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Tytuł:
Numerical Analysis of Sensitivity of SAW Structure to the Effect of Toxic Gases
Autorzy:
Hejczyk, T.
Pustelny, T.
Wszołek, B.
Jakubik, W.
Maciak, E.
Powiązania:
https://bibliotekanauki.pl/articles/177695.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface acoustics wave SAW
SAW
Ingebrigtsen’s formula
gas diffusion equations
gaseous acoustic sensors
numerical analyses of SAW structures
Opis:
The paper presents the results of numerical analysis of the SAW gas sensor in the steady and non-steady states. The effect of SAW velocity changes vs surface electrical conductivity of the sensing layer is predicted. The conductivity of the porous sensing layer above the piezoelectric waveguide depends on the profile of the diffused gas molecule concentration inside the layer. The Knudsen’s model of gas diffusion was used. Numerical results for the effect of gas CH4 on layers: WO3, TiO2, NiO, SnO2 in the steady state and CH4 in the non-steady state in recovery step in the WO3 sensing layer have been shown. The main aim of the investigation was to study thin film interaction with target gases in the SAW sensor configuration based on simple reaction-diffusion equation. The results of the numerical analysis allow to select the sensor design conditions, including the morphology of the sensor layer, its thickness, operating temperature, and layer type. The numerical results basing on the code elaborated numerical system (written in Python language), were analysed. The theoretical results were verified and confirmed experimentally.
Źródło:
Archives of Acoustics; 2016, 41, 4; 747-755
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy losses in big band saw machines – analysis and optimization
Autorzy:
Marinov, Boycho
Powiązania:
https://bibliotekanauki.pl/articles/949943.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
band saw machine
kinetic energy losses
optimization procedure
optimization solution
Opis:
In this paper, the energy losses in big band saw machines are investigated. These losses are caused by the geometric and angular inaccuracies with which the leading wheels are made. Expressions for calculating the kinetic energy of the mechanical system in the ideal and the real cases are obtained. For this purpose, expressions for calculating the velocities of the centers of the masses in two mutually perpendicular planes are obtained. A dependence for calculation of the kinetic energy losses of the mechanical system in final form is received. Optimization procedure is used to determine the values of the parameters at which these losses have minimum values. The proposed study can be used to minimize energy losses in other classes of woodworking machines.
Źródło:
Archive of Mechanical Engineering; 2020, LXVII, 3; 335-351
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emigration activity of the saw-toothed grain beetle Oryzaephilus surinamensis L. (Coleoptera: Silvanidae) in various environmental temperatures
Autorzy:
Klys, M.
Powiązania:
https://bibliotekanauki.pl/articles/65526.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
emigration activity
saw-toothed grain beetle
Oryzaephilus surinamensis
Coleoptera
Silvanidae
environment temperature
sawtoothed grain beetle zob.saw-toothed grain beetle
population dynamics
sex ratio
Opis:
The study pertained to the saw-toothed grain beetle Oryzaephilus surinamensis L., a dangerous pest of stored food products. The studies were carried out in the laboratory. Thermostats were set at a temperature of 31°C; an optimum temperature for this insect species, and in temperatures lowered to 28 and 22°C. The relative air humidity was kept at 60 ±5% relative humidity (RH). The main topic of the study was to examine the effect of lower temperatures in the environment, on the emigration activity of O. surinamensis. In these conditions, the population dynamics and the sex structure in O. surinamensis populations were also studied. The saw-toothed grain beetle was found to display very high emigration activity at 31 and 28°C. Lowering the temperature to 22°C caused a decrease in emigration activity and total inhibition of emigration activity until the 120th day of the experiment. A higher emigration levels among females rather than males, was also observed.
