scholarly journals Effect of the Gravel Zone Thickness Created in the Deep Well Test Simulation on the Operating Characteristics of the Pump and Head Loss

Teknik Dergi ◽  
2021 ◽  
Author(s):  
Nuri ORHAN ◽  
Osman ÖZBEK ◽  
Ali Yavuz ŞEFLEK
Keyword(s):  
Head Loss ◽  
Well Test ◽  
Operating Characteristics ◽  
Deep Well

Casing Wear Influence Factors and Range Analysis

2014 ◽  
Vol 687-691 ◽  
pp. 220-223 ◽  
Author(s):  
Xin He Wang ◽  
Shao Bo Wei ◽  
Xiao Zeng Wang ◽  
Yang Yu ◽  
Yi Hua Dou
Keyword(s):  
Contact Force ◽  
Orthogonal Experiment ◽  
Influence Factors ◽  
Steel Grade ◽  
Well Test ◽  
Range Analysis ◽  
Rotating Speed ◽  
Deep Well ◽  
Drilling Parameters ◽  
Casing Wear

In the deep and ultra deep well casing wear is serious. The decrease of strength leads to casing damage, affects the follow-up well test and completion. In order to analyze the influence of the contact force, rotating speed, steel grade and muds on casing wear, determine the optimized level collocation scheme which makes casing wear minimum, optimize drilling parameters and casing programs, reduce casing wear, four factors and three levels orthogonal experiment of casing wear was carried out, and the range analysis of the experiment results is made. The results show that the best match of factors is A1B1C1D3, namely when the contact force is 200 N(A1), rotating speed 60 r/min (B1), steel grade N80(C1), oil-based mud (D3) casing wear is minimal. The influence of muds on casing wear is the largest, the next is casing steel grade, and then rotating speed, the effect of the contact force minimal. The improvement of mud performance is best method to reduce casing wear.

Optimal Power Distribution among Hydropower Units Taking into Account Head Loss in Units’ Trash Screens

2014 ◽  
Vol 698 ◽  
pp. 774-779 ◽  
Author(s):  
Gleb Glazyrin ◽  
Nikolay Tverdokhlebov ◽  
Yury Kazantsev
Keyword(s):  
Power Distribution ◽  
Renewable Energy Sources ◽  
Power Production ◽  
Head Loss ◽  
Hydropower Plant ◽  
Operating Characteristics ◽  
Actual Performance ◽  
Optimal Power ◽  
Performance Specifications ◽  
Necessary And Sufficient

As is known, the importance of renewable energy sources is rapidly growing. The paper addresses one of the important issues paying attention to the optimization of hydropower plant units’ regimens. Considering the unit operating characteristics as unequal at different head levels, the authors propose to take into account the real head of water column for each unit to define the actual performance specifications. Further, this information can be utilized in the optimization process to minimize water expenditure at hydropower plant. The authors have derived the objective function and the restrictions related to the process of real power production. Then, they have proposed a new optimization algorithm instead of traditional ones, assuming that it has advantages in speed and simplicity. The block diagrams of the proposed algorithm as well as the necessary and sufficient explanations have been presented. As a final point, the results of conducted tests and conclusion indicate that the algorithm solves the problem satisfactorily. It could be integrated into the group power control system to perform operations at a hydropower plant in an effective way.

Kriteriumsbezogene Cut-Off-Werte für Tätigkeitsspielraum und Arbeitsintensität

Diagnostica ◽  
2019 ◽  
Vol 65 (3) ◽  
pp. 179-190 ◽  
Author(s):  
Vincent Mustapha ◽  
Renate Rau
Keyword(s):  
Receiver Operating Characteristics ◽  
Operating Characteristics ◽  
Receiver Operating

