bluuebunny/crossref_metadata_2025 huggingface dataset:
The social function of intellectual property and government intervention in mitigating the pandemic: A perspective from Indonesia
Authors: Mayana Ranti F. , Santika Tisni
Published: November 2022

Indonesia declared Corona Virus Disease 2019 (COVID‐19) a Public Health Emergency based on Presidential Decree No. 11 of 2020 considering the extensive victims and extraordinary impacts. This study analyzes how Indonesia addresses the social function of intellectual property and government intervention in mitigating the pandemic. This study shows that outside the patent waiver provisions, implementation is the key. Indonesian Government has set a strategic framework in accordance with the guidelines of the WHO by simultaneously takes two strategies of vaccine provision and procurement: First, purchasing vaccines from abroad and/or collaborating with national and/or international institutions, Second, the development of ‘Vaksin Merah Putih’ (Red and White Vaccine) independently in the country through a triple helgix synergy involving the government institutions/ministries, universities, and industries. The provision of COVID‐19 Vaccines in Indonesia is free as a form of responsibility and presence of the state. Government is also continuously expanding its public communication network to eliminate vaccine hesitancy. Lastly, Indonesia has adopted the TRIPs Waiver provisions through the Indonesian Patent Law, Government Regulation Number 77 of 2020 concerning Procedures for Patent Implementation by the Government, Regulation of the Minister of Law and Human Rights No. 14 of 2021 concerning Amendments to the Regulation of the Minister of Law and Human Rights No. 30 of 2019 concerning Procedures for Granting a Compulsory Patent License. These regulations will later become the basis for the government, whether it will eventually implement a patent license through a compulsory license system or a government use the patent system not only for the COVID‐19 vaccine but also other essential medicines in mitigating the pandemic.
Symptomatology and Neuropathology of patients presenting with focal cortical signs
Authors: Ishihara Kenji , Fukui Toshiya , Kawamura Mitsuru , Shiota Jun‐ichi , Nakano Imaharu
Published: November 2022

Here, we describe two patients who presented with focal cortical signs and underwent neuropathological examination. Case 1 was a 73‐year‐old woman with progressive speech disorder and abnormal behavior. She showed agraphia of the frontal lobe type, featured by the omission of kana letters when writing, other than pyramidal tract signs, pseudobulbar palsy, and frontal lobe dementia. Neuropathological examination, including TAR DNA‐binding protein 43 (TDP‐43) immunohistochemistry, revealed bilateral frontal and anterior temporal lobe lesions accentuated in the precentral gyrus and posterior part of the middle frontal gyrus. Both upper and lower motor neurons showed pathological changes compatible with amyotrophic lateral sclerosis. Case 2 was a 62‐year‐old man with progressive speech disorder and hand clumsiness. He had a motor speech disorder, compatible with apraxia of speech, and limb apraxia of the limb‐kinetic and ideomotor type. Neuropathological examination revealed degeneration in the left frontal lobe, including the precentral gyrus, anterior temporal, and parietal lobe cortices. Moreover, numerous argyrophilic neuronal intracytoplasmic inclusions (Pick body) and ballooned neurons were observed in these lesions and the limbic system. The pathological diagnosis was Pick disease involving the peri‐Rolandic area and parietal lobe. In these two cases, the distribution of neuropathological changes in the cerebral cortices correlated with the clinical symptoms observed.
Allogeneic Tendon Transplantation for the Treatment of Pathological Patellar Ligament Defect in Children: Technical Note and 4‐Year Follow‐Up
Authors: Zhou Min , Long Yi , Yu Menglei , Guo Jiang , Tang Yiyong , Li Fangqi , Li Qingyue , Zhang Yuanhao , Zheng Zhenze , Hou Jingyi , Yang Rui
Published: November 2022

Objective

The absence of patellar ligament will bring about a severe negative impact on daily life. Many reconstruction techniques have been described in adults. However, there is a lack of technical introduction regarding the reconstruction of the patellar ligament in children. The purpose of this study was to report a surgical technique for reconstructing the patellar ligament in children.

Method

A retrospective analysis of the clinical data on a patellar ligament (tendon sheath fibroma) patient with allogeneic tendon reconstruction. An 8‐year‐old child with postoperative recurrence of left patellar ligament tumor was enrolled in our study. Anterior tibialis tendon allograft was used to reconstruct the patellar ligament after complete resection of the patellar ligament for the tumor. The tunnels were constructed on the deep surface of the tibial tubercle and the root of the quadriceps tendon (to decrease the harmful impact on patella development), respectively. The allogeneic tendon was passed through the tunnels above in the shape of “8,” and the two ends of the tendon were attached to the bleeding bone bed at the inferior edge of the patella with suture anchors to achieve better bone‐tendon healing. During the follow‐up, the knee's range of motion and imaging manifestations were recorded.

