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Search results for: lubrication failure,bearing seizure,water-lubricated bearing,non-metallic bearing,sliding bearing
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Free convection of water-Al2O3 nanofluid from horizontal porous coated tube
PublicationNanofluids are expected to enhance heat transfer in many thermal systems. Present efforts are concentrated on boiling heat transfer of nanofluids, although single phase convection is of key importance in various appliances such as car radiators or heating systems. This paper presents experimental results of heat transfer during free convection of water-Al3O3 nanofluid from horizontal tube covered with metallic porous coating. Contrary...
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Field investigation of low-temperature cracking and stiffness moduli on selected roads with conventional and high modulus asphalt concrete
PublicationHigh Modulus Asphalt Concrete (HMAC) was introduced in Poland as a one of the solutions to the problem of rutting, type of deterioration common in the 1990s. After first encouraging trials in 2002 HMAC was widely used for heavily loaded national roads and motorways. However some concerns were raised about low-temperature cracking of HMAC. This was the main reason of the studies presented in this article were started. The article...
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The Reactivity of Phosphanylphosphinidene Complexes of Transition Metals Toward Terminal Dihaloalkanes
PublicationThe reactivities of phosphanylphosphinidene complexes [(DippN)2W(Cl)(η2-P−PtBu2)]− (1), [(pTol3P)2Pt(η2- P=PtBu2)] (2), and [(dppe)Pt(η2-P=PtBu2)] (3) toward dihaloalkanes and methyl iodide were investigated. The reactions of the anionic tungsten complex (1) with stochiometric Br(CH2)nBr (n = 3, 4, 6) led to the formation of neutral complexes with a tBu2PP(CH2)3Br ligand or neutral dinuclear complexes with unusual tetradentate...
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Study on deformed steel columns subjected to impact load due to soft-storey failure in buildings during earthquakes
PublicationThe so called soft-storey failure is one of the most typical types of damage induced in buildings as the result of earthquake excitation. It has been observed during ground motions that the failure of an upper soft storey of a structure results in large vertical impact load acting on the lower floors. If the resistance of the structural members of the lower storeys is not sufficient it may further lead to progressive collapse of...
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Assessment of Failure Occurrence Rate for Concrete Machine Foundations Used in Gas and Oil Industry by Machine Learning
PublicationConcrete machine foundations are structures that transfer loads from machines in operation to the ground. The design of such foundations requires a careful analysis of the static and dynamic effects caused by machine exploitation. There are also other substantial differences between ordinary concrete foundations and machine foundations, of which the main one is that machine foundations are separated from the building structure....
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Risk of power cables insulation failure due to the thermal effect of solar radiation
PublicationLow-voltage, as well as high-voltage power cable lines, are usually buried in the ground. The ampacity of the power cables in the ground mainly depends on the thermal resistivity of the soil, which may vary in a wide range. A common practice in power cable systems performance is to supply them from a pole of an overhead line. If so, a section of the line is located in free air and can be directly exposed to solar radiation. In...
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Non-isolating 2-bondage in graphs
PublicationA 2-dominating set of a graph G=(V,E) is a set D of vertices of G such that every vertex of V(G)D has at least two neighbors in D. The 2-domination number of a graph G, denoted by gamma_2(G), is the minimum cardinality of a 2-dominating set of G. The non-isolating 2-bondage number of G, denoted by b_2'(G), is the minimum cardinality among all sets of edges E' subseteq E such that delta(G-E') >= 1 and gamma_2(G-E') > gamma_2(G)....
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Effect of wear on EHD film thickness in sliding contacts
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Fatigue test bearings with geometrically modyfied sliding surface.
PublicationW artykule uzasadniono celowość wprowadzenia nowego łóżyska testowego do badań wytrzymałości zmęczeniowej materiałów łożyskowych. Przedstawiono wstępne wyniki badań łożysk o zmodyfikowanej geometrii powierzchni ślizgowej i porównano otrzymane wyniki testów przeprowadzonych przy użyciu o standartowej geometrii.
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The surface contact characteristics after sliding and rolling burnishing.
