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Search results for: TECHNICAL REQUIREMENTS AND OPERATING RANGE OF PHOTOVOLTAIC POWER PLANTS
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Conjugated control of triple active bridge converter with common HFT
PublicationPaper presents synthetic analyses of single input, dual output DC/AC/DC converter with common high frequency transformer. Rise the problem of cross-coupling power flows between secondary terminals, under asymmetrical control operating condition. It also proposes a new approach to converter control, based on conjugated phase shift modulation and defines its limitations. Finally, the developed control technique was verified by simulation...
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Propagation Characteristics of Partial Discharges in an Oil-Filled Power Transformer
PublicationPower transformers are among the most important assets in the power transmission and distribution grid. However, they suffer from degradation and possible faults causing major electrical and financial losses. Partial discharges (PDs) are used to identify the insulation health status and their degradation level. PDs are incipient, low-magnitude faults caused by localized dielectric breakdown. Those activities emit signals in many...
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Digital microcontroller for sonar waveform generator
PublicationGenerating sounding signals is essential for the operation of active sonar. The system should be highly reliable. This can be achieved through architecture, communication between the devices, and a well-designed and self–testing software. The system presented in the article is responsible for the generation of hydroacoustic sounding signals, and ensures proper interaction between power amplifiers and power supplies. Thanks to its...
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Potential of Silver Nanoparticles in Overcoming the Intrinsic Resistance of Pseudomonas aeruginosa to Secondary Metabolites from Carnivorous Plants
PublicationCarnivorous plants are exemplary natural sources of secondary metabolites with biological activity. However, the therapeutic antimicrobial potential of these compounds is limited due to intrinsic resistance of selected bacterial pathogens, among which Pseudomonas aeruginosa represents an extreme example. The objective of the study was to overcome the intrinsic resistance of P. aeruginosa by combining silver nanoparticles (AgNPs)...
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BINDER COURSES USING COLD RECYCLED MIXTURES – A NOVEL CONCEPT IN COLD RECYCLING
PublicationCold recycling with cement and bituminous emulsion is one of the most environmentally friendly techniques to maximize the reuse of reclaimed asphalt (RA) collected during demolition of roads. Cold recycled mixtures are commonly used for base courses in construction or rehabilitation of flexible and semi-rigid pavements. Current experiences demonstrated that cold recycling with appropriate requirements and technical recommendations...
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Power System Stabilizer as a Part of a Generator MPC Adaptive Predictive Control System
PublicationIn this paper, a model predictive controller based on a generator model for prediction purposes is proposed to replace a standard generator controller with a stabilizer of a power system. Such a local controller utilizes an input-output model of the system taking into consideration not only a generator voltage Ug but also an additional, auxiliary signal (e.g., α, Pg, or ωg). This additional piece of information allows for taking...
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Analysis of energy efficiency of suburban railway transport network
PublicationRising numbers of agglomeration residents cause increased need for people movement on daily basis. Because of congestion of local roads, air pollution and limited parking space, providing mass transit based on electric traction is reasonable. While the electric rail vehicles are considered highly efficient in themselves, they need to be analyzed as a part of a transport network, because energy consumption depends on operating conditions...
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Chemical Theory of Machines, basic principles of strength with examples of calculations
PublicationThis book encompasses the essential range of information on technical aspects of mechanical design. It was written primarily for the students and staff of chemistry faculties of technical universities, yet it may also be utilized by everyone, who ether would like to try or already enjoys designing, but cannot take advantage of typical stress & machine construction handbooks. These handbooks often require familiarity with the concepts...
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Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
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Highly-Miniaturized Self-Quadruplexing Antenna Based on Substrate-Integrated Rectangular Cavity
PublicationThis paper introduces a novel self-quadruplexing antenna (SQA) architecture using a substrate-integrated rectangular cavity (SIRC) for compact size, wide-frequency re-designability, and high isolation responses. The proposed SQA is developed by engraving two U-shaped slots (USSs) on the top conductor of the SIRC. The USSs are excited by employing four microstrip feedlines to achieve self-quadruplexing antenna characteristics. The...
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Design of microstrip antenna subarrays: a simulation-driven surrogate-based approach
PublicationA methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (here, a corporate network) on the subarray side-lobe level and allows adjustment of both radiation and reflection responses of the structure under design within a single automated process. This process is realized as surrogate-based optimization that produces...
