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Search results for: ANECHOIC CHAMBER
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Adaptive Wavelet-Based Correction of Non-Anechoic Antenna Measurements
PublicationNon-anechoic measurements represent an affordable alternative to evaluation of antenna performance in expensive, dedicated facilities. Due to interferences and noise from external sources of EM radiation, far-field results obtained in non-ideal conditions require additional post-processing. Conventional correction algorithms rely on manual tuning of parameters, which make them unsuitable for reliable testing of prototypes. In this...
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Rotordynamic characteristics of a chamber seal
PublicationThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal of a modernized type. The experiments were performed on a single-stage air model turbine of the impulse type. The experiments were performed on a single-stage air model turbine of the impulse type. The experimental data were compared with theoretical results obtained by means of CFD Fluent Code....
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Multi-Taper-Based Automatic Correction of Non-Anechoic Antenna Measurements
PublicationPrototype measurements belong to the key steps in the development of antenna structures. Although accurate validation of their far-field performance can be realized in dedicated facilities, such as anechoic chambers, the high cost of their construction and maintenance might not be justified if the main goal of measurements is to support teaching or low-budget research. Instead, they can be performed in non-anechoic conditions and...
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Influence of boundary conditions in calibration chamber
PublicationPrzedstawiono wyniki badań modelowych penetracji w komorze kalibracyjnej z zastosowaniem modeli o różnej średnicy. Badania przeprowadzono w piasku średnio zagęszczonym i zagęszczonym przy stałej składowej poziomej naprężenia i przy składowej pionowej naprężenia w gruncie do 400 kPa. Określono wpływ warunków brzegowych na uzyskane wyniki oporu podstawy/oporu stożka lub ostrza dylatometru. Wyznaczono współczynniki korekcyjne oraz...
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Impedance spectroscopy of single chamber SOFC.
PublicationMechanizm działania jednokomorowego ogniwa paliwowego SOFC, które pracuje w mieszaninie powietrza i paliwa, nie jest do końca zbadany. W tej pracy przedstawiono wyniki badań ogniwa paliwowego zbudowanego z tlenku cyrkonu stabilizowanego itrem jako nośnego elektrolitu, cermetu z tlenku niklu jako anody i perovskitu LSCF jako katody w temperaturach 500-700C z użyciem mieszaniny propanu i powietrza. Wykorzystując spektroskopię impedancyjną...
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Automatic Correction of Non-Anechoic Antenna Measurements using Low-Pass Filters
PublicationPrototype measurements belong to key steps in the development of antenna structures. They are normally performed in expensive facilities, such as anechoic chambers (ACs). Alternatively, antenna performance can be extracted (at a low cost) in non-anechoic conditions upon appropriate post-processing. Unfortunately, existing correction algorithms are difficult to set up and prone to failure, which limits their practical usefulness....
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Rational method of grit chamber efficiency determination
PublicationAlthough grot chambers are designed with utmost care, they still remain difficuly to control. As concentration of grit is non-uniform, representative measurements of the sand concentration is a very complex issue. In the paper the results of measure,ents performed at WTP in Gdańsk and Gdynia were analyzed. The proposed method to determine grit chambers efficiency is based on comparison of suspension flow in the inlet and flux of...
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Numerical modelling of DMT test in calibration chamber
PublicationAnaliza numeryczna badania DMT wykonanego w komorze kalibracyjnej w Katedrze Geotechniki Politechniki Gdańskiej. Badania przeprowadzono w piasku Lubiatowo średnio zagęszczonym i zagęszczonym przy składowej pionowej naprężenia 100 kPa. Modelowano proces wciskania ostrza dylatometru oraz fazę odkształcenia membrany. Analiza parametryczna uwzględnia wpływ wartości kąta tarcia wewnętrznego i dylatancji oraz modułu odkształcenia uzyskanych...
