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This study compares the power dissipation and temperature profile in a single element acoustic transducer as a result of two of the most common representations of loss in piezoelectric materials. The first model, described in the IEEE Standard on Piezoelectricity, represents losses using the mechanical quality and the dielectric loss. The second model, described by Holland, represents loss through complex material constants. The difference between these representations is quantified by using the 1D Mason model to simulate the power dissipation in the transducer. The result of this study shows that there is a discrepancy in the power dissipation and therefore temperature profile between the two different representations. This study concludes that mixing the two representations can drastically affect the estimated power dissipation.

The pelvic floor muscles (PFM) consist of pubococcygeus, ileococcygeuys, coccygeus and puborectalis muscles. The pubococcygeus and puborectalis muscles have been collectively called as the pubovisceralis muscle, due to the difficulty to differentiate these muscles [1]. Pelvic floor dysfunctions — such as urinary incontinence (UI) and pelvic organ prolapse (POP) — can be associated with different risk factors. The most common risk factors responsible for these changes are vaginal delivery, hormonal changes, obesity, aging, among other, affecting the biomechanical behavior of the PFM [2]. In this sense, the mechanical characteristics of the female pelvic floor are relevant to understand the pelvic dysfunctions. The aim of the present work is to present distinct values of the material constants of the Yeoh hyperelastic constitutive model applied to pubovisceralis muscle of two women — one with POP and other without pathology. For this purpose, we used an optimization scheme, involving an inverse finite element analysis (FEA) and Powell's algorithm, using input information non-invasively (Magnetic Resonance Imaging (MRI)).

This paper is aimed at examining the validity of material constants reported for the use in surface acoustic wave (SAW) device simulations. At first, based on the full set of material constants calculated by the first principle, bulk acoustic wave (BAW) velocities are calculated for Sc x Al 1−x N and compared with published experimental results. Then, the effects of Sc x Al 1−x N material constants with different Sc contents on acoustic characteristics are calculated and the influences of shear vibrations on SAW characteristics are recognized. Then series of SAW devices are fabricated on Sc x Al 1−x N film/Si substrate structure with various Cu and ScAlN thicknesses h Cu and h ScAlN , respectively, and measured variations of phase velocity V and effective electromechanical coupling factor K e 2 with these parameters are compared with the calculation. The fairly well agreed results indicate a reliable set of Sc x Al 1−x N material constants for SAW device simulations.

The langasite crystal has the capability of no phase change at temperatures exceeding 600°C for high temperature applications. Since the material properties of langasite were measured usually at 25 0C as the reference temperature they are no longer accurate at high temperature environments. We employ a Lagrangian formulation to investigate the temperature behavior of thickness vibrations of langasite in a wide temperature range from 25°C to 600°C. The analysis only requires the elastic constants and their effective temperature derivatives of elastic constants and thermal expansion coefficients to predict the material constants at any given temperature. Based on the new values of the elastic constants and thermal expansion coefficients, the zero-valued temperature coefficients of frequency are investigated. The presently identified temperature compensated crystal cuts of the thickness-shear modes of langasite at different temperatures were compared with those at reference temperature and also with some cuts found in the literature.

Currently, it is required to develop lead-free piezoelectric thin film materials such as (K,Na)NbO 3 (KNN) for a substitute of Pb(Zr,Ti)O 3 (PZT). However, the material constants of a KNN film have not been reported yet. In this paper, some material constants of a KNN film are presented for the first time. We fabricated some piezoelectric resonators using a blanket KNN film by MEMS (micro electro mechanical systems) technology, and obtained the following material constants and related values; s 11 E = 9.27 pm2/N, s 12 E = −3.06 pm2/N, s 66 E = 24.7 pm2/N, c 33 E = 2.89 GPa, k 31 2 = 0.06%, k t 2 = 2.08%, d 31 = −78.9 pC/N, Poison ratio σE = 0.33, and e 33 T/e 0 = 1.27×103. We also measured the velocities of leaky Lamb wave in a KNN diaphragm covered with Al using a line-focus-beam ultrasonic material characterization (LFB-UMC) system. Phase velocities of 1491 m/s and 5370–5180 m/s were measured for antisymmetric (A 0 ) and symmetric (S 0 ) modes of leaky Lamb wave, respectively. This is an important step to the determination of full material constants of the KNN film.

