bluuebunny/crossref_metadata_2025 huggingface dataset:
SEQUENTIAL PRICE SETTING: THEORY AND EVIDENCE FROM A LAB EXPERIMENT
Authors: Heggedal Tom‐Reiel , Helland Leif , Moen Espen R.
Published: November 2023

In the Varian (1980; American Economic Review 70(4) (1980), 651–59) model of price competition, a change from simultaneous to sequential price setting dramatically changes equilibrium strategies, and in the unique symmetric, equilibrium prices are pushed up to the monopoly price. There also exists an asymmetric equilibrium with lower average prices. Our main contribution is to test these predictions in the laboratory. Our data strongly support the qualitative model predictions. However, a fraction of players set low prices in accordance with the asymmetric equilibrium, which is puzzling. We show that the puzzle to a large extent can be resolved by introducing competitive preferences in the model.
A comparative analysis of chronic inducible urticaria in 423 patients: Clinical and laboratory features and comorbid conditions
Authors: Ornek Ozdemir S. , Kuteyla Can P. , Degirmentepe E. N. , Cure K. , Singer R. , Kocaturk E.
Published: November 2023

Background

Chronic inducible urticaria (CIndU) is a subtype of chronic urticaria (CU) which require specific physical or non‐physical triggers to occur. They may be isolated or may coexist with chronic spontaneous urticaria (CSU). Despite their frequent appearance in dermatology clinics, there is scarce information on the distinguishing features among the most common subtypes of CIndU as well as isolated CIndU versus CSU plus CIndU.

Objectives

To compare clinical and laboratory characteristics, and comorbid conditions among the most common CIndU types and isolated CIndU versus CSU plus CIndU.

Methods

We retrospectively analysed CIndU patients and compared patients' demographic, clinical and laboratory characteristics across isolated CIndU, CSU plus CIndU, symptomatic dermographism (SD), cold urticaria (ColdU) and cholinergic urticaria (ChoU).

Results

A total of 423 patients (~70% isolated CIndU, ~30% CSU plus CIndU, ~5% mixed CIndU subtypes) were included in the study. The most frequent CIndU subtypes were SD (68.6%; 290/423), ColdU (11.4%; 48/423) and ChoU (10.9%; 46/423). Isolated CIndU patients were younger than CSU plus CIndU (33.74 ± 12.72 vs. 37.06 ± 11.84, p = 0.010). Angioedema, emergency referrals, need for systemic steroids, comorbid systemic disorders were more frequent and baseline urticaria control test scores were lower in CSU plus CIndU patients (vs. CIndU, p < 0.001, p = 0.008, p < 0.001, p = 0.031, p = 0.036, respectively). Among CIndU subtypes, ChoU patients were younger (24.9 ± 12.2 vs. 34.47 ± 12.12 vs. 31.38 ± 14.95; p < 0.001) and had male predominance (p < 0.001) while SD patients had no angioedema (p < 0.001) and had higher frequency of increased total IgE levels (p = 0.006).

Conclusions

Isolated CIndU and CSU plus CIndU seems to be different endotypes of CU where CSU plus CIndU presents a more severe and refractory course. There are distinctive features of each CIndU subtype. These suggest involvement of different pathomechanistic pathways in these subtypes that need to be clarified in future studies.
Prediction of duloxetine efficacy in addition to self‐management in painful temporomandibular disorders: A randomised, placebo‐controlled clinical trial
Authors: Ferreira Dyna Mara Araújo Oliveira , Soares Flávia Fonseca Carvalho , Raimundini Amanda Ayla , Bonjardim Leonardo Rigoldi , Costa Yuri Martins , Conti Paulo César Rodrigues
Published: November 2023

Background

Conditioned pain modulation (CPM) is a potential predictor of treatment response that has not been studied in temporomandibular disorders (TMD).

Objectives

We conducted a randomised, double‐blind, placebo‐controlled trial (RCT) of duloxetine in addition to self‐management (SM) strategies to investigate its efficacy to reduce pain intensity in painful TMD patients. Moreover, we investigated whether baseline CPM would predict the duloxetine efficacy to reduce TMD pain intensity.

Methods

Eighty participants were randomised to duloxetine 60 mg or placebo for 12 weeks. The primary outcomes were the change in the pain intensity from baseline to week‐12 and CPM‐sequential paradigm at baseline. Safety, physical and emotional functioning outcomes were also evaluated.

Results

Of 80 participants randomised, 78 were included in intention‐to‐treat analysis. Pain intensity decreased for SM‐duloxetine and SM‐placebo but did not differ between groups (p = .82). A more efficient CPM was associated with a greater pain intensity reduction regardless of the treatment group (p = .035). Physical and emotional functioning did not differ between groups, but adverse events (p = .014), sleep impairment (p = .003) and catastrophizing symptoms (p = .001) were more prevalent in SM‐duloxetine group.

