The research was performed at the Faculty of Veterinary Medicine of the Latvia University of Agriculture. At the moment the research in veterinary anaesthesia is in its infancy stage. The aim of this study was to determine the effects of the acepromazine maleate on intraocular pressure (IOP) and horizontal pupil diameter (HPD) in a dog's eye. Ten adult dogs of different age, breed and sex were examined clinically and ophthalmologically. All animals were clinically and ophthalmologically healthy. Animals received acepromazine intramuscularly. IOP and HPD were measured every 5 minutes for the total period of 60 minutes. It was established that the acepromazine maleate intramuscular injection causes an IOP decrease in booth eyes. A significant IOP decrease was observed from 35 till 60 minutes after the acepromazine injection. The pupil contraction was observed 5 minutes after the treatment and continued to contract till the end of the research. As acepromazine maleate causes a significant decrease of intraocular pressure, it is not contraindicated to be used in the case of corneal trauma, perforation, glaucoma and corneal ulcers.

This paper presents results of pressure oscillation investigation in hydraulic hitch-system of a tractor Claas Ares ATX 557 during the motion during artificial roughness road test. During experiments oscillation at different driving speed, tyre pressure and hitch-system oscillation damping (turned on/off) were investigated. Tractor hydraulic hitch-system was equipped with a pressure sensor Wika Transmitter ECO-1 and data processing software PicoLog. Results of experiments present maximum pressure peak of 210 bar in the tractor hydraulic system when hydraulic hitch-system oscillation damping system at driving speed 8 km·hE-1 is not used and system pressure peak reduces to value of 180 bar if the hydraulic hitch-system oscillation damping is used.

In order to perceive the pressure oscillation in the hydraulic hitch-system of the tractor and oscillation of the whole tractor aggregate at different loads on the hitch-system, a physical model is used. Changing the position of weight on physical implement boom, different moments of inertia were obtained and the appropriate load on the hydraulic hitch-system hydro cylinder. Results of driving experiments on the artificial roughness road present the maximum pressure peak of 220 bar in the tractor hydraulic system when weight was placed on further position, and the driving speed was 8 km hE-1 and tyre pressure was 1.2 bar. At the driving speed of 11.2 km hE-1 and with the same tyre pressure, the hydraulic system pressures reached up to 212 bar. On the weight on the middle position of boom, pressure in the hydraulic hitch-system reached 172 bar at the driving speed of 7.8 km hE-1 and tyre pressure of 1.2 bar, but at the driving speed of 11.2 km hE-1 and at the same tyre pressure, the hydraulic system pressures reached 165 bar. If the weight was placed on nearest position, pressure in the hydraulic hitch-system reached only 85 bar at the driving speed of 7.8 km hE-1 and tyre pressure - 1.2 bar, but at the driving speed of 11.2 km hE-1 and at the same tyre pressure, it was 98 bar. The investigation of the physical tractor-implement model allows the determination of the conformity of the physical model with real harrow implement.

This paper investigates the effect of intake runner design on pressure wave propagation and reflection in sparkignited internal combustion (IC) engine. These events are known to leave a noticeable influence on the overall engine performance therefore the aim of this study is to evaluate how changes in intake runner geometry affect pressure oscillations and volume flow rate. Time-dependent computational fluid dynamics (CFD) analysis was carried out to determine how these changes affect the pressure oscillations during a full engine cycle at constant crankshaft speed. Steady state CFD analysis at constant pressure differential was carried out to evaluate the effect on volume flow rate. The simulations were carried out in SolidWorks Flow Simulation environment. Honda CRF450R motorcycle engine was used to define the initial conditions and basic intake runner design. Intake air speed at port entrance cross-section was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the intake port opening cross-section. Six different intake runner designs were compared. It was concluded that the runner taper angle has influence on pressure wave-length but internal geometry (steps, curvature and taper angle) has influence on volume flow rate. It was observed that cylindrical intake runner design produced an increase in pressure wave-length but a cylindrical section of the intake runner with a stepped transition to tapered extension produced a slight increase in pressure wave amplitude.