bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impact of Thermal Ageing Embrittlement on Westinghouse and Combustion Engineering-Designed Pressurized Water Reactor Pressurizers Based on Pressure-Temperature Limit Comparison
Authors: Scott Alexandria M. , Turicik Louis W. , Hall J. Brian , Udyawar Anees , Freed Amy E. , Long Elliot J. 
Published: November 2022

Abstract
The low alloy steel pressurizer (PZR) vessels in pressurized water reactor (PWR) nuclear power plants are potentially susceptible to embrittlement due to thermal ageing over the life of the plant (40–80 years). This paper determines the amount of PZR thermal ageing embrittlement, which can be accommodated based on a comparison of PZR and the U.S. NRC approved reactor pressure vessel (RPV) 10 CFR 50, Appendix G Pressure-Temperature (P-T) limit curves for the current operating U.S. PWR fleet. The maximum amount of postulated thermal ageing embrittlement, in terms of a shift in nil-ductility reference temperature (ΔRTNDT), which is permissible before the generic PZR P-T limit curves exceed the NRC-approved RPV P-T limit curves is provided in this paper. The generic P-T limit curves are determined for current operating U.S. PWR representative Westinghouse and Combustion Engineering (CE) PZR designs for various levels of postulated thermal ageing embrittlement. The locations for consideration within the PZR are the cylindrical shell to bottom head girth weld (includes consideration of the adjacent shell longitudinal seam weld), lower head region in the vicinity of the heater sleeve penetrations, and the surge nozzle corner region. The methodology to calculate the PZR P-T limit curves is per 10 CFR 50, Appendix G and the 2017 Edition of ASME Section XI, Appendix G. The PZR thermal ageing ΔRTNDT values determined in this paper could be compared to estimated or empirical values of thermal ageing embrittlement to determine if or when PZR embrittlement may impact a plant’s 10 CFR 50, Appendix G heatup and cooldown P T limit curves, and any primary loop pressure boundary design fracture mechanics evaluations.
Diagnosis, Modelling and Assessment of Transient Pressure Events Based on Observed In-Field Evidence
Authors: Prewitt T. J. , Bednorz Michael 
Published: November 2022

Abstract
Intermittent pipe movement due to transient pressure events including vapor column collapse or water hammer events can impart large strains into the pipe, cause damage to the support structure, damage coatings, and cause damage or failure of the pipe. This paper will present a method that has been used with success for determining the pipe stresses and strains and possible cause associated with a transient pressure event based on coating damage evidence gathered from in-field assessments. After constructing a hydraulic model of the piping system, various transient events were modelled to obtain resulting pressure over the transient event’s period at key points along the piping system, such as valves and elbows. A second, more refined finite element model was created to incorporate the pressure values to determine the resulting displacements and stresses to relate to the in-field measurements of the region in question. By comparing the displacements in the model to the field evidence, the models were calibrated, and evaluation of the likely cause of coating damage found in the field was able to be performed. Moreover, the stresses in the pipe during the event are able to be assessed which allows for damage assessments to be conducted and allows for corrective actions to take place. Transient events assessed ranged from valve openings and closures, pump start up, and vapor column collapse.
Modeling Electric-Potential for a Crack Subjected to Corrosion Under Static and Cyclic Loading
Authors: Prakash Raghu V. , Anish C. , Sampath Dhinakaran 
Published: November 2022

Abstract
High strength steels are increasingly being used in applications such as ship hulls and oil and gas pipelines which are subjected to corrosive environment. These steel grades exhibit more than an order of magnitude higher crack growth rates in corrosive environments compared with the crack growth rates in air. A mathematical model is developed based on the slip dissolution mechanism to evaluate the chemistry and potential distributions in the occluded crack. The species distribution due to diffusion and ion migration is evaluated by considering the effect of ferrous hydroxide formation on the transport properties in the electrolyte. It is also found that the potential and pH drop in the crack is affected by the crack tip stress and strain fields. The dissolution of iron at the crack tip is enhanced by the pH drop. Both steady state and transient numerical studies are carried out to determine the evolving crack geometry. Thus, by considering reactions inside the crack, a better representation of the species and potential distributions can be obtained.
Fracture Toughness Behavior of Welded Service Aged Carbon Steels in Mildly Sour Waters
Authors: Rollins Brandon C. , Penso Jorge 
Published: November 2022

