Search results for: WORKING CONDITIONS
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Organic Rankine as bottoming cycle to a combined Brayton and Clausius-Rankine cycle
PublicationThis paper presents an enhanced approach, as it will be considered here that the ORC installation could be extra-heated with the bleed steam, a concept presented by the authors. In such way the efficiency of the bottoming cycle can be increased and an amount of electricity generated increases. A thermodynamic analysis and a comparative study of the cycle efficiency for a simplified steam cycle cooperating with ORC cycle will be...
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Dispersive Micro‐Solid Phase Extraction of Selected Metals in Water and Food Samples Followed by ICP‐OES Analysis: Method Development, Analysis of Real Samples and Greenness Evaluation
PublicationMultiwalled carbon nanotubes (MWCNTs) are well-known adsorbents because of their high surface area, layered and hollow architecture, hydrophobicity, and multiple and easily accessible adsorption sites. In this study, MWCNTs were used for dispersive micro-solid-phase extraction of various metal chelates in environmental and food samples. Different parameters such as concentration of the chelating reagent, the sorbent dosage, the...
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HCI-Based Wireless System for Measuring the Concentration of Mining Machinery and Equipment Operators
PublicationMaintaining stable and reliable working conditions is a matter of vital importance for various companies, especially those involving heavy machinery. Due to human exhaustion, as well as unpredicted hazards and dangerous situations, the personnel has to take actions and wisely plan each move. This paper presents a human–computer interaction (HCI)-based system that uses a concentration level measurement function to increase the safety...
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Youth attitude to entrepreneurship in Eastern and Central European countries: Gender aspect
PublicationCurrent business conditions pose new challenges to youth entrepreneurship, which is a significant component of countries’ economic growth. In addition, Generation Z differs from previous generations and requires new approaches. In this context, a comprehensive study of the peculiarities and various aspects of youth entrepreneurship development is highly-demanded and relevant. Furthermore, the lower representation of women among...
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Flow Maps and Flow Patterns of R1233zd(E) in a Circular Minichannel at Low, Medium and High Values of Saturation Pressure
PublicationThere is a gap in knowledge regarding the flow pattern of low-boiling working fluids in the range of high saturation temperatures (above 120°C) and medium and high reduced pressures (0.5-0.9). Data are present in the literature for similar values of reduced pressures, but for lower values of saturation temperature. This is due to the existing refrigeration applications of these working fluids. At high values of reduced pressure,...
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RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
PublicationStarting 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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Dagmara Nikulin dr
PeopleBio: Dagmara Nikulin Dagmara Nikulin has been employed at the Faculty of Management and Economics as a research and teaching assistant professor since 2014. Initially, she worked at the Department of Economic Sciences, and now at the Department of Statistics and Econometrics. She is a graduate of the Faculty of Economics at the Poznań University of Economics (2009) and the Faculty of Social Sciences of the Adam Mickiewicz University...
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The use of Preston equation to determine material removal during lap-grinding with electroplated CBN tools
PublicationGrinding executed in a lapping configuration is an alternative finishing process benefiting from both grinding and free-abrasive machining, while minimizing the heat effect impact. Electroplated tools can be effectively used in different abrasive processes, including high-speed grinding, however, the assessment of machining performance over time is a key factor in their correct use to achieve satisfactory technological results....
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„Eulerian – Eulerian” versus ,,Eulerian –Lagrangean” models of condensation
PublicationLiquid phase in the flowing vapor through stages of the steam turbine is the cause of a lot of failures. Nowadays, due to work of steam turbines at partial load, process of homogeneous and heterogeneous condensation still is current. The formation of drops of condensate under conditions other than nominal operation of turbine is a process still unknown. Engineers and designers involved in the development of power station machines...
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THE APPLICATION OF KALMAN FILTERING TO PREDICT VERTICAL RAIL AXIS DISPLACEMENTS OF THE OVERHEAD CRANE BEING A COMPONENT OF SEAPORT TRANSPORT STRUCTURE
PublicationAs the devices designed to transport materials, the overhead cranes should meet certain geometric requirements for their operation to be safe. The presently available geodetic equipment, in particular total stations, provides opportunities for precise 3D measurements of coordinates of the controlled points. These coordinates make a basis for correcting the height of crane runway axes. The paper presents a method to calculate position...
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An approach for estimation of water wall degradation within pulverized-coal boilers
PublicationThe main aim of this paper is to estimate the lifetime of water walls of pulverized-coal boilers at nominal conditions as well as after degradation of water tubes. An approach for a pulverized-coal chamber degradation process has been formulated based on operational and experimental data. This model was formulated using on-line state monitoring of a pulverized coal burner with aim of preventing the fireplace screens from high degradation...
