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Search results for: REFERENCE GAS MIXTURES
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Relation of the polymorphism of cyp51A sequence and the susceptibility of Aspergillus fumigatus isolates to triazoles determined by commercial gradient test (Etest) and by reference methods
PublicationThe aim of this study was to evaluate the accuracy of commercial gradient test (Etest) in the detection of triazole resistant Aspergillus fumigatus isolates using reference microdilution methods and the analysis of sequences of the cyp 51A gene. The study was performed on twenty clinical isolates which were identified as Aspergillus fumigatus based on the DNA sequences of the ITS1-2 fragment of ribosomal DNA and the β-tubulin gene,...
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Biocomposites from recycled resources as candidates for laboratory reference material to validate analytical tools used in organic compounds emissions investigation
PublicationA suitably chosen reference material should meet specific criteria like representing one of the compound classes most commonly occurring in indoor materials as well as having optimal long-term stability during storage and transport to its destination point and having a compact size. The described interdisciplinary pilot research was aimed to develop and characterize a polymer-based candidate for the laboratory reference material...
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The effects of gas exposure on the graphene/AlGaN/GaN heterostructure under UV irradiation
PublicationThis work demonstrates a graphene/AlGaN/GaN sensing device with two-dimensional electron gas (2DEG) toward nitrogen dioxide (NO2), tetrahydrofuran, and acetone detection under UV light irradiation. We propose combining measurements of the DC characteristics with a fluctuation-enhanced sensing method to provide insight into the gas detection mechanisms in the synergistic structure of highly stable GaN and gas-sensitive graphene....
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Experimental investigation of domestic gas boiler fitted with ORC module
PublicationIn the paper the prototype of innovative domestic cogenerative ORC system, consisting of a conventional gas boiler and a small size axial vapour microturbines (in-house designed for ORC and the commercially available for Rankine cycle (RC)), evaporator and condenser were scrutinised. In the course of study the fluid working temperatures, rates of heat, electricity generation and efficiency of the whole system were obtained. The...
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Reference LED source of subnanosecond pulses of broadband optical radiation
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A Reference Point Approach to Bi-Objective Dynamic Portfolio Optimization
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Problem of selection of reference plane with deep and wide valleys analysis
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A comparison of Bluetooth scatternet formation algorithms with reference to interference issues
PublicationZe względu na fakt, iż scatternety Bluetooth mogą być tworzone w różnoraki sposób, w artykule podjęto próbę ich porównania pod kątem kilku istotnych parametrów (ze szczególnym uwzględnieniem aspektu potencjalnych interferencji).
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Investigation of matrix-free generation of methyl chloride as a reference material
PublicationW pracy opisano badania nad wykorzystaniem włókien szklanych do otrzymywania bezmatrycowych materiałów odniesienia zawierających chlorek metylu. Chlorek metylu jest uzyskiwany w wyniku termicznego rozkładu związku powierzchniowego. Przedstawiono wyniki badań dla trzech różnych włókien szklanych (o różnej grubości), pokrytych warstwą glinu.
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Green Chemistry Metrics with Special Reference to Green Analytical Chemistry
PublicationThe concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor,...
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OPTIMIZATION OF THE LAST STAGE OF GAS-STEAM TURBINE USING A HYBRID METHOD
PublicationThis paper relates to the CFD calculation of a new turbine type which is in the phase of theoretical analysis, because the working fluid is a mixture of steam and gas generated in wet combustion chamber. At first, this article concentrates on a possibility of streamlining the flow efficiency of a last stage of axial turbine working on gas-steam mixture using a hybrid of the particle swarm optimization algorithm with the Nelder-Mead...
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Thermal failure of a second rotor stage in heavy duty gas turbine
PublicationThe impulse mode of operation and the supply of various types of fuels causes frequent failures even in the heavy duty gas turbines. The paper presents the ravages of second rotor stage failure in a gas turbine. The excessive thermal elongation rise caused by fuel change was indicated as the main cause. We applied nonlinear numerical analysis, preceded by thermodynamic calculations of the turbine and visual inspection of the effects...
