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Search results for: COUPLING DYNAMIC EQUATIONS
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Dressing chain equations associated with difference soliton systems
PublicationAnalogicznie do teorii równań różniczkowych solitonowych, wprowadzamy proce-durę ubierania pary Laxa. Stosujemy metodę dla budowy nowych rozwiązań napodstawie znanych. Wprowadza się uogólnione wielomiany Bella. Tworzy sięschemat dla ogólnych par Laxa w postaci wielomianów od pewnego automorfizmupierscieni. Podany został przykład równań Hiroty i Nahma.
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Nonlocal problems for functional partial differential equations of firstorder
PublicationRozważa się istnienie uogólnionych rozwiązań nielokalnych problemów dla quasiliniowych i nieliniowych równań różniczkowo-funkcyjnych cząstkowych pierwszego rzędu. Dowody twierdzeń bazują na metodzie bicharakterystyk i metodzie kolejnych przybliżeń.
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Numerical conditioning of delta-domain Lyapunov and Riccati equations
PublicationW pracy rozważono problem uwarunkowania dyskretno czasowych równań Lapunowa oraz równań Riccatiego - to znaczy problem wrażliwości rozwiązań takich równań na odchyłki ich parametrów od nominalnych wartości. Zdefiniowano odpowiedni "różniczkowy" wskaźnik uwarunkowania oraz podano efektywną metodę szacowania jego wartości. Udowodniono teoretycznie - a także przekonująco zilustrowano na drodze numerycznej - twierdzenie głoszące, iż...
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Quasilinearization methods for nonlinear parabolic equations with functional dependence
PublicationRozważamy problem Cauchy`ego dla nieliniowych równań parabolicznych z zależnością funkcyjną. Dowodzimy twierdzeń o szybkiej zbieżności ciągów kolejnych przybliżeń określonych w metodzie quasilinearyzacji w dwóch przypadkach: (i) argumentem funkcyjnym jest funkcja niewiadoma, (ii) zależność funkcyjna dotyczy również pochodnej funkcji niewiadomej.
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Quadrtic convergence of monotone iterations of differential-algebraic equations
PublicationZastosowano tu metodę quazilinearyzacji do równań różniczkowo-algebraicznych z warunkiem początkowym. Pokazano, że odpowiednie iteracje monotoniczne są zbieżne do jedynego rozwiązania.
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Second order differential equations with Dirichlet boundary conditions
PublicationZastosowano metodę kwazilinearyzacji aby wyznaczyć rozwiązanie przybliżone zagadnienia brzegowego dla równań różniczkowych rzędu drugiego. Pokazano kwadratową (lub prawie kwadratową) zbieżność tego rozwiązania do rozwiazania dokładnego.
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Implicit difference methods for parabolic functional differential equations.
PublicationPraca dotyczy przybliżania rozwiązań quasiliniowych parabolicznych równań różniczkowo-funkcyjnych za pomocą schematów różnicowych, uwikłanych ze względu na zmienną czasową. Wykonano pełną analizę zbieżności metod i pokazano na przykładzie, że nowe metody są istotnie lepsze od schematów jawnych. Dowód stabilności oparty jest na metodzie porównawczej z nieliniowymi oszacowaniami typu Perrona. Otrzymane wyniki można zastosować do...
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Differential equations with a singular matrix and convergence of approximate solutions
PublicationZastosowano metodę kwazilinearyzacji dla równań różniczkowych z macierzą osobliwą aby pokazać, że odpowiednie ciągi rozwiązań przybliżonych są kwadratowo zbieżne do rozwiązania naszego problemu.Metodę tę zastosowano do układów takich równań różniczkowych.
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Antiperiodic boundary value problems for functional differential equations
PublicationRównania różniczkowo funkcyjne z antyokresowymi warunkami brzegowymi są przedmiotem rozważań tej pracy. Podane zostały warunki dostateczne na istnienie jedynego rozwiązania, które jest granicą dwóch monotonicznych ciągów. Szybkość tej zbieżności jest również określona. Metoda dowodzenia oparta jest na metodzie kwasilinearyzacji. Otrzymano również pewne wyniki dotyczące problemów liniowych.
