bluuebunny/crossref_metadata_2025 huggingface dataset:
Can patients contribute to enhancing the safety and effectiveness of test‐result follow‐up? Qualitative outcomes from a health consumer workshop
Authors: Thomas Judith , Dahm Maria R. , Li Julie , Georgiou Andrew
Published: December 2020

Background

Missed test‐results and failure to follow‐up test‐results are major patient safety concerns. Strategies to improve test‐results management have predominantly focused on clinician‐based interventions, with patients principally involved in studies of test‐result communication preferences, the impact of patient portals or experiences with reporting processes in primary care.

Objective

To identify consumer perspectives and experiences of the challenges they have faced with test‐results management, through consumer participation in qualitative data analysis.

Design and participants

Volunteers (n = 10) were recruited to participate in a health consumer reference group workshop on test‐results management. Prior to the workshop, consumers selected topics for discussion using a preference poll. During the workshop, consumers participated in qualitative data analysis of de‐identified excerpts of previously collected interview data discussing hospital test‐results management. Researchers (n = 5) guided consumers through the analytical process and discussion of themes. Discussions were audio‐recorded and transcribed for qualitative analysis.

Results

Consumer‐selected topics for discussion were ‘Transitions of Care’ and ‘Access’. Consumer data analysis prompted broader discussion including lived experiences. Following the workshop, a second level of content analysis pinpointed issues with implications for patient safety highlighting that consumers were astutely aware of macrolevel ‘Systems Factors’ relating to ‘Emergency Departments’ and the health system, as well as microlevel ‘Patient Factors’ (eg patient preferences and circumstances) which impact a patient's understanding during the ‘Communication’ (clinician to patient/between clinicians) of test‐results ‘Information’ (or lack thereof).

Conclusions

Consumers identified the challenges patients experience with test‐results management, and our findings highlight areas for potential improvement in patient safety.

Patient or public contribution

Ten health consumer volunteers actively participated in the test‐results management data analysis workshop conducted in this study. Two health consumers also volunteered to read and comment on the draft manuscript.
A case study of translanguaging phenomenon in CBI classes in a Chinese university context
Authors: Wang Ping
Published: December 2020

In the past decade, the content‐based instruction (CBI) has become increasingly popular in university English as a Foreign Language (EFL) contexts. After reviewing the concepts of CBI and translanguaging, the present study employs the mixed methods to explore the translanguaging practices in a Chinese university context. To achieve the overall aim of this study, 200 subjects were asked to complete questionnaire surveys. Five content specialists as teachers of CBI classes were observed twice for a collection of translanguaging practices. The conclusion draws on the discussion of the data that translanguaging practices have paramount potentials in CBI programs, which should be clearly aware.
Interdependence of piezoelectric coefficient and film thickness in LiTaO3 cantilevers
Authors: Verma Anjneya , Panayanthatta Namanu , Ichangi Arun , Fischer Thomas , Montes Laurent , Bano Edwige , Mathur Sanjay
Published: December 2020

Electromechanical energy demands on homogenous thick films of piezoceramics with sufficiently large piezoelectric constant and reproducible performance. Single‐phase LiTaO3 films deposited by sol‐gel processing have been fabricated as cantilevers to investigate the interdependence of dielectric and piezoelectric properties as a function of film thickness. Phase pure LiTaO3 films with varying thickness in the range of 2.07‐4.37 µm on stainless steel substrates were obtained after calcination of samples at 650°C. The relative permittivity of optimized spin‐coated films peaked at 479.73 (1 kHz), whereas the piezoelectric coefficient (d33 mode) determined by piezoresponse force microscopy was in the range of 21‐24 pm/V. The effect of poling was studied through the butterfly and phase curves. A figure of merit (FOM) up to 3.29 (10−18 m2/V2) was determined for cantilever devices, which were able to generate a peak‐to‐peak voltage of 0.046‐0.15 V using a 1 MΩ resistor as an impedance load at a fixed acceleration of 1.5 m/s2. While the power density was in the range of ~4‐20 × 10−9 W/m3, which increased with the increasing film thickness. The leakage current density decreased in the range of 4 × 10−5‐6 × 10−7 A/m2 in the same direction. As both ferroelectric and piezoelectric properties of LiTaO3 films are dependent on film thickness, an optimal energy conversion efficiency was obtained for a thickness of ~3 µm. Furthermore, these devices were tested up to a temperature of 150°C for voltage generation. Given the need for lead‐free piezoelectric materials for environmental applications, these LiTaO3 cantilevers are very promising for vibrational energy harvester (VEH) applications especially due to their cost effectiveness, small size, stability at higher temperatures, and repeatable properties, which makes them suitable for MEMS devices for industrial applications.
Medium‐ and long‐term clinical benefits of periodontal regenerative/reconstructive procedures in intrabony defects: Systematic review and network meta‐analysis of randomized controlled clinical studies
Authors: Stavropoulos Andreas , Bertl Kristina , Spineli Loukia M. , Sculean Anton , Cortellini Pierpaolo , Tonetti Maurizio
Published: December 2020

Background

Systematic reviews have established the short‐term improvements of periodontal regenerative/reconstructive procedures compared to conventional surgical treatment in intrabony defects. However, a hierarchy of periodontal regenerative/reconstructive procedures regarding the medium‐ to long‐term results of treatment does not exist.

