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Search results for: PIPE ROOFING
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Experimental investigation of heat transfer enhancement in straight and U-bend double-pipe heat exchanger with wire insert
PublicationIn this paper, the possibility of heat transfer enhancement in the U-bend exchanger was presented. Experimental research has been carried out for four individual heat exchanger constructions i.e. plain tube in tube, turbulized tube in tube, plain U-bend and U-bend with turbulator. Also, heat transfer experiments for various boundary conditions were performed to obtain reference values. In case of U-bend exchanger with and without...
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Numerical analysis of pile installation effects in cohesive soils
PublicationIn this thesis the empirical equation for radial effective stress calculation after displacement pile installation and following consolidation phase has been proposed. The equation is based on the numerical studies performed with Updated Lagrangian, Arbitrary Lagrangian-Eulerian and Coupled Eulerian-Lagrangian formulations as well as the calibration procedure with database containing world-wide 30 pile static loading tests in cohesive...
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The mechanism of grouting action under the base of bored pile
PublicationThe grouting under the base of bored pile is carried out in order to reduce pile settlement and improve its bearing capacity. The principal aim of grouting is to introduce an initial force between the soil and the pile base. In non-cohesive soil, the grouting can also enlarge the pile base area and therefore improve the base resistance. The example of static load tests on instrumented bored piles installed with and without grouting...
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Criteria for assessment of pine wood surfaces after planing
PublicationThe arise of defects in raw material as well as a machined part in most cases causes need to qualify the final product (wooden frames) as a scrap part or an additional work activity must be done. In the paper selected results of the effect of the material defects on the surface quality of the elements after planing and painting are presented. The materials under production were glulam elements of pine wood. Research experiments...
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Pile Model Tests Using Strain Gauge Technology
PublicationOrdinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine...
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Effect of preconsolidation on pile bearing capacity in model tests
PublicationBadanie wpływu prekonsolidacji gruntu w badaniach modelowych w komorze kalibracyjnej. Zagęszczone piaski kwarcowe poddano prekonsolidacji przy OCR nie większym od 7. Analiza współczynnika parcia spoczynkowego gruntu. Wpływ wskaźnika prekonsolidacji na nośność podstawy i pobocznicy pali oraz zmiany naprężeń wokół modelu i odkształcenia objętościowe masywu gruntowego.
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FEM modelling of screw displacement pile interaction with subsoil
PublicationPredicting the-settlement characteristics of piles is an important element in the designing of pile foundations. The most reliable method in evaluating pile-soil interaction is the static load test, preferably performed with instrumentation for measuring shaft and pile base resistances. This, however, is a mostly post-implementation test. In the design phase, prediction methods are needed, in which numerical simulations play an...
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Estimation of pile bearing capacity by dynamic and static tests
PublicationBadania dynamiczne, szczególnie dla pali wbijanych, w budownictwie hydrotechnicznym stają się coraz bardziej popularne. Badania, poparte formalnie zapisami zawartymi w Eurokodzie 7, wykorzystywane w badaniach ''na wodzie'' i ''na lądzie'' są szybkie i ekonomiczne. Przedstawiono serię badań dla gruntów uwarstwionych dla pali prefabrykowanych żelbetowych, wbijanych stalowych pali rurowych oraz pali Vibro-Fundex. Badania dynamiczne...
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Reservoir Influence on Pressure Wave Propagation in Steel Pipes
PublicationThe relation between the length of steel pipe and the pressure wave period in the system, reservoir-pipe-valve, is discussed. Experiments carried out for the short steel pipes showed that in such a system, the pressure wave celerity estimated using the measured wave cycles systematically increases with the increase of the pipe length. The observed differences can exceed even 90 m=s. As the pressure wave traveling in the pipe with...
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Recent Advances in Loop Heat Pipes with Flat Evaporator
PublicationThe focus of this review is to present the current advances in Loop Heat Pipes (LHP) with flat evaporators, which address the current challenges to the wide implementation of the technology. A recent advance in LHP is the design of flat-shaped evaporators, which is better suited to the geometry of discretely mounted electronics components (microprocessors) and therefore negate the need for an additional transfer surface (saddle)...
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Analyses of Shear Angle in Orthogonal Cutting of Pine Wood
PublicationThe determination of energy effects for wood machining processes, such as cutting power and cutting forces, is very useful in designing of manufacture process of wooden products. A more accurate prediction of cutting forces requires a correct determination of the shear angle value, which can be determined using various models. In this article, shear angle values for an orthogonal linear cutting process of pine wood are determined. The...