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Existence of solutions of differential equations with nonlinearmultipoint boundary conditions.
PublicationSformułowano warunki dostateczne na istnienie rozwiązań (jedynego lubekstremalnych) dla równań różniczkowych z warunkami jak wyżej przyzastosowaniu metody iteracji monotonicznych. O prawej stronie zagadnienia i nieliniowym warunku brzegowym zakładano między innymi, że spełniają jednostronny warunek Lipschitza.
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The Design Development of the Sliding Table Saw Towards Improving Its Dynamic Properties
PublicationCutting wood with circular saws is a popular machining operation in the woodworking and furniture industries. In the latter sliding table saws (panel saws) are commonly used for cutting of medium density fiberboards (MDF), high density fiberboards (HDF), laminate veneer lumber (LVL), plywood and chipboards of different structures. The most demanded requirements for machine tools are accuracy and precision, which mainly depend on...
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Active Dynamic Infrared Thermal Imaging in Burn Depth Evaluation
PublicationThe aim of this study was to find the relationship between active dynamic thermography (ADT) with cold excitation and burn depth. This new modality of evaluation of burns seems to be an attractive proposal for quantitative classification, allowing proper choice of burn wound treatment: conservative or surgical, especially compared with static thermography. The work was an in vivo experiment on domestic pigs, and a small number...
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Multistage Coupling of Eight Mistuned Bladed Disk on a Solid Shaft, Forced Vibration Analysis
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The investigations of influence of isotropic coupling betweenferrite coupled slot-lines on parameters of FSLS circulator
PublicationW pracy zaprezentowano badania cyrkulatora wykorzystującego magnesowaną wzdłużnie sekcję ferrytowych, sprzężonych linii szczelinowych (FSLS). Przedstawione badania oraz ich wyniki dotyczą wpływu wielkości sprzężenia izotropwego występującego pomiędzy sprzężonymi liniami szczelinowymi sekcji FSLS. Na podstawie uzyskanych wyników oraz weryfikacji ekperymentalnej stwierdzono, iż zapewnienie jak najniższej wartości sprzężenia izotropwego...
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Path planning algorithm for ship collisions avoidance in environment with changing strategy of dynamic obstacles
PublicationIn this paper a path planning algorithm for the ship collision avoidance is presented. Tested algorithm is used to determine close to optimal ship paths taking into account changing strategy of dynamic obstacles. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of evolutionary algorithm and based on it dedicated application...
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The Use of Unmanned Surface Vessels in Bathymetric Measurements of Waterbodies with Highly Dynamic Seafloor Relief
PublicationThe early 21st century is a time when unmanned surface vessels (USV) are used in various measurement applications. Modern autonomous and unmanned vessels are increasingly often used in bathymetric measurements whose aim is to measure the seafloor with the sufficient positioning accuracy. Therefore, the use of USVs in hydrography can be seen as the beginning of a new era in this regard. This paper presents bathymetric measurements...
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Modeling of wood frame structures with different insulation materials under damaging dynamic loading
PublicationWood frame buildings are very popular in regions that are exposed to different dynamic excitations, such as damaging earthquakes. Their seismic resistance is really important in order to prevent structural damages and human losses. This paper presents the results of advanced numerical investigation carried out using the FEM. Based on the models of wall panels, the numerical model of real structure of the wood frame building has...
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Parametric versus nonparametric modelling of dynamic susceptibility contrast enhanced MRI based data
PublicationDynamic tracking of a bolus of a paramagnetic agent (dynamic susceptibility contract - DSC) in MRI (magnetic resonance imaging) measurements is successfully used for assessment of the tissue perfusion and the other features and functions of the brain (i.e. cerebral blood flow - CBF, cerebral blood volume - CBV, mean transit time - MTT). The parametric and nonparametric approaches to the identification of MRI models are presented...
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublicationAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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THIRD-ORDER EXPONENTIAL INTEGRATOR FOR LINEAR KLEIN–GORDON EQUATIONS WITH TIME AND SPACE-DEPENDANT MASS
PublicationAllowing for space- and time-dependance of mass in Klein–Gordon equations re- solves the problem of negative probability density and of violation of Lorenz covariance of interaction in quantum mechanics. Moreover it extends their applicability to the domain of quantum cosmology, where the variation in mass may be accompanied by high oscillations....
