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Wyniki wyszukiwania dla: VOLUMETRIC EFFICIENCY
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Influence of the position of the swash plate rotation axis on the volumetric efficiency of the axial pistons pumps
PublikacjaThe article describes the influence of the position of the swash plate axis of rotation on the size of the dead space and the volumetric efficiency of the axial pistons pump. Superposition of the two motions have been proposed - the rotation of the swash plate with respect to axis intersecting the axis of rotation of the pump shaft and the shifts of swash plate yielding a result of the rotation axis offset effect. In the article...
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Influence of Fluid Compressibility and Movements of the Swash Plate Axis of Rotation on the Volumetric Efficiency of Axial Piston Pumps
PublikacjaThis paper describes the design of a swash plate axial piston pump and the theoretical models describing the bulk modulus of aerated and non-aerated fluids. The dead space volume is defined and the influence of this volume and the fluid compressibility on the volumetric efficiency of the pump is considered. A displacement of the swash plate rotation axis is proposed to reduce the dead space volume for small swash plate swing angles....
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Volumetric and torque efficiency of pumps during start-up in low ambient temperatures
PublikacjaThe volumetric, torque and total efficiency of hydraulic pumps change during start-up in low ambient temperatures, as well as in thermal shock conditions, un-til they reach the set conditions. The time to reach steady-state conditions de-pends on many parameters: ambient temperature, flow rate, fluid temperature, design of hydraulic units. The author carried out tests of hydraulic pumps in the Hydraulics Laboratory of the Faculty...
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Mathematical model defining volumetric losses of hydraulic oil compression in a variable capacity displacement pump
PublikacjaThe objective of the work is to develop the capability of evaluating the volumetric losses of hydraulic oil compression in the working chambers of high pressure variable capacity displacement pump. Volumetric losses of oil compression must be determined as functions of the same parameters, which the volumetric losses due to leakage, resulting from the quality of design solution of the pump, are evaluated as dependent on and also...
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Air-cooled photovoltaic roof tile as an example of the BIPVT system – An experimental study on the energy and exergy performance
PublikacjaThe air-cooled photovoltaic tile is a subject of presented investigations, which focused on improving the overall system efficiency of PV tiles with heat recovery. The operational efficiency of a PV roof tile, together with the construction optimising the air cooling efficiency, were the main points of plans realized at this research stage. The article describes the experimental research consisting of the assessment of electrical,...
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Experimental Research of an Axial Piston Pump with Displaced Swash Plate Axis of Rotation
PublikacjaThe article describes the influence of displacement of the swash plate rotation axis on the efficiency of axial piston pumps. The dead space volume was defined as the volume of the working chamber in the extreme position of the piston at the end of the pumping phase and its variability was determined as a function of the position of the axis of rotation of the swash plate and the swing angle of swash plate. The influence of swash...
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Simultaneous impedance and volumetric studies and additionally potentiodynamic polarization measurements of molasses as a carbon steel corrosion inhibitor in 1M hydrochloric acid solution
PublikacjaThe inhibition effect of molasses on the corrosion of low carbon steel in 1M hydrochloric acid solution was investigated by volumetric and electrochemical measurements. Potentiodynamic polarization and dynamic electrochemical impedance spectroscopy (DEIS) results were obtained and compared with to those, obtained with the hydrogen evolution technique. All results indicate that molasses functioned as a good inhibitor in 1M hydrochloric...
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The Methodology for Determining the Theoretical Based on the Characteristics of Effective Absorbency Versus Pressure Drop in the Motor
PublikacjaThis article describes a method for determining the theoretical and actual working volume of a hydraulic motor. It has been shown that the actual working volume of the motor is the sum of the theoretical working volume and the additional volume that depends on the pressure drop in the working chambers of the motor. It was also shown that the volumetric losses in the hydraulic motor are not only a function of the pressure drop in...
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Assessment of thermal and electrical performance of flat plate air-cooled photovoltaic roof tile – experimental and numerical studies
PublikacjaThe current state of development of the solar energy sector necessitates a new form of incentive for entities to invest in photovoltaic (PV) installations. Building-integrated photovoltaic/thermal (BIPV/T) systems are gaining increasing interest. Effective methods for heat recovery from BIPV/T collectors are searched for. Presented research experimentally and numerically considered the influence of cooling conditions on the electrical...
