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.

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.

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.

An incarcerated epigastric hernia (localized in linea alba) is a very rare observation. Here, we present a case of a 66-year-old white male who was admitted to the emergency department due to vomiting and epigastric pain. On physical examination, the only observed abnormality was a painless soft epigastric tumor located in the upper midline, measuring about 12 cm in diameter. The patient claimed that he had the tumor for more than 30 years and it never changed in diameter nor caused him any discomfort. A lipoma was initially suspected. However, an ultrasound of the abdomen revealed an incarcerated stomach, trapped due to the defect in the epigastric abdominal wall. The patient was sent for surgery and the presence of an incarcerated epigastric hernia of the linea alba, which contained the anterior wall of the stomach was confirmed. The presented case confirms that the use of ultrasonography may be an effective method to recognize unusual types of hernias, and that ultrasonography should be routinely used in emergency departments.

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.

Recently, significant progress has been made in experimental studies on the flow of wet steam, measuring techniques based on recording the phenomenon of extinction of light and ultrasound have been elaborated or improved. The basic value experimentally determined in the final stage was the content of the liquid phase defined as the wetness fraction. The methodology of tests and experimental investigations was presented, as well as the applied and developed measurement systems. Next, some developed designs of new ultrasonic and light extinction measuring probe and their modifications are described. The article presents also some examples of applications of the developed measurement techniques in application to experimental research conducted on wet steam. Examples of comparison between experimental and numerical tests for the extinction method are also provided.

One of the least expensive and safest diagnostic modalities routinely used is ultrasound imaging. An attractive development in this field is a two-dimensional (2D) matrix probe with three-dimensional (3D) imaging. The main problems to implement this probe come from a large number of elements they need to use. When the number of elements is reduced the side lobes arising from the transducer change along with the grating lobes that are linked to the periodic disposition of the elements. The grating lobes are reduced by placing the elements without any consideration of the grid. In this study, the Binary Bat Algorithm (BBA) is used to optimize the number of active elements in order to lower the side lobe level. The results are compared to other optimization methods to validate the proposed algorithm.

The article discusses the issues of accounting the direction pattern of parametric antenna array the propagation of sound over the Earth’s surface. As a radiator, a parametric antenna array is used. A description is given of measuring equipment and experimental research methods. The Delaney-Bezley model was used as a model of the Earth’s surface impedance. The research results showed the importance of accounting the direction pattern of parametric antenna array in predicting the sound pressure level of a propagating acoustic signal over the Earth’s surface. On the example of a difference signal with a frequency of 2 kHz, the calculation of the sound pressure level on a 100-meter path with the influence of the Earth’s surface is shown. The results obtained showed a good agreement between the theoretical calculation and experimental data.

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.