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Wyszukujesz frazę "spectroscopy" wg kryterium: Temat


Tytuł:
Ultrasonic spectroscopy of silicon single crystal
Autorzy:
Sedlak, P.
Tofel, P.
Sedlakova, V.
Majzner, J.
Sikula, J.
Hasse, L.
Powiązania:
https://bibliotekanauki.pl/articles/220554.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
non-destructive testing
silicon single crystal
electro-ultrasonic spectroscopy
resonant ultrasonic spectroscopy
Opis:
Specimens of Si single crystals with different crystal orientation [100] and [110] were studied by Electro-Ultrasonic Spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: an electric AC signal and an ultrasonic signal, which are working on different frequencies. The ultrasonic wave affects the charge carriers' transport in the structures and the intermodulation electrical signal which is created due to the interaction between the ultrasonic wave and charge carriers, is proportional to the density of structural defects. RUS enables to measure natural frequencies of free elastic vibrations of a simply shaped specimen by scanning a selected frequency range including the appropriate resonances of the measured specimens.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 621-630
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of optical noise in near-infrared range laser hygrometry
Autorzy:
Stacewicz, Tadeusz
Winkowski, Mateusz
Kuk, Natalia
Powiązania:
https://bibliotekanauki.pl/articles/2204345.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hygrometer
laser
absorption spectroscopy
optical interference
Opis:
A contactless laser hygrometer based on light absorption by H2O molecules at 1392.5 nm is described. However, measurement results can be affected by optical noise when applied to an atmospheric tunnel or glass cuvette. The noises (occurring in the form of periodic fringes in the recorded spectrum) come from unexpected interference of the light beams reflected from surfaces of the windows or other optical elements. The method of their suppression is described in this article. It is based on wavelength modulation and signal averaging over the fringes period. Also, an experiment confirming the usefulness of this method is described here.
Źródło:
Metrology and Measurement Systems; 2023, 30, 1; 169--181
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of ethane, methane, formaldehyde and water vapor in the 3.33 μm range
Autorzy:
Winkowski, Mateusz
Stacewicz, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/2106414.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
infrared spectroscopy
multipass
biomarkers
trace gas sensing
Opis:
We describe construction and investigation results of optical trace gas sensor working in the 3.334-3.337 μm spectral range. Laser spectroscopy was performed with a multipass cell. A setup was elaborated for detection of ethane at the 3.3368035 μm absorption line. Analysis of the gas spectra and the experiment have shown that, beside C2H6, the sensor is suitable for simultaneous detection of methane, formaldehyde and water vapor. Due to nonlinearity of the laser power characteristic we decided to detect the fourth harmonic of signal. Additional laser wavelength modulation was applied for optical interference suppression. In result, the precision of ethane detection of approximately 80 ppt has been achieved for the averaging time of 20 seconds. Long-term stability as well as the measurement linearity have also been positively tested. The system is suitable for detecting potential biomarkers directly in human breath.
Źródło:
Metrology and Measurement Systems; 2022, 29, 2; 271--282
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A family of new generation miniaturized impedance analyzers for technical object diagnostics
Autorzy:
Hoja, J.
Lentka, G.
Powiązania:
https://bibliotekanauki.pl/articles/220894.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
technical object diagnostics
impedance spectroscopy
impedance analyzer
Opis:
The paper presents the family of three analyzers allowing to measure impedance in the range of 10 Ω<|Zx|<10 GΩ in a wide frequency range from 10 mHz up to 100 kHz. The most important features of the analyzer family are: miniaturization, low power consumption, low production cost, telemetric controlling and the use of an impedance measurement method based on digital signal processing (DSP). The miniaturization and other above-mentioned features of the analyzers were obtained thanks to the use of the newest generation of large-scale integration chips: e.g. "system on a chip" microsystems (AD5933), 32-bit AVR32-family microcontrollers and specialized modules for wireless communication using the ZigBee standard. When comparing metrological parameters, the developed instrumentation can equal portable analyzers offered by top worldwide manufacturers (Gamry, Ivium) but outperforms them on smaller dimensions, weight, a few times lower price and the possibility to work in a distributed telemetric network. All analyzer versions are able to be put into medium-volume production.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 43-52
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impedance Sensors Made in PCB and LTCC Technologies for Monitoring Growth and Degradation of Pseudomonal Biofilm
Autorzy:
Chabowski, K.
Junka, A. F.
Piasecki, T.