Accurate sets of material constants and temperature coefficients are required to develop high temperature SAW sensors. It was previously shown that SAW Fractional Frequency Curve measurements combined with numerical optimization could help ease the burden of the experimental determination of some of these coefficients. To determine the other “missing” coefficients, it was suggested to use complementary BAW FFC measurements. However, to keep the global experimental effort as low as possible, a solution had to be found to avoid fabricating additional BAW devices on special LGS orientations. In this work, we describe a practical solution to simultaneously acquire BAW and SAW FFCs. Experimental results are presented then used to compute values of some of the missing coefficients. This demonstrates the whole method as being a promising way to determine accurate temperature coefficients with reduced experimental effort.

The full material constants of a 40% Sc-AlN thin film were systematically determined. First, 4 kinds of MEMS resonators and a Lamb wave resonator were used to determine the material constants as much as possible. The other unknown material constants together with the material constants which needed more accurate estimation were determined based on ultrasonic microspectroscopy and parameter fitting. The phase velocity versus frequency (v-f) characteristics of A 0 and S 0 mode leaky Lamb waves in a self-suspended ScAlN film were measured using an ultrasonic microscope, and then theoretical v-f characteristics were fitted to the measured ones by tuning the material constants as parameters.

Skin biomechanics has become an emerging area in research as its interest covers a wide range of applications such as product design, surgery, animation and materials engineering. Based on literatures, silicone rubber is one of the best candidate materials that exhibit desirable skin characteristics, thus making it the right material for skin substitute. Nonetheless, there is no specific standard that has been used to measure the mechanical properties and deformation behaviour of synthetic skin. This paper for the first time aims to assess two standard testing methods for silicone rubber. The work is carried out in 2 stages involving uniaxial testing and quantifying the material constants using a Matlab programme. Mechanical tests are conducted on 2 types of materials (different grades of silicone rubber) using uniaxial tensile test with two different standards (ASTM D2209 and ASTM D412). The raw testing data (load-extension) are then input into an in-house developed Matlab programme to compute and plot stress-stretch value based on neo-Hookean model. Based on statistical analysis, the testing data is found valid, since the sample variance is found to be less than 1%. The neo-Hookean constants, C1, are found to be 0.7819 (ASTM D2209) and 1.3786 (ASTM D412) for Material 1; and 0.927 (ASTM D2209) and 1.4396 (ASTM D412) for Material 2 revealing a difference of 59.67% and 51.21% for Material 1 and Material 2 respectively. As a conclusion, the significant difference of the quantified Material constants suggests a dedicated testing standard must be used.

We have successfully grown high quality large size piezoelectric single crystals of Ca3TaGa3Si2O14 (CTGS) by the Czochralski technique. The elastic material constants were derived from bulk- and surface acoustic wave measurements. Starting with the elastic constants determined from BAWs we optimized the data set by measuring SAW velocities as a function of propagation angle. Dielectric and piezoelectric constants were also obtained.

During long time for the analysis of the mechanical oscillations of the solid samples with finite sizes and for determination of their material constants the variational method was widely used. However the calculations have been performed without considering the loss of the energy of the mechanical oscillations. In this paper the experimental study of the frequency dependence of the real and imaginary parts of the electrical admittance of the piezoelectric samples having the cube form was carried out in order to determine the resonant frequencies of the mechanical oscillations and estimate their Q-factors. Then we performed the theoretical analysis of these oscillations by the variation method and made the comparison of the theoretical data with experimental one. This allowed us to find the coefficients of viscosity, which was considered as only source of the mechanical loss for the samples of piezoceramics of PZ27, PMN34.5%PT, and PZ26.