Aim

To systematically assess the literature to answer the focused question “In periodontitis patients with intrabony defects, what are the medium‐ and long‐term benefits of periodontal regenerative/reconstructive procedures compared with open flap debridement (OFD), in terms of clinical and/or radiographic outcome parameters and tooth retention?”.

Material & Methods

Randomized controlled clinical trials (RCTs), reporting on clinical and/or radiographic outcome parameters of periodontal regenerative/reconstructive procedures ≥3 years post‐operatively, were systematically assessed. Clinical [residual probing pocket depth (PD) and clinical attachment level (CAL) gain, tooth loss] and radiographic [residual defect depth (RDD), bone gain (RBL)] outcome parameters were assessed. Descriptive statistics were calculated, and Bayesian random‐effects network meta‐analyses (NMA) were performed where possible.

Results

Thirty RCTs, presenting data 3 to 20 years after treatment with grafting, GTR, EMD, as monotherapies, combinations thereof, and/or adjunctive use of blood‐derived growth factor constructs or with OFD only, were included. NMA based on 21 RCTs showed that OFD was clearly the least efficacious treatment; regenerative/reconstructive treatments resulted in significantly shallower residual PD in 4 out 8 comparisons [range of mean differences (MD): −2.37 to −0.60 mm] and larger CAL gain in 6 out 8 comparisons (range of MD: 1.26 to 2.66 mm), and combination approaches appeared as the most efficacious. Tooth loss after regenerative/reconstructive treatment was less frequent (0.4%) compared to OFD (2.8%), but the evidence was sparse. There were only sparse radiographic data not allowing any relevant comparisons.

Conclusion

Periodontal regenerative/reconstructive therapy in intrabony defects results, in general, in shallower residual PD and larger CAL gain compared with OFD, translating in high rates of tooth survival, on a medium (3–5 years) to long‐term basis (5–20 years). Combination approaches appear, in general, more efficacious compared to monotherapy in terms of shallower residual PD and larger CAL gain. A clear hierarchy could, however, not be established due to limited evidence.
Description and etiology of paleopathological lesions in the type specimen of Parasaurolophus walkeri (Dinosauria: Hadrosauridae), with proposed reconstructions of the nuchal ligament
Authors: Bertozzo Filippo , Manucci Fabio , Dempsey Matthew , Tanke Darren H. , Evans David C. , Ruffell Alastair , Murphy Eileen
Published: December 2020

Paleopathology, or the study of ancient injuries and diseases, can enable the ecology and life history of extinct taxa to be deciphered. Large‐bodied ornithopods are the dinosaurs with the highest frequencies of paleopathology reported to‐date. Among these, the crested hadrosaurid Parasaurolophus walkeri is one of the most famous, largely due to its dramatic elongated and tubular nasal crest. The holotype of Parasaurolophus walkeri at the Royal Ontario Museum, Canada, displays several paleopathologies that have not been discussed in detail previously: a dental lesion in the left maxilla, perhaps related to periodontal disease; callus formation associated with fractures in three dorsal ribs; a discoidal overgrowth above dorsal neural spines six and seven; a cranially oriented spine in dorsal seven, that merges distally with spine six; a V‐shaped gap between dorsal spines seven and eight; and a ventral projection of the pubic process of the ilium which covers, and is fused with, the lateral side of the iliac process of the pubis. These lesions suggest that the animal suffered from one or more traumatic events, with the main one causing a suite of injuries to the anterior aspect of the thorax. The presence of several lesions in a single individual is a rare observation and, in comparison with a substantial database of hadrosaur paleopathological lesions, has the potential to reveal new information about the biology and behavior of these ornithopods. The precise etiology of the iliac abnormality is still unclear, although it is thought to have been an indirect consequence of the anterior trauma. The discoidal overgrowth above the two neural spines also seems to be secondary to the severe trauma inflicted on the ribs and dorsal spines, and probably represents post‐traumatic ossification of the base of the nuchal ligament. The existence of this structure has previously been considered in hadrosaurs and dinosaurs more generally through comparison of origin and insertion sites in modern diapsids (Rhea americana, Alligator mississippiensis, Iguana iguana), but its presence, structure, and origin‐attachment sites are still debated. The V‐shaped gap is hypothesized as representing the point between the stresses of the nuchal ligament, pulling the anterior neural spines forward, and the ossified tendons pulling the posterior neural spines backward. Different reconstructions of the morphology of the structure based on the pathological conditions affecting the neural spines of ROM 768 are proposed. Finally, we review the history of reconstructions for Parasaurolophus walkeri showing how erroneous misconceptions have been perpetuated over time or have led to the development of new hypotheses, including the wide neck model supported in the current research.
Dispersal and recruitment limitations in secondary forests
Authors: Palma Ana C. , Goosem Miriam , Fensham Roderick J. , Goosem Steve , Preece Noel D. , Stevenson Pablo R. , Laurance Susan G. W.
Published: December 2020

Aims

Secondary forests are expanding rapidly in tropical regions and could play an important role in conserving native biodiversity and stabilising global climate. The recovery rate of plant communities in secondary forests varies considerably due to mechanisms associated with seed dispersal and recruitment dynamics. We explored these mechanisms along a chronosequence of tropical secondary forests in an agricultural landscape that was extensively cleared.

