Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 5
items per page: 25 50 75
Sort by:

Abstract

The article describes the method of controlling the recovered grade based on measuring the intensity of volume ultrasonic oscillations and Lamb waves covering a fixed distance through the test medium and on a metal plate contacting the test medium at various time points of deliberate motion of ground materials. The authors suggest a method of determining density of ground ore particles in the pulp periodically after isolating the pulp flow in the vertical part of the measuring vessel based on measuring attenuation change values in Lamb waves covering a fixed distance on a plate contacting the medium under study and high frequency volume ultrasonic oscillations that have come through it within a certain time period. There are given dependencies of amplitudes of measuring channels based on volume ultrasonic oscillations and surface Lamb waves, size distribution according to solid phase pulp particles for various types of ores under study, a set of curves for determining the recovered grade with regard to various types of ores under study.
Go to article

Abstract

The aim of the study was to determine the impact of various methods of oil mixing with wastewater on properties of synthetic municipal wastewater containing edible oil (SMW+0.02% m/v rapeseed oil). The study was carried out in 3L glass, cylindrical reactors to which SMW+0.02% were introduced. Various methods of its mixing with water were applied: mechanical mixing (SMW+0.02%+mixing) and sonication (SMW+0.02%+ultrasounds). The wastewater was sonicated at 35 kHz for 30 min. The constant temperature conditions were maintained during the experiment for each mixing method (15°C, 20°C and 30°C). The analysis of parameters (pH, COD, BOD5 and long chain free fatty acids concentration) of raw wastewater and after 2, 4, 6, 24, 48 and 72 hours of inoculation was performed to determine the effect of mixing method. The most signifi cant changes in wastewater chemical parameters after the introduction of the oil were observed in the case of COD. For SMW+0.02%+ mixing a slow increase in COD within 24 hours of the process was observed. In the case of SMW+0.02%+ultrasounds the increase and the decrease of COD value were observed in reference to the initial value. The changes in acids concentrations observed in reactors with SMW+0.02%+ultrasounds were referred to the ones observed in reactors with SMW+0.02%+mixing but changes were more intense in the fi rst reactor. The use of ultrasounds in pre-treatment of wastewater resulted in the intense appearance of palmitic acid for 6 hours. Regardless of the emulsion formation method (mixing or ultrasounds), the concentration of oleic acid and linoleic acid was reduced. The biggest changes in free fatty acids concentration were observed for palmitic, oleic and linoleic acids after 24 hours.
Go to article

Abstract

The possibility of acoustic wave propagation in optical waveguides creates new prospects for simultaneous transmission of laser beams and ultrasonic waves. Combined laser-ultrasonic technology could be useful in e.g. surgical treatment. The article presents the results of experimental studies of transmission of ultrasonic wave in optical fibres, the core of which is doped by 7.5% of TiO2, using a sandwich-type transducer. It also presents amplitude characteristics of an ultrasonic signal propagated in the optical fibre. Authors studied the effect which the length of the fibre has on the achieved output signal amplitudes. They presented the relation of the output signal amplitude from a capacitive sensor to the power applied to the sandwich-type transducer. The obtained results were compared with the results produced when using an optical fibre with a core doped by 3% of GeO2, in order to select optical fibre suitable for simultaneous transmission of ultrasonic waves and laser rays.
Go to article

Abstract

The work presents the results of experimental study on the possibilities of determining the source of an ultrasonic signal in two-dimensional space (distance, horizontal angle). During the research the team used a self-constructed linear array of MEMS microphones. Knowledge in the field of sonar systems was utilized to analyse and design a location system based on a microphone array. Using the above mentioned transducers and broadband ultrasound sources allows a quantitative comparison of estimation of the location of an ultrasonic wave source with the use of broadband modulated signals (modelled on bats' echolocation signals) to be performed. During the laboratory research the team used various signal processing algorithms, which made it possible to select an optimal processing strategy, where the sending signal is known.
Go to article

Abstract

This paper presents an analysis of use of ultrasonic standing wave in cell separation from bodily fluids based on the example of erythrocyte separation from plasma. It describes movement of red blood cells in plasma under the influence of the acoustic field (whose forces result from interaction of red blood cells with plasma as the vibrating medium) and under the influence of resistance forces in Stokes’ and Oseen’s approximation. The general properties of solutions of the motion equation are given. The solutions for the parameters of the ultrasonic wave and blood cells which are interesting in terms of practical applications in medical diagnostics are discussed. Time constants of the cell transportation to the regions of stable equilibrium in the field of ultrasonic standing wave are estimated. The formulas which determine the time needed to obtain the assumed concentration increase in plasma in nodes and/or anti-nodes of the standing wave are derived.
Go to article

This page uses 'cookies'. Learn more