bluuebunny/crossref_metadata_2025 huggingface dataset:
The paradox of regulatory discretion
Authors: Mantzari Despoina , Vantaggiato Francesca Pia
Published: October 2020

Regulatory authorities in the utilities sector typically employ economic evidence and analysis to make expert discretionary judgments under uncertainty. However, economic analysis does not provide clear answers regarding policy outcomes. This exposes regulators to environmental uncertainty, that is, uncertainty regarding the reactions of other actors in the institutional system to their decisions. When policy outcome and environmental uncertainty are high, discretion takes center stage. Will regulators pursue the course of action suggested by economic analysis and their expert judgment or not? What explains this choice? To answer these questions, we carry out a comparative analysis of three British regulatory authorities in the utilities sector: the Office of Communications, the Office of Gas and Electricity, and the Water Services Regulation Authority. We consider two key sectoral and organizational characteristics: the extent of market competition, and statutory discretion. We rely on interview evidence and documentary analysis and a principal–agent framework. Our analysis reveals a paradox: when environmental and policy outcome uncertainty are high, the higher the regulatory discretion, the lower the role of economic expertise in regulatory decisions. Our findings call for a normative reflection on the role of expertise in regulated sectors.
Effects of cold physical plasma on oral lichen planus: An in vitro study (Effects of CAP on OLP)
Authors: Seebauer Christian , Freund Eric , Hasse Sybille , Miller Vandana , Segebarth Maria , Lucas Christian , Kindler Stefan , Dieke Tobias , Metelmann Hans‐Robert , Daeschlein Georg , Jesse Katja , Weltmann Klaus‐Dieter , Bekeschus Sander
Published: October 2020

Objectives

In the search for more effective and safe treatment avenues, we investigated cold physical plasma as a new treatment modality for therapy of oral lichen planus (OLP).

Material and Methods

Healthy and diseased human mucosal tissue samples with a size of 3 mm in diameter obtained from OLP patients were subjected to plasma treatment ex vivo or were left untreated. Tissue sections were quantified for immune‐infiltration of CD4+, CD8+, CD45RA+, and CD45R0+ T cells. Moreover, the tissues' inflammatory profile was assessed by analyzing 12 different cytokines in the surrounding media.

Results

A significantly increased infiltrate of CD8+ and CD45‐R0+ T cells was detected in OLP tissue samples when compared to healthy tissue. A higher concentration of interleukin (IL) 1β, IL6, IL8, and granulocyte macrophage‐colony stimulating factor (GM‐CMF) was detected in OLP samples compared to healthy mucosal tissue. For all cytokines and chemokines investigated, 23 out of 24 comparisons showed a decrease in tendency (significant for IL1β, IL2, IL10, and GM‐CSF) in response to plasma treatment. In ex vivo‐treated tissue, a decrease of T‐cell infiltrate in OLP lesions compared with healthy tissue was observed.

Conclusion

Our findings suggest cold physical plasma can be a promising therapeutic option for OLP that requires further validation in vivo.
Prevalence and associated factors of wheeze in early infancy
Authors: Sugiura Shiro , Hiramitsu Yoshimichi , Futamura Masaki , Kamioka Naomi , Yamaguchi Chikae , Umemura Harue , Ito Komei , Camargo Carlos A
Published: October 2020

Background

The aim of this study was to assess the prevalence of wheeze in early childhood and to characterize associated factors for wheeze that could identify potentially feasible interventions for the future prevention of wheeze.

Methods

We performed a cross‐sectional analysis of the data from the International Study of Asthma and Allergies in Childhood (ISAAC)‐modified self‐administered questionnaire of parents of 4‐month‐old infants at well‐child visits (mandatory health check‐ups) in Nagoya City, Japan, between April 2016 and March 2017 (development dataset) and between April 2017 and March 2018 (validation dataset). We used a multivariable, multilevel analysis to identify significant (P < 0.05), associated factors (Bonferroni correction was applied as necessary) after adjustment for local outbreaks of virus‐transmitted diseases, access to medical facilities, and socioeconomic status.

Results

Among the 20 362 questionnaires given to families of infants living in Nagoya City (development dataset), 19 104 questionnaires (93.8%) were analyzed after data cleaning. In all, 1,446 (7.6%) infants experienced wheeze at least once within 4 months of age, 991 (5.2%) visited the clinic/hospital with wheeze, and 244 (1.3%) underwent hospitalization at that time. In the multilevel, multivariable model for hospitalization with wheeze, significant associated factors were male sex (adjusted odds ratio 1.8; 95% confidence interval 1.4–2.3), maternal current smoking (3.3; 2.0–5.5), and having at least one sibling (3.0; 2.2–4.1). These factors were also associated with wheeze and clinic/hospital visit with wheeze, and the results were confirmed in the validation dataset.

