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Search results for: molecular motors
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Mechanisms of Plant Natural Immunity and the Role of Selected Oxylipins as Molecular Mediators in Plant Protection
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Molecular identification and genotyping of Staphylococci: genus, species, strains, colnes, lineages, and interspecies exchanges
PublicationStaphylococci are increasingly recognized as etiological agents of many opportunistic human and animal infections, emphasizing the need for a rapid and accurate identification, even to a genotypical level of these bacteria. In the recent years, there has been a significant progress in typing and phylogenetic study of Staphylococcus species. Here, we describe molecular methods used in taxonomy as well as staphylococci characterization....
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Molecular dynamics study on the role of solvation water in the adsorption of hyperactive AFP to the ice surface
PublicationUsing computer simulations, the early stages of the adsorption of the CfAFP molecule to the ice surface were analyzed. We found that the ice and the protein interact at least as early as when the protein is about 1 nm away from the ice surface. These interactions are mediated by interfacial solvation water and are possible thanks to the structural ordering of the solvent. This ordering leads to positional preference of the protein...
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Furan Fragmentation in the Gas Phase: New Insights from Statistical and Molecular Dynamics Calculations
PublicationWe present a complete exploration of the different fragmentation mechanisms of furan (C4H4O) operating at low and high energies. Three different theoretical approaches are combined to determine the structure of all possible reaction intermediates, many of them not described in previous studies, and a large number of pathways involving three types of fundamental elementary mechanisms: isomerization, fragmentation, and H/H2 loss...
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Low-energy electron scattering from molecular hydrogen: Excitation of the X1Σg+ to b3Σu+ transition
PublicationWe present time-of-flight differential cross-section measurements and convergent close-coupling calculations of differential cross sections for the electron-impact excitation of the X 1 g + → b 3 u + transition in molecular hydrogen. A part of this work was recently published [M. Zawadzki et al., Phys. Rev. A 97, 050702(R) (2018)]. In this work, agreement between theory and experiment is excellent overall, and marks a transition...
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Structure of the interlayer between Au thin film and Si-substrate: Molecular Dynamics simulations
PublicationInteraction between 2, 3, 5 and 7 atomic layers of gold and a (111) silicon surface was investigated with the molecular dynamics simulation method. The simulation of the diffusion interaction between gold and silicon in the temperature range 425-925 K has been carried out. The peculiarities of the concentration changes of the interacting components and the atomic density at the boundary...
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Nanomechanical Properties of Metallic fcc Nanorods from Molecular Simulations with the Sutton-Chen Potential
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Autofagia: mechanizm molekularny, apoptoza i nowotwory = Autophagy: molecular mechanism, apoptosis and cancer
PublicationW pracy omówiono molekularny mechanizm autofagii oraz najważniejsze szlaki sygnałowe uczestniczące w regulacji przebiegu tego procesu w komórkach nowotworowych. Omówiona została również dwojaka rola autofagii w procesie nowotworzenia oraz skutki zarówno indukcji, jak i inhibicji autofagii w terapii przeciwnowotworowej
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Thermodynamics and kinetics of amphotericin B self-association in aqueous solution characterized in molecular detail
PublicationAmphotericin B (AmB) is a potent but toxic drug commonly used to treat systemic mycoses. Its efficiency as a therapeutic agent depends on its ability to discriminate between mammalian and fungal cell membranes. The association of AmB monomers in an aqueous environment plays an important role in drug selectivity, as oligomers formed prior to membrane insertion – presumably dimers – are believed to act differently on fungal (ergosterol-rich)...
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Assessment of Sewage Molecular Markers: Linear Alkylbenzenes in Sediments of an Industrialized Region in Peninsular Malaysia
PublicationIn this study, the use of linear alkylbenzenes (LABs) was employed to pinpoint the sources of human activity that cause detrimental impacts on the coastal environment and river ecosystems. LABs were detected using GC–MS in sediment samples assembled from Kim Kim River (KKR) and the Port Dickson coast (PDC). To assess the significance of variations in the distribution and concentrations of LABs across the sampling sites, this study...
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Molecular basis and quantitative assessment of TRF1 and TRF2 protein interactions with TIN2 and Apollo peptides
PublicationShelterin is a six-protein complex (TRF1, TRF2, POT1, RAP1, TIN2, and TPP1) that also functions in smaller subsets in regulation and protection of human telomeres. Two closely related proteins, TRF1 and TRF2, make high-affinity contact directly with double-stranded telomeric DNA and serve as a molecular platform. Protein TIN2 binds to TRF1 and TRF2 dimer-forming domains, whereas Apollo makes interaction only with TRF2. To elucidate...
