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1
Дворжак, В. М. "ЗАСТОСУВАННЯ МЕХАНІЗМУ ЧЕТВЕРТОГО КЛАСУ ДЛЯ ПРИВОДУ ВУШКОВИХ ГОЛОК ОСНОВОВ’ЯЗАЛЬНОЇ МАШИНИ." Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 146, no. 3 (January 11, 2021): 15–24. http://dx.doi.org/10.30857/1813-6796.2020.3.1.
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Development and research of functionally-adequate target mechanisms of technological machines of light industry with application of applied CAE-programs. Used the apparatus of vector algebra; analytical and numerical methods for determining the position functions of planar mechanisms containing a structural group of the fourth class of the second order, based on the vector transformation of coordinates; random search method for metric synthesis of flat mechanisms; methods of computer visualization and animation of kinematic schemes of flat mechanisms of higher classes. Mathematical models describing the position functions of the mechanism of eyelets of a warp knitting machine containing a structural group of the fourth class of the second order with rotating kinematic pairs in the form of angles of moving links, free vectors constructed on these links and radius vectors of characteristic points of the mechanism as a function of the angle of rotation of the master crank. The geometrical parameters of the flat six-link mechanism of eyelets for the warp knitting machine containing the structural group of the fourth class of the second order with rotating kinematic pairs as a result of metric synthesis of the mechanism by random search in CAE-program are determined; computer circuit modeling of the obtained mechanism is performed; graphs of visualization and animation of the kinematic scheme of the received mechanism are constructed; identification of the kinematic scheme of the obtained mechanism for compliance with the accepted structure; the received graph of function of position of an auricular needle of the mechanism of the fourth class; the functions of the position of the eye needle of the new mechanism and the mechanism of the basic knitting machine OV-7 are compared. The structure of a flat six-link mechanism, containing structural groups of the fourth class of the second order with rotating kinematic pairs, is proposed for use as a drive in a warp knitting machine on the example of the mechanism of oscillating movement of eyelets. The geometric dimensions of the moving parts of the functionally adequate mechanism of the fourth class for the drive of the eye needles of the basic knitting machine are determined. Software blocks for automated computer metric synthesis and calculation of link angles and radius vectors of characteristic points of the mechanism in the CAE program have been created. Practical Value is to use the results for the design and construction of flat mechanisms of the fourth class with rotating kinematic pairs of warp knitting machines, in which the working bodies make stops during the work process.
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Дворжак, В. М. "ЗАСТОСУВАННЯ МЕХАНІЗМУ ЧЕТВЕРТОГО КЛАСУ ДЛЯ ПРИВОДУ ВУШКОВИХ ГОЛОК ОСНОВОВ’ЯЗАЛЬНОЇ МАШИНИ." Bulletin of the Kyiv National University of Technologies and Design. Technical Science Series 146, no. 3 (January 11, 2021): 15–24. http://dx.doi.org/10.30857/1813-6796.2020.3.1.
Full textAbstract:
Development and research of functionally-adequate target mechanisms of technological machines of light industry with application of applied CAE-programs. Used the apparatus of vector algebra; analytical and numerical methods for determining the position functions of planar mechanisms containing a structural group of the fourth class of the second order, based on the vector transformation of coordinates; random search method for metric synthesis of flat mechanisms; methods of computer visualization and animation of kinematic schemes of flat mechanisms of higher classes. Mathematical models describing the position functions of the mechanism of eyelets of a warp knitting machine containing a structural group of the fourth class of the second order with rotating kinematic pairs in the form of angles of moving links, free vectors constructed on these links and radius vectors of characteristic points of the mechanism as a function of the angle of rotation of the master crank. The geometrical parameters of the flat six-link mechanism of eyelets for the warp knitting machine containing the structural group of the fourth class of the second order with rotating kinematic pairs as a result of metric synthesis of the mechanism by random search in CAE-program are determined; computer circuit modeling of the obtained mechanism is performed; graphs of visualization and animation of the kinematic scheme of the received mechanism are constructed; identification of the kinematic scheme of the obtained mechanism for compliance with the accepted structure; the received graph of function of position of an auricular needle of the mechanism of the fourth class; the functions of the position of the eye needle of the new mechanism and the mechanism of the basic knitting machine OV-7 are compared. The structure of a flat six-link mechanism, containing structural groups of the fourth class of the second order with rotating kinematic pairs, is proposed for use as a drive in a warp knitting machine on the example of the mechanism of oscillating movement of eyelets. The geometric dimensions of the moving parts of the functionally adequate mechanism of the fourth class for the drive of the eye needles of the basic knitting machine are determined. Software blocks for automated computer metric synthesis and calculation of link angles and radius vectors of characteristic points of the mechanism in the CAE program have been created. Practical Value is to use the results for the design and construction of flat mechanisms of the fourth class with rotating kinematic pairs of warp knitting machines, in which the working bodies make stops during the work process.
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Demokritov, Vladimir, and Aleksandr Oleshkevich. "DYNAMICS DESIGN OF MECHANISM OF CRANE TROLLEY MOVEMENT." TRANSPORT 21, no. 4 (December 31, 2006): 284–85. http://dx.doi.org/10.3846/16484142.2006.9638080.