Conclusions

Our study highlights that smoking cessation among mothers and improved hand hygiene at home are two interventions that could potentially decrease wheeze in early infancy.
The ratio of vision to data: Promoting emergent science and technologies through promissory regulation, the case of the FDA and personalised medicine
Authors: Hogarth Stuart , Martin Paul
Published: October 2020

Pharmacogenetic tests provide genetic data to tailor drug treatment and were widely predicted to be one of the first fruits of the Human Genome Project. In the mid‐2000s, the US Food and Drugs Administration (FDA) became an advocate for pharmacogenetic testing, but its efforts to build a market for this new technology brought the agency into dispute with other regulatory actors over the type of evidence needed for the adoption of pharmacogenetic testing, in particular the importance of randomized control trials. The warfarin case highlights the tension between a new form of promissory regulation driven by future expectations and FDA's established role as protector of public health; and the controversy can be conceptualized as a struggle over regulatory epistemologies within a complex polycentric regulatory space. Our case study addresses two themes central to the burgeoning scholarship on the governance of emergent science and technologies (EST): the political economy of regulation, in particular the role that regulators play in creating markets for EST; and the epistemological politics of regulatory science, in particular the controversy that arises when regulators modify scientific standards to accommodate EST. Linking these two themes is the concept of promissory regulation: the idea that regulatory policy may be shaped by an institutional commitment to the transformational potential of EST. This concept sheds new light on the neo‐mercantilist nature of contemporary regulatory capitalism.
Dynamic Collaboration: The Effects of External Rules and Collaboration Scope on Interlocal Collaboration
Authors: Youm Jisun , Terman Jessica
Published: October 2020

Governance structures such as the American system of federalism create the incentive structure and framework for collaboration between local governments. This interlocal collaboration is crucial to helping governments deal with contemporary issues such as energy efficiency and climate policy where collective action can solve problems more successfully. The goal of this study is to examine how external rules such as federal grant regulations and the current scope of interlocal collaboration affect the choice of interlocal collaboration over time. We do this in the context of energy efficiency and climate policy using the Energy Efficiency and Conservation Block Grant Program.
Cancer patients’ experiences of realization of relatives’ participation in hospital care: a qualitative interview study
Authors: Lemetti Terhi , Partanen Elli , Hupli Maija , Haavisto Elina
Published: October 2020

Background

Relatives’ participation in the care of patients with cancer in hospital is essential to both patients and relatives. Although the meaning of relatives’ participation has been recognized, knowledge about how patients experience this participation is rare.

Aims

To describe the experiences of patients with cancer of the realization of relatives’ participation in the hospital care.

Materials & Methods

A qualitative study with semi‐structured interviews of patients with cancer (n=21) were conducted. Data was analyzed using inductive thematic analysis.

Results

Three main themes were identified among patients’ experiences: Relative as part of the patient’s care, Relative supporting patient’s coping process, and Hospital enabling or preventing relatives’ participation. The relatives were available for patients in seeking information and in the decision‐making process. They helped with the daily needs of the patient, and supported patients emotionally and by managing everyday life at home. The behavior and attitudes of the healthcare professionals and the special nature of the hospital played a central role in the experiences.

Conclusion

The role of relatives is an important part of the coping process and care of patients with cancer in the hospital.
In vitro thrombus formation and in vivo hemostasis mediated by platelets irradiated with bactericidal ultraviolet C from xenon flash under flow conditions
Authors: Abe Hideki , Endo Kimika , Nogawa Masayuki , Shiba Masayuki , Miyata Shigeki , Satake Masahiro
Published: October 2020

Background

We previously reported a flow path–ultraviolet C (UVC) irradiation system for platelet concentrates (PCs) with platelet additive solution (PAS) to minimize contamination by bacteria. Here, we investigated functionalities of irradiated platelets (PLTs) in in vitro thrombus formation and in vivo hemostasis.

Study Design and Methods

PAS‐PCs were irradiated with flash UVC using the flow path system. Their variables (PLT count, mean platelet volume, pH, glucose, lactate, glycoprotein [GP] Ib, and activated integrin αIIbβ3) were evaluated. Static adhesion to collagen or fibrinogen was analyzed using fluorescent microscopy. Thrombus formation under flow conditions was assessed using a collagen‐coated bead column. Adenosine diphosphate (ADP)‐induced Akt phosphorylation was determined by western blot. In vivo hemostasis and circulatory survival of PLTs were assessed with a rabbit bleeding model.

Results

All variables, except for GPIb expression, were slightly, but significantly, impaired after flash UVC irradiation throughout the 6‐day storage period. No difference was observed in static adhesion to either collagen or fibrinogen between irradiated and nonirradiated PAS‐PCs. In vitro thrombus formation of flash UVC‐irradiated PAS‐PCs was significantly greater than that of nonirradiated PAS‐PCs. ADP‐induced Akt phosphorylation was enhanced in irradiated PAS‐PCs. In vivo hemostatic efficacy was comparable between the groups on Day 1. The efficacy declined in nonirradiated PAS‐PCs on Day 5, while it was retained in flash UVC‐irradiated PAS‐PCs. Circulatory survival of PLTs was lower in irradiated PAS‐PCs.