Result

Postoperative pathology suggests chondromesenchymal hamartoma, a rare benign soft tissue tumor different from the previous operation (tendon sheath fibroma). During the 4‐year follow‐up, the patient's active range of motion of the knee achieved 0° to 120°; and the patient could walk normally without any external help. Physical examinations (the apprehension sign and J sign) showed no ligamentous instability or patellar ligament tenderness. Imaging analysis showed that the ratio length of the patellar ligament to the patella was almost normal. The integrity, continuity, and shape of the allogeneic ligament showed excellent results in MRI. Combined with clinical and imaging findings, allogeneic tendon patellar ligament reconstruction was deemed successful.

Conclusion

Allogeneic ligament reconstruction technique can provide a treatment option by reconstructing the extensor mechanism, minimizing the impact on patellar development, and augmenting biological healing for children with the absence of the patellar ligament.
Weak crassulacean acid metabolism and other xerophytic adaptive traits in the genus Beaucarnea Lem. (Asparagaceae)
Authors: Reyes‐García Casandra , Orellana Roger , Dzib Ek Susana , Peniche Aké Stephany , Tamayo‐Chim Manuela , Echevarría‐Machado Ileana , Carrillo Lilia , Espadas‐Manrique Celene
Published: November 2022

The genus Beaucarnea (Asparagaceae) has economic value as an ornamental plant but also has ecological importance. Nonetheless, habitat, physiological traits and growth parameters of this genus remain largely unknown. We characterized the environmental ranges of Beaucarnea inermis, B. gracilis and B. pliabilis; and screened for the presence of physiological adaptations to drought (biomass allocation, presence of crassulacean acid metabolism [CAM] and its effect on plant water use). We performed experiments in 3‐ and 5‐year‐old nursery‐grown plants of the three species, measured dry mass accumulation in leaves/stems/roots and screened for CAM using gas exchange, titratable acidity and δ13C. We performed a second experiment on the water and light use responses of B. pliabilis under drought treatment. We found that B. gracilis was limited to xerophytic scrubs (precipitation >400 mm yr−1), while B. pliabilis and B. inermis (precipitation >500 and 700 mm year−1, respectively) inhabited dry forests. Beaucarnea gracilis had the lowest dry mass and allocation to leaves, while B. inermis showed the opposite pattern. Only B. pliabilis exhibited small but significant acid fluctuations, characterized as weak CAM, along with high proline content. Acid concentration contributed in 2.7% of the daily carbon during the wet season but represented most of the carbon in the dry season, under closed stomata and had an important contribution to osmolality. Thus, CAM is described for the first time in the genus Beaucarnea, but was only present in one of three species, warranting exploration of this metabolism in the remaining species of this genus.
Efficacy of strip seeding to restore grassland plant communities
Authors: Shaw Julea A. , Roche Leslie M. , Gornish Elise S. , Rayburn Andrew P. , Zamora Aubrianne J. , Laca Emilio
Published: November 2022

Strip seeding is a novel restoration practice of strategically planting in strips, resulting in alternating seeded and unseeded areas to target efforts and reduce costs while achieving ecological outcomes similar to conventional methods of seeding entire sites. However, there has been limited work testing the efficacy of this method, including how strip width and percent seeded area affect restoration outcomes. We evaluated four native grass strip seed treatments (33%, 50% narrow, 50% wide, and 66% of area seeded), an unseeded control, and a conventional 100% seeded control to investigate: (1) how plant communities in seeded and unseeded strips change over time; (2) how initial strip width affect native species biomass, invasive species biomass, and plant species diversity; and (3) cost‐effectiveness of strip seeding in terms of management costs and benefits accrued. Four years post‐seeding, seeded and unseeded strips exhibited unique plant communities; seeded strips were characterized by native perennial grasses while unseeded strips had a higher abundance of annual forbs (majority non‐native) and non‐native annual grasses. Plant communities were similar within strips across strip seeding treatments. Invasion resistance and productivity scaled with percent area initially seeded, but by year four all strip seed treatments (33–66%) provided similar benefits to conventional seeding (100%). Overall, this suggests strip seeding is a promising, cost‐effective method to restore targeted species and maintain native grassland communities. Further research is needed on long‐term effects, ecological and economic barriers and opportunities, and provisioning of a broad suite of ecosystem services across different environmental contexts and management practices.
Linear Regression and Its Inference on Noisy Network-Linked Data
Authors: Le Can M. , Li Tianxi
Published: November 2022

Linear regression on network-linked observations has been an essential tool in modelling the relationship between response and covariates with additional network structures. Previous methods either lack inference tools or rely on restrictive assumptions on social effects and usually assume that networks are observed without errors. This paper proposes a regression model with non-parametric network effects. The model does not assume that the relational data or network structure is exactly observed and can be provably robust to network perturbations. Asymptotic inference framework is established under a general requirement of the network observational errors, and the robustness of this method is studied in the specific setting when the errors come from random network models. We discover a phase-transition phenomenon of the inference validity concerning the network density when no prior knowledge of the network model is available while also showing a significant improvement achieved by knowing the network model. Simulation studies are conducted to verify these theoretical results and demonstrate the advantage of the proposed method over existing work in terms of accuracy and computational efficiency under different data-generating models. The method is then applied to middle school students' network data to study the effectiveness of educational workshops in reducing school conflicts.
ZAP:Z-Value Adaptive Procedures for False Discovery Rate Control with Side Information
Authors: Leung Dennis , Sun Wenguang
Published: November 2022

