Mobile devices can be protected by a variety of information flow control systems. These systems can prevent Trojans from leaking secrets over network connections. As mobile devices become more secure, attackers will begin to use unconventional methods for exfiltrating data. We propose two sound-based covert channels, ultrasonic and isolated sound. Speakers on mobile devices can produce frequenc...

Ultrasonic acoustic emissions (AE) in the frequency range of 0.1 to 1 megahertz appear to originate in the sapwood of Thuja occidentalis L. The AE are vibrations of an impulsive nature. The vibrations can be transduced to a voltage waveform and amplified. The vibrations of each AE event begin at a large amplitude which decays over 20 to 100 microseconds. Strong circumstantial evidence indicates...

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...

Violation of reparative regeneration of bone tissue in treatment of open fractures is an urgent problem [1,2]. The frequency of unsatisfactory results of the treatment of these fractures remains high (30%) [3]. The main factors of bone regeneration disorders in conditions of open fractures are following: damage to soft tissue, soft tissue tropism violation, violation of bone trophic and infecti...

A multi-DOF ultrasonic motor developed by the authors is capable of generating multi-DOF rotation of a spherical rotor using three orthogonal natural vibrations of a bar-shaped stator. The ultrasonic motor is suitable for making small, light weight and simple multi-DOF motion unit. In the present paper, a control methodology for the multi-DOF ultrasonic motor is proposed and a motion control te...

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...