Earthquake Performance of Porcelain Transformer Bushings

2004 ◽  
Vol 20 (1) ◽  
pp. 205-223 ◽  
Author(s):  
Andrew S. Whittaker ◽  
Gregory L. Fenves ◽  
Amir S. J. Gilani
Keyword(s):  
Leakage Current ◽  
Performance Level ◽  
Oil Leakage ◽  
Fundamental Frequencies ◽  
Earthquake Simulator ◽  
Earthquake Performance ◽  
Resonance Search ◽  
Substation Equipment ◽  
High Level

The earthquake performance of 196-kV, 230-kV, and 550-kV porcelain transformer bushings was studied by earthquake-simulator experimentation and analysis. The fundamental frequencies of the 196-kV, 230-kV, and 550-kV bushings were identified to be approximately 15 Hz, 18 Hz, and 8 Hz, respectively, using resonance-search testing on the simulator. The corresponding damping ratios were between 2 and 4 percent of critical. The 196-kV and 230-kV bushings survived severe earthquake shaking and were qualified to the High Level per the IEEE 693-1997 standard. The discrepancy between excellent behavior in the laboratory and poor behavior in the field of these types of bushings calls into question the procedures used for qualification of substation equipment. The 550-kV bushing survived shaking at the moderate performance level with limited damage and minor oil leakage. Current procedures for fragility testing of transformer bushings were evaluated and found to be neither appropriate nor conservative.

Seismic Evaluation and Retrofit of 230-kV Porcelain Transformer Bushings

2001 ◽  
Vol 17 (4) ◽  
pp. 597-616 ◽  
Author(s):  
Amir S. Gilani ◽  
Andrew S. Whittaker ◽  
Gregory L. Fenves
Keyword(s):  
Seismic Performance ◽  
Seismic Evaluation ◽  
General Electric ◽  
Oil Leakage ◽  
Earthquake Simulator ◽  
Rigid Frame ◽  
Moderate Earthquake ◽  
High Level

Static and earthquake-simulator testing of two 230-kV, 3000A, Type-U transformer bushings manufactured in the mid 1980s by the General Electric (GE) Company was undertaken to evaluate both the seismic performance of bushings known to be vulnerable to damage from moderate earthquake shaking, and the efficacy of simple retrofit details. Both bushings survived earthquake shaking compatible with the IEEE spectrum for High Level qualification when mounted on a rigid frame. When mounted on a flexible frame, one 230-kV bushing was unable to sustain the High Level qualification shaking without oil leakage and slip of the porcelain units. Two retrofit details utilizing two semicircular ring plates and epoxy filler were prepared by utility representatives with the objective of limiting slip of the UPPER-1 porcelain unit over the gasket connection. The second detail, Ring-2, permitted the 230-kV bushing to sustain substantially larger accelerations and displacements than those of the unretrofitted bushing and eliminated the permanent slip of the UPPER-1 porcelain unit over the gasket connection for extreme earthquake shaking.

scholarly journals A Wireless System for Monitoring Leakage Current in Electrical Substation Equipment

IEEE Access ◽  
2016 ◽  
Vol 4 ◽  
pp. 2965-2975 ◽  
Author(s):  
N. Harid ◽  
A. C. Bogias ◽  
H. Griffiths ◽  
S. Robson ◽  
A. Haddad
Keyword(s):  
Leakage Current ◽  
Wireless System ◽  
Substation Equipment ◽  
Electrical Substation

Sports Injuries in Team Handball

1998 ◽  
Vol 26 (5) ◽  
pp. 681-687 ◽  
Author(s):  
Romain Seil ◽  
Stefan Rupp ◽  
Siegbert Tempelhof ◽  
Dieter Kohn
Keyword(s):  
Sports Injuries ◽  
Knee Injuries ◽  
Performance Level ◽  
Injury Incidence ◽  
Severe Injuries ◽  
Team Handball ◽  
Severity Of Injury ◽  
And Performance ◽  
High Level ◽  
Level Group

One hundred eighty-six players of 16 teams in 2 male team handball senior divisions were observed prospectively for 1 season to study the injury incidence in relation to exposure in games and practices. Ninety-one injuries were recorded. Injury incidence was evaluated at 2.5 injuries per 1000 player-hours, with a significantly higher incidence in game injuries (14.3 injuries per 1000 game-hours) compared with practice injuries (0.6 injuries per 1000 practice-hours). Practice injury incidence was higher in the lower performance level group, and game injury incidence was higher in the high-level group. The upper extremity was involved in 37% of the injuries, and the lower extremity in 54%. The knee was the most commonly injured joint, followed by the finger, ankle, and shoulder. Knee injuries were the most severe injuries, and they were more frequent in high-level players. There was an increase in the severity of injury with respect to performance level. The injury mechanism revealed a high number of offensive injuries, one-third of them occurring during a counterattack. The injury pattern showed certain variations with respect to player position and performance level. Prophylactic equipment was used by a majority of players at the higher performance level.

