Repeatability of the Tilt-Table Test Method

1993 ◽  
Author(s):  
C. B. Winkler ◽  
S. E. Bogard ◽  
K. E. Campbell
Author(s):  
Shadi S. Najjar ◽  
Robert B. Gilbert ◽  
Eric A. Liedtke ◽  
Bill McCarron

This paper describes a tilt table test method for measuring the shear resistance between flowlines and supporting soils. This shear resistance is important in considering buckling and walking in the design of flowlines. A significant challenge in measuring the shear resistance is the very low effective normal stresses that exist at the interface in field conditions. Since the measured stresses will be small, even small amounts of friction in a test device can adversely affect the results. The tilt table method overcomes this problem by using gravity to apply the normal and shear stresses to the soil-flowline interface, eliminating the need for a mechanical loading system. A set of test results is presented to demonstrate how the test method can be used to measure the resistance between the flowline and the soil. These results illustrate that the type of flowline coating and the effective normal stress affect the shear resistance.


2015 ◽  
Vol 67 ◽  
pp. S77
Author(s):  
R.K. Gokhroo ◽  
Kumari Priti ◽  
A. Avinash ◽  
Bhanwar Lal Ranwa ◽  
Kamal Kishor ◽  
...  

Author(s):  
Mohammad Reza Khalilian ◽  
Abdolrahim Ghasemi ◽  
Narges Khazaei ◽  
Sara Khoshkhou ◽  
Elham Mahmoudi

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
J M Farinha ◽  
L Parreira ◽  
A F Esteves ◽  
M Fonseca ◽  
A Pinheiro ◽  
...  

Abstract Introduction Reflex syncope is the result of an imbalance between the sympathetic and parasympathetic nervous system. The autonomic nervous system has been associated to some forms of atrial fibrillation (AF). Objective The aim of this study was to assess the prevalence of AF in patients with reflex syncope and a positive tilt table test and to identify the type of tilt test response in patients with AF in comparison to patients without AF. Methods We retrospectively studied consecutive patients that underwent a tilt table test at our institution between 2016 and 2019. We selected those patients with a positive test. Patients with an implanted pacemaker at the time of the tilt test and patients followed in a different institution were excluded. Previous diagnoses of AF episodes were assessed. We analysed the clinical characteristics and the tilt table test results according to previous history of AF. Results We studied 49 patients with a positive tilt test. Seven (14.3%) patients had previously diagnosed paroxysmal AF at the time of the tilt table test. Patients with AF were older, had more frequently hypertension, and the tilt test response was more frequently a vasodepressor than mixed or cardioinhibitory response (71.4% vs. 28.6%) (Table). In univariate analysis, age and hypertension were associated with AF, respectively, OR 1.08 (95% CI 1.01–1.17), p=0.034 and OR 10.80 (95% CI 1.19–98.36), p=0.035. A vasodepressor response was also associated with AF (OR 6.25, 95% CI 1.06–36.74, p=0.043). Conclusions Patients with reflex syncope and a positive tilt table test had a higher prevalence of AF than the general population. A vasodepressor response was associated with AF as were age and hypertension, demonstrating the possible impact of the autonomic nervous system and the multifactorial nature of AF. FUNDunding Acknowledgement Type of funding sources: None.


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