Search results for: SIMULATION STUDY
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The Effect of Sterols on Amphotericin B Self-Aggregation in a Lipid Bilayer as Revealed by Free Energy Simulations
PublicationAmphotericin B (AmB) is an effective but toxic antifungal drug, known to increase the permeability of the cell membrane, presumably by assembling into transmembrane pores in a sterol-dependent manner. The aggregation of AmB molecules in a phospholipid bilayer is, thus, crucial for the drug’s activity. To provide an insight into the molecular nature of this process, here, we report an atomistic molecular dynamics simulation study...
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A Model-Based Improved Control of Dissolved Oxygen Concentration in Sequencing Wastewater Batch Reactor
PublicationBiochemical processes at wastewater treatment plant are complex, nonlinear, time varying and multivariable. Moreover, relationships between processes are very strong. One of the most important issues is exerting proper control over dissolved oxygen levels during nitrification phase. This parameter has a very large impact on activity of microorganisms in activated sludge and on quality of pollution removal processes. Oxygen is supplied...
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Analytical predictions for the buckling of a nanoplate subjected to non-uniform compression based on the four-variable plate theory
PublicationIn the present study, the buckling analysis of the rectangular nanoplate under biaxial non-uniform compression using the modified couple stress continuum theory with various boundary conditions has been considered. The simplified first order shear deformation theory (S-FSDT) has been employed and the governing differential equations have been obtained using the Hamilton’s principle. An analytical approach has been applied to obtain...
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The literature review on boundary conditions of use for non-residential buildings
PublicationThis paper describes the results of qualitative and quantitative literature reviews on boundary conditions within educational buildings, emphasising the users' perspective. The reviews were performed before and during the COVID-19 pandemic using Scopus, Taylor& Francis, Web of Science databases. The boundary conditions understood as special characteristics for use and or precondition, determining specific features of buildings...
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The literature review on boundary conditions of use for non-residential buildings. Educational buildings.
PublicationThis paper describes the results of qualitative and quantitative literature reviews on boundary conditions within educational buildings, emphasising the users' perspective. The studies were performed before and during the COVID-19 pandemic using Scopus, Taylor& Francis, and Web of Science databases. The boundary conditions are understood as special characteristics for use and or precondition, determining specific features of...
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Practical Eco-Driving Strategy for Suburban Electric Multiple Unit
PublicationIn this paper, a practical approach to velocity profile optimization for electric multiple unit was presented. The study focuses on a case of fast urban railway, which is a popular mean of transport across Tricity, Poland. Based on observations and measurements, a potential for improvement of energy efficiency by modifying the speed profile was recognized. In order to conduct necessary calculations, simulation model of railway...
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Rapid design of miniaturised branch-line couplers through concurrent cell optimisation and surrogate-assisted fine-tuning
PublicationIn this study, the authors introduce a methodology for low-cost simulation-driven design optimisation of highly miniaturised branch-line couplers (BLCs). The first stage of their design approach exploits fast concurrent optimisation of geometrically dependent, but electromagnetically isolated cells that constitute a BLC. The cross-coupling effects between the cells are taken into account in the second stage, where a surrogate-assisted...
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Experimental and numerical analysis of the modified TB32 crash tests of the cable barrier system
PublicationRoad restraint systems, including safety barriers, are one of the means used to improve road safety. Currently, they can be allowed to general use after passing the specific crash tests. However, it is always important and desirable to evaluate their performance under various realistic conditions, which can happen on the roads. In this study, the behaviour of the cable barrier system in impact conditions different than assumed...
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Evaluation of fire hazard in electrical installations due to unfavorable ambient thermal conditions
PublicationEvaluation of fire hazard caused by electrical installations is a difficult and important topic, and it limits the possibility of loss of life or health of people, as well as the occurrence of significant property damage. In particular, this hazard was caused by power cables and especially photovoltaic (PV) installations. The authors proved that power cables directly exposed to strong solar radiation are likely to exceed maximum...
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Geminate-pair dissociation yield in systems with exponential energetic disorder — A Monte Carlo study
PublicationGeminate electron–hole recombination in systems with exponential energetic disorder is studied by Monte Carlo method. The field and temperature dependencies of geminate-pair dissociation probability are calculated. It is established that the dissociation yield of carrier pairs depends mainly on the extent of carrier thermalization, which influences the Einstein relationship. The approximate limiting temperature is given by Te =...
