Influence of Temperature and Carbon-Dioxide Pressure on the Corrosion and Stress-Corrosion Fracture of Pipe Steels in Model Stratal Water

2021 ◽  
Author(s):  
V. А. Vynar ◽  
Kh. B. Vasyliv ◽  
N. B. Ratska ◽  
V. R. Ivashkiv ◽  
M. R. Chuchman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Stress Corrosion ◽  
Pipe Steels ◽  
Stratal Water ◽  
Influence Of Temperature ◽  
Corrosion Fracture ◽  
Carbon Dioxide Pressure

Forecasting of pipe steels service life during operation in presence of hydrogen sulfide and carbon dioxide

2021 ◽  
pp. 469-476
Author(s):  
S.Yu. Kondrat'ev ◽  
A.A. Al'khimenko ◽  
A.A. Khar'kov ◽  
O.V. Shvetsov ◽  
A.D. Davydov
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Deformation Rate ◽  
Loading Rate ◽  
Corrosion Cracking ◽  
Corrosive Environment ◽  
Pipe Steels ◽  
Accelerated Tests

The effect of the loading rate and temperature on the damage of pipe steels in environments containing hydrogen sulfide and carbon dioxide is studied. The results of accelerated tests at slow deformation rate for the resistance of steels to stress corrosion cracking are analyzed. The deformation rate is justified for conducting reliable tests for stress corrosion cracking and temperature effect on pipe steels is revealed. The criteria for the tendency assessing of pipe steels to stress corrosion cracking in accelerated tests are the fracture stress or the ratio of stresses in corrosive environment and in air and the elongation or the ratio of elongations in corrosive environment and in air.

Exercise end-tidal carbon dioxide pressure: a new prognostic marker after acute myocardial infarction?

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
J Ferreira ◽  
P Rio ◽  
A Castelo ◽  
I Cardoso ◽  
S Silva ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Carbon Dioxide ◽  
Acute Myocardial Infarction ◽  
Prognostic Marker ◽  
Systolic Function ◽  
Prognostic Role ◽  
End Tidal Carbon Dioxide ◽  
Carbon Dioxide Pressure ◽  
End Tidal ◽  
Maximal Effort

Abstract Funding Acknowledgements Type of funding sources: None. Background Although several cardiopulmonary exercise testing (CPET) parameters have already proved to predict prognosis, there is increasing interest in finding variables that do not require maximal effort. End-tidal carbon dioxide pressure (PETCO2), an indirect indicator of cardiac output, is one of such variables. Studies in heart failure populations already suggest its role as a prognostic factor. However, data concerning other populations are still scarce. Purpose To assess the association between exercise PETCO2, cardiac biomarkers and systolic function following acute myocardial infarction (AMI) and to evaluate its potential prognostic role in this population. Methods A retrospective single-centre analysis was conducted including patients who underwent symptom-limited CPET early after AMI. We assessed PETCO2 at baseline (PETCO2-B), at anaerobic threshold (PETCO2-AT) and at peak exercise and calculated the difference between PETCO2-AT and PETCO2-B (PETCO2-difference). We analysed their association with B-natriuretic peptide (BNP), maximal troponin after AMI as well as with left ventricular ejection fraction (LVEF) 1 year after. Results We included 40 patients with a mean age of 56 years (87.5% male), assessed with CPET a median of 3 months after AMI (80% of which were ST-elevation myocardial infarctions). Average respiratory exchange ratio was 1,1 with 48% of patients not reaching maximal effort. Mean PETCO2-AT was 37mmHg, with a mean increase from baseline of 6mmHg (PETCO2-difference). There was a significant positive correlation between all the PETCO2 variables measured and BNP values at time of AMI and on follow-up (best correlation for PETCO2-AT with BNP at AMI hospitalization, r = 0.608, p < 0.001). Maximal troponin was not correlated with PETCO2. Both PETCO2-AT and PETCO2-difference were significantly and positively correlated with LVEF 1-year post-AMI (r = 0.421, p = 0.040 and r = 0.511, p = 0.011, respectively). Conclusion PETCO2-AT and PETCO2-difference are both correlated with BNP, an established prognostic marker, and with medium-term systolic function after AMI, suggesting their potential prognostic role in this population. Further studies with larger samples are required to confirm the results of this pilot study and assess PETCO2 as a definite predictor of prognosis after AMI.

scholarly journals Erratum to: Initiation of Stress Corrosion Cracks in X80 and X100 Pipe Steels in Near-Neutral pH Environment

2016 ◽  
Vol 25 (8) ◽  
pp. 3546-3547
Author(s):  
Jidong Kang ◽  
Wenyue Zheng ◽  
Darren Bibby ◽  
Babak Shalchi Amirkhiz ◽  
Jian Li
Keyword(s):  
Stress Corrosion ◽  
Pipe Steels ◽  
Neutral Ph

Effect of CO2 and 100% O2 on cerebral blood flow in preterm infants

1980 ◽  
Vol 48 (3) ◽  
pp. 468-472 ◽  
Author(s):  
F. A. Leahy ◽  
D. Cates ◽  
M. MacCallum ◽  
H. Rigatto
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Preterm Infants ◽  
Cerebral Circulation ◽  
Pressure Change ◽  
Venous Occlusion ◽  
Co2 Sensitivity ◽  
Important Regulator ◽  
Carbon Dioxide Pressure

To determine 1) the effect of arterial CO2 change on the neonatal cerebral circulation and 2) whether 100% O2 would produce significant decrease in cerebral blood flow (CBF), we studied 24 preterm infants to explain the late (5 min) hyperventilation observed in them during hyperoxia. Of these, 12 were studied before and during inhalation of 2-3% CO2 and 12 before and during the inhalation of 100% O2. We measured CBF by a modification of the venous occlusion plethysmography technique and found that CBF increased 7.8% per Torr alveolar carbon dioxide pressure change and that it decreased 15% with 100% O2. These findings suggest that 1) CO2 is an important regulator of CBF in the perterm infant, 2) CBF-CO2 sensitivity in these infants may be greater than in adult subjects, 3) 100% O2 reduced CBF significantly, and 4) a decrease in CBF during administration of 100% O2 may be at least partially responsible for the increase in ventilation with hyperoxia.

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