Conclusions

PAS‐PCs irradiated with UVC from xenon flash have favorable properties to achieve hemostasis compared with nonirradiated PAS‐PCs.
Incompatibility between recipient CD47 and donor SIRPα is not a key risk factor for thrombocytopenia or anemia following rat liver xenotransplantation in mice
Authors: Li Ting , Lv Yanan , Sun Renren , Yang Yong‐Guang , Hu Zheng , Lv Guoyue
Published: October 2020

Liver xenotransplantation (LXT) is greatly impeded by severe thrombocytopenia, anemia, and coagulopathy. Hepatic phagocytic cells are thought to play an important role in LXT‐induced thrombocytopenia and anemia. In this study, we investigated whether the lack of recipient CD47‐donor SIRPα interaction, which is known to induce xenograft rejection by macrophages, exacerbates platelet and RBC depletion following LXT. We first addressed this question in the absence of anti‐donor immune responses using a syngeneic mouse liver transplantation (LT) model. Neither wild‐type (WT) nor CD47KO B6 mice developed thrombocytopenia following LT from WT B6 donors. Although a moderate decline in RBCs was detected following LT, there was no significant difference in RBC counts between WT and CD47KO recipients. Because mouse CD47 is cross‐reactive with rat SIRPα, we then compared thrombocytopenia and anemia between WT and CD47KO mice following rat LXT. Unlike syngeneic mouse LT, significant thrombocytopenia and anemia were detected following rat LXT. However, the severities of both platelet and RBC depletions were comparable between WT and CD47KO recipients. Furthermore, WT and CD47KO recipients showed a similar extent of early platelet activation. Our results indicate that CD47‐SIRPα signaling does not significantly affect the loss of platelets or RBCs following LXT, suggesting that the limited cross‐reactivity between recipient CD47 and donor SIRPα is not a significant risk factor for LXT‐induced thrombocytopenia and anemia.
Distributionally Robust XVA via Wasserstein Distance: Wrong Way Counterparty Credit and Funding Risk
Authors: Singh Derek , Zhang Shuzhong
Published: October 2020

This paper investigates calculations of robust X-Value adjustment (XVA), in particular, credit valuation adjustment (CVA) and funding valuation adjustment (FVA), for over-the-counter derivatives under distributional ambiguity using Wasserstein distance as the ambiguity measure. Wrong way counterparty credit risk and funding risk can be characterized (and indeed quantified) via the robust XVA formulations. The simpler dual formulations are derived using recent Lagrangian duality results. Next, some computational experiments are conducted to measure the additional XVA charges due to distributional ambiguity under a variety of portfolio and market configurations. Finally some suggestions for further work are discussed.
Human Rights: Universality and Domination
Authors: Tejeda González José Luis
Published: October 2020

Human rights have been recognized as one of the universal references for excellence. The question of universals has aroused many suspicions and misgivings. They are perceived as theem bodiment of hegemonic and dominant interests. The Universals acquire naturalization because they intend to recover and express the best ideals, values, customs and traditions of the world. It tends to identify them with the levels of civilization and maturation of human communities. They are seen as necessary and unavoidable and raise all kinds of resentments. In the human rights is repited this circumstance where the universal range between consensual and dominant.
Convection-Enhanced Arborizing Catheter System Improves Local/Regional Delivery of Infusates Versus a Single-Port Catheter in Ex Vivo Porcine Brain Tissue
Authors: Elenes Egleide Y. , Mehta Jason N. , Hsu Fang-Chi , Whitlow Christopher T. , Debinski Waldermar , Rossmeisl John , Tatter Stephen , Rylander Christopher G.
Published: October 2020

Standard treatment for glioblastoma is noncurative and only partially effective. Convection-enhanced delivery (CED) was developed as an alternative approach for effective loco-regional delivery of drugs via a small catheter inserted into the diseased brain. However, previous CED clinical trials revealed the need for improved catheters for controlled and satisfactory distribution of therapeutics. In this study, the arborizing catheter, consisting of six infusion ports, was compared to a reflux-preventing single-port catheter. Infusions of iohexol at a flow rate of 1 μL/min/microneedle were performed, using the arborizing catheter on one hemisphere and a single-port catheter on the contralateral hemisphere of excised pig brains. The volume dispersed (Vd) of the contrast agent was quantified for each catheter. Vd for the arborizing catheter was significantly higher than for the single-port catheter, 2235.8 ± 569.7 mm3 and 382.2 ± 243.0 mm3, respectively (n = 7). Minimal reflux was observed; however, high Vd values were achieved with the arborizing catheter. With simultaneous infusion using multiple ports of the arborizing catheter, high Vd was achieved at a low infusion rate. Thus, the arborizing catheter promises a highly desirable large volume of distribution of drugs delivered to the brain for the purpose of treating brain tumors.
Probabilistic Burst Strength Evaluation of a Filament Wound Composite Pressure Vessel
Authors: Yetgin Ali , Özaslan Emre , Acar Bülent
Published: October 2020