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Comparison of sound of organ pipes in contemporary and historical instruments
PublicationThe aim of this research is to examine the differences in the timbre of organ pipes’ sound between a historical and a contemporary organ instrument. The historical instrument is the Oliwa organ from Gdansk, Poland, and the contemporary one is from Kartuzy, Poland. Recordings are made of single notes played by an open labial pipe that belongs to the Principal rank. The analyses and comparison of several sound features compatible...
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Micropropagation, rooting, and acclimatization of two cultivars of goji (Lycium chinense)
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Assessment of the devulcanization process of EPDM waste from roofing systems by combined thermomechanical/microwave procedures
PublicationEthylene-propylene-diene rubber (EPDM) is a elastomer widely used in common industrial applications. EPDM can be shaped into sheets and employed as isolating material for roofing systems. In this study, scraps of EPDM from commercial, industrial and residential roofing systems were treated by combined thermo-mechanical and microwave devulcanization processes including peroxide of benzoyl (BPO). The devulcanized EPDM (Dev-EPDM)...
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Experimental and comparative study on the two-phase pressure drop of air-water mixture in U-bend and straight pipe annuli
PublicationIn this paper, the experimental and theoretical analysis of pressure drop in singlephase and two phase-flow were presented for straight and U-bend smooth tube annulus and tube annulus with wire coil insert. Experiments for various boundary conditions were performed. In case of U-tube and straight tube with and without turbulator, tests were made for the water-water and air-water systems. The study covered a wide measuring range,...
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The Influence of Loop Heat Pipe Evaporator Porous Structure Parameters and Charge on Its Effectiveness for Ethanol and Water as Working Fluids
PublicationAbstract: This paper presents the results of experiments carried out on a specially designed experimental rig designed for the study of capillary pressure generated in the Loop Heat Pipe (LHP) evaporator. The commercially available porous structure made of sintered stainless steel constitutes the wick. Three different geometries of the porous wicks were tested, featuring the pore radius of 1, 3 and 7 um. Ethanol and water as two...
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Final report on noise and rolling resistance
PublicationWork Package 6 deals with environmental impacts of PERS use, including noise and rolling resistance. This report covers preliminary noise tests performed in the laboratory and at the road test sites. The obtained results indicate that PERS material reduce noise considerably - up to 12 dB in comparison to SMA16 reference surface. Noise reduction properties are especially visible in the case of factory produced PERS slabs supplied...
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Rolling resistance measurements of studded tires
PublicationW pracy przedstawiono wyniki pomiaru oporu toczenia opon kolcowanych i po usunięciu kolców na nawierzchni poroelastycznej. Badania przeprowadzono na stanowisku bębnowym Katedry Pojazdów i Maszyn Roboczych Politechniki Gdańskiej. Opony kolcowane mają o około 5% wyższy współczynnik oporu toczenia w porównaniu z oponami nie kolcowanymi.
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Clonal selection algorithm for vehicle routing
PublicationOver the years several successful computing techniques have been inspired by biological mechanisms. Studies of the mechanisms that allow the immune systems of vertebratesto adapt and learn have resulted in a class of algorithms called artificial immune systems. Clonal selection is a process that allows lymphocytes to launch a quick response to known pathogens and to adapt to new, previously unencountered ones. This paper presents...
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The new concept of product. Cooling band
PublicationThe chapter below presents the innovative solution consist in applying the cooling band to help holding the hot object. The solution was found through substitute inputs analysis and brain storm method. The new product was submitted in Polish Patent Office under the No. W.120905.
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A Novel Reliable Routing Scheme for VANETs
PublicationSieci bezprzewodowej transmisji informacji bazujące na rodzinie standardów 802.11, zastosowane w przypadku komunikacji między pojazdami (VANET), mogą istotnie przyczynić się do poprawy bezpieczeństwa ruchu drogowego. Z uwagi na wysoki stopień mobilności pojazdów, dobór tras w sieciach VANET jest problemem trudnym, zwłaszcza w przypadku transmisji wieloskokowej. Rozwiązania dostępne w literaturze ukierunkowane na poprawę dostępności...
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Through the looking-glass of the grazing bifurcation
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Type of surface and tire rolling resistance
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Methods of Tire Rolling Resistance Measurements
PublicationTire rolling resistance is one of the factors related to tire/road interaction that has important influence on road vehicles performance. Raising fuel price and increased concern related to the environmental changes result in growing interest in reduction of tire rolling resistance that influences fuel consumption, especially in free-flowing highway traffic with moderate speeds. There are several methods of tire rolling resistance measurements....
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Device for spoofing in global positioning system
PublicationThis article describes the device which may be used to generate false GPS signals and emit them into radio communication channel. Such attack is called GPS spoofing. Each GPS receiver which remains in the range of a spoofing device (called spoofer) indicates time and position coordinates which are predetermined by the spoofer’s operator. Spoofing may be used e.g. in order to disable the terrorist group from obtaining correct navigation...