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A crane trolley with a hanging oscillating load was considered. Normal and tangential acceleration of the load and difference between the weight of the load and the strain of the rope are taken into account. Three differential dynamic equations were made. After the solution of the system one nonlinear equation was got; the solution of it was found. Frequency of own vibrations, amplitude and phase were defined taking primary conditions into consideration. The condition of resonance prevention was revealed.
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Meng, Zhao Ming, Ya Bo Qiao, and Zhi Min Fan. "The Optimal Design of Oscillating Oil Cylinder Mechanism of Tire Building Machine." Advanced Materials Research 87-88 (December 2009): 206–10. http://dx.doi.org/10.4028/www.scientific.net/amr.87-88.206.
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according to the poor quality situation that tire building machine presses tire in current market, the thesis analyses the reasons that press roll presses tire uncompactedly and tire layer has bubbles in the process of tire building machine repression. A new design method that is the optimal design of oscillating oil cylinder mechanism of tire building machine is presented. In the premise of meeting the movement performance of mechanism, it not only can maintain that the pressing roll fits in the best pressure, but also enables wave motion of fitting tire pressure in the allowable scope when mechanism is in the dynamic movement. The article cites examples of the design, demonstrates the superiority of the new design method fully.
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Cui, Jian Kun. "Small Tooth Number Difference Planetary Gear Drive with a Crank and Oscillating Block Inputting Mechanism." Applied Mechanics and Materials 52-54 (March 2011): 1268–73. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.1268.
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A new mechanism construction for small tooth number difference planetary gear drive is developed in which the planet wheel is guided by a planar crank and oscillating block mechanism. The sizes of linkage are design dexterously to get an approximate circumference linkage curve so that the engaging condition of internal gear pair can be satisfied. The trajectory of the inner gear center motion is analyzed and its error comparing with a standard circle is calculated to avoid movement interference. The movement of inner gear is study particularly to deduced formula of instantaneous transmission ratio. Despite observable fluctuation of output speed, this new type of gear transmission mechanism still has potential application value in situation with large ratio and low input speed. A hand drive winch prototype using the mechanism is also illustrated in this paper.
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Wang, Guang Xin, Lin Jie Li, Hong Guan, and Tian Min Guan. "Modeling and Simulation for Nutation Drive with Rolling Teeth." Advanced Materials Research 538-541 (June 2012): 470–73. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.470.
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According to the nutation movement of a rotating coin on a table, a novel nutation drive with rolling teeth is presented on the basis of oscillating teeth gear transmission. Firstly, the structure of mechanism is provided and transmission theory is declared. The formulae for calculating the transmission ratio of the mechanism is developed. Secondly, the modeling of this nutation drive is built. Finally, the results of theoretical calculations are verified by dynamic motion simulation of the prototype mechanism. In addition, Numerical control(NC) simulation of machining the stator and the rotor gears is developed.
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Aparisi, Javier, Jose González, and Bernabé Hernandis. "Optimization of an Invention Based on a Force Multiplier Mechanism for Wave Power Generation." Applied Mechanics and Materials 507 (January 2014): 480–85. http://dx.doi.org/10.4028/www.scientific.net/amm.507.480.
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The development and exploitation of new sources of clean energy that do not depend on traditional sources based on the use of fossil fuels, is the focus of this research, which starts with the optimization of an invention capable of transforming a reciprocating rectilinear motion into continuous circular motion in a very efficient way, to be used in the development of a Wave Energy Converter (WEC), capable of operating with low wave height and taking advantage of the oscillating movement of the waves both when rising, and when lowering, unlike other similar devices that harness it only in one way.
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Andziulis, Arūnas, Jonas Vaupšas, Eleonora Guseinovienė, Rimantas Didžiokas, and Danielius Adomaitis. "EQUIVALENT MECHANICAL PARAMETERS OF OSCILLATING ROTARY MOTORS USED IN TRANSPORT EQUIPMENT." TRANSPORT 21, no. 4 (December 31, 2006): 274–77. http://dx.doi.org/10.3846/16484142.2006.9638078.
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In various appliances and equipment of sundry transport means there is a lot of diverse mechanisms of periodical movement. So, the various piston or membrane pumps of fuel feeding and lubrication systems, circulation pumps, air and refrigerating coolant compressors, etc. are the typical examples of innovative and well promising application of the oscillating motors. In these cases the moving part of a motor can be directly connected to the working body of driven mechanism without the additional gears. Consequently, the drive can be simplified in design and improved in efficiency and reliability. Application of the oscillating rotary motors, if used in the aforesaid devices, strictly depends on specific properties of mechanical system of a motor aggregated with the driven mechanism and considered as the one‐piece unit on the whole. So, this study analyses how the properties of mechanical system, comprised of two moving parts interconnected eccentrically or centrically, can be evaluated by the equivalent rotational inertia, equivalent mass and by equivalent mechanical power factor which, in turn, determine the operating characteristics and basic possibilities of the motor.
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Xue, Gang, Yanjun Liu, Muqun Zhang, and Hongpeng Ding. "Numerical Analysis of Hydrodynamics for Bionic Oscillating Hydrofoil Based on Panel Method." Applied Bionics and Biomechanics 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/6909745.
