Filters
total: 330
filtered: 304
-
Catalog
Chosen catalog filters
Search results for: MAXIMUM POWER POINT TRACKING (MPPT)
-
A Comparative Study of Fuzzy SMC with Adaptive Fuzzy PID for Sensorless Speed Control of Six-Phase Induction Motor
PublicationMulti-phase motors have recently replaced three-phase induction motors in a variety of applications due to the numerous benefits they provide, and the absence of speed sensors promotes induction motors with variable speed drives. Sensorless speed control minimizes unnecessary speed encoder cost, reduces maintenance, and improves the motor drive’s reliability. The performance comparison of the fuzzy sliding mode controller (FSMC)...
-
Doing well by doing good — CSR in a global context
PublicationMotivation: Nowadays, there is a general understanding that stakeholders are crucial for the successful enterprise. There is also a need to think about Corporate Social Responsibility (CSR) in a global context. Never before corporations enjoyed so much power and authority. Corporations need to evolve, re-think their strategies and change their processes accordingly. However, as of now, there is no agreed way of measuring overall...
-
Analytical ‘Steady-State’-Based Derivation and Clarification of the Courant-Friedrichs-Lewy Condition for Pipe Flow
PublicationThis article addresses the problem of choosing the optimal discretization grid for emulating fluid flow through a pipeline. The aggregated basic flow model is linearized near the operating point obtained from the steady state analytic solution of the differential equations under consideration. Based on this model, the relationship between the Courant number (μ) and the stability margin is examined. The numerically set coefficient...
-
An Efficient Noisy Binary Search in Graphs via Median Approximation
PublicationConsider a generalization of the classical binary search problem in linearly sorted data to the graph-theoretic setting. The goal is to design an adaptive query algorithm, called a strategy, that identifies an initially unknown target vertex in a graph by asking queries. Each query is conducted as follows: the strategy selects a vertex q and receives a reply v: if q is the target, then =, and if q is not the target, then v is a...
-
Mechanical Properties of Bio-Composites Based on Epoxy Resin and Nanocellulose Fibres
PublicationThe aim of our research was to investigate the effect of a small nanocellulose (NC) addition on an improvement of the mechanical properties of epoxy composites. A procedure of chemical extraction from pressed lignin was used to obtain nanocellulose fibers. The presence of nanoparticles in the cellulose pulp was confirmed by FTIR/ATR spectra as well as measurement of nanocellulose particle size using a Zetasizer analyzer. Epoxy...
-
Increased Certification of Semi-device Independent Random Numbers using Many Inputs and More Postprocessing
PublicationQuantum communication with systems of dimension larger than two provides advantages in information processing tasks. Examples include higher rates of key distribution and random number generation. The main disadvantage of using such multi-dimensional quantum systems is the increased complexity of the experimental setup. Here, we analyze a not-so-obvious problem: the relation between randomness certification and computational requirements...
-
Extremal thermal loading of a bifurcation pipe
PublicationThe subject of considerations is a spherical bifurcation pipe of a live steam made of steel P91, which is an element of a block of coal-fired power plant working with a 18K370 turbine. As experience shows, it is a very sensitive element of the boiler pipelines. An extreme work scenario for such a block has been adopted, in which the turbine is shutting down to a warm state three times in 24 hours. This is an action dictated by...
-
Accuracy of a low-cost autonomous hexacopter platforms navigation module for a photogrammetric and environmental measurements
PublicationA photogrammetry and environmental measurements from an unmanned aerial vehicle (UAV) are a low-cost alternative for a traditional aerial photogrammetry. A commercial off-the-shelf products (COTS) offers a variety of cheap components that a suitable to be used on board a UAV. In this paper a low-cost navigation module based on Ublox NEO-M8N GPS and Pixhawk flight controller have been described, as a main extrinsic parameters source...
