scholarly journals Determination the conductor sag according to the period of own harmonic oscillations

2020 ◽  
Vol 220 ◽  
pp. 01036
Author(s):  
Danil Yaroslavsky ◽  
Van Vu Nguyen ◽  
Marat Sadykov ◽  
Mikhail Goryachev ◽  
Dmitry Ivanov ◽  
...  
Keyword(s):  
The Body ◽  
Power Lines ◽  
Physical Pendulum ◽  
Harmonic Oscillations ◽  
Mechanical Loads ◽  
Straight Line Passing ◽  
Straight Line ◽  
Line Passing ◽  
Fixed Axis ◽  
Overhead Power Lines

The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The article briefly describes an algorithm for calculating the conductor sag for the case when the conductor suspension points are at the same height. The results obtained using the developed model for calculating the sag of the conductor by its period are compared with the available experimental data. Experimental equipment is described. The error of the method is estimated.

scholarly journals Model of own harmonic conductor oscillations for tasks of monitoring the status of airline power transmission lines

2020 ◽  
Vol 22 (3) ◽  
pp. 97-106
Author(s):  
D. A. Yaroslavskiy ◽  
V. V. Nguyen ◽  
M. F. Sadykov ◽  
M. P. Goryachev ◽  
A. A. Naumov
Keyword(s):  
Transmission Lines ◽  
Mechanical Load ◽  
Power Line ◽  
The Body ◽  
Power Lines ◽  
Physical Pendulum ◽  
Mechanical Loads ◽  
Straight Line Passing ◽  
Overhead Power Lines ◽  
Overhead Power Line

The article substantiates the relevance of the inspection of overhead power lines by determining the mechanical loads of the conductors. The conductor sways under the action of external loads and variable internal mechanical loads. The conductor behaves in span like a pendulum. Using the inclinometric method, it is possible to determine the deviations of the conductor in space from its equilibrium position. Having restored the geometry of the conductor in the span of an overhead power line, mechanical loads can be determined. A model of the harmonic oscillations of the conductor in flight is derived to assess the mechanical loads of the conductor overhead power lines. This mathematical model is based on mathematical models of a flexible thread and a model of a physical pendulum. A conductor is a physical pendulum, where the conductor acts as the body, and in the role of the fixed axis of rotation, a straight line passing through the suspension points of the conductor. The developed model allows you to determine the arrow of its sag from the period of oscillations of the conductor in the span. The article considers algorithms for calculating the conductor sag arrows for two cases: the conductor suspension points are at the same height; conductor suspension points are at different heights. A theoretical calculation is given for a model of a span overhead power line with an estimate of the sensitivity of the developed model and its error in determining the sag of the conductor. Using the arrow of the conductor sag, you can restore its geometry, and hence the mechanical load of the conductor. Therefore, knowing the initial geometric parameters of the span of the overhead power line and the current period of the conductor’s oscillations, it is possible to examine its current state.

scholarly journals Pattern Recognition: Parameters of Body Inrun Position at the Beginning of Take-Off

2018 ◽  
Vol 18 (4) ◽  
pp. 214-220
Author(s):  
A. V. Kazmiruk ◽  
V. I. Banakh ◽  
A. P. Vlasov ◽  
A. O. Lopatiev ◽  
O. F. Tovstonoh ◽  
...  
Keyword(s):  
Discriminant Function ◽  
Inclination Angle ◽  
Body Position ◽  
The Body ◽  
Mean Values ◽  
Straight Line Passing ◽  
Starting Position ◽  
Ski Jumping ◽  
Straight Line ◽  
Line Passing

The purpose of the paper is to determine the differences in the technique of body inrun position at the beginning of take-off in junior ski jumpers of different qualifications (athletic preparedness). Materials and methods. The study participants were 22 junior ski jumpers aged 14-15 (a group of junior ski jumpers) during the Ukrainian Ski Jumping Championship (October 9, 2010, Vorokhta, Ukraine) and 33 ski jumpers aged 16-17 (a group of senior ski jumpers) who took part in the international competitions “Lotos Cup” in January 2010. The study analyzed the videos of take-offs of 22 athletes aged 14-15 and 33 athletes aged 16-17. The parameters of ski jumping technique and sports results were processed on the basis of video materials of the first competition series. Results. There are significant differences (p < 0.001) in the mean values of corresponding parameters of the body position at the beginning of take-off. The data point to a tighter tuck of the body of the athletes aged 16-17. The structure coefficients of the first canonical discriminant function indicate that the function is most significantly related to the values of angles 10 (ν); 8 (ζ); 6 (θ): the inclination angle of the segment of the straight line passing through the axes of the hip and ankle joints (ν) towards the direction of the skier’s movement; the inclination angle of the segment of the straight line passing through the general center of body weight and the axis of the ankle joint (ζ) towards the direction of the skier’s movement; the inclination angle of the head towards the trunk (θ). The athletes aged 16-17 differ from the athletes aged 14-15 by the parameters characterizing the body’s tuck in the starting position – the position at the beginning of take-off. Conclusions. The unstandardized canonical discriminant function coefficients can be used to classify the levels of proficiency in the body’s tuck in the starting position – the position at the beginning of take-off in athletes aged 14-17.