Location

We explored these mechanisms along a chronosequence of secondary forests in tropical Australia.

Methods

We used selected plant traits to characterise plant species and compared community composition between demographic stages (i.e. soil seedbank, understorey and overstorey) and forest age categories. We collected soil samples to assess seedbank composition and used quadrants and transects to assess understorey and overstorey plant community composition at each site.

Results

For all demographic stages, we found that young (4‐12 years) and intermediate‐aged forests (16‐20 years) were dominated by early successional, small‐seeded species and traits associated with disturbed forests. In old secondary forest (23‐34 years) some traits associated with late successional stages were present (e.g. large seeds, trees). However, the traits and species composition of mature forests remained distinct from all secondary forests. Across the chronosequence, forest age and demographic stage were significant factors in discriminating species and trait composition between forest sites. We found clear plant community similarities within demographic stages, despite the forest age differences. This suggests stronger limitations to dispersal and recruitment between demographic stages than between forest ages.

Conclusions

Our results show that secondary forests in this region assemble slowly with dispersal and recruitment limitations constraining their recovery. Although a successional transition in species and plant traits composition along the chronosequence is clear, similarities to mature forests remain low. The slow recovery of late successional and large‐seeded species in these secondary forests suggests that active restoration of such species may be necessary if we want to enhance the capacity of these forests to conserve native biodiversity.
Antigenic variation of SARS‐CoV‐2 in response to immune pressure
Authors: Forni Diego , Cagliani Rachele , Pontremoli Chiara , Mozzi Alessandra , Pozzoli Uberto , Clerici Mario , Sironi Manuela
Published: December 2020

Analysis of the bat viruses most closely related to SARS‐CoV‐2 indicated that the virus probably required limited adaptation to spread in humans. Nonetheless, since its introduction in human populations, SARS‐CoV‐2 must have been subject to the selective pressure imposed by the human immune system. We exploited the availability of a large number of high‐quality SARS‐CoV‐2 genomes, as well as of validated epitope predictions, to show that B cell epitopes in the spike glycoprotein (S) and in the nucleocapsid protein (N) have higher diversity than nonepitope positions. Similar results were obtained for other human coronaviruses and for sarbecoviruses sampled in bats. Conversely, in the SARS‐CoV‐2 population, epitopes for CD4+ and CD8+ T cells were not more variable than nonepitope positions. A significant reduction in epitope variability was instead observed for some of the most immunogenic proteins (S, N, ORF8 and ORF3a). Analysis over longer evolutionary time frames indicated that this effect is not due to differential constraints. These data indicate that SARS‐CoV‐2 evolves to elude the host humoral immune response, whereas recognition by T cells is not actively avoided by the virus. However, we also found a trend of lower diversity of T cell epitopes for common cold coronaviruses, indicating that epitope conservation per se is not directly linked to disease severity. We suggest that conservation serves to maintain epitopes that elicit tolerizing T cell responses or induce T cells with regulatory activity.
Fieldwork Protocols for Anthropological Research in Mexico: Permissions and Dissemination
Authors: Rees Martha W.
Published: December 2020

The context of Mexican anthropology affects their institutional and ethical research protocols, and in turn, this context affects how foreign researchers should comply with these, in addition to the codes of their home professional associations and funders. This article examines research permissions and dissemination of results and products, in terms of Mexican protocols and the American Anthropological Association's Code of Ethics, using examples from U.S. and Mexican field research. The objective is to promote greater collaboration, mutual respect, and dissemination, while recognizing the obstacles that different conceptual, professional, and funding frameworks present.
Dopamine and ghrelin receptor co‐expression and interaction in the spinal defecation centers
Authors: Furness John B. , Pustovit Ruslan V. , Syder Andrew J. , Ringuet Mitchell T. , Yoo Eun Ji , Fanjul Andrea , Wykosky Jill , Fothergill Linda J. , Whitfield Emily A. , Furness Sebastian G. B.
Published: December 2020

Background

Dopamine receptor 2 (DRD2) and ghrelin receptor (GHSR1a) agonists both stimulate defecation by actions at the lumbosacral defecation center. Dopamine is in nerve terminals surrounding autonomic neurons of the defecation center, whereas ghrelin is not present in the spinal cord. Dopamine at D2 receptors generally inhibits neurons, but at the defecation center, its effect is excitatory.

Methods

In vivo recording of defecation and colorectal propulsion was used to investigate interaction between DRD2 and GHSR1a. Localization studies were used to determine sites of receptor expression in rat and human spinal cord.

