The dynamic parameters correlation assessment of the textile machine high-speed bearings in changed technological conditions

Measurement ◽  
2018 ◽  
Vol 116 ◽  
pp. 575-585
Author(s):  
Petr Baron ◽  
Marek Kočiško ◽  
Jozef Dobránsky
Keyword(s):  
High Speed ◽  
Dynamic Parameters ◽  
Textile Machine

scholarly journals Research into Correlation between the Lubrication Mode of Contact Surfaces and Dynamic Parameters of Turbo-Generator Transmissions

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Marek Kočiško ◽  
Petr Baron ◽  
Monika Telíšková ◽  
Jozef Török ◽  
Anna Bašistová
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
High Speed ◽  
Oil Quality ◽  
The State ◽  
Dynamic Parameters ◽  
High Frequency Vibration ◽  
Turbo Generator ◽  
Friction Mode ◽  
Contact Surfaces

The paper presents the results of an experimental study aimed at assessing the correlation between the measurement of dynamic parameters (vibration, high-frequency vibration, and acoustic emission) and the analysis of friction mode and the state of lubrication of the contact surfaces of two gearboxes in the turbo-generator assembly (high-speed single-body steam turbine—gearbox—generator) with the transmission power of no more than 50 MW. The analysis confirmed the assumption of a significant correlation of the monitored high-frequency vibration signal with the unsatisfactory engagement of the gear teeth. Through vibration analysis, an increased level of the tooth vibration component and vibration multiples with increased acoustic emission were identified in gearbox operation. The gear oil of one of the gearboxes examined showed a loss of additive elements in the real operation of the contact surfaces of the teeth engagement. The trend analysis confirmed the complexity of the monitored transmission operation in terms of the friction mode and the influence of the oil quality on the state of the tooth flank microgeometry.

scholarly journals How do Reaction Time and Movement Speed Depend on the Complexity of the Task?

2018 ◽  
Vol 2 (69) ◽  
Author(s):  
Dalia Mickevičienė ◽  
Kristina Motiejūnaitė ◽  
Albertas Skurvydas ◽  
Tomas Darbutas ◽  
Diana Karanauskienė
Keyword(s):  
Reaction Time ◽  
High Speed ◽  
Arm Movement ◽  
Movement Speed ◽  
Dynamic Parameters ◽  
Target Movement ◽  
Simple Task ◽  
High Performing ◽  
The Right ◽  
Complicated Task

The aim of the research was to determine how the reaction time and the movement speed depend on the complexity of the task. The research was carried out in the Laboratory of Human Motor Control at the Lithuanian Academy of Physical Education (LAPE) applying the analyzer of dynamic parameters of human leg and arm movement (DPA-1; Patent No. 5251; 2005 08 25), which is used for the qualitative estimation of the dynamic parameters of one arm and leg target movement, two arms and legs coordinated and independent target movements, when the resistance power and target are coded with different programmable parameters. We registered the reaction time (RT) and the movement speed (Vmax) performing simple tasks of reaction and speed and a complicated task of accuracy. Research results indicated that performing a complicated task the reaction is slower, and the maximal movement speed is lower than performing a simple task. However, it does not mean that movement speed will be higher when the reaction is faster performing a simple task. The data obtained confirmed Hick’s law proposing that reaction time is directly proportional to the complexity of the task because performing the tasks of different levels of complexity the reaction time values of the right arm were statistically significantly different (p < 0.001). After performing the analysis of variation coefficients we established that the highest coefficient of variation was received from the indices of movement speed performing a speed task (23%), and the lowest — of reaction time performing a reaction task (10%). The obtained results confirm other authors’ suggestion that performing a complicated task the reaction time is a more steadily controlled index than maximal movement speed. A strong correlation was determined between the reaction time values performing the tasks of reaction and accuracy, but there was no statistical link between the maximal speed values performing the tasks of speed and accuracy. This indicates that if the movement speed is high performing a simple task, it does not mean that it will be high performing a complicated task. Conclusions: 1) performing a complicated task reaction time is longer, and maximal movement speed is lower than performing a simple task; 2) the complexity of the task more impacts the dispersion of results of the movement speed than of the reaction time; 3) high speed performing a simple task does not indicate that it will be high performing a complicated task.Keywords: reaction time, movement speed, the complexity of the task.

scholarly journals NOVEL APPROACH TO EXTRACT DENSE FULL-FIELD DYNAMIC PARAMETERS OF LARGE-SCALE BRIDGES USING SPATIAL SEQUENCE VIDEO

2021 ◽  
Vol 27 (8) ◽  
pp. 617-636
Author(s):  
Guojun Deng ◽  
Zhixiang Zhou ◽  
Shuai Shao ◽  
Xi Chu ◽  
Peng Du
Keyword(s):  
High Speed ◽  
Field Of View ◽  
Mode Shapes ◽  
Main Beam ◽  
Dynamic Parameters ◽  
Full Field ◽  
Damage Location ◽  
Study Results ◽  
Field Dynamic ◽  
Low Order

This study proposes the use of a high-speed camera as a holographic visual sensor to obtain the dense full-field dynamic parameters of the main beam of a bridge by the field of view through uniaxial rotation photography. Based on the basic principle that the frequency and mode of a structure are inherent characteristics, the mode coordinates obtained from each field of view are unified, normalized, and matched according to the same name pixels to obtain the dense fullfield dynamic parameters of the entire bridge. The frequency and first three order modes of a self-anchored suspension test bridge are collected by the method proposed in this study. The frequency comparison between the accelerometers and dial gauges is within 3%, and the mode shapes are more holographic and more realistic than those obtained by limited measuring points. In addition, the difference in the curvature mode under various damage conditions obtained by limited measurement points is compared with that obtained by the method proposed in this study. Results shows that the dense full-field modal curvature difference can reflect the change in the damage location even in a low order, which means the sensitivity of the change of damage location in low-order modal.