-
Antenna Modeling Using Variable-Fidelity EM Simulations and Constrained Co-Kriging
PublicationUtilization of fast surrogate models has become a viable alternative to direct handling of fullwave electromagnetic (EM) simulations in EM-driven design. Their purpose is to alleviate the difficulties related to high computational cost of multiple simulations required by the common numerical procedures such as parametric optimization or uncertainty quantification. Yet, conventional data-driven (or approximation) modeling techniques...
-
Characteristics of LaCo 0.4 Ni 0.6-x Cu x O 3-δ ceramics as a cathode material for intermediate-temperature solid oxide fuel cells
PublicationIn this study, the effects of Cu-ion substitution on the densification, microstructure, and physical properties of LaCo0.4Ni0.6-xCuxO3-δ ceramics were investigated. The results indicate that doping with Cu ions not only enhances the densification but also promotes the grain growth of LaCo0.4Ni0.6-xCuxO3-δ ceramics. The Cu substitution at x ≤ 0.2 can suppress the formation of La4Ni3O10, while the excess Cu triggers the formation...
-
Noise Analysis of Continuous GPS Time Series of Selected EPN Stations to Investigate Variations in Stability of Monument Types
PublicationThe type of monument that a GPS antenna is placed on plays a significant role in noise estimation for each permanent GPS station. In this research 18 Polish permanent GPS stations that belong to the EPN (EUREF Permanent Network) were analyzed using Maximum Likelihood Estimation (MLE). The antennae of Polish EPN stations are placed on roofs of buildings or on concrete pillars. The analyzed data covers a period of 5 years from 2008...
-
A Low-Profile Metal-backed Dipole Loaded with Closely Coupled Arc-shaped Open Stubs for On-metal Tag Design with Wide Frequency Tuning Capability
PublicationThis research has presented a single-layer metal-backed dipole antenna, which consists of a feedline loaded with two pairs of closely-coupled arc-shaped open stubs, for designing a metal-mountable tag that features tuning capability over a wide range of frequency. Here, the stubs can generate sufficient inductive reactance for bringing down the tag resonant frequency tunable in both the regulated UHF RFID passbands (North American...
-
Sonocatalytic degradation of Bisphenol A from aquatic matrices over Pd/CeO2 nanoparticles: Kinetics study, transformation products, and toxicity
PublicationIn this work, different ratios of palladium – cerium oxide (Pd/CeO2) catalyst were synthesized and characterized, while their sonocatalytic activity was evaluated for the degradation of the xenobiotic Bisphenol A (BPA) from aqueous solutions. Sonocatalytic activity expressed as BPA decomposition exhibited a volcano-type behavior in relation to the Pd loading, and the 0.25Pd/CeO2 catalyst characterized by the maximum Pd dispersion...
-
City as a product. Architecture as an Economic Instrument. Are Global Cities People-Friendly Places?
PublicationWhile spending time in our everyday urban environment do we ever think how particular architecture influences the economic value of that space? Space has its measurable financial value. From the economic point of view a place can be treated as a product that fights for appearing in tourists’ and investors’ consciousnesses. Space - treated as an object of demand and supply - becomes an element in a marketing game. To reach its...
-
The occurrence of heavy metals and metal-resistant bacteria in water and bottom sediments of the Straszyn reservoir (Poland)
PublicationThe aim of this study is investigate the distribution of selected heavy metals (zinc, copper, lead, cadmium) and metal-resistant bacteria in water and bottom sediments of drinking water reservoir for Gdańsk (Poland). The research area - Straszyn Lake is a dam reservoir on Radunia river, of the total volume of 3 mln m3. Sediment and water sampling took place between May and October 2013 (eight series). Regarding metal concentration...
-
A DFT+U study of carbon nanotubes under influence of a gate voltage
PublicationA possibility of appearance of antiferromagnetic ordering in armchair carbon nanotubes and graphene is studied using density functional theory within a DFT+U approach. It is shown that the Coulomb repulsion between electrons in the -orbitals of graphene would need to reach a threshold value of ,...