Abstract
Cracking of steels in refinery H2S service occurs in two regimes: 1) low pH and 2) high pH. Cracking in the low pH regime (pH &lt; 6 or 7) is associated with ingress of hydrogen from metal dissolution with H2S poisoning the hydrogen recombination reaction. In the high pH regime (pH &gt; 7), cracking requires the presence of species other than just H2S. While this has been a subject of interest since the failure of an amine absorber tower in 1984, limited laboratory testing has been conducted in either regime. The majority of test data that does exist was from studies conducted in more aggressive environments, such as NACE A or NACE B solutions. Additionally, most of the work was conducted on more modern steels rather than service aged of vintage steel. The lack of available data inhibits the ability to perform fitness for service (FFS) assessments without using overly conservative approaches.
A recent test program was undertaken to evaluate the fracture toughness properties of the weld heat-affected zone (HAZ) of an ex-service steel in mildly acidic sour water environments more typical of the downstream refining industry. The results of the test program, including the test environment and approach are discussed. In addition to the test program, the current state of understanding sour water cracking is reviewed relative to both the low pH and high pH regimes. The gaps in the current knowledge are discussed.
The Standardization Work Status and Development Trend of High Pressure Hydrogen Storage Technology
Authors: Jia Xiaoliang , Chen Zhiwei , Li Xiang , Bo Ke , Ji Fang 
Published: November 2022

Abstract
Hydrogen energy is a kind of efficient, clean and pollution-free green energy, so it is considered as an important part of future energy structure. With more and more attention paid to hydrogen energy in the world, many countries have started the strategic layout, development and utilization of hydrogen energy. Standards provide a crucial technical support for guiding technological advance, industrial transformation and the direction of progress. China and other countries in the world have begun to formulate hydrogen energy standards. High pressure hydrogen storage is one of the most important parts in hydrogen energy industry. The maturity of high pressure hydrogen storage technology directly determines whether the strategic goal of hydrogen energy can be realized. Hence, a brief comparative study has been made between China national standards and International organization for standardization standards based on the following five aspects: technical code for hydrogen fueling station construction, hydrogen systems, metallic material compatibility in hydrogen atmosphere, construction of hydrogen storage vessels, inspection of in-service pressure equipment used in hydrogen fueling station. In order to promote the high-quality development of hydrogen energy industry and achieve the goal of “carbon neutrality” and “peak emissions” in China, it is necessary to strengthen standardization in the test methods for evaluating material compatibility in hydrogen atmosphere and method for hydrogen storage vessels construction used in hydrogen fueling station.
Data-Driven Stress Intensity Factor Solutions for Axial Outside Surface Cracks in Thick-Wall Cylinders
Authors: Zhu Xian-Kui , Zhu Jesse B. , Duncan Andrew J. 
Published: November 2022