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Influence of process of straightening ship hull structure made of 316L stainless steel on corrosion resistance and mechanical properties
PublicationThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries, for architectural elements, and many others. The chemical composition of corrosion-resistant...
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Evaluation of Medical Staff Satisfaction for Workplace Architecture in Temporary COVID-19 Hospital: A Case Study in Gdańsk, Poland
PublicationThis article analyses the architecture that was used in the temporary AmberExpo hospital in Gdańsk, Poland which was installed during the COVID-19 pandemic. The construction of this type of facility is often based on experimental approaches, aimed at caring for patients suffering from an infectious disease in emergency conditions. In order to assess the level of employee satisfaction with the architectural and technical elements...
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Studies of the Modelling Accuracy of Steam Turbine Control Systems for Diagnostic Tests of Automatic Synchronizers
PublicationOne of the important factors that affect the reliable operation of the power system and the rapid restitution after disaster is a quick and effective combining synchronous electric power facilities to operate in parallel. Hence, diagnostics of automatic synchronizers at every stage of their life, from building a prototype, through the whole life, until removing such devices from the operation, is an extremely important and responsible...
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Hydrogenation process ofTiO2/BiVO4/PEDOT:PSS observed by XPS method
Open Research DataTitania nanotubes synthesis was based on a two-stage anodization process at water/ethylene glycol (5%/95%) electrolyte containing 0.27 M NH4F and 1 M H3PO4 described previously. Anodization process was performed in two-electrode cell compartment using platinum mesh as a cathode. The distance between electrodes was about 2 cm. The anodization voltage...
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Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
PublicationGraphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet....
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Thermal-Hydraulic Studies on the Shell-and-Tube Heat Exchanger with Minijets
PublicationIn this paper a patented design of a heat exchanger with minijets, with a cylindrical construction is presented. It is followed by the results of its systematic experimental investigations in the single-phase convection heat transfer mode. Based on these results, validation of selected correlations (coming from the literature) describing the Nusselt number was carried out. An assessment of the heat exchange intensification level...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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EVALUATING THE INFLUENCE OF BENDING STRESS ON A 1H18N9 STEEL SHAFT WEAR PROCESS IN A WATER LUBRICATED SLIDING BEARING WITH A RUBBER BUSHING
PublicationThe issue of excessive wear of shaft journals co-working with a rubber bearing has been unexplained so far. Premature and sometimes very intensive wear of ship sliding bearings in water conditions is the reason for carry out very expensive and more frequent than expected repairs. The authors (E. Piątkowska, W. Litwin) made an attempt to find a case that influences the value of this wear described in the paper “Attempt at Evaluating...
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A survey on network resiliency methodologies against weather-based disruptions
PublicationDue to the increasing dependence on network services of our society, research has recently been concentrating on enhancing traditional protection strategies to withstand large-scale failures, as in case of disaster events. The recently-formed EU-funded RECODIS project aims at coordinating and fostering research collaboration in Europe on disaster resiliency in communication networks. In particular, the Working Group (WG) 2 of the...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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Response of a New Low-Coherence Fabry-Perot Sensor to Hematocrit Levels in Human Blood
PublicationIn this paper, a low-coherence Fabry-Perot sensor with a spectrally measured signal processing response to the refractive index of liquids is presented. Optical fiber sensors are potentially capable of continuous measuring hematocrit levels in blood. Low-coherence Fabry-Perot interferometric sensors offer a robust solution, where information about the measurand is encoded in the full spectrum of light reflected from the sensing...
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E-Technologies in Teaching Research Methodology for Engineers – a Case Study of the Course for International Postgraduate Students
PublicationThe Research Methodology course for postgraduate students is challenging, even for an experienced academic teacher. The primary objective of this course is to prepare participants to conduct scientific research and publish the results. This case study presents an original teaching method applied to Research Methodology with Emphasis on Engineering Science, for international engineering students at...
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Non-Adaptive Rotor Speed Estimation of Induction Machine in an Adaptive Full-Order Observer
PublicationIn the sensorless control system of an induction machine, the rotor speed value is not measured but reconstructed by an observer structure. The rotor speed value can be reconstructed by the classical adaptive law with the integrator. The second approach, which is the main contribution of this paper, is the non-adaptive structure without an integrator. The proposed method of the rotor speed reconstruction is based on an algebraic...