Adaptive multiple testing with covariates is an important research direction that has gained major attention in recent years. It has been widely recognised that leveraging side information provided by auxiliary covariates can improve the power of false discovery rate (FDR) procedures. Currently, most such procedures are devised with p-values as their main statistics. However, for two-sided hypotheses, the usual data processing step that transforms the primary statistics, known as p-values, into p-values not only leads to a loss of information carried by the main statistics, but can also undermine the ability of the covariates to assist with the FDR inference. We develop a p-value based covariate-adaptive (ZAP) methodology that operates on the intact structural information encoded jointly by the p-values and covariates. It seeks to emulate the oracle p-value procedure via a working model, and its rejection regions significantly depart from those of the p-value adaptive testing approaches. The key strength of ZAP is that the FDR control is guaranteed with minimal assumptions, even when the working model is misspecified. We demonstrate the state-of-the-art performance of ZAP using both simulated and real data, which shows that the efficiency gain can be substantial in comparison with p-value-based methods. Our methodology is implemented in the R package zap.
Cultural competencies in Polish and Lithuanian nurses: A cross‐sectional comparative study
Authors: Ślusarska Barbara , Marcinowicz Ludmiła , Blaževičienė Aurelija
Published: November 2022

Background

Cultural competencies are known as a multidimensionalconstruct; however, they usually refer to an individual’s sensitivity orcultural attitudes, cultural awareness, knowledge, and skills.

Aim

The aim of the study was to compare the cultural competences of nurses in Poland and Lithuania based on an adaptation of the Nurse Cultural Competence Scale (NCCS).

Design

The design was a comparative cross‐sectional study.

Methods

A total of 383 Polish nurses and 184 Lithuanian nurses took part in the study. The questionnaires of the NCCS—Polish version (NCCS‐v.PL) and the NCCS—Lithuanian version (NCCS‐v.L) were used after linguistic adaptation and an evaluation of psychometric properties.

Results

As a result of the comparative analysis, a higher general level of cultural competences (based on the NCCS) was found in the Lithuanian group M‐148.09 (SD = 22.85). The results show statistically significant differences among the respondents in the subscale of Nurse Cultural Competence Scale‐Cultural Knowledge (NCCS‐CK; p ˂ 0.001); higher competences of the nurses were found in the Group LT (M = 31.05; SD = 6.75) than in the Group PL (M = 28.82; SD = 7.82). In the group of Polish nurses (Group PL), the intensity of cultural competences was found to increase along with age (NCCS‐v.P r = 0.157, p < 0.05); this, however, was not observed in the Group LT (NCCS‐v.LT, p > 0.05).

Conclusions

Both the nurses in Poland and in Lithuania are characterised by an average level of cultural competences. Diversity in the level of cultural competences was found in both groups depending on age, education and work experience.
“I wanna look like the person in that picture”: Linking selfies on social media to cosmetic surgery consideration based on the tripartite influence model
Authors: Wang Yuhui , Qiao Xiuqing , Yang Jing , Geng Jingyu , Fu Lin
Published: November 2022

Based on the tripartite influence model, the present study linked investment in others' selfies on social media to facial dissatisfaction and cosmetic surgery consideration. We also tested the mediating role of appearance comparisons and general attractiveness internalization in these relationships. Additionally, potential gender differences in the proposed model were examined. A sample of 884 Chinese adolescents (mean age = 16.80 ± 0.92, ranging from 14 to 19 years old) completed self‐reported measures of investment in others' selfies, appearance comparisons, general attractiveness internalization, facial dissatisfaction, and cosmetic surgery consideration. Results showed that investment in others' selfies was positively associated with facial dissatisfaction and cosmetic surgery consideration. Path analysis further revealed that investment in others' selfies was associated with appearance comparisons and general attractiveness internalization, which in turn were associated with facial dissatisfaction, and then facial dissatisfaction was related to cosmetic surgery consideration. Additionally, there were indirect associations between investment in others' selfies and cosmetic surgery consideration via general attractiveness internalization and facial dissatisfaction respectively, but not via appearance comparisons. No gender difference was found in the proposed model. Findings of the present study provide preliminary support for the tripartite influence model in the context of investment in others' selfies on social media and cosmetic surgery consideration and enrich the literature on body image and cosmetic surgery in the Chinese context.
Hacking Hekla: Exploring the dynamics of digital innovation in rural areas
Authors: Falter Magdalena , Jóhannesson Gunnar Thór , Ren Carina
Published: November 2022

This article explores innovation initiatives in rural communities in Iceland conveyed through the implementation and perceived outcomes of the hackathon Hacking Hekla. Digitalisation is often proposed as a new, all‐purpose tool for regional development that responds to rural challenges innovatively. However, the digital role is often less clear when examining finer development practices. Hackathons are frequently applied to achieve instant economic and societal change. Through the example of Hacking Hekla, we research the challenges and outcomes of creative interventions and critically explore the value of innovation and digitalisation in the context of rural development in Iceland. Based on action research, we use the hackathon as a tool for knowledge generation and intervention in regional policy discourse with the intention to foster applied digital innovation. Data were collected using qualitative semi‐structured interviews. The study demonstrates a gap between regional policies emphasising digital innovation and innovation practices on the ground and argues that fostering digital innovation in rural communities is a complex process that could demonstrate effects only in the long term.
An objective comparison of two pulse oximetry sensors with different adhesive systems on healthy human volunteers based on biophysical assessments
Authors: Grove Gary , Houser Timothy , Dove Jacob , Moody Derek
Published: November 2022