scholarly journals Physical properties of surfaces. II—Viscous flow of liquid films. The range of action of surface forces

1935 ◽  
Vol 151 (872) ◽  
pp. 220-233 ◽  
Author(s):  
S. H. Bastow ◽  
Frank Philip Bowden ◽  
Thomas Martin Lowry
Keyword(s):  
Viscous Flow ◽  
Freezing Point ◽  
Applied Pressure ◽  
Liquid Films ◽  
Appreciable Effect ◽  
Straight Line Passing ◽  
Straight Line ◽  
Fluid Properties ◽  
Line Passing ◽  
Induced Structure

The present paper describes experiments which were carried out in order to determine the extent to which the fluid properties of water and other liquids may be modified by the presence of a solid surface. For this purpose, measurements of the viscous flow of a liquid very near to a surface are particularly suitable, since they provide a sensitive test for the existence of any induced structure in the liquid. If the surface has no appreciable effect, the smallest applied pressure will cause the liquid to flow and the rate of flow plotted against pressure will give a straight line passing through the origin, see fig. 3. If, however, as many authors have suggested, long chains of oriented liquid molecules with a definite rigidity are formed by the influence of the surface, the liquid will show a resistance to shear, which will be specially evident at low pressures; Poiseuille’s law will not hold and the pressure-flow curve will be of the form shown in fig. 4. A method has been developed for measuring the viscosity of thin liquid films enclosed between flat polished surfaces of glass and steel. The film thickness can be varied from about 10 -5 cm to any desired distance and can be accurately determined. The experiments show that films of a liquid, known to possess a bulk structure (liquid crystal), possess a high rigidity, but there is no sign of induced structure in normal liquids even with very thin films and at temperatures near the freezing point.

Spinor-Based Attitude Determination with Star Sensor Considering Depth

2021 ◽  
Vol 87 (8) ◽  
pp. 551-556
Author(s):  
Qinghong Sheng ◽  
Rui Ren ◽  
Weilan Xu ◽  
Hui Xiao ◽  
Bo Wang ◽  
...  
Keyword(s):  
Attitude Determination ◽  
Geometric Condition ◽  
Depth Information ◽  
Star Sensor ◽  
Imaging Geometry ◽  
Straight Line Passing ◽  
Geometry Model ◽  
Straight Line ◽  
Order Of Magnitude ◽  
Line Passing

A star sensor is a high-precision satellite attitude measurement device. Since its observation information has only two-dimensional direction vectors, when a star sensor is used for attitude determination the dimension of the observation information is less than the number of attitude angles determined, so mainstream algorithms usually only guarantee the accuracy of the pitch angle and the roll angle. In view of the lack of depth information in the observation's imaging geometric condition, this article proposes a spinor-based attitude determination model, which describes a straight line passing through two stars with the spinor and maps the depth information of the straight line with the pitch, to establish an imaging geometry model of the spinor coplanar condition. Experiments show that the yaw-angle attitude accuracy of the method is an order of magnitude better than that of mainstream algorithms, and the accuracy of the three attitude angles reaches the arc-second level.

scholarly journals A mathematical model of odor dispersion from a wastewater treatment plant

2019 ◽  
Vol 138 ◽  
pp. 01029
Author(s):  
Valerii Azarov ◽  
Tat’yana Solov’eva ◽  
Sergei Svitskov
Keyword(s):  
Mathematical Model ◽  
Wind Direction ◽  
Treatment Plant ◽  
Straight Line Passing ◽  
Straight Line ◽  
Odor Character ◽  
Line Passing ◽  
Kaliningrad Region ◽  
Odor Dispersion

Smell is an important criterion of the quality of atmospheric air. The paper looks at quantitative and qualitative methods of odor assessment and describes the method of field olfactometry. Studies were carried out on the spread of odor from the WWTP OAO OKOS in the Kaliningrad region of Russia which resulted in 817 measurements. For each measurement, the following parameters were recorded: odor strength (D/T), odor character, atmospheric pressure (mmHg), temperature (°C), relative humidity (%), wind speed (m/s), wind direction and the the point where a measurement was taken. A mathematical model is given of the dependence of odor strength on the distance to two sources s1 (m) and s2 (m) and the wind direction from a straight line passing through a given point and a source 1 — a1 or a source 2 — a2.

scholarly journals THE RELATION BETWEEN CHLOROPHYLL CONTENT AND RATE OF PHOTOSYNTHESIS

1935 ◽  
Vol 18 (4) ◽  
pp. 573-597 ◽  
Author(s):  
Walter E. Fleischer
Keyword(s):  
Chlorophyll Content ◽  
Similar Data ◽  
Straight Line Passing ◽  
Iron Supply ◽  
Similar Relation ◽  
Straight Line ◽  
Rate Of Photosynthesis ◽  
Line Passing