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Inlet air fogging of marine gas turbine in power output loss compensation
PublicationThe use of inlet air fogging installation to boost the power for gas turbine engines is widely applied in the power generation sector. The application of fogging to mechanical drive is rarely considered in the literature [1]. This paper will cover some considerations relating to its application to gas turbines in ship drive. There is an important evaporative cooling potential throughout the world when the dynamic data is evaluated,...
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Low and high energy explosive materials used in shale gas recovery
PublicationNowadays the explosives are widely used in many areas of life, including industry and mining. A wide range of explosive materials is used in the petroleum industry - from low to high explosives. Recently, as the unconventional oil and gas production became possible, explosives are also found to be used in perforators during the pre-completion stage of the fracturing process. This paper presents literature on theoretical and practical...
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Wetting of different solid materials with solutions of surfactants mixtures
PublicationBadanie zdolności zwilżających mieszanin niejonowego surfaktantu gemini S-10 z surfaktantami anionowymi CsDS (dodecylosiarczan cezu) i LiDS (dodecylosiarczan litu). Badane powierzchnie różniły się stopniem hydrofobowości (szkło, stal, polimetakrylan metylu). Niektóre mieszaniny wykazywały synergizm w procesie zwilżania.
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Influence of aggregates angularity on the locking point of asphalt mixtures
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Adsorption study of surfactants and biosurfactants mixtures at different interfaces
PublicationZbadano napięcia powierzchniowe i międzyfazowe roztworów mieszaniny surfaktantów niejonowych (Rokanol L7 i Rokanol NL8) i biosurfaktantu (JBR 425) i ich mieszanin. Olejową fazę stanowił dodekan oraz olej bazowy PAO. Wykazano synergizm wartości napięcia międzyfazowego przy CMC jedynie w przypadku mieszaniny Rokanolu L7 i JBR 425 i tylko dla granicy faz olej/woda.
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Flow boiling of oil-refrigerant mixtures in smooth tubes
PublicationPrzedstawiono wyniki badań współczynnika przejmowania ciepła i spadku ciśnienia podczas wrzenia czynników R 22, R 134a i R 407C i ich mieszanin z olejem w rurach gładkich. Opisano procedurę badawczą. Udział masowy oleju w mieszaninie z czynnikiem wynosił 0,1% i 5%. Zaobserwowano negatywny wpływ obecności środka smarnego we wrzącym czynniku chłodniczym.
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Effect of some organic solvent - water mixtures composion on precipitated calcium carbonate in carbonation process
PublicationPrecipitated calcium carbonate particles were obtained during carbonation of calcium hydroxide slurry with carbon dioxide. Aqueous solutions of isopropyl alcohol, n-butanol and glycerol were used as solvents. Concentration of organic additives in the reactive mixture was from 0 to 20 % (vol.). Precipitation process were performed in a stirred tank reactor equipped with gas distributor. Multimodal courses of particles size distribution...
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Intermolecular Interactions of Edaravone in Aqueous Solutions of Ethaline and Glyceline Inferred from Experiments and Quantum Chemistry Computations
PublicationEdaravone, acting as a cerebral protective agent, is administered to treat acute brain infarction. Its poor solubility is addressed here by means of optimizing the composition of the aqueous choline chloride (ChCl)-based eutectic solvents prepared with ethylene glycol (EG) or glycerol (GL) in the three different designed solvents compositions. The slurry method was used for spectroscopic solubility determination in temperatures...
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Domestic ORC micro-CHP combined with a commercial gas boiler
PublicationThe chapter presents the results of experimental studies conducted during the launch of the first in Poland demonstration prototype of the micro ORC coupled to a domestic gas boiler. The accomplished studies indicated the possibility for the ORC module to work with such boiler (autonomous source of heat) with a prototype single-stage axial micro turbine as the expansion machine. Confirmation of that fact has been delineated in...