-
Cross-talk Between the Heart and Arteries in Older 65+ Adults
PublicationRegulatory synchronization between the heart and the arterial walls is essential for optimal blood delivery to tissues. We investigated functional coherence between heart rhythm and aortic wall compliance in 30 volunteers aged 65 – 74. ECG and carotid and iliac pulse-wave were recorded and digitized at 2 kHz. Carotid-femoral pulse-wave transit time (cfTT) which reflex aortic compliance was assessed using the intersecting tangent...
-
Integrated algorithm for selecting the location and control of energy storage units to improve the voltage level in distribution grids
PublicationThis paper refers to the issue that mainly appears in distribution grids, where renewable energy sources (RES) are widely installed. In such grids, one of the main problems is the coordination of energy production time with demand time, especially if photovoltaic energy sources are present. To face this problem, battery energy storage units (ESU) can be installed. In recent years, more and more attention has been paid to optimizing...
-
Deep Eutectic Solvents: Properties and Applications in CO2 Separation
PublicationNowadays, many researchers are focused on finding a solution to the problem of global warming. Carbon dioxide is considered to be responsible for the “greenhouse” effect. The largest global emission of industrial CO2 comes from fossil fuel combustion, which makes power plants the perfect point source targets for immediate CO2 emission reductions. A state-of-the-art method for capturing carbon dioxide is chemical absorption using...
-
Historic railway stations, documentation and revitalization of the railway infrastructure facilities - protection of cultural and social heritage
PublicationThe article presents problems of documentation and adaptation of buildings which constitute the cultural heritage of the railway infrastructure facilities in Pomerania in Poland. Shows the potential and possibilityto be adopted for various purposes. This problem affects many sites and buildings, railway stations, railway warehouses, residential buildings, technical buildings, water towers, trackman shelters, bridges, viaducts,...
-
Wstępna ocena wielkości stężeń związków azotu i fosforu odprowadzanych z wodami powierzchniowymi do Zatoki Puckiej z terenu gminy Puck
PublicationThe ferilizers used in agriculture negatively affect the surface and groundwater quality. The Bay of Puck is a semi-closed part of the Gulf of Gdańsk, which is particularly vulnerable to eutrophication caused by the inflow of nutrient substances. The Bay is surrounded by the lands intensively used in agriculture. Also a number of touristic resorts is located on its coast. The streams and rivers carry the load of nitrogen and phosphorus...
-
Low temperature growth of diamond films on optical fibers using Linear Antenna CVD system
PublicationIt is not trivial to achieve a good quality diamond-coated fibre interface due to a large difference in the properties and composition of the diamond films (or use coating even) and the optical fibre material, i.e. fused silica. One of the biggest problems is the high temperature during the deposition which influences the optical fibre or optical fibre sensor structure (e.g. long-period gratings (LPG)). The greatest advantage of...
-
Tuning Electrochemical Performance by Microstructural Optimization of the Nanocrystalline Functional Oxygen Electrode Layer for Solid Oxide Cells
PublicationFurther development of solid oxide fuel cell (SOFC) oxygen electrodes can be achieved through improvements in oxygen electrode design by microstructure miniaturisation alongside nanomaterials implementation. In this work, improved electrochemical performance of an La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) cathode was achieved by the controlled modification of the La0.6Sr0.4CoO3-d (LSC) nanocrystalline interlayer introduced between a porous...
-
Cavitation-based technologies for pretreatment and processing of food wastes: Major applications and mechanisms – A review
PublicationConversion of food wastes to valuable products is an important topic for sustainable development. Feedstock hydrolysis is a stage strongly affecting the anaerobic digestion process, and resistance of food waste towards hydrolysis causes a decrease in product yield. Such as biomethane, biohydrogen, biohythane, VFAs, and lactic acids. Moreover, mass transfer is a serious limitation of transesterification for the production of biodiesel....
-
Inception and Propagation of Electrical Trees in the Presence of Space Charge in HVAC Extruded Cables
PublicationThis paper presents the space charge impact on the inception and propagation of electrical trees in cross-linked polyethylene (XLPE) insulation via simulations and experimentation. A 3D finite element analysis (FEA)-based modeling is proposed to simulate electrical trees via a needle embedded on the XLPE insulation. The proposed FEA model demonstrates the influence of the space charge magnitude and polarity on the initiation of...