Nowak, D.
Nitsch, K.
Smutnicka, D.
Bartoszewicz, M.
Moczała, M.
Szymczyk, P.
Powiązania:
https://bibliotekanauki.pl/articles/221326.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Pseudomonas aeruginosa
biofilm
interdigitated sensor
impedance spectroscopy
Opis:
The suitability of low-cost impedance sensors for microbiological purposes and biofilm growth monitoring was evaluated. The sensors with interdigitated electrodes were fabricated in PCB and LTCC technologies. The electrodes were golden (LTCC) or gold-plated (PCB) to provide surface stability. The sensors were used for monitoring growth and degradation of the reference ATCC 15442 Pseudomonas aeruginosa strain biofilm in invitro setting. During the experiment, the impedance spectra of the sensors were measured and analysed using electrical equivalent circuit (EEC) modelling. Additionally, the process of adhesion and growth of bacteria on a sensor’s surface was assessed by means of the optical and SEM microscopy. EEC and SEM microscopic analysis revealed that the gold layer on copper electrodes was not tight, making the PCB sensors susceptible to corrosion while the LTCC sensors had good surface stability. It turned out that the LTCC sensors are suitable for monitoring pseudomonal biofilm and the PCB sensors are good detectors of ongoing stages of biofilm formation.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 369-380
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ageing of cadmium telluride radiation detectors and its diagnostics with low frequency noise
Autorzy:
Andreev, A.
Sik, O.
Grmela, L.
Sikula, J.
Powiązania:
https://bibliotekanauki.pl/articles/221866.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
noise spectroscopy
CdTe radiation detectors
ageing process
Opis:
Samples of CdTe single crystals which are used as radiation detectors were periodically measured during a long time interval with different values of an applied voltage. The samples were also periodically exposed during long time periods to high temperatures of 390 K and to rapid changes of temperature from 300 K to 390 K. After 1.5 years of measurements we observed ageing of the samples which resulted in deterioration of their transport characteristics. The resistance of the samples increased significantly and current-voltage characteristics were unstable in time. Noise spectroscopy showed that low frequency noise can be used for detection of CdTe sample ageing as its spectral density increases significantly comparing to the 1/f noise of a high quality sample.
Źródło:
Metrology and Measurement Systems; 2013, 20, 3; 385-394
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving the accuracy of the NDIR-based CO2 sensor for breath analysis
Autorzy:
Prokopiuk, Artur
Bielecki, Zbigniew
Wojtas, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/2052156.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
NDIR
CO2 sensors
breath analysis
absorption spectroscopy
Opis:
The paper presents an analysis and practical study of the temperature and pressure influence on a non-dispersive infrared (NDIR) sensor for measuring the concentration of carbon dioxide in human breath. This sensor is used for monitoring patients’ carbon dioxide (CO2) in the exhaled air. High precision and accuracy of CO2 concentration measurements are essential in air sampling systems for breath analysers. They, however, require an analysis of the influence of the human exhaled air pressure and temperature on the NDIR CO2 sensor. Therefore, analyses of the changes in concentration were carried out at a pressure from 986 mbar to 1027 mbar and a temperature from 20°C to 36°C. Finally, corresponding correction coefficients were determined which allow to reduce the relative uncertainty of CO2 sensor measurements results from 19% to below 5%.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 803-812
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast high-impedance spectroscopy method using sinc signal excitation
Autorzy:
Kowalewski, M.
Lentka, G.
Powiązania:
https://bibliotekanauki.pl/articles/220740.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
impedance spectroscopy
sinc signal
Fourier transform
impedance analyzer
Opis:
In this paper the method of fast impedance spectroscopy of technical objects with high impedance (|Zx| ≥ 1 GΩ) is evaluated by means of simulation and a practical experiment. The method is based on excitation of an object with a sinc signal and sampling the response signals proportional to current flowing through and voltage across the measured impedance. The object’s impedance spectrum is obtained with the use of continuous Fourier transform on the basis of linear approximations between samples in two acquisition sections, connected with the duration of the sinc signal. The method is first evaluated in MATLAB by means of simulation. An influence of the sinc signal duration and the number of samples on impedance modulus and argument measurement errors is explored. The method is then practically verified in a constructed laboratory impedance spectroscopy measurement system. The obtained acceleration of impedance spectroscopy in the low frequency range (below 1 Hz) and the decrease of the number of acquired samples enable to recommend the worked out method for implementation in portable impedance analyzers destined for operation in the field.