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Modeling of low calorific gas burning in a deficient oxygen environment and high-temperature oxidizer
PublicationThe experimental research will be performed using the experimental facility with a combustion chamber. The oxygen concentration in combustion oxidizers will be varied from 21% by volume (normal) air to 2%. The test combustion chamber will be fed with propane or methane as the reference fuel, then with low calorific fuels as test gases obtained by mixing various combustible components, e.g. H2, CH4, CO, and neutral gases, e.g. N2,...
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Special Issue on “Advanced Liquid Waste and Gas Waste Treatment Processes”
PublicationThe editorial contains a short review of the content of the Special Issue on waste gas and liquid streams treatment strategies.
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Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
PublicationA weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exotericchemical reaction of A->B type, which takes place in a gas, may be reversible or not. Two types of sound areconsidered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction.For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiencyof...
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Non-Linear Interaction of Harmonic Waves in a Quasi-Isentropic Flow of Magnetic Gas
PublicationThe diversity of wave modes in the magnetic gas gives rise to a wide variety of nonlinear phenomenaassociated with these modes. We focus on the planar fast and slow magnetosound waves in the geometryof a flow where the wave vector forms an arbitrary angleθwith the equilibrium straight magnetic field.Nonlinear distortions of a modulated signal in the magnetic gas are considered and compared to thatin unmagnetised gas. The case of...
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Operational causes of fatigue failures within the passages of gas turbine engines
PublicationThe short profile of a fatigue wear process of gas turbine engine's constructional elements has been introduced in the article. The primary causes of a fatigue cracks formation within the mechanical system as well as within the passages of the engine have been showed. Especial attention was devoted to the low-cycle fatigue, what is associated with unsteady thermal-flow processes being worked out in the passages.The selected damages...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublicationIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Occurrence and Determination of Volatile Fatty Acids in Landfill Leachate and Gas
PublicationIn landfills containing biological matter volatile fatty acids (VFAs) are generated at high rate at the early stage of waste disposal and their content in leachate is high as compared to the leachate from old parts of landfill since they are converted to methane gas. Monitoring of the leachate for the content of VFAs can help determine the processes occurring in waste and possible effect of the leachate on the environment in the...
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Phytochemical screening and biological evaluation of Greek sage (Salvia fruticosa Mill.) extracts
PublicationThis study explores the influence of extraction solvents on the composition and bioactivity of Salvia fruticosa extracts. Ultrasound-assisted extraction with water, ethanol and their mixtures in variable proportions was used to produce four different extracts. An untargeted UPLC/MS‑based metabolomics was performed to discover metabolites profile variation between the extracts. In the analyzed samples, 2704 features had been detected,...
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The Synergistic Microbiological Effects of Industrial Produced Packaging Polyethylene Films Incorporated with Zinc Nanoparticles
PublicationZinc compounds in polyolefin films regulate the transmission of UV-VIS radiation, affect mechanical properties and antimicrobial activity. According to hypothesis, the use of zinc- containing masterbatches in polyethylene films (PE) with different chemical nature—hydrophilic zinc oxide (ZO) and hydrophobic zinc stearate (ZS)—can cause a synergistic effect, especially due to their antimicrobial properties. PE films obtained on an...
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The bile salt content of human bile impacts on simulated intestinal proteolysis of β-lactoglobulin
PublicationThe gastrointestinal hydrolysis of food proteins has been portrayed in scientific literature to predominantly depend on the activity and specificity of proteolytic enzymes. Human bile has not been considered to facilitate proteolysis in the small intestine, but rather to assist in intestinal lipolysis. However, human bile can potentially influence proteins that are largely resistant to gastric digestion, and which are mainly hydrolysed...
