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Search results for: MARINE PROPULSION UNIT
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Seabed Topography Changes in the Sopot Pier Zone in 2010–2018 Influenced by Tombolo Phenomenon
PublicationBathymetric surveys of the same body of water, performed at regular intervals, apart from updating the geospatial information used to create paper and electronic maps, allow for several additional analyses, including an evaluation of geomorphological changes occurring in the coastal zone. This research is particularly important in places where the shape of the coastal zone has been violently disturbed, including by human activity....
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Selektywne chłodzenie mózgu noworodka po niedotlenieniu okołoporodowym. Cześć 3. Hybrydowy system selektywnego chłodzenia mózgu noworodka
PublicationZapoczątkowane brakiem tlenu procesy biochemiczne mają zgubne skutki dla układu nerwowego, w szczególności rozwijającego się. Hipotermia, czyli stan oziębienia poniżej pewnych wartości temperatur, spowalnia znacznie lub całkowicie wyhamowuje poszczególne reakcje, i to leży u podstaw jej własności neuroprotekcyjnych. Powyższe twierdzenie poparte licznymi faktami naukowymi leży u podstaw koncepcji selektywnego chłodzenia mózgu i...
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Efficient algorithm for blinking LED detection dedicated to embedded systems equipped with high performance cameras
PublicationThis paper presents the concept and implementation of an efficient algorithm for detection of blinking LED or similar signal sources. Algorithm is designed for embedded devices equipped with high performance cameras being a part of an indoor positioning embedded system. An algorithm to be implemented in such a system should be efficient in terms of computational power what is hard to be achieved when large amount of data from camera...
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No-Wait & No-Idle Open Shop Minimum Makespan Scheduling with Bioperational Jobs
PublicationIn the open shop scheduling with bioperational jobs each job consists of two unit operations with a delay between the end of the first operation and the beginning of the second one. No-wait requirement enforces that the delay between operations is equal to 0. No-idle means that there is no idle time on any machine. We model this problem by the interval incidentor (1, 1)-coloring (IIR(1, 1)-coloring) of a graph with the minimum...
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Measurement of luminance and color uniformity of displays using the large-format scanner
PublicationUniformity of display luminance and color is important for comfort and good perception of the information presented on the display. Although display technology has developed and improved a lot over the past years, different types of displays still present a challenge in selected applications, e.g. in medical use or in case of multi-screen installations. A simplified 9-point method of determining uniformity does not always produce...
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The new concept of capillary forces aided evaporator for application in domestic organic rankine cycle
PublicationThis paper presents studies on the possibility of applying capillary forces induced in the porous structure to a modern design of evaporator. The potential application of such heat exchanger is for example an evaporator of the domestic micro combined heat and power (CHP) unit. One of the problems in the micro-CHP is excessive demand for pumping power. The proposed design helps in overcoming that issue. In the evaporator outlined...
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Operational problems of large power diesel engines combusting biofuels, considered togetherwith assessment of their operation
PublicationWithin this article the issue of large power self ignition engines fed with biofuels has been undertaken. The analysis focused mainly on operation problems. There has been noticed some advantages and difficulties associated with the biofuel application to self ignition engines. The research problem has been characterised and the research purposes have been proposed enabling the most profitable formation of energetic features of...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Evaluation of structural change during fast transformation process of cross-linked NR into liquid NR by light pyrolysis
PublicationThe presence of cross-linked networks in rubber creates a tremendous problem for recycling and reusing of waste rubber. Fast transformation of cross-linked natural rubber (NR) into liquid natural rubber was carried out by light pyrolysis in temperature range from 240 to 300 °C in variable time (in range: 1–30 min). The transformation efficiency was evaluated by measuring the sol fraction and the cross-link density of the gel fraction....
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Smart sustainable cities : Reconnaissance Study
PublicationThe global urban population is expected to grow by 63 percent between 2014 and 2050 – compared to an overall global population growth of 32 percent during the same period. Megacities with over 20-million inhabitants will see the fastest increase in population – and at least 13 new megacities are expected by 2030, in addition to the 28 existing today. The fastest growing urban centres contain around one-million inhabitants, and...
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Inverse Flood Routing Using Simplified Flow Equations
PublicationThe paper considers the problem of inverse flood routing in reservoir operation strategy. The aim of the work is to investigate the possibility of determining the hydrograph at the upstream end based on the hydrograph required at the downstream end using simplified open channel flow models. To accomplish this, the linear kinematic wave equation, the diffusive wave equation and the linear Muskingum equation are considered. To achieve...
