Safe Operation of DFIG based Wind Parks in Series Compensated Systems

2018 ◽  
Author(s):  
Ulas Karaagac ◽  
Jean Mahseredjian ◽  
Simon Jensen ◽  
Richard Gagnon ◽  
Martin Fecteau ◽  
...  
Keyword(s):  
Safe Operation ◽  
In Series

Towards a Constraint-Based Design of Soft Mechanisms

2016 ◽  
Author(s):  
Sreeshankar Satheeshbabu ◽  
Girish Krishnan
Keyword(s):  
Material Properties ◽  
Building Blocks ◽  
Analysis Framework ◽  
Mobility Analysis ◽  
Safe Operation ◽  
Global Geometry ◽  
In Series ◽  
Cbd Method ◽  
Synthesis Methodology ◽  
Systematic Synthesis

Soft compliant robots and mechanisms have generated great interest due to their adaptability, and inherently safe operation. However, a systematic synthesis methodology for these devices has always remained elusive owing to complexities in geometry, and nonlinearities in deformation and material properties. This paper builds the groundwork towards a constraint based design (CBD) method for a unique class of soft robotic building blocks known as fluid-filled fiber-reinforced elastomer enclosures (FREEs). First, the constraint behavior of FREEs with varying fiber angles is mapped using an automated mobility analysis framework that is based on matrix-based kinetostatic methods. Specifically, such an analysis seeks to establish the constraint behavior of FREEs as a function of not just the global geometry, but also its local anisotropic material constituents. Then, the paper demonstrates the principle of reconfigurable constraint by combining several FREEs in series in accordance to the rules of constraint-based design. Eventual extension to actuating FREEs will enable a comprehensive synthesis methodology for soft robots.

Safe Operation of DFIG-Based Wind Parks in Series-Compensated Systems

2018 ◽  
Vol 33 (2) ◽  
pp. 709-718 ◽  
Author(s):  
Ulas Karaagac ◽  
Jean Mahseredjian ◽  
Simon Jensen ◽  
Richard Gagnon ◽  
Martin Fecteau ◽  
...  
Keyword(s):  
Safe Operation ◽  
In Series

Risk-Based Considerations in Developing Strategies to Ensure Pipeline Integrity—Part II: Applications

1994 ◽  
Vol 116 (3) ◽  
pp. 284-289
Author(s):  
S. Rahman ◽  
B. N. Leis
Keyword(s):  
Probabilistic Models ◽  
Pipe Steel ◽  
Risk Assessments ◽  
Probabilistic Framework ◽  
Safe Operation ◽  
Line Pipe ◽  
Numerical Predictions ◽  
In Series ◽  
Line Pipe Steel ◽  
Developing Strategies

This is the second in series of two papers generated from a recent study on risk-based analysis for developing strategies to ensure pipeline integrity. This paper (Part II—Applications) focuses on the applications of the proposed deterministic and probabilistic models presented in the first paper (Part I—Theory) (Leis and Rahman, 1994) for stochastic pipe fracture evaluations. Using these models, numerical predictions are made for line-pipe steel typically used in gas transmission pipelines and are compared with the available test data. Thereafter, the paper explores the significance of the random variables related to serviceability in pipelines subjected to flaw growth in service. The results are discussed in the light of a hydrotest-based approach to ensure pipeline integrity. It is concluded that analysis of hydrotest strategies to optimize safety for such populations (e.g., Leis and Brust, 1992) should be based on a probabilistic analysis that permits risk assessments associated with pipeline operating decisions and the type and frequency of hydrotests done to ensure continued safe operation of the line. This same probabilistic framework could be used to assess the operating and safety implications for flaw populations characterized by in-line inspection.

scholarly journals Use of Phased Array Ultrasonic Testing For Sizing of Hydrogen Blisters In LPG Wash Water Vessel In INDMAX Unit

2012 ◽  
pp. 203-207
Author(s):  
Mayank Banjare ◽  
Mahendra Pal Pal ◽  
Ch. Nanacharaiah ◽  
V. S. Desai ◽  
Sushil Guria ◽  
...  
Keyword(s):  
Ultrasonic Testing ◽  
Hydrogen Molecule ◽  
Phased Array ◽  
Damage Mechanism ◽  
Wash Water ◽  
Fitness For Purpose ◽  
Hydrogen Atoms ◽  
Safe Operation ◽  
In Series ◽  
Hydrogen Blister

Equipments operating in sour environment containing H2S are prone to deterioration by wet H2S damage mechanism. INDMAX unit (patented FCCU) produces LPG which contains H2S, cyanide as impurities. To remove these impurities LPG is treated with caustic wash and subsequently water wash in series operation. Due to presence of wet H2S environment in the water wash vessel, nascent hydrogen is produced which diffuses in to the wall of the vessel. Due to presence of laminations in the CS shell these hydrogen atoms combined to form hydrogen molecule which exerts severe internal pressure greater than the yield strength of the CS wall inside the laminations resulting in formation of hydrogen blister. This paper describes the use of phased array UT (PAUT) technique for detection of lamination and sizing of hydrogen blisters in the LPG wash water vessel. Fitness for purpose study was carried out for safe operation of this vessel.