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Use of calibration chamber as a large triaxial apparatus
PublicationModelowanie wycinka kolumny żwirowej o wysokości 1 m w komorze kalibracyjnej. Badania przeprowadzono przy różnym naprężeniu bocznym w komorze. Kolumnę poddano obciążeniu pionowemu przy odkształceniu pionowym do 2%. Określono jej parametry wytrzymałościowe oraz moduły odkształcenia przy obciążeniu oraz w cyklach odciążenie-powtórne obciążenie.
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Reverberation chamber in emc tests of naval systems
PublicationPaper covers the techniques of emission and immunity testing to the electromagnetic field in reverberation chamber. The procedure of he chamber calibration and field homogeneity assessment were covered. The naval forces' product as selected as an example for discussing the testing procedure in the chamber. The paper's summary gives the assortment of methodology in radiation emission testing and immunity to the electromagnetic field...
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Single chamber electrolyte supported SOFC module.
PublicationZaproponowano konstrukcję modułu składającego się z dwóch jednokomorowych ogniw paliwowych SOFC na nośnym elektrolicie. Moduł zbudowany jest z jednego substratu z tlenku ceru i domieszkowanym samarem oraz dwóch anod z cermetu na bazie tlenku niklu i dwóch katod z perovskitu LSCF. Przygotowano i zbadano moduły z różną powierzchnią elektrod, które były testowane w mieszaninach powietrza i propanu. Wielkość elektrod miała silny wpływ...
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Role of composite cathodes in single chamber SOFC.
PublicationZbadano wpływ składu katody na napięcie oraz wydajność ogniw paliwowych pracujących w konfiguracji jednokomorowej. W związku z tym, że takie ogniwo pracuje w mieszanienie powietrza i paliwa, napięcie jest określone przez różnice aktywności katalitycznej anody i katody. Typowy cermet na bazie niklu oraz związki perovskitów pracują dobrze odpowiednio jako anoda i katoda. Jednakże perowskity mają również właściwości katalityczne,...
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Performance of a Porous Electrolyte in Single-Chamber SOFCs
PublicationW pracy przedstawiono wyniki badań ogniwa paliwowego SOFC zbudowanego na bazie domieszkowanego tlenku cyrkonu, cermetu niklowego oraz perovskitu. Elektrolit został przygotowany jako warstwa porowata o grubości 18um. Ogniwo było badane w konfiguracji jednokomorowej.
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COMPUTER ANALYSIS OF HYDRAULIC CONDITIONS IN A SANITARY CHAMBER
PublicationThis paper presents analysis of hydraulic conditions of sewage flow down the slipway (ramp) in the collecting sanitary chamber connecting 3 collectors on the inlet: ⌀600, ⌀800 and ⌀1400 and one on the outlet ⌀1600 mm, with a maximum difference of elevation 5 m. The mathematical model has been made and hydraulic calculations were carried out in steady flow conditions. Then wastewater surface elevation, energy grade line elevation,...
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Multitaper-Based Post-processing of Compact Antenna Responses Obtained in Non-anechoic Conditions
PublicationThe process of developing antenna structures typically involves prototype measurements. While accurate validation of far-field performance can be performed in dedicated facilities like anechoic chambers, high cost of construction and maintenance might not justify their use for teaching, or low-budget research scenarios. Non-anechoic experiments provide a cost-effective alternative, however the performance metrics obtained in such...
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Accurate Post-processing of Spatially-Separated Antenna Measurements Realized in Non-Anechoic Environments
PublicationAntenna far-field performance is normally evaluated in expensive laboratories that maintain strict control over the propagation environment. Alternatively, the responses can be measured in non-anechoic conditions and then refined to extract the information on the structure field-related behavior. Here, a framework for correction of antenna measurements performed in non-anechoic test site has been proposed. The method involves automatic...
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A Low-Cost System for Far-Field Non-Anechoic Measurements of Antenna Performance Figures
PublicationPrototype measurements are the key step in the development of antenna structures. Typically, their far-field characteristics are validated in expensive, dedicated facilities such as open range sites, or anechoic chambers. Despite being necessary for obtaining high-precision data (e.g., for device qualification), the use of costly infrastructure might not be fully justified when the main goal of measurements includes demonstration...
