Kinetics of epoxy resin optical characteristics during ultrasonic processing

In this paper, the ultrasonic processing of composite based on epoxy resin ED-20 filled by nanoparticle silicon–containing additives PDMS-5 and HDK during its preparation is studied. Changes in optical transmittance spectra of organosilicon gel (PDMS-5+HDK) and of composite ED-20+L-20+(PDMS-5+HDK) are reported. The observed optical transmission changes were modeled from the experimental results. New phenomenological model describing the kinetics of a change in transmittance with ultrasonic processing time of composite is proposed. The nonlinear differential equation of the process is formulated and solved. The solution of equation applies to description of the experimental data of monitoring of transmittance of composite ED-20+L-20+(PDMS-5+HDK) during ultrasonic processing. The nonlinear functions characterized by three plateaus are proposed to describe the experimental data of monitoring of optical properties of organosilicon gel (PDMS-5+HDK) during ultrasonic processing.

Effects of fermentation on the degree of breaking up of bone particles in meat and bone paste from cattle bones

Bone processing is an urgent task of rational use of meat industry waste. Disposal of cattle bones can be carried out by different methods. Various methods are used for processing bone raw materials, such as mechanical processing, chemical hydrolysis, ultrasonic processing, etc. Processed meat and bone raw materials in meat and bone paste are chemically exposed to ascorbic acid (0.05 M, 1 h, 25 ° C) and pepsin (pH 2.0, t=10...40 ° C, τ=1...8 h). This allows you to reduce the mass of bone particles in meat and bone paste by 70%. Meat and bone paste subjected to enzyme processing can be used in the technology of meat products.

Ultrasonic Processing of Si and SiGe for Photovoltaic Applications

The usage of power ultrasound for sonochemical processing of Si wafers and thin layers of amorphous Si and SiGe alloys is described. Over the last decade different industries have become increasingly drawn to sonochemistry because it provides a green and clean alternative to conventional technologies, particular in the areas of processing of silicon-based materials for photovoltaic applications. Two techniques related to ultrasonic cleaning of Si wafers and sonochemical modification of Si, SiGe and a-Si/SiGe surfaces in hydrocarbon solutions of chloroform (CHCl3) and dichloromethane (CH2Cl2) are discussed. The occurrence of cavitation and bubble implosion is an indispensable prerequisite for ultrasonic cleaning and surface processing as it is known today. The use of higher ultrasonic frequencies to expand the range of ultrasonic cleaning and processing capabilities is emphasized. Although exact mechanisms of an improved photoelectric behavior of Si-based structures subjected to power ultrasound are not yet clarified in many cases, the likely scenarios behind the observed photovoltaic performances of Si, SiGe and a-Si/SiGe surfaces are proposed to involve the surface chemistry of oxygen and hydrogen molecules as well hydrocarbon chains.

Comparison of Conventional and Hybrid Ultrasonic Milling in the Processing of Improved Steel

The combination of conventional milling and ultrasonic processing, more precisely ultrasonic vibrations, belongs to the newer types of hybrid processing. The realization of vibration sources as well as parameters that are variable in the realization of this process capture the attention of readers. In this paper, in addition to the application and possibility of installing different types of ultrasonically supported milling, the emphasis is given in the field of the surface quality. Namely, the application of ultrasonic vibrations in the processing of steel for improvement, which are characterized by higher hardness and toughness, and as such are a challenge for finding the most favorable processing. The quality of the processed surface as a function of the mean arithmetic roughness and the mean height of the unevenness measured in 10 points obtained in the classical conventional milling and the new hybrid process are presented.