The Shikani HME: A New Tracheostomy Heat and Moisture Exchanger

2020 ◽  
Vol 63 (9) ◽  
pp. 2921-2929
Author(s):  
Alan H. Shikani ◽  
Elamin M. Elamin ◽  
Andrew C. Miller
Keyword(s):  
Ex Vivo ◽  
Moisture Loss ◽  
Speaking Valve ◽  
Time Zero ◽  
In Series ◽  
Turbulent Airflow ◽  
The Difference ◽  
Loss Efficiency ◽  
Heat And Moisture ◽  
Lung Simulation

Purpose Tracheostomy patients face many adversities including loss of phonation and essential airway functions including air filtering, warming, and humidification. Heat and moisture exchangers (HMEs) facilitate humidification and filtering of inspired air. The Shikani HME (S-HME) is a novel turbulent airflow HME that may be used in-line with the Shikani Speaking Valve (SSV), allowing for uniquely preserved phonation during humidification. The aims of this study were to (a) compare the airflow resistance ( R airflow ) and humidification efficiency of the S-HME and the Mallinckrodt Tracheolife II tracheostomy HME (M-HME) when dry (time zero) and wet (after 24 hr) and (b) determine if in-line application of the S-HME with a tracheostomy speaking valve significantly increases R airflow over a tracheostomy speaking valve alone (whether SSV or Passy Muir Valve [PMV]). Method A prospective observational ex vivo study was conducted using a pneumotachometer lung simulation unit to measure airflow ( Q ) amplitude and R airflow , as indicated by a pressure drop ( P Drop ) across the device (S-HME, M-HME, SSV + S-HME, and PMV). Additionally, P Drop was studied for the S-HME and M-HME when dry at time zero (T 0 ) and after 24 hr of moisture testing (T 24 ) at Q of 0.5, 1, and 1.5 L/s. Results R airflow was significantly less for the S-HME than M-HME (T 0 and T 24 ). R airflow of the SSV + S-HME in series did not significant increase R airflow over the SSV or PMV alone. Moisture loss efficiency trended toward greater efficiency for the S-HME; however, the difference was not statistically significant. Conclusions The turbulent flow S-HME provides heat and moisture exchange with similar or greater efficacy than the widely used laminar airflow M-HME, but with significantly lower resistance. The S-HME also allows the innovative advantage of in-line use with the SSV, hence allowing concurrent humidification and phonation during application, without having to manipulate either device.

Status of nondestructive control of transport function metal products at JSC EVRAZ NTMK

2020 ◽  
Vol 76 (6) ◽  
pp. 586-590
Author(s):  
S. P. Bersenev ◽  
E. M. Slobtsova
Keyword(s):  
Crack Detection ◽  
Middle Part ◽  
Control Line ◽  
Magnetic Powder ◽  
Nondestructive Control ◽  
Automated Control ◽  
Ultrasonic Control ◽  
Acoustic Contact ◽  
In Series

Achievements in the area of automated ultrasonic control of quality of rails, solid-rolled wheels and tyres, wheels magnetic powder crack detection, carried out at JSC EVRAZ NTMK. The 100% nondestructive control is accomplished by automated control in series at two ultrasonic facilities RWI-01 and four facilities УМКК-1 of magnetic powder control, installed into the exit control line in the wheel-tyre shop. Diagram of location, converters displacement and control operations in the process of control at the facility RWI-01 presented, as well as the structural diagram of the facility УМКК-1. The automated ultrasonic control of rough tyres is made in the tyres control line of the wheel-tyre shop at the facility УКБ-1Д. The facility enables to control internal defects of tyres in radial, axis and circular directions of radiation. Possibilities of the facility УКБ-1Д software were shown. Nondestructive control of railway rails is made at two facilities, comprising the automated control line of the rail and structural shop. The УКР-64Э facility of automated ultrasonic rails control is intended to reveal defects in the area of head, web and middle part of rail foot by pulse echo-method with a immersion acoustic contact. The diagram of rail P65 at the facility УКР-64Э control presented. To reveal defects of the macrostructure in the area of rail head and web by mirror-shadow method, an ultrasonic noncontact electromagnetic-acoustic facility is used. It was noted, that implementation of the 100% nondestructive control into the technology of rolled stuff production enabled to increase the quality of products supplied to customers and to increase their competiveness.