Conclusion

This study failed to provide evidence of a beneficial effect of adding duloxetine to SM strategies for treatment of painful TMD. Nonetheless, this RCT has shown the feasibility of applying pain modulation assessment to predict short‐term treatment response in painful TMD patients, which confirms previous finds that CPM evaluation may serve a step forward in individualising pain treatment.
L2 Learners’ Signed Language Processing Relates, in Part, to Perspective‐Taking Skills
Authors: Quinto‐Pozos David , Renee Joyce Taylor , Sarkar Abhra , DiLeo Michael , Hou Lynn
Published: November 2023

The comprehension of signed language requires linguistic and visual–spatial processing, such as perspective‐taking for correctly interpreting the layout of a spatial scene. However, little is known about how adult second‐language (L2) learners process visual–spatial constructions in a signed language that they are studying, including which angles of viewing are most challenging to process and whether there are relationships between perspective‐taking and the comprehension of non‐spatial (i.e., non‐scene based) constructions. We examine the performance of 95 intermediate signers of American Sign Language (ASL) on linguistic and non‐linguistic perspective‐taking tests. Half the participants completed a test of narrative comprehension that included visual–spatial scenes, and half took a test of signed phonological and morphophonological discrimination. Performance on linguistic perspective‐taking correlated moderately with performance on the narrative, but not with the discrimination test. These findings support the claim that perspective‐taking skills are yoked to some—but not all—aspects of signed language learning.
Mineralogy and petrology of fine‐grained samples recovered from the asteroid (162173) Ryugu
Authors: Noguchi Takaaki , Matsumoto Toru , Miyake Akira , Igami Yohei , Haruta Mitsutaka , Saito Hikaru , Hata Satoshi , Seto Yusuke , Miyahara Masaaki , Tomioka Naotaka , Ishii Hope A. , Bradley John P. , Ohtaki Kenta K. , Dobrică Elena , Leroux Hugues , Guillou Corentin Le , Jacob Damien , de la Peña Francisco , Laforet Sylvain , Mouloud Bahae‐Eddine , Marinova Maya , Langenhorst Falko , Harries Dennis , Beck Pierre , Phan Thi H. V. , Rebois Rolando , Abreu Neyda M. , Gray Jennifer , Zega Thomas , Zanetta Pierre‐M. , Thompson Michelle S. , Stroud Rhonda , Burgess Kate , Cymes Brittany A. , Bridges John C. , Hicks Leon , Lee Martin R. , Daly Luke , Bland Phil A. , Smith William A. , McFadzean Sam , Martin Pierre‐Etienne , Bagot Paul A. J. , Fougerouse Dennis , Saxey David W. , Reddy Steven , Rickard William D. A. , Zolensky Michael E. , Frank David R. , Martinez James , Tsuchiyama Akira , Yasutake Masahiro , Matsuno Junya , Okumura Shota , Mitsukawa Itaru , Uesugi Kentaro , Uesugi Masayuki , Takeuchi Akihisa , Sun Mingqi , Enju Satomi , Takigawa Aki , Michikami Tatsuhiro , Nakamura Tomoki , Matsumoto Megumi , Nakauchi Yusuke , Abe Masanao , Nakazawa Satoru , Okada Tatsuaki , Saiki Takanao , Tanaka Satoshi , Terui Fuyuto , Yoshikawa Makoto , Miyazaki Akiko , Nakato Aiko , Nishimura Masahiro , Usui Tomohiro , Yada Toru , Yurimoto Hisayoshi , Nagashima Kazuhide , Kawasaki Noriyuki , Sakamotoa Naoya , Hoppe Peter , Okazaki Ryuji , Yabuta Hikaru , Naraoka Hiroshi , Sakamoto Kanako , Tachibana Shogo , Watanabe Sei‐ichiro , Tsuda Yuichi
Published: November 2023

Samples returned from the carbonaceous asteroid (162173) Ryugu by the Hayabusa2 mission revealed that Ryugu is composed of materials consistent with CI chondrites and some types of space weathering. We report detailed mineralogy of the fine‐grained Ryugu samples allocated to our “Sand” team and report additional space weathering features found on the grains. The dominant mineralogy is composed of a fine‐grained mixture of Mg‐rich saponite and serpentine, magnetite, pyrrhotite, pentlandite, dolomite, and Fe‐bearing magnesite. These grains have mineralogy comparable to that of CI chondrites, showing severe aqueous alteration but lacking ferrihydrite and sulfate. These results are similar to previous works on large Ryugu grains. In addition to the major minerals, we also find many minerals that are rare or have not been reported among CI chondrites. Accessory minerals identified are hydroxyapatite, Mg‐Na phosphate, olivine, low‐Ca pyroxene, Mg‐Al spinel, chromite, manganochromite, eskolaite, ilmenite, cubanite, polydymite, transjordanite, schreibersite, calcite, moissanite, and poorly crystalline phyllosilicate. We also show scanning transmission electron microscope and scanning electron microscope compositional maps and images of some space‐weathered grains and severely heated and melted grains. Although our mineralogical results are consistent with that of millimeter‐sized grains, the fine‐grained fraction is best suited to investigate impact‐induced space weathering.
Testing the trade‐balance model: resource stoichiometry does not sufficiently explain AM effects
Authors: Corrêa Ana , Ferrol Nuria , Cruz Cristina
Published: November 2023

Variations in arbuscular mycorrhizae (AM) effects on plant growth (MGR) are commonly assumed to result from cost : benefit balances, with C as the cost and, most frequently, P as the benefit. The trade‐balance model (TBM) adopts these assumptions and hypothesizes that mycorrhizal benefit depends on C : N : P stoichiometry. Although widely accepted, the TBM has not been experimentally tested.

