IDENTIFICATION OF THE INFLUENCE OF THE SPATIAL ORIENTATION OF THE DEPOSITED LAYERS, AS WELL AS THEIR OVERLAP COEFFICIENT ON THE SURFACE SHAPE ERROR DURING ADDITIVE SHAPING BY AN ELECTRIC ARC

Статья посвящена изучению вопросов управления процессом аддитивного формообразования изделий. Представлены результаты исследования процесса аддитивного формообразования поверхности электрической дугой в среде защитного газа. Проведен анализ погрешности формы поверхностей, полученных с различным заполнением слоев. Подтверждено экспериментально, что такие параметры процесса, как ориентация слоев, коэффициент их перекрытия являются значимыми. Так, погрешность формообразования образцов наплавки слой на слой в вертикальном направлении выше по сравнению с другими способами наплавки, реализованными в эксперименте. Средние значения погрешности формы образцов составляют 0,75 мм, 0,88 мм, 1,15 мм, соответственно, для способов наплавки слой к слою на горизонтальную поверхность с коэффициентом перекрытия 0,3, слой к слою на горизонтальную поверхность с коэффициентом перекрытия 0,5, слой на слой в вертикальном направлении. Максимальные значения погрешности определены на уровне 0,85 мм, 1,2 мм, 1,5 мм для соответствующих способов наплавки, реализованных в эксперименте. Таким образом, пространственная ориентация слоев, а также коэффициент перекрытия слоев являются значимыми, оказывают влияние на численное значение погрешности формы получаемой поверхности, должны быть учтены при проектировании алгоритмов разделения на слои, их заполнения при аддитивном формообразовании электрической дугой в среде защитного газа The article is devoted to the study of the issues of managing the process of additive shaping of products. The paper presents the results of a study of the process of additive surface shaping by an electric arc in a protective gas medium. We analyzed the error of the shape of the surfaces obtained with different filling layers. We confirmed experimentally that such process parameters as the orientation of the layers, their overlap coefficient are significant. Thus, the error of forming samples of surfacing layer on layer in the vertical direction is higher compared to other methods of surfacing implemented in the experiment. The average values of the sample shape error are 0.75 mm, 0.88 mm, 1.15 mm, respectively, for methods of surfacing layer to layer on a horizontal surface with an overlap coefficient of 0.3, layer to layer on a horizontal surface with an overlap coefficient of 0.5, layer to layer in the vertical direction. The maximum error values are determined at the level of 0.85 mm, 1.2 mm, 1.5 mm for the corresponding surfacing methods implemented in the experiment. Thus, the spatial orientation of the layers, as well as the overlap coefficient of the layers, are significant, affect the numerical value of the shape error of the resulting surface, should be taken into account when designing algorithms for dividing into layers, filling them with additive shaping by an electric arc in a protective gas medium

Solar Energy Potential Evaluation. Case of Study: M'Sila, an Algerian Province

Solar energy is the most important green energy source that may be used to address the problems caused by conventional energy sources. The research in this paper aims to evaluate the solar energy potential of M'Sila, an Algerian internal region, and to determine which technology, among those currently available on the market, is adequate for harnessing that potential for electricity production (PV and CSP). This assessment was based on data (daily temperature and daily solar irradiation) collected at M'Sila weather station for one year and from the NASA site for 34 years from 1984 to 2017. These data were treated with excel 2016 software to determine the total horizontal, diffuse and direct normal solar irradiation. During the study period, the total solar irradiation falling on a horizontal surface in M'Sila (GHI) was estimated to be 1.79 MWh/m2/year. The diffuse solar irradiation incident on a horizontal surface (DHI) and direct normal irradiation, respectively, were estimated to be 594.88 kWh/m2/year, 2117.93 kWh/m2/year. M'Sila is a favourable land for the installation of concentrating solar power plants and photovoltaic panels due to its significant potential energy. The parabolic trough system is recommended. While polycrystalline PV modules should be promoted and installed in M'Sila.