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Adaptacja akustyczna pomieszczenia wykładowego - studium przypadku
PublicationW niniejszej pracy przedstawiono analizę rozkładu pola akustycznego sali wykładowej znajdującej się w budynku Wydziału Elektroniki i Telekomunikacji Politechniki Gdańskiej. Badania przeprowadzono metodą pomiarową oraz symulacyjną z wykorzystaniem programu Odeon. Wybór parametrów oceny akustyki wnętrz sugerowany jest wymaganiami stawianymi pomieszczeniom lekcyjnym z zaznaczeniem multimedialnego charakteru wykładów prowadzonych...
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Improved maximum power point tracking algorithms by using numerical analysis techniques for photovoltaic systems
PublicationSolar photovoltaic (PV) panels generate optimal electricity when operating at the maximum power point (MPP). This study introduces a novel MPP tracking algorithm that leverages the numerical prowess of the predictor-corrector method, tailored to accommodate voltage and current fluctuations in PV panels resulting from variable environmental factors like solar irradiation and temperature. This paper delves into the intricate dynamics...
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Modelling of Abdominal Wall Under Uncertainty of Material Properties
PublicationThe paper concerns abdominal wall modelling. The accurate prediction and simulation of abdominal wall mechanics are important in the context of optimization of ventral hernia repair. The shell Finite Element model is considered, as the one which can be used in patient-specific approach due to relatively easy geometry generation. However, there are uncertainties in this issue, e.g. related to mechanical properties since the properties...
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Computer vision techniques applied for reconstruction of seafloor 3D images from side scan and synthetic aperture sonars data
PublicationThe Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled...
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Novel hierarchical nonlinear control algorithm to improve dissolved oxygen control in biological WWTP
PublicationWastewater treatment is a problem known to humankind for centuries. The quality of treated sewage determines the condition of reservoirs around the world. Control of such a complex and nonlinear system as a wastewater treatment plant requires thorough knowledge of the process. The paper presents a hierarchical control system of a Sequencing Batch Reactor (SBR) in Wastewater Treatment Plant (WWTP) taking into account a model based...
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Model of optical phantoms thermal response upon irradiation with 975 nm dermatological laser
PublicationWe have developed a numerical model describing the optical and thermal behavior of optical tissue phantoms upon laser irradiation. According to our previous studies, the phantoms can be used as substitute of real skin from the optical, as well as thermal point of view. However, the thermal parameters are not entirely similar to those of real tissues thus there is a need to develop mathematical model, describing the thermal and...
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DETERMINING THE TIME CONSTANT USING TWO METHODS AND DEFINING THE THERMOCOUPLE RESPONSE TO SINE EXCITATION OF GAS TEMPERATURE
PublicationThis paper describes the two methods of determining the time constant of type K thermocouple, for two construction solutions: the exposed weld and the mantle fillet weld. This is an important parameter indicating the response time of the thermocouple on the recorded signal. The first method consists of determining the value of τ in the way of numerical simulation of heat exchange between the thermocouple and the current of gas...
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Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublicationThe modern concept of a universal converter is intended as a power converter (PC) suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow easier integration of renewable energy sources and energy storage systems (ESSs), interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and...
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Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublicationThe modern concept of a universal converter is intended as a power converter suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow an easier integration of renewable energy sources and energy storage systems, interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications...
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Identification of defected sensors in an array of amperometric gas sensors
PublicationPurpose Amperometric gas sensors are commonly used in air quality monitoring in long-term measurements. Baseline shift of sensor responses and power failure may occur over time, which is an obstacle for reliable operation of the entire system. The purpose of this study is to check the possibility of using PCA method to detect defected samples, identify faulty sensor and correct the responses of the sensor identified as faulty. Design/methodology/approach In...
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Three-dimensional modeling and automatic analysis of the human nasal cavity and paranasal sinuses using the computational fluid dynamics method
PublicationPurpose The goal of this study was to develop a complete workflow allowing for conducting computational fluid dynam- ics (CFD) simulation of airflow through the upper airways based on computed tomography (CT) and cone-beam computed tomography (CBCT) studies of individual adult patients. Methods This study is based on CT images of 16 patients. Image processing and model generation of the human nasal cavity and paranasal sinuses...