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Molecular basis of the osmolyte effect on protein stability: a lesson from the mechanical unfolding of lysozyme
PublicationOsmolytes are a class of small organic molecules that shift the protein folding equilibrium. For this reason, they are accumulated by organisms under environmental stress, and find applications in biotechnology where proteins need to be stabilized or dissolved. However, despite years of research, debate continues over the exact mechanisms underpinning the stabilizing and denaturing effect of osmolytes. Here, we simulated the mechanical...
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TIME-OF-FLIGHT DIFFERENTIAL ELECTRON SCATTERING FROM MOLECULAR TARGETS: BENCHMARK CROSS SECTIONS
PublicationWe report time-of-flight differential cross section (DCS) measurements for the electron impact excitation transition in H2. In this work, agreement between available theory and experiment is excellent overall, and marks a transition in electron molecule scattering where differential scattering of excitation is found to be in such precise agreement. We also prove that the newly built apparatus can be used for accurate measurement...
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Chitosan-Based Membranes as Gentamicin Carriers for Biomedical Applications — Influence of Chitosan Molecular Weight
PublicationOver the past decade, much attention has been paid to chitosan as a potential drug carrier because of its non-toxicity, biocompatibility, biodegradability and antibacterial properties. The effect of various chitosan characteristics on its ability to carry different antibiotics is discussed in the literature. In this work, we evaluated the influence of the different molecular weights of this polymer on its potential as an antibacterial...
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Measurements of differential cross sections for elastic electron scattering in the backward direction by molecular oxygen.
PublicationZmierzono różniczkowe przekroje czynne na rozproszenie sprężyste elektronów na cząsteczkach tlenu w zakresie kątów rozproszenia 100-180 st., dla wybranych energii padających elektronów w przedziale 7-20eV. Do pomiarów wykorzystano metodę lokalnego pola magnetycznego.
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Molecular aspects of biogenesis of Escherichia coli Dr Fimbriae: characterization of DraB-DraE complexes
PublicationHemaglutynina Dr uropatogennych szczepów Escherichia coli jest fimbrialnym homopolimerem zbudowanym z podjednostek białkowych DraE kodowanych przez operon dra. Operon dra zawiera geny draB i draC, kodujące białka homologiczne do białek (białko opiekuńcze-białko kanałotwórcze) zaangażowanych w procesie biogenezy struktur polimerycznych eksprymowanych powierzchniowo. Białko DraB jest jednym z białek periplazmatycznych, należącym...
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Some problems of self-excited vibrations of turbine rotors. Part I: The theoretical method
PublicationPrzedstawiono teoretyczną metodę określania uszczelnienia nadbandażowego lub dławicy zupełnej, które odgrywa największą rolę w generowaniu samowzbudnych drgań typu aerodynamicznego wirników turbinowych. Drgania harmoniczne układu wirnika turbiny opisane są macierzowym równaniem, a wymuszenia aerodynamiczne określane metodą współczynników wpływu.
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3D Hand Shape Modeling for Automatic Assessing Motor Performance in Parkinson's Disease
PublicationIn this paper a method for hand pattern processing to create a 3D hand model is presented. By applying a complete hand armature to the model obtained, an interpolation of three motor tests for an individual Parkinson's disease patient can be performed. To obtain the 3D hand model the top view of the hand from a web cam is analyzed. The hand contour is examined to find characteristic points that allows for dividing hand image into...
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Research on a control system based on stepping motor for ship's controllable pitch propellers
PublicationW artykule przedstawiono opis stanowiska laboratoryjnego do badania serwomechanizmów okrętowych śrub nastawnych małej mocy oraz opracowany układ sterowania zdalnego śruby z wykorzystaniem elektrycznego silnika krokowego. Przedstawiono także wyniki pierwszej serii badań układu sterowania śruby nieobciążonej dla skokowego zadawanych wartości skoku śruby przy dwóch różnych prędkościach obrotowych silnika krokowego.
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Nonlinear control of induction motor in field weakning region with consideration of stator flux
PublicationMetody nieliniowgo sterowania mogą poprawić właściwości silnika indukcyjnego w stanach przejściowych wektora strumienia. Badano sterowanie oparte na modelu multiskalarnym silnika indukcyjnego w zakresie osłabiania pola. Dwie nowe zmienne wejściowe pojawiające się w modelu multiskalarnym są równe czynnej i biernej mocy silnika. Pokazano, że te wielkości mogą byc kompensowane, jeżeli rozważane są jako mierzone zakłócenia. Maksymalny...
