Current study was designed to investigate the protective effects of royal jelly on Flunixin me- glumine (FM)-induced spermiotoxicity related to sperm concentration, abnormal spermatozoa count and histopathological changes in mice testis. The subjects were divided into five groups according to FM and/or royal jelly intake: Control group; group 1, FM alone (25 mg/kg, im); group 2, combination of FM (25 mg/kg, im) and royal jelly (200 mg/kg, oral); group 3, FM alone (50 mg/kg, im); and group 4, combination of FM (50 mg/kg, im) and royal jelly (200 mg/kg, oral). The animals were fed once daily for 15 days and they were sacrificed last day. Epididymal sperm concentration and abnormal spermatozoa count were noted. Testicular histological findings were evaluated. On purpose, organization of each animal was graded according to Johnsen’s scoring to assess the spermatogenesis relying on seminiferous tubule cross-section scores. Comparing to controls, FM administration caused a decrease in sperm concentration (p<0.05), an increase in total abnormal spermatozoa rates (p<0.05) and more degenerative changes in testes in mice.
Royal jelly supplementation ameliorated both sperm concentration and abnormal spermato- zoa (p<0.05) comparing to the control group. In conclusion, we suggested that royal jelly might have protective effects in the FM-induced reductions in epididymal sperm concentration and in- crease in abnormal spermatozoa rate.
In this study T6 heat treated 6063 aluminum alloys were used as substrate material. In order to form a bond between the substrate and the
main coating, all samples were coated with Ni-Cr-Al powders. 8 wt% Yttria Stabilized Zirconia powders (YSZ) were coated with plasma
spray technique. Thickness of YSZ was 150 m and bond coating was 36 m. XRD and SEM-EDS analyses were performed to characterize
the coating layers. These YSZ coated and uncoated samples were subjected to wear testing under different spindle speed, loading and
working distance. Wear test results were compared with the kinetic friction coefficients and weight loss values. Wear marks on YSZ
coated and uncoated samples were investigated by SEM analysis. By coating with plasma spray technique, the wear resistance of Al alloys
was increased without changing the friction coefficient. It was found that spindle speed had significant effect over the wear properties than
the load applied. By YSZ coating, wear properties were increased 10 times.
AISI 52100 bearing steels are commonly used in applications requiring high hardness and abrasion resistance. The bearing steels are
working under dynamic loads in service conditions and their toughness properties become important. In order to provide the desired
mechanical properties, various heat treatments (austenizing, quenching and tempering) are usually applied. In this study, AISI 52100
bearing steel samples were austenized at 900°C for ½ h and water quenched to room temperature. Then tempering was carried out at
795°C, 400°C and 200°C for ½ h. In order to investigate the effect of heat treatment conditions on wear behavior, dry friction tests were
performed according to ASTM G99-05 Standard with a ‘ball-on-disk’ type tribometer. The samples were tested against steel and ceramic
counterparts using the parameters of 100 m distance and 30 N load and 0.063 m/s rotational speed. After wear test, the surface
characterization was carried out using microscopy. Wear loss values were calculated using a novel optical method on both flat and
counterpart specimens.
In this study, an artificial neural network application was performed to tell if 18 plates of the same material in different shapes and sizes were cracked or not. The cracks in the cracked plates were of different depth and sizes and were non-identical deformations. This ANN model was developed to detect whether the plates under test are cracked or not, when four plates have been selected randomly from among a total of 18 ones. The ANN model used in the study is a model uniquely tailored for this study, but it can be applied to all systems by changing the weight values and without changing the architecture of the model. The developed model was tested using experimental data conducted with 18 plates and the results obtained mainly correspond to this particular case. But the algorithm can be easily generalized for an arbitrary number of items.
The formation of oxide film on the surface of aluminium melts, i.e. bifilms, are known to be detrimental when they are incorporated into
the cast part. These defects causes premature fractures under stress, or aid porosity formation. In this work, Al-12 Si alloy was used to cast
a step mould under two conditions: as-received and degassed. In addition, 10 ppi filters were used in the mould in order to prevent bifilm
intrusion into the cast part. Reduced pressure test samples were collected for bifilm index measurements. Samples were machined into
standard bars for tensile testing. It was found that there was a good agreement with the bifilm index and mechanical properties.