DETERMINATION OF THE CHANGE OF THE DESIGN POSITION OF THE PROFILE OF THE BELT CONVEYOR ON THE LOAD OF THE ROLLER BEARINGS

The article attempts to establish the basic patterns in the formation of loads in the structure of the conveyor frame due to changes in the design position of the constituent elements based on analytical calculations. The amortization replacement of rollers and the establishment of a change in the projected resource caused the change in the design position.The aim of the work is to study the interaction of the elements of the belt conveyor on the convex region of the profile when the design position changes and to determine the change in the resource of the roller support elements. The purpose of the work is formulated from the analysis of unplanned stops and premature replacement of conveyor elements, in particular conveyor rollers, on the convex region of the profile.To achieve this goal the influence of the geometric parameters of the convex section of the belt conveyor profile on the force interaction of the belt and roller supports was considered, and the change in the resource of the roller bearings was determined.To characterize the geometric parameters of the convex section of the belt conveyor, the following were selected: the number of roller supports, the distance between the roller supports, the radius of curvature of the conveyor profile, the angle of the curved section. The mathematical model is based on the belt equilibrium equation, which contains the tension forces of the conveyor belt and the forces from the action of roller supports. Particular attention is paid to establishing the effect of changing the geometric parameters of the convex section on the roller bearing life. It has been established that a decrease in the radius of the transitional convex section as a result of a change in the initial design position by 2.4 times leads to an increase in the force acting on the roller support by 161%. It was found that the increase in force is the reason for the rapid exit from the operational state of the rolling bearings of the roller bearings, as evidenced by the intensive drop in the resource of the rollers (18 times).The proposed algorithm for determining the main parameters of the force interaction of the elements of the belt conveyor on the convex region of the profile will make it possible to predict the resource and prevent the conveyor from leaving the premature operational state.

SIMULATION OF THE RADIANT HEAT TRANSFER PROCESS IN THE ELEMENTS OF ROASTING EQUIPMENT

The object of the research is the process of radiation heat transfer, taking into account a single reflection of rays in the IR device of food production. Investigated problem – the work is devoted to solving the problem of irregularity of radiation heat transfer during infrared roasting of food products. Main scientific results. The inverse problem of heat transfer by radiation has been solved and a technique has been developed for determining the profiles of the ray flux reflectors for uniform irradiation of receivers of a convex section. Analytical modeling of all-round uniform irradiation of an elliptical receiver has been carried out. An experimental device with low-inertia temperature sensors for infrared roasting of semi-finished meat products has been developed, which makes it possible to use a reflector shaped according to the developed analytical technique. The verification of the created technique for determining the profiles of reflectors by means of a computer experiment using the TracePro and Mathcad software systems has been carried out. The area of practical use of the research results: the use of an experimental device with a radiant flux reflector for roasting semi-finished meat products proves that the obtained technique for profiling reflectors of heat engineering systems is acceptable for the design of infrared equipment for food production and restaurant facilities. This technique allows simulating the profile of the radiant flux reflector depending on the shape of the receiver. Studies have shown that the use of a profiled reflector in the experimental device reduces the duration of roasting of natural portioned semi-finished beef products by 33 %. Innovative technological product: a technique for determining the profiles of ray flux reflectors for uniform irradiation of receivers with a convex section. Device for infrared roasting of semi-finished meat products. Scope of application of an innovative technological product. The study of an experimental device with a designed radiant flux reflector for roasting semi-finished meat products proves that the obtained technique for profiling reflectors of heat engineering systems is acceptable for the design of infrared equipment for food production and restaurant facilities. Using this approach allows to approach the solution of the problem of irregularity of irradiation of products during infrared roasting

Detection of degenerate points on the surface

Landslides, bifurcations, multi-saddles and remnants of terraces are distinctive landforms. Some points on the surfaces of these objects are degenerate points. This may help us with their automatic recognition and identification. All first-order and second-order partial derivatives of analyzed function are necessary for detection of degenerate points. Terrain slope, curvatures and Hessian are required for classification of degenerate points. The paper is aimed at detection of fossil landslides. A point of landslide surface where the concave section of thalweg is turning into convex section of ridge line is a degenerate point. Two zero isolines of Hessian and zero isoline of profile, streamline and plan or tangential curvatures pass through this point. Final result of the detection procedure depends to a great extent on the quality of DEM and accuracy of derivatives.