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Structure and transport properties of triple-conducting BaxSr1−xTi1−yFeyO3−δ oxides
PublicationIn this work, BaxSr1−xTi1−yFeyO3−δ perovskite-based mixed conducting ceramics (for x = 0, 0.2, 0.5 and y = 0.1, 0.8) were synthesized and studied. The structural analysis based on the X-ray diffraction results showed significant changes in the unit cell volume and Fe(Ti)–O distance as a function of Ba content. The morphology of the synthesized samples studied by means of scanning electron microscopy has shown different microstructures...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Neural Approximators for Variable-Order Fractional Calculus Operators (VO-FC)
PublicationThe paper presents research on the approximation of variable-order fractional operators by recurrent neural networks. The research focuses on two basic variable-order fractional operators, i.e., integrator and differentiator. The study includes variations of the order of each fractional operator. The recurrent neural network architecture based on GRU (Gated Recurrent Unit) cells functioned as a neural approximation for selected...
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Advantageous conditions of saccharification of lignocellulosic biomass for biofuels generation via fermentation processes
PublicationProcessing of lignocellulosic biomass includes four major unit operations: pre-treatment, hydrolysis, fermentation and product purifcation prior to biofuel generation via anaerobic digestion. The microorganisms involved in the fermentation metabolize only simple molecules, i.e., monosugars which can be obtained by carrying out the degradation of complex polymers, the main component of lignocellulosic biomass. The object of this...
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Power System Dynamics. Stability and Control. 3rd edition
PublicationComprehensive, state-of-the-art review of information on the electric power system dynamics and stability. It places the emphasis first on understanding the underlying physical principles before proceeding to more complex models and algorithms. The book explores the influence of classical sources of energy, wind farms and virtual power plants, power plants inertia and control strategy on power system stability. The book cover...
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Reactivity of Phosphanylphosphinidene Complex of Tungsten(VI) toward Phosphines: A New Method of Synthesis of catena-Polyphosphorus Ligands
PublicationThe reactivity of an anionic phosphanylphosphinidene complex of tungsten(VI), [(2,6-i-Pr2C6H3N)2(Cl)- W(η2-t-Bu2P=P)]Li·3DME toward PMe3, halogenophosphines, and iodine was investigated. Reaction of the starting complex with Me3P led to formation of a new neutral phosphanylphosphinidene complex, [( 2,6-i-Pr2C6H3N)2(Me3P)W(η2-t-Bu2P=P)]. Reactions with halogenophosphines yielded new catena-phosphorus complexes. From reaction with...
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An Intelligent Approach to Short-Term Wind Power Prediction Using Deep Neural Networks
PublicationIn this paper, an intelligent approach to the Short-Term Wind Power Prediction (STWPP) problem is considered, with the use of various types of Deep Neural Networks (DNNs). The impact of the prediction time horizon length on accuracy, and the influence of temperature on prediction effectiveness have been analyzed. Three types of DNNs have been implemented and tested, including: CNN (Convolutional Neural Networks), GRU (Gated Recurrent...
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Pluralist View on Inequality from Luxemburg Income Study (LIS)
PublicationThe authors start by reviewing the history of the Luxembourg Income Study (LIS), originating from an interdisciplinary project involving economists, sociologists, and political scientists, centered on the cross-country perspective in inequality analysis. They then conduct a meta-analysis of the papers produced by scholars who have taken advantage of the data availability, showing how the theme of income/wealth inequality has been...
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Decreasing CO2 Emissions By Reducing Tire Rolling Resistance
PublicationThe first motor vehicle was built by Nicolas Cugnot almost 250 years ago and since then there has been a continuous process of motor vehicles’ improvements, as well as development of new road pavements. The fuel crisis of the 70s of the 20th century made it clear to vehicle builders that measures should be taken to reduce vehicle fuel consumption and it contributed to an increased interest in electric vehicles. Although significant...
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Reinforced concrete thin wall dome after eighty years of operation in maritime climate environment
PublicationThe paper presents a description of the construction elements of the Gdynia Seaport main hall dome. Firstly, it provides information about the technical condition of the dome’s structure. Secondly, it examines the strength analysis of the thin-walled reinforced concrete dome covering. Throughout the last 80 years the building has been exposed to an unfavourable marine climate. The analysis of the state of stress and deformations...