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Penetration resistance of Lubiatowo sand in calibration chamber tests
PublicationAnaliza oporu na wciskanie na stożku sondy statycznej wciskanej na podstawie badań modelowych w komorze kalibracyjnej z kontrolą naprężeń bocznych. Przeprowadzono badania z zastosowaniem standardowej końcówki CPT, dylatometru DMT, mini-stożka CPT oraz pali modelowych o różnej średnicy. Badania wykonano na piasku modelowym z plaży w Lubiatowie w stanie średnio zagęszczonym i zagęszczonym w szerokim zakresie składowej pionowej naprężenia....
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Filter-Hilbert Method for Automatic Correction of Non-Anechoic Antenna Measurements with Embedded Self-Calibration Mechanism
PublicationOne of the most important steps in the process of antenna development involves measurements of its prototype. Far-field performance of radiators is normally characterized in strictly controlled environments such as anechoic chambers which can ensure certification-grade accuracy. Unfortunately, they are also characterized by high construction costs which might not be justified for low-budget research and/or teaching-related activities....
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Low-Cost Open-Hardware System for Measurements of Antenna Far-Field Characteristics in Non-Anechoic Environments
PublicationExperimental validation belongs to the most important steps in the development of antenna structures. Measurements are normally performed in expensive, dedicated facilities such as anechoic chambers, or open-test sites. A high cost of their construction might not be justified when the main goal of antenna verification boils down to demonstration of the measurement procedure, or rough validation of the simulation models used for...
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Four-stroke engine with central located, dyvided combustion chamber
PublicationW artykule przedstawiono oryginalne rozwiązanie konstrukcyjne nowoczesnego czterosuwowego silnika spalinowego z centralnie umieszczoną, dzieloną komorą spalania. Rozwiązanie takie umożliwia znacznie lepsze wykorzystanie ciepła, co oznacza wyższą sprawność i mniejsze zużycie paliwa oraz niższą emisję szkodliwych gazów takich, jak tlenki azotu (NO2), węglowodory (HC) i dwutlenek węgla (CO2). Silnik może pracować na paliwo płynne...
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Comparison of anode and electrolyte support configuration of single- chamber SOFC.
PublicationW pracy przedstawiono wyniki badań jednokomorowych ogniw paliwowych SOFC, wytworzonych na podłożu z anody i elektrolitu. Użyto typowych materiałów wykorzystywanych do budowy dwukomorowych ogniw paliwowych SOFC: elektrolit - domieszkowany tlenek cyrkonu, anoda - cermet niklowo cyrkonowy, katoda - lantanian strontowo manganowy. Ogniwa były przygotowane w technologii odlewania ceramicznego i sitodruku. Parametry syntezy katody były...
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Single chamber solid oxide fuel cell - investigation of cathodes
PublicationSporo uwagi w ostatnim okresie przykuwają jednokomorowe ogniwa w związku z potencjalnym uroszczeniem konstrukcji w porównaniu z konwencjonalnymi ogniwami. W pracy zbadano wpływ warunków syntezy różnych materiałów katodowych na wydajność ogniw. Ogniwa zbudowane zostały z typowych materiałow stosowanych na ogniwa: stabilizowanego tleneku cyrkonu jako elektrolit, cermetu niklowego jako anody oraz samaru kobaltanu domieszkowanego strontem,...
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Porous structures in aspects of transpirating cooling of oxycombustion chamber walls
PublicationA wet oxycombustion chamber, which must be effectively cooled due to high temperature evolved during the oxy-combustion process, by using the phenomena of Reynolds thermal transpiration and Navier slip velocity. Closures needed to execute mass flow rate in a microchannel, which should be treated as a single porous structure in the walls of the combustion chamber, have been obtained by applying a local 3D approach. The Navier-Stokes...
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Architecture Design of a Networked Music Performance Platform for a Chamber Choir
PublicationThis paper describes an architecture design process for Networked Music Performance (NMP) platform for medium-sized conducted music ensembles, based on remote rehearsals of Academic Choir of Gdańsk University of Technology. The issues of real-time remote communication, in-person music performance, and NMP are described. Three iterative steps defining and extending the architecture of the NMP platform with additional features to...
