Updated Review of Stone Matrix Asphalt and Superpave® Projects

2003 ◽  
Vol 1832 (1) ◽  
pp. 217-223 ◽  
Author(s):  
Donald E. Watson
Keyword(s):  
Material Properties ◽  
The United States ◽  
Mix Design ◽  
Stone Matrix Asphalt ◽  
High Traffic Volume ◽  
Long Term Performance ◽  
Term Performance ◽  
Stone Matrix

Stone matrix asphalt (SMA) and Superpave® represent relatively new mix design technologies in the United States. Therefore, a condition survey was conducted of mixes that had been in service for several years to evaluate the long-term performance of SMA and Superpave projects. This study is a follow-up to a 1995 review of SMA projects and a 1998 review of Superpave projects. Both SMA and Superpave are acknowledged to be rut-resistant mixes, and this resistance was shown to be the case during this project review. However, a significant amount of cracking occurred early in the life of some of these mixtures. Overall, the SMA mixtures appeared to be more durable than the Superpave mixtures evaluated. The SMA mixtures have been in place about 2½ years longer than the Superpave mixtures, but the overall condition is about the same. Some of the primary conclusions from the survey are as follows: both SMA and Superpave mixtures were shown to be rut-resistant even when placed on facilities with high traffic volume; much of the observed cracking, especially load cracking, appeared to be more related to problems other than mix design or material properties; and SMA mixtures can be expected to last longer than Superpave mixtures before reaching the same condition level.

Evaluation of Long-Term Performance of Stone Matrix Asphalt in Washington State

2017 ◽  
Vol 31 (1) ◽  
pp. 04016074 ◽  
Author(s):  
Shenghua Wu ◽  
Haifang Wen ◽  
Skyler Chaney ◽  
Kevin Littleton ◽  
Steve Muench
Keyword(s):  
Washington State ◽  
Stone Matrix Asphalt ◽  
Long Term Performance ◽  
Term Performance ◽  
Stone Matrix

Advanced Techniques for Establishing Long-Term Performance of Composite Repair Systems

2014 ◽  
Author(s):  
Chris Alexander
Keyword(s):  
The United States ◽  
Operating Conditions ◽  
Repair System ◽  
Composite Repair ◽  
Design Life ◽  
Repair Systems ◽  
Long Term Performance ◽  
Term Performance ◽  
Composite Repairs

Although composite materials are used to repair and reinforce a variety of anomalies in high pressure transmission gas and liquid pipelines, there continues to be widespread debate regarding what constitutes a long-term composite repair. The United States regulations require that composite repairs must be able to permanently restore the serviceability of the repaired pipeline, while in contrast the Canadian regulations take a more prescriptive approach by integrating the ASME PCC-2 and ISO 24817 composite repair standards along with a requirement for establishing a 50-year design life. In this paper the author provides a framework for what should be considered in qualifying a composite repair system for long-term performance by focusing on the critical technical aspects associated with a sound composite repair. The presentation includes a discussion on establishing an appropriate composite design stress using the existing standards, using full-scale testing to ensure that stresses in the repair do not exceed the designated composite design stresses, and guidance for operators in how to properly integrate their pipeline operating conditions to establish a design life. By implementing the recommendations presented in this paper, operators will be equipped with a resource for objectively evaluating the composite repair systems used to repair their pipeline systems.

Metallurgy and Behavior of Alloys for Reformer Furnaces

2007 ◽  
Author(s):  
Carl E. Jaske
Keyword(s):  
High Temperature ◽  
Material Properties ◽  
Material Behavior ◽  
High Temperature Creep ◽  
Centrifugally Cast ◽  
Resistance To Oxidation ◽  
Long Term Performance ◽  
And Behavior ◽  
Term Performance

This paper reviews the metallurgy and behavior of centrifugally cast heat-resistant alloys for ammonia, methanol, and hydrogen reformer furnaces. The alloys include HK and HP, as well as proprietary versions of these materials produced by various foundries. Alloying and metallurgical factors that affect resistance to oxidation, carburization, and high temperature creep are discussed. Examples of the effects of environment and temperature on material behavior are provided. Finally, the use of material properties to predict the long-term performance of reformer furnace components is reviewed.

Abstract 18854: Long-term Follow-up After Percutaneous Left Atrial Appendage Ligation With the Lariat Device

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Carola Gianni ◽  
Luigi Di Biase ◽  
Sanghamitra Mohanty ◽  
Chintan Trivedi ◽  
Yalçin Gökoglan ◽  
...  
Keyword(s):  
Thromboembolic Event ◽  
Thromboembolic Events ◽  
Long Term Follow Up ◽  
Neurological Event ◽  
Performance Results ◽  
Long Term Performance ◽  
Term Performance ◽  
Retrospective Multicenter Study