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Investigation of mechanism of desmopressin binding in vasopressin V2 receptor versus vasopressin V1a and oxytocin receptors: Molecular dynamics simulation of the agonist-bound state in the membrane–aqueous system
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Impact of Propeller Emergence on Hull, Propeller, Engine, and Fuel Consumption Performance in Regular Head Waves
PublicationIn this study, the impact of propeller emergence on the performance of a ship (speed), propeller (thrust, torque, and RPM), a diesel engine (torque and RPM) and fuel consumption are analysed under severe sea conditions. The goal is to describe the variation in the system variables and fuel consumption rather than analysing the motion of the ship or the phenomenon of propeller ventilation in itself. A mathematical model of the...
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Parametric study of fluid flow and heat transfer over louvered fins of air heat pump evaporator
PublicationTwo-dimensional numerical investigations of the fluid flow and heat transfer have been carried out for the laminar flow of the louvered fin-plate heat exchanger, designed to work as an air-source heat pump evap- orator. The transferred heat and the pressure drop predicted by simulation have been compared with the corresponding experimental data taken from the literature. Two dimensional analyses of the louvered fins with varying...
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Experimental and numerical investigation of mercury removal from flue gas by sorbent polymer composite
PublicationThis paper presents an experimental and numerical investigation of the performance of a sorbent polymer composite (SPC) material used for removing mercury from the flue gases in a full-scale industrial installation. The investigated material is an attractive alternative to activated carbon, which is commonly used for this purpose. While the application of the SPC is characterized by high capital expenditures, this technology offers...
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Stochastic optimisation algorithm for optimisation of controller parameters for control of dissolved oxygen in wastewater treatment plant
PublicationWastewater treatment plants (WWTPs) are very important facilities for mankind. They enable the removal and neutralisation of man-made pollutants. Therefore, it is important for wastewater treatment plants to operate as efficiently as possible so that the level of pollutants in the treated wastewater meets specific requirements. This paper concerns the design of a hierarchical nonlinear adaptive control system for dissolved oxygen...
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On reliability assessment of ship machinery system in different autonomy degree; A Bayesian-based approach
PublicationAnalyzing the reliability of autonomous ships has recently attracted attention mainly due to epistemic uncertainty (lack of knowledge) integrated with automatic operations in the maritime sector. The advent of new random failures with unrecognized failure patterns in autonomous ship operations requires a comprehensive reliability assessment specifically aiming at estimating the time in which the ship can be trusted to be left unattended....
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Nonlinear Fuzzy Control System for Dissolved Oxygen with Aeration System in Sequencing Batch Reactor
PublicationBiological processes at a wastewater treatment plant are complex, multivariable, time varying and nonlinear. Moreover, interactions between the components are very strong. Control of dissolved oxygen is one of most important task at the plant. The level of dissolved oxygen in aerobic tanks has significant influence on behaviour and activity of microorganisms at the plant. Air for aerated tanks is supplied by the aeration system...
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Adaptive dynamic control allocation for dynamic positioning of marine vessel based on backstepping method and sequential quadratic programming
PublicationIt is generally assumed in dynamic positioning of over-actuated marine vessels that the control effectiveness matrix (input matrix) is known and constant, or, in case of fault information, it is estimated by the fault detection and diagnosis system. The purpose of the study is to develop the adaptive dynamic positioning control system for an over-actuated marine vessel in the presence of uncertainties and with emphasis on limited...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublicationDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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Neuronowa symulacja temperatury i ciśnienia pary w upuście parowego bloku energetycznego = Neural simulation of pressure and temperature fluctuations at steam extraction of power units with steam turbine
PublicationW artykule przedstawiono metodę symulacji neuronowej dla zastosowań w diagnostyce on-line bloków energetycznych. Model neuronowy opiera się na statycznych jednokierunkowych sieciach neuronowych (SSN) oraz na danych z parowego bloku energetycznego o mocy 200 MW. SSN obliczają wartości referencyjne parametrów cieplno-przepływowych dla aktualnego obciążenia obiektu. Określono wpływ architektury sieci i danych uczących na jakość symulacji...
