Search results for: EFFICIENCY ANALYSIS
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Self–Organizing Map representation for clustering Wikipedia search results
PublicationThe article presents an approach to automated organization of textual data. The experiments have been performed on selected sub-set of Wikipedia. The Vector Space Model representation based on terms has been used to build groups of similar articles extracted from Kohonen Self-Organizing Maps with DBSCAN clustering. To warrant efficiency of the data processing, we performed linear dimensionality reduction of raw data using Principal...
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Energy Losses Due to Imperfect Payment Infrastructure and Payment Instruments
PublicationOne of the strategic objectives of the European Union is a reduction in greenhouse gas emissions and improvement of energy efficiency by at least 32.5% in different areas of the economy by 2030. However, little is known about the impact of payment in retail on energy consumption. The purpose of this paper is to assess the chain of losses of time and energy, and therefore financial losses, that occur due to the imperfection of payment...
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Impact of dyes isomerization effect on the charge transfer phenomenon occurring on the dye/nanosemiconductor interface
PublicationThe present work aimed to find the answer how does the isomerization of the Ru based dyes affect the overall photon-to-current efficiency of the DSSCs and to explain the charge transfer phenomenon occurring on the dye/ nanosemiconductor interface. Therefore, electronic and optical properties of three bipyridine derivatives anchored on the TiO2 electrode were investigated by computational simulations based on quantum chemistry codes...
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The share of investments in gold and oil using the example of selected European stock exchanges– A comparative analysis
PublicationIn this article, optimal investment portfolios with minimal risk and maximum efficiency were calculated. The portfolios were designated for ten selected European stock exchanges, based on the listings of the twenty largest companies in each of those markets. All calculations were made based on company shares only, company shares and investments in gold, shares of companies and investments in crude oil as well as shares of companies...
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Mesophilic and thermophilic dark fermentation course analysis using sensor matrices and chromatographic techniques
PublicationProduction of biofuels from biomass is expected to benefit the society and the environment. At present, bio waste residues processing includes hydrolysis, dark fermentation, photofermentation, pyrolysis, gasification, and chemical synthesis. As the composition and the chemical structure of organic substances affect the efficiency of mentioned processes, it is believed that the glucose concentration is a crucial parameter for the...
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EVALUATION OF THE USE OF M2M-TYPE NB-IoT AND LTE TECHNOLOGIES FOR MARITIME COMMUNICATION SYSTEMS
PublicationThe development of IoT (the Internet of Things) wireless transmission opens a new era in communication systems. In the next years, the development and implementation of IoT systems will be very dynamic. It can be seen that the solutions of LTE – NB-IoT (Long Term Evolution – Narrowband IoT) transmission devices are implemented in a wide range of terrestrial solutions, e.g. smart grids. This paper aims to analyse the possibility...
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Gold nanoparticles evaluation using functional optical coherence tomography
PublicationThe main object of this research was to assess the ability to characterize the gold nanoparticles using optical modalities like optical coherence tomography. Since the nanoparticles, especially gold one, have been very attractive for medical diagnosis and treatment the amount of research activities have been growing rapidly. The nanoparticles designed for different applications like contrast agents or drugs delivery change the...
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Electromagnetic Simulation with 3D FEM for Design Automation in 5G Era
PublicationElectromagnetic simulation and electronic design automation (EDA) play an important role in the design of 5G antennas and radio chips. The simulation challenges include electromagnetic effects and long simulation time and this paper focuses on simulation software based on finite-element method (FEM). The state-of-the-art EDA software using novel computational techniques based on FEM can not only accelerate numerical analysis, but...
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Remote communication in Scrum teams - a COVID-19 preventive measure or work time optimisation?
PublicationThe article presents the impact of remote work, resulting from the COVID-19 pandemic, on the functioning of Scrum teams. Attempts have been made to analyse the positive and negative aspects of remote work. The article also looks at the impact of remote work on the level of communication and efficiency of Scrum teams. For this purpose, the author conducted research on a sample of 40 organisations that declared to use Scrum methodology,...
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Numeryczna analiza dynamiczna wieszaków w łukowym wiadukcie kolejowym. Analiza przypadku
PublicationW artykule przedstawiono analizę dynamiczną wiaduktu kolejowego w ciągu Centralnej Magistrali Kolejowej zlokalizowanego koło Huty Zawadzkiej. W analizie zwrócono szczególną uwagę na lokalną odpowiedź wieszaków na obciążenie przejeżdżającym pociągiem oraz wiatrem. Obliczenia przeprowadzono na podstawie wykonanego modelu MES. Zweryfikowano poprawność modelu poprzez porównanie uzyskanych wyników z wartościami pomierzonymi. Przeprowadzono...