-
Design and characterization of apatite La9.8Si5.7Mg0.3O26±δ-based micro-tubular solid oxide fuel cells
PublicationIn this study, electrolyte-supported (Cell A) and anode-supported (Cell B) micro-tubular solid oxide fuel cells (SOFCs) based on the La9.8Si5.7Mg0.3O26±δ (LSMO) electrolyte is built through an extrusion and dip-coating processes. The formulations and process conditions for these cells are established and optimized. Both cell configurations show no visible delamination or cracking, and reaction zones and inter-diffusion of any species...
-
STANY NIEUSTALONE TOWARZYSZĄCE POMIAROWI IMPEDANCJI PĘTLI ZWARCIA W OBWODACH WYJŚCIOWYCH ZASILACZY BEZPRZERWOWYCH UPS
PublicationW pracy przedstawiono metodykę i wyniki pomiarów stanów nieustalonych w zasilaczu bezprzerwowym (UPS) typu on - line. Do rejestracji zdarzeń po stronie zasilania i na wyjściu UPS wykorzystano dwa przyrządy do pomiaru jakości energii elektrycznej zsynchronizowane czasowo. Rejestratory kompresują uzyskane dane pomiarowe, co może wprowadzać dodatkowe błędy pomiaru wielkości mierzonych – napięć i prądów. Dodatkowe rejestracje oscyloskopem...
-
Doing Well by Doing Good- CSR in a Global Context
PublicationNowadays, there is a general understanding that stakeholders are crucial for the successful enterprise. There is also a need to think about Corporate Social Responsibility (CSR) in a global context. Never before corporations enjoyed so much power and authority. Corporations need to evolve, re-think their strategies and change their processes accordingly. However, as of now, there is no agreed way of measuring overall sustainability...
-
Tailoring properties of indium tin oxide thin films for their work in both electrochemical and optical label-free sensing systems
PublicationThis work is devoted to the identification properties of indium tin oxide (ITO) thin films responsible for their possible application in combined optical and electrochemical label-free sensing systems offering enhanced functionalities. Since any post-processing would make it difficult to identify direct relation between deposition parameters and properties of the ITO films, especially when deposition on temperature-sensitive substrates...
-
ANALYSIS AND OPTIMIZATION OF ELECTRIC VEHICLE CHARGING PROCESSES IN TRANSACTIVE ENERGY SYSTEMS
PublicationThe implementation of smart charging of electric vehicles allows operators of local power networks and electricity suppliers to implement new business models for the interaction of electric vehicles with the network. In addition to the optimal selection of Microgrid capacities when charging electric vehicles, it is also important to use different charging methods. To satisfy the interests of all participants of local systems from...
-
Characteristics of La0.8Sr0.2Ga0.8Mg0.2O3-delta -supported micro-tubular solid oxide fuel cells with bi-layer and tri-layer electrolytes
PublicationIn this study, La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM)-supported micro tubular solid oxide fuel cells (T-SOFCs) with two different configurations, one containing an LSGM–Ce0.6La0.4O2−δ (LDC) bi-layer electrolyte (Cell A) and one containing an LDC–LSGM–LDC tri-layer electrolyte (Cell B), were fabricated using extrusion and dip-coating. After optimizing the paste formulation for extrusion, the flexural strength of the dense and uniform LSGM...
-
Electrode-based floating treatment wetlands: Insights into design operation factors influencing bioenergy generation and treatment performance
PublicationExponential increases in energy consumption and wastewater have often irreversible environmental impacts. As a result, bio-electrochemical devices like microbial fuel cells (MFCs), which convert chemical energy in organic matter to electricity using exoelectrogenic bacteria, have gained interest. However, operational factors affecting efficiency and energy output need further study. This research investigated bioenergy production...
