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Search results for: GEAR VIBRATIONS
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Application of neural networks for identification of forcedness having effect on magnitude of turbine rotor vibration using rotor trajectory.
PublicationW pracy dokonano analizy zastosowania sieci neuronowych do wyznaczenia wartości wymuszeń wpływających na wielkość drgań wirnika używając trajektorii jako parametr określający drgania. Badania przeprowadzono na powietrznej, jednostopniowej turbinie modelowej. Przemieszczenia poziome i pionowe wirnika turbiny mierzono przy pomocy systemu pomiarowego i rejestrowano na oscyloskopie cyfrowym. Przeprowadzono pomiary trajektorii ruchu...
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The optimal control at energy performance index as a rule for vibration surveillance in the hybrid system by on example of milling flexible details
PublicationPraca dotyczy nadzorowania drgań w niestacjonarnych układach mechanicznych za pomocą sterowania optymalnego pry energetycznym wskaźniku jakości. W układzie drgającym wyodrębniono podukłady: modalny, strukturalny oraz łączący. Dynamikę układu sterowanego opisano we współrzędnych hybrydowych. Przedstawiono przykład nadzorowania drgań podczas obróbki przedmiotów podatnych smukłym frezem kulistym. Paramatry obliczeniowego modelu modalnego...
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Characterization of Corrosion-Induced Fracture in Reinforced Concrete Beams Using Electrical Potential, Ultrasound and Low-Frequency Vibration
PublicationThe paper deals with the non-destructive experimental testing of the reinforced concrete beams under progressive corrosion. A series of experiments using electrical potential, ultrasound and low-frequency vibrations techniques are reported. Electrical potential and natural frequencies were used to characterise and monitor the corrosion process at its initial state. The P-wave velocity measurements were proved to be effective in...
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Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches
PublicationThis paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite...
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DYNAMIC RESPONSE OF FORUM GDANSK STRUCTURE DUE TO RAIL TRAFFIC
PublicationThe paper presents the study of the impact of vibration induced by the movement of the railway rolling stock on the Forum Gdańsk structure. This object is currently under construction and is located over the railway tracks in the vicinity of the Gdańsk Główny and Gdańsk Śródmieście railway stations. The analysis covers the influence of vibrations on the structure itself and on the people within. The in situ measurements on existing...
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Motor bearing diagnostics performed by means of laser vibrometer
PublicationDamage of bearings is the most common cause of failures in squirrel-cage induction motors. That is why the issues connected with diagnostics of bearings are so important. The equipment employed for bearing diagnostics usually makes use of vibrations as the criterion for technical condition of the bearings. This paper presents exemplary results of the research conducted on bearings with artificially introduced damage. A scanning...
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Vibrational Sum-Frequency Generation Activity of a 2,4-Dinitrophenyl Phospholipid Hybrid Bilayer: Retrieving Orientational Parameters from a DFT Analysis of Experimental Data
PublicationThe vibrational nonlinear activity of films of 2,4-dinitrophenyl phospholipid (DNP) at the solid interface is measured by sum-frequency generation spectroscopy (SFG). Hybrid bilayers are formed by a LangmuirSchaefer approach in which the lipid layer is physisorbed on top of a self-assembled monolayer of dodecanethiol on Pt with the polar heads pointing out from the surface. The SFG response is investigated in two vibrational frequency...