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The kinematics model based on the Slender-Body theory is proposed from the bionic movement of real fish. The Panel method is applied to the hydrodynamic performance analysis innovatively, with the Gauss-Seidel method to solve the Navier-Stokes equations additionally, to evaluate the flexible deformation of fish in swimming accurately when satisfying the boundary conditions. A physical prototype to mimic the shape of tuna is developed with the revolutionized technology of rapid prototyping manufacturing. The hydrodynamic performance for rigid oscillating hydrofoil is analyzed with the proposed method, and it shows good coherence with the cases analyzed by the commercial softwareFluentand the experimental data from robofish. Furthermore, the hydrodynamic performance of coupled hydrofoil, which consisted of flexible fish body and rigid caudal fin, is analyzed with the proposed method. It shows that the caudal fin has great influence on trailing vortex shedding and the phase angle is the key factor on hydrodynamic performance. It is verified that the shape of trailing vortex is similar to the image of the motion curve at the trailing edge as the assumption of linear vortex plane under the condition of small downwash velocity. The numerical analysis of hydrodynamics for bionic movement based on the Panel method has certain value to reveal the fish swimming mechanism.
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Gao, F., J. G. Lv, and X. C. Zhang. "Design and analysis of a propulsion mechanism using modular umbrella-like wings." Aeronautical Journal 122, no. 1249 (January 14, 2018): 349–68. http://dx.doi.org/10.1017/aer.2017.140.
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ABSTRACTThis article describes the design and evaluation of a new type of propulsion mechanism that uses modular umbrella-like wings oscillating symmetrically in counterphase to generate thrust. The principle of the propulsion and movement of the modular umbrella-like wings was first developed, and the mechanism used to implement the movement of the modular wings was subsequently designed. A structural model and the assembly relationship of the propulsion mechanism were developed for prototype fabrication. An experiment was established to measure the kinematic and mechanical performances of the propulsion mechanism for different reciprocating frequencies and travels. The results for the single umbrella-like wing indicate that either increasing the frequency or enlarging the travel can enhance the average aerodynamic force generated by the wing in one cycle. The results for the modular umbrella-like wings demonstrate that the inertial force generated by the mechanism can be balanced using a symmetrical structure. The average aerodynamic force would be markedly enhanced by increasing the percentage of the time that the outspread wing is moving downwards; e.g. the average aerodynamic force generated by the modular umbrella-like wings was increased by 85.84% compared to the value for a single umbrella-like wing for the same travel and frequency. This work provides practical guidance for optimising the structure design.
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Zhang, M., Yun Huang, and L. Zhang. "Research on the Mechanism of Coordinate Polishing Crankshaft Crankpin with Abrasive Belt." Key Engineering Materials 487 (July 2011): 457–61. http://dx.doi.org/10.4028/www.scientific.net/kem.487.457.
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Under the conditions of crankshaft uniform rotation, the schematic diagram of coordinate polishing crankpin was analyzed and found that the grinding time and speech changed, when the abrasive grinded crankpin. At the same time, the surface roughness was the relevant with the grinding time, grinding for a long time the roughness value was low, grinding time was short then the roughness value was high. In order to ensure that the surface roughness was homogeneity, so that the abrasive grinded the grinding point in the same time, in other words, the abrasive grinded crankpin in the constant velocity. And then the abrasive grinding crankpin was analyzed in the constant velocity, the crankshaft angle was draw the relationship between horizontal displacement and the swing angle. Simultaneity, adopted the level cylinder and the oscillating cylinder mutual moving, that resulted in the mechanism following the rotation of crankshaft back and forth movement, it was due to the weight of mechanism and the lag of the cylinder, and finally the mechanism of lag error was analyzed.
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Ghaemi, Mehrdad, Mina Shojafar, Zahra Zabihinpour, and Yazdan Asgari. "On the possibility of oscillating in the Ebola virus dynamics and investigating the effect of the lifetime of T lymphocytes." PLOS ONE 17, no. 3 (March 11, 2022): e0265065. http://dx.doi.org/10.1371/journal.pone.0265065.
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Ebola virus (EBOV) targets immune cells and tries to inactivate dendritic cells and interferon molecules to continue its replication process. Since EBOV detailed mechanism has not been identified so far, it would be useful to understand the growth and spread of EBOV dynamics based on mathematical methods and simulation approaches. Computational approaches such as Cellular Automata (CA) have the advantage of simplicity over solving complicated differential equations. The spread of Ebola virus in lymph nodes is studied using a simplified Cellular Automata model with only four parameters. In addition to considering healthy and infected cells, this paper also considers T lymphocytes as well as cell movement ability during the simulation in order to investigate different scenarios in the dynamics of an EBOV system. It is shown that the value of the probability of death of T cells affects the number of infected cells significantly in the steady-state. For a special case of parameters set, the system shows oscillating dynamics. The results were in good agreement with an ordinary differential equation-based model which indicated CA method in combination with experimental discoveries could help biologists find out more about the EBOV mechanism and hopefully to control the disease.
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Schillen, Thomas B., and Peter König. "Stimulus-Dependent Assembly Formation of Oscillatory Responses: II. Desynchronization." Neural Computation 3, no. 2 (June 1991): 167–78. http://dx.doi.org/10.1162/neco.1991.3.2.167.