Background

Medical Adhesive Related Skin Injuries can arise from topically applied medical devices, especially in those with fragile skin, including the elderly and premature infants. The purpose of this study was to compare gentleness and reapplication of two pulse oximetry sensors (OxySoftN and MaxN, Medtronic, Boulder, CO).

Materials and methods

Eighteen healthy subjects aged 65 years and older were enrolled in the gentleness trial, and 20 healthy subjects (18–69 years) were enrolled in the reapplication trial. For the gentleness trial, trans‐epidermal water loss (TEWL) measurements were made at five sites on each forearm at three time points (baseline [T0], 4‐h postinitial wear [T1], 4‐h postsecond wear [T2]). Total amount of protein adhered to each device was also determined. For the reapplication trial, a series of 180° peel tests were performed to observe the forces required to detach the sensor from the skin.

Results

TEWL rates in the tail region were significantly greater with MaxN compared to OxySoftN at T1 (p < 0.05). Both were significantly greater than control (p < 0.05). Further, protein analysis revealed that the amount of protein removed was significantly less with OxySoftN compared to MaxN (p < < 0.0001). Differences in loss of adhesion of the tail region between the two sensors were demonstrated, with OxySoftN depreciating at a much slower rate compared with MaxN.

Conclusion

The OxySoftN sensor appears to be gentle, even on fragile skin, based on reduced strain on the skin during removal. Further, it demonstrated the ability to withstand several reapplications without functional loss in adhesion.
Detection of skin thickness and density in healthy Chinese people by using high‐frequency ultrasound
Authors: Wang Shangshang , Yu Rui‐Xing , Fan Wen , Li Cheng‐Xu , Fei Wen‐Min , Li Shanshan , Zhou Junfeng , Hu Ruiming , Liu Mengguo , Xu Feng , Xu Jinhua , Cui Yong
Published: November 2022

Objectives

Due to a recent development of high‐frequency ultrasound (HFUS) systems, it is easier to realize high‐resolution in vivo imaging of the biological tissues. The object of this study was to map the thickness and echo density of skin layers in healthy Chinese people and assess the influence of gender, age, and region on it.

Methods

A total of 189 volunteers (85 male, 104 female) with age range of 22–75‐year old (mean age of 41.2‐year old) were enrolled. The thickness and density of the epidermis and dermis layer were detected by high‐frequency (22 or 75 MHz) ultrasonography at 13 different anatomical sites, including the forehead, cheeks, flexor and extensor forearms, flexor and extensor upper arms, inner and outer legs, inner and outer thighs, back, and abdomen.

Results

The thickness and density of epidermis/dermis between different anatomical sites were statistically significant (p < 0.05). The epidermis thickness of the face and trunk were less than that of the limbs, whereas the thicknesses of the dermis were on the contrary. The density of the epidermis/dermis of the face and trunk were less than that of the limbs. The thickness of dermis in most of the sites were higher in male than in female, and the density of epidermis and dermis in most of the sites were less in men than in women. The thicknesses/densities of dermis were lower in older age group in almost all sites, whereas only several sites reached statistical. The difference between the north and south regions showed the environment also influenced the thickness and density of the skin.

Conclusion

HFUS provides a simple noninvasive method for evaluating the skin thickness and echo‐density, which, reflecting intradermal structure, exhibit systematic regional variation. With the establishment of Chinese phenotypic database of skin thickness and density, it will be helpful for the skin disease assessment, skin surgery, and cosmetology technology.
Inference for log‐location‐scale family of distributions under competing risks with progressive type‐I interval censored data
Authors: Roy Soumya , Pradhan Biswabrata
Published: November 2022

In this article, we present statistical inference of unknown lifetime parameters based on a progressive Type‐I interval censored dataset in presence of independent competing risks. A progressive Type‐I interval censoring scheme is a generalization of an interval censoring scheme, allowing intermediate withdrawals of test units at the inspection points. We assume that the lifetime distribution corresponding to a failure mode belongs to a log‐location‐scale family of distributions. Subsequently, we present the maximum likelihood analysis for unknown model parameters. We observe that the numerical computation of the maximum likelihood estimates can be significantly eased by developing an expectation‐maximization algorithm. We demonstrate the same for three popular choices of the log‐location‐scale family of distributions. We then provide Bayesian inference of the unknown lifetime parameters via Gibbs Sampling and a related data augmentation scheme. We compare the performance of the maximum likelihood estimators and Bayesian estimators using a detailed simulation study. We also illustrate the developed methods using a progressive Type‐I interval censored dataset.
Predicting the short‐ and long‐term effects of recycling organic wastes in cropping systems with the PROLEG tool
Authors: Levavasseur Florent , Houot Sabine
Published: November 2022

