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Search results for: COMMON CAUSE FAILURES
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Photovoltaic demonstration set up
PublicationThe use of photovoltaics is growing rapidly in the industry as well as households. Therefore, educating the public will help them understand solar cell technology, which is becoming more common in everyday life. This paper proposes a demonstrational set-up of photovoltaic panel for the purpose of science education. It was used in numerous outreach activities such as science fairs. Moreover, it proved to be a great tool for education...
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Low voltage photovoltaic power system
PublicationThe use of photovoltaics is growing rapidly in the industry as well as households. Therefore, educating the public will help them understand solar cell technology, which is becoming more common in everyday life. This paper proposes a demonstrational set-up of photovoltaic panel for the purpose of science education. It was used in numerous outreach activities such as science fairs. Moreover, it proved to be a great tool for education...
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Stakeholders Satisfaction Index as an Important Factor of Improving Quality Management Systems of Universities in Poland Stakeholders Satisfaction
PublicationThe following article analyses selected methods of assessing the quality of educational services of universities and discusses the role of stakeholders in, required by law, quality assurance and quality management systems according to Common Assessment Framework for education. Furthermore, it presents the Stakeholders Satisfaction Index (SSI) which is an original proposal of an aggregate measure of satisfaction perceived by stakeholders....
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Identification of pollutants at the adjacent areas to the landfill site using two dimensional gas chromatography with mass spectrometry technique
PublicationMunicipal landfills are considered one of the main sources of air pollutants. In this article is presented the use of a modern analytical technique: a two dimensional gas chromatography to identify the substances in the atmospheric air near a waste processing plant located in Gdansk. In order to determine the types of substances occurring in different atmospheric conditions, the study was conducted from February to April 2016....
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Complexes of silanethiolate ligands: Synthesis, structure, properties and application
PublicationThe purposeful syntheses of silanethiolate complexes started approximately in the mid-eighties of the 20th century but no summary of the synthetic efforts has been reported till now. The synthetic methods and the resulting complexes have some common features, which are emphasized throughout the review. Thereby specific difficulties during synthesis are outlined and the structures, properties and possible applications of the resulting...
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New type T-Source inverter
PublicationThis paper presents different topologies of voltage inverters with alternative input LC networks. The basic topology is known in the literature as a Z-source inverter (ZSI). Alternative passive networks were named by the authors as T-sources. T-source inverter has fewer reactive components in comparison to conventional Z-source inverter. The most significant advantage of the T-source inverter (TSI) is its use of a common voltage...
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The equivariant spectral flow and bifurcation of periodic solutions of Hamiltonian systems
PublicationWe define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ring of the latter. This G-equivariant spectral flow shares all common properties of the integer valued classical spectral flow, and it can be non-trivial even if the classical spectral flow vanishes. Our main theorem uses the G-equivariant spectral flow...
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Pier of the future- investigation of green and blue strategies as tools for modernization of Gdynia's public waterfront
PublicationBetween rising water levels and global migration to cities, architects and designers need to critically reimagine the relationship between coastal landscapes and public space. Cities are facing entirely new risks and environmental conditions. Resiliency, infrastructure, and ecology are increasingly common terms, reflecting the growing demand to address the spatial and formal challenges faced by cities worldwide. Rethinking boundaries...
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Interactions between polyphenolic antioxidants quercetin and naringenin dictate the distinctive redox-related chemical and biological behaviour of their mixtures
PublicationFood synergy concept is suggested to explain observations that isolated antioxidants are less bioactive than real foods containing them. However, mechanisms behind this discrepancy were hardly studied. Here, we demonstrate the profound impact of interactions between two common food flavonoids (individual: aglycones quercetin—Q and naringenin—N− or their glycosides rutin—R and naringin—N+ vs. mixed: QN− and RN+) on their electrochemical...
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Diaryl Sulfide Derivatives as Potential Iron Corrosion Inhibitors: A Computational Study
PublicationThe present work aimed to assess six diaryl sulfide derivatives as potential corrosion inhibitors. These derivatives were compared with dapsone (4,4′-diaminodiphenyl sulfone), a common leprosy antibiotic that has been shown to resist the corrosion of mild steel in acidic media with a corrosion efficiency exceeding 90%. Since all the studied compounds possess a common molecular backbone (diphenyl sulfide), dapsone was taken as the...