We isolated the parameters included in the TBM and tested these assumptions using it as framework. Oryza sativa plants were supplied with different N : P ratios at low light level, establishing different C : P and C : N exchange rates, and C, N or P limitation. MGR and effects on nutrient uptake, %M, ERM, photosynthesis and shoot starch were measured.

C distribution to AM fungi played no role in MGR, and N was essential for all AM effects, including on P nutrition. C distribution to AM and MGR varied with the limiting nutrient (N or P), and evidence of extensive interplay between N and P was observed.

The TBM was not confirmed. The results agreed with the exchange of surplus resources and source–sink regulation of resource distribution among plants and AMF. Rather than depending on exchange rates, resource exchange may simply obey both symbiont needs, not requiring further regulation.
Macrophage‐derived apoptotic bodies impair the osteogenic ability of osteoblasts in periodontitis
Authors: Liu Xu , Guo Lijia , Du Juan , Luo Zhenhua , Xu Junji , Bhawal Ujjal Kumar , Li Xiaoyan , Liu Yi
Published: November 2023

Objectives

Periodontitis is induced by the imbalance between osteoblast and osteoclast activity, which leads to periodontal tissue destruction. Macrophages play a vital role in periodontitis. However, the hypoxic periodontal environment will also induce macrophage apoptosis within a short time. Apoptotic bodies (ABs) are the major products generated from apoptotic cells, but whether macrophage‐derived ABs play a regulatory role as their mother cells in periodontitis remains unknown. In the present study, we aimed to investigate the effects of ABs on osteoblasts.

Method

ABs derived from hypoxia‐induced macrophages were co‐cultured with osteoblasts and the impact of ABs on osteoblast differentiation in vitro was assessed. In vivo, periodontitis model was established and macrophages‐derived ABs were injected into the gingival sulcus. The effects of ABs on periodontal bone resorption were determined.

Results

The results showed that ABs significantly inhibit osteoblast differentiation and promoted alveolar bone resorption in periodontitis. MicroRNA (miRNAs) array analysis was performed and revealed that miR‐483‐5p is the key miRNA in ABs. Dual luciferase reporter assays were performed and confirmed that miR‐483‐5p targeted Col1A1 mRNA and attenuated its expression.

Conclusion

Macrophage‐derived ABs inhibit osteoblast differentiation via the transfer of miR‐483‐5p, which downregulates Col1A1 expression and finally suppresses osteogenic activity.
Emerging costs in a “hidden” workforce: The longitudinal psychosocial effects of caregiving during the COVID‐19 pandemic among Norwegian adults
Authors: Hansen Thomas , Hynek Kamila , McMunn Anne , Nes Ragnhild Bang , Skirbekk Vegard , Vollrath Margarethe E. , Methi Fredrik
Published: November 2023

During COVID‐19 many informal caregivers experienced increased caregiving load while access to formal and informal support systems and coping resources decreased. Little is known about the psychosocial costs of these challenges for an essential yet vulnerable and “hidden” frontline workforce. This study explores and compares changes in psychosocial well‐being (psychological well‐being, psychological ill‐being, and loneliness) before and across up to three stages of the COVID‐19 pandemic among caregivers and non‐caregivers. We also examine predictors of psychosocial well‐being among caregivers during the peak of the pandemic. We use longitudinal data collected online in the Norwegian Counties Public Health Survey (age: 18–92) in four counties and up to four data points (n = 14,881). Caregivers are those who provide care unpaid, continuous (≥ monthly across all time points) help to someone with health problems. Findings show that levels of psychosocial well‐being first remained stable but later, during the peak stages of the pandemic, dropped markedly. Caregivers (13–15% of the samples) report lower psychosocial well‐being than non‐caregivers both before and during the pandemic. Caregivers seem especially vulnerable in terms of ill‐being, and during the peak of the pandemic caregivers report higher net levels of worry (OR = 1.22, p < 0.01) and anxiety (OR = 1.23, p < 0.01) than non‐caregivers. As expected, impacts are graver for caregivers who provide more intensive care and those reporting health problems or poor access to social support. Our study findings are valuable information for interventions to support caregivers during this and future pandemics.
Cognitive and Apathetic Racism in Patterns of Gun Ownership and Gun Control Attitudes
Authors: Nielsen Amie L. , Kelley Margaret S. , Ellison Christopher G. , Johnson Oshea , Gervais Bryan T.
Published: November 2023

