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Wyszukujesz frazę "43.35.+d" wg kryterium: Temat


Tytuł:
High Performance of Electroacoustic Piezoelectric Ceramic Transducers
Autorzy:
Abd El-Ati, M. I.
Mosaad, M. M.
El-Baradie, B.Y.
Powiązania:
https://bibliotekanauki.pl/articles/1920644.pdf
Data publikacji:
1992-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
77.60.+v
Opis:
Lead zirconate-titanate containing 1 wt % niobium with different Zr/Ti ratios compositions were studied. A pronounced increase in densification during sintering process occurred near tetragonal-rhombohedral phase. Dielectric constant of polarized and unpolarized samples was studied. The rotation of all 90° domains to their original positions caused the more looseness of Ti$\text{}^{4+}$ and Zr$\text{}^{4+}$ in the octahedral configuration leading to greater polarization in the tetragonal structure, thus leading to, higher dielectric constant. Near the phase change, the minimum resonance frequency caused the minimum values of ultrasonic waves, which were emitted from the edge of the polarized ceramic transducers.
Źródło:
Acta Physica Polonica A; 1992, 81, 4-5; 527-533
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydration of the Zwitterionic Forms οf Amino Acids from the Acoustic Passynski Method
Autorzy:
Burakowski, A.
Gliński, J.
Powiązania:
https://bibliotekanauki.pl/articles/1811531.pdf
Data publikacji:
2008-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.Bf
43.35.+d
61.20.-p
61.20.Qg
Opis:
In this communication, we report the compressibility measurements made on amino acids in water at 25°C, compared with aqueous short-chained amines and carboxylic acids. The effect of the charge caused by protonation of the amino group and/or deprotonation of the carboxylic one was tested. The concept of additivity of the hydration number with the constituents of solute molecule was applied and discussed.
Źródło:
Acta Physica Polonica A; 2008, 114, 6A; A-39-A-44
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature Measurement by Statistical Parameters of Ultrasound Signal Backscattered from Tissue Samples
Autorzy:
Gambin, B.
Kruglenko, E.
Powiązania:
https://bibliotekanauki.pl/articles/1402186.pdf
Data publikacji:
2015-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
87.50.wp
43.35.+d
87.57.-s
Opis:
A novel estimation of temperature changes inside soft tissues has been proposed in sub-ablation range, i.e. ≈ 20°C-48°C. This estimation has been obtained by studying statistical properties of backscattered ultrasonic signals. Two different procedures of heating/cooling have been performed in which the RF echoes have been registered from soft tissue phantom in the first procedure, and from soft tissue in vitro in the second one. Calculated envelopes of signals registered in time points during heating/cooling experiments have been treated as a statistical sample drawn from a random variable with three different distributions, namely the Rayleigh distribution, the Nakagami distribution, and the K-distribution. The histograms obtained in subsequent time moments have been fitted to the three distributions. Dependencies of their shape and scale parameters on temperature have been calculated. It is concluded that the shape parameter of the K-distribution can be chosen as the best marker of temperature changes in both experiments. The choice of the marker has been made by analysis of temperature dependencies of all calculated parameters and by comparing the quality of fitting all histograms to the considered distributions. Besides, the chosen marker as a function of temperature exhibits the closest shape to temperature/time function experimentally measured.
Źródło:
Acta Physica Polonica A; 2015, 128, 1A; A-72-A-78
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solvation of Alcohols in n-Heptane and n-Propanol from the Acoustic Passynski Method
Autorzy:
Gliński, J.
Burakowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1811514.pdf
Data publikacji:
2008-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.Bf
43.35.+d
61.20.-p
61.20.Qg
Opis:
The method of Passynski of calculating the solvation numbers from compressibility was applied to solutions of short-chained normal alcohols in n-heptane and n-propanol. The dependences of solvation numbers on length of the solute molecules are surprisingly similar for both solvents. Applicability of the acoustic method for determining the solvation numbers in nonaquous systems, as well as for investigation of intermolecular interactions in them was proved. Some structural similarity of associated alcohol and hydrocarbon in liquid state is suggested.
Źródło:
Acta Physica Polonica A; 2008, 114, 6A; A-109-A-113
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Absorption and Dispersion of Ultrasonic Waves in n-Amylic Alcohol-Nitromethane Critical Mixture
Autorzy:
Hornowski, T.
Łabowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/1887536.pdf
Data publikacji:
1991-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
Opis:
Measurement of absorption and propagation velocity of ultrasonic waves as well as shear viscosity in n-amylic alcohol-nitromethane critical mixture are reported. Acoustic measurements were performed in the frequency range from 5 to 25 MHz and temperatures ΔT = T - T$\text{}_{c}$ from 0.1 to 12.3 K. An analysis of the results was carried out on the basis of a modified version of mode-coupling theory [10], which led to good agreement with experiment. The correlation length ξ$\text{}_{0}$ = 0.94 Ǻ is in agreement with the value obtained from optical measurements.
Źródło:
Acta Physica Polonica A; 1991, 79, 5; 671-682
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Absorption Coefficient and Propagation Velocity in Critical Benzonitrile-Isooctane Mixture
Autorzy:
Hornowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/1924274.pdf
Data publikacji:
1992-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
Opis:
Measurements of the absorption coefficient and propagation velocity of ultrasonic waves in critical benzonitrile and isooctane mixture are reported for the frequency range of 5-25 MHz and temperatures ΔT = T - T$\text{}_{c}$ from 0.15 to 20 K. The analysis of the experimental results is based on dynamic scaling theory leading to good agreement with the theoretical predictions, especially in the reduced frequency range 1 < ω* < 100. The adiabatic coupling constant g is calculated and compared to the experimental value.
Źródło:
Acta Physica Polonica A; 1992, 82, 6; 961-966
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dependence of Ultrasonic and Magnetic Hyperthermia on the Concentration of Magnetic Nanoparticles
Autorzy:
Kaczmarek, K.
Hornowski, T.
Bielas, R.
Żak, D.
Timko, M.
Józefczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/1030383.pdf
Data publikacji:
2018-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.75.-c
43.35.Cg
43.35.Wa
87.85.-d
Opis:
Hyperthermia treatment is the heating of tumor tissue up to temperatures between 41°C and 45°C, which trigger several physiological reactions in the body. Hyperthermia within tissue can be applied through various mechanisms. One of them is magnetic hyperthermia which uses superparamagnetic iron oxide nanoparticles (SPIONs) heated by an externally applied magnetic field. SPIONs can also be used as sonosensitizers in ultrasound hyperthermia increasing acoustic wave attenuation. The impact of SPION concentration on thermal effect during ultrasonic and magnetic hyperthermia was investigated in agar-gel phantom with added magnetite nanoparticles. The presence of nanoparticles in the tissue-mimicking phantom increases the thermal losses of ultrasound energy and temperature of the phantom.
Źródło:
Acta Physica Polonica A; 2018, 133, 3; 716-718
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficiency Measurements of Ultrasonic Generator for Welding
Autorzy:
Kardyś, W.
Milewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1401919.pdf
Data publikacji:
2015-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.20.Vj
43.35.-c
43.35.+d
77.65.Dq
77.84.Cg
85.50.-n
Opis:
The paper presents results of theoretical analysis as well as practical measurements of efficiency in ultrasonic welding system with main focus on ultrasonic generator. Through analysis and tests were performed using 3 kW 20 kHz Sonic Blaster ultrasonic generator manufactured by ITR. Special equipment was used to perform accurate measurements of input and output power of such generator since an output signal of the ultrasonic generator has high voltage amplitude up to 3 kV and frequency of 20 kHz. Artificial load able to dissipate up to 6 kW of continuous power was designed to simulate ultrasonic transducer. Power measurements were performed on the mains supply of the generator using accurate true RMS power meter and load side measurements were performed using specially built power metering system able to measure high voltage 20 kHz signals based on calibrated high voltage resistive divider and high frequency current transducer.
Źródło:
Acta Physica Polonica A; 2015, 128, 3; 456-460
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Universal Ultrasonic Generator for Welding
Autorzy:
Kardyś, W.
Milewski, A.
Kogut, P.