Tables of geometric, high-speed and energy characteristics for the bottom parts of a tornado

2018 ◽  
pp. 63-70
Author(s):  
Ирина Юрьевна Крутова
Keyword(s):  
Kinetic Energy ◽  
Rotational Motion ◽  
High Speed ◽  
Natural Phenomenon ◽  
Dynamic Parameters ◽  
Bottom Part ◽  
Energy Characteristics ◽  
Gas Dynamic ◽  
Destruction Zone ◽  
Object Of Study

В настоящей работе при заданном в таблице Фудзиты значении ширины полосы разрушений для всех торнадо установлены два внешних радиуса притока воздуха в придонную часть торнадо: <sub>in</sub><sub>1 </sub> и r<sub>in</sub><sub>2</sub>. Первый из этих радиусов <sub>in</sub><sub>1 </sub> такой, что кинетическая энергия вращательного движения построенного потока составляет половину всей его кинетической энергии. При втором радиусе r<sub>in</sub><sub>2</sub> кинетическая энергия всего потока становится равной кинетической энергии самого слабого торнадо, при котором имеют место разрушения. Знание значений этих радиусов позволит более надежно прогнозировать возникновение торнадо. The natural phenomenon of a tornado, known for its destructive power, is an object of study of many scientists. The available part of the data of field observations of this natural phenomenon is systematized and collected in the so-called Fujita scale. In particular, it indicates the width of the fracture band for tornadoes of different intensity, and only the values of the maximum wind speed are given from the gas dynamic parameters. Bautin S.P. proposed and justified the scheme of occurrence and functioning of natural ascending swirling flows of the tornado and tropical cyclones. Based on both this scheme and the data of the Fujita scale, the external radii of air inflow in the near-bottom parts of tornadoes of various intensities are established and the gas dynamic parameters of these flows are calculated. It turned out that in the case of the lowest intensity from the Fujita scale, the kinetic energy of the rotational motion of the air is half of the entire kinetic energy of the flow in the bottom part. As tornado intensity increases, the kinetic energy of rotational motion becomes the more prominent part of the total kinetic energy of the flow. In this paper, given the Fujita value of the width of the destruction zone for all tornadoes along with the two external radii of air inflow into the bottom part of the tornado are established as r<sub>in</sub><sub>1 </sub> and r<sub>in</sub><sub>2</sub>. The first of these radii, namely r<sub>in</sub><sub>1 </sub>, denotes the radius at which the kinetic energy of the rotational motion of the constructed stream is half of all the kinetic energy of this stream. The second one denoted as r<sub>in</sub><sub>2</sub>, is the radius at which the kinetic energy of the entire stream becomes equal to the kinetic energy of the weakest destructive tornado. Knowing the values of these radii allows reliable predicting the origin of the tornado.

Coulomb Friction and Optimal Rocker Arm Ratio for High-Speed Cam Systems

1986 ◽  
Vol 108 (3) ◽  
pp. 340-344 ◽  
Author(s):  
A. P. Pisano ◽  
Hong Tao Chen
Keyword(s):  
Coulomb Friction ◽  
High Speed ◽  
Dynamic Parameter ◽  
Kinematic Parameter ◽  
Operating Speed ◽  
Dynamic Parameters ◽  
Lumped Model ◽  
Design Charts ◽  
Local Extrema ◽  
Cam Systems

The operating speed of a high-speed cam system can be maximized by the proper choice of both kinematic and dynamic parameters of a lumped model. Considering rocker arm ratio as an unconstrained kinematic parameter and Coulomb friction as an unconstrained dynamic parameter, it was found that the camshaft speed at which toss occurred was characterized by several local extrema, all of which were sensitive to the presence of Coulomb friction. For a particular cam system and two separate cam lift curves, design charts have been developed to aid in the choice of optimal rocker arm ratio for maximum operating speed in the presence of Coulomb friction.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

Vacuum System to Minimize the Specimen Contamination of High-Performance EM

1977 ◽  
Vol 35 ◽  
pp. 68-69
Author(s):  
N. Yoshimura ◽  
K. Shirota ◽  
T. Etoh
Keyword(s):  
Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
High Vacuum ◽  
Vacuum System ◽  
Pump System ◽  
Pumping System ◽  
Diffusion Pump ◽  
Almost All ◽  
Cascade Type

One of the most important requirements for a high-performance EM, especially an analytical EM using a fine beam probe, is to prevent specimen contamination by providing a clean high vacuum in the vicinity of the specimen. However, in almost all commercial EMs, the pressure in the vicinity of the specimen under observation is usually more than ten times higher than the pressure measured at the punping line. The EM column inevitably requires the use of greased Viton O-rings for fine movement, and specimens and films need to be exchanged frequently and several attachments may also be exchanged. For these reasons, a high speed pumping system, as well as a clean vacuum system, is now required. A newly developed electron microscope, the JEM-100CX features clean high vacuum in the vicinity of the specimen, realized by the use of a CASCADE type diffusion pump system which has been essentially improved over its predeces- sorD employed on the JEM-100C.

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