Introduction: The objective of this retrospective multicenter study is to report the initial long-term performance results after percutaneous exclusion of the LAA with the endo-epicardial Lariat device to prevent AF-related thromboembolic events. Methods and results: Patients with successful LAA ligation and at least 1-year follow-up were analyzed (N=355). At 1 year, TEE follow-up was present in 172 patients. A leak was defined as presence of flow into the LAA as assessed by TEE. At 6 months, 19 (11%) patients had a leak; 2 strokes occurred: 1 in a patient without a leak and 1 associated with mesenteric ischemia in a patient without a known acute leak, who died before repeat TEE could be performed. At 12 months, 34 (20%) patients had a leak; 6 patients developed a neurological event (5 strokes and 1 TIA), 4 in patients with a leak, 2 in patients without a leak. 3% were followed-up for more than one 1 year (with a mean of 21±9 months). 1 additional thromboembolic event (TIA) occurred 14 months post-implant in a patient without anticoagulation and with a partially excluded LAA (stump), although no leak or thrombus were detected on standard TEE. Among patients with a leak (36% of those with long-term follow-up), 75% were on long-term anticoagulation and no additional TE events were detected. Out of 355 patients, 9 (2.5%) patients had a neurological event: 4 with a leak, 4 without a leak and 1 in a patient where TEE was not repeated. Considering those with known LAA status, thromboembolic events were more common in patients with a leak (4/34 vs 4/136; RR 4, 95% CI 1.1-15.4). Conclusion: In this multicenter experience with the Lariat device, the rate of leaks was high (20% of those with TEE follow-up at 1 year). Thromboembolic events were not rare (overall, 2.5%), and occurred more frequently in patients with a leak (RR 4).

scholarly journals Long-Term Performance and User Satisfaction With Implanted Neuroprostheses for Upright Mobility After Paraplegia: 2- to 14-Year Follow-Up

2018 ◽  
Vol 99 (2) ◽  
pp. 289-298 ◽  
Author(s):  
Ronald J. Triolo ◽  
Stephanie Nogan Bailey ◽  
Kevin M. Foglyano ◽  
Rudi Kobetic ◽  
Lisa M. Lombardo ◽  
...  
Keyword(s):  
User Satisfaction ◽  
Long Term Performance ◽  
Term Performance

scholarly journals Long-Term Results (up to 20 Years) of 19 mm or Smaller Prostheses in the Aortic Position. Does Size Matter? A Propensity-Matched Survival Analysis

2021 ◽  
Vol 10 (10) ◽  
pp. 2055
Author(s):  
Horea Feier ◽  
Andrei Grigorescu ◽  
Lucian Falnita ◽  
Oana Rachita ◽  
Marian Gaspar ◽  
...  
Keyword(s):  
Aortic Root ◽  
Long Term Results ◽  
Original Cohort ◽  
Propensity Matching ◽  
Small Aortic Root ◽  
Long Term Performance ◽  
Term Performance ◽  
Size Matter

Background: The long-term performance of prostheses in the small aortic root is still unclear. Methods: Patients who received a 21 mm or smaller aortic valve between 2000–2018 were retrospectively analyzed. Propensity matching was used in order to account for baseline differences in 19 mm vs. 21 mm valve subgroups. Results: Survival at 10 years was 55.87 ± 5.54% for 19 mm valves vs. 57.17 ± 2.82% for 21 mm ones in the original cohort (p = 0.37), and 58.69 ± 5.61% in 19 mm valve recipients vs. 53.60 ± 5.66% for 21 mm valve subgroups in the matched cohort (p = 0.55). Smaller valves exhibited significantly more patient–prothesis mismatch (PPM) than larger ones (87.30% vs. 57.94%, p < 0.01). All-cause mortality was affected by PPM at 10 years (52.66 ± 3.28% vs. 64.38 ± 3.87%, p = 0.04) in the unmatched population. This difference disappeared, however, after matching: survival at 10 years was 51.82 ± 5.26% in patients with PPM and 63.12 ± 6.43% in patients without PPM. (p = 0.14) Conclusions: There is no survival penalty in using 19 mm prostheses in the small aortic root in the current era. Although PPM is more prevalent in smaller sized valve recipients, this does not translate into reduced survival at 10 years of follow-up.

Doe Progress in Assessing the Long Term Performance of Waste Package Materials

1986 ◽  
Vol 84 ◽  
Author(s):  
A. Berusch ◽  
E. Gause
Keyword(s):  
Site Characterization ◽  
The United States ◽  
High Level Waste ◽  
Design Studies ◽  
Waste Package ◽  
License Application ◽  
High Level ◽  
Long Term Performance ◽  
Term Performance

Summary:Each of the projects has made significant progress toward the eventual operation of a repository for the disposal of high-level radioactive wastes in the United States. Although much has been accomplished, much remains to be done. For example, the Site Characterization Plans for BWIP and NNWSI are nearing completion to be followed by initiation of site characterization activities. The Site Characterization Plan for the selected salt site is scheduled for completion later in 1987. Waste package advanced conceptual design studies are currently scheduled to begin at each project before the end of FY 1987. These efforts will lead to selections of concepts to be detailed in the license application design phase. Compliance with the NRC criteria that require long-term waste package performance will be demonstrated by DOE by performing all of the aforementioned activities. In doing so, the DOE will also be assured that its plan for the safe disposal of high-level waste will be satisfactorily implemented.

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