In this paper, we incorporate two thermal models with periodic FEM/BEM to analyze the temperature-frequency behavior of SAW under periodic IDT. One is the classical model based on Campbell's theory, which has been widely used. We find that this model fails to predict temperature-frequency behavior of SAW for some cases, although we can get accurate results for many cases of some cuts and modes by using this model. The other is based on piezoelectric, Lagrangian equations. This one his proved to be a general model for the analysis of thermal effects on SAW, and is more accurate than the first one. But the application of this model is limited to quartz-based devices, because the temperature coefficients of material constants for other materials for piezoelectric, Lagrangian equations are not available at present. In practice, the two models are useful for the designing of SAW devices.

A detailed study of the scale transition in the asymptotic multiscale analysis of heterogeneous solids is presented. Through a one-dimensional periodic model problem with analytical solution, the micro scale analysis of unit cell and coarse-graining analysis for homogenized material constants, especially the scale transition, are discussed in details. The relationship between the asymptotic expansion multiscale method and variational multiscale method is also illustrated. Meanwhile two dimensional numerical experiments are performed to justify the unit cell performance for periodic problems.

For dielectric constants, only e13 was significantly changed during correction prosess. This is because e13 is small and have low influence on to capacitance. Mostly changed elastic constants are s12 and s23. Such a big change is due to low accuracy for these constants in resonance-antiresonance method. A mean for other constants change is about 6 %. Mostly changed piezoelectric constants are d31 and d32. Differences between measured and calculated SAW parameters are lower for corrected material constants.

Based on the complex variable method and Stroh formalism, this paper studied the stress and electric displacement field distribution of a functional graded piezoelectric matrix with a piezoelectric fiber. According to the continuous conditions between the piezoelectric matrix and the fiber and using the method of piece-wise homogeneous layers, the stress and electric displacement field of any functional graded piezoelectric matrix are derived. And the stress and electric displacement field of any functional graded piezoelectric matrix properties are analyzed. It is shown that the stress and electric displacement field are greatly affected by the property of matrix and variation of material constants of the matrix property.

In this paper, we fabricated several samples using Amorphous metal powder and Sendust as magnetic loss materials and CPE as binder. Firstly, we fabricated EM wave absorber with different composition ratio of 60 ∶ 40, 70 ∶ 30 and 80 ∶ 20 wt.%. and thickness of 1 mm and 2 mm. Then we compared the measured absorption ability based on measured data from samples. We calculated loss tangent from material constants obtained by using l - 2l method. It was shown that composition ratio with 80 ∶ 20 is suitable for EM wave absorber for RFID system, and EM wave absorber fabricated with amorphous metal powder shows better absorption ability than EM wave absorber fabricated with Sendust.

In the present work the applied, two-dimensional micropolar theory of thermoelasticity for plates and the applied, one-dimensional micropolar theory of thermoelasticity for bars are constructed on the basis of three-dimensional equations of the asymmetric theory of elasticity in a sphere of three-dimensional thin plate (in a cylinder of a small height) and two-dimensional equations of asymmetric theory of thermoelasticity in a sphere of thin rectangle with the help of the asymptotic method. The micropolar boundary layers are constructed and studied. The problem of mating of the interior problem (of the applied theory) and the boundary layer problem is studied in the result of which the boundary conditions of both the applied theory of micropolar plates and bars and of boundary layer problems are obtained. Depending on values of elastic material constants, two applied theories are constructed - the applied theory of micropolar plates (bars) with independent fields of displacement and rotation and the theory with the constraint rotation. Some definite problems are studied on the basis of the constructed applied theories of micropolar thermoelastic plates and bars. The studied problems are brought to the final numerical results on the basis of which the effects related to a micropolar material are discussed. The spheres of applicability of the constructed theories of micropolar plates and bars are discussed too

