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Search results for: DYNAMIC IN VITRO DISSOLUTION
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Modified nanodiamond particle size studies by means of dynamic light scattering technique
PublicationThe Methods Utilizing the Phenomena of Light Scattering to Measure Particle Size distribution in different solvent, such as deionise water and alcohol and also to study the various structural formation when nanodiamond solution is placed on silicon surface. The purpose of this research project is divided into two parts to configure the measurement units for examining modified nanodiamond particles, examination...
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Research on the effect of low-sulphur marine fuels on the dynamic characteristics of a CI engine
PublicationThe implementation of low-sulphur, so-called modified marine fuels into operation requires prior labora- tory engine tests to assess the energy, emission and structural effects of their usage. This type of research are carried out on the test bed of a diesel engine as a small-scale physical model that reproduces the adequate design and process (parametric) features of a full-size marine engine. Their key stage is to determine the energy...
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Extraction and evaluation of gas-flow-dependent features from dynamic measurements of gas sensors array
PublicationGas analyzers based on gas sensors are the devices which enable recognition of various kinds of volatile compounds. They have continuously been developed and investigated for over three decades, however there are still limitations which slow down the implementation of those devices in many applications. For example, the main drawbacks are the lack of selectivity, sensitivity...
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Evaluation of Temperature Influence on Electrochemical Processes Occurring in a Lithium-Ion Supercapacitor with the Use of Dynamic Electrochemical Impedance Spectroscopy
PublicationIn order to obtain the full impedance characteristics of a lithium-ion capacitor as a function of temperature, the authors proposed the use of dynamic electrochemical impedance spectroscopy. Impedance tests were carried out under wide range of dynamic temperature changes for lithium-ion supercapacitors. Significant differences in electrochemical processes were observed as a result of working temperature. Moreover, the quality of...
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The dynamic performance analysis of the Micro-turbine's rotor supparted on slide and roling element bearings
PublicationThis article presents the results of investigations of dynamic characteristics of a small-dimension rotor with slide and rolling element bearings. The object of investigations was the rotor-bearing system designed for the ORC based low-power steam micro-turbine. The investigations were performed using MESWIR series programs, as well as commercial FEA software ABAQUS and MADYN 2000. The results of modal analysis of the micro-rotor...
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Dynamic polarizability of the relativistic hydrogenlike atom: Application of the Sturmian expansion of the Dirac-Coulomb Green function
PublicationWe utilize the Sturmian expansion of the Dirac-Coulomb Green function [R. Szmytkowski, J. Phys. B 30, 825 (1997)] to obtain components of the dynamic dipole polarizability tensor of the relativistic hydrogenlike atom in the ground state. It is found that the tensor may be expressed in terms of two independent quantities: a scalar polarizability and a vector polarizability, the latter being of the relativistic origin. In the static...
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Numerical investigation on dynamic performance of a multi-storey steel structure model and comparison with experimental results
PublicationShaking table testing is the most commonly adopted method to simulate earthquake forces. This approach allows us to analyze the dynamic performance and provides a valuable insight into the dynamics of building structures, which helps to improve their future safety and reliability. The present study aims to conduct a numerical evaluation of dynamic response of a multi-storey steel structure model, which was previously examined during...
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Numerical Investigation on Dynamic Performance of a Multi-storey Steel Structure Model and Comparison with Experimental Results
PublicationShaking table testing is the most commonly adopted method to simulate earthquake forces. This approach allows us to analyze the dynamic performance and provides a valuable insight into the dynamics of building structures, which helps to improve their future safety and reliability. The present study aims to conduct a numerical evaluation of dynamic response of a multi-storey steel structure model, which was previously examined during...
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NUMERICAL SIMULATION OF CRATER CREATING PROCESS IN DYNAMIC REPLACEMENT METHOD BY SMOOTH PARTICLE HYDRODYNAMICS
PublicationA theoretical base of SPH method, including the governing equations, discussion of importance of the smoothing function length, contact formulation, boundary treatment and finally utilization in hydrocode simulations are presented. An application of SPH to a real case of large penetrations (crater creating) into the soil caused by falling mass in Dynamic Replacement Method is discussed. An influence of particles spacing on method...
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STUDY OF ARRAY OF MEMS INERTIAL MEASUREMENT UNITS UNDER QUASI-STATIONARY AND DYNAMIC CONDITIONS
PublicationA measurement system includes all components in a chain of hardware and software that leads from a measured variable to processed data. In that context, the type and quality of the sensors or measuring devices are critical to any measurement system. MEMS/IMU sensors lag behind leading technologies in this respect, but the MEMS/IMU performance rapidly changes while is relatively inexpensive. For this reason, the paper proposes...