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Forced vibrations in a dynamic system that is damped by a mechanism that trans-pass through its singular position
PublicationIn the paper, vibrations of a hybrid multibody-continuous system are investigated. For all the mechanical devices, effective damping methods are crucial in the design process. To obtain it, installation of viscous dampers or elasto-viscous elements is dominant. In the paper, an alternative method is investigated. It is based on modal disparity. To describe the method briefly, when structural damping is present in continuous systems,...
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Dynamic Headspace Sampling as an Initial Step for Sample Preparation in Chromatographic Analysis
PublicationThis work represents a brief summary of the use of dynamic headspace (DHS) as a technique for sample preparation in chromatographic analysis. Despite numerous developments in the area of analyte isolation and enrichment, DHS remains one of the fundamental methods used with GC. In our opinion, interest in this technique will not diminish significantly because it conforms to stipulations of green analytical chemistry. Moreover, DHS...
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Karol Grębowski dr inż.
PeopleKarol Grębowski (M.Sc.) works as an assistant at the Department of Technical Fundamentals of Architecture Design of the Faculty of Architecture at Gdansk University of Technology. His scientific research deals with dynamic phenomena occurring during the vibration of structures, bridges, and studies the design methodology of the elements forming passive protection system of the vehicles degraded by struck or explosion in the context...
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Recent Achievements in Constitutive Equations of Laminates and Functionally Graded Structures Formulated in the Resultant Nonlinear Shell Theory
PublicationThe development of constitutive equations formulated in the resultant nonlinear shell theory is presented. The specific features of the present shell theory are drilling rotation naturally included in the formulation and asymmetric measures of strains and stress resultants. The special attention in the chapter is given to recent achievements: progressive failure analysis of laminated shells and elastoplastic constitutive relation...
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DYNAMIC ANALYSIS OF THE IMPACT OF VIBRATION ON HISTORICAL BUILDINGS - AN OWN PROJECT OF EXTERNAL STAIRCASE
PublicationThis article presents numerical simulations that concern modeling of interaction of the external staircase’s construction with the observation deck on historic water tower located at Gdansk University of Technology. The interaction occurring according to various methods of the staircase's construction support on the wall of the historic tower was compared. The external staircase that allows for entering onto the monument was subjected...
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Very accurate time propagation of coupled Schrödinger equations for femto- and attosecond physics and chemistry, with C++ source code
PublicationIn this article, I present a very fast and high-precision (up to 33 decimal places) C++ implementation of the semi-global time propagation algorithm for a system of coupled Schrödinger equations with a time-dependent Hamiltonian. It can be used to describe time-dependent processes in molecular systems after excitation by femto- and attosecond laser pulses. It also works with an arbitrary user supplied Hamiltonian and can be used...
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Fading Characteristics for Dynamic Body-to-Body Channels in Indoor and Outdoor Environments
PublicationThis paper presents an analysis of the fading characteristics in dynamic body-to-body channels, based on measurements performed at 2.45 GHz in indoor and outdoor environments. The statistical analysis of the small- and large-scale fading shows that the Nakagami Distribution is the best model for the former and the Log-Normal one for the latter. An important influence of body shadowing...
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Experimental dynamic study on a timber-frame house using shaking table
PublicationThe aim of this paper is to show the results of the shaking table experimental study concerning the behaviour of the model of the timber-frame house under earthquake excitation and impact loading. In order to determine the basic dynamic properties of the undamaged structure, the free vibration and the sweep-sine tests were first conducted. Then, the model was excited using the time history record of the El Centro earthquake of...
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Dynamic analysis of temporary steel grandstand subjected to human-induced excitations due to jumping
PublicationSteel grandstands are structures that are frequently used during sport games and many other non-sporting events, such as festivals, music concerts, or even politicians rallies, with participation of a large number of attendees. Unfortunately, the presence of unexpected excessive dynamic loads due to unpredictable behaviour of spectators (e.g. synchronized harmonic jumping or swaying) may lead to...