Recycling organic wastes (OWs) in agriculture may increase soil organic carbon (SOC), improve soil chemical, physical and biological properties and make mineral fertilizer savings possible. Some drawbacks are related, for example, to N losses, soil contamination or greenhouse gas (GHG) emissions, and may counterbalance the interest in OW recycling. Some of these effects are only noticeable after repeated applications over several years and depend on OW type, on their insertion in cropping systems (e.g. rate, period) and on pedoclimatic conditions. The optimization of OW recycling should promote its positive effects and limit its negative effects. Various simulation tools can predict some OW effects and help with this optimization. However, despite many existing tools, dedicated tools with a multicriteria approach to OW effects and the ability to consider various OWs, soils, climates and cropping systems are still missing. We developed the PROLEG tool to predict the short‐ and long‐term multiple effects of OW application in agriculture at the field scale. The tool combined the soil‐carbon model AMG to predict SOC changes, the soil‐crop model STICS to predict N supply and N losses, some pedotransfer functions to predict the evolution of some soil properties related to SOC and simple balance equations to predict mineral fertilizer needs, GHG balance, soil contamination with trace metals and economic results. The tool also embedded many parameter tables, especially related to the characteristics of diverse OWs. The tool required easily accessible soil properties and a description of the cropping systems in a simple spreadsheet. It automatically computed mean and detailed output variables in tables and figures. We illustrated the use of the tool with a simple case study. The tool has already been used with farmers to design new cropping systems and to support public policy related to anaerobic digestion.
Kato–Ponce estimates for fractional sublaplacians in the Heisenberg group
Authors: Fanelli Luca , Roncal Luz
Published: November 2022

We give a proof of commutator estimates for fractional powers of the sublaplacian on the Heisenberg group. Our approach is based on pointwise and estimates involving square fractional integrals and Littlewood–Paley square functions.
Aerodynamic Damping of Last Stage Rotating Blades of Low Pressure Steam Turbine Determined From Vibration Test Data
Authors: Doll Philipp , Winkelmann Stefan , Müller Fabian F. , Vogt Damian M. , Aschenbruck Jens
Published: November 2022

In the past, power generation steam turbines were mainly operated at design conditions and at base load. Due to the greater share of fluctuating renewable energy in electricity grids, conventional power plants are increasingly subject to load cycling, which presents higher demands with respect to operational flexibility of turbines. In addition to uncompromised requirements on the efficiency at varying operating conditions, extending the operating range to higher mass flow densities is becoming more important. Often, such developments go beyond existing experience, which necessitates the proper assessment of instability phenomena such as flutter.

Safe operation requires the knowledge of the damping behavior in the entire operating range in order to conclude on the stability of the rotating blades. The aggregate damping consists of mechanical and aerodynamic damping, whereby it is the latter that may lead to an unstable situation.

This paper includes a systematic study on the suitability of various methods for obtaining reliable damping values from experimental test data under realistic operating conditions of steam turbines. In a first step, the influence of different parameters is investigated on a generic ideal signal. Among others, the sensitivity of derived damping values from model parameters is quantified. In a second step, the presented evaluation methods are applied to vibration test data acquired on a free-standing last stage blade row of a scaled steam turbine. The turbine features controlled blade excitation by means of AC electromagnets. The transferability from generic to real signals is analyzed. A robust method is presented to obtain reliable aggregate damping values at various operating conditions from real test data.

For this aggregate damping, the proportion of mechanical and aerodynamic damping is determined by the evaluation of the aggregate damping at several operating points at constant flow rate. This procedure allows to determine the aerodynamic damping of the excited nodal diameters for each operating point. Finally, the experimental aerodynamic damping is compared to data from numerical calculations.
Exploratory Experiments for Simple Approximation of Blade Flutter Aerodynamic Loading Function
Authors: Lepicovsky Jan , Simurda David , Sidlof Petr , Luxa Martin
Published: November 2022

Exploratory experiments to verify a newly proposed simple method determining an approximate form of unsteady blade loading function are described in this paper In this newly proposed approach, a time-dependent blade loading will be substituted for by a series of static loadings acquired for a range of blade incidence angle offsets. The sequence of static loadings will be converted into a time-dependent quasi-dynamic function computationally. In the course of this project a new test facility for forced blade flutter research capable of transonic inlet flow at high oscillation blade frequencies was designed and built at the IT CAS laboratory. A series of test runs simulating blade flutter conditions were carried out for the inlet Mach number range from 0.6 up to 1.09 and blade oscillation frequencies up to 80 Hz. A blade static loading function was created as a pressure difference measured while the blade was not moving and it was set to the outermost incidence angle offsets of plus/minus 1 deg. A blade dynamic loading function was determined as a peak-to-peak amplitude of measured pressure fluctuation while the blade was oscillated at a frequency of 80 Hz. A very good agreement between the measured blade static and blade dynamic loading functions indicates the potentials of the proposed quasi-dynamic method to closely estimate blade loading functions, at least for the reported range of cascade operation conditions.
On the Validity of the Weibull Parameters Used in the Master Curve in Ferritic Steels Containing Notches
Authors: Cicero Sergio , Arrieta Sergio
Published: November 2022