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Conservation and diversity of MutS proteins
PublicationThe homologues of MutS, mismatch repair protein, exist in all prokaryotes, with the exception of Actinobacteria, Mollicutes and part of the Archaea. Multiple alignments of 316 MutS amino acid sequences from 169 species revealed conserved residues and sequence motifs distinguishing MutS homologues. All MutS homologues show high conservation within the ATPase domain. MutS1, the homologue responsible for DNA mismatch recognition,...
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Analysis of the instantaneous power signal for bearing diagnostics - bearing undamaged
Open Research DataThe attached dataset contains the measurement results of the instantaneous values of current and voltage, recorded during the diagnostics of an undamaged bearing. Bearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous...
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The Use of Sensory Analysis Techniques to Assess the Quality of Indoor Air
PublicationThe quality of indoor air is one of the significant elements that influences people's well-being and health inside buildings. Emissions of pollutants, which may cause odor nuisance, are the main reason for people's complaints regarding the quality of indoor air. As a result, it is necessary to perform tests aimed at identifying the sources of odors inside buildings. The article contains basic information on the characteristics...
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A recent developments in polyurethane foams containing a low-cost and pro-ecological modifiers
PublicationDiversity of the polyurethane (PU) foams applications cause that investigation of the relationships between their structure and properties is currently very popular topic among the many research institutions and companies. At the turn of the last years many scientific papers about PU foams and their composites were published. The one of the main research trends in this field is related to the reduction of production costs of...
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Calix[4]arene-Thioamides as Ionophores for Transition and Heavy Metal cations
PublicationCalix[4]arene derivatives play an important role as sensing materials in Ion Selective Electrodes(ISEs). Nowadays a high impact is put to control in natural waters the level of toxic heavy metals, like Pb ,Cd, Hg or Cu which may cause the great risk to human health. Our goal was to design and to synthesize ligands possessing ability to bind transition and heavy metal cations. The synthesis, crystal structures,extractive and ionophoric...
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The influence of high temperature wood drying conditions using air-steam mixture on its properties
PublicationThe results of properties change of beech wood after drying process are presented. The wood taken to experiments was from northern part of Pomeranian region in Poland. Before the main high temperature drying process using air-steam mixture, wood was initially dried in an open air conditions. The high temperature drying process was conducted at temperature 120oC, humidity 48%, flow rate of drying medium 2.5m/s and atmospheric pressure....
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Macro-elements and Model Order Reduction for Efficient Three-Dimensional FEM Analysis
PublicationAn efficient model order reduction (MOR) methodology for three dimensional vector finite element method (FEM) is developed to accelerate simulations of the structures containing features that cause strong variations of mesh density. As the result of presented algorithm, FEM subsystems of equations corresponding to the selected refined region are converted into a very compact sets of linear equations, called macro-elements.Numerical...
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Joanna Czerska dr inż.
PeopleI am a woman whose mission and passion is the development of people and organizations. My motto is: "There is no such fantasy that human will and reason cannot transform into reality." William Shakespeare In my life I am guided by the values of respect, teamwork and a positive attitude. They define me and decide what kind of person I am. My adventure with Lean began when I was writing my diploma thesis during my studies at WZiE...
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Long-term mortality after transcatheter aortic valve implantation for aortic stenosis in immunosuppression-treated patients: a propensity-matched multicentre retrospective registry-based analysis
PublicationIntroduction Data regarding patients with a previous medical record of immunosuppression treatment who have undergone transcatheter aortic valve implantation (TAVI) are limited and extremely inconclusive. Available studies are mostly short term observations; thus there is a lack of evidence on efficacy and safety of TAVI in this specific group of patients. Aim To compare the in-hospital and long-term outcomes between patients...
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Estimation of Stresses in a Dry Sand Layer Tested on Shaking Table
PublicationTheoretical analysis of shaking table experiments, simulating earthquake response of a dry sand layer, is presented. The aim of such experiments is to study seismic-induced compaction of soil and resulting settlements. In order to determine the soil compaction, the cyclic stresses and strains should be calculated first. These stresses are caused by the cyclic horizontal acceleration at the base of soil layer, so it is important...