Źródło:
Metrology and Measurement Systems; 2013, 20, 4; 645-654
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A multi-band integrated virtual calibration-inversion method for open path FTIR spectrometry
Autorzy:
Cięszczyk, S.
Powiązania:
https://bibliotekanauki.pl/articles/221293.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
FTIR
in situ spectroscopy
open path
process diagnostics
Opis:
This paper addresses problems arising from in situ measurement of gas content and temperature. Such measurements can be considered indirect. Transmittance or natural radiation of a gas is measured directly. The latter method (spectral radiation measurement) is often called spectral remote sensing. Its primary uses are in astronomy and in the measurement of atmospheric composition. In industrial processes, in situ spectroscopic measurements in the plant are often made with an open path Fourier Transform Infrared (FTIR) spectrometer. The main difficulty in this approach is related to the calibration process, which often cannot be carried out in the manner used in the laboratory. Spectral information can be obtained from open path spectroscopic measurements using mathematical modeling, and by solving the inverse problem. Determination of gas content based on spectral measurements requires comparison of the measured and modeled spectra. This paper proposes a method for the simultaneous use of multiple lines to determine the gas content. The integrated absorptions of many spectral lines permits calculation of the average band absorption. An inverse model based on neural networks is used to determine gas content based on mid-infrared spectra at variable temperatures.
Źródło:
Metrology and Measurement Systems; 2013, 20, 2; 287-298
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of the CRLC models describing the Helmholtz type cells for the nondestructive photoacoustic spectroscopy
Autorzy:
Chrobak, Ł. B.
Maliński, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/221397.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
nondestructive testing
photoacoustic spectroscopy
photoacoustic cells
Helmholtz cells
Opis:
The photoacoustic cell is the heart of the nondestructive photoacoustic method. This article presents a new simple lumped-components CRLC model of the Helmholtz type photoacoustic cell. This model has been compared with the well known literature models describing the Helmholtz type cells for photoacoustic spectroscopy. Experimental amplitude and phase frequency data obtained for the two photoacoustic cells have been presented and interpreted in a series of models. Results of the fitting of theoretical curves, obtained in these models, to the experimental data have been shown and discussed.
Źródło:
Metrology and Measurement Systems; 2014, 21, 3; 545-552
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wideband spectral emission measurements from laser-produced plasma EUV/SXR source based on a double gas puff target
Autorzy:
Arikkatt, Antony Jose
Wachulak, Przemysław
Fiedorowicz, Henryk
Bartnik, Andrzej
Czwartos, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/1849155.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Plasma Spectroscopy
X-ray coherence tomography
soft X-ray
Opis:
We present spectral emission characteristics from laser-plasma EUV/SXR sources produced by irradiation of < 1 J energy laser pulse on eleven different double stream gas puff targets, with most intense electronic transitions identified in the spectral range from 1 nm to 70 nm wavelength which corresponds to photon energy from 18 eV to 1240 eV. The spectra were obtained using grazing incidence and transmission spectrographs from laser-produced plasma emission, formed by the interaction of a laser beam with a double stream gas puff target. Laser pulses with a duration of 4 ns and energy of 650 mJ were used for the experiment. We present the results obtained from three different spectrometers in the wavelength ranges of SXR (1-5.5 nm), SXR/EUV (4-15.5 nm), and EUV (10-70 nm). In this paper, detailed information about the source, gas targets under investigation, the experimental setup, spectral measurements and the results are presented and discussed. Such data may be useful for the identification of adequate spectral emissions from gasses in the EUV and SXR wavelength ranges dedicated to various experiments (i.e. broadband emission for the X-ray coherence tomography XCT) or may be used for verification of magnetohydrodynamic plasma codes.
Źródło:
Metrology and Measurement Systems; 2020, 27, 4; 701-719
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurements of spectral spatial di stribution of scattering materials for rear projection screens used in virtual reality systems
Autorzy:
Mazikowski, A.
Trojanowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/220880.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
scattering distribution function
BSDF
virtual reality
CAVE
spectroscopy
luminance
Opis:
Rapid development of computing and visualisation systems has resulted in an unprecedented capability to display, in real time, realistic computer-generated worlds. Advanced techniques, including three-dimensional (3D) projection, supplemented by multi-channel surround sound, create immersive environments whose applications range from entertainment to military to scientific. One of the most advanced virtual reality systems are CAVE-type systems, in which the user is surrounded by projection screens. Knowledge of the screen material scattering properties, which depend on projection geometry and wavelength, is mandatory for proper design of these systems. In this paper this problem is addressed by introducing a scattering distribution function, creating a dedicated measurement setup and investigating the properties of selected materials used for rear projection screens. Based on the obtained results it can be concluded that the choice of the screen material has substantial impact on the performance of the system.