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Influence of bush wear in water lubricated marine stern tube bearings with shaft misalignment
PublicationWater lubricated propeller shaft bearings are frequently employed on modern ships due to their advantages such as durability, simplicity and low price. Specific working conditions on ships cause shaft misalignment which often results in rapid wearing of bush and shaft. Shaft misalignment could be an effect of manufacturing or assembly faults but sometimes it appears due to hull or shaft deformation. The wearing process has influence...
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Current trends in analytical strategies for the determination of polybrominated diphenyl ethers (PBDEs) in samples with different matrix compositions – Part 2: New approaches to PBDEs determination
PublicationHerein, we review the latest technical solutions for polybrominated diphenyl ethers (PBDEs) determination in samples with different matrix compositions, largely focusing on gas chromatography but also presenting some liquid chromatography–based solutions. Moreover, we discuss the use of diverse sample injection techniques while considering the advantages and disadvantages of each injection system in the context of PBDEs analysis....
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Selection of C-Type Filters for Reactive Power Compensation and Filtration of Higher Harmonics Injected into the Transmission System by Arc Furnaces
PublicationThis article presents a method for selecting the elements of a C-type filter working with a conventional LC-type filter for compensating reactive power and filtering out higher harmonics generated by arc furnaces and ladle furnaces. The study was conducted in a steel mill supplied by a 110 kV transmission system, where higher harmonic currents and nonlinear loads were measured. A series of computer simulations were performed under...
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Nitrogen fraction fluctuation during wastewater treatment in a multistage treatment wetland
PublicationAlthough the size of pollutants discharged to a WWTP plays an important and often underestimated role in characterizing treat ability and hence the degree of contaminant removal of wastewater. From one hend In order to obtain efficient nitrogen removal in thedenitrification process, sufficient amounts of bioavailable carbon source should be ensured bur for the other hand in TWs, particulates from the wastewater are naturally trapped...
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Pressure drop related to flow maldistribution in a model minichannel plate heat exchanger
PublicationThe paper describes the issues related to the pressure drop that accompanies the phenomenon of maldistribution of working fluid between the channels of a model minichannel plate heat exchanger. The research concerns a single exchanger's plate containing 51 (in every geometry) parallel rectangular minichannels of hydraulic diameters 461 µm, 571 µm, 750 µm and 823 µm. In addition, the more complex geometry has been investigated,...
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Laser-assisted approach for improved performance of Au-Ti based glucose sensing electrodes
PublicationThis paper focuses on the synthesis route and electrochemical properties of electrocatalytic material based on gold nanoparticles (NPs) embedded in a structured titanium template obtained via optimized anodization, chemical etching and laser processing. SEM inspection reveals the presence of Au NPs (60–90 nm in diameter) sited in the titanium foil cavities. Performed electrochemical measurements enable nomination of the set of working...
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Investigation of the Effect of the Rocket's Suborbital Flight on Biofilm, Enzymes and Biosynthesis on Autonomous, Modular and Scalable Platforms For Conducting Experiments of an Astrobiotechnological Nature
PublicationWith new incentives for human space exploration, biotechnological experiments in orbit became imperative. Answering this need, we build an autonomous, modular, and scalable platform that enables those experiments on rockets. We called it AMBER. The aim of the payload of the R6 suborbital rocket is to perform an experiment to study the influence of rocket flights on biofilm, molecular biology enzymes and biosynthesis using our platform....
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Investigation of the Few‐Layer Black Phosphorus Degradation by the Photonic Measurements
PublicationFew-layer black phosphorus (FLBP) is a 2D material that gains worldwide interest for its possible applications, mainly in electronics and optoelec-tronics. However, as FLBP is prone to a degradation process under envi-ronmental conditions, there is a need for a monitoring method allowing investigation of its surface quality. Among many techniques, optoelectronic ones have unique advantages of fast response, non-contact, and non-invasive...
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Straightening of ship hull structure made of 316L stainless steel - tensile test of water cooled materia
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - tensile test of reference material materia (transverse direction)
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - tensile test of reference material materia (longitudinal direction)
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - microstructure of naturally colled material
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - microstructure of water cooled material
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - microstructure of reference material
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Straightening of ship hull structure made of 316L stainless steel - tensile test of naturally cooled material
Open Research DataThe AISI 316L type steel belongs to the group of chromium-nickel stainless steels. They are determined according to European standards as X2CrNiMo17-12-2 and belong to the group of austenitic stainless steels. Steels of this group are used for elements working in seawater environments, for installations in the chemical, paper, and food, industries,...
