bluuebunny/crossref_metadata_2025 huggingface dataset:
Damage analysis of combined continuous and discontinuous thin‐ply carbon/glass hybrid composite using acoustic emission
Authors: Ichenihi Amos , Li Wei , Gao Yantao
Published: October 2021

Thin‐ply hybrid composite is an attractive technology for realizing high‐performance ductile composites (carbon and glass). However, the continuous carbon (CC) layers are limited to a thickness that can only emit small fracture energies to achieve pseudo‐ductility, compromising the mechanical performance of the laminates due to the low carbon/glass ratio. To solve this problem, four different lay‐up architectures of partially discontinuous carbon (DC) and angled carbon layers were coupled with continuous glass and carbon to increase the carbon/glass ratio maintaining pseudo‐ductility and improve mechanical properties. When under tensile loading, sandwiched DC layers with CC layers (H212) can achieve pseudo‐ductility with good mechanical properties compared to a sample with similar carbon layer thickness but with CC sandwiched by DC layers (H412). An improvement of 13% on the modulus and 2% on the yield strength is registered. Besides, acoustic emission (AE) analysis and sentry function are used to monitor the behavior of the respective damage mechanisms in the hybrid composites. The AE procedure used clustered the carbon and glass fiber breakages separately. Consequently, the sentry function analysis shows the damage mechanisms damage progression causing pseudo‐ductility.
Modeling thermo‐mechanical behaviors of carbon nanotube/polyurethane functionally graded shape memory polymer beam
Authors: Zhao Fei , Chen Yuqi , Zhou Bo , Li Yingjie , Xue Shifeng
Published: October 2021

In this paper, a new constitutive model which can model the thermo‐mechanical behaviors of functionally graded shape memory polymer (SMP) beam is established. The kinematic equation was established based on the SMP constitutive equation further derived and Euler–Bernoulli beam theory. The material parameter equations were established by taking the volume fraction of carbon nanotubes (CNT) as the gradient based on the material parameter equations of SMP and properties of functionally graded materials. According to the constitutive model, the simply supported beam was taken for example to be solved and simulated by using the virtual work principle. The results show material parameters properties, deflection properties, stress properties and shape memory properties of CNT/carbon nanotube/polyurethane (PU) functionally graded beam and some conclusions are concluded. This work shows the thermo‐mechanical behavior of CNT/PU functionally graded beam, and it provides a theoretical basis for the practical application of functionally graded SMP materials.
Mechanical properties enhancement in composite material structures of poly‐lactic acid/epoxy/milled glass fibers prepared by fused filament fabrication and solution casting
Authors: Mustafa Ammar , Aloyaydi Bandar , Subbarayan Sivsankaran , Al‐Mufadi Fahad A.
Published: October 2021

Additive manufacturing technology can help us to produce complex components/parts easily. It can be used to develop the parts with multi‐material structures consisting of thermoplastic, thermosetting plastic, and ceramic fibers. This multi‐material structure enhances the performance of lightweight polymer‐based components. In this research work, poly‐lactic acid (PLA) lattice (mono‐material structure), PLA lattice filled with epoxy (bi‐material structure), and PLA lattice incorporated with embedded milled glass fibers (MGFs) in an epoxy matrix (tri‐material structure, TMS) were designed and developed by fused filament fabrication and solution casting methods. PLA lattice of 50% volume was fixed in all structures and 50% volume was filled with epoxy and MGFs. The dispersed MGFs in epoxy matrix were varied from 0, 2.5, 5, and 7.5 vol%. The mechanical properties were carried out by compression test, three‐point bending test, and tensile test. The results revealed that 5 vol% of MGFs in the epoxy sample (TMS) exhibited improved mechanical performances compared to other samples. The cone‐beam CT scan results confirmed the voids/porous free surfaces in the developed materials. The high‐resolution scanning electron microscope microstructural evolutions in‐terms of topography and fractured regions were also examined and reported.
Validity of claims‐based algorithms to identify neurodevelopmental disorders in children
Authors: Straub Loreen , Bateman Brian T. , Hernandez‐Diaz Sonia , York Cassandra , Zhu Yanmin , Suarez Elizabeth A. , Lester Barry , Gonzalez Lyndon , Hanson Ryan , Hildebrandt Clara , Homsi Joseph , Kang Daniel , Lee Ken W. K. , Lee Zachary , Li Linda , Longacre Mckenna , Shah Nidhi , Tukan Natalie , Wallace Frances , Williams Christina , Zerriny Salim , Mogun Helen , Huybrechts Krista F.
Published: October 2021

Purpose

To validate healthcare claim‐based algorithms for neurodevelopmental disorders (NDD) in children using medical records as the reference.