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Recent theoretical and experimental work suggests a temporal structure of neuronal spike activity as a potential mechanism for solving the binding problem in the brain. In particular, recordings from cat visual cortex demonstrate the possibility that stimulus coherency is coded by synchronization of oscillatory neuronal responses. Coding by synchronized oscillatory activity has to avoid bulk synchronization within entire cortical areas. Recent experimental evidence indicates that incoherent stimuli can activate coherently oscillating assemblies of cells that are not synchronized among one another. In this paper we show that appropriately designed excitatory delay connections can support the desynchronization of two-dimensional layers of delayed nonlinear oscillators. Closely following experimental observations, we then present two examples of stimulus-dependent assembly formation in oscillatory layers that employ both synchronizing and desynchronizing delay connections: First, we demonstrate the segregation of oscillatory responses to two overlapping but incoherently moving stimuli. Second, we show that the coherence of movement and location of two stimulus bar segments can be coded by the correlation of oscillatory activity.
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Gasanov, T. G., E. Z. Batmanov, M. R. Guseynov, and M. N. Nazhmudinova. "Determination of dynamic properties of the caterpillar drive of hydraulic reclamation machines and the method of articulated attachment of the working body of the trenchless pipelayer." Herald of Dagestan State Technical University. Technical Sciences 47, no. 4 (January 21, 2021): 122–31. http://dx.doi.org/10.21822/2073-6185-2020-47-4-122-131.
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Objective. The objective of the study is to determine the requirements for various devices of hydraulic reclamation machines, which are widely used in the construction of canals and drains, to maintain a given slope, as well as the calculation of the executive mechanism that serves to eliminate the oscillating movement of the working body relative to the line of the specified slope.Methods. A mathematical description of the vibrations of the working body for caterpillar hydraulic reclamation machines with mounted working bodies is given.Results. The article presents the results of research to identify the main factors affecting the oscillations of the working body of caterpillar reclamation machines. As a result of theoretical and experimental studies, it was found that when a caterpillar machine with a rigid undercarriage crosses single and multiple irregularities, the movement of the cutting edge of the rigidly mounted working body is graphically depicted by sinusoidal curves. The obtained dependencies allow conducting calculations of the automatic system of maintaining the specified slope and establish the area of stable modes of system operation. A geometric method for optimizing the hinge linkage of the working body of trenchless pipelayer is presented.Conclusion. The proposed methods of improving the performance of caterpillar hydraulic reclamation machines with mounted working bodies when moving on uneven ground surfaces can be used to create a wide class of mounted earthmoving machines, both with passive and active working bodies.
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R., Krupych,, Nishchenko, I., Shevchuk, R., and Krupych, S. "Mathematical model of the system “manual vibration shock shaker – fruit branch”." Mehanization and electrification of agricultural, no. 9(108) (2019): 210–23. http://dx.doi.org/10.37204/0131-2189-2019-9-27.
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Purpose. Development of mathematical model of oscillating system “manual vibration shock shaker – fruit branch” for the purpose of theoretical substantiation of the parameters of the shaker. Methods. The basic positions of mathematics, theoretical mechanics, mathematical modeling, program development and numerical calculations on the PC using methods of constructing mathematical models of functioning of agricultural machines are used. Results. The paper proposes a mathematical system model “manual vibration shock shaker – fruit branch” of six differential equations describing the motion of five separate masses (the mass of branch and four masses of individual shaker strings) and differential equations of the transverse and rotational motion of the system as whole. The mathematical system model determines the regularity of the motion of all masses, as well as the reactions of the viscals of the oscillatory system to the impact and after the impact that is generated in the shock mechanism. The proposed nonlinear, complex system of differential equations solves the numerical Runge-Kutta method of the fourth order of accuracy. On the basis of the calculated data the theoretical regularities of change of movement, speed and acceleration of a branch in the place of capture are received, which confirm that in the case of interaction of the cups of the shock mechanism there is blow that is accompanied by an increase in the acceleration of the branch, which is 4–5 times greater than the acceleration of the vibration mode of operation. Conclusions 1. The mathematical model of oscillating system “manual vibration shock shaker – fruit branch” is proposed in the form of system of six differential equations that allows to theoretically substantiate the basic modes of work of the manual shaker in the vibration shock mode to provide the agrotechnical necessary extraction completeness. 2. The received theoretical regularities of change of displacement, speed and acceleration of branch at the place of capture confirm the effectiveness of the vibration shock mode of the shaker. Due to the vibration-shock mode, the acceleration of the branch at the point of transmission of disturbing forces is 4–5 times higher than the acceleration of the vibrational operation mode. Keywords: manual shakes, vibration shocking process, oscillation oscillators, mathematical model, fruit branch, harvesting.
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Ivanov, Ilya, Ivan Pleshcheev, and Andrey Larkin. "Vibratory drilling with digital adaptive control." MATEC Web of Conferences 224 (2018): 01047. http://dx.doi.org/10.1051/matecconf/201822401047.
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High standards and efficiency of deep hole drilling used for hard-to-machine metals and alloys could not be achieved if chips are not segmented in the cutting zone. Chip control could be achieved through transmission of harmonic vibrations to the drill in direction of its rotating axis. One way to maintain these vibrations is to replace a drill chuck with a special self-vibratory drilling head, which includes an elastic element that allows axial movement of the tool. The right stiffness value of an elastic element and appropriate machining conditions could lead to oscillation self-excitation of a drill due to the regenerative mechanism. It is advisable to support this mechanism with a control action defined within the feedback loop, which provides process quality necessary for chip control in the broad range of process parameters. This work analyzes adaptive control algorithm for vibratory drilling process dynamics where control action over an oscillating system is proportional to drill axial vibrational velocity, and a feedback gain is determined in the adaptation loop. Dynamics modeling of a closed-loop nonlinear system “elastic system-machining process-control system” is carried out for cases with or without control proving effectiveness of control algorithm. The model was used to analyze how control system analog-to-digital conversion parameters influence vibratory process quality. Requirements, which ensure control system achieves a control aim, were approximately stated for capacity and response limit for analog-to-digital conversion.