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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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Identification of dynamic parameters in the context of diagnostics of steel tank with different level of liquid.
PublicationThe paper presents an experimental study to identify the dynamic parameters of a water-filled tank model. The experimental modal analysis approach involving the excitation at one point of the structure and acquisition of vibra tions at selected points distri buted over the tank surface allowed to determine the resonance frequencies, mode shapes and damping ratios. The main aim of the research was to examine the influence of...
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Comparison of properties of the new electro-mechanical model and circumferential model of the inductive-dynamic drive
PublicationThe article presents a new electromechanical model of inductive-dynamic drive. The model is implemented in two environments: Maxwell for analyzing electrodynamic phenomena including moving of the disc and Ansys which allows for stress analysis on the basis of the volume forces imported from Maxwell. Additionally, a model validation by comparing with the existing circumferential model was carried out.
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Development Of Dynamic Method For Evaluation Of Corrosion Rate On The Example Of Organic Corrosion İnhibitor
PublicationMeasurements of the corrosion rate belong to the most important aspects of materials science. In order to reduce material loss corrosion inhibitors are used. However selection of proper inhibitor should be based on evaluation of its mechanism and effective concentrations. Mechanism of inhibition usually has dynamic character so physicochemical parameters are changing in time. Most of actually used methods...
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Dynamic Charging of Electric Buses as a Way to Reduce Investment Risks of Urban Transport System Electrification
PublicationNight charging and fast charging are currently the two most common systems for charging electric buses. Despite the fact that numerous trial installations were started, neither of these two systems has obtained unqualified approval of the users. The alternative is to charge vehicles in motion - dynamic charging which combines the advantages of trolleybus transport and of electric buses. One of the advantages is the reduction of...
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Novel application of dynamic electrochemical impedance monitoring to a cataphoretic coating process
PublicationThe paper presents a novel method of on-line impedance monitoring of cataphoretic coating application process. Utilization of dynamic electrochemical impedance spectroscopy (DEIS) overcame the fundamental problem connected with non-stationarity of the aforementioned coating deposition process, which eliminates classical impedance spectroscopy technique from a real-time description of cataphoresis. The paper illustrates selected examples...
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DYNAMIC ANALYSIS OF HISTORIC RAILWAY BRIDGES IN POLAND IN THE CONTEXT OF ADJUSTING THEM TO PENDOLINO TRAINS
PublicationThe article presents the dynamic analysis of the historic railway bridge in Tczew as an example of the usefulness of such type of bridge for high-speed trains. The model of the bridge and the simulation of rolling stock passage was performed in SOFISTIK program. The scope of work includes experimental studies, the solution of the problem concerning the correct solution features dynamic model takes into account the dependencies...
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Numerical analysis by FEM and analytical study of the dynamic thermal behavior of hollow bricks with different cavity concentration
PublicationThis paper presents the investigation results on the influence of the cavity concentration in hollow bricks on static and dynamic thermal parameters: a time lag, a decrement factor, an equivalent thermal diffusivity (ETD) and an equivalent thermal conductivity (ETC). The dynamic thermal behavior of hollow bricks is studied with an optimized cavity shape to reduce the intensity of radiation and convective heat exchange. The thermal...
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Numerical analysis by FEM and analytical study of the dynamic thermal behavior of hollow bricks with different cavity concentration
PublicationThis paper presents the investigation results on the influence of the cavity concentration in hollow bricks on static and dynamic thermal parameters: a time lag, a decrement factor, an equivalent thermal diffusivity (ETD) and an equivalent thermal conductivity (ETC). The dynamic thermal behavior of hollow bricks is studied with an optimized cavity shape to reduce the intensity of radiation and convective heat exchange. The thermal...
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Approximation of Fractional Order Dynamic Systems Using Elman, GRU and LSTM Neural Networks
PublicationIn the paper, authors explore the possibility of using the recurrent neural networks (RNN) - Elman, GRU and LSTM - for an approximation of the solution of the fractional-orders differential equations. The RNN network parameters are estimated via optimisation with the second order L-BFGS algorithm. It is done based on data from four systems: simple first and second fractional order LTI systems, a system of fractional-order point...
