those in C. glabrata....
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Evaluation of Wear Resistance of Ti alloys used for elements friction of knee endoprosthesis
PublikacjaThe paper presents research results of resistance to abrasive wear of titanium alloys: Ti6Al4V (commonly used) and Til3Nb13Zr (alloy of new generation) in association with polyethylene (UHMW-PE) predisposed for elements on pair of the knee endoprosthesis. The results were analysed from the point of possibility of an use of new generation titanium alloys as components of such implants. The tests of resistance to abrasive wear of...
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Field Evaluation of High Modulus Asphalt Concrete Resistance to Low-Temperature Cracking
PublikacjaHigh-modulus asphalt concrete has numerous advantages in comparison to conventional asphalt concrete, including increased resistance to permanent deformations and increased pavement fatigue life. However, previous studies have shown that the construction of road pavements with High Modulus Asphalt Concrete (HMAC) may significantly increase the risk of low-temperature cracking. Those observations were the motivation for the research...
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Transport deficiency is the molecular basis of Candida albicans resistance to antifungal oligopeptides
Publikacja(FMDP), an inhibitor of glucosamine-6-phosphate synthase, exhibited growth inhibitory activity against Candida albicans, with minimal inhibitory concentration values in the 0.05–50 mg/L range. Uptake by the peptide permeases was found to be the main factor limiting an anticandidal activity of these compounds. Di- and tripeptide containing FMDP (F2 and F3) were transported by Ptr2p/Ptr22p peptide transporters (PTR) and FMDP-containing...
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The Effect of Posaconazole, Itraconazole and Voriconazole in the Culture Medium on Aspergillus fumigatus Triazole Resistance
PublikacjaTriazoles are the only compounds used as antibiotics in both medicine and agriculture. The presence of triazoles in the environment can contribute to the acquisition of azole resistance among isolates of Aspergillus fumigatus. The objective of this study was to investigate the effect of A. fumigatus exposure to triazoles on susceptibility to these compounds. Seventeen triazole-resistant and 21 triazole-sensitive A. fumigatus isolates...
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Resistance of Escherichia coli and Enterococcus spp. to selected antimicrobial agents present in municipal
PublikacjaIn this study, the susceptibility to erythromycin (E) and to trimethoprim/sulfamethoxazole (SXT) among isolates of Enterococcus spp. and Escherichia coli was tested, respectively. Both fecal indicators were detected and isolated from raw(RW) and treated wastewater (TW) as well as from samples of activated sludge (AS) collected in a local wastewater treatment plant (WWTP). Biodiversity of bacterial community in AS was also monitored...
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Effects of the preheating laser treatment on microstructure and corrosion resistance of Ti6Al4V bioalloy
PublikacjaThe laser remelting of the Ti6Al4V alloy was made on specimens pre-heated at elevated temperatures. The laser treatment effected in change of microstructures of surface layers and an appearance of blisters and numerous cracks. The corrosion tests demonstrated the decrease in corrosion resistance for each preheating temperature. The observed effects were attributed to negative influence of excessive compressive stresses with no...
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Effect of the Post-Weld Surface Condition on the Corrosion Resistance of Austenitic Stainless Steel AISI 304
PublikacjaSurfaces of welded elements made of corrosion-resistant (stainless) steels develop temper colours. The removal of thickened oxide layers off steels exposed to temperatures below 300°C is necessary and entails the restoring of high corrosion resistance of the stainless steel. The article presents tests concerned with the effect of a method applied to remove post-weld temper on the corrosion resistance of austenitic stainless steel...
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Influence of bitumen type on cracking resistance of asphalt mixtures used in pavement overlays
PublikacjaCracking is one of the predominant distresses occurring in flexible pavements, especially in old pavements that were rehabilitated with an asphalt overlay. In such cases asphalt mixtures should be designed to ensure high resistance to reflective cracking because new asphalt layers are exposed to existing cracks of the old pavement. The nature of these cracks can be various (transverse, longitudinal as well as crazy cracking). One...
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Multi-objective weather routing of sailboats considering wave resistance
PublikacjaThe article presents a method to determine the route of a sailing vessel with the aid of deterministic algorithms. The method assumes that the area in which the route is to be determined is limited and the basic input data comprise the wind vector and the speed characteristic of the vessel. Compared to previous works of the authors, the present article additionally takes into account the effect of sea waves with the resultant resistance...
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The influence of inflation pressure and ambient temperature on the value of the truck tires rolling resistance
PublikacjaThe articlediscusses the effect of inflation pressure and the ambient temperature on the value of the rolling resistance of truck tires which directly translates into fuel consumption. For this purpose, a series of measurements was made at two ambient temperatures (at 25°C and -15°C), using different pumping pressures.