Our objective is to expand upon the emerging literature that examines the role of multiple forms of racism in gun ownership and gun control attitudes among non‐Latino whites. While some of these studies, using standard measures of racial resentment, speculate about the color‐coded nature of crime and whether this partially motivates gun ownership, here we specifically consider whether cognitive and apathetic types of racism along with explicit racism are associated with gun ownership and attitudes. In doing so, we advance the literature by using novel measures of racism and focus on generalized racial attitudes, not just anti‐black views. We use data from the Guns in American Life Survey, an online survey using a national sample of adult respondents, and apply regression techniques to assess whether general racial attitudes, including fear of non‐whites, are associated with gun ownership and gun control attitudes net of control variables. The multivariate results suggest that racism, including fear of other races, is not associated with gun ownership. However, cognitive and apathetic indicators of racism influence gun control attitudes for at least some whites. The implications are that racism in various forms needs to be considered in all studies involving gun‐related issues.
Elongation factor MdEF‐Tu coordinates with heat shock protein MdHsp70 to enhance apple thermotolerance
Authors: Che Runmin , Liu Yuerong , Yan Shengqi , Yang Chao , Sun Yubo , Liu Changhai , Ma Fengwang
Published: November 2023

High‐temperature stress results in protein misfolding/unfolding and subsequently promotes the accumulation of cytotoxic protein aggregates that can compromise cell survival. Heat shock proteins (HSPs) function as molecular chaperones that coordinate the refolding and degradation of aggregated proteins to mitigate the detrimental effects of high temperatures. However, the relationship between HSPs and protein aggregates in apples under high temperatures remains unclear. Here, we show that an apple (Malus domestica) chloroplast‐localized, heat‐sensitive elongation factor Tu (MdEF‐Tu), positively regulates apple thermotolerance when it is overexpressed. Transgenic apple plants exhibited higher photosynthetic capacity and better integrity of chloroplasts during heat stress. Under high temperatures, MdEF‐Tu formed insoluble aggregates accompanied by ubiquitination modifications. Furthermore, we identified a chaperone heat shock protein (MdHsp70), as an interacting protein of MdEF‐Tu. Moreover, we observed obviously elevated MdHsp70 levels in 35S: MdEF‐Tu apple plants that prevented the accumulation of ubiquitinated MdEF‐Tu aggregates, which positively contributes to the thermotolerance of the transgenic plants. Overall, our results provide new insights into the molecular chaperone function of MdHsp70, which mediates the homeostasis of thermosensitive proteins under high temperatures.
Functional assays reflective of cancer hallmarks in BT‐549 cells are not impacted by media supplemented with exercise‐trained plasma
Authors: Darragh Ian A. J. , Martinez‐Pacheco Sarai , O'Driscoll Lorraine , Egan Brendan
Published: November 2023

Media supplemented with sera from acutely exercised men has been shown to have ‘anti‐cancer’ effects on prostate and breast cancer cell lines. This study investigated whether media supplemented with plasma samples taken at rest (≥30 h since the most recent exercise session) from men who were endurance‐trained (END), strength‐trained (STR) or recreationally active controls (CON) impacted the results of four assays that mimic hallmarks of cancer (proliferation, migration, extracellular matrix invasion and anoikis resistance) in the BT‐549 breast cancer cell line. Compared to control conditions of either serum‐free media or fetal bovine serum as appropriate, BT‐549 cells cultured with plasma‐supplemented media regardless of group resulted in greater cell proliferation (∼20–50%) and cell migration (∼15–20%), and lower extracellular matrix invasion (∼10–20%) and anoikis resistance (∼15–20%). Supplementing media with plasma from END or STR did not impact any outcomes of these assays compared to plasma from CON. Media supplemented with human plasma can impact functional assays reflective of cancer hallmarks in BT‐549 cells, but effects of exercise on proliferation, migration, extracellular matrix invasion and anoikis resistance were not evident in resting blood samples of individuals with a prior history of exercise training.
Regularization Parameter Identification for Nonlinear Inverse Modeling of Atmospheric Emissions
Authors: Dong Xinwen , Zhuang Shuhan , Xu Yuhan , Fang Sheng
Published: November 2023

Regularized inverse modeling techniques formulate the rate estimation problem of airborne pollutant emission with the residual and regularization terms. In iterative minimization, the first term purposes to reduce the discrepancies between the atmospheric dispersion simulations and the environmental observations, and the second term ensures a stable solution and shapes the temporal features of emissions. The regularization parameter specifies the proportion of two terms, indirectly affecting the behavior of the solution. However, an identification approach may not suit all forms of regularized inverse models, for instance, the nonlinear Tikhonov method and the total variation (TV) method. In this paper, we have investigated three identification approaches that couple with nonlinear inverse models, a total of six combinations, to estimate the Cesium-137 emission rate following the Fukushima accident. Among them, the L-curve approach always provides the largest parameter value. The regularization works even with a small parameter, especially the TV method. The GCV approach brings the best Tikhonov estimation of the total amount, but the cost-α simultaneous minimization results in nearly the best metrics of concentration simulations in all combinations. Using the same identification approach, the TV estimate provides both the peak and constant emissions that is closer to the well-regarded subjective estimate.
Analysis on the 137Cs Transport and Deposition Simulation During the Fukushima Accident Based on WRF-Chem V4.2
Authors: Zhuang Shuhan , Dong Xinwen , Fang Sheng
Published: November 2023

