Plastic Collapse Stresses Based on Flaw Combination Rules for Pipes Containing Two Circumferential Similar Flaws

2019 ◽  
Vol 141 (3) ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Yun-Jae Kim ◽  
Valery Lacroix ◽  
Bohumir Strnadel
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Analytical Procedure ◽  
The Other ◽  
Plastic Collapse ◽  
Combination Rules ◽  
Steel Pipes ◽  
Other Hand ◽  
Bending Stresses

When discrete multiple flaws are in the same plane, and they are close to each other, it can be determined whether they are combined or standalone in accordance with combination rules provided by fitness-for-service (FFS) codes. However, specific criteria of the rules are different among these FFS codes. On the other hand, plastic collapse bending stresses for stainless steel pipes with two circumferential similar flaws were obtained by experiments, and the prediction procedure for collapse stresses for pipes with two similar flaws was developed analytically. Using the experimental data and the analytical procedure, plastic collapse stresses for pipes with two similar flaws are compared with the stresses in compliance with the flaw combination criteria. It is shown that the calculated plastic collapse stresses based on the flaw combination criteria are significantly different from the experimental and analytical stresses.

Plastic Collapse Stresses for Pipes With Circumferential Twin Flaws Using Combination Rules

2018 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Yun-Jae Kim ◽  
Valery Lacroix ◽  
Bohumir Strnadel
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Analytical Procedure ◽  
The Other ◽  
Plastic Collapse ◽  
Combination Rules ◽  
Steel Pipes ◽  
Other Hand ◽  
Bending Stresses

When discrete multiple flaws are in the same plane, and they are close to each other, it can be determined whether they are combined or standalone in accordance with combination rules provided by fitness-for-service (FFS) codes, such as ASME, JSME, BS7910, FKM, WES2805, etc. However, specific criteria of the rules are different amongst these FFS codes. On the other hand, plastic collapse bending stresses for stainless steel pipes with circumferential twin flaws were obtained by experiments and the prediction procedure for collapse stresses for pipes with twin flaws were developed analytically. Using the experimental data and the analytical procedure, plastic collapse stresses for pipes with twin flaws are compared with the stresses in compliance with the combination criteria. It is shown that the calculated plastic collapse stresses based on the combination criteria are significantly different from the experimental and analytical stresses.

Allowable Cracks Related to Penetration for Part-Through Cracks in Pipes Subjected to Bending Stresses

2022 ◽  
Author(s):  
Kunio Hasegawa ◽  
Yinsheng Li ◽  
Bohumir Strnadel ◽  
Anees Udyawar
Keyword(s):  
Limit Load ◽  
Service Level ◽  
The Other ◽  
Plastic Collapse ◽  
Local Approach ◽  
Crack Penetration ◽  
Other Hand ◽  
Asme Code ◽  
Bending Stresses

Abstract Fully plastic collapse stresses for circumferentially part-through cracked pipes subjected to bending stresses are estimated by Limit Load Criteria provided by the ASME Code Section XI. Allowable crack depths were determined by using the Limit Load Criteria and that are tabulated in the ASME Code Section XI for different plant service level conditions. On the other hand, crack penetration bending stresses for part-through cracked pipes were estimated by using the Local Approach of Limit Load Criteria. By using these Criteria, the study presented in this paper obtained allowable crack depths at penetration for circumferentially part-through cracked pipes. Comparing the allowable crack depths obtained by both methods for each service level, it is evident that the allowable crack depths at penetration calculated by the Local Approach of Limit Load Criteria are almost always smaller than those at fully plastic collapse stresses calculated by the Limit Load Criteria. It was found that the allowable crack depths provided by the ASME Code Section XI are less conservative for crack penetrations.