scholarly journals Análise da associação do efeito da recepção com os procedimentos de jogo no voleibol de alto nível brasileiro: o caso da equipe campeã da Superliga Feminina

2017 ◽  
Vol 19 (6) ◽  
pp. 663-675 ◽  
Author(s):  
Gustavo De Conti Teixeira Costa ◽  
Mariana Pereira Maia ◽  
Augusto Cézar Rodrigues Rocha ◽  
Leonardo Rodrigues Martins ◽  
Flórence Rosana Faganello Gemente ◽  
...  
Keyword(s):  
Performance Level ◽  
Chi Square ◽  
Chi Square Test ◽  
Spss Software ◽  
High Level ◽  
Women's Volleyball

The present study aimed to analyze the association between effect of reception and game procedures practiced by the women’s “superliga” champion team in the side-out, as well as the behavior of the opposing central blocker, according to the performance level of the opposing team. The sample was composed of the observation of 21 games of the 2015-2016 Women’s “Superliga” champion team. Data were analyzed using the Chi-square test, SPSS software version 20.0 for Windows and significance of p≤0.05. The results showed that there was an association between performance level of the opposing team with the effect of reception (χ2=12.96 and ɸ =0,14, p=0,01), as well the effect of reception with the central blocker disposal (χ2=13.70 and ɸ =0.14, p=0.01), with the attack tempo (χ2=353.27 and ɸ =0.72, p<0.001), with the attack site (χ2=91.05 and ɸ =0.36, p<0.001) and the attack effect (χ2=30.11 and ɸ =0.21, p<0.001) according to the performance level of the opposing team. Together, the results showed that there were differences in the game procedures according to the opposing team classification, contributing to a better understanding of the game played in high-level women’s volleyball.

Leakage current aware high-level estimation for VLSI circuits

2005 ◽  
Vol 152 (6) ◽  
pp. 747
Author(s):  
F. Li ◽  
L. He ◽  
J.M. Basile ◽  
R. Patel ◽  
H. Ramamurthy
Keyword(s):  
Leakage Current ◽  
Vlsi Circuits ◽  
High Level Estimation ◽  
High Level

A HIGH-LEVEL TECHNIQUE FOR ESTIMATION AND OPTIMIZATION OF LEAKAGE POWER FOR FULL ADDER

2013 ◽  
Vol 12 (02) ◽  
pp. 1350011
Author(s):  
JAYRAM SHRIVAS ◽  
SHYAM AKASHE ◽  
NITESH TIWARI
Keyword(s):  
Leakage Current ◽  
Power Supply ◽  
Low Voltage ◽  
Full Adder ◽  
Leakage Power ◽  
Power Gating ◽  
Sleep Transistors ◽  
Power Application ◽  
High Level ◽  
Standby Mode

Optimization of power is a very important issue in low-voltage and low-power application. In this paper, we have proposed power gating technique to reduce leakage current and leakage power of one-bit full adder. In this power gating technique, we use two sleep transistors i.e., PMOS and NMOS. PMOS sleep transistor is inserted between power supply and pull up network. And NMOS sleep transistor is inserted between pull down network and ground terminal. These sleep transistors (PMOS and NMOS) are turned on when the circuit is working in active mode. And sleep transistors (PMOS and NMOS) are turned off when circuit is working in standby mode. We have simulated one-bit full adder and compared with the power gating technique using cadence virtuoso tool in 45 nm technology at 0.7 V at 27°C. By applying this technique, we have reduced leakage current from 2.935 pA to 1.905 pA and leakage power from 25.04μw to 9.233μw. By using this technique, we have reduced leakage power up to 63.12%.

