Use of parallel polishing technique for root cause determination of EOS devices

2005 ◽  
Author(s):  
W.B. Len ◽  
M. Xue
Keyword(s):  
Root Cause

Investigation of Radiant Superheater Crossover Pipe Weld Cracking at Big Cajun II Station

2002 ◽  
Author(s):  
James P. King ◽  
Robert D. Hendrix
Keyword(s):  
Growth Curves ◽  
Performance Testing ◽  
Circumferential Welds ◽  
Root Cause ◽  
Ultrasonic Time ◽  
History Of ◽  
The Many ◽  
Stress Fatigue ◽  
Ultrasonic Shear

This paper describes the many features of a detailed investigation into the determination of a root cause for internal cracking found in the circumferential welds of radiant superheater crossover piping lines, in the Units No. 1 and 2 boilers at Big Cajun II Station in New Roads, Louisiana. The history of inside diameter, circumferential cracks dates back to 1992. The cracking had been recorded during several outages for both units. It was discovered by use of ultrasonic shear wave testing, and verified by ultrasonic time of flight diffraction methods. During each of the ensuing unit outages, the crack depths were recorded and mapped. Repairs were undertaken by machining out the complete girth weld followed by re-welding. During the interim years cracking did re-occur at many of the weld locations. In 2000, a detailed investigation into the cause of the cracking was initiated, which resulted in recommendations for resolving the ongoing problem. This detailed study included; nondestructive testing and metallurgy of removed metal samples, boiler performance testing and analysis and stress, fatigue and fracture mechanics evaluations. The detailed background, applications and results of the many and varied testing and analytical tasks are fully described herein. The main conclusion to the root cause of the cracking is identified as fatigue caused by the combined effects of thermal and pressure cycles. Recommendations are given which address the actions needed to limit or prevent re-occurrence of the cracking, including revised boiler operating procedures. In addition, a series of fatigue crack growth curves is presented, as a monitoring toot for evaluating existing cracks in the welds.

scholarly journals AN OVERVIEW OF VARIOUS SCALES USED IN CAUSALITY ASSESSMENT OF ADVERSE DRUG REACTIONS

2020 ◽  
pp. 1-5
Author(s):  
ADUSUMILLI PRAMOD KUMAR ◽  
DHARINI BHOOPATHI ◽  
HARIPRIYA SUNKARA ◽  
SRI HARSHA CHALASANI
Keyword(s):  
Adverse Drug Reactions ◽  
Causality Assessment ◽  
Individual Variability ◽  
Drug Reactions ◽  
Root Cause ◽  
Advantages And Disadvantages ◽  
Single Scale ◽  
Relationship Of ◽  
High Possibility

Establishing a relationship of causality between the medications received and the events occurred utilizing causality assessment scale is much needed to reduce the occurrence of Adverse Drug Reactions (ADRs) and to prevent exposure of patients towards additional drug hazards. Causality assessment can be defined as the determination of chance, whether a selected intervention is the root cause of the adverse event observed. The causality assessment is the responsibility of either a single expert or an established committee. As it is a common phenomenon of variable perception of knowledge and experience by each expert, there is a high possibility of disagreement and inter-individual variability on assessment. Many of the causality assessment methods have their advantages and disadvantages. However, no single scale has been adopted as standardized and considered for uniform acceptance.

scholarly journals Root cause determination of on-orbit degradation of the VIIRS rotating telescope assembly

2012 ◽  
Author(s):  
J. D. Barrie ◽  
P. D. Fuqua ◽  
M. J. Meshishnek ◽  
M. R. Ciofalo ◽  
C. T. Chu ◽  
...  
Keyword(s):  
Root Cause

Preserving Evidence for Root Cause Investigations with Halogen-Free Microwave Induced Plasma

2018 ◽  
Author(s):  
C. Odegard ◽  
Andy Burnett ◽  
J. Tang ◽  
J. Wang
Keyword(s):  
Integrated Circuit ◽  
Microwave Induced Plasma ◽  
Root Cause ◽  
Physical Evidence ◽  
Die Surface ◽  
Preservation Of Evidence ◽  
Evidence Gathering ◽  
Customer Returns ◽  
Halogen Free