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Patient with metastatic breast cancer presenting as acute cholecystitis with one-year survival on hormonotherapy
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A 5-Year Experience with Laparoscopic Adjustable Gastric Banding—Focus on Outcomes, Complications, and Their Management
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Creation of structures by 4, 5 and 6-year-old children, considering the conditions for the structure
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Increase in wear resistance of nickel plasma coatings under traditional and combined treatment conditions
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The impact of laser surface treatment on the microstructure, wear resistance and hardness of the AlMg5 aluminum alloy
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Ultraviolet to near-infrared down-conversion in Bi3+–Yb3+ co-doped YAM phosphor
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Use of personal knowledge of 8-year-old students in creative solving of technical tasks
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Arterial structure and function in subjects with acute coronary syndrome after one-year of treatment
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Which Target Blood Pressure in Year 2018? Evidence from Recent Clinical Trials
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Safety of Bariatric Surgery in ≥ 65-Year-Old Patients During the COVID-19 Pandemic
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Amide/Amino-Based Functional Additives for Lubricants: Structure, Antimicrobial Activity and Wear Resistance
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Graffiti saves birds: A year-round pattern of bird collisions with glass bus shelters
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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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Intensification of thermal convection near electric devices using flat screens – computer modelling
PublicationIntensification of natural thermal convection near electric devices is possible by application of additional elements as screens creating convection canals close to the device. In the earlier authors paper the results of the analysis of thermal convection with the use of only one additional screen close to the electric device were presented. This paper presents computer modelling of thermal convection when two screens near the...
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Algorithm for Automatic Wear Estimation of Railway Contact Strips Based on 3D Scanning Results
PublicationElectric rail vehicles use current collection system which consists of overhead contact line and a current collector (pantograph) mounted on the roof of a vehicle. A pantograph is equipped with contact strips, which slide along the contact wire, ensuring steady electric contact. Contact strips are made of carbon layer, fixed to an aluminum carrier. The carbon layer wears down due to friction. Using overly worn contact strips increases...
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Extraction of antenna pattern from near field antenna measurements distorted by undesired emission
PublicationIn this paper authors present experimental correction of antenna pattern obtained from near field measurements when they are distorted by determined electromagnetic emission. Such situation may be met e.g. when feeding or supply subsystem interacts with antenna radiation pattern due to self-emission. Presented results of experiments show effectiveness of extraction of antenna pattern utilizing near field antenna measurements.
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Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublicationResults of a study to examine a unique idea of self-levitating journal bearing are presented in this paper. the idea represents a radical departure from the current bearing technology. it utilisesacoustic levitation, which relies on the sound energy radiated by an object supporting a load. acoustic levitation has been demonstrated to support loads of up to 10 kg. in order to support a load theacoustic wave emitted by the radiating...
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Wear of Ultra-thin DLC or Tungsten-modified DLC Coatings under Reciprocating Sliding
PublicationIn the paper results are presented from tests in reciprocating sliding of self mated specimens of DLC and tungsten modified DLC coatings on stainless steel substrate. The contact geometry chosen for the research task was ball on flat. The contacts were lubricated either with distilled water or medical saline solution. Results are presented with regard to wear resistance as a function of material type and lubricant used.
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Effect of chemical composition on corrosion and wear behaviour of the composite Ni-Fe-Al2O3 coatings.
PublicationPrzedstawiono wyniki badań powłoki kompozytowej otrzymanej przez osadzanie katodowe galwaniczne w roztworze zawierającym sole niklu, żelaza oraz cząstki ceramiki Al2O3 o różnej wielkości i stężeniu. Wykazano, że charakterystyka ceramiki posiada wpływ na szybkość korozji i zużycia ściernego. W szczególności, zawartość ceramiki wpływa dodatnio na odporność na zużycie ścierne, ale nieco obniża odporność na zużycie korozyjne.
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Tool Wear Monitoring Using Improved Dragonfly Optimization Algorithm and Deep Belief Network
PublicationIn recent decades, tool wear monitoring has played a crucial role in the improvement of industrial production quality and efficiency. In the machining process, it is important to predict both tool cost and life, and to reduce the equipment downtime. The conventional methods need enormous quantities of human resources and expert skills to achieve precise tool wear information. To automatically identify the tool wear types, deep...
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Issue of changes in technical states of a diesel engiene as the result of wear of its tribological systems
PublicationWskazano na konieczność rozpatrywania procesów obciążeń i zużywania układów tribologicznych silników o zapłonie samoczynnym (a zatem również zmiany ich stanów) w warunkach rzeczywistych jako procesów losowych. Oznacza to, że matematycznymi modelami tych procesów mogą być funkcje losowe o argumencie, którym jest czas (t) i o wartościach, którymi są zmienne losowe takie jak obciążenia i zużycia poszczególnych układów tribologicznych....