1. Data are presented which support the conclusion of Emerson (1929) that the rate of photosynthesis is proportional to the chlorophyll content when the latter is varied by varying the iron supply. These data give a straight line passing through the origin, which is not true of Emerson's results. 2. Similar data are presented which show that a similar relation exists when nitrogen controls the chlorophyll content. 3. Evidence is given which indicates that magnesium plays a part in the process of photosynthesis in addition to its effect upon the chlorophyll content.

scholarly journals The complex moment problem: determinacy and extendibility

2019 ◽  
Vol 124 (2) ◽  
pp. 263-288 ◽  
Author(s):  
Dariusz Cichoń ◽  
Jan Stochel ◽  
Franciszek Hugon Szafraniec
Keyword(s):  
Partial Solution ◽  
Positive Definite ◽  
Lattice Points ◽  
Moment Sequence ◽  
Representing Measure ◽  
Straight Line Passing ◽  
Straight Line ◽  
Plane Algebraic Curve ◽  
Line Passing ◽  
Point Set

Complex moment sequences are exactly those which admit positive definite extensions on the integer lattice points of the upper diagonal half-plane. Here we prove that the aforesaid extension is unique provided the complex moment sequence is determinate and its only representing measure has no atom at $0$. The question of converting the relation is posed as an open problem. A partial solution to this problem is established when at least one of representing measures is supported in a plane algebraic curve whose intersection with every straight line passing through $0$ is at most one point set. Further study concerns representing measures whose supports are Zariski dense in $\mathbb{C} $ as well as complex moment sequences which are constant on a family of parallel “Diophantine lines”. All this is supported by a bunch of illustrative examples.

Loci of Points Equally Spaced From Two Given Geometrical Figures. Part 1

2017 ◽  
Vol 5 (3) ◽  
pp. 21-35 ◽  
Author(s):  
Владимир Вышнепольский ◽  
Vladimir Vyshnyepolskiy ◽  
Николай Сальков ◽  
Nikolay Sal'kov ◽  
Е. Заварихина ◽  
...  
Keyword(s):  
Cylindrical Surface ◽  
Parabolic Cylinder ◽  
Straight Line Passing ◽  
Sphere Center ◽  
Positive Gaussian Curvature ◽  
Straight Line ◽  
Paraboloid Of Revolution ◽  
Line Passing ◽  
The One ◽  
The Given

Loci of points (LOP) equally spaced from two given geometrical figures are considered. Has been proposed a method, giving the possibility to systematize the loci, and the key to their study. The following options have been considered. A locus equidistant from N point and l straight line. N belongs to l. We have a plane that is perpendicular to l and passing through N. N does not belong to l – parabolic cylinder. A locus equidistant from F point and a plane. In the general case, we have a paraboloid of revolution. The F point belongs to the given plane. We get a straight line perpendicular to the plane and passing through the F point. A locus equidistant from a point and a sphere. The point coincides with the sphere center. We get the sphere with a radius of 0.5 R. The point lies on the sphere. We get the straight line passing through the sphere center and the point. The point does not coincide with the sphere center, but is inside the sphere. We get the ellipsoid. The point is outside the sphere. We have parted hyperboloid of rotation. A locus equidistant from a point and a cylindrical surface. The point lies on the cylindrical surface’s axis. We get the surface of revolution which generatix is a parabola. The point lies on the generatrix of the cylindrical surface of rotation. We get a straight line, perpendicular to that generatrix and passing through the cylinder axis. The point does not lie on the axis, but is located inside the cylindrical surface. We get the surface with a horizontal sketch line – the ellipse, and a front sketch lines – two different parabolas. The point is outside the cylindrical surface. A locus consists of two surfaces. The one with the positive Gaussian curvature, and the other – with the negative one.

Basic slags and mineral phosphates

1925 ◽  
Vol 15 (1) ◽  
pp. 36-46
Author(s):  
Ernest Vanstone
Keyword(s):  
Constant Error ◽  
Soluble Phosphate ◽  
Constant Independent ◽  
Straight Line Passing ◽  
Total Phosphate ◽  
Small Constant ◽  
Straight Line ◽  
Line Passing ◽  
Straight Lines ◽  
The Relationship

(1) The relationship between phosphate soluble in 2 per cent, citric acid and total phosphate present has been investigated in the following cases:(a) Phosphates of known composition.(b) Basic Slags.(c) Mineral Phosphates.(2) The relationship is best shown graphically and in nearly all the above cases is a straight line passing through the origin.For each of three basic slags of widely differing citric solubility, the graphis a straight line showing that citric solubility is a definite constant, independent of the weight taken in the test, when allowance is made for a small constant error in the determination.(3) The ratio soluble phosphate/total phosphate in the case of the mineral phosphates Gafsa, Ephos, Nauru, and a West Indian phosphate, depends on the weight taken in the test, the graphs are not straight lines.

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