scholarly journals Special characteristics of technical actions, performed by qualified athletes, specializing in 110 m hurdles

2021 ◽  
pp. 33-41
Author(s):  
V.I. Bobrovnick ◽  
S.Ye. Kopanayko
Keyword(s):  
High Speed ◽  
High Performance ◽  
Olympic Games ◽  
Track And Field ◽  
Maximum Speed ◽  
Coordination Ability ◽  
Run Up ◽  
Main Components ◽  
Genetically Determined ◽  
The 19Th Century

The modern high-performance sport is characterized by high sports results, which are shown by athletes at international forums (Olympic Games, World and European Championships). One of the track-and-field athletics events, that can be called unique, is hurdling. The typical characteristics of hurdling include high speed, agility, coordination ability and strength capabilities required to overcome the hurdle. The emergence and development of hurdling began in the second half of the 19th century. The first rules were published in 1864, and the height of the hurdles as well as the distance between them have remained unchanged up to this day. In 1898, in Chicago (USA), A. Kreinzlen set a record in 120 yards hurdles, using a new at that time technique of overcoming hurdles. It was this technique that formed the basis of the modern one and still remains relevant for coaches and athletes [16, p. 29–32, 12, p. 175– 184]. The technical actions of an athlete can be divided into such components as start, starting run-up and distance running. These main components are relevant for both men and women [16, p. 35–37]. The increase of performance rates in hurdling directly depends on learning to overcome obstacles and maintaining the maximum speed along a distance after overcoming, which is the main problem of studying and applying the research results in the training process. Among the main characteristics of hurdlers’ technical actions are the preparation and overcoming of a hurdle (both the first and the following ones along a distance) without losing the possible maximum speed. This means that an athlete must have a highly developed ability to quickly change the elements of technique at a high speed with the help of already developed or genetically determined agility [2, p.199-217]. The analysis of athletes’ performances at the Olympic Games, World and European Championships during 1992 – 2019 showed that nobody among the Ukrainian hurdlers won a prize at these competitions (Table 1).

Olympic competition climbing: the beginning of a new era—a narrative review

2020 ◽  
pp. bjsports-2020-102035
Author(s):  
Christoph Lutter ◽  
Thomas Tischer ◽  
Volker Rainer Schöffl
Keyword(s):  
High Performance ◽  
Olympic Games ◽  
Medical Knowledge ◽  
Maximum Speed ◽  
Prevention Measures ◽  
Injury Rates ◽  
New Era ◽  
Finger Injuries ◽  
Injury Frequency ◽  
Combined Mode

Climbing as a competition sport has become increasingly popular in recent years, particularly the sub-discipline of bouldering. The sport will debut in the Tokyo Summer Olympic Games. National and international competitions have three disciplines: lead (climbing with rope protection), bouldering (climbing at lower heights with mattress floor protection) and speed (maximum speed climbing on a standardised route in 1-on-1 mode). There is also a ‘combined mode’ of all three disciplines (combined) which forms the Olympic competition format; all competition formats are held on artificial walls. Existing literature describes a predominantly low injury frequency and severity in elite climbing. In comparison to climbing on real rock, artificial climbing walls have recently been associated with higher injury rates. Finger injuries such as tenosynovitis, pulley lesions and growth plate injuries are the most common injuries. As finger injuries are sport-specific, medical supervision of climbing athletes requires specific medical knowledge for diagnosis and treatment. There is so far little evidence on effective injury prevention measures in top athletes, and antidoping measures, in general, requiring further work in this field. An improved data situation regarding high-performance climbing athletes is crucial to ensure that the sport continues to be largely safe and injury-free and to prevent doping cases as extensively as possible.