Lanthanum calcium oxoborate, LaCa/sub 4/O(BO/sub 3/)/sub 3/ (LaCOB), single crystals were grown by the Cz technique. The material constants and SAW properties of the LaCOB crystal were evaluated. The LaCOB crystal belongs to point group m. Since the measurement process of the material constants in point group m has not been reported, we established a new measurement process including vibration modes and crystal substrates in point group m based on that in point group 2, which has been already described (Mason (1946)). Using the new measurement process, all the material constants of the LaCOB crystal at 25/spl deg/C were determined by the resonance-antiresonance method. Moreover, by characterization of the SAW and pseudo-SAW (PSAW) on the X-, Y- and Z-cut substrates, a maximum coupling factor (k/sup 2/ = 0.6%) was observed on the Z-cut crystal at the Y-axis propagation, and a relatively low temperature coefficient of delay (TCD) (48 ppm/K) was observed on the Y-cut crystal at the Z-axis propagation.

Theoretical results have shown the potential usefulness of Ca/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/ (CNGS) crystals for surface acoustic wave (SAW) applications. The existence of orientations of CNGS with zero temperature coefficient for SAW has been predicted on thin material constants determined by the present authors. Thin simulation has been carried out so that the temperature-compensated Rayleigh SAW is located around a (30/spl deg/, 45/spl deg/, 110/spl deg/) substrate with v of 3120m/s, and k/sup 2/ of 0.46%.

We investigated the correlation between the peak SAR and the maximum temperature increase in the models of infants and adults for exposure to a dipole antenna. Numerical results show that the maximum temperature increases in the head and brain were reasonably proportional to the peak SAR in the corresponding regions. No clear difference in the correlation between the peak SAR and the maximum temperature increase was observed for infant and adult models. Additionally, the effect of the material constants on the correlation was at most 10%.

We have determined the material parameters of SNGS (Sr/sub 3/NbGa/sub 3/Si/sub 2/O/sub 14/). The elastic material constants were derived from bulk acoustic wave (BAW) measurements and surface acoustic wave (SAW) measurements. Starting with the elastic tensor determined from BAWs we optimized the data set by investigating the influence of the elastic tensor components on the angular dispersion of SAW. The electromechanical coupling coefficient was derived from SAW measurement on open and short-circuited Y-cut. Additionally we measured dielectric parameters.

In this paper, we report on our study of stress-induced effects on thickness vibrations of a langasite plate. The plate is assumed to be doubly-rotated, specified by angles /spl phi/ and /spl theta/. The stresses are assumed to be uniform and planar. The first-order perturbation integral as developed by Tiersten for frequency shifts in resonators is used. The dependence of frequency shifts on /spl phi/ and /spl theta/ is calculated and examined, and loci of stress-compensation are determined. The analysis makes use of the third-order material constants that are available for langasite but not for its isomorphs.

A cartilage growth mixture theory is presented and used to illustrate how a mechanical model of cartilage growth may be used to quantify the evolving compositional and mechanical properties of developing bovine articular cartilage. Model parameters that describe the kinematics of growth, the stress tensors, and material constants are determined using existing experimental data at three developmental stages. The results describe how the intrinsic properties of the collagen network change during growth, with stiffening of the collagen network from the mid-third trimester fetal stage to the newborn calf and young adult stages.

The paper presents an evaluation of the temperature coefficients of elastic constants of langasite on both BAW and SAW delay-temperature dependence data. Least squares method is used to fit the temperature coefficients of the elastic constants of langasite to the measured BAW and SAW temperature coefficients of delay of the first order (TCDI). For sufficient decrease of computation time, the perturbation procedure is employed. That allows us to fit optimally the constants of crystals in order to get the coincidence with experimental BAW and SAW delay-temperature data using only 1 iteration step in a computer.