Nowadays composite materials are used in many different applications, such as aerospace, automotive, sport, energy due to their superior material properties in terms of high strength to weight ratio, high corrosion resistance, and great damage tolerance. One important component produced from these composite materials is pressure vessels that are generally exposed to internal pressure loading. Mechanical performance of the pressure vessel directly depends on various parameters such as material properties or winding angle etc. However, it is well known that the material properties of composites are generally dispersed. The main concern of this study is to investigate the mechanical performance of a filament wound pressure vessel in terms of first ply failure (FPF) and burst pressure under internal pressure loading taking into account uncertainty of material properties and winding angles for different layers. The distributions for each material property were found by material characterization tests and goodness-of-fit test. The winding angle was selected as a random variable. Different statistical distribution types were compared to show the effect of distribution type. Monte Carlo Simulation (MC) was performed to predict the distribution function of the mechanical response. Finite element analysis was performed to obtain stress distribution of the pressure vessel. Both stochastic FPF and burst pressure predictions were verified by test results. Also, the finite element analysis was verified by strain gauge measurements that were located on the different regions of pressure vessel. The study was performed for two different ambient temperature to show the effect of different temperatures on the material properties for composite materials. Effects of each selected parameters on the FPF and burst pressure were discussed. Probabilistic analysis showed the importance of considering the uncertainty of material properties and the winding angle to predict the mechanical performance of composite pressure vessels.
Visualization of Trapped Hydrogen Along Grain Boundaries and its Roles on Hydrogen-Induced Intergranular Fracture in Slow Strain Rate Tensile Testing of Pure Nickel
Authors: Wada Kentaro , Yamabe Junichiro , Matsunaga Hisao
Published: October 2020

It has been reported that hydrogen accumulation along grain boundaries (GBs) is an important process in the hydrogen embrittlement (HE) in pure Ni. However, there are no quantitative studies that elucidate the behavior of hydrogen accumulation and its effect on HE. Consequently, the segregating behavior of hydrogen along GBs and its role in intergranular (IG) fracture in pure Ni were examined in the present research, via a combination of thermal desorption analysis, secondary iron mass spectrometry, Auger electron spectroscopy and slow strain rate tensile testing. It was successfully demonstrated that the hydrogen trapped at GBs and the sulfur segregated along GBs contributed to the hydrogen-trapping. In addition, the contribution of trapped hydrogen on the hydrogen-induced ductility loss was quantitatively investigated. The results revealed a decreased reduction in area (RA) with a concomitant increase in trap-site occupancy, implying that the trapped hydrogen controlled the hydrogen-induced IG fracture and ductility loss in pure Ni.
Research on the Seismic Analysis and Optimization of High Flux Reactor Nuclear Power Piping System Based on Multi-Point Response Spectrum Method
Authors: Huang Xuan , Shen Pingchuan , Liu Shuai , Liu Jian , Jiang Xiaozhou , Yu Xiaofei , Xie Hai , Shi Kaikai , Ji Yuanyuan
Published: October 2020

High flux reactor is an important engineering test reactor, which can be used in irradiation research of materials, chemistry, isotopes, medicine and other fields. In the high flux reactor coolant system, there are a large number of nuclear pipes and the layout is complex. The optimization of seismic analysis method for reactor coolant system is an important part in the design process to ensure the nuclear pipes meet the design specifications. The traditional single point response spectrum method needs to envelope the response spectrum of different floors as the analysis input. This method is difficult to give the reasonable seismic load to the numerous nuclear pipes and it will increase the design cost and the difficulty of safety analysis about nuclear pipe. In this paper, an optimized seismic analysis method of reactor coolant system is proposed. By using the multi-point response spectrum method, the optimization of different excitation loading modes for different constrained support points is realized. The analysis results show that the multi-point response spectrum method can solve the problem that different support points are located at different elevation floors in the reactor coolant system, which makes the calculation results more accurate and reasonable. Compared with the traditional method, it can make the design more efficient and practical.
Deployment of Laser Peening to Prevent CISCC of Nuclear Fuel Dry Storage Canisters
Authors: Hackel Lloyd , Rankin Jon , Walter Matt , Dane C. Brent , Neuman William , Oneid Pierre , Thomas Gareth , Bidrawn Fred
Published: October 2020

By generating very deep levels of compressive stress, laser peening can eliminate stress corrosion cracking of materials of use in the nuclear industry; tested materials include Alloys N06600 (Inconel 600), N06690 (Inconel 690), N06022 (Alloy C22) and stainless steels K44220 (300M), S30400 (304) and S31600 (316L). In this work we take a further step in direct application to the welds of multi-purpose canisters (MPCs) employed for dry storage of spent fuel at nuclear plants. This storage is a temporary approach awaiting interim or permanent storage.. For storage in coastal, lakeside and even humid environments, air-entrained chlorides can make the canister welds susceptible to pitting and chloride induced stress corrosion cracking (CISCC). Using ASTM G36 (2013) accelerated corrosive testing we evaluated CISCC lifetimes of welded 316L stainless steel canister plates configured to MPC geometry showing in excess of 19 times lifetime increase of laser peened panel sections vs. those left as-welded. Specifically cracks never developed within and were arrested when propagating into the laser peened area. We measured residual stress in test plates and related it to calculations of stress intensity and depth expected in the full canister geometry. We discuss the relevance of stress depth to pitting depth and crack growth rates. Our two-dimensional stress mapping shows that high energy laser peening provides deep (> 5 mm) plastic compression in the canister material and geometry. In parallel, as we gained customer and NRC approvals, we developed and deployed the hardware and control technology that enabled a transportable system to peen canisters welds during the fabrication process. The canisters are now loaded or in process of being loaded at the San Onofre Nuclear Power Plant.
Application of Fracture Control to Mitigate Failure Consequence Under BDBE
Authors: Kasahara Naoto , Wakai Takashi , Nakamura Izumi , Sato Takuya , Ichimiya Masakazu
Published: October 2020

As a lesson learned from the Fukushima nuclear power plant accident, the industry recognized the imporatance of mitigating accident consequences after Beyond Design Basis Events (BDBE). We propose the concept of applying fracture control to mitigate failure consequences of nuclear components under BDBE.