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Organic Rankine cycle as bottoming cycle to a combined Brayton and Clausius - Rankine cycle
PublicationA preliminary evaluation has been made of a possibility of bottoming of a conventional Brayton cycle cooperating with the CHP power plant with the organic Rankine cycle installation. Such solution contributes to the possibility of annual operation of that power plant, except of operation only in periods when there is a demand for the heat. Additional benefit would be the fact that an optimized backpressure steam cycle has the advantage...
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Video analytics-based algorithm for monitoring egress from buildings
PublicationA concept and a practical implementation of the algorithm for detecting of potentially dangerous situations related to crowding in passages is presented. An example of such a situation is a crush which may be caused by an obstructed pedestrian pathway. The surveillance video camera signal analysis performed in the online mode is employed in order to detect hold-ups near bottlenecks like doorways or staircases. The details of the...
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Visual Data Encryption for Privacy Enhancement in Surveillance Systems
PublicationIn this paper a methodology for employing reversible visual encryption of data is proposed. The developed algorithms are focused on privacy enhancement in distributed surveillance architectures. First, motivation of the study performed and a short review of preexisting methods of privacy enhancement are presented. The algorithmic background, system architecture along with a solution for anonymization of sensitive regions of interest...
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COMPREHENSIVE MODELLING OF THE COST EFFECTIVNESS OF RAILWAY LINE ELECTRIFICATION
PublicationSubject of this paper is the mathematical model estimating the Economical threshold between usage of combustion engine traction and electrical traction for new and modernized railway passenger communication lines. Currently available models do not coincide with the whole complexity of the problem. The proposed model was implemented into Matlab and then validated on “Pomorska Kolej Metropolitalna” investment time-frame and its cost...
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Performance evaluation and model-based optimization of the mainstream deammonification in an integrated fixed-film activated sludge reactor
PublicationThis study aimed to model and optimize mainstream deammonification in an integrated fixed-film activated sludge (IFAS) pilot plant under natural seasonal temperature variations. The effect of gradually decreasing temperature on the performance was evaluated during a winter season and a transition period to summer conditions, and the correlation of the performance parameters was investigated using principal component analysis (PCA)....
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Surface-Protected High-Efficiency Nanophosphors via Space-Limited Ship-in-a-Bottle Synthesis for Broadband Near-Infrared Mini-Light-Emitting Diodes
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High efficiency protocol of DNA extraction from Micromys minutus mandibles from owl pellets: a tool for molecular research of cryptic mammal species
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LSD1-, EDS1- and PAD4-dependent conditional correlation among salicylic acid, hydrogen peroxide, water use efficiency and seed yield inArabidopsis thaliana
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Effect of band gap on power conversion efficiency of single-junction semiconductor photovoltaic cells under white light phosphor-based LED illumination
PublicationOn the basis of the detailed balance principle, curves of efficiency limit of single-junction photovoltaic cells at warm and cool white light phosphor-based LED bulbs with luminous efficacy exceeding 100 lm/W have been simulated. The effect of energy band gap and illuminance on the efficiencies at warm and cool light is discussed. The simulations carried out show that maximum power conversion efficiency at 1000 lx reaches 52.0%...
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The influence of the size of a one-faced metallic head in Janus nanoparticles as a co-catalyst on the photocatalytic efficiency of hydrogen evolution under vis light irradiation
PublicationJanus nanoparticles (NPs) consisting of MoOxSy nanospheres and silver (Ag) head, successfully developed by a simple, controlled method were in the first time they were applied as a co-catalysts in photocatalytic hydrogen generation reaction under vis light irradiation (λ > 420 nm). The MoOxSy-Ag as a co-catalysts were deposited on the obtained ZnIn2S4 microspheres (ZIS) using physical absorption method. The influence of the size...
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MicroGal Gravity Measurements with MGS-6 Micro-g LaCoste Gravimeter
PublicationKnowing the exact number of fruit and trees helps growers to make better decisions about how to manage their production in the orchard and prevent plant diseases. The current practice of yield estimation is to manually count fruit or flowers (before harvesting), which is a very time-consuming and costly process. Moreover it’s not practical for large orchards. It also doesn’t allow to make predictions of plant development in a more...