Kluk, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399360.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.20.Vj
43.35.-c
43.35.+d
77.65.Dq
77.84.Cg
85.50.-n
Opis:
The paper presents design and parameters of a multifunction ultrasonic generator manufactured by Tele and Radio Research Institute. Efficient usage of ultrasonic welding and cutting technology depends on the ability to precisely control process parameters and tune those parameters to suit particular needs. Ultrasonic generator is responsible for such control and tuning. Presented design incorporates powerful 32 bit Cortex M4 microcontroller with floating point unit which allows using modern signal processing methods to calculate parameters of ultrasonic stack in real time. Calculated parameters, especially impedance of the stack are used to estimate load level and identify phases of the welding process such as melting of the welded material. Precise control of the output signal is possible due to innovative design of the direct digital signal synthesis unit implemented in programmable logic device (CPLD). Resonant inverter topology of the generator front end ensures high electrical efficiency of the device. Designed generator is equipped with various communication interfaces such as USB host and slave, Ethernet, Bluetooth, CAN and RS485. Multiple digital inputs and outputs together with load cell interface, 4-20 mA receiver and 0-10 V analog input enable the generator to monitor and control entire ultrasonic welding system without the need of a PLC unit.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 456-458
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement System for Parameter Estimation and Diagnostic of Ultrasonic Transducers
Autorzy:
Kluk, P.
Milewski, A.
Kardyś, W.
Kogut, P.
Michalski, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399367.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.-c
43.35.+d
43.38.+n
43.38.-p
84.37.+q
07.10.-h
46.40.-f
07.20.Dt
Opis:
The paper presents an architecture and design of measurement system and methods for parameter estimation and diagnostic of ultrasonic transducers used in ultrasonic welding and cutting systems manufactured by Tele and Radio Research Institute. The key element of the ultrasonic welding and cutting system is a high power ultrasonic transducer implemented as a sandwich transducer consisting of a stack of piezoelectric ceramic rings mounted between two masses. High quality welding and cutting demand predetermined frequency characteristic of transducer impedance. Also important are: high energy efficiency, high coupling coefficient, low dielectric loss, and the optimal radiation pattern. In order to manufacture high quality and long-life transducers the piezoelectric rings must be selected and the sandwich transducers diagnosed on the basis of their measured parameters. Presented measurement system takes advantage of the virtual instrument technique in the NI LabVIEW environment. It uses Agilent U2761A Function Generator, U2531A Data Acquisition Unit, and the linear amplifier to measure impedance frequency characteristic in the frequency range of 10 kHz to 100 kHz. Moreover, the system can measure the vibration amplitude in the range of 1 μm up to 100 μm, using an optical sensor, and the temperature of the transducer using a pyrometer sensor.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 468-470
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Piezoceramic Transducers Selection Method for High Power Ultrasonic Devices
Autorzy:
Kluk, P.
Milewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1398757.pdf
Data publikacji:
2015-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
43.35.-c
43.35.Zc
43.38.Fx
43.38.+n
43.38.-p
Opis:
A universal method for selecting piezoceramic transducers used in high power ultrasonic devices such as ultrasonic welding and cutting systems has been presented. The key element of such systems is a high power ultrasonic sandwich transducer consisting of a stack of piezoceramic transducers mounted between two masses. Because of relatively large dispersion of piezoceramic transducer parameters between production lots, they must be selected in order to obtain a high quality and long-life sandwich transducer. Presented selection method consists of three stages. First, the parametric identification of the Butterworth-Van Dyke equivalent circuit model is performed based on piezoceramic transducer electrical impedance measurements. Next, the electrical impedance frequency samples are estimated using the identified Butterworth-Van Dyke model. Finally, the k-means clustering algorithm is used to select the best fitted piezoceramic transducer sets.
Źródło:
Acta Physica Polonica A; 2015, 127, 3; 719-722
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New Multimode Sonotrodes Models Designed for Rotary Ultrasonic Welding Systems
Autorzy:
Kogut, P.
Milewski, A.
Kardyś, W.
Kluk, P.
Gawryś, P.
Powiązania:
https://bibliotekanauki.pl/articles/1399374.pdf
Data publikacji:
2013-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.40.-r
43.40.+s
43.35.+d
43.38.+n
43.38.-p
46.40.-f
Opis:
The paper presents methods of designing sonotrodes, working in varied mechanical vibration modes in high power application regime such as rotary ultrasonic welding systems. The aim of the sonotrode design process is to optimize its shape to achieve the best energy efficiency for a given welding process. Sonotrode geometry influences the power transferred to the welded element because it determines the vibration amplitude distribution in the sonotrode. The most popular applications use sonotrodes designed for axial vibration. Conducted research have shown that the optimal displacement and strain distribution is achieved for sonotrodes working in various vibration modes such as axial, transverse, radial or their compositions. In the paper examples of multimode sonotrode models for various rotary ultrasonic welding technologies have been presented.