The linear combinations of the fundamental material constants of third-order piezoelectricity and electrostriction of quartz have been determined; they were obtained by the last-squares fit to over 100 observations of the changes in the resonance frequency of the thickness modes of quartz plates caused by a DC field (the resonator method). With one exception, there is a very good agreement between the present results and their counterparts obtained independently by the transit-time method (pulse propagation in bulk quartz); the differences between comparable constants are no longer out of proportion with their standard errors. >

A nonlinear least-squares algorithm to determine the material constants of LiNbO/sub 3/ from primary SAW (surface acoustic wave) velocity measurements is shown. If the values of the mass density and the unclamped permittivities are known at least to some accuracy, all 13 independent elastic, piezoelectric, and dielectric constants are obtained with high precision. While measurements on Y-cut LiNbO/sub 3/ do not provide enough information to perform this task, the SAW velocities on 128 degrees -rot-Y-cut LiNbO/sub 3/ are sensitive to all material constants. This method is not restricted to LiNbO/sub 3/ only, but can be applied to other strong coupling materials (e.g. LiTaO/sub 3/) as well. >

The various reported values of the material constants of interest for surface acoustic wave (SAW) device applications are summarized in tabular form. For the user community, those sets of constants are identified from which SAW design calculations can reliably be made, as well as those sets of constants requiring further refinement. The relevant material constants include: mass density, elastic stiffness, piezoelectric stress, dielectric permittivity and the thermal expansion coefficients. Only data published after 1978 are included. >

Standard errors of the third-order nonlinear material constants of quartz obtained by the least-squares fit reflect only the random errors from a single source. The source is the experimental data set used to determine the nonlinear constants. Other possible sources of errors, namely the linear material constants and the crystal specimen orientation, are reported. To minimize their effect, the most important factor is the accuracy of the linear elastic constants. If these constants have standard errors of 1%, they produce nontrivial errors in the nonlinear constants, about half the size of the errors due to the experimental errors. It appears that the errors caused by the other linear constants and by the orientation angles are of substantially lesser importance. >

We recently demonstrated large second harmonic surface emission cross-sections in a nonlinear anti-resonant reflecting optical waveguide (NARROW). High efficiencies were obtained in thick films by simultaneously maintaining the anti-resonance conditions at the 1.06 /spl mu/m fundamental in the multilayer film and the harmonic 0.53 /spl mu/m resonance. Here we report on a full optimisation process, taking all material constants, linear and nonlinear, into account and optimising the thickness ratio and composition of each layer in the system. >

Conducting polymer/solid polyelectrolyte actuating structures designed for realising steerable microcatheters are presented. They exploit the electromechanochemical phenomena of /spl pi/-electron conjugated conducting polymer occurring when ionic species are exchanged with the surrounding solid polyelectrolyte. Experimental determination of the governing material constants, modelling of the composite material and finite element computer simulations of the mechanical properties of cylindrical structures provide favourable indication about the feasibility of effective steerable, miniaturised catheters. Simulations about 2-3 Fr endoscope tips show that a degree of bending of about 30 and a developed distal force of about 4 gr can be obtained, The device would possess high potentialities for intravascular explorations and robotic-like diagnostic or surgical minimally invasive operations.

The transformer ratio and capacitance in an equivalent circuit for an interdigital surface acoustic wave transducer are presented in general form. The relation between these parameters and the input admittance for one periodic section of the equivalent circuit is calculated. Using these calculated values and the admittance formula of H. Engan (1975), the parameters are finally determined as a function of metallization ratio, harmonic number, and material constants. The results are verified by experiments. >