PublicationW pracy przedstawiono zastosowanie nowej metody SCGC i odpowiedniego programu komputerowego JKC do oceny pomierzonej mikrostereometrii powierzchni części maszyn, głównie na potrzeby kontroli jakości. Na przykładzie powierzchni nagniatanych wykazano cechy nowej metody: wizualizację ułatwiającą wyobrażenie pomierzonej sfery chropowatości, położenie w niej najważniejszych parametrów oceny (rozkład geometrycznej powierzchni kontaktu,...
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Role of reciprocating sliding testing in tribological materials engineering
PublicationPrzedstawiono wyniki badań oporu ruchu i zużycia skojarzeń o styku rozłożonym przy posuwisto-zwrotnym ślizganiu. Badano skojarzenia: żeliwo-stop aluminium przetapiany laserowo w warunkach kriogenicznych oraz żeliwo-kompozyt aluminium-żelazo otrzymany ''in situ''.
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Anodic titania nanotubes decorated with gold nanoparticles produced by laser-induced dewetting of thin metallic films
PublicationHerein, we combine titania layers with gold species in a laser-supported process and report a substantial change of properties of the resulting heterostructures depending on the major processing parameters. Electrodes were fabricated via an anodisation process complemented with calcination to ensure a crystalline phase, and followed by magnetron sputtering of metallic films. The obtained TiO2 nanotubes with deposited thin (5, 10...
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Aneta Łuczkiewicz prof. dr hab. inż.
PeopleI conduct research on the adaptive abilities of microorganisms and their potential use in supporting technological processes. I combine environmental engineering with elements of biomedical and materials engineering. I am interested in innovative methods for detecting clinically significant microorganisms in aquatic environments (so-called wastewater-based epidemiology) and advanced and practical solutions in the water management...
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Water Reuse - project 2022/2023
e-Learning Coursesw ramach tego kursu przekazywane są informacje związane z projektem prowadzonym przez Alinę Wargin. Kierownikiem przedmiotu jest prof. Krzysztof Czerwionka. This course provides information related to the project led by Alina Wargin. The head of the subject is prof. Krzysztof Czerwionka.
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Water Reuse - project 2023/2024
e-Learning Coursesw ramach tego kursu przekazywane są informacje związane z projektem prowadzonym przez Alinę Wargin. Kierownikiem przedmiotu jest prof. Krzysztof Czerwionka. This course provides information related to the project led by Alina Wargin. The head of the subject is prof. Krzysztof Czerwionka.
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Identification and antimicrobial resistance of Enterococcus spp. isolated from surface water
PublicationIn 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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A versatile and convenient preparation of unsymmetrical diaryl disulfides
PublicationWe have developed a convenient method for the synthesis of unsymmetrical diaryl disulfides under mild conditions in excellent yields. The described method is based on the straightforward preparation of 5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinane-2-sulfenyl bromide from readily available 5,5-dimethyl-2-thiolo-2-thioxo-1,3,2-dioxaphosphorinane or bis(5,5-dimethyl-2-thioxo-1,3,2-dioxaphosphorinan-2-yl) disulfide. The unsymmetrical...
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Synthesis and biological activity of mycophenolic acid-amino acid derivatives
PublicationIn search of new immunosuppressants, mycophenolic acid (MPA) was coupled with amino acid methyl esters followed by hydrolysis to analogs bearing free carboxylic groups. The obtained compunds were tested in vitro as growth inhibitors of lymphoid cell line (Jurkat) and human peripheral blood mononuclear cells (PBMC) from healthy donors. According to obtained results recovering of free carboxylic group increased their activity. Additionally,...
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POSSIBILITY OF ASSESSMENT OF OPERATION OF SLIDING BEARINGS IN PISTON-CRANK MECHANISMS OF DIESEL ENGINES WITH REGARD TO LOAD AND TIME OF CORRECT WORK OF THE BEARINGS BY APPLYING ACOUSTIC EMISSION AS A DIAGNOSTIC SIGNAL
PublicationAbstract: The paper presents a possibility of determining (assessing) operation of sliding bearings with multilayer bushings in crank-piston mechanisms of diesel engines. Properties of load and wear, particularly fatigue and abrasive, are characterized in general. Acoustic emission as a diagnostic signal was proved to be useful for detection of the wear of sliding and barrier layers. Results of measurements of acoustic emission...