Abstract Accurate root cause determination of integrated circuit devices necessitates the preservation of evidence during failure analysis. Identifying the cause of systemic defects requires capturing physical evidence provided by very few customer returns. Each piece of physical evidence is valuable due to the scarcity of returns in most cases less than 1 ppm. Harvesting infrequent physical evidence requires that each attempt to decapsulate a fail unit has a high probability of retaining the material that caused the defect. A measured method that retains the critical evidence is the fastest way to solve a defect driven systemic failure mechanism because one gathers the evidence more efficiently. This paper presents two case studies of improved evidence gathering using halogen-free microwave induced plasma (MIP) decapsulation during the root cause investigations. This relatively new method of decapsulation enabled us to preserve evidence, including any changes to the metal and die surface structures along with the presence of contaminants or by-products of failure mechanisms.

Enterprise Tomography

2010 ◽  
pp. 232-251 ◽  
Author(s):  
Jan Aalmink ◽  
Jorge Marx Gómez
Keyword(s):  
Business Processes ◽  
Interdisciplinary Approach ◽  
Semantic Integration ◽  
Specific Domain ◽  
Root Cause ◽  
Business Applications ◽  
Development Organizations ◽  
Dimension Space ◽  
Lifecycle Management

Enterprise tomography is an interdisciplinary approach for an efficient application lifecycle management of enterprise platforms and very large business applications (VLBA). Enterprise tomography semiautomatically identifies and localizes semantic integration concepts and visualizes integration ontologies in semantic genres. Especially delta determination of integration concepts is performed in dimension space and time. Enterprise tomography supports software and data comprehension. SMEs, large scaled development organizations and maintenance organizations can benefit from this new approach. This methodology is useful for tracking database changes of business processes or coding changes within a specific domain. In this way root cause analysis is supported.

Enterprise Tomography

2011 ◽  
pp. 134-153
Author(s):  
Jan Aalmink ◽  
Jorge Marx Gómez
Keyword(s):  
Business Processes ◽  
Interdisciplinary Approach ◽  
Semantic Integration ◽  
Specific Domain ◽  
Root Cause ◽  
Business Applications ◽  
Development Organizations ◽  
Dimension Space ◽  
Lifecycle Management

Enterprise tomography is an interdisciplinary approach for an efficient application lifecycle management of enterprise platforms and very large business applications (VLBA). Enterprise tomography semiautomatically identifies and localizes semantic integration concepts and visualizes integration ontologies in semantic genres. Especially delta determination of integration concepts is performed in dimension space and time. Enterprise tomography supports software and data comprehension. SMEs, large scaled development organizations and maintenance organizations can benefit from this new approach. This methodology is useful for tracking database changes of business processes or coding changes within a specific domain. In this way root cause analysis is supported.

scholarly journals Concrete repair challenges in the Middle East

2019 ◽  
Vol 289 ◽  
pp. 10003
Author(s):  
Rene Brueckner
Keyword(s):  
Middle East ◽  
Root Cause Analysis ◽  
Local Conditions ◽  
Cause Analysis ◽  
Repair Strategy ◽  
Root Cause ◽  
Feasible Solutions ◽  
Document Review

The root cause analysis, determination of the extent of concrete defects and identification of an appropriate repair strategy can be straightforward, but it also often provides significant challenges to both contractors and engineers. The challenges can be due to a lack of QA/QC documentation, locally available investigation equipment, repair material and techniques and accepting actually feasible solutions. The paper presents a case study of a bridge in the Middle East where the root cause analysis was found to be straightforward but the determination of the extent of non-visible defects and the implementation of a feasible repair strategy proved to be much more complicated. The root cause analysis of the defects was carried out by visual inspection, representative intrusive investigations and a comprehensive document review. The determination of the extent of the defects using GPR techniques proved to be challenging under the local conditions. Even more difficulties were encountered by implementing the developed repair strategies to address the various defects to ensure that the required 120 years design life in a very aggressive environment can be achieved. Several revisions to the repair strategy were necessary to identify the most appropriate solution and to accelerate the programme.

Sign in / Sign up

Export Citation Format

Share Document