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Multi-layered mineral glass units used as viewport elements of underwater ship structures
PublicationIn the paper, Authors deals with viewport elements of underwater marine constructions. If a single-plate viewport constructions are considered, big thicknesses of the glass plate are required to resist the pressure. To build the viewports from the commercially accessible glass panes, multi-layered glass units are proposed in the paper. Numerical calculations are presented, summarized and compared with experimental tests. Focusing...
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The abrasive wear resistance of coatings manufactured on high-strength low-alloy (HSLA) offshore steel in wet welding conditions
PublicationSome marine and offshore structure elements exploited in the water cannot be brought to the surface of the water as this will generate high costs, and for this reason, they require in-situ repairs. One of the repair techniques used in underwater pad welding conditions is a wet welding method. This paper presents an investigation of the abrasive wear resistance of coatings made in wet welding conditions with the use of two grades...
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Spatial Differences in the Chemical Composition of Surface Water in the Hornsund Fjord Area: A Statistical Analysis with A Focus on Local Pollution Sources
PublicationSurface catchments in Svalbard are sensitive to external pollution, and yet what is frequently considered external contamination may originate from local sources and natural processes. In this work, we analyze the chemical composition of surface waters in the catchments surrounding the Polish Polar Station in Svalbard, Hornsund fjord area. We have pooled unpublished and already published data describing surface water composition...
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Phylogenetics and phylogeography of red deer mtDNA lineages during the last 50 000 years in Eurasia
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Zastosowanie testu biologicznego Microtox do oceny skuteczności działania oczyszczalni ścieków bytowo-przemysłowych
PublicationOcena efektywności procesu oczyszczania ścieków z zastosowaniem biotestu Microtox® na przykładzie wybranej oczyszczalni Powszechnie praktykowanym sposobem wprowadzania ścieków oczyszczonych do środowiska jest ich punktowy zrzut do wód powierzchniowych. Różnorodność działalności prowadzonej w ramach współczesnej gospodarki sprawia, że do oczyszczalni docierają nie tylko substancje, których oznaczanie jest wymagane przez przepisy...
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Process Control and Investigation of Oxidation Kinetics of Postoxidative Effluents Using Gas Chromatography with Pulsed Flame Photometric Detection (GC-PFPD)
PublicationThis article presents the results of investigations on the use of headspace analysis and gas chromatography with pulsed flame photometric detection (HSA-GC-PFPD) to evaluate the effectiveness of oxidation of postoxidative effluents from the production of bitumens. Samples of effluents from the bitumen oxidation unit were used in the experiments. In addition, the kinetics of effluent oxidation was also investigated. The content...
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Hierarchical dissolved oxygen control for activated sludge processes
PublicationA hierarchical controller for tracking the dissolved oxygen reference trajectory in activated sludge processes is proposed and investigated. The removal of nitrogen and phosphorous from wastewater is considered. Typically, an aeration system itself is a complicated hybrid nonlinear dynamical system with faster dynamics compared to the internal dynamics of the dissolved oxygen in a biological reactor. It is a common approach to...
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The influence of screw configuration and screw speed of co-rotating twin screw extruder on the properties of products obtained by thermomechanical reclaiming of ground tire rubber
PublicationThe results of our investigations on the process of continuous thermomechanical reclaiming of ground tire rubber (GTR) carried out using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear forces. The influence of screw configuration and screw speed on breaking of chemical crosslink bonds contained in ground tire...
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Experimental investigation on heat pipes supported by soy wax and lauric acid for electronics cooling
PublicationThis paper presents an experimental study of heat pipes for electronics cooling that were supported by energy storage materials (i.e. phase change materials - PCMs) coated at the adiabatic section. The PCMs utilized included two materials, namely lauric acid and soy wax, the latter being considered as a more cost-effective alternative. The study focused on three different powers: 20 W, 25 W, and 30 W. Both heating, cooling, and...
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The shallow sea experiment with usage of linear hydrophone array
PublicationPurpose of this article is to present designed and made linear hydrophone array and the results obtained during in situ trails on Gulf of Gdańsk. The measuring system allowed to localize hydrophones in the selected points and perform measurements in both the horizontal antenna positioning and vertical. Made in this way recordings allow creating accurate 3D imaging of sound intensity/propagation. During research three floating objects...
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The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
PublicationThe search for new ways to recycling of rubber waste has been the aim of many studies conducted by research centers and companiesworldwide. The results of our investigations on the process of continuous thermomechanical devulcanization of ground tire rubber using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear...