Longer Telomere Length in Elite Master Sprinters: Relationship to Performance and Body Composition

2017 ◽  
Vol 38 (14) ◽  
pp. 1111-1116 ◽  
Author(s):  
Herbert Simoes ◽  
Caio Sousa ◽  
Thiago dos Santos Rosa ◽  
Samuel da Silva Aguiar ◽  
Lysleine Deus ◽  
...  
Keyword(s):  
Telomere Length ◽  
Body Fat ◽  
Healthy Lifestyle ◽  
Significant Negative Correlation ◽  
Performance Level ◽  
Master Athletes ◽  
Actual Performance ◽  
And Performance ◽  
Underlying Mechanisms ◽  
High Level

AbstractEmergent evidence suggests that the long-term healthy lifestyle of master athletes may attenuate aging. We compared telomere length (TL) of high-level master sprinters and non-athlete age-matched controls, and analyzed the relationships of TL with performance and body fat. Elite master sprinters (n=11; aged 50.1±9.2yrs) and healthy untrained controls (n=10; aged 45.4±10.9yrs) had blood samples collected for biochemical and biomolecular analyses. Master sprinters had longer TL, lower body fat and BMI, and a better lipid profile than age-matched controls (p<0.05). A large effect size was verified comparing TL between athletes vs. controls (Cohen’s d=1.039), with a significant negative correlation between TL and performance decline per decade (r=−0.624, p<0.01) and a positive correlation of TL and actual performance level (r=0.641, p<0.01). In conclusion, TL of elite master sprinters was longer than their untrained peers, and seems to be not only a marker of health status, but also an indicator of sports longevity since both actual performance level and its decrease over years were related to TL. Further research might assess the TL of elite master endurance athletes for comparison with sprinters, and also investigate the underlying mechanisms by which the attenuation of telomere shortening occurs in master athletes.

scholarly journals Influence of Game Evolution and the Phase of Competition on Temporal Game Structure in High-Level Table Tennis Tournaments

2017 ◽  
Vol 55 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Jorge Vieira de Mello Leite ◽  
Fabio Augusto Barbieri ◽  
Willian Miyagi ◽  
Elvis de Souza Malta ◽  
Alessandro Moura Zagatto
Keyword(s):  
Phase Analysis ◽  
Olympic Games ◽  
Elite Athletes ◽  
Temporal Structure ◽  
Performance Level ◽  
Previous Literature ◽  
Table Tennis ◽  
Rest Periods ◽  
Rest Time ◽  
High Level

AbstractThe aims of this study were: a) to investigate the game temporal structure in high-level table tennis competitions; b) to verify the influence of game evolution in international competitions from 2009 to 2012 (World Table Tennis Championships and the Olympic Games) on game temporal structure; c) to compare game temporal structure according to the phase of competition. Comparisons between the three international tournaments demonstrated that rally duration decreased significantly (p < 0.05) during the analyzed period (2009-2012), while the rest time increased (p < 0.05) from 2009 to 2011, but decreased (p < 0.05) from 2011 to 2012. In the competition phase analysis, it was found that rally duration decreased (p < 0.05) in the quarterfinals in relation to the semifinals and finals, while the rest time increased (p < 0.05) from the quarterfinals to semifinals and finals. Based on our findings and previous literature, we concluded that the performance level, game evolution and the competition phase influenced the game temporal structure of table tennis, considering longer rest periods adopted by elite athletes in relation to non-elite athletes, the reduction in rally duration and an increase in rest time over the 2009-2012 period and through the competition phases (quarterfinals to finals).

Effect of Performance Level on the Prediction of Middle-Distance-Running Performances Using a Nomogram

2016 ◽  
Vol 11 (5) ◽  
pp. 623-626 ◽  
Author(s):  
Montassar Tabben ◽  
Laurent Bosquet ◽  
Jeremy B. Coquart
Keyword(s):  
High Performance ◽  
Small Difference ◽  
Performance Level ◽  
Distance Running ◽  
Limits Of Agreement ◽  
Running Performance ◽  
Performance Predictions ◽  
High Level ◽  
High Performance Level ◽  
Distance Running Performance

Purpose:This study examined the effect of performance level on the validity and accuracy of middle-distance running-performance predictions obtained from the nomogram of Mercier et al in male runners.Methods:Official French track-running rankings for the 3000-, 5000-, and 10,000-m events from 2006 to 2014 were examined. The performance level was determined from the official reference table of the Fédération Française d’Athlétisme, and the runners were divided in 3 groups (ie, low, moderate, and high levels). Only male runners who performed in the 3 distance events within the same year were included (N = 443). Each performance over any distance was predicted using the nomogram from the 2 other performances.Results:No difference was found in low- and moderate-performance-level athletes (0.02 ≤ effect size [ES] ≤ 0.06, 95% limits of agreement [LoA] ≤ 6%). By contrast, a small difference in high-performance-level athletes (P < .01, 0.23 ≤ ES ≤ 0.45, 95% LoA ≤ 11.6%) was found.Conclusion:The study confirms the validity of the nomogram to predict track-running performance with a high level of accuracy, except for male runners with high performance level (ie, national or international). Consequently, the predictions from the nomogram may be used in training programs (eg, to prescribe tempo runs with realistic training velocities) and competitions (eg, to plan realistic split times to reach the best performance).

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