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Badania eksperymentalne rezonansowego przetwornika piezoelektrycznego typu "unimorph"
PublicationW artykule opisano badania eksperymentalne piezoelektrycznego rezonansowego przetwornika zastosowanego do pomiaru właściwości mechanicznych tkanek miękkich. Po krótkim wstępie w kolejnych punktach przedstawiono opis stanowiska pomiarowego oraz metody pomiaru odkształceń prototypów, przesunięć częstotliwości rezonansowej, impedancji elektromechanicznej i parametrów schematów zastępczych. W dalszej...
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Energy Yield Generated by a Small Building Integrated Photovoltaic Installation
PublicationIn the recent years photovoltaic (PV) industry has experienced a major growth, caused by the ever present annual decrease in module production prices and the expanding awareness of the general public in terms of renewable energy. There are numerous ways to implement PV modules as an additional energy source for a building, be it mounted on the rooftop, or building integrated (BIPV). An analysis of BIPV consisting of 8 modules with...
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Impact of rotor geometry optimization on the off-design ORC turbine performance
PublicationThe paper describes the method of CFD based Nelder-Mead optimization of a 10 kW single-stage axial turbine operating in an ORC system working on R7100. The total-to-static isentropic efficiency is defined as an objective function. Multi-point linear regression is carried out to determine the significance of the objective function arguments and to pick up the set of particular variables and characteristic quantities (e.g. flow angles)...
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A dissimilar welded joint of grade 92 steel and AISI 304L steel obtained using IN82 buttering and IN617 fller: relationship of microstructure and mechanical properties
PublicationUnfavourable operating conditions of equipment in the energy industry resulting from high-temperature loads determine the need to use special materials and technological solutions, including welding procedures. In this article, buttering using IN82 (ERNiCr-3) consumables was proposed as a method to improve the weldability of grade 92 steel joined by the gas tungsten arc welding (GTAW) process with AISI 304L (IN617 fller). The...
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Karolina Krośnicka dr hab. inż. arch.
PeopleKarolina A. Krośnicka, Ph.D., D.Sc., Eng. Arch., is associated professor at Department of Urban Design and Regional Planning, Faculty of Architecture, Gdańsk University of Technology (Poland). For many years (1998 – 2016) she was employed at the Department of Transport and Logistics at the Faculty of Navigation at Gdynia Maritime University (Gdynia, Poland), where she was mostly involved in issues connected with seaports and port...
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Wizyjny system monitoringu stanu nakładek stykowych odbieraków prądu
PublicationEksploatowane do niedawna w Polsce nakładki pantografów kolejowych były wykonywane w postaci styków miedzianych. Na początku 2011 r. przeprowadzono kompleksową zmianę typu nakładek stykowych, stosowanych przez operatorów korzystających z infrastruktury PKP PLK S.A., z miedzianych na metalizowane węglowe. Wraz z wprowadzeniem nakładek węglowych istnieje potrzeba opracowania nowych metod diagnostyki tego istotnego elementu toru zasilania...
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Technological effect comparison of abrasive and plastic working. Production Processes and Systems**2002 vol. 1 s. 89-98, 9 rys. 2 tabl. bibliogr. 6 poz Publication of the University of Miskolc. Porównanie technologicznych efektów obróbki ściernej i plastycznej.
PublicationPrzedstawiono wyniki badań porównawczych próbek obrobionych wykańczająco przez szlifowanie i docieranie oraz przez powierzchniową obróbkę plastyczną przez nagniatanie ślizgowe. Podano także konstrukcje narzędzi i przykłady stosowania badanych metod obróbki.
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Extremal thermal loading of a bifurcation pipe
PublicationThe subject of considerations is a spherical bifurcation pipe of a live steam made of steel P91, which is an element of a block of coal-fired power plant working with a 18K370 turbine. As experience shows, it is a very sensitive element of the boiler pipelines. An extreme work scenario for such a block has been adopted, in which the turbine is shutting down to a warm state three times in 24 hours. This is an action dictated by...
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INVESTIGATION OF THE EFFECT OF THE ROCKET'S SUBORBITAL FLIGHT ON BIOFILM, ENZYMES AND BIOSYNTHESIS ON AUTONOMOUS, MODULAR AND SCALABLE PLATFORM FOR CONDUCTING EXPERIMENTS OF AN ASTROBIOTECHNOLOGICAL NATURE
PublicationWith new incentives for human space exploration, biotechnological experiments in orbit became imperative.Answering this need, we build an autonomous, modular, and scalable platform that enables those experiments onrockets. We called it AMBER. The aim of the payload of the R6 suborbital rocket is to perform an experiment tostudy the influence of rocket flights on biofilm, molecular...