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Шакирова, А. А., П. П. Фирстов, and Р. И. Паровик. "Phenomenological model of the generation of the seismic mode «drumbeats» earthquakes accompanying the eruption of Kizimen volcano in 2011-2012." Вестник КРАУНЦ. Физико-математические науки, no. 4 (December 29, 2020): 86–101. http://dx.doi.org/10.26117/2079-6641-2020-33-4-86-101.
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Извержение вулкана Кизимен в 2011-2012 гг. характеризовалось устойчивым, почти равномерным выжиманием вязкого лавового потока объемом 0.3 км³. Формирование лавового потока сопровождалось возникновением квазипериодических землетрясений режима «drumbeats» с энергетическими классами Ks<7, регистрируемых на длительных временных участках. Показано, что землетрясения генерировались движением фронта вязкого лавового потока, что в практике вулканологических исследований наблюдалось впервые. Предложена феноменологическая модель генерации сейсмического режима «drumbeats». Движение фронта лавового потока по склону вулкана происходило в результате прерывистого скольжения с включением механизма «stick-slip» и возбуждением автоколебательного процесса с генерацией сейсмического режима «drumbeats». Правдоподобность феноменологической модели режима ««drumbeats» на качественном уровне подтверждена математической моделью дробного нелинейного осциллятора. The eruption of the Kizimen volcano in 2011-2012 characterized by stable, almost uniform squeezing of a viscous lava flow with a volume of 0.3 km³. The formation of the lava flow was accompanied by the occurrence of quasiperiodic earthquakes of the “drumbeats” mode with energy classes Ks < 7, recorded at long time intervals. Shown that earthquakes were generated by the movement of the front of a viscous lava flow, which was observed for the first time in the practice of volcanological research. A phenomenological model of “drumbeats” seismic mode generation is proposed. The movement of the front of the lava flow along the slope of the volcano occurred because of intermittent sliding with the inclusion of the «stick-slip» mechanism and the initiation of a self-oscillating process with the generation of a seismic mode «drumbeats». The mathematical model of a fractional nonlinear oscillator qualitatively confirms the plausibility of the phenomenological model of the “drumbeats” mode.
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Samani, Arash E., Jeroen D. M. De Kooning, Nezmin Kayedpour, Narender Singh, and Lieven Vandevelde. "The Impact of Pitch-To-Stall and Pitch-To-Feather Control on the Structural Loads and the Pitch Mechanism of a Wind Turbine." Energies 13, no. 17 (September 1, 2020): 4503. http://dx.doi.org/10.3390/en13174503.
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This article investigates the impact of the pitch-to-stall and pitch-to-feather control concepts on horizontal axis wind turbines (HAWTs) with different blade designs. Pitch-to-feather control is widely used to limit the power output of wind turbines in high wind speed conditions. However, stall control has not been taken forward in the industry because of the low predictability of stalled rotor aerodynamics. Despite this drawback, this article investigates the possible advantages of this control concept when compared to pitch-to-feather control with an emphasis on the control performance and its impact on the pitch mechanism and structural loads. In this study, three HAWTs with different blade designs, i.e., untwisted, stall-regulated, and pitch-regulated blades, are investigated. The control system is validated in both uniform and turbulent wind speed. The results show that pitch-to-stall control enhances the constant power control for wind turbines with untwisted and stall-regulated blade designs. Stall control alleviates the fore-aft tower loading and the blades flapwise moment of the wind turbine with stall-regulated blades in uniform winds. However, in turbulent winds, the flapwise moment increases to a certain extent as compared to pitch-to-feather control. Moreover, pitch-to-stall control considerably reduces the summed blade pitch movement, despite that it increases the risk of surface damage in the rolling bearings due to oscillating movements with a small amplitude.
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Erimaki, Sophia, and Constantinos N. Christakos. "Coherent Motor Unit Rhythms in the 6–10 Hz Range During Time-Varying Voluntary Muscle Contractions: Neural Mechanism and Relation to Rhythmical Motor Control." Journal of Neurophysiology 99, no. 2 (February 2008): 473–83. http://dx.doi.org/10.1152/jn.00341.2007.
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In quasi-sinusoidal (0.5–3.0 Hz) voluntary muscle contractions, we studied the 6- to 10-Hz motor unit (MU) firing synchrony and muscle force oscillation with emphasis on their neural substrate and relation to rhythmical motor control. Our analyses were performed on data from 121 contractions of a finger muscle in 24 human subjects. They demonstrate that coherent 6- to 10-Hz components of MU discharges coexist with carrier components and coherent modulation components underlying the voluntary force variations. The 6- to 10-Hz synchrony has the frequency of the tremor synchrony in steady contractions and is also widespread and in-phase. Its strength ranges from very small to very large (MU/MU coherence >0.50) among contractions; moreover, it is not related to the contraction parameters, in accord with the notion of a distinct 6- to 10-Hz synaptic input to the MUs. Unlike the coherent MU modulations and the voluntary force variations, the in-phase 6- to 10-Hz MU components are suppressed or even eliminated during ischemia, while the respective force component is drastically reduced. These findings agree with the widely assumed supraspinal origin of the MU modulations, but they also strongly suggest a key role for muscle spindle feedback in the generation of the 6- to 10-Hz synaptic input. They therefore provide important information for the study of generators of the 6- to 10-Hz rhythm which subserves the postulated rhythmical control and is manifested as force and movement components. Moreover, they argue for a participation of oscillating spinal stretch reflex loops in the rhythm generation, possibly in interaction with supraspinal oscillators.