Abstract
Crack assessment relies on the linear elastic or elastic-plastic fracture mechanics that requires calculation of stress intensity factor, K, in the fitness for service codes, such as API 579 and ASME BPVC Section XI. For a surface crack in a cylinder, the K calculation becomes calculating the influence coefficients G0 and G1 of K in those codes. API 579 provided accurate tabular data of G0 and G1 for selected cylinder sizes (t/Ri), crack aspect ratios (a/c), crack depths (a/t), and crack tip locations. Recently, the curve-fit solutions of G0 and G1 were obtained for surface cracks at the deepest and surface points. For an arbitrary cylinder size, however, three-parameter interpolations are still needed to estimate the G0 and G1.
To avoid performing the complex interpolation, this paper adopts the state-of-the-art machine learning technology to develop data-driven K solutions based on the tabular data of G0 and G1 given in API 579 for axial outside semi-elliptical surface cracks in thick-wall cylinders at the deepest and surface points. The machine learning method utilizes an artificial neural network (ANN), activation function, and optimal learning algorithm to learn and to determine G0 and G1 as a function of the cylinder size (t/Ri), aspect ratio (a/c), and crack depth (a/t) for axial outside surface cracks at the deepest and surface points. The proposed data-driven solutions of G0 and G1 are validated by available curve-fit solutions for the axial outside surface cracks.
State of the Art in CUF-Based Fatigue Assessment & Related Issues From Regulatory and Code Perspectives for Long-Term Operation
Authors: Garud Yogendra 
Published: November 2022

Abstract
Metal fatigue is likely to continue as an important issue to be managed for the anticipated or extended long-term operation of many engineering systems, both at the design stage and during service. Most parts are designed to start with an un-cracked condition and with the goal of their non-failure during operation. As such, the Code procedures and regulations have been developed to address the possibility of (not) developing a crack of engineering significance during the service. This possibility has been addressed on the basis of ensuring adequacy of fatigue performance for a specified period of operation, and the primary tool used for its assessment utilizes the cumulative usage factor (CUF) parameter. Several design factors/assumptions including the use of stress versus load-cycles (S–N) materials tests data and potential environmental effects in service govern the estimation and application of this CUF parameter.
Over the past few decades, many changes or adjustments have influenced the overall CUF-based assessment with some differences also between various international standards and procedures. For the long-term operation (LTO) the regulatory approach has resulted in the time-limited aging analysis (TLAA) or revalidation for fatigue. This paper provides a state-of-the-art overview of these developments, internationally, both in the Code/design rules/norms and the regulatory approaches. Also included is a brief discussion on various technical proposals in active development which are likely to influence the CUF-based assessment and/or to address conservatism in the existing rules and regulations. Brief comments are noted on the characteristically deterministic manner of these approaches and their addressing of the uncertainty in inputs via conservative factors, vis-à-vis a probabilistic approach.
Effect of Pitch Ratio and Flat Bar Support Conditions on FEI Threshold for Low MDP Parallel Triangular Array – Single-Phase Water-Flow
Authors: Elhelaly Amro , Hassan Marwan , Weaver David , Moussa Soha Eid 
Published: November 2022

Abstract
An intensive research program has been initiated to provide a better understanding of the fundamental aspects of FEI in tube bundles. This paper reports the findings of an experimental investigation utilizing a newly commissioned experimental rig. Initially, a series of water-flow experiments were conducted in a fully flexible, low mass damping parameter, parallel triangular tube array (with a cluster of 9 brass rods). To investigate the effect of pitch ratio on the onset of FEI, four different pitch-to-diameter ratios of 1.27, 1.37, 1.48, and 1.62 were utilized and presented in this study. Moreover, to illustrate the dynamic effect of flat bar support conditions on the stability threshold of FEI, a series of experiments were conducted in each pitch ratio with varied tube/support clearances.
A full description of the flow loop, including the utilized instrumentation, and troubleshooting challenges encountered in commissioning the test rig is discussed. Moreover, the obtained results of the single-phase flow experiments are presented. The current results show good agreement with the available data from previous investigations, which established the confidence level needed to start two-phase experiments.
Resetting of zircon inclusions in garnet: Implications for elastic thermobarometry
Authors: Campomenosi Nicola , Angel Ross J. , Alvaro Matteo , Mihailova Boriana 
Published: November 2022