Methods

Using a clinical data warehouse of patients receiving outpatient or inpatient care at two hospitals in Boston, we identified children (≤14 years between 2010 and 2014) with at least one of the following NDDs according to claims‐based algorithms: autism spectrum disorder/pervasive developmental disorder (ASD), attention deficit disorder/other hyperkinetic syndromes of childhood (ADHD), learning disability, speech/language disorder, developmental coordination disorder (DCD), intellectual disability, and behavioral disorder. Fifty cases per outcome were randomly sampled and their medical records were independently reviewed by two physicians to adjudicate the outcome presence. Positive predictive values (PPVs) and 95% confidence intervals (CIs) were calculated.

Results

PPVs were 94% (95% CI, 83%–99%) for ASD, 88% (76%–95%) for ADHD, 98% (89%–100%) for learning disability, 98% (89%–100%) for speech/language disorder, 82% (69%–91%) for intellectual disability, and 92% (81%–98%) for behavioral disorder. A total of 19 of the 50 algorithm‐based cases of DCD were confirmed as severe coordination disorders with functional impairment, with a PPV of 38% (25%–53%). Among the 31 false‐positive cases of DCD were 7 children with coordination deficits that did not persist throughout childhood, 7 with visual‐motor integration deficits, 12 with coordination issues due to an underlying medical condition and 5 with ADHD and at least one other severe NDD.

Conclusions

PPVs were generally high (range: 82%–98%), suggesting that claims‐based algorithms can be used to study NDDs. For DCD, additional criteria are needed to improve the classification of true cases.
A study of rheological properties of cellulose diacetate in acetone solution at low and high shear rates
Authors: Su Riting , Yu Xing , Yang Zhanping , Huang Haijian , Liang Yinchun
Published: October 2021

The rheological properties of cellulose diacetate (CDA) with different intrinsic viscosity (IV) and different concentration in acetone solutions were studied at low and high shear rates. The zero‐shear viscosity increased and the structural index increased, when the IV of CDA was increased or the acetone solution concentration was increased. Evidence suggested that a sulfate structure may be forming. It is shown that the increase of hemicellulose and sulfur content is associated with an increase of chain entanglements between CDA molecules and the abnormal increase of solution zero‐shear viscosity. At a high shear rate, the correlation curve between inlet pressure drop and solution concentration obtained by Bagley method analysis shows an inflection point, which appears to be the critical concentration at which the cellulose diacetate molecular chains in the solution form a long range entangled elastic network. After the concentration exceeds a certain range of above critical points, the entanglement of the molecular chains in the solution is significantly enhanced. The zero shear viscosity inflection point concentration calculated by the rheological curve with low shear velocity and the inlet pressure drop inflection point concentration calculated by the capillary rheological calculation have good consistency.
Wet leakage resistance development of modules with various backsheet types
Authors: Buerhop Claudia , Stroyuk Oleksandr , Zöcklein Julian , Pickel Tobias , Hauch Jens , Peters Ian Marius
Published: October 2021