Following the Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011, large amounts of 137Cs were released and transported through the atmosphere, leading to great radioactivity deposition in Japan. WRF-Chem model is often used to simulate the long-range transport of pollutants and has been widely applied in radionuclides release after the nuclear accident, i.e., the Fukushima accident. With microphysics, boundary layer schemes and many other schemes proposed and integrated into the source code, the WRF-Chem model has been upgrading all the time. However, few studies have adopted the latest version of WRF-Chem for simulation, and most work has been done based on WRF-Chem of version before 4.0. In order to get access to more proposed schemes available only in the new version of WRF-Chem and evaluate the performance of WRF-Chem in radionuclide transport modeling, the simulation of 137Cs transport in the Fukushima accident based on WRF-Chem 4.2 has been conducted. In this paper, the in-cloud (Roselle) and below-cloud (Baklanov) schemes, which have been proven to perform well in WRF-Chem 3.5, were integrated into WRF-Chem 4.2. The results of WRF-Chem 4.2 have been evaluated comprehensively with respect to cumulative deposition and atmospheric concentration. As the results indicated, WRF-Chem 4.2 reproduces the high deposition area in Fukushima and Nakadori well and reaches the good performance criteria with a RANK over 2. However, it presents an overestimated cumulative deposition amount and overestimated the further Gunma and Tochigi. As for concentration simulation, WRF-Chem 4.2 shows a RANK2 slightly over 1 and the plume events are not captured well. Further improvement should be done on the parameterizations of WRF-Chem 4.2.
Creation of a Digital Model to Support Decontamination, Dismantling and Demolition of a Nuclear Facility
Authors: Del Gatto Marco , Rinaldi Martina , Giacalone Giorgio , Di Lascio Ivan , Cretoni Mattia , Mauro Egidio , Del Bene Cristiana
Published: November 2023

Nucleco S.p.A. has recently invested some of its financial and human resources in a new activity which concerns the virtualisation of nuclear facilities. This process involves three main steps: the digitalisation of plant legacy data, the point cloud acquisition and finally the 3D parametric model creation. The digitalisation and study of plant legacy data allow a preliminary analysis of the area of interest. Then, by using different kinds of instrument and software, multiple point clouds (of a single scan) of the environment are acquired and merged into the “Project Point Cloud”. This final cloud not only is fully explorable and searchable, but also can be equipped with conventional and radiological tags (such as component data sheets, instrument manuals, area dose rates, etc.). The last step, the 3D parametric model creation, is carried out using specific kinds of software, comparing the geometrical data of the point cloud to the geometrical information of the digitalised legacy data. The model then allows storage of the plant data into a single digital archive (point cloud included), supports plant management, and optimises planning of the decommissioning activities. In this paper, the process of 3D model generation is presented and contextualised with actual reconstruction examples.
Overview of LILW Disposal Facility Project in Slovenia
Authors: Mechora Špela , Viršek Sandi
Published: November 2023

The project of low and intermediate level waste (LILW) disposal facility in Slovenia started with the siting process in a year 2004. After field investigation and based on experts’ criteria the site Vrbina in municipality Krško was selected. The disposal concept in a near-surface silo was approved by the government decree within the state spatial plan in a year 2009. The final design of the disposal facility was prepared in 2015. Next step was to prepare the Environmental impact assessment report and a Preliminary safety report. In a year 2019 the Preliminary consent from Slovenian nuclear safety administration was issued. In the process of an environmental assessment public hearings were held in Slovenia as well as in interested neighboring countries. The project got environmental consent in the year 2021. This was a major milestone in getting the construction license for the disposal facility.

Several iterations of safety assessment were done; the last one in years 2018–2019, which was used as an input for Safety report for the construction. Early in year 2022 the Slovenian nuclear safety administration issued a consent for a construction which was the second major milestone towards construction license. The project of LILW disposal facility in Slovenia got the construction license for a nuclear facility in a year 2022. The construction license for the infrastructure was issued early in the year 2023.
Comparison of Intelligent Optimization Algorithms in Neural Network Model for Nuclear Accident Source Term Evaluation
Authors: Song Jiayue , Yang Li , Li Huanting , Li Xinpeng
Published: November 2023

After a severe nuclear accident, the source term cannot be obtained by the forward method due to the power outage of the whole plant. But the source term needs to be estimated quickly and accurately to protect the public and the environment. The source term inversion method based on the backpropagation neural network can effectively estimate the source term, but it is prone to fall into local minimum. To solve this problem, many intelligent optimization algorithms have been proposed to optimize the weights and thresholds of neural networks. In order to compare the effectiveness of different intelligent optimization algorithms, this paper builds neural network models based on Whale Optimization Algorithm (WOA), Genetic Algorithm (GA), Particle Swarm Optimization Algorithm (PSO), Simulated Annealing-Genetic Algorithm (SAGA) and Mindset Evolution Algorithm (MEA). And the Wind diagnose model and air dispersion model (CALMET-LAPMOD) was used to generates a large amount of data for neural network training near Sanmen Nuclear Power Plant. In addition, this study uses kernel principal component analysis (KPCA) to reduce data dimensionality and training time. The results show that the model using the WOA has the best source term estimate ability, and the relative error of test data is only 4.31%. Therefore, the WOA-KPCA neural network is recommended in similar nuclear accident emergency or consequence evaluation scenarios by this study.
Experimental Investigation of Aged Concrete From Ukraine Nuclear Plant
Authors: Cancemi Salvatore Angelo , Lo Frano Rosa , Dolin Viktor , Lezzerini Marco , Pagnotta Stefano
Published: November 2023

The various forms of cement and concrete are the most common materials used in the nuclear field because they are strong, durable, inexpensive, and shield radiation well. However, the porous nature of the prepared cement and the ever-present water in them may often result in the incorporation and retention of some radioactive species, especially tritiated water, which could be subsequently released into the environment. This study is aimed to investigate the effects and threats posed to the nuclear facility and/or repository where radioactive wastes (RWs, including SNF) are and must be stored.