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Mechanical characterization of a gravel column in a calibration chamber operating as a triaxial cell
PublicationA series of tests considering the behavior of gravel columns was performed. A segment of column with a height of 1 m and a diameter of 0.53 m was modelled in a calibration chamber used as a triaxial cell at three different lateral stress applied. The vertical load transferred on the column head was simulated with steady increase of water pressures in the upper and lower membranes. During the loading the volumetric changes in the...
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Performance of the CMS drift-tube chamber local trigger with cosmic rays
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Time-Gating method with automatic calibration for accurate measurements of electrically small antenna radiation patterns in Non-Anechoic environments
PublicationNon-anechoic sites represent a cheap alternative to measurements of antennas in dedicated facilities. However, due to a high noise—from the external EM signal sources and multipath interferences—the quality of radiation patterns obtained in non-anechoic conditions is poor. The characteristics can be corrected using a time-gating method (TGM), which involves filtering of the noise based on temporal analysis of the measured signals....
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Aerated grit chambers hydraulic design equation.
PublicationW pracy zaproponowano metodę wymiarowania piaskowników napowietrzanych. Jej głównymi elementami są wyznaczanie niezbędnej intensywności aeracji ścieków, pola ich prędkości oraz trajektorii cząstek zawiesiny.
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Bead-on-plate welding on S235JR steel by underwater local dry chamber process
PublicationThe article presents the results of the effect of parameters of underwater local dry chamber welding on the properties of padding welds. The effect of heat input and the type of shielding gas on the structure and hardness of welds was established. the functions for estimating the maximum hardness of the heat affected zone have been also elaborated.
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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublicationThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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Numerical modeling of the combustion in a lab-scale pulverized-coal fired combustion chamber
PublicationThis work presents results of numerical modeling of the combustion process inside a lab-scale drop-tube chamber, designed to investigate the slagging properties of the flue ashes, created through the solid fuel firing. Interaction between turbulence and chemistry is accounted by use of probability density function (PDF). FLUENT inputs for non-premixed combustion chemistry modeling are defined. A discrete second phase of the coal...
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Time Projection Chamber (TPC) detectors for nuclear astrophysics studies with gamma beams
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Miniaturized passive emission test chamber for in-situ measurement of emissions of organic compounds
PublicationThe results of many different studies have demonstrated unequivocally that the quality of indoor air is often much worse than that of atmospheric air (outdoor). One of the main groups of chemical compounds present in indoor air, with proven harmfulness to health,are volatile organic compounds (VOCs). VOCs present indoor comprise a wide variety of hydrocarbons and hydrocarbons derivatives including aliphatic, aromatics, alkylbenzens,...
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Single chamber solid oxide fuel cell - current stage of development and prospects
PublicationOgniwa paliwowe należą do jednego z najbardziej wydatnych żródeł energii. W konwencjonalnych ogniwach paliwo i powietrze są dostarczane do ogniwa oddzielnie. Jednokomorowych ogniwo dziala zasilane mieszanina paliwa i powietrza. W pracy przedstawiono obecny stan i perspektywy dlaszego rozwoju jednokomorowych tlenkowych ogniw paliwowych.
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Gas Turbine Cycle with External Combustion Chamber for Prosumer and Distributed Energy Systems
PublicationThe use of various biofuels, usually of relatively small Lower Heating Value (LHV), affects the gas turbine efficiency. The present paper shows that applying the proposed air by-pass system of the combustor at the turbine exit causes tan increase of efficiency of the turbine cycle increased by a few points. This solution appears very promising also in combined gas/steam turbine power plants. The comparison of a turbine set operating...
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Performance of the CMS cathode strip chambers with cosmic rays
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Performance of the CMS drift tube chambers with cosmic rays
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Anode supported single chamber solid oxide fuel cell in CH4-Air Mixture.