Abstract
Elastic thermobarometry of host-inclusion systems for back-calculating pressure (P) and temperature (T) conditions of inclusion entrapment relies on the assumption that the hostinclusion rheology is purely elastic. In this study, we have explored both the elastic and non-elastic behavior of zircon-in-garnet (ZiG) systems by in situ Raman spectroscopy at high T and ambient P. We show that upon heating, plastic relaxation takes place immediately after the zircon inclusions experience tensile stress conditions with respect to a free crystal at the same T. On subsequent cooling, the inclusions develop a new stress state, and thus the inclusion pressures have been reset from those corresponding to their original entrapment. Resetting of inclusion pressures therefore strongly depends on the exhumation P-T path. This explains why elastic thermobarometry using ZiG systems is reliable when applied to low-P high-T rocks where the cooling path after inclusion entrapment passes quickly into the compression domain of the inclusion. On the other hand, high-P rocks exhumed along quasi-isothermal paths take zircon inclusions into the tensile domain where they are reset until significant cooling commences at low P. ZiG systems in ultrahigh-P rocks therefore commonly indicate pressures on clockwise exhumation paths instead of the conditions of original entrapment.
Postoperative analgesic effects of the quadratus lumborum block III and
transversalis fascia plane block in paediatric patients with developmental
dysplasia of the hip undergoing open reduction surgeries: a double-blinded
randomised controlled trial
Authors: Huang Congcong , Zhang Xiaoguang , Dong Chaoxuan , Lian Chunwei , Li Jun , Yu Lingzhi 
Published: November 2022

Objective
To evaluate the analgesic effectiveness of two novel regional nerve
blocks in paediatric patients with developmental dysplasia of the hip
(DDH) after open reduction surgeries.

Design
Prospective, double-blinded, randomised controlled trial.

Setting
2 tertiary teaching hospitals in China between August 2017 and July
2018.

Participants
110 paediatric patients aged 2–10 years with DDH undergoing open
reduction surgeries were recruited, 95 were randomised and 90 were
included in the final analysis.

Interventions
Random assignment to quadratus lumborum block III (QLB III) group,
transversalis fascia plane block (TFPB) group and the control (no region
nerve block) group.

Primary and secondary outcome measures
The primary outcome was the Face, Legs, Activity, Cry and
Consolability (FLACC) Scale Scores. Secondary outcomes included
perioperative opioid consumption, the time until first press of
nurse-controlled analgesia/patient-controlled analgesia (NCA/PCA) pump
and the total counts number of pressing, length of postanaesthesia care
unit (PACU) stay, length of hospital stay, parental satisfaction with
pain management and adverse events.

Results
Mean FLACC Scores were significantly lower in QLB III group and TFPB
group while in the PACU and for 48 hours postoperatively, compared with
control group (p<0.0001, p<0.0001, respectively). No differences
were found for FLACC Scores between QLB III group and TFPB group,
neither at rest (p=0.0402) nor while posture changing (p=0.0306). TFPB
prolonged the first-time request for NCA/PCA analgesia, and decreased
the total number of pressing counts, compared with QLB III (22.5 (16.2
to 28.7) vs 11.7 (6.6 to 16.8), p<0.0001; 2.4 (1.3 to 3.6) vs 3.8
(2.8 to 4.8), p=0.0111, respectively). No patient experienced any
adverse events.

Conclusions
We suggested that both ultrasound-guided QLB III and TFPB should be
considered as an option for perioperative analgesia in children with DDH
undergoing open reduction surgeries. TFPB was superior to the QLB III
because it prolonged the first-time request for NCA/PCA analgesia and
decreased the total counts number of pressing.

Trial registration number
NCT03189966/2017.
Parenting, child development and primary care—‘Crescer em Grande!’
intervention (CeG!) based on the Touchpoints approach: a cluster-randomised
controlled trial protocol
Authors: Fareleira Filipa , Xavier Maria Raul , Velte Julia , Teixeira Andreia , Martins Carlos 
Published: November 2022

Introduction
Despite support for parenting being already recognised as a
priority, there remains a paucity of evidence on how to facilitate its
adoption in regular visits of maternal and child health primary care
(PC). We describe the protocol for a study to assess the effect of an
innovative universal Touchpoints-based intervention—‘Crescer em Grande!’
(CeG!) - when supporting the process of transition to parenthood and
early infancy, at multiple PC units.