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Journal of Failure Analysis and Prevention
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EUROPEAN JOURNAL OF HEART FAILURE
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Journal of Non-Oxide Glasses
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Non-coding RNA Research
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Current Heart Failure Reports
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Electronic Device Failure Analysis
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JOURNAL OF NON-EQUILIBRIUM THERMODYNAMICS
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Non-Coding RNA Investigation
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Reduction of Derivative pipeline effort in water turbine
PublicationThe paper presents an approach to evaluate and reduce the effort of the derivative pipeline in a water turbine of a hydrostatic power station in its vulnerable spots. Potential places of the biggest effort of the structure, as well as the coefficient of displacement and safety factor related to them were identified using FEM numerical method. Pipeline reinforcement was designed and made based on FEM analysis. Original technology...
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Pool Boiling of Water–Al2O3 and Water–Cu Nanofluids Outside Porous Coated Tubes
PublicationThis paper deals with pool boiling ofwater–Al2O3 and water–Cu nanofluids on porous coated, horizontal tubes. Commercially available stainless-steel tubes having 10 mm outside diameter and 0.6 mm wall thickness were used to fabricate a test heater. Aluminum porous coatings 0.15 mm thick with porosity of about 40% were produced by plasma spraying. A smooth tube served as a reference tube. The experiments were conducted under different...
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LONG-TERM RISK CLASS MIGRATIONS OF NON-BANKRUPT AND BANKRUPT ENTERPRISES
PublicationThis paper investigates how the process of going bankrupt can be recognized much earlier by enterprises than by traditional forecasting models. The presented studies focus on the assessment of credit risk classes and on determination of the differences in risk class migrations between non-bankrupt enterprises and future insolvent firms. For this purpose, the author has developed a model of a Kohonen artificial neural network to...
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Comparison of a tribological model and real component test methods for lubricated contacts
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INDUSTRIAL LUBRICATION AND TRIBOLOGY
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Mariusz Kaczmarek dr hab. inż.
PeopleReceived M.Sc., Eng. in Electronics in 1995 from Gdansk University of Technology, Ph.D. in Medical Electronics in 2003 and habilitation in Biocybernetics and Biomedical Engineering in 2017. He was an investigator in about 13 projects receiving a number of awards, including four best papers, practical innovations (7 medals and awards) and also the Andronicos G. Kantsios Award and Siemens Award. Main research activities: the issues...
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Investigations On Water Circulation in Animal Sea-Water Basins – On the Example of Seals′ Breeding Pools
PublicationThis paper presents general comments concerning investigations on water circulation in animal breeding pools containing sea water. As an example are given results of computer simulation of water circulation in seals’ breeding pools situated in Marine Station at Hel, belonging to Oceanographic Institute, Gdansk University. A mathematical model of three main pools was prepared with taking into account their inflow and outflow water...
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Kinetics studies of recrystallization process of metallic catalysts for ammonia synthesis
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On fatigue safety of metallic elements under static and dynamic loads.
PublicationGłównym celem monografii było wyznaczenie współczynników bezpieczeństwa i kryteriów projektowych z uwzględnieniem wpływu obciążeń statycznych oraz naprężeń średnich i resztowych na wytrzymałość zmęczeniową przy obciążeniach okresowych i/lub stochastycznych. Uzyskano to za pomocą wyznaczonych naprężeń równoważnych i równania Soderberga. Otrzymano kryteria w postaci zamkniętej i zgodnej z wzorem Milesa na trwałość zmęczeniową oraz...