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Interrelationship between total volatile organic compounds emissions, structure and properties of natural rubber/polycaprolactone bio-blends cross-linked with peroxides
PublicationNatural rubber/polycaprolactone (NR/PCL) bio-based blends with different organic peroxides were prepared using an internal batch mixer and subsequently cross-linked at 170°C. Two types of commonly used organic peroxides, dicumyl peroxide and di(tert-butylperoxyisopropyl)benzene peroxide, were applied as free-radical initiator. Cross-linking efficiency of NR/PCL blends were investigated using oscillating disc rheometer measurements,...
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Changes in the addiction prevalence in Polish population between 1990-2019: Review of available data
PublicationThe 1989 collapse of the socialist political system in Poland initiated an avalanche of modifications regarding healthcare policy resulting with new institutions and programs dedicated to monitoring and preventing addiction. In the current article, we look at the available data allowing to track changes in (1) the prevalence of exposure to addictive substances and behaviors, and (2) changes of addictions prevalence in Poland...
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Assessing Tram Infrastructure Safety Using the Example of the City of Gdańsk
PublicationAnalysis of Gdańsk’s tram network statistics shows that incidents are quite frequent (about 650 within 5 years) and mostly involve collisions and crashes. As well as reducing the tram systems’ efficiency and reliability, incidents have a nega-tive effect on road safety. As Polish cities extend their tram networks, they must also ensure that their existing networks are safe. This is to be achieved by conducting safety assessments....
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A New Type of Macro-Elements for Efficient Two-Dimensional FEM Analysis
PublicationThis letter deals with a model order reduction technique applicable for driven and eigenvalue problems solved using the finite element method (FEM). It allows one to efficiently compute electromagnetic parameters of structures comprising small features that require strong local mesh refinement. The subdomains of very fine mesh are separated from the global domain as so called macro-elements that undergo model reduction. The macro-elements...
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Towards Designing an Innovative Industrial Fan: Developing Regression and Neural Models Based on Remote Mass Measurements
PublicationThis article presents the process of the construction and testing a remote, fully autonomous system for measuring the operational parameters of fans. The measurement results obtained made it possible to create and verify mathematical models using linear regression and neural networks. The process was implemented as part of the first stage of an innovative project. The article presents detailed steps of constructing a system to...
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Comparison analysis of selected nuclear power plants supplied with helium from high-temperature gas-cooled reactor
PublicationThe article presents results of efficiency calculations for two 560 MW nuclear cycles with high-temperature gas-cooled reactor (HTGR). An assumption was made that systems of this type can be used in so-called marine nuclear power plants. The first analysed system is the nuclear steam power plant. For the steam cycle, the efficiency calculations were performed with the code DIAGAR, which is dedicated for analysing this type of systems....
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Highly Active TiO2 Microspheres Formation in the Presence of Ethylammonium Nitrate Ionic Liquid
PublicationSpherical microparticles of TiO2 were synthesized by the ionic liquid-assisted solvothermal method at different reaction times (3, 6, 12, and 24 h). The properties of the prepared photocatalysts were investigated by means of UV-VIS diffuse-reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET) surface area measurements, scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy...
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Utilisation of waste heat from the power plant by use of the ORC aided with bleed steam and extra source of heat
PublicationUtilization of waste heat recovered from the exhaust gases of the power generation unit by means of ORC (organic Rankine cycles) installation is considered. The waste heat is available in the form of a stream of hot water having temperature of 90 stC in the amount of 200 MWt. To increase evaporation temperaturę of ORC working fluid the heat of steam from the extraction points from the low-pressure part of steam turbine is used....
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FTIR spectroscopic and thermogravimetric characterization of ground tyre rubber devulcanized by microwave treatment
PublicationIn this work, the phenomena involved in the microwave devulcanization of ground tyre rubber (GTR) were investigated. Three types of GTR with different content of organic compounds (elastomers, plasticizers, etc.), carbon black and ash have been studied. The chemical structure of GTR before and after a microwave devulcanization process was analyzed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)...
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Comprehensive comparison of compact UWB antenna performance by means of multi-objective optimization
PublicationAn optimization-based procedure for comprehensive performance comparison of alternative compact UWB antenna topologies is discussed. The assessment of the antenna performance is conducted with respect to the structure size and its reflection response. More specifically, the best possible tradeoffs between these two figures of merit are identified through multiobjective optimization at the level...