Concrete represents the primary barrier to migration in many proposed low-level waste storage facilities. While it may retard some dissolved ions to varying extents, it is not clear to what extent tritium movement through concrete would take place over longer periods. The breaking of concrete atomic bonds is so responsible for the degradation of the concrete (i.e., modification of its structural and mechanical properties).

The experimental characterization to determine the physic-chemical properties of aged concrete (samples are from the vault of Kyiv RAW facility in Ukraine exposed during almost 60 years in semi-natural conditions) was performed by means of an Electronic Scanning Microscope, X-Ray diffraction, and other novel chemical and physical methods that are available at UNIPI.

The results obtained show a different water concentration confirming the filtration phenomenon the concrete took place also affecting its ultimate strength.
Estimation of Cesium Penetration Into Concrete Structures After an Experimental Decontamination Activity
Authors: Tonti Andrea , Rizzo Francesco , Giannetti Fabio
Published: November 2023

As part of its institutional competences, INAIL (National Institute for Insurance against Accidents at Work) promotes and carries out activities for preventing the risks to which workers may be subjected to in different work scenarios.

One of these research activities pursued and concluded was about the decontamination and securing of 38 concrete wells, which in former time contained radioactive sources, namely 137Cs.

In a first phase, it was used a decontaminant liquid to remove part of radionuclides from concrete walls, and after, in a second phase, these liquids were treated with an evaporative process to minimize radioactive waste.

Measurements of superficial activity before and after the decontamination and the quantity of radionuclides in the removed liquid revealed that some radioactivity was taken off, but not totally.

The question after that the activity was done is how much in depth contamination has arrived.

For having an answer about the penetration, there should be extracted some specimens from concrete, but for various problems, due to risks associated to the site, this wasn’t possible.

So, a solution is to use some mathematical models and equations combined each other for having an estimation of the penetration of cesium into the walls of these holes.
Applying Early-Stage Energy Justice Metrics to Nuclear Engineering
Authors: Kendall Bryan A. , Arkhurst Bettina K.
Published: November 2023

Environmental and energy justice implications of nuclear technologies, particularly at early stages of research and development, are often considered an afterthought to be dealt with later in technology deployment and use. Avoidable consequences on vulnerable communities are thus missed, leaving them to reap disproportionate burdens of these nuclear technologies. Currently, nuclear engineers and researchers lack the education and tools needed to readily consider justice in their work. The Justice Underpinning Science and Technology Research (JUST-R) metrics framework developed at the National Renewable Energy Laboratory seeks to provide researchers with a framework to consider the distributional, recognition, procedural, and cosmopolitan justice implications of their work at early stages. Yet JUST-R does not consider restorative justice, a particularly relevant justice concept for nuclear engineering, which is informed by a technology’s historical context. This work dilates the JUST-R framework to include restorative justice metrics and applies it to a pilot case study in the University of New Mexico’s (UNM) nuclear engineering program. Given the rich history of the nuclear industry in the state of New Mexico, UNM is embedded in a diverse ecosystem of nuclear-focused national laboratories, mining companies, and defense institutions. The results of this study fill existing gaps in the JUST-R framework to make it more relevant to nuclear engineering. This study further provides insight into how the process of conducting scientific research can be transformed to prioritize the minimization of harm to frontline communities and highlights the potential benefits of embedding justice in nuclear engineering curricula.
Application of the Reflowable Magnetic Jig on Thin MCM Package for Warpage Control
Authors: Park Jong-Chan , Kim Young-Min , Lee Gil-Ho , Kim Hyeong-Kwan , Lee Tae-Keun
Published: November 2023

For portable and wearable devices, having good functionality and being lightweight are a must. To improve the functionality of the device, System-in-Package (SiP), Package-on-Package (PoP), Multi-Chip-Module (MCM), or Chip-on-Wafer-on-Substrate (CoWoS) are good packaging options. These devices and their printed circuit boards (PCBs) are designed to be thin and lighter for many applications and the severe warpage is one of the serious reliability concerns. The warpage has caused reliability issues such as soldering defects, bridging, stretching, head-in pillow, and non-wet opens. The warpage is caused by the CTE mismatches of the materials under temperature excursion during the manufacturing process of the package. Therefore, a good selection of materials or operating temperatures may help mitigate the deformation. Unfortunately, this type of warpage control is very difficult and complex for SiP, PoP, or McM packages because there are many components to be soldered together using different processing temperatures.