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INFLUENCE OF TEMPERATURE ON THE TYRE ROLLING RESISTANCE
PublicationTemperature is a very important factor controlling rolling resistance of road vehicle tyres. There are at least three different temperatures that may be considered as important factors controlling thermal conditions of the rolling tyre. The most common measure of the thermal conditions during tyre rolling is ambient air temperature. The other two are: pavement temperature and “tyre” temperature. Tyre temperature is the most difficult...
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THE APPLICATION OF PHENOMENOLOGICAL METHODOLOGY FOR DESIGNING PILE FOUNDATION IN PORT STRUCTURES
PublicationIt is of utmost importance in the design process that a suitable, safe and concurrently economic solution be chosen. Issues connected with foundations require adopting a special approach. Soil is a composite medium, and it is essential to describe as precisely as possible the interaction taking place between the subgrade and the structure. There are many design methods of pile foundation that are based on in-situ test of soils....
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Report of Eurocode 7 application for pile foundation design in Poland
PublicationThe EC7 rules of geotechnical design are in use in Poland for several years, even though there is no National annex. With regard to pile foundations, there are valid EC7 recommendations concerning design approaches, load partial coefficients, correlation coefficients and capacity partial coefficients. Polish designers can be quite flexible when it comes to choose a method for static, bearing capacity and settlement calculations....
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Numerical study of turbulent flow and heat transfer of nanofluids in pipes
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (6 000 < Re < 12 000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data of Vajjha et al. [1]. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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The Impact of Drying Conditions on the Surface Color Changes of Pine Wood
PublicationThe article presents the impact of drying process and selected parameters on the color changes on the surface of pine wood (Pinus sylvestris L.). Three predetermined process conditions (modes), mild, normal, and intensive, were investigated. The experiments were conducted using a semi-industrial scale dryer designed at the Gdańsk University of Technology with a loading capacity of 0.55 m3. The drying process was applied to pine...
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Construction of pressure pipelines using the modern CC-GRP pipes
PublicationRury GRP mające szczególnie duży zakres średnic powszechnie akceptuje się do przepływów grawitacyjnych. Przedstawiono międzynarodowe doświadczenia ich zastosowania do przepływów ciśnieniowych w wodociągach i kanalizacji. Szczególne doświadczenia w zakresie zastosowania w robotach przy technologiach bezwykopowych.
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Carbon catalysts from pine cones – Synthesis and testing of their activities
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The analysis of soil resistance during screw displacement pile installation
PublicationThe analysis of soil resistances during screw displacement pile installation based on model and field tests. The investigations were carried out as a part of research project, financed by the Polish Ministry of Science and Higher Education. A proposal of empirical method for prediction of rotation resistance (torque) during screw auger penetration in non-cohesive subsoil based on CPT result.
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Large deformation finite element analysis of undrained pile installation
PublicationIn this paper, a numerical undrained analysis of pile jacking into the subsoil using Abaqus software suit has been presented. Two different approaches, including traditional Finite Element Method (FEM) and Arbitrary Lagrangian–Eulerian (ALE) formulation, were tested. In the first method, the soil was modelled as a two-phase medium and effective stress analysis was performed. In the second one (ALE), a single-phase medium was assumed...
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Numerical Study of Turbulent Flow and Heat Transfer of Nanofluids in Pipes
PublicationIn this work, Nusselt number and friction factor are calculated numerically for turbulent pipe flow (Reynolds number between 6000 and 12000) with constant heat flux boundary condition using nanofluids. The nanofluid is modelled with the single-phase approach and the simulation results are compared with experimental data. Ethylene glycol and water, 60:40 EG/W mass ratio, as base fluid and SiO2 nanoparticles are used as nanofluid...
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Static load test on concrete pile – instrumentation and results interpretation
PublicationFor some time (since 8-10 years in Poland) a special static load tests on instrumented piles are carried out. Such studies are usually of a scientific nature and provide detailed quantitative data on the load transfer into the ground and characteristics of particular soil layers interaction with a pile shaft and pile base. Deep knowledge about the pile-subsoil interaction can be applied for a various design purposes, e.g. numerical...
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Application of the Barkhausen effect probe with adjustable m agnetic field direction for stress state determination in the P91 ste el pipe
PublicationThe paper presents the results of application of a novel Barkhausen effect (BE) probe with adjustable magnetizing field direction for the stress level evaluation in ferromagnetic materials. The investigated sample was in a form of a pipe, made of P91 steel that was anisotropic due to the production process. The measurements were performed before and after welding, revealing the influence of welding process on the residual stress...