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Kyselev, Artem, Lyudmila Blazhko, and Andrey Romanov. "Equivalent conicity and its influence on rolling-stock operation." Proceedings of Petersburg Transport University, no. 2 (June 20, 2017): 247–55. http://dx.doi.org/10.20295/1815-588x-2017-2-247-255.
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Objective: To identify the rolling-stock stability, force reduction, emerging in the process of wheel-rail interaction, the reduction of wheel thread and wheel flange wear, horizontal wear during high-speed running. To consider issues of wheel-rail interaction, that is the influence of a wheel pair equivalent conicity on rolling stock operation. Lateral motion of a wheel pair about an axis of a track in accordance with conicity parameters occurs in the process of standard tapered wheel-rail interaction. Methods: Calculation methods of equivalent conicity and basic assumptions in design diagram were presented. The main functional dependencies of equivalent conicity were determined. “All-purpose mechanism” bundled software, developed on the basis of FastSim algorithm introduced by G. Kalker, was applied for modeling of wheel pair operation on a railway track. Results: Interaction of VNIIZhT-RM-70 wheel for “Sapsan” high-speed trains with R65 rail type was studied, as well as UIC60 rail type used on European railroads. Wheel rolling occurs in different circumferential directions in case of lateral movement of a wheel pair Oscillating motion was described, as well as the parameters on the basis of which equivalent conicity is formed. Practical importance: The necessity in reduction of equivalent conicity to efficiency parameters of high-speed running realization on Russian railroads was revealed by means of modeling.
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Faleh, Muhaimen, Amjad Al-Hamood, and Mahir H. Majeed. "Cam based Infinitely Variable Transmission Theoretic Modelling." IOP Conference Series: Earth and Environmental Science 961, no. 1 (January 1, 2022): 012091. http://dx.doi.org/10.1088/1755-1315/961/1/012091.
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Abstract Infinitely variable transmission (IVT) is a system which delivers the ratio between two turning elements to a continuous (non-discrete) variation (including zero). This article uses Solidworks software to build and simulate a cam-based IVT system. There are two identical units in the system under examination. Each unit comprises a cam with an oscillating slot connection that swings on a hinge and can be vertically shifted by changing the transmission rate. This modifier can be a power screw or a hydraulic ram. In addition, a grooved wheel and followers or an actuator are included in the system units. The raised wheels swing rotating movement, such that they are coupled by a single-way clutch to the output shaft (ratchet) to move the output shaft one way. During the performance research, cam shapes are considered and examined inside the mechanism. a mixture of the unchanging speed and 1-5 polynomial shapes, used for the current investigation and tailored for The results produced from the simulation generally reveal the theoretical results expected in accordance with the layout of the current IVT system. For all parts in these units, the findings imply a uniform velocity while each unit is powered. In this investigation, nevertheless, the ratchets used cause remarkable fluctuations in the angular speed of the output axis. Further research is therefore urgently needed in the choice and investigation of more efficient ratchets.
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Slesarev, Valery I. "Water: a substance with unique properties." Hygiene and sanitation 100, no. 1 (February 12, 2021): 19–24. http://dx.doi.org/10.47470/0016-9900-2021-100-1-19-24.
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Water is a supramolecular aqua system with a single highly structurally dynamic network of hydrogen bonds. Since this grid is inhomogeneous in properties and structure, a proposed aquamezophase model of water takes into account the indicated heterogeneity and homogeneity of water. The peculiarities of intermolecular interactions for hydration and aquaclatratation, characteristic of water, are described. For the first time, the peculiarities of the chemistry and energy of water during vortex motion were revealed. This made it possible to propose a mechanism of action for vortex tubes, a cyclone of J. Rank, and aqua-vortex heat generators. Due to the vortex movement, the aquatic systems of the living organisms actively show restorative properties and become a source of energy necessary for life. Due to the thermodynamic nonequilibrium, openness, nonlinearity, and self-oscillating properties, water is a source of very weak acoustic and electromagnetic aqua emissions in a wide frequency range from fractions of Hz to 1017 Hz, which are recorded as emissions from the end of the 20th century. Since water is a source of radiation and is sensitive to external radiation, water is an aqua-radio system. Under even weak external influences, water is characterized by phase transitions of the second order under external weak influences, at which its ΔUtotal ≈ 0. At the first resonance stage, a quickly coordinated and conjugated transformation |ΔUfree|↔|ΔUconnect| occurs, which changes the properties of water. The second stage is a slow return to its original state, i.e., structural-temporal hysteresis is observed. The change in the properties of water as a result of a phase transition of the second kind is called aquacommunication. Given that living things in molecular composition consist of 99% of water, all living things are also aqua-systems.
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Hasanov, Ramiz, and Musa Kazimov. "Determination of the location of the technological equipment on the chassis of the oil field aggregates." Nafta-Gaz 78, no. 4 (April 2022): 269–73. http://dx.doi.org/10.18668/ng.2022.04.03.