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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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Reactivity study of a β-diketiminate titanium(III) complex with a phosphanylphosphido ligand towards chlorophosphanes. A new method of synthesis of β-diketiminate titanium(IV) complexes with versatile phosphanylphosphinidenes
PublicationThe reactivity of ab-diketiminate titanium(III) complex with a phosphanylphosphido ligand, [MeNacNacTi(Cl){g2-P(SiMe3)-PtBu2}] (1)(MeNacNac= [Ar]NC(Me)CHC(Me)N[Ar]; Ar = 2,6-iPr2Ph), was investigatedtowards selected chlorophosphanes, such astBu2PCl,iPr2PCl, Cy2PCl, (Cy)tBuPCl, (Me)tBuPCl, (Ph)tBuPCl, Ph2PCl, (iPr2N)tBuPCl and (Et2N)2PCl. The reactions withtBu2PCl and Ph2PCl lead mainly to theearlier described complex [MeNacNacTi(Cl){g2-P-PtBu2}]...
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Glass-ceramic sealants and steel interconnects: accelerated interfacial stability and reactivity tests at high temperature
PublicationHigh-temperature reactions between glass-ceramic sealants and Fe-Cr alloy interconnects may lead to the formation of undesirable phases, and consequently degradation of solid oxide fuel/electrolyser devices. In this work, three different glass-ceramic sealants (Na-containing, Ba-containing, Sr-containing compositions) and Fe22Cr stainless steel powders (raw and pre-oxidised) are considered in order to test their chemical reactivity...
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Performance tuning of chitosan-based membranes by protonated 2-Pyrrolidone-5-carboxylic acid-sulfolane DES for effective water/ethanol separation by pervaporation
PublicationToday, the applicability of deep eutectic solvents (DES) in various fields, including membrane science and technology, is extensively investigated. In pioneering works, we have implemented different DES as a component of chitosan (CS)-based flat membranes for pervaporation (PV) separation. Herein, we present a new protonated (by sulphuric acid) 2-Pyrrolidone-5-carboxylic acid: sulfolane DES, as a green additive for its chemical...
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Two-Dimensional Gas Chromatography Coupled With Mass Spectrometry in Food Analysis
PublicationThe development of instrumental analytical techniques provided the opportunity for in-depth characterization of many food matrices. In particular, the use of gas chromatography coupled with mass spectrometry gives impressive results in terms of quality and authenticity testing, conducting food freshness evaluations and contamination assessments. A new variant of gas chromatography, namely two-dimensional gas chromatography (GC...
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Radioisotope measurements of the liquid-gas flow in the horizontal pipeline using phase method
PublicationThe paper presents application of the gamma-absorption method to a two-phase liquid-gas flow investigation in a horizontal pipeline. The water-air mixture was examined by a set of two Am-241 radioactive sources and two NaI(Tl) scintillation probes. For analysis of the electrical signals obtained from detectors the cross-spectral density function (CSDF) was applied. Results of the gas phase average velocity measurements for CSDF...
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Degradation of protective coatings in steel chimneys of flue gas desulfurisation system
PublicationThis paper presents problems associated with corrosion of steel stacks and changes in philosophy of corrosion protection when implemented into flue gas desulphurization systems. In-situ tests were taken by means of electrochemical impedance spectroscopy at the stack which discharges flue gas before wet lime/limestone desulphurization. A very quick electrolyte absorption by the spherical infill vinylester coating was found using...
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Negative carbon dioxide gas power plant integrated with gasification of sewage sludge
PublicationOne of the primary objectives of the negative carbon dioxide gas power plant (nCO2PP) is to develop an innovative technology confirming the possibility of the use of sewage sludge to produce electricity while having a positive impact on the environment. In this paper, a mathematical model is presented to estimate thermodynamic parameters of the system in relation to the gasification process and changes in such parameters in the...