-
Analysis of cyclone separator solutions depending on spray ejector condenser conditions
PublicationThe core design strategy for minimizing CO2 emissions in gas power plant entails combining a spray ejector condenser (SEC) and separator to accomplish steam condensation and CO2 purification. This innovative process involves direct-contact condensation of steam with CO2, facilitated by interaction with a subcooled water spray, along with a cyclone separator mechanism intended for generating pure CO2. The investigation of the SEC...
-
A dissimilar welded joint of grade 92 steel and AISI 304L steel obtained using IN82 buttering and IN617 fller: relationship of microstructure and mechanical properties
PublicationUnfavourable operating conditions of equipment in the energy industry resulting from high-temperature loads determine the need to use special materials and technological solutions, including welding procedures. In this article, buttering using IN82 (ERNiCr-3) consumables was proposed as a method to improve the weldability of grade 92 steel joined by the gas tungsten arc welding (GTAW) process with AISI 304L (IN617 fller). The...
-
Activated Tungsten Inert Gas Weld Characteristics of P91 Joint for Advanced Ultra Supercritical Power Plant Applications
PublicationActivated Tungsten Inert Gas (A-TIG) welding, a variant of tungsten inert gas (TIG) welding, was used for welding P91. In Generation IV power plants, P91 welds are prone to premature failure due to the presence and formation of brittle phases and creep at high temperatures. When performing A-TIG welding, the flux composition plays a role in the reversal of the Marangoni flow in the weld pool, which ultimately determines the level...
-
Sustainable recovery of plant essential Nitrogen and Phosphorus from human urine using industrial coal fly ash
PublicationCoal-based thermal power plants play a pivotal role in meeting global energy demand. The amount of fly ash generated from these plants increases every year, and its successful use has posed a significant environmental risk in the last decade. In this study, coal fly ash was packed in a fixed-bed adsorption column to remove Urea–N from synthetic human urine. To assess the efficacy of fly ash in the removal of Nitrogen, various process...
-
Influence of PWHT Parameters on the Mechanical Properties and Microstructural Behavior of Multi-Pass GTAW Joints of P92 Steel
PublicationThe 9% Cr steels were developed for ultra-supercritical (USC) power plants to meet the requirements of high operating temperature and pressure. These steels are produced to operate at high temperatures where impact toughness is not a concern; however, it becomes important for the welded joints to have good impact toughness at room temperature for manufacturing. The present work investigates the effect of the post-weld heat treatment...
-
Społeczne koszty niealimentacji. The Social Costs of Default on Child Maintenance Payment.
Publication"Niniejszy artykuł opisuje historię kryminalizacji przestępstwa niealimentacji w polskich kodeksach karnych. We wszystkich polskich kodeksach karnych: kodeksie karnym z 1932 r., kodeksie karnym z 1969 r. oraz w kodeksie karnym z 1997 r. ujęto przestępstwo niealimentacji. Aktualna maksymalna sankcja z tytułu przestępstwa niealimentacji jest niższa niż w kodeksie karnym z 1932 r. Sankcje karne zawsze powinny być ostatecznością...
-
Numerical Issues and Approximated Models for the Diagnosis of Transmission Pipelines
PublicationThe chapter concerns numerical issues encountered when the pipeline flow process is modeled as a discrete-time state-space model. In particular, issues related to computational complexity and computability are discussed, i.e., simulation feasibility which is connected to the notions of singularity and stability of the model. These properties are critical if a diagnostic system is based on a discrete mathematical model of the flow...
-
THE ART OF VIRTUAL INFORMATION EXCHANGE AND ITS INFLUENCE ON REAL CITY SPACE
PublicationThe paper investigates the impact of the new genres of contemporary public art based on the virtual information exchange in real spaces of the cities. On the basis of theoretical approaches, trans-disciplinary surveys and case studies, the paper focuses on the art that not only relies on the technological support but also refers to the new public sphere, where people are co-creators of the art object giving their personal input...