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Application of Vertical Reed Beds as a Buffer for Effluent from SBR ANAMMOX Treatment for Reject Water from Centrifugation
PublicationThe main purpose of this study is to determine the removal efficiency of nitrogen compounds in the effluentfrom ANAMMOX process used to treat reject water after centrifugation. A pilot model was bulit consisting of fourdifferent Treatment Wetlands beds with different filter substrate and with or without macrophytes growth. Verticalsubsurface flow type filters have been choosen thanks to their highest efficiency in NH4-N removal...
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Comparative analysis of the theoretical models of ideal propulsor, ideal fluid brake, ideal screw propeller and ideal axial wind turbine
PublicationThe article presents a detailed discussion of four different fluid dynamics devices.These devices are presented with all relevant mathematical formulae regarding the forces, the power and the efficiency. It is demonstrated that application of the Betz theorem to axial wind turbines is not correct and it underestimates the maximujm achievable efficiency. This conclusion is supported by numerical calculations.
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NIEKONWENCJONALNE BADANIA SKUTECZNOŚCI HAMOWANIA W STACJI KONTROLI POJAZDÓW
PublicationW artykule przedstawiono niekonwencjonalne badania skuteczności hamowania samochodu na stanowisku diagnostyczny. Na podstawie przeprowadzonych badań określono wpływ ciężaru samochodu na skuteczność hamowania. Dokonano analizy porównania zmierzonego wskaźnika skuteczności hamowania i rzeczywistego wskaźnika skuteczności hamowania dla różnego obciążenia samochodu użytego do badań.
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Leszek Jarzębowicz dr hab. inż.
PeopleLeszek Jarzebowicz received the M.Sc., Ph.D. and D.Sc. degrees from Gdansk University of Technology (GUT), Poland, in 2005, 2010 and 2019, respectively. His research areas include control and modeling of electric drives, diagnostics of railway vehicles, analysis of energy efficiency in electrified transport, and microprocessor implementation of control algorithms. His teaching interests focus on electric vehicles, electrical engineering...
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Application analysis of a hybrid solid oxide fuel cell-gas turbine system for marine power plants
PublicationThe results of theoretical studies of the possibilities of using hybrid solid oxide fuel cell–gas turbine (SOFC-GT) systems for marine power plants are presented. A 500 kW auxiliary marine power plant scheme using stacks of SOFCs in combination with a regenerative gas turbine operating with over-expansion based on our recent patent application is proposed. The results of mathematical modelling showed the opportunity to obtain a...
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Numerical analysis of CO2-water separation in a horizontal double T-junction
PublicationCarbon dioxide is considered one of the main factors leading to global warming. Considering the significant impacts of CO2 on climate change, various technologies have been developed in recent decades to control carbon emission, such as for example CO2 capture and storage. The developed cycle of a negative CO2 emission power plant includes some devices, out of which, separator plays an indispensable role. To this end, T-junction...
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X-ray Photoelectron Spectroscopy of Carboxylic Acids as Corrosion Inhibitors of Aluminium Alloys
PublicationThe datasets, titled X-ray Photoelectron Spectroscopy studies of citric acid adsorption on aluminium alloy 5754 in alkaline media and X-ray Photoelectron Spectroscopy studies of various carboxylic acids adsorption on aluminium alloys in alkaline media, contain XPS studies of the corrosion inhibitory action of selected dicarboxylic acids towards commercially available aluminium alloy 5754 in alkaline media at pH=11. These datasets...
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Music Data Processing and Mining in Large Databases for Active Media
PublicationThe aim of this paper was to investigate the problem of music data processing and mining in large databases. Tests were performed on a large data-base that included approximately 30000 audio files divided into 11 classes cor-responding to music genres with different cardinalities. Every audio file was de-scribed by a 173-element feature vector. To reduce the dimensionality of data the Principal Component Analysis (PCA) with variable...
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Video Analytics-Based Algorithm for Monitoring Egress from Buildings
PublicationA concept and practical implementation of the algorithm for detecting of potentially dangerous situations of crowding in passages is presented. An example of such situation is a crush which may be caused by obstructed pedestrian pathway. Surveillance video camera signal analysis performed on line is employed in order to detect hold-ups near bottlenecks like doorways or staircases. The details of implemented algorithm which uses...