About lung surgery

1903 ◽  
Vol 3 (9-10) ◽  
pp. 548-549
Author(s):  
E. Board
Keyword(s):  
Experimental Data ◽  
Lung Tissue ◽  
Lung Surgery ◽  
Operative Intervention ◽  
The Other ◽  
Pulmonary Diseases ◽  
Other Hand

Lung surgery is one of the youngest departments of surgical science. The basis for the development of methods of operative intervention in pulmonary diseases lies in the 1st possibility of preventing the danger of pneumothorax, which (danger) is currently so insignificant that some surgeons consider it even necessary to cause preliminary pneumothorax. On the other hand, the experimental data have shown the possibility of the loss of parts of the lung tissue and the conditions for the healing of its wounds.

scholarly journals Preparation and Thermal and Anti-UV Properties of Chitosan/Mica Copolymer

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Yih-Sheng Huang ◽  
Sheng-Haur Yu ◽  
Yea-Ru Sheu ◽  
Kuo-Shien Huang
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Free Radical ◽  
Physical Properties ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
The Other ◽  
Other Hand

This experiment aims to produce a free radical while annoying the oxidizing-reducing reagent of the ammonium persulfate and the sodium bisulfite under nitrogen, then trigger copolymerization between modified-mica and chitosan to prepare a variety of copolymers. This experiment also aims to study the related properties of these copolymer materials. The experimental data shows that the copolymer has more thermal stability and better absorption of UV than chitosan. But the above physical properties will be less if the mica ratio in copolymer is more than 8%. On the other hand, the SEM photo of the microstructure also shows that the modified mica distributes homogeneously on the surface of the film of the copolymer.

scholarly journals Understanding the Interaction Modes and Reactivity of Trimedoxime toward MmAChE Inhibited by Nerve Agents: Theoretical and Experimental Aspects

2020 ◽  
Vol 21 (18) ◽  
pp. 6510
Author(s):  
Alexandre A. de Castro ◽  
Daniel A. Polisel ◽  
Bruna T. L. Pereira ◽  
Elaine F. F. da Cunha ◽  
Kamil Kuca ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mus Musculus ◽  
Active Site ◽  
Theoretical Calculations ◽  
Nerve Agents ◽  
The Other ◽  
Chemical Weapons ◽  
Reactivation Process ◽  
Other Hand

Organophosphorus (OP) compounds are used as both chemical weapons and pesticides. However, these agents are very dangerous and toxic to humans, animals, and the environment. Thus, investigations with reactivators have been deeply developed in order to design new antidotes with better efficiency, as well as a greater spectrum of action in the acetylcholinesterase (AChE) reactivation process. With that in mind, in this work, we investigated the behavior of trimedoxime toward the Mus musculus acetylcholinesterase (MmAChE) inhibited by a range of nerve agents, such as chemical weapons. From experimental assays, reactivation percentages were obtained for the reactivation of different AChE–OP complexes. On the other hand, theoretical calculations were performed to assess the differences in interaction modes and the reactivity of trimedoxime within the AChE active site. Comparing theoretical and experimental data, it is possible to notice that the oxime, in most cases, showed better reactivation percentages at higher concentrations, with the best result for the reactivation of the AChE–VX adduct. From this work, it was revealed that the mechanistic process contributes most to the oxime efficiency than the interaction in the site. In this way, this study is important to better understand the reactivation process through trimedoxime, contributing to the proposal of novel antidotes.

The Interaction of Carbon Black with Sulfur, MBT and TMTD in Vulcanization

1961 ◽  
Vol 34 (2) ◽  
pp. 588-599 ◽  
Author(s):  
G. A. Blokh ◽  
Ch. L. Melamed
Keyword(s):  
Experimental Data ◽  
Carbon Black ◽  
Chemical Reactions ◽  
The Other ◽  
Considerable Importance ◽  
Physical Aspect ◽  
Active Centers ◽  
Other Hand ◽  
The One

Abstract The experimental data collected on the interaction of active centers of carbon black with the rubber on the one hand and of the active centers of carbon black with the sulfur and accelerators, and also with the antioxidants, on the other hand, provide a sound basis for belief that the problem of reinforcement of rubber by active fillers in the process of vulcanization cannot be explained from the physical aspect alone. The facts indicate the considerable importance of the chemical reactions between the active groups of carbon black and the compounding ingredients in the course of vulcanization.