Key Results

Dopamine, and the DRD2 agonist, quinpirole, directly applied to the lumbosacral cord, caused defecation. The effect of intrathecal dopamine was inhibited by the GHSR1a antagonist, YIL781, given systemically, but YIL781 was not an antagonist at DRD2. The DRD2 agonist, pramipexole, administered systemically caused colorectal propulsion that was prevented when the pelvic nerves were cut. Drd2 and Ghsr were expressed together in autonomic preganglionic neurons at the level of the defecation centers in rat and human. Behaviorally induced defecation (caused by water avoidance stress) was reduced by the DRD2 antagonist, sulpiride. We had previously shown it is reduced by YIL781.

Conclusions and Inferences

Our observations imply that dopamine is a transmitter of the defecation pathways whose actions are exerted through interacting dopamine (D2) and ghrelin receptors on lumbosacral autonomic neurons that project to the colorectum. The results explain the excitation by dopamine agonists and the conservation of GHSR1a in the absence of ghrelin.
Serum brain‐derived neurotrophic factor in the diagnosis of febrile seizure
Authors: Cokyaman Turgay , Kasap Tolga , Şehitoğlu Hilal
Published: December 2020

Background

Brain‐derived neurotrophic factor (BDNF) is a noncovalently linked homodimer protein from the neurotrophic growth factor family. Although it is expressed throughout the brain, it is produced more intensively in the entorhinal cortex and hippocampus and can cross the blood‐brain barrier in two directions easily. The aim of this study is to understand, for the first time, whether there is a relationship between febrile seizure (FS) and BDNF.

Methods

The study included cases diagnosed with FS and febrile illness, of similar age, weight, and height, between 6 months and 6 years. Samples for serum BDNF measurement were taken within the first 24–48 h of admission at the hospital and levels were measured using the commercial enzyme‐linked immunosorbent assay kit and expressed in ng/mL.

Results

Eighty cases (40 FS, 40 febrile illness) were included in the study. The mean serum BDNF was found to be 6.7 ± 2.4 ng/mL in the FS group and 4.5 ± 2.6 ng/mL in the febrile illness group (P = 0.001). No relation was found between gender, age, body weight, length, and platelet counts and serum BDNF levels. The optimal cut‐off value for serum BDNF was found to be 5.2 ng/mL (75% sensitivity, 62.5% specificity, AUC: 0.723) to distinguish between FS and febrile illness.

Conclusions

Excluding demographic variables such as gender, age, weight, length, and platelet counts serum BDNF levels have increased in children with FS. Considering the hippocampal origin of FS, we can suggest that the pathophysiology of FS may be related to the BDNF.
Combining favorability modeling with collaborative geo‐visual analysis to improve agricultural pest management
Authors: García‐Chapeton Gustavo Adolfo , Toxopeus Albertus G. , Olivero Jesús , Ostermann Frank O. , de By Rolf A.
Published: December 2020

In this article, we explore the potential of combining favorability modeling with collaborative geo‐visual analysis to determine when and where to apply countermeasures for the olive fruit fly. The favorability function estimates locations and times at which the conditions favor a species exceeding acceptable abundance levels, thus becoming a pest. We built two models based on monitoring data for the olive fruit fly in Andalusia, Spain. The models were used in a geo‐visual analytics prototype to produce map series for the seasons 2012 to 2018, and to explore the models’ outputs collaboratively with stakeholders. Results showed that the models capture known species’ dynamics, but tend to overpredict favorable conditions for pest development. Discussions with stakeholders indicate that the prototype facilitates the communication and discussion of modeling results between researchers, authorities, and field technicians, which also enables a better understanding of the pest dynamics, and the planning and execution of control activities.
Use of Average Temperature in Fen Calculations
Authors: Weitze W. F.
Published: December 2020

The effect of the light reactor water environment on fatigue damage is referred to as environmentally assisted fatigue (EAF). This effect is accounted for by applying an environmental fatigue correction factor, Fen, to calculated fatigue usage. In providing guidelines for calculation of Fen, Revision 0 of NUREG/CR-6909 [1] permits temperature averaging for the case of a constant strain rate and linear temperature response, and permits it in other cases as well, but only if the average temperature used produces results that are consistent with the modified rate approach [1, p. A.5]. Revision 1 of NUREG/CR-6909 [2] modifies this slightly, requiring that the threshold temperature be used in averaging instead of the minimum if the minimum is below the threshold [2, p. A-6]. In both cases, the benchmark for accuracy is the modified rate approach [2, Section 4.4].