-
Ukraine’s Energy Security in Strategies
PublicationDuring the independence period, the Ukrainian government has published two energy security strategies. The first strategy was adopted in 2006 and the second one in 2016. Both documents provided a similar definition of energy security. The aims of the first strategy, covering the period 2006–2030, were the restructuring of the fuel and energy complex using new technologies, increase of energy efficiency and ensuring market prices...
-
Low-Cost Design Optimization of Microwave Passives Using Multi-Fidelity EM Simulations and Selective Broyden Updates
PublicationGeometry parameters of contemporary microwave passives have to be carefully tuned in the final stages of their design process to ensure the best possible performance. For reliability reasons, the tuning has to be to be carried out at the level of full-wave electromagnetic (EM) simulations. This is because traditional modeling methods are incapable of quantifying certain phenomena that may affect operation and performance of these...
-
Investigation of long-range dependencies in the stochastic part of daily GPS solutions
PublicationThe long-range dependence (LRD) of the stochastic part of GPS-derived topocentric coordinates change (North, East, Up) results with relatively high autocorrelation values with a focus on self-similarity. One of the reasons for such self-similarity in the GPS time series are noises that are commonly recognised to prevail in the form of the flicker noise model. To prove the self-similarity of the stochastic part of GPS time series...
-
CO2 capture through direct-contact condensation in a spray ejector condenser and T- junction separator
PublicationThe design principle underlying the steam condensation and CO2 purification in a gas power plant with a focus on reducing CO2 emissions encompasses the deployment of a spray ejector condenser (SEC) and separator. This innovative system facilitates direct-contact condensation of steam with non-condensable gas (CO2) by inter acting with a spray of subcooled water, seamlessly integrated with a T-junction separator mechanism aimed...
-
Pavement ageing influence on tyre/road noise
PublicationRoad surface should be constructed in a way that ensures safe and comfortable traffic conditions, not only when it is newly paved but also during its entire lifetime. An important factor in the asphalt mixture design process is also the expected pavement durability and stability of pavement properties over time. In many countries, road surface starts to play a significant role in traffic noise reduction actions. Selecting a particular...
-
The interaction between bacterial abundance and selected pollutants concentration levels in an arctic catchment (southwest Spitsbergen, Svalbard)
PublicationPersistent organic pollutants (POPs) have been a topic of interest in environmental sciences for > 60 years. POPs in the Arctic have been investigated since the 1970s, when first atmospheric measurements revealed the presence of these pollutants in the polar regions. Major contaminant transport routes to the Arctic include atmospheric and oceanic transport, as well as inflow from rivers and sea ice. The sources of pollutants, such...
-
Scale effect in the self-propulsion prediction for Ultra Large Container Ship with contra-rotating propellers
PublicationThis article addresses the problem of the scale effect for an Ultra Large Container Ship (ULCS) with a novel twin-crp-pod propulsion system. Twin-crp-pod steering-propulsion arrangement is an innovative solution that gains from three well-known systems: twin-propeller, contra-rotating propellers and pod propulsors. It is expected that applying the twin-crp-pod system to the analysed Ultra Large Container Ship will increase propulsion...
-
Genetic Hybrid Predictive Controller for Optimized Dissolved-Oxygen Tracking at Lower Control Level
PublicationA hierarchical two-level controller for dissolvedoxygenreference trajectory tracking in activated sludge processeshas been recently developed and successfully validated on a realwastewater treatment plant. The upper level control unit generatestrajectories of the desired airflows to be delivered by theaeration system to the aerobic zones of the biological reactor. Anonlinear model predictive control algorithm is applied to designthis...
-
Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures
PublicationThree low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction...
-
UUV and AUV Vehicles as the autonomous systems for naval applications
PublicationThere is a growing pressure to investigate how to design and build the unmanned underwater vehicles of different types which are devoted towards performing many tasks under the water surface according to the data missions. During the recent years the Department of Ship Design and Subsea Robotics, Faculty of Ocean Engineering and Ship Technology, Gdansk University of Technology designed and built a few types of unmanned underwater...