Curious behaviour of spinning coffee cups and other spinning objects

If an empty coffee cup is spun on a horizontal surface about a vertical axis in an anti-clockwise direction, then the whole cup rotates slowly backwards, in a clockwise direction, about a vertical axis located outside the cup. Clues to this curious behaviour are presented by comparing it with other spinning objects.

Interference between Total Solar Radiation and Cloud Cover over Baghdad City

Clouds greatly affect the elements of climate, energy balance, and solar radiation, which has increased the interest of many researchers in trying to find the best relationships and formulas that link these variables. In this work, the data of the European Center for Medium-Range Weather Forecasts (ECMWF) was relied on. The research aims to find the overlap between Cloud Cover (Low, Middle, High, and Total), (LCC, MCC, HCC, and TCC) respectively, with Total Solar Radiation (TSR) of Baghdad city, for the period (1981-2013), the work was carried out with the monthly and annual data of the (Low, Middle, High, and Total) cloud cover and the total solar radiation falling on a horizontal surface. And by using the correlation coefficient Spearman rho test (rs) to find the strength of the relationship between total solar radiation and cloud cover, it was found that there is an inverse relationship between the total solar radiation falling on a horizontal surface and the (Low, Middle, High, and Total) cloud cover.

Tillage unit with new design working bodies for minimal tillage

The design of the tillage unit is presented, with new working bodies made in the form of a holder with rectilinear and oval parts, the rectilinear part is made in the form of a bar made at an acute angle to the horizontal surface and rigidly fixed on a rack with the possibility of dismantling. The lower part of the holder is shaped like an elongated ellipse, the upper oval part of which is a ripper, the lower-a slitter. The height of the ripper and the slitter is the same, on their butt line on the side of the toe, a groove is made for the pointed paw of the cultivator. On the back side of the paw, a groove is made for the holder, while the ratio of the length of the grooves of the paw and the holder is 1:3. The new design of the working body will improve the quality of tillage and water-air balance, increase crop yields and reduce fuel consumption.

Sensitivity of horizontal surface deformation to mantle dynamics from 3D instantaneous dynamics modeling of the eastern Mediterranean region

Geodetically estimated surface motions contain contributions to crustal deformation from coupled geodynamic processes active at all spatial scales and constitute key data for lithosphere dynamics research. Data interpretation methods should therefore account for the full range of possible processes, otherwise risking misinterpretation of data signal and incorrect estimation of lithosphere rheology, stress, or deformation fields. Here we explore the sensitivity of surface deformation to sub-lithospheric processes such as viscous plate-mantle and slab-mantle coupling, variations in slab pull, and buoyancy-driven mantle flow. To this end, we perform 3D instantaneous-dynamics numerical modelling of an elaborately structured compressible crust-mantle system designed for the Eastern Mediterranean Aegean-Anatolian region. We first determine a reference model driven by the absolute motions of the major plates, regional slab pull, a 3D mantle buoyancy field, and modulated by plate boundary coupling and mantle viscosity. The RMS motion data fit of ~5.9 mm/yr of predicted and observed Aegean-Anatolian horizontal surface motions demonstrates that the bulk amplitude of surface motion can be explained by these combined mantle processes. Next, by systematically perturbing reference model features, we assess the crustal sensitivity to each geodynamic driver and to mantle rheology. We find significant changes in crustal velocity gradient amplitudes, often between 10% and 40% of the reference model, with slab morphology effects of up to 93%. This demonstrates the key importance of carefully accounting for each process in modelling lithosphere dynamics. For the Aegean-Anatolia region, we present geodynamic evidence that the Aegean slab pull is the primary driver of the crustal motion field, as was previously suggested from kinematic analysis.

Collision of two coins on a horizontal surface

Oblique angle collisions of two penny coins on a smooth, horizontal surface were filmed with a video camera to investigate the physics of the collision process. If one of the coins is initially at rest, then the two coins emerge approximately at right angles, as commonly observed in billiard ball collisions and in puck collisions on an air table. The coins actually emerged at an angle less than 90 degrees due to friction between the coins, which also resulted in both coins rotating after the collision. At glancing angles, the friction force was due to sliding friction. At other angles of incidence the coins gripped each other and the friction force was then due to static friction.