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Currently, it is impossible to imagine the repair and drilling of any well without the use of modern mobile equipment. With technological progress, not only new development technologies in the branch of field exploitation appear, but also new equipment with which oil and gas wells are repaired and reconstructed. Today, oil production is mainly carried out by the operation of wells without a pumping derrick, which makes it possible to sharply reduce the cost of metal and funds. Operations of downhole equipment lifting and tripping in a well are carried out using self-propelled mobile units representing tracked or wheeled transport vehicles on which a derrick (mast) with a winch, transmission and hoisting system is mounted. Lifting units are equipped with a mechanism for raising the mast to the working position and lowering it to the transport position. Installations with a lifting capacity of up to 32 tons inclusive are designed for lifting operations during routine underground repair of wells, whereas over 32 tons minimal lift capacity are required during major repairs and well development. The mobile unit is subjected to oscillatory movements both during transportation along unpaved, semi - destroyed, muddy and snow-covered roads to the well (for development, repair), and during well drilling. The frequency of the oscillating movement depends on the state of the uneven road. The unevenness of the road is expressed by spectral functions. In this case, both the chassis and the body of the mobile unit, as well as the technological equipment located on it, are subjected to oscillatory movements. As a result, technological equipment, as well as devices and equipment located on it, lose their accuracy, which leads to accidents both during drilling and during operation. Therefore, in order to minimize the influence of oscillatory movements on the operability of technological equipment, a technique was developed for technological equipment positioning on the chassis of a mobile unit at an optimal scheme according to the proposed method.
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Zhang, Jin. "Ground Disasters Visual Representation Based on Multi-Field Geospatial Infographics Spectra in Mining Area." Abstracts of the ICA 1 (July 15, 2019): 1–2. http://dx.doi.org/10.5194/ica-abs-1-430-2019.
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<p><strong>Abstract.</strong> Geospatial infographics spectra is a new cross research direction of cartographic theory. It combines the infographic representing geospatial information with the spectra recording spatial-temporal evolution to form geo-infographics spectra, which reflects the characteristics and dynamic changes of the object's morphological structure, mechanism, composition, and reveals the temporal and spatial variation law of regional geo-phenomena. Infographics can be a map in the form of spatial information. It also includes other graphical forms such as images, charts, curves and so on. Spectra is a system established by object characteristics or by time series. Geospatial infographics spectra has the dual characteristics of graphics and genealogy. It is a spatial-temporal composite analysis method that visually represents the spatial morphological structure and spatial-temporal changes of the earth system and its elements and phenomena through graphical thinking and abstract generalization of multi-field geo-digital information.</p><p>From geospatial morphological characteristics, spectrum characteristics, texture characteristics, topographic characteristics, deformation characteristics, structural characteristics, geological environment characteristics, mining characteristics, space-time characteristics, disaster chain characteristics and other dimensions to understand and perspective in depth for geo-disasters in mining areas, to achieve the location-morphology-attribute-semantics-structure-process-relationship of ground disaster based on geo-infographic spectra coupling representation, to construct the geo-disaster environment model expression based on surface functional zoning and geographical grids for mining areas. See Figure 1.</p><p>The spatial morphologies, structure, status, movement, subsidence, stress-strain, etc in the characteristic area of ground hazards is generalized as the basic field (the shape, structure, image information, topography of the hazard body). All the fields that affect the basic field are called effecting field (deformation field, geological structure field, geophysical field, stress field, surface cover field, rainfall field, temperature field, seepage field, soil chemical field, electromagnetic field, etc.). The third is coupled fields, that is scalar or vector fields formed by the coupling of the basic and effecting field (coupling of deformation field and topographic field, deformation field and seepage field, etc.). Based on the 3D mine field model and multi-field information such as basic field, effecting field and coupling field, first we can analyse the time series development stages of stable, oscillating, multi-step, catastrophic, trend-type disasters and then quantitatively segment, partition the types of deformation curves such as V-type, B-type, D-type, R-type pendulum-type and finally set index, discovery pattern and generate geospatial infographics spectra. See Figure 2 and Figure 3.</p><p>A multi-dimensional features-based ground disaster data perception model integrating time, space, semantics and relationships is constructed to realize multi-field information and multi-granularity parsing and location-based information aggregation in disaster feature area. The automatic location information discovery and matching, location semantics association and spatial behaviour inference are accomplished. The spatial behaviour inference under different location semantics is supported to reveal coal mining. It provides precise information support for the impact of the surface and the mechanism of dynamic change. See Figure 3.</p>
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Centeno, G., F. Morales, F. B. Perez, and F. G. Benitez. "Continuous Variable Transmission With an Inertia-Regulating System." Journal of Mechanical Design 132, no. 5 (April 30, 2010). http://dx.doi.org/10.1115/1.4001378.
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This article describes a power transmission system applicable to vehicles. It consists of an oscillating, ratcheting-type, continuously variable transmission (CVT) system governed by an inertia mechanism. The inertia-regulating mechanism adds an additional degree of freedom and gives the system a dynamic character. The transmission consists of three different subsystems. The first of these converts the rotation of the engine or motor into an oscillating angular velocity movement and regulates the amplitude of this movement. The oscillating rotation from the first subsystem is used to drive a second subsystem, which acts as a regulating device by means of an inertial mechanism. The oscillating movement at the output of the second subsystem is rectified in the third, resulting in a unidirectional angular velocity. As a result, a unidirectional torque is generated at the output of the CVT, commensurate with the operating condition of the transmission, and this is capable of overcoming a torque resistance. A prototype of this transmission was built and tested to check the experimental results against those predicted by a series of computational simulations. As a result, the experimental graphs that characterize the operation of this type of transmission system were obtained, demonstrating its ability to function in an efficient manner.