The Master Curve (MC) is a valuable well-known characterization tool of the fracture behaviour of ferritic steels operating within their ductile-to-brittle transition zone (DBTZ). It assumes weakest link statistics in the cleavage process and it is based on a 3 parameter Weibull distribution analysis of the experimental results. Besides, it takes into account the scatter of the fracture resistance, the size effect and the temperature dependence. The methodology has been widely validated and has been standardised in ASTM 1921. This paper analyses whether the Weibull parameters used by the MC, which have been defined and calibrated in cracked conditions, can be applied in ferritic steels containing notches. This would allow the MC to be directly applied in notched conditions. Thus, the different premises sustaining the use of the Master Curve and its 3 Weibull parameters in cracked conditions are summarised, and their corresponding use in notched conditions is subsequently discussed and justified. In addition, some experimental results obtained in two distinct structural steels (S275JR and S690Q) containing different notch radii are utilised in both the analyses of the Weibull parameters and the direct application of the MC in notched conditions. It is observed how the MC provides accurate predictions of the apparent fracture toughness within the DBTZ of the two steels analysed.
Experimental and Numerical Assessment of Weld Residual Stresses in Dissimilar Metal Weld of Reactor Pressure Vessel Nozzles
Authors: Dulieu Pierre , Lacroix Valéry , Mares Vratislav , Arbaoui Larbi , Bournot Jean-Philippe
Published: November 2022

In the Belgian Pressurized Water Reactors Doel 3-4 and Tihange 2-3, the Reactor Pressure Vessel (RPV) nozzle-to-safe-end Dissimilar Metal Welds (DMW) are made of nickel-base alloy 182. This material is known to be susceptible to Primary Water Stress Corrosion Cracking (PWSCC) if the stress level is high enough. In that frame, it is of utmost importance to precisely assess the residual welding stress field. For that purpose, residual stress measurements on a DMW from the cancelled Spanish NPP of Lemoniz are performed with the hole-drilling strain gage method according to ASTM E837. The nozzle-to-safe-end specimen is successively sectioned (machined) from the outside to deduce the residual stress profile through the weld thickness. On the other hand, welding residual stresses in these nozzle-to-safe-end welds are calculated using Finite Element Method. These simulations include the application of buttering, the machining, and the influence of the safe-end-to-piping stainless steel weld. Moreover, the impact of the different steps followed to machine the measured specimen are simulated. The welding heat source as well as some simulation parameters are then calibrated to optimize the match with the experimental data obtained by the described measurement procedure. Based on these results, the plant-specific weld residual stresses are calculated by FE, including partial repairs as well as post-weld heat treatments. These plant specific profiles will be useful to assess the acceptability of flaws that could possibly be detected during In-Service Inspection campaigns and to define reasonable inspection intervals.
Evaluating the Sealing Performance of Engineered PTFE Based Gaskets in Fiberglass Reinforced Plastic Flanges
Authors: Rice Tim , Wilson Jeffery
Published: November 2022

Proper gasket selection for fiberglass reinforced plastic (FRP) flanges is critical to the long-term success of the pipe system. However, very little focus is placed on evaluating the performance of low stress-to-seal, PTFE-based gaskets engineered to perform at the lower bolt loads/gasket stresses allowable on FRP flanges. In cooperation with a premier FRP piping/equipment manufacturer, this paper evaluates and compares the sealing performance of new gasket technologies/designs and commercially available low stress-to-seal, PTFE-based gaskets. To quantify the relative performance, each gasket style was tested to ASTM D5421 “Standard Specification for Contact Molded “Fiberglass” (Glass-Fiber-Reinforced Thermosetting Resin) Flanges”. Gaskets that passed the ASTM D5421 testing were then subjected to a mass leakage test to further classify each gasket style’s sealing/tightness performance. Given the current standard requirements, gaskets that did not pass the ASTM D5421 standard testing were determined not to be suitable for FRP service and thus were not subject to the subsequent mass leakage testing.

By comparing the collected data using these metrics, the final result of this paper will provide end-users with a comprehensive method of evaluating gasket styles and provide guidance for proper gasket selection for FRP flange services.
DetaClad™ Characterization for High-Temperature and High-Pressure Hydrogen Service
Authors: Sarrat Olivier , Prothe Curtis , Delahanty Tim
Published: November 2022

When it comes to considering high-temperature damage mechanisms, one of the most challenging decisions is related to heavy-wall pressure vessels that operate at high pressure and high temperature in a hydrogen containing environment. Hydrotreatment or hydrocracking reactors typically fall under this category and often have an austenitic stainless-steel lining to protect the inner side of the pressure vessel from corrosion. Embrittlement of the carbon steel caused by High-Temperature Hydrogen Attack requires selecting steel with alloying elements such as Cr, Mo and V. The high risks of disbonding of the cladding interface under similar conditions also requires the selection of the most appropriate cladding technology. It is the upmost importance to ensure the interface will support the high-pressure hydrogen and the stresses generated by the heavily loaded internals.