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Comparative analysis of three‐phase dual active bridge converter with different transformer topology and modern universal control for DC microgrids
PublicationThe presented work discusses issues related to the use of modern multiphase topologies of Dual Active Bridge (DAB)-type converters. Converters of this type are widely used in most DC microgrid applications. The introduction emphasizes a comparative analysis between single-phase and multi-phase DAB topologies within high-power DC microgrids, delving into their respective advantages, drawbacks, design procedures, and considerations...
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Analysis of cyclone separator solutions depending on SEC outlet conditions in nCO2PP
PublicationUtilization of spray ejector condenser in order to carry out direct-contact condensation of vapour with inert gas (CO2) on a spray of subcooled liquid integrated with separator (to make pure CO2) has been proposed for the task of condensation and CO2 separation in the negative CO2 emission gas power plant. Condensation and separation has a significant impact on the thermodynamic efficiency of the entire negative CO2 emission gas...
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Areas of updraft air motion from WRF model simulations.
Open Research DataPresented dataset is a part of numerical modelling study focusing on the analysis of sea ice floes size distribution (FSD) influence on the horizontal and vertical structure of convection in the atmosphere. The total area and spatial arrangement of the updrafts indicates that the FSD affects the total moisture content and the values of area averaged...
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A new open-source software developed for numerical simulations usingdiscrete modeling methods
PublicationThe purpose of this work is to present the development of an open-source software based on a discrete description of matter applied to study the behavior of geomaterials. This software uses Object Oriented Programming techniques, and its methodology design uses three different methods, which are the Discrete Element Method (DEM) [F. Donzé, S.A. Magnier, Formulation of a three-dimensional numerical model of brittle behavior, Geophys....
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Justifying the prolongation of the service life of the bearing structure of a tank car when using Y25 bogies
PublicationThis paper substantiates the use of Y25 bogies under tank cars in order to prolong their service life. The reported study has been carried out for a tank car with rated parameters, as well as the actual ones, registered during full-scale research. Mathematical modeling was performed to determine the basic indicators of the tank car dynamics. The differential equations of motion were solved by a Runge-Kutta method using the Mathcad...
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Dynamic model of nuclear power plant turbine
PublicationThe paper presents the dynamic multivariable model of Nuclear Power Plant steam turbine. Nature of the processes occurring in a steam turbine causes a task of modeling it very difficult, especially when this model is intended to be used for on-line optimal process control (model based) over wide range of operating conditions caused by changing power demand. Particular property of developed model is that it enables calculations...
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Finite-element analysis of a base-isolated multi-storey steel building under seismic motions
PublicationNumerical simulation of the seismic behaviour of a multi-storey steel building, both fixed-base and base-isolated, under the 1940 El Centro earthquake was performed in this paper. The analyzed 4-storey building was decoupled from the shaking ground with the Polymeric Bearings, which can be considered a proposal of a new seismic isolation system. It consists of rectangular-shaped blocks made of a specially prepared flexible polymeric...
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Modelling tunnelling-induced deformation in stiff soils with a hyperelastic–plastic anisotropic model
PublicationIn this paper, the tunnelling-induced deformation in anisotropic stiff soils is analysed using FE modelling. The influence of material description is investigated rather than an advanced simulation of the tunnelling method. A new hyperelastic– plastic model is proposed to describe the anisotropic mechanical behaviour of stiff highly overconsolidated soil. This model can reproduce the superposition of variable stress-induced anisotropy...
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Incorporating installation effects into the probability analysis of controlled modulus columns
PublicationThis technical report presents the probabilistic analysis which integrates the Monte Carlo simulation (MCS) with random field theory to model the load–displacement behavior of Controlled Modulus Columns (CMCs) in overconsolidated Poznań clay. Presented study focuses on the practical aspects of statistical analysis of geotechnical data, numerical model development, and results evaluation. Variability and spatial distribution of...
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Comparative Analysis of Reactive Power Compensation Devices in a Real Electric Substation
PublicationA constant worldwide growing load stress over a power system compelled the practice of a reactive power injection to ensure an efficient power network. For this purpose, multiple technologies exist in the knowledge market out of which this paper emphasizes the usage of the flexible alternating current transmission system (FACTS) and presents a comparative study of the static var compensator (SVC) with the static synchronous compensator...