Requirements are different between Design Basis Events (DBE) and BDBE. In the case of DBE, it requires preventing occurrence of failures, and thus, its structural approach is strengthening. On the other hand, BDBE requires mitigating failure consequences. The simple strengthening approach with DBE is inappropriate for this BDBE requirement.

As the structural strengthening approach for mitigating failure consequences, we propose applying the concept of fracture control. The fundamental idea is to control the sequence of failure locations and modes. Preceding failures release loadings and prevent further catastrophic consequent failures. At the end, locations and modes of failure are limited.

Absolute strength evaluation for each failure mode is not easy especially for BDBE. Fracture control, however, requires only relative strength evaluation among different locations and failure modes.

Our paper discusses two sample applications of our proposed method. One is a fast reactor vessel under severe accident conditions. Our method controls the upper part of a vessel above the liquid coolant surface weaker than the lower part. This strength control maintains enough coolant even after a high pressure and high temperature condition causes failure of the reactor vessel because structural failure in the upper part releases internal pressure to protect the lower part.

The other example is the piping under a large earthquake. Our proposal controls strength of supports weaker than the piping itself. When the supports fail first, natural frequencies of piping systems drop. When the natural frequencies of dominant modes are lower than the peak frequency of seismic loads, seismic loads hardly transfer to the piping and catastrophic failures such as collapse or break are avoided.
Investigation on Typical Failure Mode of High-Pressure Hydrogen Cylinders for Vehicles
Authors: Yuan Yiwen , Wang Jielu , Ding Ju
Published: October 2020

Compressed hydrogen gas cylinders with an aluminum liner and carbon fiber wound are currently used as main storage containers in hydrogen fuel cell vehicles region, such cylinders filled with hydrogen gas have the advantages of light weight, high pressure resistance etc. Owing to the fact that cylinders are generally pressurized to 35MPa-92MPa, they may have a vital impact on life and property if failure of the cylinder occurs. For risk prediction, a series of comparative experiments have been carried out and some tests results have been analyzed, where the typical failure mode of such hydrogen cylinders are summarized as irreversible failure, recoverable failure and preventable failure. Irreversible failure refers to the failure mode such as leakage, rupture and penetration, etc, which could cause the cylinder not to restore its original function. Recoverable failure includes thread damage, security attachment startup and so on. The original function of the cylinder could be repaired by repairing the thread and replacing the safety accessories. Preventable failure would be found under the condition such as load at extreme ambient temperature for a long time, filament wound layer cracking caused by surface damage, chemical corrosion and serious impact etc, which could decrease the cylinder strength. In case of existing the preventable failure, cylinders should be monitored in use and the service life would be reduced.
Mechanical and Thermal Assessment by BAM of a New Package Design for the Transport of SNF From a German Research Reactor
Authors: Komann Steffen , Ballheimer Viktor , Quercetti Thomas , Scheidemann Robert , Wille Frank
Published: October 2020

For disposal of the research reactor of the Technical University Munich FRM II a new transport and storage cask design was under approval assessment by the German authorities on the basis of International Atomic Energy Agency (IAEA) requirements. The cask body is made of ductile cast iron and closed by two bolted lid systems with metal seals. The material of the lids is stainless steel. On each end of the cask the wood-filled impact limiters are installed to reduce impact loads to the cask under drop test conditions. In the cavity of the cask a basket for five spent fuel elements is arranged.

This design has been assessed by the Bundesanstalt für Materialforschung und -prüfung (BAM) in view to the mechanical and thermal safety analyses, the activity release approaches, and subjects of quality assurance and surveillance for manufacturing and operation of the package.

For the mechanical safety analyses of the package a combination of experimental testing and analytical/numerical calculations were applied. In total, four drop tests were carried out at the BAM large drop test facility. Two tests were carried out as a full IAEA drop test sequence consisting of a 9m drop test onto an unyielding target and a 1m puncture bar drop test. The other two drop tests were performed as single 9m drop tests and completed by additional analyses for considering the effects of an IAEA drop test sequence.

The main objectives of the drop tests were the investigation of the integrity of the package and its safety against release of radioactive material as well as the test of the fastening system of the impact limiters. Furthermore, the acceleration and strain signals measured during the tests were used for the verification of finite-element (FE) models applied in the safety analysis of the package design.

The FE models include the cask body, the lid system, the inventory and the impact limiters with the fastening system. In this context special attention was paid to the modeling of the encapsulated wood-filled impact limiters.

