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1
Content available remote A Prototype for a Palm-sized Photoacoustic Sensing Unit
100%
Gao F. , Feng X. , Miao X. , Zheng Y.
X-Acoustics: Imaging and Sensing
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2014
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tom 1
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nr 1
EN
Photoacoustic sensing and imaging techniques have experienced tremendous research progress, ranging from fundamental physics and methodologies to various biomedical and clinical applications in recent years. However, the state-of-art photoacoustic systems still suffer from high cost and bulky size, which hinders their potential applications for low-cost and portable diagnostics. In this paper, we propose the design for a palm-size photoacoustic sensor prototype. The design’s lower cost and smaller size would allow it to be used for portable photoacoustic sensing applications like oxygen saturation and temperature. By converting the high-frequency photoacoustic pulse signal to low-frequency photoacoustic DC signal through a rectifier circuit, the proposed photoacoustic receiver could potentially reduce the cost and device size efficiently, compared with the conventional highspeed data acquisition card interfaced with computer solutions. Preliminary testing is demonstrated to show its feasibility for photoacoustic sensing applications.
2
Content available remote Detection of Ultrasound and Photoacoustic Imaging with Fiber Bragg Gratings
100%
Shuaiqi J. , Jianye S. , Nengzhu Z. , Lin H. , Jian R.
X-Acoustics: Imaging and Sensing
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2014
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tom 1
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nr 1
EN
In this paper, we explore a simple and effective fiber Bragg grating demodulation setup to detect ultrasound. Different frequency ultrasound from hundreds of kHz to several MHz were detected successfully. For the first time, we combine ultrasound from a PZT transducer with a photoacoustic imaging systemto obtain a clear photoacoustic image of our pencil lead sample. With the advantage of small size and all-optical features, this method has the potential to be applied to medical endoscopic examination in an electromagnetic environment. This preliminary study suggests that the ultrasound detection with fiber Bragg grating is both meaningful and feasible.
3
Content available remote Photoelectric and photothermal properties of selected II-VI mixed crystals
100%
Firszt F. , Łęgowski S. , Marasek A. , Męczyńska H. , Pawlak M. , Zakrzewski J.
Opto-Electronics Review
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2004
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tom Vol. 12, No. 1
161--164
EN
The paper presents investigations of optoelectric and thermal properties of ternary and quaternary II-VI mixed crystals Zn₀.₇Mg₀.₃Se, Zn₀.₈₈Be₀.₁₂Se, Zn₀.₈₃Mg₀.₁₃Be₀.₀₄Se, Zn₀.₈₆Mn₀.₀₈B₀.₀₆Se grown from the melt. The photoluminescence, photoconductivity and photoacoustic amplitude and phase spectra were measured. The energy gap and thermal diffusivity were estimated from photoacoustic spectra. Ionisation energies of defects responsible for observed photoconductivity were determined.
4
Content available remote Photoacoustic determination of the thermal diffusivity for thin metallic samples
100%
Łukaszewski K. , Pieszyński K.
Optica Applicata
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2004
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tom Vol. 34, nr 1
101-110
EN
The ratio of the signals produced in the photoacoustic cell for the front and back illumination of the metallic sample is analyzed. Both the theory and the experiment conducted prove that the slope of the frequency dependence of this ratio gives the measure of the sample’s thermal diffusivity.
5
Content available remote On the modulation frequency dependence of the photoacoustic signal for a metal coated glass-liquid system
100%
Marín E. , Vera-Medina G. , García A. , Calderón A.
Open Physics
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2010
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tom 8
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nr 4
634-638
EN
We show that the front photoacoustic signal due to a sample consisting of a glass plate with a metal coated surface, at which thermal waves are generated by periodical light absorption, enhances for certain modulation frequencies when the other glass surface is covered with a liquid sample. This contradicts the intuitive expectation based on the assumption that the liquid provides a new channel for heat conduction thereby decreasing the substrate temperature. Experimental results are shown and the described effect is explained using a thermal wave interference model.
6
Wykorzystanie metody spektroskopii foto akustycznej do badania starzenia materiałów elektroizolacyjnych.
88%
Żurawska A. , Szurkowski J.
Prace Naukowe Instytutu Podstaw Elektrotechniki i Elektrotechnologii Politechniki Wrocławskiej. Konferencje
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2006
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tom Vol. 44, nr 18
195-199
PL
W pracy przedstawiono wyniki wstępnych badań wykonanych metodą spektroskopii fotoakustycznej folii z poliereftalenu etylowego, poddanej wygrzewaniu. Uzyskane wyniki zachęcają do podjęcia dalszych badań nad możliwością opracowania nowej metody diagnozowania stopnia zestarzenia polimerów wykorzystującej efekt fotoakustyczny.
