scholarly journals Investigation of automatic driving of a mobile wide span agricultural vehicle in the wake of a constant technology track

2020 ◽  
pp. 12-26
Author(s):  
V. M. Bulgakov ◽  
V. P. Kuvachov ◽  
I. V. Holovach ◽  
Ye.I. Ihnatiev
Keyword(s):  
Laser Beam ◽  
Theoretical Research ◽  
Pilot Studies ◽  
Positioning Systems ◽  
Automatic Driving ◽  
Effective Implementation ◽  
Left And Right ◽  
Experimental Researches ◽  
Analytical Expressions

Annotation Purpose. Determination of regularities of influence of parameters of bridge agricultural means and system of its automatic driving in the wake of a constant technological track on kinematics of its onboard (force) turn and development of the basic ways of development of automatic driving theory of specialized wide span agricultural means. Methods. Theoretical researches, synthesis of constructive schemes and parameters of the bridge agricultural means were carried out by modeling on the personal computer of conditions of its functioning. Bases of the theory of a tractor and theoretical mechanics with use of a Mathcad package are the basis for methods of research. Pilot studies of wide span agricultural means and implementation of the offered way of its automatic driving in the wake of a constant technology track with use of a laser beam were carried out in specially equipped laboratory. Results. For theoretical research of process of automatic driving of wide span agricultural means possible conditions of implementation of onboard (power) turn by it are considered. The equivalent scheme of forces and kinematics of onboard turn is constructed, on the basis of which the received analytical expressions which connect among themselves design, kinematic and power data of wide span agricultural means, at which perhaps effective implementation of onboard turn. It is also established that perspective and effective for automation of driving of wide span agricultural means in the wake of a constant technology track with purely onboard (power) method of its turn is uses of a laser beam as trajectory sensor. Thus the received analytical dependence for determination of accuracy of an arrangement of a laser emitter from the left and right side of a constant technology track depending on the set accuracy of giving of a laser beam. Keywords: track and bridge systems of agriculture, wide span agricultural means, driving automation, local positioning systems, theoretical and experimental researches, accuracy.

About the concept of synthesis of high-performance detection and positioning systems in the areas of elements falling, separated from strategic and space missiles on the trajectories of their flight during tests and regular operation

2018 ◽  
pp. 10-21
Author(s):  
G. G. Vokin
Keyword(s):  
High Performance ◽  
Physical Nature ◽  
Positioning Systems ◽  
Physical Conditions ◽  
Highly Efficient

The article describes the approach and topical issues of synthesis of highly efficient transportable systems for search and determination of coordinates in the areas of elements falling, separated from the missiles, taking into account the dislocation of pre-empted areas of fall and physical conditions in their territories. The principles of these systems are based on the rational integration of traditional and non-traditional information sensors of different physical nature, which record the moments of landing of separated parts of the missiles.

Diagnostics of the location of damage to tubing oil well pipes

2019 ◽  
Vol 5 (4) ◽  
pp. 115-128
Author(s):  
Timur A. Ishmuratov ◽  
Rif G. Sultanov ◽  
Milyausha N. Khusnutdinova
Keyword(s):  
Fluid Motion ◽  
Oil Well ◽  
General Belief ◽  
Oil Flow ◽  
Specialized Equipment ◽  
Improving Accuracy ◽  
Analytical Expressions ◽  
Technical Measures ◽  
Quick Determination

The study is devoted to the mathematical description of the process of oil outflow in places of leakage of the tubing string, which allows a computer to locate a leakage in the tubing. The authors propose methodology for identifying defects in the tubing and determining the location of the leak. The uniqueness of this methodology lies in quick determination of the place of leakage without the use of specialists, sophisticated and specialized equipment. Mathematical modeling of oil flow in the tubing requires the apparatus of continuum mechanics. It is a general belief that the movement of oil in the pipe flows at low speeds due to its outflow from the hole. Using the general equations of mass and energy balance, the authors have obtained differential equations of fluid motion in a vertical pipe in the process of its outflow from the tubing and in the process of injection. Analytical expressions are the solution to these equations, as they can help in estimating the degree of damage and its location, as well as the feasibility of its eliminating. The results show that an increase in the leakage and injection times leads to improving accuracy of locating damage. Thus, when conducting various geological and technical measures (GTM) at the well, it is possible to assess the presence of leakage and its intensity when deciding on the repair of tubing.