Źródło:
Journal of Plant Protection Research; 2012, 52, 4
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of airside aerodrome infrastructure by SAW method with weights from Shannons interval entropy
Autorzy:
Żak, Jolanta
Gołda, Paweł
Cur, Krzysztof
Zawisza, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/2067399.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
entropy
aerodrome infrastructure
SAW
Opis:
Multi-criteria decision support (MCDM) methods are widely used in many areas of science. This applies to economic, social and technical sciences. Implementing activities at the strategic, tactical or operational level requires appropriate tools to support decision-makers. The use of these tools requires the preparation of a decision model along with the formalization of the goal and the acquisition and preparation of data to make the decision accurate. Due to the wide application of MCDM in engineering practice, the article presents their application in air transport. It is an area that is constantly evolving, and all decisions at the strategic level have long-term effects and must be adequately justified. In the paper a compartmental extension of the classical SAW method with weights obtained using the compartmental Shannon entropy was proposed. This paper presents issues concerning the choice of airport layout and describes the problems that occur in determining the cost and capacity of airports. This paper reviews the literature on airport capacity and operations and airside air transport processes and the application of various multi-criteria decision support methods to airport problems. The main part of the article contains an optimization mathematical model aimed at determining the parameters of the elements comprising the airport, on the basis of which a simulation model was developed and a modified method of multi-criteria evaluation of SAW taking into account the interval numbers was presented, in which the set of weights was estimated by the Shannon entropy method. In the application part for 3 variants of the airport arrangement, the parameters were determined in the form of interval numbers and then evaluated using the presented method. The presented numerical example shows that the proposed method is an excellent tool to assist in solving complex decision problems where the data are imprecise and represented by interval numbers.
Źródło:
Archives of Transport; 2021, 60, 4; 171--185
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Modelling Studies of 400 MHz ST-X Quartz SAW Delay Lines for Potential Gas Sensing Applications
Autorzy:
Thirumal, V.
Raju, B.
Gandhi, P.
Pandya, H. M.
Powiązania:
https://bibliotekanauki.pl/articles/177740.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
surface acoustic wave
SAW delay line
impulse response model
equivalent circuit model
coupling-of-modes
COM model
SAW sensors
Opis:
Surface Acoustic Wave (SAW) devices like delay lines, filters, resonators etc., are nowadays extensively used as principal solid state components in many electronic applications and chemical vapour sensors. To bring out the best from these SAW devices, computational design and modelling are resorted too. The present paper proposes the modelling of 400 MHz ST-X Quartz based SAW delay line, by three models namely, Impulse Response Model (IRM), Crossed-field Equivalent Circuit Model (ECM) and Coupling-of-Modes (COM) model. MATLAB® is employed as a computational tool to model the experimental output of the SAW device. A comparative discussion of the modelled device results is also provided.
Źródło:
Archives of Acoustics; 2018, 43, 2; 153-161
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mixed Pseudo-orthogonal Frequency Coding for SAW RFID Tags
Autorzy:
Xu, M.
Xiao, X.
Yuan, Q.
Zong, Y.
Powiązania:
https://bibliotekanauki.pl/articles/176715.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
SAW RFID tag
OFC
POFC
Mixed-POFC
mixed pseudo-orthogonal frequency coding
COMSOL
Opis:
A mixed pseudo-orthogonal frequency coding (Mixed-POFC) structure is proposed as a new spreadspectrum technique in this paper, which employs frequency and time diversity to enhance tag properties and balances the spectrum utilization and code diversity. The coding method of SAW RFID tags in this paper uses Mixed-POFC with multi-track chip arrangements. The cross-correlation and auto correlation of Mixed-POFC and POFC are calculated to demonstrate the reduced overlap between the adjacent center frequencies with the Mixed-POFC method. The center frequency of the IDT and Bragg reflectors is calculated by a coupling of modes (COM) module. The combination of the calculation results of the Bragg reflectors shows that compared with a 7-chip POFC, the coding number of a 7-chip Mixed-POFC is increased from 120 to 144 with the same fractional bandwidth of 12%. To demonstrate the validity of Mixed-POFC, finite element analysis (FEA) technology is used to analyze the frequency characteristics of Mixed-POFC chips. The maximum error between designed frequencies and simulation frequencies is only 1.7%, which verifies that the Mixed-POFC method is feasible.