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Dissociative ionization dynamics of dielectric gas C3F7CN
PublicationFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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CLAY MINERALS – MINERALOGY AND PHENOMENON OF CLAY SWELLING IN OIL & GAS INDUSTRY
PublicationAmong the minerals found in the earth's crust, clay minerals are of the widest interest. Due to the specific properties such as plasticity, absorbing and catalytic properties clay minerals are used in many industries (oil & gas, chemistry, pharmacy, refractory technology, ceramics etc.). In drilling, a phenomenon of swelling clays is frequently observed. It has an important impact on the cementing quality. During the last few decades...
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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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Nitrogen dioxide gas-sensing detection with GO modified CuO thin films
PublicationGas sensors have been continuously developed over the last few decades for several applications including air quality monitoring, automotive industry and recently for medical use. Gas sensors are usually based on metal oxides (MOXs), such as SnO2, TiO2, ZnO, WO3, CuO. Recently, new materials such as graphene oxide and heterostructures of graphene oxide and metal oxides are utilized for gassensing applications.
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Mobile Gas Chromatographs Coupled with Mass and Ion Mobility Spectrometers and their Applications
PublicationThe articles describes the developments un combining of mass and ion mobility spectrometers (MS, IMS0 with miniature gas chromatographs (GC). The examples of applications of miniaturised GC-MS and GC-IMS devices are presented.
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Enhanced visible light-activated gas sensing properties of nanoporous copper oxide thin films
PublicationMetal oxide gas sensors are popular chemoresistive sensors. They are used for numerous tasks, including environmental and safety monitoring. Some gas-sensing materials exhibit photo-induced properties that can be utilized for enhanced gas detection by modifying the sensor selectivity and sensitivity when illuminated by light. Here, we present the gas sensing characteristics of highly nanoporous Cu2O thin films towards both electrophilic...
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Effects of UV light irradiation on fluctuation enhanced gas sensing by carbon nanotube networks
PublicationThe exceptionally large active surface-to-volume ratio of carbon nanotubes makes it an appealing candidate for gas sensing applications. Here, we studied the DC and low-frequency noise characteristics of a randomly oriented network of carbon nanotubes under NO2 gas atmosphere at two different wavelengths of the UV light-emitting diodes. The UV irradiation allowed to sense lower concentrations of NO2 (at least 1 ppm) compared to...
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Chemiresistive gas sensors based on carbon nanotubes - fabrication and application
PublicationMany types of sensors have been invented to identify and quantify chemical contamination in the gas phase. Sensors based on carbon nanotubes are particularly attractive because of their wide range of applicaions and potential use in electronic nose that can be controlled using algorithms of Artificial Intelligence. Sensor functions, fabrication and selected applications are reviewed and discussed with focus on chemiresistors. Drawbacks...
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Electrical responses of nanoporous NiO films for light-activated nitrogen dioxide and acetone gas sensing
Open Research DataThe chemoresistive sensor response of nanoporous NiO films prepared by advanced gas deposition was investigated with and without simultaneous light irradiation, to detect nitrogen dioxide and acetone gases. The presented data show electrical responses presented as sensor resistance or relative changes in sensor resistance under selected environment...
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Identification of defected sensors in an array of amperometric gas sensors
PublicationPurpose Amperometric gas sensors are commonly used in air quality monitoring in long-term measurements. Baseline shift of sensor responses and power failure may occur over time, which is an obstacle for reliable operation of the entire system. The purpose of this study is to check the possibility of using PCA method to detect defected samples, identify faulty sensor and correct the responses of the sensor identified as faulty. Design/methodology/approach In...
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OPERATION OF TWO-SHAFT GAS TURBINE IN THE RANGE OF OPEN ANTI-SURGE VALVE
PublicationThis paper presents experimental tests of full-scale two-shaft gas turbine in the range of open anti-surge valve (ASV). The tests were carried out in a laboratory gas- turbine test stand belonging to Department of Automation and Power Engineering , Faculty of Ocean Engineering and Ship Technology , Gdańsk University of Technology. The tests covered the start-up and low load operation of the turbine set in the range of open...