A Power Flow Model for High Speed Motorized Spindles—Heat Generation Characterization

2000 ◽  
Vol 123 (3) ◽  
pp. 494-505 ◽  
Author(s):  
Bernd Bossmanns ◽  
Jay F. Tu
Keyword(s):  
Power Distribution ◽  
High Speed ◽  
High Performance ◽  
Power Flow ◽  
Flow Model ◽  
Maximum Speed ◽  
Motorized Spindle ◽  
Test Procedures ◽  
Source Models ◽  
Motorized Spindles

Lack of a more complete understanding of system characteristics, particularly thermal effects, severely limits the reliability of high speed spindles to support manufacturing. High speed spindles are notorious for their sudden catastrophic failures without alarming signs at high speeds due to thermal problems. In this paper, a qualitative power flow model is presented to characterize the power distribution of a high speed motorized spindle. Quantitative heat source models of the built-in motor and the bearings are then developed. These models are verified with a custom-built high performance motorized spindle of 32 KW and a maximum speed of 25,000 rpm (1.5 million DN). Several systematic test procedures are also developed to validate the models.

Nonlinear Dynamic Behavior of Rotor-Bearing Systems Involving Two Hydrodynamic Oil Films in Series: Prediction and Test Application to High-Speed Turbochargers

2006 ◽  
Author(s):  
Kostandin Gjika ◽  
Chris Groves
Keyword(s):  
Dynamic Behavior ◽  
Nonlinear Dynamic ◽  
High Speed ◽  
High Performance ◽  
Maximum Speed ◽  
Inlet Temperature ◽  
Oil Viscosity ◽  
Rotor Bearing ◽  
Nonlinear Dynamic Behavior ◽  
Bearing System

In recent years, the desire for increased engine performance has led to technology that increasingly relies on robust and reliable turbocharging solutions. The rotor-bearing system (RBS) operates under extreme oil conditions of low viscosity, high temperatures, low HTHS (high temperature high shear) value and low pressure, while the demand for maximum turbocharger speed and variable geometry technology continues to increase. The rotordynamics instability is a potential issue and the development of RBS is becoming a challenge for design optimization at the development stage. It is further complicated by a lack of industrial standards to guide design practices related to the dynamics and the effort to combine high performance with low cost. This paper concerns the progress on nonlinear dynamic behavior modeling of turbocharger rotor-radial bearing system with fully floating bearing design. A developed fluid dynamics code predicts bearing rotational speed, operating inner and outer bearing clearances, effective oil viscosity taking into account the shear effect and hydrostatic load. The data are input to a rotordynamics code which predicts nonlinear lateral response (total shaft motion) of the rotor-bearing system. The model is validated with a high speed turbocharger RBS of 7.9 mm journal diameter running up to 160,000 rpm (maximum speed) with oil 0W30, 100 °C oil inlet temperature and 4 bar oil feed pressure. The test is conducted on a rotordynamics technology cell. An advanced data acquisition system is implanted and a powerful code is developed for automated data reduction. Prediction/test data show good correlation with the respect of synchronous response and total motion. The predictive model helps the development of high performance RBS with faster development cycle times and increased reliability.

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.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

The bright future of digital imaging in scanning electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 768-769
Author(s):  
M. T. Postek ◽  
A. E. Vladar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Digital Imaging ◽  
High Speed ◽  
High Performance ◽  
Mass Storage ◽  
Analog To Digital ◽  
Central Processing ◽  
Digital Imaging Technology ◽  
Scanning Electron

One of the major advancements applied to scanning electron microscopy (SEM) during the past 10 years has been the development and application of digital imaging technology. Advancements in technology, notably the availability of less expensive, high-density memory chips and the development of high speed analog-to-digital converters, mass storage and high performance central processing units have fostered this revolution. Today, most modern SEM instruments have digital electronics as a standard feature. These instruments, generally have 8 bit or 256 gray levels with, at least, 512 × 512 pixel density operating at TV rate. In addition, current slow-scan commercial frame-grabber cards, directly applicable to the SEM, can have upwards of 12-14 bit lateral resolution permitting image acquisition at 4096 × 4096 resolution or greater. The two major categories of SEM systems to which digital technology have been applied are:In the analog SEM system the scan generator is normally operated in an analog manner and the image is displayed in an analog or "slow scan" mode.