A Hybrid Semi-empirical Model for Lean Blow-Out Limit Predictions of Aero-engine Combustors

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Bin Hu ◽  
Yong Huang ◽  
Jianzhong Xu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Empirical Model ◽  
The Other ◽  
Model Parameters ◽  
Model Parameter ◽  
Other Hand ◽  
Aero Engine ◽  
Semi Empirical

According to the Lefebvre's model and flame volume (FV) concept, an FV model about lean blow-out (LBO) was proposed by authors in early study. On the other hand, due to the model parameter (FV) contained in FV model is obtained based on the experimental data, FV model could only be used in LBO analysis instead of prediction. In view of this, a hybrid FV model is proposed that combines the FV model with numerical simulation in the present study. The model parameters contained in the FV model are all estimated from the simulated nonreacting flows. Comparing with the experimental data for 11 combustors, the maximum and average uncertainties of hybrid FV model are ±16% and ±10%.

Evaluation of Alignment Rules Using Stainless Steel Pipes With Non-Aligned Flaws

2009 ◽  
Author(s):  
Kunio Hasegawa ◽  
Katsumasa Miyazaki ◽  
Koichi Saito ◽  
Bostjan Bezensek
Keyword(s):  
Stainless Steel ◽  
Limit Load ◽  
Plastic Collapse ◽  
Paper Briefly ◽  
Limit Loads ◽  
Bending Tests ◽  
Steel Pipes ◽  
Four Point Bending ◽  
Close Proximity ◽  
As Stress

Multiple flaws such as stress corrosion cracks are frequently detected in the same welded lines in pipes. If multiple discrete flaws are in close proximity to one another, alignment rules are used to determine whether the flaws should be treated as non-aligned or as coplanar. Alignment rules are provided in fitness-for-service codes, such as ASME, JSME, API 579, BS 7910, etc. However, the criteria of the alignment rules are different among these codes. This paper briefly introduces these flaw alignment rules, and four-point bending tests performed on stainless steel pipes with two non-aligned flaws. The experimental plastic collapse stresses are determined from the collapse loads and compared with collapse stresses calculated from the limit load criteria. The limit loads are obtained for single non-aligned or aligned coplanar flaws in accordance with the alignment rules. On this basis, the conservatism of the alignment rules in the above codes is assessed.

scholarly journals A note on dynamical compensation and its relation to parameter identifiability

2017 ◽  
Author(s):  
Omer Karin ◽  
Uri Alon ◽  
Eduardo Sontag
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
The Other ◽  
Apparent Discrepancy ◽  
Parameter Identifiability ◽  
Other Hand ◽  
The Face ◽  
System Variables

AbstractWe recently identified a motif for dynamical compensation (DC) – a property where a system maintains the dynamics and steady-state of a regulated variable robust in the face of fluctuations in key parameters. Such parameters are therefore unidentifiable from measurements of the regulated variable at steady-state. On the other hand, since the models showing dynamical compensation are typically non-redundant, their parameters are identifiable from experimental data. We clarify this apparent discrepancy by requiring that the parameters of DC circuits be identifiable both away from steady-state and when measuring other system variables. We use this observation to provide a definition for DC in terms of parameter identifiability and discuss its relevance for the examples provided in Karin et al.

Skin Friction

1911 ◽  
Vol 15 (59) ◽  
pp. 115-118
Author(s):  
W. Ellis Williams
Keyword(s):  
Experimental Data ◽  
Skin Friction ◽  
Laboratory Experiments ◽  
Surface Friction ◽  
Normal Pressure ◽  
The Other ◽  
Other Hand

Among the various experimental data which are required in the discussion of the theory and design of the aeroplane, there are none of greater importance than those relating to surface friction, while at the same time there are none about which greater uncertainty prevails.Owing to the difficulty of separating skin friction from head resistance, very little can be learnt from observations on actual machines in flight, while on the other hand, if we turn to laboratory experiments on the resistance of planes, we are met with the most bewildering variations in the values obtained for it. Many of the most careful experimenters make out that it is quite inappreciable while others maintain that it is from 1—4 per cent. of the normal pressure, and therefore forms an important part of the drift at small angles of attack.

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