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Troubleshooting of the determination of bisphenol A at ultra-trace levels by liquid chromatography and tandem mass spectrometry
PublicationDetermination of trace amounts of bisphenol A (BPA) may cause problems mainly related to the presence of BPA in solvents (even in LC-MS grade), laboratory vessels, and plastic equipment used for sample preparation. Variable and sometimes significant amounts of BPA present in the background cause problems in obtaining good repeatability of measurements at the ultra-trace levels. Such observations (i.e., poor repeatability of results)...
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First report of seroprevalence of Toxoplasma gondii infection in sheep in Pomerania, northern Poland
PublicationIntroduction and objective. Toxoplasmosis is parasitic disease which has economic relevance for both veterinary and human medicine. In sheep, toxoplasmosis is a major cause of abortion and can thus cause reproductive problems. The current study aimed to determine the occurrence of anti-Toxoplasma gondii IgG antibodies in sheep from 13 districts of northern Poland and thereby obtain actual data about T. gondii seroprevalence in...
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Effect of Overloaded Vehicles on Whole Life Cycle Cost of Flexible Pavements
PublicationThe phenomenon of vehicle overloading—illegal exceeding of maximum legal weight of vehicles, is a serious problem both in developing and developed countries around the world. Overloaded vehicles occur less frequently in comparison to properly loaded vehicles but due to their greater potential to cause damage they significantly contribute to distress of pavement structure. As studies show, the number of overloaded vehicles increases...
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High-Resolution, Broad-Range Detection Setup for Polarimetric Optical Fiber Sensors
PublicationA common-path polarization interferometer using a Wollaston prism and an area detector for the measurement of retardation or optical path difference is presented. Employing a moderate-resolution 1280 by 1024 pixel monochrome camera, it offers a measurement range of approximately 780 radians at 830 nm and 1350 radians at 515 nm while maintaining a high measurement resolution. Retardation introduced by a zero-order waveplate or a...
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A predictive estimation based control strategy for a quasi-resonant dc-link inverter
PublicationIn this paper the predictive estimation based control strategy for a quasi-resonant dc link inverter (PQRDCLI) is developed. Instead of direct measurement of dc link input inverter current – its estimation with one step prediction is applied. The PQRDCLI fed induction motor, controlled with a predictive current estimation stabilized inverter output voltage slopes independently of load. Moreover, reduction of overvoltage spikes...
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Stakeholders Satisfaction Index as an Important Factor of Improving Quality Management Systems of Universities in Poland
PublicationThe following article analyses the role of stakeholders in selected methods of assessing the quality of educational services of universities and discusses quality management systems according to Common Assessment Framework for education. Furthermore, it presents the example of method of stakeholder satisfaction measurement called Stakeholders Satisfaction Index (SSI) which is an original proposal of an aggregate measure of satisfaction...
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Investigation of abdomen surface deformation due to life excitation: implications for implant selection and orientation in laparoscopic ventral hernia repair
PublicationVentral hernia is a common medical problem. Statistically there are around 10% recurrences of the sickness. The authors' former investigation proved edges of the hernia orifice displacements to be one of the factors causing recurrence. Thus, experimental investigation of the abdomen surface deformation due to some normal activities of people is studied.The extreme strains, their localization and directions are identified. The acquired...
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Entrepreneurship after the Age of Sixty–Five? Reflections of Third Age University students
PublicationThe common synonyms for entrepreneurship usually include such concepts as creativity, innovation, and activity. These, in turn, are more often associated with youth rather than people of older age (Górniak, 2013). On the basis of literature research and interviews conducted with students from the Sopot School of Social Psychology of the University of the Third Age, the authors determined that among individuals...
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Numerical modal analysis of a vertical rising steel water gate
PublicationVertical rising steel water gates are very common not only in Poland and Germany but also in other countries of the world. Their popularity is mainly attributed to their simplicity of construction, which makes their production process cheaper and faster when compared to other solutions. The aim of this paper is to conduct a numerical modal analysis to examine the eigenvalues and eigenmodes of a vertical rising steel gate. Two cases...
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Numerical Studies on Propellers in Open Water and behind Hulls aiming to support the Evaluation of Propulsion Tests
PublicationA RANS based numerical analysis of propellers can contribute considerably to our understanding of propeller/hull interaction. It may also allow for a review of scaling procedures on results from experimental fluid dynamics (EFD). Using various RANS codes (Fluent, CFX, STAR-CCM+ and FreSCo+) on common test cases the authors first focused on propeller open water (POW) calculations. Next we simulated the propeller hull interaction...