Additional calculations by using the verified numerical model were done to investigate e.g. the brittle fracture of the cask body made of ductile cask iron within the package design approval procedure.

The thermal safety assessment was based on analytical energy balance calculations and FE analyses. As an additional point of evaluation in frame of approval procedure, the effect of possible impact limiter burning under accident conditions of transport was considered by the applicant and assessed by BAM.

This paper describes the package design assessment from the point of view of the competent authority BAM including the applied assessment strategy, the conducted drop tests and the additional calculations by using numerical and analytical methods.
Evaluation of Pressure-Temperature Limit Curve Considering Revised Stress Intensity Factor Method
Authors: Lee Yunjoo , Yoon Hyosub , Kim Kyuwan , Kim Jongmin , Kim Hyunmin
Published: October 2020

Pressure-Temperature limit methodology is based on the rules of Appendix G in Section XI of the ASME Code in accordance with the requirements of 10 CFR 50, Appendix G, and the Appendix G in Section XI method refers to Welding Research Council (WRC) Bulletin 175 (WRC175). Flaw size is an important factor to protect the reactor pressure vessel from brittle failure but is not explicitly documented in WRC175. However, according to the recent change of Appendix G, the ¼ thickness (¼T) flaw size is postulated in the surface of the nozzle inner corner for the evaluation of Pressure-Temperature limit.

In this paper, stress intensity factor is computed by using 3D finite element analysis (FEA) considering ¼T corner cracks of inlet nozzle and outlet nozzle in reactor pressure vessel. The result is compared with the stress intensity factor using influence function in the ASME Code. The results of stress intensity factor in accordance with the ASME Code are more conservative than those of the 3-D FEA with a crack. The allowable pressure and operation region in Pressure-Temperature limit curve are affected by the calculation methods of stress intensity factor.
Ground Motion Model for Seismic Vulnerability Assessment of Prototype Industrial Plants
Authors: Nardin Chiara , Lanese Igor , di Filippo Rocco , Endrizzi Roberto , Bursi Oreste S. , Paolacci Fabrizio
Published: October 2020

Relationships between seismic action, system response and relevant damage levels in industrial plants require a solid background both in experimental data, due to the high level of non-linearity and seismic input. Besides, risk and fragility analyses depend on the adoption of a huge number of seismic records usually not available in a site-specific analysis. In order to manage these issues and to gain knowledge on the definition of damage levels, limit states and performance for major-hazard industrial plant components, we present a possible approach for an experimental campaign based on a real prototype industrial steel structure. The investigation of the seismic behaviour of the reference structure will be carried out through shaking table tests. In particular, tests are focused on structural or process-related interactions that can lead to serious secondary damages as leakage in piping systems or connections with tanks and cabinets. The aforementioned test program has been possible thanks to the adoption of: i) a number of artificial spectrum-compatible accelerograms; ii) a ground motion model (GMM) able to generate a suite of synthetic time-histories records for specified site characteristic and earthquake scenarios. More precisely, GMM model parameters can be identified by matching the statistics of a target-recorded accelerogram to the ones of the model in terms of faulting mechanism, earthquake magnitude, source-to-site distance and site shear-wave velocity. As a result, the stochastic model, based both on these matched parameters and on filtered white-noise process, can generate the ensemble of synthetic ground motions capable of capturing the main features of real earthquake ground motions, including intensity, duration, spectral content and peak values. Moreover, the synthetic records are selected to target specific damages and limit states in industrial components. Finally, by means of the combination of artificial and synthetic accelerograms, a seismic vulnerability assessment of both the whole structure and relevant industrial components can be carried out.
Experimental Study on the Characteristics of Bolted Pipe Flange Connection Under Bending Moment and Internal Pressure
Authors: Zheng Xing , Sawa Toshiyuki , Feng Mei , Ding Honggui
Published: October 2020

After a bolted gasketed pipe flange connection is assembled, the pipe flange connection is usually subjected to some additional loads such as bending moment, own weight, wind load and so on. These additional loads will lead to changing the axial bolt force distribution of the pipe flange connection and the distribution will become more and more scattered. As a result, the minimum residual axial bolt force will be much smaller and the minimum contact gasket stress will decrease, so a leakage is easy to occur in the connection. In special cases such as earthquakes, the bolted pipe flange connection is usually subjected to a high bending moment. Then sometimes leakage accidents occur. In order to promote the safety of the connections and to avoid them being broken under the earthquakes, in the present paper, the equivalent pressure and the assembly efficiency in the pipe flange connection of class 150 4″ are measured experimentally. The leak rates of the connection using spiral-wound gasket when a bending moment was applied or not applied were measured to elicit the equivalent pressure. Moreover, some tightening procedures such as JIS B 2251, ASME PCC-1 Legacy and GB/T 38343 were applied to tighten the pipe flange connection. The axial bolt force distribution, the assembly efficiency based on the target axial bolt force and the assembly efficiency based on tightness parameter of the connection when bending moment was applied or not applied were measured, and the results are compared. As a result, the equivalent pressure under a given bending moment is obtained, and a difference of the equivalent pressure between our results and Kellogg’s results is demonstrated. In addition, the new assembly efficiency based on the tightness parameter is also measured under a given bending moment as well as internal pressure. Using the equivalent pressure and the assembly efficiency obtained in the present paper, a new design will be possible for pipe flange connections under bending moment.
Multiaxial Ratcheting Deformation of 316LN Stainless Steel at Elevated Temperatures
Authors: Sun Xingyue , Xing Ruisi , Chen Xu
Published: October 2020

