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.
This study was carried out to evaluate the potential effects of 90 days-long dietary supple- mentation of probiotic and yeast culture on immunity condition of lambs. Fifteen Rahmani growing male lambs (about 5 months old and 23.21±2.75 kg body weight) were randomly allo- cated to three equal groups consisting of 5 animals each. The animals in the first group, served as a control (group C), were fed a basal diet without any supplementation. The lambs in the second and third group were fed the basal diet supplemented with probiotic (group Y) or yeast culture (group YC), respectively. The probiotic consisted of live yeast (Saccharomyces cerevisae) alone, while the yeast culture was composed of Saccharomyces cerevisiae and the media on which it was grown. In group Y and YC, each lamb was supplemented daily with 0.5 g and 7.0 g of live yeast and yeast culture, respectively. Blood samples were collected before feeding the supplements and then every 15 days until the day 90th. Total and differential leucocytic counts, total protein, albumin, IgA, IgG and IgM levels were measured in blood. There were insignificant (p>0.05) variations in the levels of total and differential leucocytic counts and total protein among the groups throughout the experiment. However, significant differences (p<0.05) were found in globulin, IgA, IgG and IgM in both (Y) and (YC) groups, but the effect of yeast culture seems to be better than that of the probiotic. In conclusions, the obtained results indicate that the tested probiotic and yeast culture improve the immunological status of lambs.
Early castration of male small ruminants is regarded as a risk factor for urolithiasis, although the underlying correlations are still unclear. One possible reason is a deferred development of the penis and the urethra after castration. Therefore, we examined the penis and urethra of castrated and intact lambs by ultrasonography to determine the correlation between urethral area and pe- nile cross-sectional area. Ultrasonography was performed in 6-month-old Lacaune crossbred lambs (early castrated, late castrated, and intact; each group, n = 11). Sectional images at 5 loca- tions (glans penis, penile urethra, distal and proximal sigmoid flexure, and ischial arch) were ob- tained to determine the urethral and penile diameters. Urethral and penile cross-sectional areas were calculated. Grey-scale analysis of ultrasound images was performed to evaluate possible differences in the penile texture between the groups. Correlation analyses between both cross-sectional areas showed a significant general correlation for location 2 in all lambs (R = 0.52; P = 0.003), for location 3 in late-castrated lambs, and for location 5 in early-castrated lambs. Statistically significant correlations between the penile and the urethral area of castrated and intact lambs were not evident. Therefore, measurement of the penile cross-sectional area alone does not allow for accurate estimation of urethral size. Statistically significant differences con- cerning the grey-scale analysis between the groups were also not detectable. Thus, simplification of the formerly presented ultrasonographic examination of the urethra is not recommended. In animals at a risk of obstructive urolithiasis, complete urethral examina- tion is essential.
The use of lactoferrin (LF) and/or lactobacillus sp. (LB) to improve animal health and production has increased recently. However, information regarding the immune-modulatory role of LB supplementations either alone or in combination with LF in sheep remains unclear. Therefore, the present study was designed to evaluate the immune modulating properties and the antioxidant activity of supplementing commercially available LF and/or LB in healthy lambs. For this reason, twenty-four apparently healthy Ossimi lambs were used. After three weeks of acclimatization, the lambs were randomly allocated to four equal-sized groups and assigned to receive one of the following supplements: LB at a dose of ~ 1 g active ingredient/head (group 1), LF at a dose rate of 0.5 gm /head (group 2), a combination of both treatments using the same dosing regimens (group 3), and (group 4) received only 10 mL of isotonic saline and was considered as a control group. All supplements were given orally twice daily for 30 consecutive days. Blood samples were collected from each lamb before starting the experiment (T0) and two weeks (T15), and four weeks (T30) after giving supplements for hematological examinations, serum biochemical analyses, and RT-PCR assays. Our findings demonstrated that lambs receiving LB showed statistically significant (P<0.05) higher values of total leucocytes, lymphocytes and lysozyme activity than those receiving LF. In contrast, lambs that received LF had significantly (P< 0.05) higher values of serum catalase, nitric oxide and GSH with a significantly lower MDA level compared with those supplemented with LB. A combination of LF and LB supplementation elicited maximal up-regulation of Tollip, TLR4, IL-5, and IL-6 gene expression compared with other groups. The results suggest that bovine LF and or LB could be used as useful nutritional supplements to support the immune system in healthy lambs.
The knowledge of the load in prestressed bolted connections is essential for the proper operation and safety of engineering structures. Recently, bolted joints have become an area of intensive research associated with non-destructive diagnostics, in particular in the context of wave propagation techniques. In this paper, a novel procedure of bolt load estimation based on the energy of Lamb wave signals was proposed. Experimental tests were performed on a single lap joint of two steel plates. Ultrasonic waves were excited and registered by means of piezoelectric transducers, while precise measurement of the bolt load was obtained by means of using the force washer transducer. Experimental tests were supported by the finite element method analysis based on Schoenberg’s concept. The results showed that the relationship between the bolt load and signal energy was strongly nonlinear and it depended on the location of acquisition points.