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A higher order transversely deformable shell-type spectral finite element for dynamic analysis of isotropic structures
PublicationThis paper deals with certain aspects related to the dynamic behaviour of isotropic shell-like structures analysed by the use of a higher order transversely deformable shell-type spectral finite element newly formulated and the approach known as the Time-domain Spectral Finite Element Method (TD-SFEM). Although recently this spectral approach is reported in the literature as a very powerful numerical tool used to solve various...
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Adaptive Optimal Discrete-Time Output-Feedback Using an Internal Model Principle and Adaptive Dynamic Programming
PublicationIn order to address the output feedback issue for linear discrete-time systems, this work suggests a brand-new adaptive dynamic programming (ADP) technique based on the internal model principle (IMP). The proposed method, termed as IMP-ADP, does not require complete state feedback, merely the measurement of input and output data. More specifically, based on the IMP, the output control problem can first be converted into a stabilization...
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Robust Parameter Estimation and Output Prediction for Reactive Carrier-Load Nonlinear Dynamic Networks
PublicationIn this paper an extension of on-line model simplification technique for a class of networked systems, namely reactive carrier-load nonlinear dynamic networked system (RCLNDNS), kept within point-parametric model (PPM) framework is addressed. The PPM is utilised to acquire a piece wise constant time-varying parameter linear structure for the RCLNDNS suitable for the on-line one step ahead prediction that may be applied to monitoring...
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The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
PublicationHydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm....
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Study of Direct Methanol Fuel Cell Process Dynamics Using Dynamic Electrochemical Impedance Spectroscopy
PublicationA new technique, which was developed to characterize the direct methanol fuel cell under work conditions, has been presented in this paper. The impedance measurements were made using dynamic electrochemical impedance spectroscopy research technique in the galvanostatic mode, using multiple sinusoidal excitation. Obtained results show, that together with an increase of the temperature and working load, the global impedance...
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DYNAMIC MECHANICAL BEHAVIOUR OF GFRP COMPOSITES WITH SiO2 NANO PARTICLES REINFORCED EPOXY MATRIX
PublicationDynamic mechanic (DMA) tests were performed to compare the mechanical behaviour of glass fibre reinforced epoxy laminate composites with SiO2 nanoparticle reinforced matrix. The selection of the most promising nanoparticle concentrations was considered in terms of elastic modulus and glass transition temperature. The reference specimens (0% nanoparticles) did not contain diluent accordingly the results do not allow the exact comparison...
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Dynamic impedance measurements of the Direct Methanol Fuel Cell cathode at various operating temperatures
PublicationThis article discusses the application of impedance analysis for diagnosing the cathode of a direct methanol fuel cell at various operating temperatures. The Dynamic Electrochemical Impedance Spectroscopy technique coupled with a linear current scan was applied for this purpose. This technique allowed the observation of changes in the cathode's properties in the fuel cell operating under real working conditions. An equivalent model...
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The early failure of the gamma nail and the dynamic hip screw in femurs with a wide medullary canal. A biomechanical study of intertrochanteric fractures
PublicationBackground: Intertrochanteric fractures may occur in a bone with a wide medullary canal that may lead to significant mobility of a intramedullary nail, contrary to an extramedullary device. This study evaluates the Dynamic Hip Screw and the gamma nail in AO 31.A2.1 fractures in these circumstances. Methods: Synthetic femora with canals drilled to 18 mm were used. Five fixation types were examined: a 2 - hole and a 4 – hole Dynamic...
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Do global brands contribute to the economy of their country of origin? A dynamic spatial approach
PublicationPurpose - Brand positioning based on the brand’s country of origin is at the centre of attention in international marketing. It is evident that global brands constitute critical intangible assets for businesses and places. However, it is not clear how they contribute to national economies. This paper aims to discuss the significance of brands as contributing to the value of their companies but also helping to leverage national...
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Static and Dynamic Mechanical Properties of 3D Printed ABS as a Function of Raster Angle
PublicationDue to the rapid growth of 3D printing popularity, including fused deposition modeling (FDM), as one of the most common technologies, the proper understanding of the process and influence of its parameters on resulting products is crucial for its development. One of the most crucial parameters of FDM printing is the raster angle and mutual arrangement of the following filament layers. Presented research work aims to evaluate different...
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Prediction of Overall In Vitro Microsomal Stability of Drug Candidates Based on Molecular Modeling and Support Vector Machines. Case Study of Novel Arylpiperazines Derivatives
PublicationOther than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model...