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Simulation-Driven Design of Microstrip Antenna Subarrays
PublicationA methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (e.g., a corporate network) on the subarray side lobe level and allows adjusting both radiation and reflection responses of the structure under design within a single automated process. This process is realized as surrogate-based optimization that produces designs...
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Współczynniki strat energetycznych w elementach napędu hydrostatycznego
PublicationW każdym układzie napędowym należy zastąpić obraz przepływu mocy opisany dotychczas powszechnie stosowanym wykresem Sankey’a spadku mocy zgodnego z kierunkiem przepływu mocy proponowanym przez autora wykresem wzrostu mocy w układzie przeciwnego do kierunku przepływu mocy. Należy więc opisywać straty i sprawność energetyczną a także pole pracy każdego silnika i układu napędowego jako zależne od wielkości fizycznych niezależnych...
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Expedited Re-Design of Multi-Band Passive Microwave Circuits Using Orthogonal Scaling Directions and Gradient-Based Tuning
PublicationGeometry scaling of microwave circuits is an essential but challenging task. In particular, the employment of a given passive structure in a different application area often requires re-adjustment of the operating frequencies/bands while maintaining top performance. Achieving this necessitates utilization of numerical optimization methods. Nonetheless, if the intended frequencies are distant from the ones at the starting point,...
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Szyby zespolone w systemach fasadowych
PublicationW artykule przedstawiono wybrane kryteria techniczne stosowane do oceny jakościowej izolacyjnych szyb zespolonych. Bazując na własnych doświadczeniach, autor zwrócił uwagę na pojawiające się problemy w trakcie odbiorów technicznych na budowie. Przedstawiono także krótki przegląd literatury z zakresu szkła budowlanego i szyb zespolonych.
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Caffeine detection using CB-PLA electrode after Nd:YAG laser ablation in He atmosphere
Open Research DataThe dataset contains electrochemical studies in form of cyclic voltammetry (CV) and differential pulse voltammetry (DPV) of laser-activated 3D printed CB-PLA electrodes. The ablation of the 3D-printed CB-PLA electrodes was carried out using a pulsed LaserBlast 500 Nd:YAG laser (Quantel, France) operating at 1064 nm and a 6 ns pulse duration.
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Looking for a minimum exergy destruction in hierarchical cycle
PublicationThe paper presents results of energy analysis, complemented with an exergy balance, of hierarchical thermodynamic cycle. Proposed cycle is a binary vapour cycle based on a model of real supercritical steam power plant. Energy analysis is used to preliminary optimization of the cycle and the exergy losses analysis is proposed to perform optimization of heat transfer processes, which are essential for hierarchical cycles. Proposed...
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Comparison of XPS spectra of Ag3d for silver nanostructures and bulk material
Open Research DataAg nanostructures were prepared on borosilicate glass (Corning 1737F) and Si substrates. In both cases, the substrateswere cleaned with acetylacetone and then rinsed in ethanol. Thin Ag films (2 and 6 nm thickness) were deposited using a tabletop dc magnetron sputtering coater (EM SCD 500, Leica) in pure Ar plasma (argon, Air Products 99.999%). The...
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Propulsion and Maneuvering Systems’ Characteristics of the U.S. Flagged Great Lakes Self-Unloading Bulk Carriers
PublicationPaper contains an overview of the propulsion and maneuvering systems’ characteristics of United States flagged Great Lakes self - unloading bulk carriers. A contrast between the importance of the transport task carried by those vessels to their low number and considerable age suggests the need to review and understand their complexity as well as complexity of their operations in order to provide suitable energy- and operational...
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Financial Consequences of the Introduction of the Fit For 55 on the Example of Poland
PublicationIn Europe and in Poland, there is a growing conviction that climate action is a necessity. When creating long-term strategies or making current decisions, companies are increasingly taking into account issues related to sustainable development and reducing CO2 emissions. Following the signing of the Paris Agreement in 2015, countries around the world pledged to reduce greenhouse gas emissions by 2050 so that the average temperature...
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3D Monitoring - Identification of measurement problems at larger movements of the tracked points
PublicationAuthors identified the problems associated with the determination of the controlled points coordinates by use of automated Total Station placed behind transparent barrier. Important thing in the mentioned analysis was a large change of controlled points position and not stable Total Station’s stand (because of stand’s thermal drift). This two elements, combined with measurement made through glass plate determine the need for impact...