Over the last years, a significant number of inverter shutdowns most likely due to degraded backsheets have been reported by operators, investors, and manufacturers. We investigated water ingress into different backsheets, and the resulting risk for inverter shutdowns. For studying pending insulation issues of inverters, we analyzed exemplarily a 5‐MWp photovoltaic (PV) power station with 20,530 PV modules and 314 inverters. For backsheet identification on‐site near‐infrared absorption spectroscopic measurements of 518 PV modules from 20 inverters were carried out. In the lab, wet leakage tests provide kinetic data of insulation resistances for different backsheet materials. Historic ground impedance data logged by the inverter were evaluated to show the temporal evolution of inverters with different backsheets. We observe different kinetics and drops in leakage resistance for different backsheet types based on polyamide (PA) and air‐side fluorinated coating (FC), and distinguish between two types of behavior. “PA‐like” is characterized by moderate leakage resistance loss and slower performance reduction with regard to insulation in the field. “FC‐like” is characterized by high susceptibility to water and a high leakage resistance loss rate for PV modules after 6–8 years of operation. These characteristics are indicated when measuring inverter GI in dependence of temperature and humidity. For PA‐based BSs, the reduction in ground impedance (GI) is steady over 8 years. We observe incidences with GI below the critical value of 400 kΩ on 2.8% of all days. For FC‐based BSs, we also observe steady decrease of average GI initially, yet after 6 years in the field, we see a sudden and rapid decline for 20% of those inverters. GI falling below the critical value is observed on up to 5% of all days, with the trend increasing. Therefore we, expect this problem to become even more severe for longer operating times.
The association between teacher‐student relationship and academic achievement: The moderating effect of parental involvement
Authors: Ma Lihong , Liu Jian , Li Banban
Published: October 2021

As an important part of adolescents' social capital, teacher‐student relationship (TSR) and parental involvement (PI) are important for student learning. However, we know little about how PI works with TSR in relation to adolescents' learning outcomes. The present study aimed to examine the association between TSR and adolescents' learning outcomes in China, as well as testing the potential moderating role of PI. Participants were 332 fourth graders and 321 eleventh graders from Shandong province, China. Student‐perceived TSR and home‐based PI, and curriculum‐based measures of academic achievement were collected in October 2019. The major findings of the study included: (1) TSR and students' academic performance positively correlate with each other; (2) PI moderates the relationship between TSR and students' academic performance; (3) High PI in primary school reduces the impacts of lower TSR on student performance; (4) High PI in secondary school has no compensating effect on low TSR, but it still reduces the influence of TSR on academic performance. The present research verifies and extends the association between TSR and academic achievement to parental factors, and holds substantive theoretical and practical implications for teacher education and family education research.
Registration of the Coda/Brundage wheat recombinant inbred line mapping population
Authors: Zemetra Robert S. , Phipps Savannah N. , Koehler Thomas , Burke Adrienne B. , Carter Arron H.
Published: October 2021

A mapping population (Reg. no. MP‐15, NSL 540708 MAP) composed of a cross between the soft white common winter wheat (Triticum aestivum L. subsp. aestivum) ‘Brundage’ (PI 599193) and the soft white club winter wheat (T. aestivum L. subsp. compactum) ‘Coda’ (PI 594372) was developed to maximize diversity within the soft white market class. The population comprises 268 F6:7 lines developed through single seed descent. The genetic linkage map consists of 2,144 DNA markers and is assigned to 32 linkage groups covering all chromosomes except 1D. This population was initially developed to determine additional markers linked to the Pch1 gene in wheat. It has further been used to identify quantitative trait loci (QTL) associated with resistance to other diseases such as Cephalosporium stripe (caused by Cephalosporium gramineum) and stripe rust (caused by Puccinia striiformis Westend. f. sp. tritici Erikss). The mapping population has also been used for identification of DNA markers associated with freezing tolerance, end‐use quality, and the compactum locus. From the differences in traits between the parental lines, the Coda/Brundage population provides the opportunity for further inquiry into the genes behind the identified QTL. The parents have only been phenotypically screened for a limited number of traits, and further screening may identify more polymorphic traits which the population can be used to map. It can also serve as a validation population for marker‐trait associations identified in other populations or other genetic studies such as recombination frequency.
Percutaneous treatments for residual and/or phantom limb pain in adults with lower‐extremity amputations: A narrative review
Authors: Sperry Beau P. , Cheney Cole W. , Kuo Keith T. , Clements Nathan , Burnham Taylor , Conger Aaron , Cushman Daniel M. , McCormick Zachary L.
Published: October 2021

