A Successful Strategy for Managing the Mechanical Integrity of Coke Drums

2017 ◽  
Author(s):  
Pierre Du Plessis ◽  
Mahmod Samman
Keyword(s):  
Fatigue Test ◽  
Old Age ◽  
Test Program ◽  
Successful Strategy ◽  
Mechanical Integrity ◽  
Thin Walls ◽  
Novel Approach

A novel approach to mechanical integrity was utilized for addressing failures in an old set of coke drums. Using a rigorous routine of inspections, assessments, and long-term repairs, drums which had suffered accelerated deterioration, unpredicted cracks, and loss of containment were transformed to a reliable set of vessels. Despite old age and thin walls, due to the success of this strategy and results of a fatigue test program, plans to replace these vessels were canceled and the time between turnarounds is being considered for an increase. In this paper, we describe the approach that was used and compare results from this set of drums to another set at the same facility that was managed differently.

Charlemagne’s Health in ‘Old Age’: Did It Affect Carolingian Military Strategy?

Mediaevistik ◽  
2020 ◽  
Vol 32 (1) ◽  
pp. 11-53
Author(s):  
Bernard S. Bachrach
Keyword(s):  
Old Age ◽  
The Political ◽  
Military Strategy ◽  
The West ◽  
Long Time

During the first thirty-three years of his reign as king of the Franks, i.e., prior to his coronation as emperor on Christmas day 800, Charlemagne, scholars generally agree, pursued a successful long-term offensive and expansionist strategy. This strategy was aimed at conquering large swaths of erstwhile imperial territory in the west and bringing under Carolingian rule a wide variety of peoples, who either themselves or their regional predecessors previously had not been subject to Frankish regnum.1 For a very long time, scholars took the position that Charlemagne continued to pursue this expansionist strategy throughout the imperial years, i.e., from his coronation on Christmas Day 800 until his final illness in later January 814. For example, Louis Halphen observed: “comme empereur, Charles poursuit, sans plus, l’oeuvre entamée avant l’an 800.”2 F. L. Ganshof, who also wrote several studies treating Charlemagne’s army, was in lock step with Halphen and observed: “As emperor, Charlemagne pursued the political and military course he had been following before 25 December 800.”3

Development of a Performance-Related Framework for Asphalt Mixture Design for the Illinois Tollway

2021 ◽  
pp. 036119812110148
Author(s):  
Behnam Jahangiri ◽  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
William G. Buttlar
Keyword(s):  
Asphalt Mixture ◽  
Field Performance ◽  
Compact Tension ◽  
T Test ◽  
Novel Approach ◽  
Final Adjustment ◽  
Development And Validation ◽  
High Degree ◽  
Selection Of

Various agencies have begun to research and introduce performance-related specifications (PRS) for the design of modern asphalt paving mixtures. The focus of most recent studies has been directed toward simplified cracking test development and evaluation. In some cases, development and validation of PRS has been performed, building on these new tests, often by comparison of test values to accelerated pavement test studies and/or to limited field data. This study describes the findings of a comprehensive research project conducted at Illinois Tollway, leading to a PRS for the design of mainline and shoulder asphalt mixtures. A novel approach was developed, involving the systematic establishment of specification requirements based on: 1) selection of baseline values based on minimally acceptable field performance thresholds; 2) elevation of thresholds to account for differences between short-term lab aging and expected long-term field aging; 3) further elevation of thresholds to account for variability in lab testing, plus variability in the testing of field cores; and 4) final adjustment and rounding of thresholds based on a consensus process. After a thorough evaluation of different candidate cracking tests in the course of the project, the Disk-shaped Compact Tension—DC(T)—test was chosen to be retained in the Illinois Tollway PRS and to be presented in this study for the design of crack-resistant mixtures. The DC(T) test was selected because of its high degree of correlation with field results and its excellent repeatability. Tailored Hamburg rut depth and stripping inflection point thresholds were also established for mainline and shoulder mixes.

A Novel Approach Towards Cementing Design Achieved Significant Improvement in Long Term Zonal Isolation

2019 ◽  
Author(s):  
Ala Suleiman ◽  
Bashar Hilal ◽  
Phalgun Paila ◽  
Sahir Abdelhadi ◽  
Khalid Alwahedi ◽  
...  
Keyword(s):  
Novel Approach ◽  
Zonal Isolation

Stabilisation of Hg1-xCdxTe:Hg1-yCdyTex ≠ y) Heterointerfaces and Applications in Infra Red Devices

1990 ◽  
Vol 216 ◽  
Author(s):  
Paul A. Clifton ◽  
Paul D. Brown
Keyword(s):  
Barrier Layer ◽  
Epitaxial Layers ◽  
Long Wavelength ◽  
Long Term Stability ◽  
Novel Approach ◽  
Infra Red ◽  
Passivation Layers ◽  
Cdte Buffer ◽  
Initial Results

ABSTRACTThe interface between Hg1-xCdxTe(0 ≦ x ≦ 1) and Hg1-yCdyTe(0 ≦ y ≦ 1) epitaxial layers of different composition (x ≠ y) is unstable with regard to the intermixing of the Hg and Cd cations within the Group II sublattice. This phenomenon may give rise to long-term stability problems in HgTe-(Hg,Cd)Te superlattices and composition grading between (Hg,Cd)Te absorber layers and CdTe buffer or passivation layers in epitaxial infra red detectors. In this paper, a novel approach to the inhibition of interdiffusion in these systems is discussed. This involves the growth of an intervening ZnTe barrier layer at the heterointerface between two (Hg,Cd)Te layers. Initial results are presented which indicate the effectiveness of this technique in reducing interdiffusion in an experimental heterostructure grown by MOVPE. Some possible applications in a variety of HgTe-based long wavelength devices are discussed.

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