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Retrievable strain measuring system in screw displacement piles - readings and results interpretation problems
PublicationStatic load tests on foundation piles are generally carried out in order to determine load – displacement characteristic of the pile. For more detailed information, e.g. force distribution along the shaft, load transfer mechanism and characteristics of soil-structure interaction (unit resistance curves t-z, q-z) additional pile instrumentation is required. Most popular techniques focus on direct concrete strain measurements and...
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A Data Driven Model for Predicting RNA-Protein Interactions based on Gradient Boosting Machine
PublicationRNA protein interactions (RPI) play a pivotal role in the regulation of various biological processes. Experimental validation of RPI has been time-consuming, paving the way for computational prediction methods. The major limiting factor of these methods has been the accuracy and confidence of the predictions, and our in-house experiments show that they fail to accurately predict RPI involving short RNA sequences such as TERRA RNA....
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Copper(I) halide cluster-based coordination polymers modulated by chiral ditopic dithiodianthranilide ligands: synthesis, crystal structure and photoluminescence
PublicationReaction of copper(I) halides with chiral dithiodianthranilidesmdtaandbdtaafforded polymeric complexeswhere polynuclear CuX clusters were linked together by ditopic bridging ligands into 1D chains or 2D layerstructures. In the case of racemic ligands double stranded chain polymers were formed where the Cu4X4(X = I or Br) cores are connected by enantiomeric pairs of the ditopic ligands. In contrast, a homochiralmdtaligand created...
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Combined cold supply system for ship application based on low GWP refrigerants - Thermo-economic and ecological analyses
PublicationThe withdrawal of popular high-GWP refrigerants will significantly affect maritime industry. Refrigeration and air conditioning systems currently used on ships are not ready to fulfil future limitations. Therefore, there is a need for system, which will operate with low-GWP refrigerants and at the same time will be efficient and reliable in difficult environmental conditions. This paper explains the concept of a cold supply system,...
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Investigation of the Combustion Processes in the Gas Turbine Module of an FPSO Operating on Associated Gas Conversion Products
PublicationIn this paper, we consider the issue of thermo-chemical heat recovery of waste heat from gas turbine engines for the steam conversion of associated gas for offshore vessels. Current trends in the development of offshore infrastructure are identified, and the composition of power plants for mobile offshore drilling units and FPSO vessels is analyzed. We present the results of a comparison of power-to-volume ratio, power-to-weight...
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Superconductivity in Metal-Rich Chalcogenide Ta2Se
PublicationThe metal–metal bond in metal-rich chalcogenide is known to exhibit various structures and interesting physical properties. Ta2Se can be obtained by both arc-melting and solid-state pellet methods. Ta2Se crystallizes a layered tetragonal structure with space group P4/nmm (No. 129; Pearson symbol tP6). Each unit cell consists of four layers of body-centered close-packing Ta atoms sandwiched between two square nets of Se atoms, forming...
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Estimation of Screw Displacement Pile-Bearing Capacity Based on Drilling Resistances
PublicationThis article presents an engineering, empiricalmethod of estimating the bearing capacity and settlementcharacteristics Q-s of screw displacement piles andcolumns, based on soil resistance encountered during thedrilling to form piles/columns in the ground. The methodwas developed on the basis of correlation analyses of thetest results of 24 piles made during the “DPDT-Auger”research project (Krasiński et al., 2022a). In the proposedmethod,...
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Deformation of an elastic second gradient spherical body under equatorial line density of dead forces
PublicationWe consider deformations of an elastic body having initially a spherical shape. Assumed deformation energy depends on the first and second gradient of displacements. We apply an equatorial line density of dead loads, that are forces per unit line length directed in radial direction and applied along the equator of the sphere. We restrict ourselves our analysis to the case of linearized second strain gradient isotropic elasticity...
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WYDATKI INWESTYCYJNE WOJEWÓDZTW SAMORZĄDOWYCH PO WPROWADZENIU INDYWIDUALNEGO WSKAŹNIKA ZADŁUŻENIA
PublicationOkreślenie dopuszczalnego poziomu zadłużenia jest ważną kwestią dla każdej jednostki samorządu terytorialnego w Polsce, a jej ranga jeszcze rośnie, jeśli samorząd odczuwa silną presję na dbanie o rozwój obszaru, na którym funkcjonuje, borykając się równocześnie z niedostatkiem dochodów. Taka sytuacja dotyczy większości województw samorządowych, które spośród wszystkich szczebli struktury samorządowej...