Źródło:
Archives of Acoustics; 2018, 43, 4; 681-687
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SAW sensor for detection of hydrocarbons. Numerical analysis and experimental results
Autorzy:
Hejczyk, T.
Urbańczyk, M.
Wituła, R.
Maciak, E.
Powiązania:
https://bibliotekanauki.pl/articles/201623.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
SAW
gas sensor
piezoelectric substrate
Ingebrigtsen's formula
impedance transformation law
numerical modeling
Opis:
The paper presents the results of numerical analyses of the SAW gas sensor in the steady and non-steady state. The effect of SAW velocity changes vs. the surface electrical conductivity of the sensing layer is predicted. The conductivity of the porous sensing layer above the piezoelectric waveguide depends on the profile of the diffused gas molecule concentration inside the layer. Knudsen's model of gas diffusion was used. Numerical results for the gases CH4, C2H4, C3H8, C6H6 in the steady state and CH4 in the non-steady state in the WO3 sensing layer have been shown. The results of numerical analyzes allow to select the sensor design conditions, including the morphology of the sensor layer, its thickness and operating temperature. Some numerical results were verified in experimental studies concerning methane.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 3; 589-595
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Deposition of Polymer Sensor Films on SAW Surface by Electrospraying Technology
Autorzy:
Jasek, K.
Pasternak, M.
Grabka, M.
Neffe, S.
Zasada, D.
Powiązania:
https://bibliotekanauki.pl/articles/177125.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Surface Acoustic Wave
SAW
gas sensors
deposition of chemosensitive films
Nafion® films
Opis:
One of the most important problems with regard to the Surface Acoustic Wave (SAW) gas sensors technology is the deposition of chemosensitive films exhibiting desirable chemical and physical properties. The electrospraying technology seems to be a very promising method of the film deposition in this case. It allows the chemosensitive layers to be obtained out of almost any chemicals and their mixtures in a controllable way. The process gives the possibility to generate specific films with properties unattainable if other methods were to be applied. For example, it allows to deposit solutions of polymers and suspensions of solids in polymer solutions which can degrade in the process of thermal evaporation deposition. The paper describes the results of experiments with electrospraying technique in order to obtain Nafion® films. The influence of the process parameters on film sensitivity has been studied.
Źródło:
Archives of Acoustics; 2017, 42, 3; 507-513
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of Surface Acoustic Wave Sensors for the Detection and Identification of Toxic Environmental Gases/Vapours
Autorzy:
Panneerselvam, G.
Thirumal, V.
Pandya, H. M.
Powiązania:
https://bibliotekanauki.pl/articles/176789.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
toxic gases
SAW
surface acoustic wave
SAW sensors
E-Nose
electronic nose
gas sensors
selective coating
Opis:
Detection and identification of toxic environmental gases have assumed paramount importance precisely in the defense, industrial and civilian security sector. Numerous methods have been developed for the sensing of toxic gases in the environment ever since surface acoustic wave (SAW) technology came into existence. Such SAW sensors called electronic nose (E-Nose) sensor use the frequency response of a delay line/resonator. SAW device is focused and given importance. The selective coating between input and output interdigital transducers (IDTs) in the SAW device is responsible for corresponding changes in operating frequency of the device for a specific gas/vapour absorbed from the environment. A suitable combination of well-designed SAW delay lines with selective coatings not only help to improve sensor sensitivity and selectivity but also leads to the minimization of false frequency alarms in the E-Nose sensor. This article presents a comprehensive review of design, development, simulation and modelling of a SAW sensor for potential sensing of toxic environmental gases.
Źródło:
Archives of Acoustics; 2018, 43, 3; 357-367
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Life table parameters of the parasitoid Cephalonomia tarsalis (Hymenoptera : Bethylidae) and its host the saw-toothed grain beetle Oryzaephilus surinamensis (Coleoptera : Silvanidae)
Autorzy:
Eliopoulos, P.A.