Zusammenfassung. Cut-Off-Werte ermöglichen eine ökonomische, binäre Beurteilung von Summenscores. Für Beanspruchungsfragebögen, die personenbezogene Merkmale erfragen, sind Cut-Off-Werte häufig vorhanden und in der klinischen Diagnostik unerlässlich. Für die Bewertung von Arbeitsmerkmalen sind Cut-Off-Werte ebenfalls wünschenswert. Bislang fehlen sie jedoch für die Beurteilung von Arbeitsmerkmalen wie Arbeitsintensität und Tätigkeitsspielraum. Zwischen 2006 und 2016 wurden daher in verschiedenen Branchen 801 objektive Arbeitsplatzanalysen durchgeführt, welche eine Unterteilung in gut und schlecht gestalteten Tätigkeitsspielraum sowie gut und schlecht gestaltete Arbeitsintensität nach DIN EN ISO 6385 (2016) ermöglichen. Anhand dieser Unterteilung wurden mit der Receiver-Operating-Characteristics-Analyse Cut-Off-Werte für den subjektiv-bedingungsbezogen Fragebogen zum Erleben von Arbeitsintensität und Tätigkeitsspielraum (FIT; Richter et al., 2000 ) ermittelt. Für den Tätigkeitsspielraum weisen Summenscores ≤ 22 und für die Arbeitsintensität Summenscores ≥ 15 auf eine schlechte Gestaltung des jeweiligen Arbeitsmerkmals hin. Anhand einer weiteren Stichprobe von 1 076 Arbeitenden konnte gezeigt werden, dass Arbeitende mit schlecht gestaltetem Tätigkeitspielraum vital erschöpfter sowie weniger engagiert sind und Arbeitende mit schlecht gestalteter Arbeitsintensität eine höhere Erholungsunfähigkeit sowie vitale Erschöpfung aufweisen.

Operating characteristics of unit and group connected generator-HVDC converter schemes

1993 ◽  
Vol 140 (6) ◽  
pp. 503 ◽  
Author(s):  
J. Arrillaga ◽  
J.R. Camacho ◽  
S.J. MacDonald ◽  
C.P. Arnold
Keyword(s):  
Operating Characteristics

Ram accelerator operating characteristics at elevated fill pressures

2000 ◽  
Vol 10 (PR11) ◽  
pp. Pr11-11-Pr11-21 ◽  
Author(s):  
C. Bundy ◽  
C. Knowlen ◽  
A. P. Bruckner
Keyword(s):  
Operating Characteristics ◽  
Ram Accelerator

ROC Analysis of Three Perfusion Display Options for ECG-gated Perfusion SPECT in Severe CAD

1999 ◽  
Vol 38 (06) ◽  
pp. 172-177
Author(s):  
H. Bailer ◽  
Marianne Gwechenberger ◽  
Martha Pruckmayer ◽  
A. Staudenherz ◽  
G. Kronik ◽  
...  
Keyword(s):  
Roc Analysis ◽  
Lateral Wall ◽  
Visual Assessment ◽  
3D Mapping ◽  
Operating Characteristics ◽  
Gated Perfusion Spect ◽  
Perfusion Spect ◽  
Coronary Stenoses ◽  
Definition Of ◽  
Valve Plane

Summary Aim: The simultaneous computation and display of wall motion and perfusion patterns in a single 3D ventricular model would considerably ease the assessment of ECG-gated Tc-99m-sestamibi SPECT, yet the effect on the accuracy of allocating regional perfusion has so far not been validated. Methods: 3D perfusion mapping (3D Perfusion/Motion Map Software) was compared to the visual assessment of ungated tomographic slices and polar perfusion mapping (Cedars-Sinai PTQ) by correlation analysis and receiver operating characteristics (ROC) analysis at different cut-off levels for coronary stenoses in 50 patients (11 single-, 22 two-, 16 three-vessel disease). Ungated SPECT data were obtained by adding the intervals prior to reconstruction and displaying conventional tomographic slices. All display options were visually assessed in 8 ventricular segments according to a 4-point scoring system and compared to the graded results of coronary angiography. Results: All three display options showed a comparable diagnostic performance for the detection of severe stenoses. The diagnostic gain for the detection of stenoses above 59% was highest for ungated tomographic slices, followed by ungated polar mapping and 3D mapping. Regional assessment revealed a limited performance of 3D mapping in the proximal anterior and distal lateral wall. Polar mapping showed a balanced regional performance. Conclusion: 3D Perfusion mapping provides comparable information to conventional display options with the highest diagnostic strength in severe stenoses. Further improvement of the algorithm is needed in the definition of the valve plane.

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