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Ductile fracture prediction in thin metallic plates subjected to explosions
PublicationPraca dotyczy modelowania zniszczenia ciągłego. Zaprezentowano wyniki eksperymentów przeprowadzonych na płytach metalowych poddanych eksplozjom oraz wyniki jednoosiowych prób laboratoryjnych. Opisano przyjęty model prawa konstytutywnego oraz kryteriów zniszczenia. Przedstawiono identyfikację parametrów materiałowych dla przyjętego modelu. Zaprezentowano model numeryczny oraz wyniki symulacji które następnie porównano z wynikami...
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The allergic and irritating reactions to metallic implants with trauma - orthopaedic patients
PublicationThe article presents the analysis of clinical operation complications after the treatment of long bones by mean of ostheosynthesis with the use of metal implants and endoprothesoplastic of hip joints.
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Stability of borophene dispersion in water
Open Research DataThis dataset contains the results of the studies of stability of borophene dispersion in water (1 µg/µL) based on the measurements of absorbance of the solution using UV-VIS spectroscopy.
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abiotic degradation of chlorinated ethanes and ethenes in water
PublicationIntroduction Chlorinated ethanes and ethenes are among themost frequently detected organic pollutants of water. Theirphysicochemical properties are such that they can contaminateaquifers for decades. In favourable conditions, they canundergo degradation. In anaerobic conditions, chlorinatedsolvents can undergo reductive dechlorination.Degradation pathways Abiotic dechlorination is usuallyslower than microbial but abiotic dechlorination...
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Non-linear FEM analysis of pounding-involved response of buildings under non-uniform earthquake excitation
PublicationThe aim of the paper is to show the results of the study investigating the influence of non-uniform earthquake excitation, due to spatial seismic effects connected with the propagation of seismic wave, on the pounding-involved response of two buildings. The three-dimensional non-linear FEM analysis has been conducted using the detailed models of colliding structures. Acceleration records for different structural supports have been...
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A hierarchical observer for a non-linear uncertain CSTR model of biochemical processes
PublicationThe problem of estimation of unmeasured state variables and unknown reaction kinetic functions for selected biochemical processes modelled as a continuous stirred tank reactor is addressed in this paper. In particular, a new hierarchical (sequential) state observer is derived to generate stable and robust estimates of the state variables and kinetic functions. The developed hierarchical observer uses an adjusted asymptotic observer...
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Toxic Metals, Non-Metals and Metalloids in Bottom Sediments as a Geoecological Indicator of a Water Body’s Suitability for Recreational Use
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Probabilistic Assessment of Correlations of Water Levels in Polish Coastal Lakes with Sea Water Level with the Application of Archimedean Copulas
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Heart failure, unspecified - Female, 55 - Tissue image [9140730014146001]
Open Research DataThis is the histopathological image of ADRENAL GLAND tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
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Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems
PublicationA multi-objective methodology utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) linked to EPANET for trading-off pumping costs, water quality, and tanks sizing of water distribution systems is developed and demonstrated. The model integrates variable speed pumps for modeling the pumps operation, two water quality objectives (one based on chlorine disinfectant concentrations and one on water age), and tanks sizing cost...
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Robust Monitoring of Water Quality in Drinking Water Distribution System
PublicationThe paper develops a novel open loop set bounded observer for robust estimation of water quality in DWDS based on the advanced nonlinear quality dynamics model including disinfections by-products (DBPs). The observer utilises a cooperativeness of the quality dynamics model and is computationally efficient, hence applicable to on-line quality monitoring. The simulation results illustrate its good and sustainable performance.
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Entropy measures of heart rate variability for short ECG datasets in patients with congestive heart failure
PublicationWe investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (FuzzyEn) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length...
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Entropy Measures of heart rate variability for short ECG datasets in patients with congestive heart failure
PublicationWe investigated the usefulness of entropy measures calculated for short ECG series in distinguishing healthy subjects from patients with congestive heart failure (CHF). Four entropy measures were tested: Approximate Entropy (ApEn), Sample Entropy (SampEn), Fuzzy Entropy (Fuzzy En) and Permutation Entropy (PE), each computed for ECG series of 1000, 500, 250 and 100 RR intervals. We found that with a reduction of the data set length...
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Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
PublicationNonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s...