In this paper, we use real world examples to compare Fen values based on the modified rate approach with those using average strain rate and temperature. We also examine how to select the rise time used to calculate average strain rate in those cases where it is not obvious. We find that temperature averaging is conservative if rise time and other parameters are correctly selected.
Assessment of the Continued Need for Independent Requirements on Transition Temperature and Upper Shelf Charpy Impact Toughness Metrics in Regulations Pertaining to Nuclear Reactor Pressure Vessels
Authors: Kirk Mark , Yamamoto Masato , Erickson Marjorie
Published: December 2020

The toughness requirements for the ferritic steels used to construct the primary pressure boundary of a nuclear power plant include both transition temperature metrics as well as upper-shelf metrics. These separate specifications for transition and upper shelf toughness find their origins in decisions made during the 1970s and 1980s, a time when there was much less empirical and theoretical knowledge concerning the relationship between these quantities. Currently, significant evidence exists to demonstrate a systematic relationship between transition and upper shelf toughness metrics for RPV-grade steels and weldments (e.g., the equations in draft Code Case N-830-1, empirical correlation between Charpy transition temperature and upper shelf metrics, etc.). This paper explores these relationships and demonstrates that, in many cases, the joint specification of transition temperature and upper shelf toughness values is redundant and, therefore, unnecessary.
Methods to Appropriately Account for Uncertainties in Structural Integrity Assessment Models
Authors: Erickson Marjorie , Kirk Mark
Published: December 2020

To ensure an appropriate and/or conservative assessment of structural integrity it is essential to account for the uncertainties inherent to the various inputs and models that, collectively, contribute to a structural integrity assessment. While the methods used to account for uncertainties will differ, this applies equally to assessments performed using either deterministic or probabilistic approaches. Oftentimes the overall model used for a structural integrity assessment is itself comprised of multiple inputs and models, which themselves may be inter-related and/or correlated. In these circumstances the quest to ensure that all uncertainties are addressed can result in the same uncertainty — or uncertainty source — being accounted for multiple times. Such “double-counting” of uncertainties introduces un-needed conservatism to the assessment and should be avoided.

In this paper we use the linked fracture toughness models contained in the recently proposed Revision 1 to ASME Section XI Code Case N-830 to provide examples of uncertainty treatment in analyses using multiple models. Identification of sources of uncertainty in each model used in a multi-model analysis can help to ensure that each source is accounted for appropriately and not multiple times. The CC N-830-1 models are used to demonstrate the effects of various uncertainty treatment strategies and the pitfalls that arise from treating sources of uncertainty twice.
Evaluation of Nozzle P-T Limit Curves for Korea Optimized Power Reactor
Authors: Lee Hyunchul , Yoo Choonsung , Maeng Youngjae , Yoo Sunghoon
Published: December 2020

The purpose of the Pressure – Temperature (P-T) limit curve is to prevent a failure of reactor pressure vessel during operation of reactor coolant system. In Korea, P-T limit curves have to meet 10CFR50 Appendix G [1] according to Nuclear Safety and Security Commission Notification 2017-20. The P-T limit curves have been traditionally evaluated based on the beltline region which is most affected by neutron irradiation. However due to the geometric discontinuity, the inside corner regions of the vessel nozzles are the most highly stressed regions of reactor vessel. These higher stresses can potentially result in more restrictive P-T limits, even if the reference nil ductility transition temperatures (RTNDT) for these components are not as high as those of the reactor vessel beltline shell materials that have simpler geometries. In 2014, the NRC issued Regulatory Issue Summary (RIS) 2014-11 [2], which require the consideration of reactor vessel nozzles in P-T limits curve generation.

In this paper, P-T limit curves for Korea optimized power reactor (OPR-1000) nozzles at the end of license were evaluated. And then these curves were compared to the traditional beltline region P-T limit curves in order to verify which curve is more limiting.
Treatment of the Interaction With the Free Surface of the Component for Combined Subsurface Flaws: Technical Basis for Revision of IWA-3300 and Table IWB/IWC-3510-1
Authors: Lacroix Valéry , Dulieu Pierre , Hasegawa Kunio , Mares Vratislav
Published: December 2020

When flaws are detected in pressure retaining components, assessments have to be done in order to demonstrate the fitness-for-service (FFS) of the component for continued operation. This FFS demonstration is performed in accordance with FFS Codes providing flaw assessment procedures and acceptance standards. Before performing analyses, a flaw characterization has to be carried out in order to determine unequivocally the flaw geometry. This flaw characterization is done according to rules provided in the FFS Codes and hence appears as crucial for the rest of the flaw assessment.

The first step of the flaw characterization addresses the interaction of the flaw and the free surface of the component: if a subsurface flaw is located near the free surface, this step consists of characterizing the flaw as surface or subsurface according to subsurface-to-surface flaw proximity rules. The recharacterization process from subsurface to surface flaw is addressed in all fitness-for-service (FFS) Codes. The second step of the flaw characterization addresses the interaction of the flaw with adjacent flaws: if a flaw is located near another flaw, this step consists of combining the flaws between them according to flaw proximity rules.

However, in some FFS Codes and in the ASME B&PV Section XI Code particularly, there is a lack on how to treat the interaction of a combined flaw and the free surface of the component. The ASME B&PV Section XI Code flaw characterization is not clear on this topic which could lead to misinterpretations and unreliable flaw assessment results.