Methods and analysis
A cluster-randomised trial will be conducted in 12 PC units
(clusters) from the Lisbon metropolitan area, Portugal. Participants
will be a minimum of three family physicians and one nurse/unit, as well
as 216 expecting parents and future babies until 18 months who are using
the PC services. Sites will be randomised to either the CeG! or usual
care. The CeG! will consist of: (1) the integration of the Touchpoints
approach in PC maternal and well-child visits, with the support of 28
leaflets for parents to file in a folder; plus (2) training for PC
providers on how to perform the CeG! into existing practice. Parents
will be required to fill in questionnaires at point throughout their
child’s 18-month, mostly online. The primary outcome will be the
self-perception of parental competence (Parenting Sense of Competence
Scale). Other outcomes include: family functioning, couple dynamics,
mental health, well-being/quality of life, psychological experience of
pregnancy, attachment, child development. Acceptability, satisfaction
and feasibility of CeG! will also be obtained from providers’ and
parents’ perspectives. Costs associated with delivering the CeG! will be
calculated. Study analyses will be under the principle of
intention-to-treat.

Ethics and dissemination
Approval was obtained from the Ethics Committee of the Regional
Health Administration. The results will be shared with participants and
disseminated via peer-reviewed published papers, presentations at
scientific and professional conferences.

Trial registration number
NCT90692907
Pregnancy-related interventions in mothers at risk for gestational
diabetes in Asian India and low and middle-income countries (PRIMORDIAL
study): protocol for a randomised controlled trial
Authors: Vasan Senthil K , Jobe Modou , Mathews Jiji , Cole Fatoumata , Rathore Swathi , Jarjou Ousman , Thompson Dylan , Jarde Alexander , Bittaye Mustapha , Ulijaszek Stanley , Fall Caroline , Osmond Clive , Prentice Andrew , Karpe Fredrik 
Published: November 2022

Introduction
Lifestyle modification is the mainstay of gestational diabetes
mellitus (GDM) prevention. However, clinical trials evaluating the
safety and efficacy of diet or physical activity (PA) in low-income and
middle-income settings such as Africa and India are lacking. This trial
aims to evaluate the efficacy of yoghurt consumption and increased PA
(daily walking) in reducing GDM incidence in high-risk pregnant
women.

Methods and analysis
The study is a 2×2 factorial, open-labelled, multicentre randomised
controlled trial to be conducted in Vellore, South India and The Gambia,
West Africa. ‘High-risk’ pregnant women (n=1856) aged ≥18 years and ≤16
weeks of gestational age, with at least one risk factor for developing
GDM, will be randomised to either (1) yoghurt (2) PA (3) yoghurt +PA or
(4) standard antenatal care. Participants will be followed until 32
weeks of gestation with total active intervention lasting for a minimum
of 16 weeks. The primary endpoint is GDM incidence at 26–28 weeks
diagnosed using International Association of the Diabetes and Pregnancy
Study Groups criteria or elevated fasting glucose (≥5.1 mmol/L) at 32
weeks. Secondary endpoints include absolute values of fasting plasma
glucose concentration at 32 weeks gestation, maternal blood pressure,
gestational weight gain, intrapartum and neonatal outcomes. Analysis
will be both by intention to treat and per-protocol. Continuous outcome
measurements will be analysed using multiple linear regression and
binary variables by logistic regression.

Ethics and dissemination
The study is approved by Oxford Tropical Research Ethics Committee
(44–18), ethics committees of the Christian Medical College, Vellore
(IRB 11367) and MRCG Scientific Coordinating Committee (SCC 1645) and
The Gambia Government/MRCG joint ethics committee (L2020.E15). Findings
of the study will be published in peer-reviewed scientific journals and
presented in conferences.

Trial registration number
NCT18467720.