EN
The results of preliminary investigations of poly erephthalate ethyl obtained photoacoustic (PA) spectroscopy were presented. The use of the PA effect In the investigation of ageing degree of polymers hale been examined. Changes in the amplitude and phase of the PA signal with frequency have been measured in samples holed at a temperature 75 st. C at different lime.
7
Content available Laser photoacoustic diagnostics of advanced materials with different structure and dimensions
75%
Burbelo R. , Andrusenko D. , Isaiev M. , Kuzmich A.
Archives of Metallurgy and Materials
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2011
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tom Vol. 56, iss. 4
1157-1162
EN
In the article the results of practical implementation of the PA methods in the study of materials of different structure and dimensions are presented. The features of PA conversion in inhomogeneous semiconductor structures such as porous silicon and doped semiconductor materials are analyzed. To investigate the thermal and elastic properties of porous silicon's based composites gas-microphone and piezoelectric methods registration of PA signal were used. The results of theoretical and experimental investigation of PA conversion in inhomogeneous silicon-based semiconductor structures under their irradiation by short (~ 10 ns) laser pulse are presented. The influence of thermal parameters distribution of the material structure on the PA signal parameters is shown. Principal possibility of using pulsed radiation for investigation of the modified submicron surface layer is demonstrated.
PL
W pracy zaprezentowano wyniki praktycznej realizacji metod fotoakustycznych do badania materiałów o różnej strukturze i geometrii. Analizowane były aspekty konwersji fotoakustycznej w niejednorodnych strukturach półprzewodnikowych jak porowaty krzem i domieszkowane materiały półprzewodnikowe. Do badania termicznych i elastycznych właściwości kompozytów opartych na porowatym krzemie używano mikrofonowej, piezoelektrycznej metody fotoakustycznej. Przedstawione zostały wyniki teoretycznych i doświadczalnych badań konwersji fotoakustycznej przy użyciu krótkich impulsów laserowych (około 10 ns). Pokazano wpływ profilu przestrzennego materiałowych parametrów termicznych na sygnał fotoakustyczny. Przedstawiono także możliwości zastosowania metod impulsowych do badania submikronowych warstw powierzchniowych.
8
Content available Numerical Simulation of Breast Cancer in the Early Diagnosis with Actual Dimension and Characteristics Using Photoacoustic Tomography
75%
Ahangar Darband M. , Najafi Aghdam E. , Gharibi A.
Archives of Acoustics
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2023
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tom Vol. 48, No. 1
25--38
EN
A numerical study and simulation of breast imaging in the early detection of tumors using the photoacoustic (PA) phenomenon are presented. There have been various reports on the simulation of the PA phenomenon in the breast, which are not in the real dimensions of the tissue. Furthermore, the different layers of the breast have not been considered. Therefore, it has not been possible to rely on the values and characteristics of the resulting data and to compare it with the actual state. Here, the real dimensions of the breast at three-dimensional and different constituent layers have been considered. After reviewing simulation methods and software for different stages of the PA phenomenon, a single suitable platform, which is commercially available finite element software (COMSOL), has been selected for simulating. The optical, thermal, elastic, and acoustic characteristics of different layers of breast and tumor at radiated laser wavelength (800 nm) were accurately calculated or obtained from a reliable source. Finally, by defining an array of 32 ultrasonic sensors on the breast cup at the defined arcs of the 2D slices, the PA waves can be collected and transmitted to MATLAB software to reconstruct the images. We can study the resulting PA wave and its changes in more detail using our scenarios.
9
Content available remote Zastosowanie wibrometru laserowego do badań dyfuzyjności cieplnej materiałów stosowanych w elektronice
63%
Bychto L.
Przegląd Elektrotechniczny
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2014
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tom R. 90, nr 9
15-18
PL
Nowoczesne wibrometry laserowe o niespotykanej dotąd rozdzielczości, wynoszącej nawet 20pm [1], mogą znaleźć zastosowanie w badaniach właściwości cieplnych materiałów stosowanych w elektronice. Artykuł prezentuje próbę wykorzystania takiego wibrometru do wyznaczania dyfuzyjności cieplnej materiałów takich jak krzem, german i krzemogerman.
EN
Modern laser vibrometer of unprecedented resolution of even 20pm [1] may be used in studies of thermal properties of materials used in electronics. This article presents an attempt to use of such vibrometer to determine thermal diffusivity of the materials such as silicon, germanium and silicon-germanium.
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