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Scrutiny of power grids by penetrating PV energy in wind farms: a case study of the wind corridor of Jhampir, Pakistan
PublicationThis study examines the problems caused by intermittent renewable energy sources, especially wind farms, and suggests a different solar energy penetration strategy to improve their loading capacity. The study uses real-time data from a wind farm in Jhampir, Pakistan, to analyse and assess various aspects of grid stations connected to wind farms. Electrical Transient Analyzer Program is used to validate the results by linking...
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Scrutiny of power grids by penetrating PV energy in wind farms: a case study of the wind corridor of Jhampir, Pakistan
PublicationThis study examines the problems caused by intermittent renewable energy sources, especially wind farms, and suggests a different solar energy penetration strategy to improve their loading capacity. The study uses real-time data from a wind farm in Jhampir, Pakistan, to analyse and assess various aspects of grid stations connected to wind farms. Electrical Transient Analyzer Program is used to validate the results by linking these...
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Simulating Power Generation from Photovoltaics in the Polish Power System Based on Ground Meteorological Measurements—First Tests Based on Transmission System Operator Data
PublicationThe Polish power system is undergoing a slow process of transformation from coal to one that is renewables dominated. Although coal will remain a fundamental fuel in the coming years, the recent upsurge in installed capacity of photovoltaic (PV) systems should draw significant attention. Owning to the fact that the Polish Transmission System Operator recently published the PV hourly generation time series in this article, we aim...
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Synergistic effects of a swirl generator and MXene/ water nanofluids used in a heat exchanger pipe of a negative CO2 emission gas power plant
Publicationfocus on optimizing heat exchangers contributes to improved temperature control mechanisms, ensuring the sustainable operation of innovative power plants working towards negative CO2 emissions. In the realm of oxy-combustion within Negative CO2 Emission Power Plants (nCO2PP), the temperature of combustion products surpasses 3000 (K). Addressing this challenge, the imperative arises to reduce these elevated temperatures to a manageable...
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Problems of varistor quality assessment during exploitation
PublicationVaristors are commonly used elements which protect power supply networks against high-voltage surges or lightning. Therefore, quality and endurance of these elements is important to avoid losses when an expensive laboratory equipment would not be protected from random overvoltages. Additionally, excessive leakage currents generate serious costs due to high energy consumption. The paper presents shortly properties of varistors that...
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The Bridge of Data Project Objectives
PublicationOpen Research Data (ORD) is one of the emerging trends for researchers across the globe. However, it has to be stressed that the level of implementation and awareness of ORD varies between countries. Many initiatives have been created in Polish scientific institutions to support the process of opening publications. These are mainly Open Access (OA) repositories, implementing the so-called green road of OA. However, only a few universities...
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Open extensive IoT research and measurement infrastructure for remote collection and automatic analysis of environmental data.
PublicationInternet of Things devices that send small amounts of data do not need high bit rates as it is the range that is more crucial for them. The use of popular, unlicensed 2.4 GHz and 5 GHz bands is fairly legally enforced (transmission power above power limits cannot be increased). In addition, waves of this length are very diffiult to propagate under field conditions (e.g. in urban areas). The market response to these needs are the...
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Optimal Placement of Phasor Measurement Unit in Power System using Meta-Heuristic Algorithms
PublicationThe phasor measurement units (PMUs) play an important and vital role in power system monitoring and controlling, since they provide the power system phasors stamped with a common real time reference through a global positioning system (GPS). Indeed, from economical point of view it is not possible to set PMUs in all system buses due to the high cost and the requirement of more complex communication...
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Fractionation and origin of dissolved and colloidal organic nitrogen in BNR plant effluent
PublicationThe characteristics of effluent dissolved and colloidal organic nitrogen (DON and CON) as well as their origin, fate and biodegradability in wastewater treatment plants and receiving waters were identified as the major issues that limit the ability to achieve low total N in the effluent. This study presents the results of a comprehensive survey, which was conducted in eight biological nutrient removal (BNR) WWTPs in northern Poland....
