Ultrasonic vibrator

Kolosov O and Yamanaka K 1993 Nonlinear detection of ultrasonic vibrations in an atomic force microscope Japan. J. Appl. Phys. 32 LI 095... 

Ultrasonic Microhardness. A new microhardness test using ultrasonic vibrations has been developed and offers some advantages over conventional microhardness tests that rely on physical measurement of the remaining indentation size (6). The ultrasonic method uses the DPH diamond indenter under a constant load of 7.8 N (800 gf) or less. The hardness number is derived from a comparison of the natural frequency of the diamond indenter when free or loaded. Knowledge of the modulus of elasticity of the material under test and a smooth surface finish is required. The technique is fast and direct-reading, making it useful for production testing of similarly shaped parts. 

These reversible reactions are cataly2ed by bases or acids, such as 2iac chloride and aluminum isopropoxide, or by anion-exchange resias. Ultrasonic vibrations improve the reaction rate and yield. Reaction of aromatic aldehydes or ketones with nitroparaffins yields either the nitro alcohol or the nitro olefin, depending on the catalyst. Conjugated unsaturated aldehydes or ketones and nitroparaffins (Michael addition) yield nitro-substituted carbonyl compounds rather than nitro alcohols. Condensation with keto esters gives the substituted nitro alcohols (37) keto aldehydes react preferentially at the aldehyde function. 

Oscillators (82) and ultrasonic vibrations (83) have also been used to lower 5. 

Fig. 5.9a-i Air-water two-phase flow patterns in a 100 pm i.d. clean quartz tube treated with ultrasonic vibration in distilled water, in ethanol and in dilute hydrochloride acid solution. Reprinted from Serizawa et al. (2002) with permission... 

Soil Extract using ultrasonic vibrations GC/FID/FPD/MS No data No data Sawyer et al. 1992... 

Ultrasonic cavitation (using high-energy ultrasonic vibrations to generate high temperatures and pressures). 

Namgoong E, Chun JS (1984) The effect of ultrasonic vibration on hard chromium plating in a modified self-regulating high speed bath. Thin Solid Films 120 153-159... 

This reaction has been induced in several ways, but one novel procedure involves the action of ultrasound on a suspension of the two solid reactants in dodecane. The ultrasonic vibrations create cavities in the liquid that implode, driving particles of the solid together at high velocity. Under these conditions, the solids react in much the same way as if they were heated, but in cases where an unstable product is formed, it is not thermally decomposed. 

Many cells, especially bacteria, yeast, etc., require very drastic measures to disrupt them and various cell disintegrators are available for this purpose. Ultrasonic vibrations cause the formation of minute bubbles, a phenomenon known as cavitation, which is caused by the extreme variations in pressure generated by the sound waves, although the generation of heat may cause problems unless the samples are cooled frequently during the treatment. An additional... 

Tool attached to horn which conducts ultrasonic vibrations to workpiece... 

The ultrasonic vibration of 20 kHz applies an intermittent force to the material to be cut and generates a crack (cut) at the tip, controlling its propagation or growth thereby minimising the stress on the bulk material. 

In the 1950 s an investigation into the effect of ultrasonic vibrations on the mechanical properties of metals showed that superimposing an alternating stress on a workpiece greatly affected the process rate and considerably reduced the force necessary for work-piece deformation [20]. 

One of the consequences of this is that improvements in the cold drawing of metal tubing can be achieved when the die to be used is subjected to radial ultrasonic vibrations. There are several advantages obtained from drawing round products through a die ultrasonically vibrating in a radial mode, these include ... 

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