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Determination of leakage inductances of multi-winding and single-phase transformer
PublicationThis paper presents the method for determination of leakage inductances of single-phase and multi-winding transformer. The matrix of leakage inductances takes into account leakage self and also leakage mutual magnetic couplings. It is assumed that there is a flux common to all windings and several leakage fluxes referred to a particular winding. The flux linkages of each coil needed fo calculation of leakage inductances was computed...
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3D PCB package for GaN inverter leg with low EMC feature
PublicationThis paper presents the adaptation of a 3D integration concept previously used with vertical devices to lateral GaN devices. This 3D integration allows to reduce loop inductance, to ensure more symmetrical design with especially limited Common Mode emission, thanks to a low middle point stray capacitance. This reduction has been achieved by both working on the power layout and including a specific shield between the devices and...
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Tax Policy Tools of Selected European Countries as a Mechanism for Counteracting the Effects of the Crisis Caused by the COVID-19 Disease Pandemic
PublicationCrises play an important role in a economics life. They are common and it is impossible to omit them. This following study investigates the concept of ‘crisis’ in the context of economic situation. This text describes the most important financial crises that took place in the past. After that authors passes on a detailed analysis of the actual corona-crisis and the way that it affects the economy globally. The main goal of this...
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Multiple jets impingement – numerical analysis by the ζ-f and hybrid VLES turbulence models
PublicationPresented paper summarizes the Authors findings referring to the numerical analyses of the jet impinging phenomena in the case of complex jets configurations in various applications e.g. in the heat exchangers. Multiple jets interference resulting in the cross-flow and the surface curvature are the factors which impose the need of advanced turbulence models utilization. The outcome of the research based on the ζ-f turbulence model...
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Analiza symulacyjna wybranych algorytmów dostarczania paczek wiadomości w sieci DTN na Bałtyku
PublicationJedną z dróg zwiększania bezpieczeństwa żeglugi morskiej jest zapewnienie powszechnej dostępności usług e-nawigacji na obszarach morskich pozbawionych dostępu do Internetu. W artykule opisano wyniki symulacji wybranych algorytmów przekazywania wiadomości usług niewrażliwych na opóźnienia w znacznej odległości od lądu, w sieci o nieciągłej i sporadycznej łączności.
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NARAŻENIA NAPIĘCIOWE SILNIKÓW INDUKCYJNYCH ZASILANYCH Z FALOWNIKÓW NAPIĘCIA
PublicationW artykule przedstawiono zagadnienia związane z narażeniami izolacji silników pracujących w układach napędowych z falownikami napięcia. Znaczne stromości napięć oraz zjawiska falowe w przewodach zasilających powodują przyspieszoną degradacje izolacji maszyn. Rozwiązaniem jest stosowanie filtrów biernych na wyjściu falownika.
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Exploring the Solubility Limits of Edaravone in Neat Solvents and Binary Mixtures: Experimental and Machine Learning Study
PublicationThis study explores the edaravone solubility space encompassing both neat and binary dissolution media. Efforts were made to reveal the inherent concentration limits of common pure and mixed solvents. For this purpose, the published solubility data of the title drug were scrupulously inspected and cured, which made the dataset consistent and coherent. However, the lack of some important types of solvents in the collection called...
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The influence of electromagnetic pollution on living organisms – historical trends and forecasting changes
PublicationCurrent technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. Wireless and radio communication, electric power transmission or devices in daily use such as smartphones, tablets and portable computers every day expose people...
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Authenticity of Architectural Heritage in a Rebuilt City. Comments to Vaclav Havel’s Impression after His Visit in Gdansk in 2005
PublicationThere is no doubt that authenticity is a cardinal feature of architectural heritage and should be protected in the same way as historical and cultural value of monuments or their integrity. Sometimes, one decides to reconstruct a destroyed historical building due to important emotional, scientific, artistic or political reasons (e.g. the Zwinger Palace in Dresden or the Royal Castle in Warsaw). However, the solution which should...