Measurements of SAW (surface acoustic wave) velocities on the entire surface of free and metallized substrates of 128 degrees rotY-LiNbO/sub 3/ are reported. The influence of mechanical loading is examined. All experimental data are given as trigonometric expansions. Improved sets of material constants for LiNbO/sub 3/ and LiTaO/sub 3/ are calculated by fitting them to the experimentally determined SAW velocities. In agreement with R. Graham (1977), a significantly larger value of e/sub 33/ was found for LiNbO/sub 3/. While all material constants of LiBnO/sub 3/ and most of LiTaO/sub 3/ have reasonable error bounds, further improvements are expected from more accurately measured unclamped permittivities. >

Langasite (LGS), like quartz is a trigonal class 32 material. It has been successfully grown and is generally considered to be very promising for surface wave devices since it has a larger electromechanical coupling than quartz and some zero temperature coefficients of frequency (TCF) and delay (TCD for saw) orientations have been found. Its detailed velocity, coupling, TCF, TCD, and power flow characteristics are not yet fully known and since there exist different sets of material constants in the literature there are significant differences in the properties predicted by different researchers. In this paper the focus is on the pseudosaw (PSAW) and high-velocity pseudosaw (HVPSAW) properties of some rotated cuts of LGS. In this paper the velocities, electromechanical coupling constants, and attenuation properties are described for various cuts for the SAW, PSAW, HVPSAW modes. Some low attenuation and high coupling cuts will be described. For rotated Y-cuts very low loss PSAW orientations are found whereas the HVPSAW attenuation is very high for all rotated Y-cuts. Some orientations where the PSAW velocity approaches the bulk fast-shear velocity asymptotically and the loss becomes insignificant over an appreciable range of angles, are also discussed.

This paper discusses the use of complex material constants to model the response of piezoelectric materials to alternating fields. The various material constants needed to describe the behavior of piezoelectric materials in transducers are introduced. The reasons for using complex coefficients to characterize the frequency dependent dielectric, elastic and piezoelectric response of such materials are discussed. Several interpretations of the complex coefficients are reviewed.

Based on Tiersten's analysis an accurate calculation of the coupling coefficient dependence on geometrical dimensions and mass-loading for quartz and langasite monolithic structures was performed. We have studied the effect of mass-loading on the coupling coefficient of langasite and quartz monolithic filters and we have found that the effect on langasite filters is tower than on quartz filters. A better agreement between input data and experimental attenuation characteristics is obtained when the rigorous theoretical approach is used in the calculation of the coupling coefficient. The relation between the coupling coefficient and the material constants is discussed on crystals grown by various laboratories.

There were three foci of this study. The first was a delineation of the effect of two variables on the tensile properties of human Achilles tendon, To that end, the values of the ultimate tensile strength, UTS, strain at the UTS point, /spl epsiv//sub max/ and tangent modulus of elasticity, E/sub T/, of cadaveric Achilles tendon were obtained as a function of (a) donor age (36 to 100 y), at a fired loading rate of 10 %/s; and (b) loading rate (for tendons from the 52to 67-year-old donor group). The second focus was the presentation of a suitable constitutive relation between the tensile stress, /spl sigma/, and the tensile strain, /spl epsiv/, for this tissue. The aim of these two foci was to provide information that will aid in the selection of Achilles tendon for the repair of ruptured Achilles tendons as well as anterior cruciate ligaments (ACLs). The third focus was, thus, a comparison of the tensile properties of Achilles tendon and patellar tendon, which is now widely used for the repair of ruptured ACLs. It was found that: (a) age exerts a marked effect on UTS, an insignificant one on /spl epsiv//sup max/ and a moderate one on E/sub T/; (b) a ten-fold increase in loading rate results In a moderate but insignificant increase in UTS, a significant decrease in /spl epsiv//sub max/, and a significant increase in E/sub T/; (c) a suitable constitutive relation is /spl sigma/=C/spl epsiv/exp[D/spl epsiv/+F/spl epsiv//sup 2/], with C, D, and F being material constants; and (d) the tensile properties of Achilles and patellar tendons have similar values.