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Increasing Electric Vehicles Reliability by Non-Invasive Diagnosis of Motor Winding Faults
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Stability of a proportional observer with additional integrators on the example of the flux observer of induction motor
PublicationArtykuł opisuje zagadnienia związane ze stabilnością proporcjonalnego obserwatora Luenbergera z dodatkowymi integratorami
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Induction Motor Multiscalar Model Based Sensorless Control Using Power Measurement
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Five-phase Induction Motor Drive Operation During Stator Phase Fault
PublicationThe article presents the most important advantages of multi-phase electric drives. The construction of a five-phase squirrel cage induction motor together with possible stator winding distribution cases is presented, which affect the properties of such motor. Increased reliability of five-phase drives was indicated. The drive operation properties were confirmed by experimental results.
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Resonant DC link inverters for AC motor drive systems – critical evaluation
PublicationIn this survey paper, resonant and quasiresonant DC link inverters are reexamined for AC motor drive applications. Critical evaluation of representative topologies is based on simulation and waveform analysis to characterize current/voltage stress of components, control timing constraints and feasibility. A special concern over inverter common-mode voltage and voltage gradient du/dt limitation capacity is discussed for motor bearing...
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Influence of water and mineral oil on the leaks in satellite motor commutation unit clearances
PublicationThe article describes the flow rates of mineral oil and water flowing, as working media, through the commutation unit of a hydraulic satellite motor. It is demonstrated that geometrical dimensions of commutation unit clearances change as a function of the machine shaft rotation angle. Methods for measuring the rate of this flow and the pressure in the working chamber are presented. The results of pressure measurements in the working...
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Supply current signal and artificial neural networks in the induction motor bearings diagnostics
PublicationThis paper contains research results of the diagnostics of induction motor bearings based on measurement of the supply current with usage of artificial neural networks. Bearing failure amount is greater than 40% of all engine failures, which makes their damage-free operation crucial. Tests were performed on motors with intentionally made bearings defects. Chapter 2 introduces the concept of artificial neural networks. It presents...
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Sensorless Disturbance Detection for Five Phase Induction Motor with Third Harmonic Injection
PublicationThe paper presents a sensorless disturbance detection procedure that was done on a five phase induction motor with third harmonic injection. A test bench was developed where a three phase machine serves as disturbance generator of different frequencies. The control of the machines is based on multi scalar variables that ensures an independent control of the motor EMF and the rotor flux. For disturbance identification a speed observer...
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Selected dynamic properties of adaptive proportional observer of induction motor state variables
PublicationThis paper presents problems related to the design and the stability of adaptive proportional observer which is used for estimation of magnetic flux and motor speed in sensorless control systems of induction motor. The gain matrix of the observer was chosen by genetic algorithm and alternatively by pole placement method. It has been shown that adaptive proportional observer is stable if the...
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Properties of water in the region between a tubulin dimer and a single motor head of kinesin
PublicationA kinesin is a molecular motor that can perform movement on a microtubule track in a stepping-like manner. This motion is connected with processes of association and dissociation of kinesin and tubulin. Water is an important participant in these kinds of molecular interactions. This is why we have decided to investigate the dynamical and structural properties of water in the region between the kinesin catalytic domain and the tubulin...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublicationBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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Current based Normalized Triple Covariance as a bearings diagnostic feature in induction motor
PublicationDiagnosis of induction motors, conducted remotely by measuring and analyzing the supply current is attractive with the lack of access to the engine. So far there is no solution, based on analysis of current, the credibility of which allow use in industry. Statistics of IM bearing failures of induction motors indicate, that they constitute more than 40% of IM damage, therefore bearing diagnosis is so important. The article provides...
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Design Evolution of the Ultrasonic Piezoelectric Motor Using Three Rotating Mode Actuators
PublicationThe development process and experimental investigation of the multicell piezoelectric motor is presented in this paper. The proposed design consists of three individual cells integrated into the stator, double rotor, and a preload system. Those elements are combined into a symmetrical structure of the motor. The two new prototypes have been designed, simulated and tested. Finite element numerical analysis is carried out to obtain...
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Influence of geometrical and operational parameters on tooth wear in the working mechanism of a satellite motor
PublicationThis article describes the phenomena affecting the wear of the rotor of the working mechanism in a hydraulic satellite motor. The basic geometrical relationships that allow the calculation of the coordinates of the points of contact between the satellite and the rotor and the curvature are presented. A method for calculating the number of contacts of the satellite teeth with the rotor teeth and of the satellite teeth with the curvature...