To address the serious issue of warpage, we have developed a reflowable jig holder which can hold an array of MCM packages. Our jig holder is different from traditional ones that use end-clamping or only have clamp force in the inactive regions outside the functional package areas. Our reflowable jig holder implements magnets to apply forces on both inactive and active regions. With a Sm-Co magnet inside the reflowable jig at the bottom and a ferromagnetic cover on the top, we were able to better control the warpage. Experimentally, we have designed, fabricated, and tested four different magnetic jigs. Two different magnets having different diameters and weights, and two jigs with different thicknesses and materials were used. The magnetic flux densities and magnetic forces as a function of components’ structure or material were analyzed to optimize the performances.

After the manufacturing of the packages with our innovative reflowable magnetic jig, the amount of warpage and shape of the package were inspected by Thermal Shadow Moire (TSM). The integrity of solder joints was inspected by X-ray and cross-section analyses. We have compared the warpage data of the packages using our innovative reflowable jig with those using a traditional reflowable jig. The experimental results show that the number of magnets and their configurations impact not only the local warpage but also the overall warpage. A reflowable jig with stronger magnetic force results in smaller warpage of the package. In conclusion, our innovative magnetic reflowable jig is a good method to control the warpage of these complex packages during the reflow process.
Design of Power Transistor Embedded in PCB Supported by 3D Simulations
Authors: Chvála Aleš , Marek Juraj , Šatka Alexander , Chen Jue
Published: November 2023

This paper presents an analysis and design of a power MOSFET transistor embedded in a printed circuit board (PCB). The analysis and design are supported by 3D electro-thermo-mechanical simulations. The analysis is focused on a comparison of the properties of a discrete power MOSFET transistor mounted on the surface of a PCB and a power MOSFET transistor embedded in a PCB. The conventional technology of packaged transistors exhibits significantly higher values of parasitic inductance, resistance, and thermal impedance compared to the embedded technology. 3D numerical finite element method simulations are effectively used for the design and optimization of the embedded technology in order to improve the electrical, thermal, and mechanical reliability performance of the device.
Prediction of the Localized Heating-Induced Size Effects in Semiconductors Based on the Heat Generation Characteristics and the Material Thermophysical Properties
Authors: Abdolhosseinzadeh Amir , Goktepe Emine , Donmezer Nazli
Published: November 2023

Localized heating can be encountered in the operation of transistors, light-emitting diodes, and some thermal spectroscopy techniques. Diffusive analytical and numerical thermal models are popularly used to characterize the thermal resistance of such problems. However, when there is localized heating comparable to the size of the mean free path of the energy carriers ballistic thermal transport, which causes additional thermal resistance is observed. The major objective of this study is to find a relation to describe the thermal resistances caused by the ballistic effects in problems with localized heating. Models based on the solution of the Fourier heat diffusion equation and the gray phonon Boltzmann Transport Equation (BTE) are solved simultaneously for to find this relation. It is observed that although phonon MFP and the power linearly effect the ballistic thermal resistance the effect of geometrical variables is more complicated and needs further analysis.
Design and Fabrication of an Inverter Module Co-Designed With the Busbar and Gate Driver
Authors: Roy Aishworya , DiMarino Christina , Miranda-Santos Jesi
Published: November 2023

In this work, a 1.7 kV, 300 A SiC MOSFET half-bridge power module is designed and fabricated contributing towards the target of achieving a 280–320 kW electric vehicle (EV) inverter assembly, targeting a 100 kW/L power density for commercial medium- and heavy-duty EVs. Co-designed with the busbar and gate driver, the custom power module emphasizes efficient heat dissipation, minimized parasitic inductance and a compact footprint. Key specifications to ensure optimal performance include an RDS,on below 20 mΩ, Rth,j–c under 0.2 K/W, and a switching time shorter than 20 ns. The module features a double-sided cooling sandwiched structure, an embedded thermistor for health and degradation monitoring and utilizes three Wolfspeed 3rd generation 1.7 kV, 18 mΩ dies per switch position. simulated power loop inductance is 14.5 nH, simulated parasitic resistance is 0.265 mΩ, and simulated junction-to-case thermal resistance is 0.12 °C/W per die. To keep the die temperature below 150°C, a cooling coefficient of 5500 W/m2 is necessary.
Line Width and Electrical Performance Prediction for Inkjet Printed Conductors-Resistors-Inductors-Capacitors
Authors: Lall Pradeep , Kulkarni Shriram , Soni Ved , Miller Scott
Published: November 2023

Inkjet printing enables the high-speed production of devices on a variety of substrates while offering an increased level of precision and repeatability. There is a need for closed-loop control over the printing process to achieve geometrical accuracy and consistent electrical performance of printed circuits and components. A sophisticated closed-loop control process can be achieved by establishing a relationship between printer input parameters and printed objects’ geometrical and electrical output. In this study, the impact of various printer settings on the electrical performance and geometrical accuracy of printed circuits and components has been studied. Specifically, the effect of print resolution, droplet size, and the number of copies on the electrical performance of printed resistors, planar inductors, and capacitors have been investigated. The printing was done using Particle-free silver ink on a Polyimide substrate. The statistical model developed from experimental data provides a means of achieving closed-loop control over the printing process.
Study of Sustained High-Temperature on the Reliability of Lead-Free Solder Joint Assemblies Under Vibration
Authors: Lall Pradeep , Mehta Vishal , Suhling Jeff , Locker David
Published: November 2023