316LN stainless steel is the main material used in the primary pipelines of the pressurized water reactor due to its excellent characteristics. In the consideration of its serious environment, the cyclic deformation of material at high temperatures is concerned. A series of multiaxial ratcheting experiments were conducted at room, 350°C and 550°C. These experiments contained circular, rhombus and uniaxial loading paths with different mean stresses and stress amplitudes. At elevated temperature conditions, it got quick shakedown in multiaxial cases which is similar in uniaxial ones indicating that dynamic strain aging (DSA) exists. Uniaxial strain was the maximum in all the test temperature. Mean stress is seemed to be always the main influence factor. The difference of ratcheting strain under rhombus path and circular path decreased from room temperature to elevated temperature, which is inferred that DSA effect may weakened the nonproportionality at elevated temperature. The ratcheting strain evolution was simulated by Chen-Jiao-Kim model with the multiaxial parameter associated with temperature.
A Hybrid PSO-BPNN Model Approach for Crude Oil Pipeline Electrical Energy Consumption Forecasting
Authors: Xu Lei , Hou Lei , Li Yu , Zhu Zhenyu , Liu Jiaquan , Lei Ting
Published: October 2020

The electrical energy consumption forecasting for crude oil pipeline is critical in many aspects, such as energy consumption target setting, batch scheduling, unit commitment, etc. For actual crude oil pipelines, the nonlinearity of the sample is strong. The electrical energy consumption of crude pipeline is affected by many parameters, including oil physical property parameter, pipe parameter, station parameter, environmental parameter and operating parameter. At the same time, the whole process has the characteristics of intermittency and complex fluctuations. The above three main reasons make the energy consumption forecasting of crude oil pipeline complicated. In the past few years, several intelligence-based models have been introduced to accurately forecast energy consumption. Among them, back-propagation neural network (BPNN) seems to be more effective and can handle the nonlinear energy behavior and achieve accurate forecast results. However, due to its over-fitting problem, the accuracy of energy consumption forecasting will be reduced. To overcome this problem, the paper proposes a hybrid method for short-term energy consumption forecasting, namely PSO-BPNN. Back propagation neural network is integrated with particle swarm optimization to find optimal network weight. In this research, an effective technique called principal component analysis is applied to eliminate redundant noise and extract the primary characteristics of transportation data. The stratified sampling method is used to divide the training set and the test set to avoid large deviations caused by the randomness of sampling. Taking a crude oil pipeline in northeast china as a case study, SCADA system data are collected daily from December 31, 2016 to June 18, 2019. Comparing the evaluation indicators of PSO-BPNN with that of five state-of-the-art forecasting methods of GA-BPNN, SA-BPNN, DE-BPNN, FOA-BPNN, BPNN, the effectiveness of PSO-BPNN algorithm is evaluated. Compared with other five forecasting methods, the forecast results of PSO-BPNN are in best agreement with the actual data. The results indicate that the proposed PSO-BPNN model outperforms all five models used for comparison, which demonstrates its superior ability to generate forecasts in terms of forecasting accuracy.
Study on Hydrogen Resistance of X42 Pipeline Steel Under Electrochemical Hydrogen Charging Condition
Authors: Bai Guangqian , Wang Qiuyan , Song Yan , Deng Haiquan , Li Donglin , Li Yun
Published: October 2020

With the development of renewable energy, hydrogen energy is paid more and more attention. Hydrogen is an excellent energy carrier, but it is difficult to store and transport because of its special properties. Hydrogen blended with nature gas is considered to be one of best transition solutions to solve the problem of large-scale hydrogen transportation. But hydrogen embrittlement occurs when the pipeline steel used to transport natural gas is exposed to hydrogen environment. Referencing to ASME B31.12, X42 pipeline steel is selected as the research object in this paper. And the mechanical properties of X42 were tested by electrochemical hydrogen charging, slow strain rate tensile (SSRT) test and fatigue crack growth (FCG) test combined with thermal desorption spectroscopy (TDS) and SEM. Hydrogen adsorption properties of X42 pipeline steel at room temperature was measured by TDS. SSRT test showed that the strength of X42 strengthened slightly in electrochemical hydrogen charging environment, but the plasticity decreased significantly, and the embrittlement degree of materials increased with the elevated current density. FCG test showed that the presence of hydrogen will accelerate the crack growth rate and reduce the fatigue life of materials. SEM images of tensile and fatigue specimens showed that hydrogen transforms the fracture mode from ductile fracture to cleavage fracture.
Research on the Inspection Parameters of Ultrasonic Phased Array for the Periodic Inspection of High-Pressure Hydrogen Vessel
Authors: Miao Cunjian , Guo Weican , Ling Zhangwei , Tao Yangji , Yu Ting , Tang Ping
Published: October 2020

