Quadratic flat involutions as a basic method of obtaining curves in the systems of CAE

The way of setting up non-central quadratic flat involutions, based on application of pencils of circles is suggested, transformation operators are introduced, and the examples of rational circular curves constructed by this method are given

Analysis of air pollution from industrial plants by lichen indication on example of small town

According to the research the species of lichens such as Parmelia sulcata, Parmeliopsis ambigua, Phiscia stellaris, Xanthoria parietina are founded on example of small town. Values of clear air index correlated with the average content of sulphur dioxide in the air. These measurement points correspond to residential areas and regions of the objects of food industry. Two zones zero projective coverage are selected. These most polluted zones corresponded to the location of the metallurgical industry and heat electropower station. The roof production and abrasive industry do not show a significant increase in the concentration of sulfur dioxide in the contiguous territory. By method lichen indication on example of small city two zones lichen deserts (sulfur dioxide concentration greater than 0.3 mg/m{3}) and one area of critical pollution (sulfur dioxide concentration of 0.1 -0.3 mg/m{3}) were founded. The largest area of air pollution allegedly linked to the activities of plants. Thus metallurgical industry and heat electropower station can be called major air pollutants in small towns

Research on Geometrical Errors of Geokhod Prototype Shell Based on Coordinate Control Data

The article contains results of a research on geometric accuracy of a geokhod prototype shell. The article outlines the general structural features of geokhod bodies, and the main principles of manufacturing in test production. An overview of approaches to modeling of shell error occurrence is given. The researches were conducted on the basis of data obtained by coordinate control over the stabilizing section shell. The data were studied by statistical methods and analyzed in terms of their compliance with previously proposed mathematical models of formation of geokhod shell inaccuracies. It is shown that available mathematical models can not completely explain the origin of all the errors. The authors attribute unexplained geokhod shell errors as deformations caused by welding

Solution of the Applied Task to Determine Total Exposure for Mechanical Engineering Workers

In everyday life, people repeatedly exposed to ionizing radiation. Radiation sources is as natural background radiation due to the natural radioactivity of the earth, cosmic and solar radiation and artificial emitters in enterprise engineering. Therefore, the determination of the total human exposure in engineering industry will consist of a variety of factors will be strictly defined for a specific person, and undoubtedly true. Neural network technology can completely resolve this problem, follow neyroalgoritm presented in this paper

Determination of the Absorption Coefficient and Cloudiness Multiplicity Attenuation During the Gamma-Radiation Passage

The paper presents background value equivalent dose of gamma-radiation investigation in different weather: clear cloudy and overcast. The change of the dose rate of gamma radiation, depending on the weather and the ability cloudiness to shield gamma rays is shown. A new method for eliminating the consequences of accidents at nuclear power plants or plants using radioactive elements is proposed. A calculation method of cloudiness coefficient absorption and cloudiness gamma-radiation multiplicity attenuation is developed. The gamma- radiation multiplicity attenuation and the absorption coefficient of gamma radiation were calculated

Propagation of Magnetic Fields from Electrical Domestic Appliances

The article presents a research into propagation of magnetic fields from electrical domestic devices. A safe distance at which magnetic induction does not exceed the background level is determined for each type of devices. It is proved that there are two stages of increasing magnetic induction as the distance from the source increases. At the first stage magnetic induction rises and electromagnetic field is formed. At the second stage exponential decrease of magnetic field induction takes place. Mathematical regularities of propagation of magnetic field from electrical domestic devices are experimentally educed

Improvement of the Sintered Surface and Bulk of the Product Via Differentiating Laser Sintering (Melting) Modes

Selective laser sintering (melting) enables using metal powdered materials to manufacture products of any geometrical complexity, requiring no preliminary costs to prepare processing equipment. However, quality of the sintered surface is often inadequate as against the product manufactured traditionally. Manufacturing a high quality product requires solution of such vital task as prediction of the sintered surface roughness. The authors address to the effect of laser sintering modes on roughness of the surface, sintered of copper powdered material PMS-l (IIMC-1). The dependence of roughness of the surface layer sintered of copper powder material PMS-l upon sintering process conditions is expressed mathematically. The authors suggest differentiating sintering modes to improve the sintered surface and the bulk of the product and dividing them into rough, semi-finishing, and finishing ones

Influence of layer-by-layer laser sintering conditions on the quality of sintered surface layer of products

The influence of technological modes of sintering: the displacement velocity of laser beam V, laser power P, scanning step S and preheating temperature of powder material t on the quality of sintered surface layer of aluminum powder PA-4, copper powder PMS-1 and cobaltchromium- molybdenum powder DSK-F75 were studied

Oxidative Activity of Heated Coal Affected by Antypirogens

The effect of antypirogens on chemical activity of heated coal is studied. It is proved that ammonium sulfate, calcium phosphate, calcium chloride, calcium nitrate and acid fluoride are the most effective antypirogens

Research on Geometric Errors of Intermediate Unit Shell of a Geokhod

This article includes the research results on production errors of intermediate unit shell of a geokhod prototype model. There has been a problem stated concerning the accuracy of geokhod shells; constructive and technological particularities of a intermediate unit have been specified. A short summary has been conducted of the types of approach to the determination of shell errors of large equipment. The research was performed on the basis of data received by means of coordinate control of a gekhod prototype model in a production environment. The captured data have been researched by means of statistical methods and analyzed with the purpose of unveiling the factors affecting the errors. It was showed in the article that the errors can be partially explained by the production errors of body sectors and the errors of their relative assembling position. It was demonstrated that at least a part of errors is conditioned by reasons which are not taken into account in the process of a pure geometric description of the intermediate unit manufacturing process