scholarly journals The Relationship between Foot Status and Motor Status in Preschool Children: A Simple, Comparative Observational Study

Healthcare ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 936
Author(s):  
Milan Kojić ◽  
Branka Protić Gava ◽  
Milan Bajin ◽  
Marko Vasiljević ◽  
Jasmina Bašić ◽  
...  
Keyword(s):  
Preschool Children ◽  
Observational Study ◽  
Total Sample ◽  
Nonparametric Tests ◽  
Significance Level ◽  
Flat Feet ◽  
Significant Difference ◽  
Left And Right ◽  
The Relationship

Background: The research objective of the study is to determine the differences in the manifestation of the motor status of normally fed preschool test subjects, classified into groups according to foot status. Methods: This is a simple, comparative observational study. Preschool children included in this study have been subjected to anthropometric measurements in order to determine BMI, tests for motor skills assessment (running at 20 m from a high start, standing broad jump, backwards polygon, rectangular seated forward bend, plate tapping, sit-ups for 60 s, and bent arm hang), and a determination of foot status. The total sample was comprised of 202 test subjects who attended a regular sports program, aged 3.9 to 6.5 years of decimal age (M = 141; Age = 5.3 ± 0.74; Height = 117.3 ± 7.1; Weight = 22 ± 3.7; F = 61; Age = 5.1 ± 0.73; Height = 114.9 ± 7.4; Weight = 21.2 ± 3.8), of which 153 (75.7%) were normally fed, 6 (3%) were undernourished, 30 were overweight (14.9%), and 13 were obese (6.4%). Results: In the total sample, 30 (14.9%) subjects had normal arch feet, 90 (44.6%) high arched feet, and 41 (20.3%) flat feet. We found 41 (20.3%) subjects who had different left and right foot statuses within this sample. The data were processed by means of nonparametric tests (the Kruskal–Wallis and Mann–Whitney U tests) at a significance level p ≤ 0.05. Conclusion: The results show that there is a statistically significant difference between groups of subjects with different foot statuses in the manifestation of motor status in most tests, with a significance level of p ≤ 0.01, and in tests of sit-ups for 60 s and the bent arm hang, there is a statistically significant difference, the level of which is p ≤ 0.05. It is only in the inclination test of rectangular seated forward bend that no statistically significant difference was displayed.

scholarly journals Dual 2-Hydroxypropyl-β-Cyclodextrin and 5,10,15,20-Tetrakis (4-Hydroxyphenyl) Porphyrin System as a Novel Chiral-Achiral Selector Complex for Enantioseparation of Aminoalkanol Derivatives with Anticancer Activity in Capillary Electrophoresis

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 993
Author(s):  
Błażej Grodner ◽  
Mariola Napiórkowska
Keyword(s):  
Capillary Electrophoresis ◽  
Anticancer Agents ◽  
Chiral Discrimination ◽  
Combined Effects ◽  
Pilot Studies ◽  
Repeatability And Reproducibility ◽  
The Stability ◽  
Short Time ◽  
High Separation

In this study, a complex consisting of 2-hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin, (named dual chiral-achiral selector complex) was used for the determination of two novel potential anticancer agents of (I) and (II) aminoalkanol derivatives. This work aimed at developing an effective method that can be utilized for the determination of I (S), I (R), and II (S) and II (R) enantiomers of (I) and (II) compounds through the use of a dual chiral-achiral selector complex consisting of hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system by applying capillary electrophoresis. This combination proved to be beneficial in achieving high separation selectivity due to the combined effects of different modes of chiral discrimination. The enantiomers of (I) and (II) compounds were separated within a very short time of 3.6–7.2 min, in pH 2.5 phosphate buffer containing 2-hydroxypropyl-β-cyclodextrin and 5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin system at a concentration of 5 and 10 mM, respectively, at 25 °C and +10 kV. The detection wavelength of the detector was set at 200 nm. The LOD for I (S), I (R), II (S), and II (R) was 65.2, 65.6, 65.1, and 65.7 ng/mL, respectively. LOQ for I (S), I (R), II (S), and II (R) was 216.5, 217.8, 217.1, and 218.1 ng/mL, respectively. Recovery was 94.9–99.9%. The repeatability and reproducibility of the method based on the values of the migration time, and the area under the peak was 0.3–2.9% RSD. The stability of the method was determined at 0.1–4.9% RSD. The developed method was used in the pilot studies for determining the enantiomers I (S), I (R), II (S), and II (R) in the blood serum.