Steel layered high-pressure hydrogen vessel is one of different kinds of high-pressure vessel, which is invented in China and is widely equipped in hydrogen refueling stations for its good safety and storage functions. Many of these vessels are put into application these years, and it is nearly the time for these vessels to go through periodic inspection. However, there is no such a method for the periodic inspection especially on the butt weld connecting the double-layer head and the interface forging. To conquer the difficulties about the periodic inspection, a set of periodic inspection methods was first proposed in a lasted released Chinese group standard, in which the inner ultrasonic phased array is considered to be the most complicated detecting approach. To establish effective inspection parameters, simulations and experiments were conducted on the factors, including coupling, elements and aperture, focal law, scanning approaches and ultrasound field. Standard test block and contrast test block were designed and machined and tested, then a series of feasible parameters were determined. Thus, specific probe, wedge and instrument were manufactured, and the inspection on the actual vessel product was carried out. The results showed that the proposed ultrasonic method and its inspection parameters could meet the periodic inspection well. Finally, the periodic inspection methods were established and issued as a standard.
Effects of Stud Galling on Bolted Flange Joint Assembly Performance
Authors: Dupre Ross
Published: October 2020

This study will focus on the galling of studs and what impact that has on the overall performance of a Bolted Flange Joint Assembly. Galling or “cold welding” occurs more so with softer metals. While tightening the nut on to the stud the contact metal will “pull” away from itself and the two surfaces will essentially become one. Once this happens the nut cannot be tightened or loosened and often cutting the stud is the only form of removal.

We’ll be studying how this affects the performance (tightness) of a bolted flange joint assembly. Does the assembly loosen over time or does it remain at the proper tightness? Data will be captured using load cells to accurately represent the amount of force being generated by test studs. There will be a standard test ran with no galling. All other tests with galled studs will be measured and compared against the standard test. One test with only one stud galled, the next with two studs galled, the next with three studs galled, and so on. It may be expected to see some load loss on the load cells with the galled studs. The integrity of the studs, once galled, becomes less than ideal.
Failure Assessment of Spring-Operated Pressure Relief Valve Proof Test Data for Extending Time-in-Service
Authors: Bukowski Julia V. , Gross Robert E. , Harris Stephen P. , Goble William M.
Published: October 2020

The proof test results of 1669 Spring-Operated Pressure Relief Valves (SOPRV), which were previously installed in active processes, were analyzed with respect to proof test ratio (R), time-in-service (TIS), set pressure (SP), working fluid (WF), material composition of the SOPRV and, if an SOPRV failed-to-open (FTO), the root cause of failure in the FTO failure mode if available. Many of these SOPRV had accumulated TIS in excess of the normal maximum of five years yet proof testing indicated that most would have functioned properly. This paper examines the results of the analysis and provides guidelines under which it is appropriate to consider extending TIS for individual SOPRV.
Numerical Modelling of Compression Stress Relaxation and Compression Set of Elastomer O-Ring During Aging
Authors: Zaghdoudi Maha , Weber Mike , Kömmling Anja , Jaunich Matthias , Wolff Dietmar
Published: October 2020

Elastomer seals are used in many industrial applications due to their excellent mechanical properties at a wide range of temperatures. Their high versatility and recovery potential under several load conditions make them well suitable for the application in containers designed for transport, storage and/or disposal of radioactive materials. In containers for low and intermediate level radioactive waste, elastomer seals are used as barrier seals, and as auxiliary seals in storage and transportation casks (dual purpose casks) for heat generating radioactive waste, such as spent fuel and high-level waste. While a seal exchange at defined intervals is typical in many conventional applications, it is impossible or at least hard to perform when principles of minimization of radiation exposure have to be considered and prohibit an unnecessary cask handling. An extensive knowledge of the change of the elastomer’s properties during aging and the availability of reliable end-of-lifetime criteria to guarantee the permanent safe enclosure of the radioactive material is mandatory. As BAM is involved in most of the national cask licensing procedures and in the evaluation of cask-related long-term safety issues, great efforts have been already made and are still planned to scientifically support this task.

Compression stress relaxation and compression set were identified as key indicators of elastomer long-term performance and quantitatively investigated in comprehensive test programs. Among other representative types of elastomers, specimens made from ethylene propylene diene rubber (EPDM) were tested before, during and after aging to capture the most important of their complex mechanical properties.

In the presented study, exemplary results were used to simulate the compression stress relaxation and the compression set of elastomer O-rings during aging. Regarding the influence of temperature, the time-temperature superposition principle is applied in the relaxation analysis of elastomer O-rings. The proposed model is implemented in the commercial finite element software ABAQUS/Standard® [1] with a sequential temperature displacement coupling. Numerical results match the experimental compression stress relaxation measurements well. The prediction of compression set values after long-term aging shows a relatively good agreement with the experimental results. Nevertheless, all input parameters derived from the specimen tests, additional assumptions concerning boundary conditions and modeling strategy are discussed with regard to the identified slight discrepancies.

The possibility to extend the finite element model to represent the O-ring seal’s ability to recover after a (fast) partial release is taken into account.