PublicationW tej pracy przedstawiono wyniki prac ogniw paliwowych na bazie elektrolitu z tlenku cyrkonu stabilizowanego itrem o grubości 1-2um wytworzonego na podłożu cermetu z tlenku niklu i tlenku cyrkonu stabilizowanego itrem. LSCF był wykorzystany jako katoda. Ogniwo paliwowe było testowane w konfiguracji jednokomorowej w mieszaninie powietrza i metanu. Uzyskano napięcie o wartości 0.8V, zaś moc wynosiła 0.12W/cm2. Zbdadano wpływ przepływu...
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Effect of cathode materials on the performance of single chamber solid oxide fuel cell and module
PublicationW pracy przedstawiono wyniki badań nad jednokomorowym ogniwem paliwowym. Badane były ogniwa przygotowane z różnymi rodzajami materiałow katodowych oraz określana była wydajność ogniwa. Zbudowano i zbadano moduł ogniwa paliwowego jednokomorowego.
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Investigation of the Efficiency of a Dual-Fuel Gas Turbine Combustion Chamber with a Plasma‒Chemical Element
PublicationThe study is devoted to the possibility of increasing the efficiency of the working process in dual-fuel combustion chambers of gas turbine engines for FPSO vessels. For the first time, it is proposed to use the advantages of plasma‒chemical intensification of the combustion of hydrocarbon fuels in the dual-fuel combustion chambers, which can simultaneously operate on gaseous and liquid fuels. A design scheme of a combustion chamber...
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Tire camber angle influence on tire-pavement noise
PublicationTaking into account tire-pavement noise and tires classification with respect to noise emission special measurement methods are usually used. When two of them are applied (the Laboratory Drum Method (DR) and the Close-Proximity Method (CPX)) the investigator has to be sure that the position of the tire is correct. The authors of this paper thought about tire position as tire (wheel) alignment in particular tire camber angle. They...
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Introductory Chapter: Demographic Analysis
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12 [Chapter]. Bound entanglement
PublicationKwantowe splątanie jest jednym z podstawowych elementów kwantowej teorii informacji. Jak wiadomo niskowymiarowe (2otimes 2 i 2otimes 3) splątane stany kwantowe są zawsze destylowalne. W wyższych wymiarach jednak istnieją stany, które mimo, że są splątane nie pozwalają na destylację. Ten rodzaj splątania, nazywany związanym, jest często trudny do wykrycia i pozornie bezużyteczny. Jak pokazują jednak liczne badania splątanie związane...
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Wdrożenia komercyjne chatter-botów
PublicationCelem artykułu jest ocena przydatności wdrożenia systemów chatter-bot, czyli tzw. wirtualnych konsultantów - systemów informatycznych, które potrafią odpowiadać na pytania zadawane w języku naturalnym. Przedstawiono główne czynniki wpływające na funkcjonalność systemu, analizę kosztów wdrożenia i efektywności inwestycji oraz przykłady komercyjnych zastosowań.
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INVESTIGATION OF THE CHARACTERISTICS OF A LOWEMISSION GAS TURBINE COMBUSTION CHAMBER OPERATING ON A MIXTURE OF NATURAL GAS AND HYDROGEN
PublicationT his article is devoted to the investigation of the characteristics of a low-emission gas turbine combustion chamber, which can be used in Floating Production, Storage and Offloading (FPSO) vessels and operates on a mixture of natural gas and hydrogen. A new approach is proposed for modelling the processes of burning out a mixture of natural gas with hydrogen under preliminary mixing conditions in gaseous fuel with an oxidizer...
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Chapter 8 – Active Sampling of Air
PublicationThis chapter reviews the literature information on analytical techniques and laboratory equipment used for active sampling of air (atmospheric and indoor) in regular monitoring research. It describes popular analytical devices applied for sample collection using various types of polymeric bags, e.g. Tedlar bags, Teflon or Nafion bags, and/or stainless steel vacuum containers. It reviews literature data about the application of...
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Introductory Chapter: Evolution of Sample Preparation
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