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The system for remote monitoring of a vertical axis wind farm
PublicationThe article presents a system for remote monitoring of working parameters of a wind turbine with a vertical axis. The monitoring system was built using a Raspberry PI 3 microcomputer with the Raspbian operating system and a MicroDAQ E2000 measuring card. The developed system enables monitoring the power output of the generator, torque on the turbine shaft, turbine speed and wind speed. The values of the monitored parameters are...
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The shape of an ROC curve in the evaluation of credit scoring models
PublicationThe AUC, i.e. the area under the receiver operating characteristic (ROC) curve, or its scaled version, the Gini coefficient, are the standard measures of the discriminatory power of credit scoring. Using binormal ROC curve models, we show how the shape of the curves affects the economic benefits of using scoring models with the same AUC. Based on the results, we propose that the shape parameter of the fitted ROC curve is reported...
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Energy Yield Generated by a Small Building Integrated Photovoltaic Installation
PublicationIn the recent years photovoltaic (PV) industry has experienced a major growth, caused by the ever present annual decrease in module production prices and the expanding awareness of the general public in terms of renewable energy. There are numerous ways to implement PV modules as an additional energy source for a building, be it mounted on the rooftop, or building integrated (BIPV). An analysis of BIPV consisting of 8 modules with...
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Factors Shaping the Working Environment, Living Conditions and Recreation on Board Ship
PublicationA seagoing ship is a working place, an accommodation space and a recreation area at the same time. Being exposed to harsh physical conditions, it must satisfy different requirements. The human organism and its qualities become a point of reference here; consequently, the functions and spatial arrangement and interiors of a ship must be subordinated to its needs. The organisation of the space in contemporary ships meant for human...
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Exhaled breath gas sensing using pristine and functionalized WO3 nanowire sensors enhanced by UV-light irradiation
PublicationThe development of advanced metal-oxide-semiconductor sensing technologies for the detection of Volatile Organic Compounds (VOCs) present in exhaled breath is of great importance for non-invasive, cheap and fast medical diagnostics. Our experimental studies investigate the effects of operating temperature selection and UV-light irradiation on improving the response of WO3 nanowire sensors towards exhaled breath exposure. Herein,...
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Generalized regression neural network and fitness dependent optimization: Application to energy harvesting of centralized TEG systems
PublicationThe thermoelectric generator (TEG) system has attracted extensive attention because of its applications in centralized solar heat utilization and recoverable heat energy. The operating efficiency of the TEG system is highly affected by operating conditions. In a series-parallel structure, due to diverse temperature differences, the TEG modules show non-linear performance. Due to the non-uniform temperature distribution (NUTD) condition,...
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Imaging of biological samples: crassula arborescens
Open Research DataOne of the tasks of modern botany is to describe the relationship between climatic conditions and other environmental factors and the anatomical structure and adaptation of species present in given geographic areas. The work [1] focuses on anatomical and morphological studies of leaves of plants from the coarse family. Species tested belong to leaf...
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Phosphorus and nitrogen forms in liquid fraction of digestates from agricultural biogas plants
PublicationThe novelty of the presented research is the determination of the nitrogen and phosphorus fraction in the liquid fraction of digestate from agricultural biogas plants. This information is important because it can help in proposing possible further liquid fraction management or developing of new technologies for their purification. The research covered digestates from agricultural biogas plants, obtained from the fermentation of...
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The Influence of External Load on the Performance of Microbial Fuel Cells
PublicationIn this work, the effect of the external load on the current and power generation, as well as on the pollutant removal by microbial fuel cells (MFCs), has been studied by step-wise modifying the external load. The load changes included a direct scan, in which the external resistance was increased from 120 Ω to 3300 Ω, and a subsequent reverse scan, in which the external resistance was decreased back to 120 Ω. The reduction in the...
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SiC-based T-type modules for multi-pulse inverter with coupled inductors
PublicationThe paper presents SiC-based three-level T-type modules designed for a high-performance 30kVA DC/AC inverter operating at high frequency 85 kHz with low THD of the output voltage. This inverter system consists of two integrated parts. The first part is active and contains three parallelconnected three-phase T-type modules built with fast-switching SiC power transistors. The second, passive part of the system is a set of inductors...
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Influence of operating pressure on the durability of a satellite hydraulic motor supplied by rapeseed oil
PublicationThis article describes the results of a durability test of a hydraulic satellite motor supplied by rapeseed oil. The tests were carried out on a test stand in a power recuperation system. The tests of the motor were carried out at a constant shaft speed for three fixed pressure drops in the motor. This made it possible to demonstrate the influence of the motor operating pressure on the durability of the satellite mechanism. The...
