Wave, ultrasonic

The most difficult, time-consuming, and frustrating aspect of protein purification is stabilization of the protein in an active form. This difficulty derives from the fact that the entire stabilization process must be reconsidered at each step of purification. For example, the first step of phosphoenolpyruvate carboxylase purification from peanut cotyledons 

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This result is valid when a < 1 this hypothesis is verified since ultrasonic waves are attenuated in materials. For separating two echoes, we detect the peaks and measure the delay between them. 

PARADISE (L.), Development of methods and a device of signal processing adapted to NDT by ultrasonic waves. Thesis of Doctor Engineer, INP Grenoble, 1983. 

The Investigation of Frequency Spectrum while Ultrasonic Wave Propogation in Anisotropic Media. 

Therefore, it is important for judging the performance and the safety of the product to understand the size of the defect and the position by the ultrasonic method quantitatively. And, the reliability of the product improves further by feeding back this ultrasonic wave information to the manufacturing process. 

Fig.6 shows the pulse shape at lOMHz in each point in Fig 5. As for measurement dB is constant because the material of the incidence of ultrasonic wave. The pulse amplitude has changed according to the thickness of the insert metal. Moreover, the direction of the first part of the pulse waveis different according to the material of the incidence of ultrasonic wave. 

Fig.7 shows the relation between the echo height F/B and the defect area s ratio Sr/So, when the ultrasonic wave is input from FCD500 side. This Sr/So is the ratio of the defect area Sr to the beam irradiational area So. Moreover, // X of (a) (b) (c) (d) are the value at the position where the echo height F/B is changed in Fig.5. And, the defect position of (i) (iv) in figure is shown the each position of Fig.3 respectively. Moreover, each curves are calculation values respectively, and this is described later. There has two case that F/T) of (a) (d) is changed by the defect position. The first case, F/B are increased as defect area s ratio Sr/So increases. The second case, F/B are increased after decrases as Sr/So increases. And defect area s ratio Sr/So to which F/B decreases is different according to the defect position...

Fig.9 shows the relation between the echo height F/B and the defect area s ratio Sr/So, when the ultrasonic wave is input from SUS304 side. As for each curves are similar to Fig.7. The tendency F/B are increased as Sr/So increases, or are increased after decrases as Sr/So increases by the defect position.

Here, Zi, Z2 and Zz are acoustic impedance of each materials as shown in Table 3. The order of Zi, Z2 and Z3 becomes Zi Z3 for the material on ultrasonic wave s incidence side. 

The reverse of the phase is shown that the bonding area rate became 80% or more, as the ultrasonic wave of incidence from the titanium side. 

And, the reliability of the product improves further by feeding back accurate ultrasonic wave information obtained here to the manufacturing process. 

Fig.4 shows the relation of the reflectional echo height F/B of the ultrasonic wave and... 

Fig.5 shows the relation of the echo height F/B and the retio of contact surface area Sa /So. The Sa is the contact surface area, and the So is the contact surface area of the V defectless. The F/B decreased with an increase in the Sa /So, as the ultrasonic wave from the incidence S45C side On the other hand, the F/B as the ultrasonic wave from the incidence Ti side has decreased with an increase in the Sa /So... 

The intial part of the pulse shapes are a direction of the minus as the incidence S45C side for the ultrasonic wave. 

Flere, Zi and Zi are the acoustic impedances of the material on a ultrasonic wave incidence side and confrontaion with the incidence side. 

The use of the surface ultrasonic waves seems to be convenient for these purposes. However, this method has not found wide practical application. Peculiarities of excitation, propagation and registration of surface waves created before these time great difficulties for their application in automatic systems of duality testing. It is connected with the fact that the surface waves are weakened by soil on the surface itself In addition, the methods of testing by the surface waves do not yield to automation due to the difficulties of creation of the acoustic contact. In particular, a flow of contact liquid out of the zone of an acoustic line, presence of immersion liquid, availability of chink interval leads to the adsorption and reflection of waves on tlie front meniscus of a contact layer. The liquid for the acoustic contact must be located only in the places of contact, otherwise the influence on the amplitude will be uncontrolled. This phenomenon distorts the results of testing procedure. 

The University developed a method of determination of the material residual strength, based on measurement of the change of phase velocity of ultrasonic waves, as well as an ultrasonic flaw detector-tomograph with multi-element transducers of the type of phased acoustic array. It enables control of the internal structure of materials and products of up to 300 mm thickness, with the resolution of up to 0.5 mm. In the same university, work on NDT is also carried out in the welding and electro-acoustic departments. 

Ultrasonic wave speed, Impact Echo and Spectral Analysis of Surface Waves... 

Ultrasonic wave speed, SASW and Impact Echo... 

Ultrasonic wave speed and Impact Echo High-Energy Radiography... 

Both ultrasonic and radiographic techniques have shown appHcations which ate useful in determining residual stresses (27,28,33,34). Ultrasonic techniques use the acoustoelastic effect where the ultrasonic wave velocity changes with stress. The x-ray diffraction (xrd) method uses Bragg s law of diffraction of crystallographic planes to experimentally determine the strain in a material. The result is used to calculate the stress. As of this writing, whereas xrd equipment has been developed to where the technique may be conveniently appHed in the field, convenient ultrasonic stress measurement equipment has not. This latter technique has shown an abiHty to differentiate between stress reHeved and nonstress reHeved welds in laboratory experiments. 

Fig. 7. Relations between elastic constants and ultrasonic wave velocities, (a) Young s modulus (b) shear modulus (c) Poisson s ratio and (d) bulk...

Liquid Level. The most widely used devices for measuring Hquid levels involve detecting the buoyant force on an object or the pressure differential created by the height of Hquid between two taps on the vessel. Consequently, care is required in locating the tap. Other less widely used techniques utilize concepts such as the attenuation of radiation changes in electrical properties, eg, capacitance and impedance and ultrasonic wave attenuation. 

Ultrasonic Properties. Vitreous sihca of high purity, such as the synthetic type, has an unusually low attenuation of high frequency ultrasonic waves. The loss, is a linear function of frequency, up to the 30—40 MHz region and can be expressed a.s A = Bf, where B = 0.26 dB-MHz/m for shear waves and 0.16 dB-MHz/m for compressional waves (168). 

The ultrasonic relaxation loss may involve a thermally activated stmctural relaxation associated with a shifting of bridging oxygen atoms between two equihbrium positions (169). The velocity, O, of ultrasonic waves in an infinite medium is given by the following equation, where M is the appropriate elastic modulus, and density, d, is 2.20 g/cm. ... 

The piezoelectric phenomena have been used to generate ultrasonic waves up to microwave frequencies using thin polyfvinylidene fluoride) transducers. In the audio range a new type of loudspeaker has been introduced using the transverse piezolectric effect on a mechanically biased membrane. This development has been of considerable interest to telephone engineers and scientists. 

Acrylamide readily undergoes polymerization by conventional free radical methods, ionizing radiation, ultrasonic waves, and ultraviolet radiation. The base-cata-lized hydrogen transfer polymerization of acrylamide yields poly-/3-alanine (Nylon 3) a water insoluble polymer that is soluble in certain hot organics. All current industrial production is believed to be by free radical polymerization. 

Tokuoka T., Iwashitnizu Yu., Acoustical birefringence of ultrasonic waves in deformed isotropic elastic materials, Int. J. Solids Structures, 4 (1968), 383—389. 

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