The aim of this paper is to derive an improved set of Langasite (LGS) material constants based on BAW and SAW data in order to get a better agreement between theoretical predictions and experimental measurements for wave velocities and temperature effects. In a previous work it was shown that an "aggregate" set of the measured values of bulk wave velocities can provide a improved set of measurement data for BAW propagation. Recent advances in LGS crystal growth and measurement of material properties obtained independently from the original authors allows us to go further, one unsolved problem with previous data being inconsistencies in the temperature derivatives of material constants of LGS. This paper brings together a large quantity of experimental data obtained independently by the authors. Comparison between experiments and theoretical predictions are recomputed taking into account the more recently published data sets for LGS. In combination with a critical analysis of the literature on LGS crystals, an improvement of a "best fit" data set for velocities is proposed.

We numerically studied the f-T behavior of the fundamental TS fast mode in a partially plated X-cut LiTaO/sub 3/ strip resonator. Using the material constants measured by Smith and Welsh [1971], the f-T curves were calculated as a function of the electrode-length and the plate-length direction /spl psi/. The results confirmed that the turnover temperature of f-T curve decreases with increasing the electrode length. Furthermore we found out that the turnover temperature changes according to the coupling between TS and TF modes through c/sub 56/, and that it therefore depends on the plate-length direction /spl psi/. An angle /spl psi/=40/spl deg/ that yields the turnover temperature in the range of 33/spl sim/6.5/spl deg/C is optimal for the material constants of Smith and Welsh because c/sub 56/ is zero. We also showed that the external loading of both series and parallel capacitances can make the adjustment of turnover temperature very flexible.

The paper deals with the critical evaluation of the methods used in our previous papers concerning the determination of the high-order material constants in the quartz. We have determined the effective elastic constants of 4th order using a measurement of the intermodulation products, and measurement of drive level dependence of resonant frequency of quartz resonators. The computer based-method of solution of the set of equations gives an access to obtain the effective non-linear stiffnesses of 4th order. The measurements and computer solutions are performed on different Y-cuts resonators, both for quartz and gallium phosphate resonators, vibrating in fundamental thickness shear mode. The experimental results are discussed.

Since the first publication of material constants of langasite (LGS) and their temperature coefficients, a careful examination of the progression of reported values shows that they appear to be converging toward a "best" set of material constants. In this work, an "aggregate" set of the measured values of bulk wave velocities is used in order to provide a "best" set of measurement data for BAW propagation. A "best" set of material constants is extracted from this data, in conjunction with the aggregated dielectric constant and lattice constant data. This new set of material constants is able to predict wave velocities to better than 0.5% for most orientations.

The numerical calculations using new material constants were in good agreement with the experimental results of the temperature-related SAW properties on the langasite substrate with Euler angle (0°,140°,φ). The temperature-related SAW properties as a function of the IDT metal thickness were also experimentally investigated. It was revealed that a thicker metal leads to a lower turnover temperature. Furthermore we investigated the NSPUDT (natural single phase unidirectional transducer) properties of langasite with Euler angle (0°,140°,25°) experimentally. Its directivity was almost equal to one estimated by the calculation based on the coupling of mode (COM) model. This NSPUDT property is a promising feature for the low-loss IF filter.

The electrical field strength induced in tissues depends upon the constants of the material of the radiator. The magnetic permeability increases the strength of the near field, and the conductivity decreases it. A radiator with a certain shape and certain dimensions can be composed of various materials. For various combinations of materials, different field patterns are obtained. Thus the SAR patterns can have either sharp changes or smooth variations.

Direct Chip Attach commonly references a technique in which the chip is attached directly to the organic laminate. This paper deals with the general requirements for the printed circuit laminate on which a flip chip with controlled callapse chip connection (C 4 ) is directly attached. One of the key requirements is to reduce the coefficient of thermal expansion of the laminate. This paper also shows the calculated results for laminates made with fibers and resins whose material constants are realizable today, and concludes that it is possible to make low-expansion laminates suitable for direct chip attach.