Źródło:
Acta Physica Polonica A; 2013, 124, 3; 474-478
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Wave Propagation Velocity in Nonconducting Liquids in an External DC Electric Field
Autorzy:
Łabowski, M.
Skumiel, A.
Hornowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/1887541.pdf
Data publikacji:
1991-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
Opis:
A theoretical analysis of variations in the propagation velocity of ultrasonic waves in liquid dielectrics in an external DC electric field was performed. Measurements of these variations in transformer oil in dependence on the field strength and temperature were made applying the phase method. To express the experimental results in graphical form numerical procedure of interpolation in Lagrange polynomials was used. The experimentally obtained variations in the velocity are compared with those predicted theoretically by the formulae derived.
Źródło:
Acta Physica Polonica A; 1991, 79, 5; 683-693
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Adiabatic Compressibility and Ultrasonic Relaxation in Aqueous Solutions of N, N-Diisopropylacetamide and Zinc Acetate
Autorzy:
Miecznik, P.
Powiązania:
https://bibliotekanauki.pl/articles/1931802.pdf
Data publikacji:
1994-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
Opis:
Measurements of velocity at frequency of 1 MHz and absorption coefficient of ultrasonic waves within the range 3-50 MHz in aqueous solutions of N,N-diisopropylacetamide (D-i-PA) and zinc acetate ((CH3$\text{}_{C}$OO)$\text{}_{2}$Zn) were made. Additionally, the density of the solutions was measured. The adopted method for making the solutions helped to change the ratio of the number of non-electrolyte molecules to that of electrolyte molecules, with a constant number of water molecules. Measurements of the velocity of ultrasonic waves in the solutions under study were conducted by means of an impulse-phase interferometer. Measurements of the absorption coefficient of ultrasonic waves were conducted by means of an ultrasonic high frequency system, type Matec Instruments (USA) Model 7700. All the measurements were conducted at a constant temperature of 20°C. On the basis of the analysis of excess functions of the molar volume and the adiabatic compressibility, the formation of solvatomers composed of [(D-i-PA)$\text{}_{2}$Zn(H$\text{}_{2}$O)$\text{}_{2}$]$\text{}^{2+}$ and [(D-i-PA)Zn(H$\text{}_{2}$O)$\text{}_{3}$]$\text{}^{2+}$ was found. Also the complex [Zn(CH$\text{}_{3}$COO)$\text{}_{4}$]$\text{}^{2-}$ can be recognised. The results of measurements of sound absorption indicate the occurrence of the relaxation process in the solutions under study and the frequency range used. On the basis of the relaxation theory, relaxation parameters of the process under study were calculated. The relaxation processes discovered in the system (D-i-PA)-H$\text{}_{2}$O(CH$\text{}_{3}$COO)$\text{}_{2}$Zn were assigned to the formation and disintegration of solvatomers composed of [(D-i-PA)Zn(H$\text{}_{2}$O)$\text{}_{3}$]$\text{}^{2+}$ and probably complexes mentioned before.
Źródło:
Acta Physica Polonica A; 1994, 86, 6; 895-906
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrasonic Studies of Intermolecular Interactions in System Methanol-N,N-Diisobutylformamide
Autorzy:
Miecznik, P.
Powiązania:
https://bibliotekanauki.pl/articles/1963258.pdf
Data publikacji:
1997-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.35.+d
Opis:
The ultrasonic velocity and density of methanol solutions of N,N-diisobutylformamide (DBFA) were measured at -5, 5 and 15° C over the entire concentration range. The compressibility, excess compressibility, partial molar compressibility, excess molar volume, partial molar volume were calculated. The concentration dependencies of the velocity and density are nonlinear. On taking account of the results for excess molar volume and excess molar compressibility, the minima of these functions are ascribed to the complex formation type CH$\text{}_{3}$OH:DBFA and CH$\text{}_{3}$OH:2 x DBFA. These complexes are formed by hydrogen bond between methanol and N,N-diisobutylformamide molecules. The strong changes in the concentration dependencies of partial molar volume and partial molar compressibility (within range 0...0.1 mol. fraction amide) show that methanol and DBFA have strong interactions in the low-mole-fraction regions, too.
Źródło:
Acta Physica Polonica A; 1997, 91, 3; 543-553
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

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