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Power balance in hydraulic satellite motors supplied with oil and HFA-E emulsion
PublikacjaMineral oil and HFA-E emulsion are liquids which differ in viscosity, density and lubricant properties. Therefore, supplying hydraulic satellite motors with these liquids, differences between quantity of hydraulic, volumetric and mechanical losses are observed. These losses influence efficiency of conversion of hydraulic energy into mechanical energy and thereby power balance of motors.
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Comparative study of a bottoming SRC and ORC for Joule–Brayton cycle cooling modular HTR exergy losses, fluid-flow machinery main dimensions, and partial loads
PublikacjaEnergy conversion efficiency increase in power plants with high-temperature gas-cooled reactors via implementation of the bottoming cycle was investigated under nominal and minimal thermal load of a high-temperature reactor (HTR). Heat transfer surface area and turbine outlet volumetric flow rate in bottoming cycles was also investigated. Water and two low-boiling point working fluids (ammonia and ethanol) were analyzed. Analyzed...
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R&D of satellite pumps and motors with small geometrical displacement supplied with oil and non-flammable liquids
PublikacjaThe newest construction of satellite motors and self-suction satellite pumps with small geometrical displacement have been described in this article. The characteristics of volumetric and total efficiency of one satellite motor, selected from the series, supplied with oil have been presented. These characteristics have been compared with the orbital motors' characteristics. The remaining specifications of these motors were also...
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Losses and power balance in hydraulic satellite motor supplied with oil and HFA-E emulsion
PublikacjaMineral oil and HFA-E emulsion are liquids which differ in viscosity, density and lubricant properties. Therefore, supplying hydraulic satellite motor with these liquids, differences between quantity of hydraulic, volumetric and mechanical losses are observed. These losses influence efficiency of conversion of hydraulic energy into mechanical energy and thereby power balance of motor. The research of satellite motor has been conducted...
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New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
PublikacjaThis paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity...
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Exploring hydrogen energy systems: A comprehensive review of technologies, applications, prevailing trends, and associated challenges
PublikacjaExploring hydrogen energy and its associated technologies is a pivotal pathway towards achieving carbon neutrality. This article comprehensively reviews hydrogen production technologies, storage technologies, and end-use applications of hydrogen, based on the input energy source, operating conditions, conversion efficiency, energy density, and unit investment cost. The review also highlights the advantages, disadvantages, and technological readiness...
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Determination of the Theoretical and Actual Working Volume of a Hydraulic Motor—Part II (The Method Based on the Characteristics of Effective Absorbency of the Motor)
Publikacja: In this article, the second method of determination of the theoretical and actual working volume of a hydraulic motor is described. The proposed new method is based on the characteristics of effective absorbency of the motor. The effective absorbency has been defined as the ratio of flow rate in a motor to the rotational speed of the motor’s shaft. It has been shown that the effective absorbency is a nonlinear function of the...
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Influence of operating pressure on the durability of a satellite hydraulic motor supplied by rapeseed oil
PublikacjaThis article describes the results of a durability test of a hydraulic satellite motor supplied by rapeseed oil. The tests were carried out on a test stand in a power recuperation system. The tests of the motor were carried out at a constant shaft speed for three fixed pressure drops in the motor. This made it possible to demonstrate the influence of the motor operating pressure on the durability of the satellite mechanism. The...
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Instantaneous Impedance Analysis of Non-Stationary Corrosion Process: a Case Study of Carbon Steel in 1M HCl
PublikacjaThe paper concerns the problem of evaluation of stationarity of carbon steel corrosion in 1M HCl. Comparison of corrosion rate with addition of corrosion inhibitor to the reference measurement is the most often used way of evaluating inhibitor efficiency. Such an approach is valid only if corrosion rate is a stationary process. Two complementary techniques were used simultaneously: volumetric analysis of evolved hydrogen and instantaneous...
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Experimental and numerical study of thermal and electrical potential of BIPV/T collector in the form of air-cooled photovoltaic roof tile
PublikacjaAmong renewable energy sources, Building-Integrated Photovoltaic/Thermal (BIPV/T) systems are gaining increasing interest. To improve their economic competitiveness, technologies that increase their efficiency are searched for. The paper is devoted to evaluating the impact of various air-cooling configurations on the thermal and electrical performance of a photovoltaic roof tile. A numerical model of the own experimental system...
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Energy Loss Coefficients ki in a Displacement Pump and Hydraulic Motor used in Hydrostatic Drives
PublikacjaThe article aims at defining and analysing the energy loss coefficients in design solutions of rotating displacement machines, with a piston machine as an example. The energy losses observed in these machines include mechanical loss, volumetric loss, and pressure loss. The scale and relations between these losses in different machines depend on machine design and manufacturing quality, and on operating parameters. The operating...