Powiązania:
https://bibliotekanauki.pl/articles/2084866.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biological control
demography
intrinsic rate of increase
stored products
Opis:
Biological parameters of the larval parasitoid Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) and its host the saw-toothed beetle Oryzapehilus surinamensis (L.) (Coleoptera: Silvanidae) were studied in the laboratory. The duration of the immature period, survival during development, as well as adult longevity and the number of progeny of both insects were recorded. Our data were used for the estimation of several demographic parameters and life table construction of both the host and the parasitoid. The wasp managed to complete its development (egg – adult) in 19.8 days at 25o C, whereas the adult female lived for 24.3 days. The host O. surinamensis demonstrated a longer developmental period (30.5 days) and adult female longevity (103.0 days). Female wasps laid an average of66.4 eggs throughout their lifetime whereas their beetle hosts laid five times more eggs (313.9). Life table parameters of C. tarsalis were estimated for the first time. The intrinsic rate of natural increase (rm) was 0.124 which was almost double that of its host (0.056). Our results are discussed on the basis of evaluating and improving the performance of C. tarsalis as a biocontrol agent against O. surinamensis in storage facilities.
Źródło:
Journal of Plant Protection Research; 2019, 59, 4; 544-551
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of the joints’ properties of thick-grained steel welded by the SAW and ESW methods
Autorzy:
Krawczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/353496.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
welding
properties of joints
fine-grained types of steel
non-destructive
destructive testing
optimizing a process of welding
Opis:
The article presents an analysis of properties of welded joints of thick-grained steel of P460NH type used more and more often in the modern constructions. A process of examining a technology of welding has been carried out on the thick-walled butt joints of sheet metal by two methods of welding namely submerged arc welding (SAW - 121) and electroslag (ESW - 722). The article deals with a topic of optimizing a process of welding thick-walled welded joints of fine-grained steel due to their mechanical properties and efficiency.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 1; 419-426
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis of the Joints’ Properties of Fine-Grained Steel Welded by the MAG and SAW Methods
Autorzy:
Krawczyk, R.
Powiązania:
https://bibliotekanauki.pl/articles/356147.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
welding
properties of joints
fine-grained types of steel
non-destructive
destructive testing
optimizing a process of welding
Opis:
The article presents an analysis of properties of welded joints of fine-grained steel of P460NH type used more and more often in the modern constructions. A process of examining a technology of welding has been carried out on the thick-walled butt joints of sheet metal by two methods of welding namely MAG – 135 and SAW – 121. The article deals with a topic of optimizing a process of welding thick-walled welded joints of fine-grained steel due to their mechanicalproperties and efficiency
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1641-1648
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrode Mass Loading Effects on Different Piezoelectric Substrates for Saw Delay Lines: A Comparative FEM Analysis
Autorzy:
George, Sheeja P.
Isaac, Johney
Philip, Jakob
Powiązania:
https://bibliotekanauki.pl/articles/2141693.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inter-digital transducers
surface acoustic wave devices
finite element analysis
numerical modelling and simulation
ANSYS
Opis:
Several modelling techniques are currently available to analyse the efficiency of inter-digital transducers (IDTs) fabricated on piezoelectric substrates for producing surface acoustic wave (SAW) devices. Impulse response method, equivalent circuit method, coupling of modes, transmission matrix method, and numerical techniques are some of the popular ones for this. Numerical techniques permit modelling to be carried out with any number of finger electrode pairs with required boundary conditions on any material of interest. In this work, we describe numerical modelling of SAW devices using ANSYS to analyse the effect of mass loading, a major secondary effect of IDTs on the performance of SAW devices. The electrode thickness of the IDT influences the resonance frequency of the SAW delay line. The analysis has been carried out for different electrode materials, aluminium, copper, and gold, for different substrate materials, barium titanate (BaTiO3), X-Y lithium niobate (LiNbO3), lithium tantalate (LiTaO3), and the naturally available quartz. The results are presented and discussed.