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Chemical, Physical, and Mechanical Properties of 95-Year-Old Concrete Built-In Arch Bridge
PublicationThis research aimed to determine the durability and strength of an old concrete built-in arch bridge based on selected mechanical, physical, and chemical properties of the concrete. The bridge was erected in 1925 and is located in Jagodnik (northern Poland). Cylindrical specimens were taken from the side ribs connected to the top plate using a concrete core borehole diamond drill machine. The properties of the old concrete were...
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A 95-Year-Old Concrete Arch Bridge: From Materials Characterization to Structural Analysis
PublicationThe structural analysis of a 95-year-old concrete arch bridge located in Jagodnik (Poland) is performed in this paper, in order to check its behavior under today’s traffic loads. The mechanical properties of both the concrete and the reinforcement are investigated by testing cores and bar stubs extracted from the bridge. Structural analysis confirms that the bridge meets today’s load requirements in terms of bearing capacity, serviceability...
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Wear Resistance Enhancement of Al6061 Alloy Surface Layer by Laser Dispersed Carbide Powders
PublicationIn this paper, results of the experimental study on improving wear resistance in sliding friction of Al-based alloy are presented. The technique used involves the formation of a metal matrix composite (MMC) in the alloy surface layer by laser dispersion of carbide powders such as WC, TiC and SiC. For WC and TiC MMC surface coatings fabricated under conditions typical for most of the technologically relevant solid-state lasers (wavelength...
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Methylene Blue Near-Infrared Fluorescence Imaging in Breast Cancer Sentinel Node Biopsy
PublicationIntroduction: Fluorescence-based navigation for breast cancer sentinel node biopsy is a novel method that uses indocyanine green as a fluorophore. However, methylene blue (MB) also has some fluorescent properties. This study is the first in a clinical series presenting the possible use of MB as a fluorescent dye for the identification of sentinel nodes in breast sentinel node biopsy. Material and methods: Forty-nine patients with...
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Study on Dry Sliding Wear and Friction Behaviour of Al7068/Si3N4/BN Hybrid Composites
PublicationHybrid aluminium metal matrix composites have the potential to replace single reinforced aluminium metal matrix composites due to improved properties. Moreover, tribological performance is critical for these composites, as they have extensive application areas, such as the automotive, aerospace, marine and defence industries. The present work aims to establish the tribological characteristics of Al7068/Si3N4/BN hybrid metal matrix...
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Unusual dynamic properties of water near the ice-binding plane of hyperactive antifreeze protein
PublicationThe dynamical properties of solvation water of hyperactive antifreeze protein from Choristoneura fumiferana (CfAFP) are analyzed and discussed in context of its antifreeze activity. The protein comprises of three well-defined planes and one of them binds to the surface of ice. The dynamical properties of solvation water around each of these planes were analyzed separately; the results are compared with the dynamical properties...
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Influence of pulse waves on the transmission of near-infrared radiation in outer-head tissue layers.
PublicationIn this study, we investigate the effect of pulse waves on the transmission of near-infrared radiation in the outer tissue layers of the human head. This effect is important in using optical radiation to monitor brain conditions based on measuring the transmission changes in the near-infrared radiation between the source and the detector, placed on the surface of the scalp. This is because the signal related to the changes in the...
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Influence of local bush wear on water lubricated sliding bearing load carrying capacity
PublicationOne of main problems concerning water-lubricated bearings is their durability. There are known cases of bearings with life time measured in decades, and some, whose refurbishment was necessary just days after start-up. Obtaining stable fluid film friction plays key role in the durability of these bearings. Unfortunately, their load-carrying capacity is limited due to water's low-viscosity. The conducted experimental...
