ultrasonic assisted drilling (usd) is new technique to drill difficult to machine materials. in this method, tool or workpiece vibrates with amplitude of few microns in addition to conventional drill bite rotation. in this experimental research, the bone was drilled both conventionally and using uad, then the thrust was measured in two methods at feed rates of 50, 75 and 125 mm/s and 500, 710 a...

Microwave-assisted and ultrasound-assisted extraction assays were used to isolate total flavonoids (TF) from Osmanthus fragrans flowers. The effects of the solid-liquid ratio, ethanol concentration, microwave power, microwave extraction time, ultrasonic power and ultrasonic extraction time on the yield of TF were studied. A sequential combination of microwave- and ultrasound-assisted extraction...

The measurement of acoustic nonlinear response is known as a promising technique to characterize material micro-damages. In this paper, nonlinear ultrasonic approach is used to characterize the evolution of fatigue induced micro-cracks in polymer bonded explosives. The variations of acoustic nonlinearity with respect to fatigue cycles in the specimens are obtained in this investigation. The pre...

The transesterification reaction of present study was assisted by ultrasonic mixing and microwave irradiation. Central composite design (CCD) was employed to optimize the transesterification reaction conditions of biodiesel production from soybean oil. A mathematical model predicted that the theoretical conversion rate of soybean oil of 102.19% could be obtained under the following reaction con...

The objective of this work is to provide a theoretical basis for preparing peanut antioxidant hydrolysate in order to improve its antioxidant activities. Therefore, response surface methodology (RSM) based on the Box-Behnken design was used to optimize ultrasonic-assisted enzymolysis for the purpose of preparing peanut antioxidant hydrolysate. Results indicated that the DPPH free radical scaven...

Double-side replication of polymer substrates is beneficial to the design and the fabrication of 3-demensional devices. The ultrasonic embossing method is a promising, high efficiency and low cost replication method for thermoplastic substrates. It is convenient to apply silicon molds in ultrasonic embossing, because microstructures can be easily fabricated on silicon wafers with etching techni...

tio2 /fe3o4 nanocomposites with various tio2:fe3o4 ratios were synthesized by an ultrasonic-assisted deposition-precipitation method and their uv-light decolorization of congo dye and magnetic separation were investigated. the nanocomposite samples were characterized by scanning electron microscopy (sem), powder x-ray diffraction (xrd), surface area analayzer (bet) and fourier transform infrare...

size reduction of high energy materials such as 1, 3, 5, 7-tetranitro- 1, 3, 5, 7-tetraaza cyclooctane (hmx) has considerable influences on improving their explosive characteristics. in this study, nanosized hmx par­ticles were produced using ultrasonically reprecipitation method by applying water as a safe and accessible antisolvent instead of unsafe conventional methods. sem photographs revea...

PURPOSE Palpation is used most commonly to assess tissue stiffness despite its well-known deficiencies. As an improvement, a mechanical technique known as ultrasonic indentation has been proposed. The purpose of this study was to compare the accuracy of 3 ultrasonic indentation techniques in quantifying bone displacement in a specially constructed tissue simulator. METHODS Three ultrasonic in...