Residual limb pain (RLP) and phantom limb pain (PLP) profoundly affect the lives of many individuals who have undergone lower‐ or upper‐extremity amputation. Despite the considerable impact of RLP/PLP on quality of life in persons with amputation, there have been few attempts to evaluate the efficacy of percutaneous interventions in the treatment of RLP and/or PLP. This narrative review evaluates the effectiveness of percutaneous treatments for RLP and/or PLP in patients after lower‐extremity amputation. Peripheral nerve stimulation, alcohol neurolysis, conventional thermal radiofrequency ablation, perineural corticosteroid injection, botulinum toxin injection, and etanercept injection were associated with varying success rates. Wide confidence intervals and small treatment cohorts impede assessments of overall success. High‐quality studies of nonsurgical, percutaneous treatments for RLP and/or PLP are lacking. Well‐designed randomized controlled trials and large cohort studies with comparison groups using validated outcomes are needed to determine the effectiveness of nonsurgical interventions for the treatment of RLP and PLP.
Playing construction with the monomer toy box for the synthesis of multi‐stimuli responsive copolymers by reversible deactivation radical polymerization protocols
Authors: D'Acunzo Francesca , Masci Giancarlo
Published: October 2021

In this review article, we survey the 2016–June 2021 scientific literature on the synthesis of multi‐stimuli responsive (MSR) polymers, the main focus being on reversible deactivation radical polymerization techniques (RDRPs, also known as controlled radical polymerizations). In fact, along more than 40 years of extensive research, RDRPs have boosted the synthesis of stimuli‐responsive polymers. RDRPs are now robust, versatile, relatively user‐friendly and even interconvertible, thus allowing control over composition, sequence, and topology of polymers. Such control can afford materials with well‐defined responses to physical, chemical, and biological external stimuli. Furthermore, “click” reactions are used to combine macromolecular precursors or to introduce specific functional groups in the target structure. As a result, MSR polymers are obtained from diverse combinations of commercial or specially synthesized building blocks arranged at will into desired sequences and architectures. Thanks to this versatility, self‐assembling polymeric structures are designed either to respond to triggers and perform specific applicative tasks, or to investigate the influence of structural variables on the responsivity of polymers. The “green” trend emerging in the field of responsive polymers and RDRPs is also briefly discussed.
Discerning torquoselectivity in a series of cyclobutene ring‐opening reactions using quantum theory of atoms in molecules and stress tensor
Authors: Momen Roya , Azizi Alireza , Morales‐Bayuelo Alejandro , Pazhoohesh Mehdi , Ji Xiaobo
Published: October 2021

This study aims to investigate the phenomenon of torquoselectivity through four thermal cyclobutenes ring‐opening reactions including 1‐chlorocyclobut‐1‐ene (Reaction 1), 3‐chloro‐4‐methylcyclobut‐1‐ene (Reaction 2), 3‐methoxy‐4‐methylcyclobut‐1‐ene (Reaction 3), and finally 3‐chloro‐4‐methoxycyclobut‐1‐ene (Reaction 4). Despite the limitation of conventional methods in which just considers activation energies within transition state theory, this research focuses on the nature of the chemical bond, electronic reorganization, and predicting either non‐competitive or competitive reactions within quantum theory of atoms in molecules (QTAIM) and stress tensor frameworks. Various theoretical analyses for these reactions such as metallicity ξ(rb), ellipticity ε, total local energy density H(rb), stress tensor polarizability ℙσ, stress tensor eigenvalue λ3σ, bond‐path length, and path lengths H display differently for non‐competitive and competitive reactions as well as for the conrotatory preferences either it is the transition state outward conrotatory (TSOC) or transition state inward conrotatory (TSIC) directions by presenting degeneracy or non‐degeneracy in their results. Results illustrate that the preference of TSOC or TSIC of these thermal ring‐opening reactions could obtain from path lengths H of the ring‐opening bonds, where the longer one apparently predicts the preference. In addition, examinations indicate that Reaction 1 is competitive and Reactions (2–4) are non‐competitive reactions with TSOC, TSOC, and TSIC preference directions respectively. The concordant results of stress tensor and QTAIM scalar and vectors with experimental results provide a better understanding of all reactions mechanism.
Robotic harvesting of the occluded fruits with a precise shape and position reconstruction approach
Authors: Gong Liang , Wang Wenjie , Wang Tao , Liu Chengliang
Published: October 2021