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Analysis of cyclone separator solutions depending on spray ejector condenser conditions
PublikacjaThe core design strategy for minimizing CO2 emissions in gas power plant entails combining a spray ejector condenser (SEC) and separator to accomplish steam condensation and CO2 purification. This innovative process involves direct-contact condensation of steam with CO2, facilitated by interaction with a subcooled water spray, along with a cyclone separator mechanism intended for generating pure CO2. The investigation of the SEC...
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Evaluation of losses in a hydraulic motor based on the SWSB - 63 motor tests
PublikacjaIn this paper are compared two models of energy losses: that suggested by Prof. Paszota,Z. in monograph "Energy losses in the hydraulic displacement motors - definitions and relations serving the evaluation of the efficiency of hydrostatic drive" [18] and that ofProf. Balawender, A. in "Energy analysis and methodology of testing of low-speed hydraulic motors" [1]. By using the data obtained from the tests of SWSB-63 hydraulic motors...
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The influence of pressure drop on the working volume of a hydraulic motor
PublikacjaReliability and maintenance analysis of hydraulic positive machines basicly focused on the processes of their wear and failure. But in order to correctly assess the mechanical and volumetric efficiency of a hydraulic motor, both at the stage of development research or at the stage of control tests during its exploitation, the working volume of this motor must be correctly determined. Therefore this paper proposes a new method of...
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Influence of Gaps’ Geometry Change on Leakage Flow in Axial Piston Pumps
PublikacjaAxial piston pumps are the core elements of most medium and high-pressure hydraulic systems. High volumetric efficiency and high working pressures are the main advantages of this type of pumps. Therefore it is necessary to accurately calculate the leakage flow through the gaps to design efficient high-pressure pump. The main difficulty of such calculations is the fact, that the gaps change their geometry during pumping process....
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Influence of the low ambient temperature on the start-up process of hydraulic pumps
PublikacjaStarting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of pressure drop in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump working chambers with...
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Acclimation of denitrifying activated sludge to a single vs. complex external carbon source during a start-up of sequencing batch reactors treating ammonium-rich anaerobic sludge digester liquors
PublikacjaIn this study, denitrification of ammonium- reach anaerobic sludge digester liquor was investigated during start-up periods of two laboratory- scale ‘‘fill-and-draw’’ reactors. One reactor was fed with a single carbon source (ethanol), whereas the other reactor was fed with a complex carbon source (fusel oil). During two acclimation experiments, the structure of microbial community involved in denitrification was analyzed using...
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Window frame integrable air recuperation minichannel/minigap heat exchanger
PublikacjaThis article describes an evaluation of mini heat exchangers operation as a decentralized mechanical ventilation system with recuperative heat recovery that can be integrated into the window frame. The relatively small yet efficient air recuperation system allows for retrofitting existing buildings by reducing the overall energy consumption and thus the CO2 emissions. The proposed design, unlike existing systems, is easy to scale...
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Metodyka badań rozwojowych nowego typu silników i pomp satelitowych
PublikacjaResearch and development of new type satellite motors and satellite pumps SM with small geometrical displacement, from 5 to 73 cm3/rev, has been conducted in cooperation with Stosowanie Maszyn company from Katowice (manufacturer of motors and pump SM). The improvement of construction of those machines, especially construction of axial compensation and construction of fluid distribution channels have been the main problem of research...
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The influence of water and mineral oil on volumetric losses in the displacement pump for offshore and marine applications
PublikacjaIn this paper volumetric losses in a positive displacement pump supplied with water and mineral oil are described and compared. The experimental tests were conducted using a prototype of a satellite pump (with a non-circular tooth working mechanism). In this paper the sources of volumetric losses in this pump are characterised. On this basis, a mathematical model of these losses has been presented. The results of the calculation...
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RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
PublikacjaStarting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of increase of resistance of cold oil flow in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump...
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The influence of water and mineral oil on volumetric losses in a hydraulic motor
PublikacjaIn this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and comparison. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquid, including water. The sources of leaks in this motor are characterized and described also. On this...
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Comparison of the powers of energy losses in a variable capacity displacement pump determined without or with taking into account the power of hydraulic oil compression
PublikacjaPowers of energy losses in a variable capacity displacement pump are compared with or without taking into account the power of hydraulic oil compression. Evaluation of power of liquid compression in the pump was made possible by the use of method, proposed by the Author, of determining the degree of liquid aeration in the pump. In the method of determining the liquid aeration in the pump and of powers of volumetric losses of liquid...