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Novel Nystatin A1 derivatives exhibiting low host cell toxicity and antifungal activity in an in vitro model of oral candidosis
PublicationOpportunistic oral infections caused by Candida albicans are frequent problems in immunocompromised patients. Management of such infections is limited due to the low number of antifungal drugs available, their relatively high toxicity and the emergence of antifungal resistance. Given these issues, our investigations have focused on novel derivatives of the antifungal antibiotic Nystatin A1, generated by modifications at the amino...
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Data fusion of GPS sensors using Particle Kalman Filter for ship dynamic positioning system
PublicationDepending on standards and class, dynamically positioned ships make use of different numbers of redundant sensors to determine current ship position. The paper presents a multi-sensor data fusion algorithm for the dynamic positioning system which allows it to record the proper signal from a number of sensors (GPS receivers). In the research, the Particle Kalman Filter with data fusion was used to estimate the position of the vessel....
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Validity of impedance spectra obtained by dynamic electrochemical impedance spectroscopy verified by Kramers-Kronig transformation.
PublicationArtykuł przedstawia weryfikację wiarygodności widm impedancyjnych otrzymanych za pomocą niedawno wprowadzonej techniki eksperymentalnej - Dynamicznej Elektrochemicznej Spektroskopii Impedancyjnej (Dynamic Electrochemical Impedance Spectroscopy, DEIS). Technika ta zakłada, że badany system jest pseudostacjonarny jeśli czas pomiaru jest odpowiednio krótki. Czas potrzebny na otrzymanie pojedynczego spektrum zależy od długości okna...
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Simplified approach to assess the dynamic response of a container ship subjected to bow slamming load
PublicationSimplified approach to assess the dynamic response of a container ship subjected to the bow slamming load, resulting in a transient vibratory response, typically called a 'whip-ping', is presented. The accurate numerical modelling is very complex and involves cou-pling of the hydrodynamic and structural solution at every time step, leading to huge com-putational and workload cost. Thus, the one-way coupling methodology is adopted,...
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Primary role identification in dynamic social networks
PublicationIdentyfikacja ról w sieci społecznej jest jednym z podstawowych zagadnień analizy takich sieci. W artykule przedstawiamy nowe podejście do tego zagadnienia. Pokazujemy w jaki sposób można dokonać identyfikacji ról poprzez wykorzystanie zaproponowanego modelu zachowań aktorów. Model taki tworzą podgrafy wzorcowe oraz diagramy stanów okreslające sekwencje aktywności w zachowaniu aktorów. Na bazie wyznaczonych modeli zachowań oraz...
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The influence of carbon dioxide on dynamic thermography results
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Implementation of Active Dynamic Thermography in medical diagnostics
PublicationW pracy przedstawiono wyniki badań wdrożeniowych Aktywnej Termografii Dynamicznej w diagnostyce wybranych chorób.
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Static and dynamic analysis of thin-walled frames
PublicationW pracy przedstawiono model ramy zbudowanej z elementów cienkościennych o przekrojach otwartych stosowany w analizie statycznej i dynamicznej za pomocą metody elemntów skończonych. Model składa się z elementów opisanych teorią prętów cienkościennych o przekrojach nieodkształcalnych oraz superelementów węzłowych. Proponowany model pozwala na ujęcie w analizie efektów bimomentowych oraz deformacji konstrukcji w miejscach lokalizacji...
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Test Stand for Metamaterials Dynamic Properties Examination
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Fading modelling in dynamic off-body channels
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Polish experience of dynamic tests for bored piles
PublicationPrzedstawiono zastosowanie badań dynamicznych, DLT, do oceny nośności wierconych pali wielkośrednicowych.Na podstawie badań terenowych, dla dwóch obiektów mostowych, wykonano badania dynamiczne (DLT) oraz korelacyjne badania statyczne (ASPLT). Określono pełną krzywą osiadania. Uzyskano dobrą zgodność krzywych obciążenie - osiadanie dla zakresu obciążeń roboczych.
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A novel dynamic noise maps visualization tool
PublicationW referacie przedstawiono aplikację realizujacą wizualizację dynamicznych map akustycznych zintegrowaną z multimedialnym systemem monitoringu hałasu. Moduł ten został oparty na nowym podejściu do wykreślania dynamicznych map, w referacie przedstawiono porównanie wyników uzyskanych metodami tradycyjnymi i zaproponowaną metodą. Słowa kluczowe: dynamiczne mapy, wizualizacja, monitoring, hałas, system GIS
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The dynamic thermal properties of aerogel-incorporated concretes
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Dynamic effects during emptying of large silos.