Źródło:
Archives of Acoustics; 2022, 47, 1; 89-95
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical and Experimental Analysis of the Response of a SAW Structure with WO3 Layers on Action of Carbon Monoxide
Autorzy:
Hejczyk, T.
Urbańczyk, M.
Pustelny, T.
Jakubik, W.
Powiązania:
https://bibliotekanauki.pl/articles/176885.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gas sensor
carbon monoxide (CO)
piezoelectric substrate
numerical modeling
surface acoustic waves
acoustoelectric effects
Ingebrigtsen's formula
Opis:
The paper presents the results of an analysis of gaseous sensors based on a surface acoustic wave (SAW) by means of the equivalent model theory. The applied theory analyzes the response of the SAW sensor in the steady state affected by carbon monoxide (CO) in air. A thin layer of WO3 has been used as a sensor layer. The acoustical replacing impedance of the sensor layer was used, which takes into account the profile of the concentration of gas molecules in the layer. Thanks to implementing the Ingebrigtsen equation, the authors determined analytical expressions for the relative changes of the velocity of the surface acoustic wave in the steady state. The results of the analysis have shown that there is an optimum thickness of the layer of CO sensor at which the acoustoelectric effect (manifested here as a change in the acoustic wave velocity) is at its highest. The theoretical results were verified and confirmed experimentally.
Źródło:
Archives of Acoustics; 2015, 40, 1; 19-24
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of performance of diamond wire saw with respect to texture characteristics of rock
Prognozowanie wydajności pracy strunowej piły diamentowej w odniesieniu do charakterystyki tekstury skał
Autorzy:
Ghaysari, N.
Ataei, M.
Sereshki, F.
Mikaiel, R.
Powiązania:
https://bibliotekanauki.pl/articles/220178.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
strunowa piła diamentowa
wydajność pracy
tekstura
diamond wire saws
production rate
texture coefficient
Opis:
In this study, prediction of production rate in diamond wire saw has been investigated. Performance measurements of diamond wire saw carried out in 7 different quarries of carbonate rocks in Iran. For determination textural properties, rock samples were collected from these quarries. At first, a thin section was prepared for each rock and then 5 digital photographs were taken from each section. After this, all images were digitized using AutoCAD software. Then, area, perimeter, longest diameter and shortest diameter were assigned. According to these parameters, all of the other textural characteristics and texture coefficient were determined too. The correlation between sawing rate and textural characteristics were evaluated using multiple and simple regression analyses. Then developed model was validated by P-value test. It was concluded that area, perimeter, diameter equivalent and index of grain size homogeneity are very effective on production rate. Production rate using diamond wire saw can reliably be predicted using developed model.
W pracy prognozowano wydajność pracy strunowej piły diamentowej. Badania wydajności prowadzono w 7 kamieniołomach na terenie Iranu, w których wydobywane są skały węglanowe. W celu określenia tekstury skał zebrano próbki wszystkich skał wydobywanych w kamieniołomach. Przygotowano zgłady i wykonano 5 fotografii cyfrowych każdej analizowanej próbki. Uzyskane obrazy poddano następnie obróbce cyfrowej przy użyciu oprogramowania AutoCAD. Określono następujące parametry: powierzchnia, obwód, najdłuższa i najkrótsza średnica. W oparciu o powyższe parametry przeprowadzono analizę tekstury i wyznaczono odpowiednie współczynniki. Korelację pomiędzy wydajnością pracy piły a właściwościami powierzchni (teksturą) określono przy użyciu prostej regresji liniowej oraz regresji wielokrotnej. Otrzymany model poddano następnie walidacji przy pomocy odpowiednich testów statystycznych. Stwierdzono, że pole powierzchni, obwód, równoważne średnice oraz wskaźnik jednorodności uziarnienia mają wpływ na wydajność pracy piły. Opracowany model może być skutecznie wykorzystywany dla wiarygodnego prognozowania postępu prac prowadzonych z wykorzystaniem piły diamentowej.
Źródło:
Archives of Mining Sciences; 2012, 57, 4; 887-900
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
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