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Influence of operating pressure on the durability of a satellite hydraulic motor supplied by rapeseed oil
PublicationThis 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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The computer numerical control system with permanent magnet synchronous motor servo-drives.
PublicationPrzedstawiono układ serwonapędów wieloosiowej maszyny sterowanej numerycznie. W układzie wykorzystano silniki synchroniczne z magnesami trwałymi oraz procesory synałowe DSP. Omówiono algorytmy sterowania nadrzędnego oraz problemy sterownia silnika PMSM.
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Determination of equivalent circuit parameters of an induction motor using field calculation software
PublicationSimulation of the drive system comprising a power electronic converter and an induction motor requires that the equivalent circuit parameters of the motor are known. These parameters can be either measured or calculated. A method of calculation of self and mutual inductances that are parameters of a polyphase model of the motor is presented in the paper. All self-inductances and mutual inductances have been calculated using the...
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Model and simulation tests of a squirrel-cage induction motor with oscillation of air gap
PublicationPrzedstawiono model matematyczny silnika, który pozwala na wprowadzanie ekscentryczności wirnika. Zaprezentowano obliczone widma prądu z wprowadzoną oscylacją wirnika, co z pewnym przybliżeniem odpowiada uszkodzeniu łożyska. Rezultaty symulacji pozwalają na określenie zależności pomiędzy oscylacją szczeliny powietrznej i składowych w widmie prądu.
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Intelligent Systems in Molecular Biology
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Transcriptomic landscape of blood platelets in healthy donors
PublicationBlood platelet RNA-sequencing is increasingly used among the scientific community. Aberrant platelet transcriptome is common in cancer or cardiovascular disease, but reference data on platelet RNA content in healthy individuals are scarce and merit complex investigation. We sought to explore the dynamics of platelet transcriptome. Datasets from 204 healthy donors were used for the analysis of splice variants, particularly with...
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Student model representation for pedagogical virtual mentors
PublicationThe paper concerns technological aspects of virtual mentors construction, especially concentrating on the student model representation. The article distinguishes several types of information that is gathered by the pedagogical agents and other educational platforms, including student knowledge model, student progress tracking, interaction process patterns and learner preferences. A set of technologies used for the student model...
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Interval vertex-coloring of a graph with forbidden colors
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Interval Vertex-Coloring of a Graph With Forbidden Colors
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Interval edge coloring of a graph with forbidden colors
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The situation of young mothers in the Polish labour market
PublicationThe purpose of the article is to present the situation of young women combining professional and paternal responsibilities in the Polish labour market. The papaer presents the results of interviews conducted with six young mothers.
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Transcriptomic landscape of blood platelets in healthy donors
PublicationBACKGROUND Blood platelet RNA-sequencing is increasingly used among the scientific community. Aberrant platelet transcriptome is common in cancer or cardiovascular disease, but reference data on platelet RNA content in healthy individuals are scarce and merit complex investigation. METHODS We sought to explore the dynamics of platelet transcriptome. Datasets from 204 healthy donors were used for the analysis of splice variants,...
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On hydrodynamic forces acting on the ship in large motions.
PublicationPraca zapoznaje czytelnika ze współczesnym stanem dynamiki statku w nieliniowym ujęciu, ukierunkowanym na unikanie zbyt daleko idących komplikacji w rozwiązaniu. Nieliniowość dotyczy przede wszystkim sił Fronda-Kryłowa oraz sił tłumienia po wejściu pokładu do wody, czy też oporu stępek przechyłowych. Do pozostałych sił towarzyszących i dyfrakcyjnych stosuje się ekstrapolację podejścia liniowego.
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Robustness of the Rotor-router Mechanism
PublicationW pracy rozważano model eksploracji grafu nieskierowanego przez pojedynczego agenta, w którym sterowanie agentem odbywa się zgodnie z zasadą ''rotor-router'' (inaczej: ''Propp machine''). Przeanalizowano czas stabilizacji agenta do trajektorii w postaci cyklu Eulera w przypadku wystąpienia zaburzeń w grafie: usunięcie krawędzi, dodanie krawędzi, lokalna zamiana portów
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HYBRID REDUCED MODEL OF ROTOR
PublicationIn the paper, the authors describe the method of model reduction of a rotor system. The proposed approach enables to obtain a low order model including e.g. nonproportional damping or the gyroscopic effect. This method is illustrated using the example of a rotor system. First, a model of the system was built without gyroscopic and damping effects by using the rigid finite element method. Next, this model was reduced. Finally, two...
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DNA Computing and Molecular Programming (International Meeting on DNA Computing and Molecular Programming)
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