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Challenges associated with development of AUV - unmanned autonomous underwater vehicles to be operated using the AI-based control systems
PublicationThe last decade has been devoted towards further development of the UUV unmanned underwater vehicles which may be of two types. There are the USV unmanned surface vehicles and UUV unmanned underwater vehicles. There is a growing interest to work out and implement the fully advanced AUV autonomous underwater vehicles. The main drivers towards development of such the vehicles are the technologies of autonomous systems, sensors and...
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EMISJA AKUSTYCZNA JAKO SYGNAŁ DIAGNOSTYCZNY ODWZOROWUJĄCY ZMĘCZENIOWE ZUŻYCIE WARSTW ŚLIZGOWYCH PANWI ŁOŻYSK GŁÓWNYCH I KORBOWYCH SILNIKÓW O ZAPŁONIE SAMOCZYNNYM
PublicationW artykule przedstawiono wyniki badań laboratoryjnych, z których wynika, że emisja akustyczna (EA) może być uznana za sygnał diagnostyczny, przydatny do identyfikacji stanu technicznego łożysk głównych i korbowych okrętowych silników o zapłonie samoczynnym. Wykazano w nim bowiem, że parametry emisji akustycznej takie jak: czas rejestracji, energia sygnału, amplituda sygnału, ilość przekroczeń poziomu dyskryminacji, czas narastania,...
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Assessment of Supercapacitor’s Quality by Means of Low Frequency Noise
PublicationLow frequency noise is a well-known tool for quality and reliability assessment of electronic devices. This phenomenon is observed in different electrochemical devices as well (e.g., smart windows, electrochemical corrosion processes). Thus, we can assume that the same tool can be used to asses quality of supercapacitors. Their quality is usually determined only by capacitance and/or equivalent series resistance (ESR), or impedance....
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Crystal structures of aminotransferases Aro8 and Aro9 from Candida albicans and structural insights into their properties
PublicationAminotransferases catalyze reversibly the transamination reaction by a ping-pong bi-bi mechanism with pyridoxal 5′-phosphate (PLP) as a cofactor. Various aminotransferases acting on a range of substrates have been reported. Aromatic transaminases are able to catalyze the transamination reaction with both aromatic and acidic substrates. Two aminotransferases from C. albicans, Aro8p and Aro9p, have been identified recently, exhibiting...
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Evaluation of respiration capacity of VF in hybrid constructed wetland systems.
PublicationThree VF-beds operating in hybrid constructed wetlands in configuration HF-VF-HF were analysed. These hybrid constructed wetlands provide the II stage biological treatment. They are located in Pommerania voivodship, in Sarbsk, Wiklino and Wieszyno, and their capacities are 29.5, 14.2 and 21.6 m3/d, respectively. The article focuses on performance and operation of VF-CW plants during one year. Based on removal of organic matter...
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Wideband High-Gain Low-Profile Series-Fed Antenna Integrated with Optimized Metamaterials for 5G millimeter Wave Applications
PublicationThis paper presents a series-fed four-dipole antenna with a broad bandwidth, high gain, and compact size for 5G millimeter wave (mm-wave) applications. The single dipole antenna provides a maximum gain of 6.2 dBi within its operational bandwidth, which ranges from 25.2 to 32.8 GHz. The proposed approach to enhance both gain and bandwidth involves a series-fed antenna design. It comprises four dipoles with varying lengths, and a...
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Testing Stability of Digital Filters Using Multimodal Particle Swarm Optimization with Phase Analysis
PublicationIn this paper, a novel meta-heuristic method for evaluation of digital filter stability is presented. The proposed method is very general because it allows one to evaluate stability of systems whose characteristic equations are not based on polynomials. The method combines an efficient evolutionary algorithm represented by the particle swarm optimization and the phase analysis of a complex function in the characteristic equation....
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Scheduling with Complete Multipartite Incompatibility Graph on Parallel Machines: Complexity and Algorithms
PublicationIn this paper, the problem of scheduling on parallel machines with a presence of incompatibilities between jobs is considered. The incompatibility relation can be modeled as a complete multipartite graph in which each edge denotes a pair of jobs that cannot be scheduled on the same machine. The paper provides several results concerning schedules, optimal or approximate with respect to the two most popular criteria of optimality:...
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Power Hardware-In-the-Loop Approach for Autonomous Power Generation System Analysis
PublicationThe article presents the Power Hardware-In-the-Loop (PHIL) dynamic model of a synchronous generator of 125 kVA for autonomous power generation system analysis. This type of system is typically composed of electrical energy sources in the form of several diesel generator units with synchronous machines, the main distribution switchboard and different loads. In modern power distribution systems, the proposed power management strategies...