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Influence of local bush wear on properties of water lubricated marine stern tube bearings
PublicationW artykule przedstawiono propozycję metody obliczania łożysk ślizgowych smarowanych cieczą o niskiej lepkości (wodą) w których doszło do lokalnego zużycia panwi. Proponowana metoda uwzględnia sprężystą deformację panwi (model EHL) oraz zmianę geometrii będącą wynikiem zużycia.
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Theoretical study of the structure, energetics and vibrational frequencies of water-acetone and water-2-butanone complexes
PublicationKompleksy acetonu i 2-butanonu z 0-2 cząsteczkami wody połączonymi wiązaniem wodorowym z tlenem karbonylowym zbadano z wykorzystaniem teorii funkcjonału gęstości (DFT) na poziomie B3LYP/6-311++G(d,p). Obliczenia w fazie gazowej uzupełniono o optymalizacje w otoczeniu rozpuszczalnika, symulowanego za pomocą modelu polaryzowalnego kontinuum (PCM). Częstości drgań oscylacyjnych otrzymane na podstawie zależności empirycznej sa zgodne...
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Road mortality of pond-breeding amphibians during spring migrations in the Mazurian Lakeland, NE Poland
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Vibration surveillance during ball end milling of curved flexible details on a basis of assessment of assurance of the model of real object
PublicationW pracy przedstawiono nową metodę nadzorowania drgań podczas frezowania zakrzywionych przedmiotów podatnych. Wykorzystano model modalny przedmiotu obrabianego, którego parametry zidentyfikowano na bazie badań doświadczalnych oraz analizy komputerowej. Zastosowanie modelu metody elementów skończonych, którego zachowanie jest zgodne z przedmiotem uformowanym w postaci cienkościennej powierzchni półwalcowej, a następnie - utworzenie...
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A LUMPED-CIRCUIT MODEL OF CIRCULAR PISTON TRANSDUCER FOR MODELING ITS PERFORMANCE IN DUAL FREQUENCY OPERATING MODES
PublicationThe paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and ra dial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. Th e approximate solution for harmonic case is represented in the form of 4x4 matrix, which is syn thesized...
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Epigenetic inhibitor zebularine activates ear pinna wound closure in the mouse
PublicationBackground:Most studies on regenerative medicine focus on cell-based therapies and transplantations.Small-molecule therapeutics, though proved effective in different medical conditions, have not been extensivelyinvestigated in regenerative research. It is known that healing potential decreases with development and devel-opmental changes are driven by epigenetic mechanisms, which suggests epigenetic repression of regenerativecapacity.Methods:We...
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Retrospective analysis of genetic diversity of Klebsiella oxytoca isolated in Poland over a 50-year period.
PublicationAnaliza genetyki populacji i określenie powiązań filogenetycznych pomiędzy szczepami może być niezwykle użytecznym podejściem w określaniu rozprzestrzeniania się wzorów genetycznych różnych gatunków bakterii na potrzeby epidemiologiczne. Nie ma danych, które opisywałyby długoterminowe sytuacje epidemiologiczne powodowane przez wielolekooporne, oportunistyczne szczepy Klebsiella oxytoca metodami molekularnymi. Celem przedstawionych...
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The feasibility and economic efficiency of selective modernization solutions in a singlefamily house located in Siemianice near Słupsk
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A General Scheme of a Branch-and-Bound Approach for the Sensor Selection Problem in Near-Field Broadband Beamforming
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Hidden Structural Evolution and Bond Valence Control in Near-Infrared Phosphors for Light-Emitting Diodes
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Chromium Ion Pair Luminescence: A Strategy in Broadband Near-Infrared Light-Emitting Diode Design
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Ways of shaping love for God and people and historical memory during the Year of St. Stanislaus Kostka
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Privacy-Preserving, Scalable Blockchain-Based Solution for Monitoring Industrial Infrastructure in the Near Real-Time
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Application of image processing methods for the characterization of selected features and wear analysis in surface topography measurements
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