Introduction Lameness originating from the distal limb is common in sport horses and can vary depending on the dynamics of movement and the surface, with differences in shoeing exacerbating this ...variability. Driving horses work primarily on hard surfaces (pavement), whereas dressage horses work primarily on soft surfaces (riding arenas with sand). Driving horses are traditionally shod with small fixed studs made of hard metal, which are attached to the horseshoe at 4 points, while dressage horses are shod with a simple horseshoe. We investigated the hypothesis that there is a difference in the pathological radiographic findings of the distal limbs between driving and dressage horses. The variability in the stable management and training program was minimized by including horses from the same farm. Methods Twenty horses in a driving training program and 20 horses in a dressage program were included in the study. Radiographs of the both front feet were obtained and quantitatively evaluated for radiographic changes by three surgery/diagnostic imaging specialists. Interrater reliability was measured, and multivariate analysis was performed to compare differences in pathological radiographic findings of the distal limbs between the two groups. Results Kendal’s concordance coefficient indicated an agreement among raters (Kw ≠ 0) for all observations. Radiographic signs of degenerative joint disease of the distal interphalangeal joint were more common in the group of driving horses compared to dressage horses. Conclusion Our hypothesis was confirmed, as there were significant pathological differences between groups in distal articular margin of middle phalanx, joint space narrowing, and irregular joint surface of the middle phalanx.
In mechanical engineering, there is a class of parts with a wheel pairs or with a curved working surface, such parts include wheel pairs of rail vehicles. During the operation of locomotives of main ...and industrial railway transport, it is periodically necessary to restore the worn-out profile of the wheels without dismantling the wheel pairs. The article analyzes and notes the need to improve the process of repairing of locomotive wheel pairs in. The efficiency and reliability of special shaped cutters and rail vehicles depends on the quality and accuracy of the repair process. The methodology is described for studying the dynamics of cutting processes on special machines KZh20, it is necessary to take into account not only the cutting forces, but also the structural properties of shaped cutters (tools), as well as the workpiece (working surface of wheelsets). Based on the mathematical model of process of restoration of working profile of tools of wheel-cutting machines KZh20 zones of stable parameters of milling process dynamics can be determined in conditions of simultaneous presence of two non-rigid elements (machined part and special shaped cutter). The method for determination of torque value taking into account transmission ratio of mechanical transmission is proposed.
The results of a study of the noise generating mechanism during the application of disk brakes on rolling stock are presented. It is shown that one of the main sources of noise generation is the ...deformation of the microgeometry of the surface layer and its elastic recovery, which occurs under the influence of the interaction of the working elements of the disk brake. The influence of the ratio of the working areas of the friction elements that model the brake pad and brake disc on the noise intensity during their interaction is estimated. A design and technical method is proposed for reducing the noise level of a disk brake during braking, which consists of increasing the ratio between the working areas of the brake pad and brake disc.
Screw turns are known to be deformed as a result of the contact pliability of the nut and screw surfaces. The load distribution over the turns is investigated when fine thread is employed, when ...compression nuts are replaced by tension–compression and tension nuts, when the roughness of the working surfaces is increased, and when the load on the screw is increased.
With allowance made for thermoelasticity of working surfaces and inertia forces on the lubricant coat, a hydrodynamic problem is solved for the noncontacting face seals with microgrooves in the ...high-speed rotors of FV engines. Also shown are the initiation of surface waviness in the zone of lubricant coat fracture and the influence of its amplitude upon the seal characteristics.
Odor pollutants from a landfill can have serious impacts on the surrounding environment and nearby residents. Moreover, the variety and complexity of volatile organic compounds (VOCs) along with the ...landfill odor makes sampling and identifying compounds challenging. In this study, the authors monitored municipal solid waste (MSW)-related areas, sludge-related areas and waste coverage with the most malodorous compounds. In terms of all 120 VOCs, 67 malodorous VOCs with significant variations were categorized into six classes of compounds under all test conditions. Among the concentration characteristics, Site B concentrations were the highest. For the odor index (OI), the OI values of Site B were higher than those on other sites. The organic sulfides, organic acids and amine were the major malodorous pollutants emitted from landfill and influenced the residential area. Through a coefficient of divergence analysis, the CDjk values of Sites A (0.66) and B (0.69) were lower than others, indicating the effects of odor emission on the surrounding residential area were slightly more severe than on the other sites because of the meteorological condition during the study period. The results of this study can provide essential information to enhance understanding the actual odor emission intensity and characteristics of landfill and the migration, transportation and influence of odorant emissions on the working surface of the landfill.
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•Various VOCs from a typical landfill were monitored and distinguished.•The most abundant odorous contributors to total odors were calculated.•Malodorous landfill gases had a slightly effect on residential areas.
Continuing previous studies, reviewed by modeling transmission mecha-nisms with the definition of one of the major criteria of transmission efficiency – the efficiency of the gearing, which depends ...on the geometry and kinematics of the working surfaces of the engagement and position of the contact point on the engaging surface in the object of the simulation model the designed transmission.
This article is about potato feather sorting machines. There are mechanical and automatic types of potato sorting machines. In turn, there are types of mechanical potato sorting machines in drum, ...conveyor, roller and sieve types. While automatic sorting machines have laser, ultrotovushli, rengenli, video visual, spectral and optical intelligent sorting machines. Among mechanical sorting machines, vibration sieve-type devices stand out, with simplicity of construction and high performance. Vibration movement in the sorting machine of potato tugs, the working device of which is sieve type, accelerates the sorting process. However, it is important to determine the optimal values of the vibration parameters. The correct selection of its values ensures that the potato feathers are clearly sorted according to the degree of damage and external dimensions on the working surface. This is accompanied by a high level of work productivity and a decrease in the time of sorting. Therefore, this article presents a brief description of the determination of the optimal amplitude of the vibrational working surface through the differential equations of the machine developed for sorting potato feathers and the results of their analysis. Graphs of differential equations are generated automatically by writing codes in the “Maple 2017” program.
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