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Dynamic Execution of Engineering Processes in Cyber-Physical Systems of Systems Toolchains
PublicationEngineering tools support the process of creating, operating, maintaining, and evolving systems throughout their lifecycle. Toolchains are sequences of tools that build on each others' output during this procedure. The complete chain of tools itself may not even be recognized by the humans who utilize them, people may just recognize the right tool being used at the right place in time. Modern engineering processes, however, do...
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Closed Form Constraint Equations Used to Express Frictionless Slip of Multibody Systems Attached to Finite Elements—Application to a Contact between a Double Pendulum and a Beam
PublicationThis paper focuses on the numerical modeling of the dynamics of mechanical systems. Robots that can inspect high-voltage lines inspired this research. Their control systems must anticipate potential grab positions appropriately. We intend to formulate equations dedicated to the numerical description of the robot/cable contact. The investigated problem is not straightforward, since parts of the modeled systems are numerically inhomogeneous....
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Dynamic variables limitation for backstepping control of induction machine and voltage source converter
PublicationDynamic variables limitation for backstepping control of induction machine and voltage source converter The paper presents the method of control of an induction squirrel-cage machine supplied by a voltage source converter. The presented idea is based on an innovative method of the voltage source converter control, consisting in direct joining of the motor control system with the voltage source rectifier control system. The combined...
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Development and application of asphalt binder relaxation test in different dynamic shear rheometers
PublicationIn this study, a novel relaxation test is proposed to evaluate asphalt binder low temperature properties using a Dynamic Shear Rheometer (DSR) with parallel plates of 4 mm in diameter. Three rheometers from three different manufacturers are used to analyze seven asphalt binders. Different material parameters are derived which are useful to evaluate and discriminate different asphalt binders. Test results of all three instruments...
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Ship weather routing optimization with dynamic constraints based on reliable synchronous roll prediction
PublicationShip routing process taking into account weather conditions is a constrained multi-objective optimization problem and it should consider various optimization criteria and constraints. Formulation of a stability-related, dynamic route optimization constraint is presented in this paper. One of the key objectives of a cross ocean sailing is finding a compromise between ship safety and economics of operation. This compromise should...
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Dynamic impedance data for various carboxylic acids corrosion inhibition of aluminium in alkaline media (pH=11)
Open Research DataThis dataset contains the results of Dynamic Electrochemical Impedance Spectroscopy (DEIS) carried out in galvanostatic mode under iDC=0, carried out in order to define the corrosion inhibition effect of various studied carboxylic acids: citric acid, malic acid, maleic acid, succinic acid, tartaric acid, carballylic acid, and serine. The experiment...
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Mutual Coupling Between IFF/SSR Microstrip Antennas with Reduced Transversal Size- Experimental Study
PublicationW artykule opisano wyniki symulacji oraz pomiarów sprzężeń wzajemnych anten systemu IFF. Wyniki poprzedza analiza konfiguracji i działania pojedynczej anteny zasilanej szczeliną typu H. Badania przeprowadzono dla szyku poziomego i pionowego, w zakresie wejściowego współczynnika odbicia oraz współczynnika sprzężenia na dwóch częstotliwościach pasma IFF.
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Prognosis after acute coronary syndrome in relation with ventricular–arterial coupling and left ventricular strain
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Aryl and N-arylamide carbon nanotubes for electrical coupling of laccase to electrodes in biofuel cells and biobatteries
PublicationSingle walled carbon nanotubes (SWCNTs) were equipped with aryl residues by chemical reactions. These insoluble materials were used to substitute classical soluble mediators, which help to transfer electrical charge between the conducting electrode and the redox active center of enzyme molecules. The effect of different aryl residues on the efficiency of the catalytic reduction of dioxygen in the presence of laccase was systematically...
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Adaptive resolution simulation of liquid para-hydrogen: testing the robustness of the quantum-classical adaptive coupling
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Classical to Path-Integral Adaptive Resolution in Molecular Simulation: Towards a Smooth Quantum-Classical Coupling
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