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Numerical crash analysis of the cable barrier
PublicationSafety barriers are used to increase road safety. Their basic task is to prevent the errant vehicle from getting off the road in places which are potentially dangerous for vehicle passengers. Barriers, which are used on European roads, must fulfill the requirements of EN 1317 standards by passing appropriate crash tests. Because of their high cost, numerical simulations are increasingly used to evaluate the properties of safety...
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Wirelessly Interfacing Objects and Subjects of Healthcare System – IoT Approach
PublicationWireless sensor networks, WSN, for which development has begun by military applications, are nowadays applied to all human activities; e.g. in medicine for patience monitoring or to reduce the effects of disasters. Therefore, the WSNs area has been also one of the emerging and fast growing scientific fields. Increasing interest of WSNs is even caused by equally intense growth of interest in the Internet of Things domain, IoT, in...
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Wojciech Sadowski prof. dr hab. inż.
PeopleWojciech Sadowski (born 2 February 1954 in Ostaszewo, Poland), scientist, engineer, professor at Gdansk University of Technology, specialist in solid state body physics, nanotechnology, optoelectronics. In 1973 he completed his high school education at High School Nicolaus Copernicus in Chelmno. In 1979 he graduate from Leningrad Electrotechnical Institute in Russia (former Soviet Union) with specialism in dielectrics and semiconductors....
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Long range molecular dynamics study of regulation of eukaryotic glucosamine-6-phosphate synthase activity by UDP-GlcNAc
PublicationGlucosamine-6-phosphate (GlcN-6-P) synthase catalyses the first and practically irreversible step in hexosamine metabolism. The final product of this pathway, uridine 5' diphospho N-acetyl-D-glucosamine (UDPGlcNAc), is an essential substrate for assembly of bacterialand fungal cell walls. Moreover, the enzyme is involved in phenomenon of hexosamine induced insulin resistance in type II diabetes, which makes it a potential target...
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Modelling and analysis of a synchronous generator in more electric aircraft power system using Synopsys/Saber simulator = Modelowanie i analiza generatora synchronicznego w systemie elektroenergetycznym nowoczesnego samolotu. Zastosowanie symulatora Synopsys/Saber
PublicationStreszczenie angielskie: A model for studying synchronous machine (SM) dynamic behaviour in more electric aircraft (MEA) power system is developed and implemented in the Synopys/Saber simulation environment. The modelling language MAST has been used to elaborate the SM model. The elaborated model exhibit a network with the same number of external terminals/ports as the real SM, and represents its behaviour in terms of the electrical...
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Reduced-Cost Microwave Design Closure by Multi-Resolution EM Simulations and Knowledge-Based Model Management
PublicationParameter adjustment through numerical optimization has become a commonplace of contemporary microwave engineering. Although circuit theory methods are ubiquitous in the development of microwave components, the initial designs obtained with such tools have to be further tuned to improve the system performance. This is particularly pertinent to miniaturized structures, where the cross-coupling effects cannot be adequately accounted...
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Chicken feather keratin as a source of bioactive peptides useful in prevention of metabolic disorders – in silico and in vitro hydrolysis
PublicationProtein derived bioactive peptides not only serve as nutrients but can also exert drug-like activity, e.g. antidiabetic, antihypertensive, or antimicrobial, to name a few. Most biopeptides have beneficial effects on health that make them attractive for nutraceutical applications. The majority of bioactive peptides have been obtained from food proteins, but protein-rich by-products generated by agriculture...
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Influence of Storage Time and Temperature on the Toxicity, Endocrine Potential, and Migration of Epoxy Resin Precursors in Extracts of Food Packaging Materials
PublicationThe aim of the present study was to establish a standard methodology for the extraction of epoxy resin precursors from several types of food packages (cans, multi-layered composite material, and cups) with selected simulation media (distilled water, 5% ethanol, 3% dimethyl sulfoxide, 5% acetic acid, artificial saliva) at different extraction times and temperatures (factors). Biological analyses were conducted to determine the acute...
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A stochastic approach for the solution of single and multi – objective optimisation problems of biological processes in sequencing batch reactor
PublicationThis paper investigates the impact of implementing single and multi-optimisation solutions on the biological treatment process in a sequencing batch reactor (SBR). The research is based on a case study of the water resource recovery facility (WRRF) in Swarzewo, Northern Poland. The paper introduces the adaptive extremum seeking control (ESC) method for dissolved oxygen (DO) concentration control and places it in a layered control structure....