Isolation and HPLC Determination of the Chemical Components of Gentianella acuta (Michx.) Hulten

2018 ◽  
Vol 15 (1) ◽  
pp. 21-33
Author(s):  
Ying Wei ◽  
Yongqiao Liu ◽  
Yifan Hele ◽  
Weiwei Sun ◽  
Yang Wang ◽  
...  
Keyword(s):  
Medicinal Plant ◽  
High Speed ◽  
Chemical Constituents ◽  
Folk Medicine ◽  
Gradient Elution ◽  
Chemical Components ◽  
Isolation And Characterization ◽  
Major Chemical ◽  
Main Components ◽  
First Time

Background: Gentianella acuta (Michx.) Hulten is an important type of medicinal plant found in several Chinese provinces. It has been widely used in folk medicine to treat various illnesses. However, there is not enough detailed information about the chemical constituents of this plant or methods for their content determination. Objective: The focus of this work is the isolation and characterization of the major chemical constituents of Gentianella acuta, and developing an analytical method for their determination. Methods: The components of Gentianella acuta were isolated using (1) ethanol extraction and adsorption on macroporous resin. (2) and ethyl acetate extraction and high speed countercurrent chromatography. A HPLC-DAD method was developed using a C18 column and water-acetonitrile as the mobile phase. Based on compound polarities, both isocratic and gradient elution methods were developed. Results: A total of 29 compounds were isolated from this plant, of which 17 compounds were isolated from this genus for the first time. The main components in this plant were found to be xanthones. The HPLC-DAD method was developed and validated for their determination, and found to show good sensitivity and reliability. Conclusion: The results of this work add to the limited body of work available on this important medicinal plant. The findings will be useful for further investigation and development of Gentianella acuta for its valuable medicinal properties.

Performance Analysis of Various Multipliers Using 8T-full Adder with 180nm Technology

2020 ◽  
Vol 13 (6) ◽  
pp. 864-870
Author(s):  
Sai Venkatramana Prasada G.S ◽  
G. Seshikala ◽  
S. Niranjana
Keyword(s):  
Low Power ◽  
Power Dissipation ◽  
High Speed ◽  
High Performance ◽  
Full Adder ◽  
Fundamental Operation ◽  
Wallace Tree ◽  
Power Delay Product ◽  
The Comparative Study ◽  
Wallace Tree Multiplier

Background: This paper presents the comparative study of power dissipation, delay and power delay product (PDP) of different full adders and multiplier designs. Methods: Full adder is the fundamental operation for any processors, DSP architectures and VLSI systems. Here ten different full adder structures were analyzed for their best performance using a Mentor Graphics tool with 180nm technology. Results: From the analysis result high performance full adder is extracted for further higher level designs. 8T full adder exhibits high speed, low power delay and low power delay product and hence it is considered to construct four different multiplier designs, such as Array multiplier, Baugh Wooley multiplier, Braun multiplier and Wallace Tree multiplier. These different structures of multipliers were designed using 8T full adder and simulated using Mentor Graphics tool in a constant W/L aspect ratio. Conclusion: From the analysis, it is concluded that Wallace Tree multiplier is the high speed multiplier but dissipates comparatively high power. Baugh Wooley multiplier dissipates less power but exhibits more time delay and low PDP.

scholarly journals Ultracompact and low-power-consumption silicon thermo-optic switch for high-speed data

Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 937-945
Author(s):  
Ruihuan Zhang ◽  
Yu He ◽  
Yong Zhang ◽  
Shaohua An ◽  
Qingming Zhu ◽  
...  
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
High Speed ◽  
High Performance ◽  
Pulse Amplitude ◽  
Telecommunication Networks ◽  
Low Power Consumption ◽  
Power Efficient ◽  
High Speed Data ◽  
On Chip

AbstractUltracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.

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