Electronic parts in the automotive, downhole drilling of oil & gas, and aerospace sectors are frequently subjected to severe high strain loads. Those extreme loads may be occurring as a result of shocks, vibrations, and drop-impact circumstances. In addition, these parts are frequently exposed to severe low and high temperatures ranging from −65°C to 200°C. In such critical environment, these electronic equipment can be exposed to strain rates ranging from 1 to 100 per second. SAC solder alloys are the most often used alloys to replace tin-lead solders in electronic assembly applications. Tin, silver, and copper are the essential elements in these lead-free alloys. SAC solder alloys have proven to be successful in surface mount, wave soldering, and hand soldering applications. The primary advantage of RoHS certified lead-free solder is that it is safer than lead solder, which is a severe neurotoxic. Numerous doped solder alloys, such as SAC-Q, SAC-R, Innolot, M758 etc. have recently been introduced in electronic components. Mechanical characteristics and statistics for lead-free solder alloys are critical for enhancing electronic package durability at high temperatures and strain rates. Combined effects of higher temperatures and vibrations in electronic components might result in rapid failure. The majority of previous solder joint research has been on either vibrational stresses or thermal cycling for conventional solders like SAC105, and SAC305. SAC alloy failure mechanisms were investigated in this article at higher surrounding test temperatures up to 155°C, as well as at vibration loads of 5g and 10g levels. Harmonic vibrations at the first natural frequency was measured for the test boards with CABGA daisy-chained package at various test temperatures and vibration g-levels. Results on assembly response and resistance were collected utilizing high-speed data acquisition and highspeed imaging. A high-speed camera system was employed to catch the vibration event during testing. Stresses in solder interconnects were calculated using Finite Element Analysis simulation. The impact of g-levels, and operating temperatures on the hysteresis loop and plastic work density has been investigated. The failure mode analysis for the test board has been performed. Anand viscoplasticity material data for the solder alloys which were previously published by authors were used to capture the high-strain rate behavior and temperature dependent aging behavior of the solder junctions for FE analysis.
Variable Area Jet Impingement for High Voltage Power Electronics
Authors: Whitt Reece , Huitink David
Published: November 2023

Convective heat transfer by jet impingement cooling offers a suitable solution for these high heat flux applications. Compared to techniques that rely on bulk conduction in series with convection, direct liquid impingement reduces the thermal resistance between power device hot spots and the coolant. Although capable of highly efficient cooling, static impingement devices must be designed for the worst-case cooling requirements for a transient power profile, possibly resulting in a wasted hydraulic performance. Aircraft, highway vehicles, and heavy machinery fall into this category where a substantial factor of safety is required. This work proposes a method for improving power electronics reliability by limiting temperature fluctuations at reduced coolant pressure requirements during transient power cycling using a variable area jet. Single phase jet impingement cooling is implemented in an active control scheme using a variable diameter iris mechanism as the primary nozzle architecture. In addition to pressure drop and temperature control, the active nozzle structure introduces the ability to create pulsating jet flows to further enhance the heat transfer compared to fixed-geometry nozzles. The key underlying fluid mechanics characteristic of pulsating flows is the effect of disrupting the thermal boundary layer on the electrical device surface. By introducing a variable diameter jet, eddy formation can be fine-tuned for optimal boundary layer disruption. Using the definition of the Strouhal number, vortex shedding created by the non-steady jet flows is directly correlated with the resulting Nusselt number as a function of the iris kinematics. An experimental apparatus for jet impingement thermal-fluid testing is used to evaluate the Nusselt number versus Strouhal number for a parametric study of variable diameter iris configurations. The apparatus utilizes a voice coil actuator to achieve sine and square wave forms, varying amplitude of actuation, and varying mean of actuation. Finally, power cycling with a single emulated hot spot is performed to estimate the reliability increase as a result of maintaining constant junction temperatures with the active jet impingement scheme.
Parametric Studies of Flexible Sandwich Panels As a Compliant Fairing for Folding Wingtip Joints
Authors: Mahid Nuhaadh Mohamed , Schenk Mark , Titurus Branislav , Woods Benjamin King Sutton
Published: November 2023

This paper presents a parametric study into the design space of morphing fairings for the Semi-Aeroelastic Hinged (SAH) folding wing concept. The fairing will cover the angled hinge region of the wingtip with a smooth and continuous skin surface to reduce drag. It is made from flexible sandwich panels employing the Geometrically Anisotropic ThermOplastic Rubber (GATOR) morphing skin concept, with a chevron-based cellular core covered in elastomeric facesheets. A parametrically defined finite element analysis framework is established and used to explore the mechanical response of a three-dimensional wing fairing. The two design objectives are minimising torsional stiffness and out-of-plane deformation during the rotation of the underlying wingtip joint. A parameter sweep is used to establish correlations between the design variables and the competing objectives. Notable correlations were identified for the chevron wall angle, core thickness, facesheet thickness, fairing span, pre-strain and flare angle. Pre-straining the facesheets is found to delay the onset of large changes in surface curvature and the subsequent softening of stiffness. However, it also leads to higher levels of torque at large rotation angles. Overall, this study helps to elucidate the design trends for compliant fairings while also reducing the design space in preparation for further studies.