Some typical examples of unrealistic flaw assessment results due to these misinterpretations of the ASME B&PV Code Section XI flaw characterization rules are depicted in this paper. After analyzing more in-depth the origin of the inconsistencies based on 3D Extended Finite Element Method (XFEM) calculations, the paper is used as Technical Basis for the improvement of the ASME B&PV Code Section XI in order to clarify the treatment of combined flaw in the flaw characterization (IWA-3300) and in the flaw acceptability assessment as well (IWB/IWC-3510-1).
A Comparison of Stress Intensity Factor Solutions for Surface Cracked Plates
Authors: Aird C. J.
Published: December 2020

The present paper compares the stress intensity factor (SIF) solutions for surface-cracked plates presented in R6, BS 7910, API 579-1/ASME FFS-1 and RSE-M. Both extended surface cracks and semi-elliptical surface cracks are considered. In general, the agreement between the various solutions is found to be good at within 5%. However, particular cases are highlighted which are associated with larger differences between the SIFs. For extended surface cracks, the various solutions agree closely at within 5% in all but one case. For semi-elliptical surface cracks, the agreement between the various solutions is generally better at the deepest point than at the so-called ‘surface’ points. In particular, the surface point SIFs corresponding to the Vainshtok and Varfolomeyev weight function solution which appears in API-579-1/ASME FFS-1 differ significantly from the other solutions in some cases. It is concluded that further work is required in order to establish an appropriate definition of the surface point SIF for use in structural integrity calculations.
Development of Design Method for High Temperature Nuclear Reactor Cladded Components
Authors: Barua B. , Messner M. C. , Jetter R. I. , Sham T.-L.
Published: December 2020

High temperature nuclear reactors plan to use highly corrosive coolant such as molten salts, molten lead, and lead-bismuth eutectic mixtures. The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors are not ideal for resisting corrosion when exposed to these coolants. One option to overcome this limitation would be to Code-qualify new corrosion-resistant materials for Class A service, however this process is long and expensive and requires long-term creep test data. A near-term alternative would be to allow designers to clad the existing Class A base materials with non-qualified corrosion-resistant materials. However, there are currently no ASME design rules for cladded components to guard against creepfatigue failure and ratcheting strain accumulation in elevated temperature nuclear service. This work addresses this deficiency by proposing a design strategy for cladded components that does not require long-term testing of clad materials. The proposed approach relies on approximate design analysis methods for two types of clad materials — soft clad that creeps faster than the base material and hard clad that creeps slower and has higher yield stress than the base material. The proposed approach treats a soft clad material as perfectly compliant and a hard clad material as linear elastic. Sample finite element analyses of representative high temperature reactor components are performed to verify the approach. At the end, a complete set of design rules is provided for each of the two types of cladded components.
Application of Environmentally Assisted Fatigue Transient Ramp Times Optimization in Design Evaluations and Fatigue Monitoring Algorithms
Authors: Matthews Eric , Gray Mark
Published: December 2020

As part of the effort for a nuclear plant to undergo license renewal, the effect of reactor water environment on fatigue life must be addressed for limiting component locations. One method to incorporate the effects of reactor water environment into the fatigue evaluations of metal components is to apply an environmental fatigue penalty factor (Fen) to the partial usage factor obtained from the design fatigue curve for each stress cycle. Fatigue evaluations have historically been performed by assuming that temperature transient loads occur at conservatively high rates to maximize the stress response and corresponding fatigue usage values. However, with consideration of reactor water environmental effects on fatigue, transients with slower rates generally produce higher Fen values that could potentially result in higher environmental fatigue usage values than transients with identical temperature changes but faster rates. A generic parametric study was performed in MRP-218 to characterize limiting transient ramp rates with respect to environmental fatigue usage for a range of piping geometry and material configurations. This paper describes the application of the parametric study results to optimize thermal hydraulic and stress response modeling assumptions with respect to transient rates and downstream effects on environmental fatigue results in both design and monitoring fatigue evaluations.
Local Failure Analysis of Bolted Flanges
Authors: Li Qi , Sulwinski Rafal , Boellstorff Charles
Published: December 2020

Protection against local failure is one of the integral components in the design-by-analysis requirements in ASME BPVC Section VIII, Division 2. Of the methods offered by the ASME, the Local Strain Limit procedure outlined in 5.3.3.1 is the typical calculation method. However, it has been found that relying on this procedure alone can lead to untenable utilization results if used on certain analyses with varied load paths.

The flange described in this study was calculated using “design by analysis” according to Part 5 of ASME BPVC Section VIII, Division 2. The elastic-plastic stress analysis method was used. The flange was loaded with an initial bolt pre-tension and then with internal pressure. During the local failure calculation, an abnormal condition was encountered in the form of a large spike in the history curve of the ratio between plastic strain and limiting triaxial strain.

An investigation found that despite being in a stress state below yield stress, some nodes had a non-zero plastic strain and high triaxiality factor. This was caused by the load sequence: first, the bolt pre-tension and then internal pressure. The flange was first bent due to the pre-tension load, and later experienced bending in the opposite direction after the internal pressure load was applied. This resulted in a relatively low stress state with a high triaxiality factor and non-zero plastic strain in certain areas, which then showed high utilization under the local failure strain limit criterion.