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Kazimierz Darowicki prof. dr hab. inż.
OsobyStudia wyższe ukończyłem w czerwcu 1981 roku po zdaniu egzaminu dyplomowego i obronie pracy magisterskiej. Opiekunem pracy magisterskiej był dr hab. inż. Tadeusz Szauer. W roku 1991, 27 listopada uzyskałem stopień naukowy broniąc pracę doktorską zatytułowaną „Symulacyjna i korelacyjna analiza widm immitancyjnych inhibitowanej reakcji elektrodowej”. Promotorem pracy był prof. dr hab. inż. Józef Kubicki (Wydział Chemiczny...
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Understanding the interactions between protein stabilizers and the peptide bond through the analysis of the volumetric and compressibility properties for the model systems
PublikacjaThis work confirms our earlier supposition, that volumetric and acoustic parameters for simple model proposed by us are directly related to stabilizing/destabilizing effect of osmolytes on proteins structure. The apparent molar volumes, V and the apparent molar isentropic compressions, KS,, of glycine and N,N,N –trimethylglycine (betaine) were determined from densities and speed of sound measurements in aqueous solution of N-methylacetamide...
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Mass transfer in Spinning Fluids Reactor — Measurement and prediction
PublikacjaSpecific mass transfer area (a) and overall volumetric mass transfer coefficient (kLa) are mass transfer parameters commonly used in the description and comparison of various chemical reactors’ constructions. Determination of these was performed for Spinning Fluids Reactor (SFR). Sodium sulfite oxidation in the presence of cobalt ion catalyst was used for the determination of a and kLa. The a and kLa were successful predicted....
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Effect of Linear Energy and Microstructure on the Content of Residual Hydrogen in Welded Joints made of Superduplex Steels
PublikacjaThe article presents tests concerning the content of retained hydrogen present in FCAW and SAW welded joints made of superduplex steel. The use of various welding technologies resulted in the obtainment of welds having different microstructures and ferrite contents. Measurements of retained hydrogen present in joints (performed using the complete combustion method) revealed various contents of hydrogen in the base material and...
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Solvation phenomena in ternary system tetramethylurea-methylacetamide-water: Insights from volumetric, compressibility and FTIR analysis
PublikacjaThe properties of the ternary systems N,N,N’,N’-tetramethylurea - N-methylacetamide - water were investigated using Fourier-transform infrared spectroscopy (FTIR), volumetric and compression measurements. Densities and sound velocities were determined in order to obtain the apparent molar volumes (VΦ) and apparent molar isentropic compressions (ΚS,Φ). These values were then extrapolated to infinite dilution. Additionally, interaction parameters...
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Brewery spent grain valorization through fermentation: Targeting biohydrogen, carboxylic acids and methane production
PublikacjaThis study investigated three different fermentation approaches to explore the potential for producing biohydrogen, carboxylic acids, and methane from hydrolysates of thermally dilute acid pretreated brewer's spent grains (BSG). Initially, the research focused on maximizing the volumetric hydrogen production rate (HPR) in the continuous dark fermentation (DF) of BSG hydrolysates by varying the hydraulic retention time (HRT). The...
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Monitoring of lysozyme thermal denaturation by volumetric measurements and nanoDSF technique in the presence of N-butylurea
PublikacjaThe results of thermal studies of denaturation of hen egg white lysozyme (HEWL) in water and an aqueous solution of N-butylurea (BU) are presented. High-precision densimetric measurements were used to characterize and analyze the changes of the specific volume, v, during temperature elevation. The temperature of the midpoint of protein denaturation was also determined by nanoDSF technique (differential scanning fluorimetry). The...
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Mechanical characterization of a gravel column in a calibration chamber operating as a triaxial cell
PublikacjaA series of tests considering the behavior of gravel columns was performed. A segment of column with a height of 1 m and a diameter of 0.53 m was modelled in a calibration chamber used as a triaxial cell at three different lateral stress applied. The vertical load transferred on the column head was simulated with steady increase of water pressures in the upper and lower membranes. During the loading the volumetric changes in the...
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Discussion of “Development of an Accurate Time integration Technique for the Assessment of Q-Based versus h-Based Formulations of the Diffusion Wave Equation for Flow Routing” by K. Hasanvand, M.R. Hashemi and M.J. Abedini
PublikacjaThe discusser read the original with great interest. It seems, however, that some aspects of the original paper need additional comments. The authors of the original paper discuss the accuracy of a numerical solution of the diffusion wave equation formulated with respect to different state variables. The analysis focuses on nonlinear equations in the form of a single transport equation with the discharge Q (volumetric flow rate)...