PublicationPublikacja obejmuje zagadnienie rezonansowych efektów dynamicznych występujących podczas opróżniania silosów zawierających materiały sypkie
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Dynamic Perfect hashing with finite-state automata
PublicationMinimalna doskonała funkcja mieszająca dostarcza odwzorowania zbioru n niepowtarzalnych słów w zwarty zakres n liczb całkowitych. Gdy jest realizowane za pomocą automatów skończonych, odwzorowanie wynika z porządku słów (zwykle alfabetycznego) w zbiorze. Dodanie nowych słów zmieniłoby porządek słów rozpoznawanych przez automat, zmieniając całe odwzorowanie i czyniąc je bezużytecznym w wielu dziedzinach. Dlatego nazywamy je statycznym....
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A Concept of Mechatronic design for a Surveillance of Dynamic Systems
PublicationW publikacji przedstawiono zastosowanie koncepcji projektowania mechatronicznego w nadzorowaniu systmów dynamicznych. W szczególności są to aktywne nadzorowanie drgań podczas frezowania oraz nadzorowanie ruchu platformy 3-kołowej. Przy tworzeniu opisywanych rozwiązań zastosowano techniki projektowania wirtualnego, symulacjje komputerowe jaki w technice Hardware-in-the-Loop. W pracy zamieszczono także przykładowe wyniki badań eksperymentalnych...
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Fading Modelling in Dynamic Off-Body Channels
PublicationThis paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components,...
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Vibration surveillance of dynamic systems and production processes
PublicationPraca dotyczy poszukiwania sposobów minimalizacji poziomu drgań podczas pracy maszyn i urządzeń wykonujących określone procesy robocze. Do modelowania dyskretnego wykorzystano metodę elementów skończonych. Rozważano dynamikę niestacjonarnego dyskretnego układu sterowanego, którego zachowanie opisano we współrzędnych uogólnionych, jak również - układu hybrydowego. Ten ostatni uzyskano dzięki wyodrębnieniu z całości podukładu stacjonarnego,...
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Dynamic mechanical properties and flexing fatigue resistance of tire sidewall rubber as function of waste tire rubber reclaiming degree
PublicationA stepwise downsizing method of gel particles in reclaimed rubber to a micro-nano scale and its excellent dynamic performance in tire sidewall were introduced by this work. The results showed that the size of gel particles decreased from several micrometers to micro-nanometers with the increase of reclaiming degree, accompanied by reduced molecular weight and widened molecular weight distribution of sol fraction. The addition of...
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On Dynamic Boundary Conditions Within the Linear Steigmann-Ogden Model of Surface Elasticity and Strain Gradient Elasticity
PublicationWithin the strain gradient elasticity we discuss the dynamic boundary conditions taking into account surface stresses described by the Steigmann–Ogden model. The variational approach is applied with the use of the least action functional. The functional is represented as a sum of surface and volume integrals. The surface strain and kinetic energy densities are introduced. The Toupin–Mindlin formulation of the strain gradient elasticity...
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Effect of oxidation and in vitro intestinal hydrolysis on phospholipid toxicity towards HT29 cell line serving as a model of human intestinal epithelium
PublicationOxidation of food-derived phospholipids (PLs) can influence nutrient digestion and induce oxidative stress in gastrointestinal epithelium. In this study, hen egg yolk PL fraction was used to evaluate the effect of lipoxygenase (LOX)-induced PL oxidation on the rate of PL hydrolysis catalyzed by pancreatic phospholipase A2 (PLA2) in the presence of bile salts (BSs). Then, PL/BS solutions containing native or oxidized PLs were used...
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Formulation, characterisation and in vitro studies of doxorubicin-loaded silica–polydimethylsiloxane granules
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Synthesis and in vitro characterization of freeze-dried doxorubicin-loaded silica xerogels
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Biological and mechanical properties of bone cement with nanoparticles - in vivo and in vitro research
PublicationDespite antibiotics preventive treatment, before and after an implant implementation, risk of infection are real. These infections at the implant surface develop in a few months after applying them into the body. To prevent the development of bacteria and to reduce the risk of infection, implants coated with nanoparticles come into use. The Mechanical Department of the Technical University of Gdańsk carried out a research with...
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Size-Dependent in Vitro Biocompatibility and Uptake Process of Polymeric Carbon Nitride
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In vitro and in vivo biological activities of azulene derivatives with potential applications in medicine
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Agomelatine's antiglycoxidative action—In vitro and in silico research and systematic literature review
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Biodegradable macromolecular conjugates of citropin: Synthesis, characterization and in vitro efficiency study
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Protective effect of desloratadine against oxidative stress in human erythrocytes in vitro
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