This paper will discuss how this issue can be avoided by using the strain limit damage calculation procedure 5.3.3.2 outlined in ASME BPVC Section VIII, Division 2.
Codes and Standards for Managing Degradation of Boilers in Service
Authors: Delle Site Corrado , Artenio Emanuele , Sepede Gennaro , Chini Matteo , Giacobbe Francesco
Published: December 2020

Degradation of pressure equipment is becoming an important issue due to increasing asset service time in process and power plants across Europe. For this reason it is important to assess life consumption of these assets to avoid catastrophic failures. Therefore it is necessary to refer to national/international normative on this subject. At present time the Italian thermotechnical committee (CTI) has drawn up a comprehensive set of norms which help the user to set up an inspection plan to investigate and assess degradation of pressure vessels and boilers. In the first part of this paper creep damage of Steam Generators is analyzed. For this purpose results of INAIL (Istituto Nazionale per l’ Assicurazione contro gli Infortuni sul Lavoro) database of steam boilers with 100’000 service hours or more is illustrated. Critical components are identified with reference to materials, geometry and operating parameters (pressure, temperature and time). At the end of the design life cycle, components of pressure equipment operated in creep regime must subjected to specific checks to estimate their residual life and the suitability for further use in safety conditions. The procedure allows to define reinspection intervals keeping acceptable the risk associated with the further use of the component related to creep even in evidence of defects in progress. The first check must be performed after 100,000 hours of effective use. Then, residual life evaluations must be repeated according to period of time that are defined as function of the results of all the checks carried out. In the second part of this paper boiler degradation is discussed with reference to NDT results and in-field inspection campaigns which are carried out traditionally after 45 years of service time, to minimize the risk of pressure components failures. In this paper results of different case studies are discussed with reference to degradation mechanisms and applicable standards.
Overview of EASICS Validation Experiments and Code Comparison of R5, RCC-MRX and ASME III Division V
Authors: James Peter , Coon David , Austin Colin , Underwood Nicholas , Chevalier Marc , Dean David
Published: December 2020

The “Establishing AMR Structural Integrity Codes and Standards for UK GDA” (EASICS) project has recently been established to help support the acceptance of Advanced Modular Reactors, or AMRs, which are typically based on high temperature Generation IV reactors. The EASICS project is looking to help define the requirements for codes and standards for the design of AMRs, to ensure that state-of-the art knowledge will be brought to bear on developing the required design and assessment methodologies. The EASICS project is to run from July 2019 to March 2021.

To support this, the work presented in this paper provides an overview of two interacting aspects of this programme. The first is to perform validation tests for high temperature creep-fatigue assessments of a plant relevant component. The second aspect is to use these results, along with those of other identified tests, to provide a comparison of internationally recognised approaches for the assessment of high temperature (creep regime) components. This paper provides an initial overview of the works and progress; the final results will be presented in subsequent paper(s).

Specialist testing of a plant relevant component (thin tubes butt welded together) under high temperature loading conditions will be performed. The validation testing is to include two fatigue tests and four creep-fatigue tests on 316H welded tubes. The tubes will be subject to strain controlled tension/compression (R-ratio of −1), with the possibility to apply a displacement controlled dwell. The tests will be conducted at 525 C.

To help enhance interaction with the code bodies, and to understand the impact of differences in the approaches, comparative assessments will be performed when adopting R5, ASME Section III Div 5 and RCC-MRx. One comparison will be based around the tests detailed here. The second assessment comparison will consider the Evasion mock-up tests provided by CEA (sodium based thermal shock tests). The third assessment case currently still needs to be defined in the programme at the time of writing. The subsequent discussions over results, differences and potential impact to the codes will help inform a guidance document to best assess AMRs in the UK.
Probabilistic Leak Before Break Using the R6 Methodology
Authors: Gill Peter
Published: December 2020

The integrity of a component in a safety critical industry is determined by carrying out Engineering Critical Assessments (ECA). These are designed to provide a conservative estimate of the life of a component based on conservative inputs/methodology. It is becoming increasingly apparent that for many applications these methods are overly conservative. The only physical way to really assess the reliability of a component is by producing many thousands, if not millions of a specific component and calculating a failure probability based on testing/OPEX. This is simply not feasible for the components in, for example, a nuclear reactor, and probabilistic techniques are becoming increasingly important as a means to understand the reliability of a component. This information can then be used to assess risk and inform inspection programmes.