Association between Socioeconomic Factors and Postoperative Complications of Cholecystectomy

2021 ◽  
pp. 1-13
Author(s):  
Herman Romero Ramírez ◽  
Norma Muñoz Albán ◽  
Consuelo Albán Meneses ◽  
Alicia Escobar Torres
Keyword(s):  
Laparoscopic Cholecystectomy ◽  
Postoperative Complications ◽  
Socioeconomic Factors ◽  
Control Variable ◽  
Laparoscopic Technique ◽  
Safe Operation ◽  
Conventional Surgery ◽  
Socioeconomic Characteristics ◽  
Dependent Variables ◽  
Education Levels

The article´s goal isto determine if socioeconomic factors influence the postoperative complications of cholecystectomy. For this, the observational study was defined, analytical and quantitative study was conducted in 100 patients who underwent cholecystectomy. A logistic regression model was applied in which risk factors, socioeconomic characteristics, along with a control variable, were incorporated as variables. Three models were run with alternative dependent variables that are delimited by the type of postoperative complication recorded. The results found showed that women show a higher risk of presenting complications after cholecystectomy, the same occurs in older patients. Likewise, the risk is much lower in people with higher education levels and in patients who underwent laparoscopic cholecystectomy, they only have a 5% risk of presenting complications. Postoperative complications after cholecystectomy are minimized by using the laparoscopic technique and socioeconomic factors would influence the risk of suffering postoperative complications after said surgery, which makes laparoscopic cholecystectomy a safe operation with many other benefits and advantages over traditional or conventional surgery.

Dimensions of plane and solid angles and their units in the International System of Units (SI)

2020 ◽  
pp. 26-32
Author(s):  
M. I. Kalinin ◽  
L. K. Isaev ◽  
F. V. Bulygin
Keyword(s):  
Solid Angle ◽  
International System ◽  
International Committee ◽  
Plane Angle ◽  
Arc Length ◽  
Weights And Measures ◽  
International System Of Units ◽  
System Of Units ◽  
In Series ◽  
Solid Angles

The situation that has developed in the International System of Units (SI) as a result of adopting the recommendation of the International Committee of Weights and Measures (CIPM) in 1980, which proposed to consider plane and solid angles as dimensionless derived quantities, is analyzed. It is shown that the basis for such a solution was a misunderstanding of the mathematical formula relating the arc length of a circle with its radius and corresponding central angle, as well as of the expansions of trigonometric functions in series. From the analysis presented in the article, it follows that a plane angle does not depend on any of the SI quantities and should be assigned to the base quantities, and its unit, the radian, should be added to the base SI units. A solid angle, in this case, turns out to be a derived quantity of a plane angle. Its unit, the steradian, is a coherent derived unit equal to the square radian.

Improving the methods to improve the stability of hydrotechnical structures in Yakutia

2020 ◽  
pp. 37-39
Author(s):  
M LOSKIN
Keyword(s):  
Agricultural Production ◽  
Hydraulic Engineering ◽  
Process Water ◽  
Small Rivers ◽  
Limiting Factor ◽  
Safe Operation ◽  
Central Yakutia ◽  
Agricultural Water Supply ◽  
Temperature Impact ◽  
The Stability

Problems of providing the population and agricultural production by qualitative potable and process water in the Central Yakutia are covered. This territory belongs to the region with acute shortage of water resources which is always a limiting factor of development of agricultural production. For the solution of this burning issue in the 80th years of the last century along the small rivers the systems of hydraulic engineering constructions providing requirements with process water practically of all settlements of the Central Yakutia were constructed. At a construction of all hydraulic engineering buildings the method of construction with preservation of soils of the basis of constructions in a frozen state was applied. When warming the climate which is observed in recent years hydraulic engineering constructions built in regions of a wide spread occurance of breeds of an ice complex and with the considerable volume of water weight, were especially vulnerable. On character and a design they experience continuous threat of damage and demand very attentive relation from the operating organizations. Taking this into account, safe operation of hydraulic engineering constructions in a zone of distribution of permafrost breeds demands new approaches. The article examines features of hydraulic engineering constructions’ operation of agricultural water supply objects in the Central Yakutia. Distinctiveness of hydraulic engineering constructions’ operation is that stability of constructions is intimately bound to temperature impact of a reservoir on ground dams’ body and the basis of constructions. The possibility of inclusion of ways for an intensification of a freezing of constructions in the structure of operational actions is studied. The new method on safe operation of hydraulic engineering constructions as prewinter abatement of the water level in a reservoir accounting volumes and norms of water consumption of the settlement is offered.

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