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Excitation of Circularly Polarized Wave via Single-Feed Metasurface-Integrated Compact Antenna for Internet of Things
PublicationA compact circularly polarized (CP) quasi-omnidirectional antenna is introduced for internet of things (IoT). The structure consists of two components implemented on FR-4 substrates, and sep-arated by an air gap: one printed with a rectangular patch fed through a matching network, and another with a metasurface and a ground plane. Two different methods for impedance matching are employed. An equivalent circuit model of the antenna...
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Wartości rekomendowane wskaźników sprawności działania dla przedsiębiorstw z sektora MSP
PublicationNiniejszy artykuł poświęcony jest zagadnieniu sprawności działania małych i średnich przedsiębiorstw. W trakcie przeprowadzonych badań wykorzystano 34 820 sprawozdania finansowe przedsiębiorstw. Dla potwierdzenia zróżnicowania sprawności działania w zależności od przynależności sektorowej przedsiębiorstwa wykorzystano test nieparametryczny Kruskala – Wallisa. Zawarte w artykule wyniki badań dowodzą, że MSP należące do różnych działów...
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Impact of Tetrazolium Ionic Liquid Thermal Decomposition in Solvothermal Reaction on the Remarkable Photocatalytic Properties of TiO2 Particles
PublicationIonic liquids (ILs) could serve as a structuring agent, a solvent, or a source of dopant during solvothermal synthesis of semiconductors particles. To understand the role of IL during formation of TiO2 particles, it is necessary to study the stability of this IL in solvothermal synthesis conditions, as well as studying the surface properties of formed TiO2 particles. In view of this, the effect of the 2,3,5-triphenyltetrazolium...
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Corporate Governance and Ownership Structure in the Top 30 Listed Non Financial Companies in Poland
PublicationThis paper offers a first analysis of the relationships between corporate governance models and rules and ownership structure of the top 30 Polish firms listed at the WSE (not considering foreign firms and/or the Polish branches of foreign firms listed at the same stock exchange, nor the financial companies and the banks). The general picture depicted by this analysis is putting into evidence the increasing importance of institutional...
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Exploring DAD and ADD Methods for Dealing with Urban Heat Island Effect
PublicationThe Urban Heat Island (UHI) effect in the context of climate change and temperature fluctuations is an increasing challenge for contemporary cities. Numerous activities focus on mitigation and adaptation to the UHI effect using both appropriately selected design strategies and technological solutions. However, not all of these technologies support the postulates of ecological and low-carbon cities. Their design, implementation,...
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Structural Adaptive, Self-Separating Material for Removing Ibuprofen from Waters and Sewage
Publication-cyclodextrin nanosponge (CDM) was used for the adsorption of ibuprofen (IBU) from water and sewage. The obtained material was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), Barrett– Joyner–Halenda (BJH), Harkins and Jura t-Plot, zeta potential, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elementary analysis (EA)....
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Application of the Heavy-Atom Effect for (Sub)microsecond Thermally Activated Delayed Fluorescence and an All-Organic Light-Emitting Device with Low-Efficiency Roll-off
PublicationThefeatureof abundantandenvironmentallyfriendlyheavyatoms(HAs)like bromineto acceleratespin-forbiddentransitionsin organicmoleculeshas beenknownforyears.In combinationwiththe easinessof incorporation,brominederivativesof organicemittersshowingthermallyactivateddelayedfluorescence(TADF)emergeas a cheapand efficientsolutionforthe slowreverseintersystemcrossing(rISC)problemin suchemittersand strongefficiencyroll-offof all-organiclight-emittingdiodes(OLEDs).Here,we...
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Combination of air-dispersion cathode with sacrificial iron anode generating Fe2+Fe3+2O4 nanostructures to degrade paracetamol under ultrasonic irradiation
PublicationIn the present study, ultrasound (US) was coupled with an electrochemical process (ECP) consisting of a novel cathode of carbon cloth (CC)-carbon black (CB) as the nano-composite air-dispersion cathode (NADC) for the degradation of paracetamol (APAP) in an aquatic medium. The NADC favored in situ production of H2O2 by the cathodic reduction. The implementation of iron sacrificial anode instead of dimensionally stable anodes resulted...
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Analiza skuteczności wybranych strategii kontrariańskich na warszawskiej GPW w latach 2014–2018
PublicationCapital multiplication is the main goal of investors and for many years they have been looking for methods and strategies that would enable them to achieve it to the greatest possible extent. Due to the fact that the expectations and characteristics of investors, including those concerning the investment period, are diverse, multiple strategies have emerged. One of such strategies, mainly long-term in nature, is the so-called...
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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...