Detection of degenerate points on the surface

Landslides, bifurcations, multi-saddles and remnants of terraces are distinctive landforms. Some points on the surfaces of these objects are degenerate points. This may help us with their automatic recognition and identification. All first-order and second-order partial derivatives of analyzed function are necessary for detection of degenerate points. Terrain slope, curvatures and Hessian are required for classification of degenerate points. The paper is aimed at detection of fossil landslides. A point of landslide surface where the concave section of thalweg is turning into convex section of ridge line is a degenerate point. Two zero isolines of Hessian and zero isoline of profile, streamline and plan or tangential curvatures pass through this point. Final result of the detection procedure depends to a great extent on the quality of DEM and accuracy of derivatives.

DEM Simulation in Effects of the Section Structure of Smooth Rigid Wheel on Dynaminc Mechanical Behavior of Lunar Soil Simulant

The simulation system between smooth rigid wheel and lunar soil by Discrete Element Method (DEM) was established and validated. Three section structures of smooth rigid wheel, including flat, concave and convex structures were designed. The effects of these three different wheel section structures on dynamic mechanical behaviors of lunar soil simulant were simulated by PFC2D®. The simulation results indicated that the concave section structure of smooth rigid wheel has the best anti-sinkage ability, the convex section structure has the good anti-sinkage ability, and the flat section structure has the worst anti-sinkage ability.

Influence of Blue Light on the Leaf Morphoanatomy of In Vitro Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae)

Kalanchoe pinnata (Lamarck) Persoon (Crassulaceae) (air plant, miracle leaf) is popularly used to treat gastrointestinal disorders and wounds. Recently, the species was tested to treat cutaneous leishmaniasis with successful results. This medicinal activity was associated with the phenolic fraction of the plant. Blue light induces biosynthesis of phenolic compounds and many changes in anatomical characteristics. We studied the effects of supplementary blue light on the leaf morphology of in vitro K. pinnata. Plants cultured under white light (W plants) only and white light plus blue light (WB plants) show petioles with plain-convex section, amphistomatic leaf blades with simple epidermis, homogeneous mesophyll with densely packed cells, and a single collateral vascular bundle in the midrib. W plants have longer branches, a larger number of nodes per branch, and smaller leaves, whereas WB plant leaves have a thicker upper epidermis and mesophyll. Leaf fresh weight and leaf dry weight were similar in both treatments. Phenolic idioblasts were observed in the plants supplemented with blue light, suggesting that blue light plays an important role in the biosynthesis of phenolic compounds in K. pinnata.

Native-induced secondary plant succession in the Mackenzie River delta, Northwest Territories, Canada

Plants introduced by man play a very minor role in the flora of the Mackenzie River, delta and are primarily restricted to centres of habitation such as Inuvik, Aklavik, and Reindeer Station (Map 1) (Cody, 1965; Gill, 1971). Within the delta itself, however, a number of introduced species are recurringly present on one geomorphic position, the point bar, which forms the convex section of a meander bend in flood plains and deltas (Fig 1). The Mackenzie delta supports a northerly extension of the boreal forest, and most of the higher levees are occupied by trees, particularly White Spruce Picea glauca. Point bars are constructed of coarser alluvium than other delta landforms, thus they have a drier and warmer soil environment than other locations (Gill, 1972a); vegetation response to this locally ameliorated environment has been such that virtually every point bar in the Mackenzie delta is occupied by a discrete plant community dominated by Balsam Poplar Populus balsamifera (Gill, 1972b). The poplar stands are surprisingly well developed for such a northerly latitude, 68°45′N (Fig 2).