Typically a probabilistic method relies on assigning distributions to various input parameters and evaluating a probability integral, usually by Monte-Carlo analysis. A previous PVP paper developed Monte Carlo methods using the R6 fracture mechanics procedure. Although providing good insight into the likelihood of failure, these analyses were simplified and not readily applied to realistic plant situations. Further development would enable much more of the technology contained within R6 to be applied within probabilistic software. The following new features of the software are presented in this paper:

• the latest K and limit load solutions from R6 for through wall circumferential defects

• Simplified V factor approach to account for secondary stresses

• two phase flow (water) based on the latest SQUIRT methodology

• global bending, through wall bending, weld residual stress

This enables a full probabilistic leak detection calculation for circumferential through wall cracks in pipes. Examples of probabilistic Leak-before-Break calculations for PWR pipework are presented in the paper.
Population Density and Damage Caused by Two Spotted Spider Mite, Tetranychus urticae Koch on Different Pinto Bean Lines Under Field Conditions

Authors: Saeidi Zarir , Babaei Ghobad , Salehi Foroud
Published: December 2020

In this study, population density and yield loss caused by two-spotted spider mite (TSSM) on eight lines of pinto bean were studied under field conditions during two successive years (2009-2010). The experiment was arranged in completely randomized block design with subdivided plots and four replications in Lordegan fields, Chaharmahal va Bakhtiari province, Iran. The main plots and sub-plots consisted of bean lines and acaricides application, respectively. Population density of TSSM was recorded at weekly intervals, beginning from the seedling stage and continued to harvesting time on different lines. Yield loss caused by the mite on each line, was calculated by subtracting the average yields in sprayed subplots versus unsprayed subplots. For this purpose, 10 plants from each subplot were selected randomly and the yield and yield components including; the number of pods/plant, number of seeds/pod and weight of 100 seeds were recorded. Moreover, the grain yield (kg. ha-1) was determined by harvesting the central area (10 m2) in each subplot. Our results indicated significant differences in TSSM population (eggs, juveniles and adults) among the studied lines. In 2009, the highest number of mite was recorded on line ‘L29’ (120.20 ± 18.79) whereas, the lowest on line ‘L1’ (22.51 ± 4.96 mites/ 2 cm2 of the abaxial leaf surface). Moreover, during 2010, the highest and the lowest population density of the mite were supported by line ‘D3’ (55.53 ± 5.68) and line ‘L1’ (9.33 ± 0.79 mites/ 2 cm2 of the abaxial leaf surface), respectively. Mean yield loss of pinto bean lines due to the mite attack calculated 1460.6 kg. ha-1 (64.1 ± 10.2%) and 1278.7 kg. ha-1 (61.4 ± 8.6%) in 2009 and 2010, respectively. The highest grain yield loss presented by line ‘L1’ (91.1 ± 12.1% and 86.4 ± 8.9%) followed by lines ‘L29’and ‘L30’, whereas, the lowest observed in lines ‘J29’ (41.5 ± 7.7% and 37.5 ± 7.6%) and ‘L19’ (50.7 ± 6.6% and 47.4 ± 5.4% in 2009 and 2010, respectively).
Thyreophagus plocepasseri sp. n., a new parthenogenetic species of acarid mites (Acariformes: Acaridae) from Kenya

Authors: Klimov P. B. , Mwangi Edward , Merckx Jonas , Duarte Marcus V. A. , Wäckers Felix L. , Vangansbeke D.
Published: December 2020

To date, some species in the genus Thyreophagus, such as Th. entomophagus and Th. cracentiseta, have been shown to be useful factitious prey for mass-rearing of predacious phytoseiid mites, one of the most common groups of mites used for biological control. Here, we describe a new species, Thyreophagus plocepasseri sp. n. from Kenya that can serve as a factitious prey as well. In addition, the new species is asexual, a trait that can be advantageous for its mass-rearing in industrial settings. In the description, we use high-resolution light microscope imaging and extensive comparison with a similar species, Thyreophagus athiasae, for which the type was studied. We review the literature on asexual acarid mites and point to a lack of data on the presence of sex-manipulating bacteria (Wolbachia, Cardinium) in these asexual mite lineages. Based on the literature, these bacteria are known to induce parthenogenesis in several haplodiploid mites, but they have not been linked so far to parthenogenesis inducement in diplodiploid acarid mites.
Temporal context improves automatic recognition of call sequences in soundscape data
Authors: Madhusudhana Shyam , Shiu Yu , Klinck Holger , Fleishman Erica , Liu Xiaobai , Nosal Eva-Marie , Helble Tyler , Cholewiak Danielle , Gillespie Douglas , Širović Ana , Roch Marie A.
Published: December 2020

Convolutional neural networks (CNNs) are commonly employed for detecting animal vocalizations. We explored whether use of the temporal patterns in song notes can improve recognition. Fin whales (Balaenoptera physalus) produce sequences of low-frequency, down-swept calls (20 Hz pulses) over many minutes. Timing between calls can be exploited to improve detection. We trained a base CNN model to detect 20 Hz pulses in 4 s audio segments. Then, we trained three variants of long short-term memory (LSTM) networks to process sequences produced by the CNN. In the first, the inputs to the LSTM were the scalar prediction scores from the CNN. The second examined sequences of features produced by the CNN before classification. The third combined the feature vectors and scores produced by the CNN. We conducted cross-validation experiments on recordings from the Southern California Bight collected between 2008 and 2014. All three variants outperformed the CNN. The precision-recall (PR) curves of the hybrid models dominated that of the base model, with improvements of 8%–13% in both peak F1-score and area under PR-curve. The second and third hybrid variants performed better than the first. CNN-LSTM hybrid models efficiently improve recognition of call sequences by incorporating temporal context.