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Static Load Test on Instrumented Pile – Field Data and Numerical Simulations
PublicationFor some time (since 8-10 years in Poland) a special static load tests on instrumented piles are carried out. Such studies are usually of a scientific nature and provide detailed quantitative data on the load transfer into the ground and characteristics of particular soil layers interaction with a pile shaft and pile base. Deep knowledge about the pile-subsoil interaction can be applied for a various design purposes, e.g. numerical...
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Surface texture of pine wood beams after planing in industrial conditions
PublicationMeasuring the surface features of wooden components after planing is connected with the rising demands regarding to the quality of the painted window frames. In the paper the complex surface texture analysis especially identifying of surface damages using non-contact 3D measurement techniques for precise area measurement were presented.This enabled the study of irregular surface features with sufficient fidelity and resolution....
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Effect of pine essential oil and rotating magnetic field on antimicrobial performance
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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The effect of thermal modification on the quality of the milled surface of beech and pine wood
PublicationThe article deals with the effect of thermal modification on the quality of the created surface during milling on CNC milling cutters. The quality of the created surface is evaluated based on surface roughness, specifically its roughness parameter Ra. The observed surface is created by a shank cutter with a diameter of 20 mm and three cutting edges in a spiral at a standard speed of 18,000. min-1. The article compares thermally...
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Determination of the bearing capacity of pile foundations based on CPT test results
PublicationAnalityczne określanie pełnej krzywej obciążenie - osiadanie na podstawie parametrów geotechnicznych wciąż stanowi bardzo trudne zadanie naukowe i inżynierskie. W pracy przedstawiono metodę bezpośredniego wykorzystania oporów na stożku sondy statycznej do określania pełnej krzywej osiadania dla pali Vibro-Fundex. W sumie jako materiał weryfikacyjny wykorzystano 94 próbne obciążenia statyczne pali.
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Numerical simulation of screw displacement pile interaction with non-cohesive soil
PublicationA trial numerical simulation of screw displacement pile interaction with non-cohesive subsoil during the transfer of compression load. The simulation was carried out in an axisymmetric system. The technological phases of pile installation in the ground were numerically modelled using equivalent processes which provided similar effects to real technical actions. The results of the numerical calculations were verified by comparing...
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EVALUATION OF CAUSES OF CORROSION OF HEATING PIPES AND BALLAST CHAMBERS ON HLVJ INNOVATION
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Probabilistic analysis of settlements under a pile foundation of a road bridge pylon
PublicationThe paper addresses the reliability change of a road bridge pile foundation due to the unpredictable increase of settlements in time. The analysis is based on the Rędziński Bridge in Wrocław, Poland, its design assumptions, and monitoring results. The bridge foundation rests on a multi-layered subsoil assumed random. The Finite Element model of the subgrade is generated in ZSoil® software. To simplify the probabilistic approach,...
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Structural optimization of microjet array cooling system
PublicationThe single phase heat transfer from an upward facing, horizontal copper surface to arrays of impinging water jets was experimentally investigated. Experimental configuration allows for a free-surface unconfined jets flow. Square nozzles 50 × 100 μm arranged in four different geometries were used. Additionally, for the set of two jets array geometry was varied by adjusting the nozzle to nozzle distance. The area averaged heat transfer...
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Development trends of automotive engine cooling systems
PublicationDzięki daleko idącym modyfikacjom układów zasilania i zapłonu silników samochodowych oraz udoskonaleniom układów oczyszczania spalin uzyskano znaczne zmniejszenie emisji związków toksycznych. Układy chłodzenia z pompą cieczy napędzaną mechanicznie stają się archaiczne nie pozwalając na swobodne sterowanie obiegiem cieczy. Również różna wartość temperatury potrzebnej do schładzania różnych procesów wymaga sterowanych zaworów trójdrożnych...
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Multi-objective weather routing of sailing vessels
PublicationThe paper presents a multi-objective deterministic method of weather routing for sailing vessels. Depending on a particular purpose of sailboat weather routing, the presented method makes it possible to customize the criteria and constraints so as to fit a particular user’s needs. Apart from a typical shortest time criterion, safety and comfort can also be taken into account. Additionally, the method supports dynamic weather data:...
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METHOD OF ROUTING SHIPS SAILING IN DEDICATED ENVIRONMENT
PublicationThe method for determining the suboptimal route of sailing vessels operating in a restricted area of the sea are proposed in the paper. The dynamics of the environment including weather conditions and speed characteristics of ships sailing are considered. As optimiza-tion criterion, measure sailing time T, and the number of maneuvers performed ω, are taken into account. An heuristic algorithm, and the appropriate application routing...