A study around characterizing the DetaClad™ interface was conducted under these extreme operating conditions. More than 150 tests were conducted and coming to the conclusion that DetaClad™ is appropriate for material selection under such demanding operating conditions.
Fracture in the Ductile-To-Brittle Transition Region of A Narrow-Gap Alloy 52 and Alloy 52 Dissimilar Metal Weld With Buttering
Authors: Lindqvist Sebastian , Hytönen Noora , Sirkiä Laura , Arffman Pentti , Lydman Jari , Ge Yanling , Nevasmaa Pekka , Que Zaiqing
Published: November 2022

The fracture toughness in the ductile-to-brittle transition region is determined for the heat-affected zone (HAZ) adjacent to the fusion boundary between a low alloy steel (LAS) and the weld metal of narrow-gap Alloy 52 dissimilar metal weld (DMW) after 15 000 h of thermal aging at 400 °C and of an Alloy 52 DMW with buttering in reference condition. The fracture toughness testing is done according to ASTM E1921, and fractography and cross-section metallography are applied to characterize the crack paths, crack locations and fracture type. The T0 transition temperature for the DMW with buttering is −117 °C, indicating marginally higher toughness compared to the narrow-gap DMW. The cracks close to the fusion boundary (approximately 200 μm) in both DMWs deviate from the HAZ towards the fusion boundary. The thermal aging treatment of the narrow-gap Alloy 52 DMW does not significantly affect the fracture toughness properties of the fusion boundary. Further research is needed to better understand the lower boundary fracture toughness behavior at approximately 300 μm from the fusion boundary. The results contribute to long-term operation assessment of nuclear power plants, and development of analysis and characterization methods for DMWs related to the effect of crack path and location.
Probabilistic Structural Integrity Analysis for Advanced Modular Reactors
Authors: Finley James M. , Cathcart Henry
Published: November 2022

Next-generation Advanced Modular Reactors are expected to aid in the worldwide transition to net-zero emissions. However, these reactors are designed to operate at very high temperatures, which makes the structural integrity of the reactor critical to its design. The structural integrity of previous nuclear reactor designs has been calculated using deterministic methods, but this approach can lead to overly-conservative (or in some cases, optimistic) assessments. Probabilistic structural integrity analysis methods offer the potential to increase understanding of uncertainty and variability in the reactor design, which can reduce design conservatism or increase robustness. Classical Monte-Carlo analysis has been widely used for probabilistic structural integrity analysis, but this approach can be computationally expensive, making it unsuitable for use when iterating and refining reactor designs. This paper assesses alternative probabilistic structural integrity analysis methods, from simple, pseudo-stochastic look-up curve methods to a more complex surrogate Monte-Carlo analysis method using Gaussian process regression. Of the pseudo-stochastic methods, the log-normalized damage margin (LNDM) method is recommended, as it is the most robust, even when used with complex creep laws. The surrogate Monte-Carlo analysis (using a Gaussian process regressor as a surrogate) was found to generate results that were just as accurate and precise as classical Monte-Carlo analysis, but with several orders of magnitude lower computational cost.
Seismic Test Result (Static Load Test) of the Dynamic Functional Demand Valve for Nuclear Power Plant
Authors: Matsubara Yoshinao , Tsutsumi Yoshitaka , Watanabe Urara , Tanemura Shota , Takemoto Yoshiaki
Published: November 2022

The functional maintenance and confirmed acceleration of motor- and air-operated valves in nuclear power plants during an earthquake are regulated in the Japanese seismic design code (JEAC4601 (see Ref. [1])). In the present work, we used a resonant shaking table at the Central Research Institute of the Electric Power Industry (CRIEPI), which is capable of seismic tests at acceleration levels previously unachievable, in seismic tests carried out as high as 20 × 9.8 m/s2 (see Ref. [2] to Ref. [8]). On the other hand, JEAC4601 requires the structural evaluation for the seismic critical parts with allowable stress of 1.5-times yield strength (1.5Sy). In this study, in order to confirm the adequacy of the allowable stress, a static load test equivalent to 1.5Sy and more was conducted for the representative valves, namely, the air-operated globe valve and the air-operated butterfly valve. As a result, we confirmed that the required function of the valves was satisfied.
Flow-Induced Vibration Simulations of a Straight Tube Bundle in Water Cross-Flow, Through URANS Approach
Authors: Vivaldi Daniele , Baccou Jean
Published: November 2022

