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This study evaluated energy transfer and efficiency in power ultrasound systems applied to processing of Chlorella vulgaris. Power transfer to a series of system combinations was characterized via ...

The objective of this study is to evaluate the ultrasound test to estimate the depth of cracks in concrete, using a mathematical model published in the literature, and to verify this depth with more accurate results. Four concrete test specimens were molded for each proposed crack depth (5 cm, 10 cm, and 15 cm), simulated using zinc plates, placed during molding and removed before concrete hardening. The results show that the test is sensitive enough to detect the presence of the cracks in the concrete. The mathematical model used allowed for an estimation of the depths of most cracks, but the results are scattered and have a high margin of error for the depths of 5 cm and 15 cm. The cracks of 10-cm depth produced better results.

The issue of samples shape and size effect on the destructive strength of concrete returns from time to time because the compliance of conversion factors proposed by various authors is not satisfactory. Modern drilling equipment encourages to take samples from the structure and to conduct tests of concrete compressive strength based on the destruction of cylinders. This paper presents the ultrasound test methodology for determination of ‘d’ conversion factor from samples obtained, e.g., from structure for strength determined on other samples. First, the velocities of longitudinal ultrasound waves were reduced to a fixed base because samples of various sizes from O4 to O32 cm were tested. Regression curves for the tested samples were determined, separately for each size. Based on these, for various ultrasound velocities and various sizes of samples strengths and relations between strengths was calculated. Formulas were given, which allow to convert the strength from sample of any diameter to the different one. The example of ultrasound testing method for the evaluation of mortar strength in joints between bricks was also presented.

Aboonajmi M., Akram A., Nishizu T., Kondo N., Setarehdan S.K., Rajabipour A., 2010. An ultrasound based technique for the determination of poultry egg quality . Res. Agr. Eng., 56: 26–32. The present study investigates the possibility of the non-destructive prediction of the main quality indices of commercial eggs by calculating the ultrasound phase velocity within the egg material. The phase velocity of the ultrasound signal in the egg material was determined by analysing the recorded ultrasound signals using the Fast Fourier Transform. Three hundred commercial eggs (Boris Brown, 33 weeks age) from the first day of egg laying were purchased from a farm and divided in two groups. The first group was kept at the room temperature (22–25°C) and the second group was kept in a refrigerator (5°C). Every week, 25 eggs from both the room and the refrigerator were first submitted to the non-destructive ultrasound test at weekly basis at the room temperature. Immediately after testing, the air cell, the thick albumen heights, the Haugh unit and the yolk index of the eggs were also determined destructively for the comparison purposes. The results were analysed to find any possible correlation between the computed ultrasonic phase velocity and the destructive parameters, during a storage period of five weeks. The tests were carried out using an ultrasound beam with a frequency of 150 kHz with a sampling rate of 2.5 Gs/S on the eggs under a controlled temperature situ ation. Significant differences between the means of the destructive analysis on different days of the eggs storage were found using ANOVA. The results showed that the phase velocity significantly differs between the eggs stored at the room temperature and those stored in the refrigerator. It was found that the phase velocity decreased as the storage time of the eggs increased in three consecutive weeks.

A test for evaluating oilfield corrosion inhibitors using ultrasound has been developed recently. This paper describes experiments that have been undertaken to try and determine some of th...

The article presents the results of the investigation of universal calibration dependences used in testing of the concrete strength by shear, rebound and ultrasound test methods. Many of the instruments currently used do not provide the required measurement accuracy, especially when using universal calibration dependences. The introduction of new more sophisticated instruments for nondestructive testing of concrete strength requires an assessment of their accuracy, taking into account the composition of concrete and other parameters. The shear test method, called “direct”, does not provide the required accuracy of measurements, and the use of this method for the calibration of sclerometers and ultrasonic devices is unacceptable.The aim of the research is to clarify the dependences, taking into account the data on concrete composition, parameters of materials used, and the age of concrete. The studies will allow you to set the values of the coefficients to be used in the generalized calibration curve, with considering the concrete information obtained at a particular construction site (where concrete strength is tested).

This study demonstrated the feasibility of applying an ultrasound test to evaluate the ability of a powder to interact with a solvent and thus to predict the reconstitution behaviour of powders. The ultrasound attenuation was monitored and a corresponding relaxation time was calculated. Analysis of the ultrasound signal and images obtained by a granulomorphometer in the course of dispersion showed that the time required by the ultrasound attenuation parameter to relax is strongly associated with the time required by the solvent to penetrate primary particles. It was also shown that this step is of crucial importance in the dissolution mechanism as it precedes the fragmentation phase, identified as a limiting step. Classification of dairy powders according to their relaxation times (ultrasound test) and rehydration times (rehydration test, calculated with Static Light Scattering) was in good agreement for the range of milk powders investigated. Industrial relevance Spray drying is commonly used to produce dairy powders in the food industry. Although the rehydration of these powders can be very slow, few analytic methods are available to evaluate the dissolvability of a dairy powder; consequently, there is a current lack of guidelines in order to tune spray dryer operating parameters for improving instant properties. The objective of this study is to present a new analytical method based on ultrasound test to evaluate powder ability to reconstitute. A probe was immerged in the liquid and the transmitted signal was analysed during the course of rehydration. The acoustic test was demonstrated to be effective in tracking solvent interactions, making it possible to assess the ability of a solvent to bind with the primary particle, and thus revealing it to be a powerful tool to evaluate the reconstitution ability of dairy powder quickly with low material costs. Of course the scope of this tool is broader than the sole food sector and encompasses all applications requiring a reconstitution step in a solvent.

During the manufacture of silicoferrochromium, fume is collected in electrostatic filters. The main reason is to prevent environmental pollution. A review of the literature shows that researchers have been conducted in order to investigate the economical usability of this fume for industrial purposes. Silicoferrochromium fume containing 85.5% SiO[sub 2] was investigated to determine whether it could be used as an admixture in concrete to increase its strength. The fume was added at the dosage rates of 0--5% by weight of cement, and a number of test specimens were prepared from this concrete mixture. The unit weight, ultrasound test, hardness, compressive strength of the concrete specimens were determined. The initial and final time of setting values of the mortar specimens were measured. The test results indicated that the properties of the concrete changed considerably with the addition of the silicoferrochromium fume. The compressive strength of the concrete was observed to be maximum at 2% fume content.