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A Five-Leg Three-Level Dual-Output Inverter
PublicationClassical 3-level dual-output inverter, 3-L DOI, involves two similar 3-level inverters that provides a pair of 3-phase output voltages with same or different frequencies from common input voltage source. Flexibility of either operation of the constituting inverters is evident in this DOI; but total duplication of power switches is a major drawback. State of the art coupled 3-L DOIs reduce this drawback by providing series-shared...
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Supply current signal and artificial neural networks in the induction motor bearings diagnostics
PublicationThis paper contains research results of the diagnostics of induction motor bearings based on measurement of the supply current with usage of artificial neural networks. Bearing failure amount is greater than 40% of all engine failures, which makes their damage-free operation crucial. Tests were performed on motors with intentionally made bearings defects. Chapter 2 introduces the concept of artificial neural networks. It presents...
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BeesyBees: A mobile agent-based middleware for a reliable and secure execution of service-based workflow applications in BeesyCluster
PublicationIntegrating distributed services into workflows comes with its own set of challenges, including security, coordination, fault tolerance and optimisation of execution time. This paper presents an architecture and implementation - nicknamed BeesyBees - that allows distributed execution of workflow applications in BeesyCluster using agents. BeesyCluster is a middleware that allows users to access distributed resources as well as publish...
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Polymer journal bearings behaviour research under limited lubrication and cooling conditions conducted on high torque test rig
PublicationPolymer journal bearings are frequently used as a water-lubricated bearings of small marine units’ propeller shafts . Choice of these bearings is based on their simple construction and relatively low purchase and maintenance costs. Although properly designed and installed water lubricated bearings may well last for over a decade, rapid wear or failure of these bearings can be observed...
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Experiences and Challenges in Fatality Reduction on Polish Roads
PublicationAccording to the UN, road safety is the key to achieving sustainable development goals, yet the complexity of how road accidents happen makes this a difficult challenge leaving many countries struggling with the problem. For years, Poland has infamously been one of the EU’s top countries for road-accident fatality rates. Despite that, it has made significant progress in the last thirty years with a fatality reduction of more than...
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Effect of User Mobility upon Trust Building among Autonomous Content Routers in an Information-Centric Network
PublicationThe capability of proactive in-network caching and sharing of content is one of the most important features of an informationcentric network (ICN). We describe an ICN model featuring autonomous agents controlling the content routers. Such agents are unlikely to share cached content with other agents without an incentive to do so. To stimulate cooperation between agents, we adopt a reputation and trust building scheme that is able...
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Detection of ferromagnetic objects in local magnetic anomaly of the Baltic Sea
PublicationIn geological researches several kinds of methods are applied to discovering the natural resources. Planes, helicopters and UAVs (UnmAnned Vehicle) are used in researches in large areas. The gravity, electromagnetic and magnetic methods, which are used in geological researches, are presented in this paper. The special attention was paid to magnetic systems installed on mobile platforms. The magnetic field of the Earth obtained...
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A city and a wind farm. Landscape perspective
PublicationThe aim of the paper is to present the problems of the location of the wind farms in close neighbourhood to the historical cities, and the ways to minimize the potential landscape threats. The production of clean energy is obligatory in EU. In spite of how positive to the environment the wind energy production is, it may cause negative effects. The results of landscape studies of two towns in Poland prove that the location of such...
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Applicability of null-steering for spoofing mitigation in civilian GPS
PublicationCivilian GPS signals are currently used in many critical applications, such as precise timing for power grids and telecommunication networks. Spoofing may cause their improper functioning. It is a threat which emerges with the growing availability of GPS constellation simulators and other devices which may be used to perform such attack. Development of the effective countermeasures, covering detection and mitigation, is necessary...
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Inhibition of the granular anammox process by the high concentration of free ammonia.
PublicationHigh concentrations of ammonia and nitrite, typical for reject water treatment in the anammox process with the use of high temperatures and pH, may cause free ammonia (FA) inhibition. In this study, the inhibitory effect of FA on anammox process rate was investigated in a bench-scale sequencing batch reactor (SBR) with granular anammox biomass. Results of the study present that the anammox process could be successfully operated...
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CM Voltage Compensators for Power Electronic Interfaces
PublicationThe experimental results presented in the paper have shown that the application of the PEIs might cause EMC related problems, especially in the case of the application of a group of connected converters. The most convenient way to reduce EMI currents and prevent aggregation of EMI currents introduced by a group of converters is through passive compensation of voltage interference sources inside of the single converters. In the...