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Parametric method for evaluating optimal ship deadweight
PublicationThe paper presents a method of choosing the optimal value of the cargo ships deadweight. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper ship for a given transportation task. The deadweight is determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate (RFR). The...
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Review of Methods for Diagnosing the Degradation Process in Power Units Cooperating with Renewable Energy Sources Using Artificial Intelligence
PublicationThis work is based on a literature review (191). It mainly refers to two diagnostic methods based on artificial intelligence. This review presents new possibilities for using genetic algorithms (GAs) for diagnostic purposes in power plants transitioning to cooperation with renewable energy sources (RESs). The genetic method is rarely used directly in the modeling of thermal-flow analysis. However, this assignment proves that the...
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Optimization of combined heat and power (CHP) market allocation: The case of Poland
PublicationCombined heat and power (CHP), that is production of electricity and useful heat in a single thermodynamic process, is a way of primary energy saving and emission reduction. Therefore, promotion of the electricity from high-efficiency cogeneration (CHP-E) was encouraged in the European Union. However, CHP-E promotion mechanisms proved low effectiveness in certain countries, like Poland, where the prices of certificates of origin...
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Singlet Exciton Diffusion in Vacuum-Evaporated Films of Amine-Based Materials as Studied by Photocurrent and Photoluminescence Quenching Methods
PublicationThe singlet exciton diffusion lengths are determined by the photoconductivity as well as the luminescence surface quenching technique, in vacuum‐evaporated layers of (4,4′,4″‐tris(N‐(3‐methylphenyl)‐N‐phenylylamino) triphenylamine) (m‐MTDATA), 4,4′,4″‐tris[2‐naphthyl(phenyl)amino] triphenylamine (2TNATA), and N,N′‐diphenyl‐N,N′‐bis(3‐methylphenyl)‐[1,1′‐biphenyl]‐4,4′‐diamine (TPD) which are frequently used for fabrication of electroluminescent...
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Performance and Energy Aware Training of a Deep Neural Network in a Multi-GPU Environment with Power Capping
PublicationIn this paper we demonstrate that it is possible to obtain considerable improvement of performance and energy aware metrics for training of deep neural networks using a modern parallel multi-GPU system, by enforcing selected, non-default power caps on the GPUs. We measure the power and energy consumption of the whole node using a professional, certified hardware power meter. For a high performance workstation with 8 GPUs, we were...
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Fault-tolerant performance of the novel five-phase doubly-fed induction generator
PublicationThe article presents the concept of a new design of a multi-phase doubly-fed induction generator (DFIG). The innovative design approach uses a five-phase power supply from the rotor side of the generator with a three-phase classic stator power supply. Modern three-phase doubly-fed induction generators are the dominant choice for Wind Energy Conversion Systems (WECS). Solutions of this type are sensitive to the loss of at least...
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Analysis of diagnostic informativeness of the exhaust temperature of a naval gas turbine
PublicationThe conducted investigations aimed to carry out an analysis of the possibility that the failures identification in the automatic control system of a gas turbine engine could be worked out on the basis of measurements of the exhaust stream temperature behind the gas generator. The exhaust temperature represents a basic control parameter, enabling technical state evaluation of the engine within the operation process, which is observed...
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Diagnostics of zno varistors by means of nondestructive testing
PublicationStandard industrial testing of high-voltage varistors for surge arresters demands application of high voltages and intensive currents. Nondestructive methods for varistor quality and endurance evaluation have been proposed and described. They rely on the application of resonant ultrasound spectroscopy, electro-ultrasonic spectroscopy, noise measurement and nonlinearity testing at voltages lower than continuous operating range....
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Promising Nanoparticle-Based Heat Transfer Fluids—Environmental and Techno-Economic Analysis Compared to Conventional Fluids
PublicationProviding optimal operating conditions is one of the major challenges for effective heating or cooling systems. Moreover, proper adjustment of the heat transfer fluid is also important from the viewpoint of the correct operation, maintenance, and cost efficiency of these systems. Therefore, in this paper, a detailed review of recent work on the subject of conventional and novel heat transfer fluid applications is presented. Particular...