A-Si:H Ambipolar Diffusion Length and Effective Lifetime Measured by Flying Spot Technique (FST)

1991 ◽  
Vol 219 ◽  
Author(s):  
M. Vieira ◽  
R. Martins ◽  
E. Fortunato ◽  
F. Soares ◽  
L. Guimaraes
Keyword(s):  
Laser Beam ◽  
Transient Analysis ◽  
Diffusion Length ◽  
Transport Equations ◽  
Ambipolar Diffusion ◽  
Schottky Barriers ◽  
Effective Lifetime ◽  
Asymmetrical Distribution ◽  
Flying Spot

ABSTRACTThe determination of the ambipolar diffusion length, L*, and the effective lifetime, τ*, in p/i and a-Si:H Schottky barriers (ITO/p/a-Si:H/Al-Si; Cr/a-Si:H/Cr/Ag) have been determined by Flying Spot Technique, FST. This technique consists in the transient analysis of the photocurrent/photopotential induced by a laser beam that moves perpendicularly to the structure with a constant motion ratio, at different velocities. Taking into account the competition between the diffusion/drift velocities of the excess carriers and the velocity of the flying spot, it is possible to solve the transport equations and to compute separately L* and τ*, from the asymmetrical distribution responses.

Determination of the Effective Depth for Double-Fiber Fluorometric Sensors

1992 ◽  
Vol 46 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Zhong Yuan Zhu ◽  
M. Cecilia Yappert
Keyword(s):  
Fiber Optic Sensor ◽  
Fluorescence Signal ◽  
Acceptance Angle ◽  
Fiber Sensors ◽  
Sample Depth ◽  
Effective Depth ◽  
Different Diameters ◽  
Semi Empirical ◽  
Analytical Expressions

The relationship between the relative fluorescence signal excited and collected with a double-fiber optic sensor and the sample depth has been investigated. The complexity of the analytical expressions for the relative fluorescence signal and the effective depth was reduced by deriving a set of semi-empirical equations which can be evaluated in a simple fashion. These expressions take into account the configuration of the sensor, i.e., fiber diameter, acceptance angle, and separation between fibers. The expressions were tested with the use of double-fiber sensors with different diameters and separations between fibers. The reduction of the effective depth in solutions with significant absorbance was evaluated.

INVESTIGATION OF THE ABSOLUTENESS OF TIME

2021 ◽  
pp. 51-54
Author(s):  
S. Tiguntsev
Keyword(s):  
High Precision ◽  
Gravitational Potential ◽  
High Speed ◽  
Relativistic Effect ◽  
Theoretical Research ◽  
Clock Frequency ◽  
Positioning Systems ◽  
The Earth ◽  
Flow Of Time ◽  
The Difference

In classical physics, time is considered absolute. It is believed that all processes, regardless of their complexity, do not affect the flow of time The theory of relativity determines that the flow of time for bodies depends both on the speed of movement of bodies and on the magnitude of the gravitational potential. It is believed that time in space orbit passes slower due to the high speed of the spacecraft, and faster due to the lower gravitational potential than on the surface of the Earth. Currently, the dependence of time on the magnitude of the gravitational potential and velocity (relativistic effect) is taken into account in global positioning systems. However, studying the relativistic effect, scientists have made a wrong interpretation of the difference between the clock frequency of an orbiting satellite and the clock frequency on the Earth's surface. All further studies to explain the relativistic effect were carried out according to a similar scenario, that is, only the difference in clock frequencies under conditions of different gravitational potentials was investigated. While conducting theoretical research, I found that the frequency of the signal changes along the way from the satellite to the receiver due to the influence of Earth's gravity. It was found that the readings of two high-precision clocks located at different heights will not differ after any period of time, that is, it is shown that the flow of time does not depend on the gravitational potential. It is proposed to conduct full-scale experiments, during which some high-precision clocks are sent aboard the space station, while others remain in the laboratory on the surface of the earth. It is expected that the readings of the satellite clock will be absolutely identical to the readings of the clock in the Earth laboratory.

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