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Burgmann, Sebastian, Michael Dues, Beawer Barwari, Jonas Steinbock, Lars Büttner, Jürgen Czarske, and Uwe Janoske. "Flow measurements in the wake of an adhering and oscillating droplet using laser-Doppler velocity profile sensor." Experiments in Fluids 62, no. 3 (March 2021). http://dx.doi.org/10.1007/s00348-021-03148-0.
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AbstractThe removal of droplets on surfaces by an (air-) flow is relevant, e.g., for cleaning processes or to prevent corrosion or damage of electronic devices. Still the condition for droplet movement is not fully understood. Droplets start to move downstream at a critical (air-) flow velocity vcrit. For increasing flow velocity, this process is related to a strong oscillation of the droplet. This oscillation is supposed to be a key mechanism for the onset of droplet movement in conjunction with the flow field around the droplet. We report on measurements in the wake of the adhering droplet by means of laser-Doppler velocity profile sensor and hot wire anemometry. Thanks to the excellent spatial and temporal resolution of laser-Doppler velocity profile sensor and its capability to measure bidirectional flows, a backflow region can be detected in the wake of the droplet. Therefore, it can be concluded that this backflow structure is the driving mechanism for the strong flow movement inside the droplet against channel flow direction found in previous work. Analyzing the frequency spectra of the flow velocity, it was found that the flow is also oscillating; frequency peaks are in the same range as for the contour oscillation. Based on frequency, diameter and flow velocity, a Strouhal number can be calculated. This Strouhal number is almost constant in the investigated regime of droplet volumes and is between 0.015 and 0.03. Therefore, it can be assumed that an aeroelastic self-excitation effect may be present that eventually leads to droplet movement. Graphic abstract
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VOICU, GHEORGHE, DOREL STOICA, GABRIEL ALEXANDRU CONSTANTIN, CRAITA CARP-CIOCÂRDIA, and ELENA MĂDĂLINA ŞTEFAN. "INFLUENCE OF THE GRANULAR MIXTURE PARTICLES SIZES AND OSCILLATION FREQUENCY ON THE SEPARATION PROCESS AT THE CONICAL SIEVES WITH OSCILLATING MOVEMENT." Journal of Engineering Studies and Research 20, no. 4 (August 19, 2016). http://dx.doi.org/10.29081/jesr.v20i4.57.
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<p>The paper presents the results of experimental researches on the working process and his efficiency for a sieve with external conical surface with alternative periodic motion. The sieve is suspended at the top and bottom with three elastic threads (of silk), with thread diameter f1.5<em> </em>mm and is provided with circular apertures of f4.2<em> </em>mm. Vibratory motion was obtained with an eccentric mechanism, placed horizontally and acting on tangential direction to the sieve at adjustable distance. . Was thus obtained amplitude oscillation of 3.58, 3.74, 3.91 and 4.10 mm. The oscillation frequencies used were 250, 520 and 790 osc/min. The sieve was used for sorting of canola seeds having sizes between f1.25 mm and f2.5 mm, in percent of 95 %.</p><p>It was found that seeds are separated closer to the feeding point of sieve the more so as the oscillation frequency is smaller. Seeds of a size less than 1.5 mm is separated close to the axis of rotation. Also, the sieve orifices can properly calibrate a seeds mix for all oscillation frequencies analyzed.</p>
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Kundrák, Janos, Michael Morgan, Andrii Volodymyrovych Mitsyk, Vladimir Alekseevich Fedorovich, and Anatoliy Ivanovich Grabchenko. "Mathematical simulation of the vibration treatment of parts in a liquefied abrasive working medium." International Journal of Advanced Manufacturing Technology, March 30, 2022. http://dx.doi.org/10.1007/s00170-022-08843-8.
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AbstractThe hydromechanics of the fluidized bed of the processing medium is presented; the conditions for its formation, stability, and the limits of existence are given. The stochasticity of a two-phase hydromechanical process in a fluidized bed has been determined. The boundary conditions on the surface of a spherical processed part and the vibrating machine reservoir surface are considered. It was found that the velocity of granules during collision with the surface of the part, in addition to the chaotic component, has a normal and tangential component. It is established that the amplitude of oscillations of one of the components of the tangential velocity of the part is twice the amplitude of its normal component. The other component of the tangential velocity of the granule at the surface of the part is ten times less than the other components of the velocity. The equations for the dynamics of a fluidized medium are compiled taking into account the nature of the flow around of the part at low Reynolds numbers. The fields of fluid flow near the part are found, and the mechanism of its flow is established. The dynamics of the movement of abrasive granules in a fluidized medium, under the action of the movement of the part, is presented. The dependences of metal removal during vibration treatment of a rotating and oscillating part in a fluidized medium of abrasive granules are obtained. It is shown that metal removal from the processed part depends on the rotation frequency of the part and vibration exciter. It is noted that the presence of granule velocity components at the surface of the part makes it possible to control the processes of work hardening and micro-cutting.