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New data acquisition system for birch sap concentrate production using the reverse osmosis technology
PublikacjaThe work presents a simple electronic device that helps to monitor the basic parameters of the reverse osmosis (RO) system during the concentration of birch tree sap. The construction costs are low (around 150 Euro) but the functionality of the device is high. It has an in-build two channel conductometer and can measure the volumetric flow rate of two streams of liquids. The collected data are transmitted wirelessly via Bluetooth...
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Structural properties of hypothetical CeBa2Cu3O7 compound from LSDA+DMFT calculations
PublikacjaThe hypothetical stoichiometric CeBa2Cu3O7 (Ce123) compound, which has not been synthesized as a single phase yet, was studied by the density functional theory (DFT). We utilized a method which merges the local spin density approximation (LSDA) with the dynamical mean-field theory (DMFT) to account for the electronic correlations. The LSDA+DMFT calculations were performed in the high-temperature range. The particular emphasis was...
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Enhanced energy conversion as a result of fluid-solid interaction in micro- and nanoscale
PublikacjaIt is known that nano- and micromechanics require new approaches to right describing of surface-like phenomena which lead to an enhanced energy conversion. In this work, a general form of surface forces that consist of a contribution from both the friction and mobility components has been extended to collect the effects of bulk and surface motion of a fluid. Quite similar impact can be observed for a solid-fluid mixture, where...
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The Impact Of The Selected Parameters Of Fdm Manufacturing Technology On Tribological Performance Of Abs–Steel Pair Under Dry Friction
PublikacjaThe paper presents the result of tribological test of ABS and steel samples sliding under dry friction. Polymeric samples were manufactured of ABS material using FDM technology. Testing was carried out in unidirectional sliding in a ring-on-flat contact in a PT-3 tribometer. The scope of tested parameters included volumetric and mass wear, the friction coefficient, and polymeric specimen temperature. Polymeric specimens used in...
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A variational approach of homogenization of piezoelectric composites towards piezoelectric and flexoelectric effective media
PublikacjaThe effective piezoelectric properties of heterogeneous materials are evaluated in the context of periodic homogenization, whereby a variational formulation is developed, articulated with the extended Hill macrohomogeneity condition. The entire set of homogenized piezoelectric moduli is obtained as the volumetric averages of the microscopic properties of the individual constituents weighted by the displacement and polarization...
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Effect of oxygenation time on signal of a sensor based on ionic liquids
PublikacjaThe paper presents an oxygen sensor based on ionic liquids and solid electrodes. The following ionic liquids have been employed: [BMIM][BF4], [HMIM][Cl], [BMIM][N(CN2)]. Minimum time of the sensor exposure to analyte, after which the signal (current intensity) was stable, has been evaluated. An impact of volumetric flow rate of analyte on the sensor exposure time and signal has been determined. A product of permeability coefficient...
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The hydration of the protein stabilizing agents: trimethylamine-N-oxide, glycine and its N-methylderivatives - the volumetric and compressibility studies
PublikacjaThe densities at T = (288.15, 293.15, 298.15, 303.15, and 308.15) K and sound velocities at T = 298.15 K have been measured for aqueous solutions of trimethylamine-N-oxide, glycine, N-methylglycine (sarcosine), N,N-dimethylglycine, N,N,N-trimethylglycine (betaine). From these data the apparent molar volumes, VΦ, the apparent molar isentropic compressions, KS,Φ, and the solvation numbers of solutes have been determined. The concentration...
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New satellite pumps
PublikacjaStosowanie Maszyn company from Katowice was initiator and originator of newest original high pressure satellite pumps series of types PSM. Construction solution, research and development of these pumps have been conducted by Team of Hydraulics and Pneumatics of Gdansk University of Technology in cooperation with this company within the confines of research project nr R0300103 (source of funds: Ministry of Science and Higher Education)....
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Geotechnical characterization of soft soil deposits in Northern Poland
PublikacjaThis paper presents a geotechnical characterization of deltaic soft soil deposits in the Vistula Marshlands, northern Poland. It shows the limited applicability of organic soil classifications based on Cone Penetration Tests (CPTU) and Dilatometer Tests (DMT). None of the in-situ-based classifications correctly identifies peat. Analysis of the behaviour of contractive/dilative soil layers according to Robertson's updated classification...