Źródło:
Metrology and Measurement Systems; 2013, 20, 3; 443-452
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
System of Optoelectronic Sensors for Breath Analysis
Autorzy:
Mikołajczyk, J.
Wojtas, J.
Bielecki, Z.
Stacewicz, T.
Szabra, D.
Magryta, P.
Prokopiuk, A.
Tkacz, A.
Panek, M.
Powiązania:
https://bibliotekanauki.pl/articles/221463.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
breath analyses
biomarkers
laser absorption spectroscopy
CEAS
MUPASS
medical screening
Opis:
The paper describes an integrated laser absorption system as a potential tool for breath analysis for clinical diagnostics, online therapy monitoring and metabolic disorder control. The sensors operate basing on cavity enhanced spectroscopy and multi-pass spectroscopy supported by wavelength modulation spectroscopy. The aspects concerning selection of operational spectral range and minimization of interference are also discussed. Tests results of the constructed devices collected with reference samples of biomarkers are also presented. The obtained data provide an opportunity to analyse applicability of optoelectronic sensors in medical screening.
Źródło:
Metrology and Measurement Systems; 2016, 23, 3; 481-489
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Examination of Sol-Gel Derived Hydroxyapatite Enhanced with Silver Nanoparticles using OCT and Raman Spectroscopy
Autorzy:
Głowacki, M. J.
Gnyba, M.
Strąkowska, P.
Gardas, M.
Kraszewski, M.
Trojanowski, M.
Strąkowski, M. R.
Powiązania:
https://bibliotekanauki.pl/articles/221475.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hydroxyapatite
sol-gel
nanoparticles
Raman spectroscopy
optical coherence tomography (OCT)
Opis:
Hydroxyapatite (HAp) has been attracting widespread interest in medical applications. In a form of coating, it enables to create a durable bond between an implant and surrounding bone tissues. With addition of silver nanoparticles HAp should also provide antibacterial activity. The aim of this research was to evaluate the composition of hydroxyapatite with silver nanoparticles in a non-destructive and non-contact way. For control measurements of HAp molecular composition and solvent evaporation efficiency the Raman spectroscopy has been chosen. In order to evaluate dispersion and concentration of the silver nanoparticles inside the hydroxyapatite matrix, the optical coherence tomography (OCT) has been used. Five samples were developed and examined ‒ a reference sample of pure HAp sol and four samples of HAp colloids with different silver nanoparticle solution volume ratios. The Raman spectra for each solution have been obtained and analyzed. Furthermore, a transverse-sectional visualization of every sample has been created and examined by means of OCT.
Źródło:
Metrology and Measurement Systems; 2017, 24, 1; 153-160
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detection of Gaseous Compounds with Different Techniques
Autorzy:
Mikołajczyk, J.
Bielecki, Z.
Stacewicz, T.
Smulko, J.
Wojtas, J.
Szabra, D.
Lentka, Ł.
Prokopiuk, A.
Magryta, P.
Powiązania:
https://bibliotekanauki.pl/articles/220919.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas sensors
laser absorption spectroscopy
CEAS
MUPASS
breath analyses
medical screening
Opis:
Sensing technology has been developed for detection of gases in some environmental, industrial, medical, and scientific applications. The main tasks of these works is to enhance performance of gas sensors taking into account their different applicability and scenarios of operation. This paper presents the descriptions, comparison and recent progress in some existing gas sensing technologies. Detailed introduction to optical sensing methods is presented. In a general way, other kinds of various sensors, such as catalytic, thermal conductivity, electrochemical, semiconductor and surface acoustic wave ones, are also presented. Furthermore, this paper focuses on performance of the optical method in detecting biomarkers in the exhaled air. There are discussed some examination results of the constructed devices. The devices operated on the basis of enhanced cavity and wavelength modulation spectroscopies. The experimental data used for analyzing applicability of these different sensing technologies in medical screening. Several suggestions related to future development are also discussed.
Źródło:
Metrology and Measurement Systems; 2016, 23, 2; 205-224
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł

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