In the frame of investigating vibration issues that can concern nuclear steam generator U-tubes, coupled fluid-structure numerical simulations could represent a powerful tool. Steam generator tube bundles can be concerned by both turbulence-induced vibrations and fluidelastic instability. In this paper, a single-phase flow is considered and a URANS approach is retained for the fluid modeling. Despite URANS approaches are generally not expected to be able to consistently predict turbulence-induced forces, they could still represent a proper tool to evaluate vortex shedding and fluidelastic instability. The present numerical simulations are performed on an experimental configuration of 7 × 7 straight tube bundle, square pitch, subjected to water cross-flow. Only one tube — the central one — is flexible in both drag and lift directions, all the other tubes being fixed. The structure displacements are taken into account through an ALE approach. 2-way fluid-structure coupling is employed. The goal of the paper is to assess the consistency of FSI numerical simulation for cross-flow configurations, based on fluid URANS approach. To do that, the numerical and experimental results are first compared in terms of vibration response, as a function of the fluid gap velocity. The fluid force cross-correlation and spectrum are then analysed and discussed, in order to understand the behaviour of the URANS approach and the fluid force mechanisms captured.
Overview of Leak-Before-Break Best Practice Document Developed Under the ATLAS+ Project
Authors: Sharples John , Gill Peter , Daniels Brian
Published: November 2022

This paper provides an overview of the Leak-before-Break best practice guidance document that has been produced under the Horizon 2020 project ATLAS+.
Bifurcation Buckling Analysis and Non-Linear Collapse Analysis of Teardrop Shaped Vacuum Chamber
Authors: Jiang Hao , Barbier Charlotte , Riemer Bernie
Published: November 2022

The Spallation Neutron Source (SNS) accelerator is being upgraded to increase the beam power from 1.4MW at 1GeV to 2.8MW at 1.3GeV. The currents in the middle two injection chicane magnets cannot simply be scaled up to accommodate the increased injection energy of 1.3GeV due to potential excessive H− stripping; the magnets must be replaced with longer, lower-field magnets and the associated vacuum chambers need to be redesigned. A new teardrop-shaped vacuum chamber was initially designed to accommodate the new magnets and the updated beam paths and instrumentation. This paper focuses on the structural stability study of the teardrop shape vacuum chamber based on buckling analysis. Protection against collapse from buckling according to the ASME BPVC requirement has been evaluated in depth. First, a Type-1 bifurcation buckling analysis using a linear eigenvalue solution to determine the critical load factor was performed. Subsequently, a Type-3 nonlinear collapse analysis was conducted using the static Riks method with elastic-plastic material properties and imperfections explicitly considered in the model geometry. The critical buckling load for the teardrop shape vacuum chamber was confidently estimated based upon this two-stage approach.
Assessment of the Impact of Elevated Temperature Design Code Revisions on Creep Damage Estimation
Authors: Ando Masanori , Okajima Satoshi , Takasho Hideki
Published: November 2022

Two significant improvements were achieved in 2019 and 2021 Editions of ASME Boiler and Pressure Vessel Code, Section III, Division 5. One is an update of allowable stress values in Gr.91 steel as 9Cr-1Mo-V steel. The time for which the values of Sr, expected minimum stress-to-rupture, is defined were extended from 300,000 to 500,000 hours and the values in relatively high temperature and long-term region were reduced compared with those in the region less than 300,000 hours. The other is that the equations for monotonic stress-strain curves and creep strain curves were provided. These improvements affect the creep damage calculation in the evaluation of creep-fatigue damage. The reduction of Sr values increases creep damage and providing the equations allows calculating the creep damage more precisely. In this study, the impact of these improvements on the creep damage calculation is assessed by some sample problem calculations. The stress dividing coefficient of K′ for Gr.91 was improved from 0.9 in 2017 Edition to 1.0 in 2019 Edition. The effect of the improvement on creep damage was also assessed. The total creep damage almost tripled by using the updated Sr table, although and decreased by about 20% by using the provided equations rather than graphic calculation in a sample problem case. The change of the value of K′ halved the creep damage in the sample problem case. The creep damage calculations during the stress relaxation were based on the Division 5 procedures of HBB T-1433(a) and (b), and these results were compared to a calculated result using creep damage calculation procedure using the elastic follow-up concept adopted in the Japanese elevated temperate design code. Material test results of notched bar specimens are also used for comparison. The calculated result indicated that the procedure using the elastic follow-up concept was comparable to those by HBB T-1433(a) and (b), while calculation using the elastic follow-up concept is easier than that of HBB T-1433(a) and (b).
Disorders in Periodic Support for Pipeline Conveying Fluid
Authors: Zeng Qingna , Wang Donghui , Zang Fenggang , Zhang Yixiong
Published: November 2022

This paper studies the influence of disordered parameters on vibration transmission characteristic of pipeline structure with periodic support. Transverse Band Gap structures (BGs) for perfect period and frequency response function (FRF) for finite periods are investigated and fit well with each other. By introducing a certain degree of uncertainty level, interval method is used to convert uncertain parameter problem into two deterministic models. FRF for near-periodic structure with single disorder and BGs for quasi-periodic structure with multiple disorders are investigated concerning support stiffness and periodic length. The existence of disorders in periodic structure would always reduce the attenuation intensity and interval, and some disturbance would even generate new intermediate attenuation zones. Elastic wave propagation with periodic support is much more sensitive to periodic length rather than support stiffness, as the sensitivity is closely related with attenuation mechanism. Therefore, such defects should be carefully avoided in design and manufacturing this kind of periodic pipeline structures. The work in this paper enriches the stability analysis of the pipeline structure with periodic support, and provides reference for the research of noise and vibration reduction of pipeline system in practical engineering.