Occlusion is one of the key factors affecting the success rate of vision‐based fruit‐picking robots. It is important to accurately locate and grasp the occluded fruit in field applications, However, there is yet no universal and effective solution. In this paper, a high‐precision estimation method of spatial geometric features of occluded targets based on deep learning and multisource images is presented, enabling the selective harvest robot to envision the whole target fruit as if its occlusions do not exist. First, RGB, depth and infrared images are acquired. And pixel‐level matched RGB‐D‐I fusion images are obtained by image registration. Second, aiming at the problem of detecting the occluded tomatoes in the greenhouse, an extended Mask‐RCNN network is designed to extract the target tomato. The target segmentation accuracy is improved by 7.6%. Then, for partially occluded tomatoes, a shape and position restoration method is used to recover the obscured tomato. This algorithm can extract tomato radius and centroid coordinates directly from the restored depth image. The mean Intersection over Union is 0.895, and the centroid position error is 0.62 mm for the occluded rate under 25% and the illuminance between 1 and 12 KLux. And hereby a dual‐arm robotic harvesting system is improved to achieve a picking time of 11 s per fruit, an average gripping accuracy of 8.21 mm, and an average picking success rate of 73.04%. The proposed approach realizes a high‐fidelity geometrics reconstruction instead of mere image style restoration, which endows the robot with the ability to see through obstacles in the field scenes and improves its operational success rate in its result.
Tracking clusters and anomalies in evolving data streams
Authors: Guggilam Sreelekha , Chandola Varun , Patra Abani
Published: October 2021

Data‐driven anomaly detection methods typically build a model for the normal behavior of the target system, and score each data instance with respect to this model. A threshold is invariably needed to identify data instances with high (or low) scores as anomalies. This presents a practical limitation on the applicability of such methods, since most methods are sensitive to the choice of the threshold, and it is challenging to set optimal thresholds. The issue is exacerbated in a streaming scenario, where the optimal thresholds vary with time. We present a probabilistic framework to explicitly model the normal and anomalous behaviors and probabilistically reason about the data. An extreme value theory based formulation is proposed to model the anomalous behavior as the extremes of the normal behavior. As a specific instantiation, a joint nonparametric clustering and anomaly detection algorithm (INCAD) is proposed that models the normal behavior as a Dirichlet process mixture model. Results on a variety of datasets, including streaming data, show that the proposed method provides effective and simultaneous clustering and anomaly detection without requiring strong initialization and threshold parameters.
Electrostatic Stabilization of Nano Liquid Metals in Doped Nonpolar Liquids
Authors: Kim Jieun , Jeong Jinwon , Hyun Youngbin , Chung Sang Kug , Lee Joohyung
Published: October 2021

Liquid metals and alloys are attracting renewed attention owing to their potential for application in various advanced technologies. Eutectic gallium‐indium (EGaIn) has been focused on in particular because of its integrated advantages of high conductivity, low melting point, and low toxicity. In this study, the colloidal behavior of nano‐dispersed EGaIn in nonpolar oils is investigated. Although the nonpolar oil continuous phase is commonly considered to be free of electric charges, electrostatic repulsion appears to be crucial in the colloidal stabilization of the nano‐dispersed EGaIn phases, the modulation of which is possible by doping the oil phases with different types of oil‐soluble surfactants. The qualitative correlation between the observed colloidal stabilities and the “zero field” particle mobilities inferred from the field‐dependent electrophoretic mobilities indicates that the electric charging of EGaIn particles in surfactant‐doped nonpolar oils is a static phenomenon that is maintained in equilibrium, rather than a solely field‐induced process. A systematic investigation of the charging properties of these unique biphasic particles, consisting of the liquid Ga‐In bulk and the solid Ga2O3 surface that formed spontaneously, reveals the complicated system‐dependent nature of the charging mechanisms mediated by ionic and nonionic surfactants in nonpolar media.
Low Optical Writing Energy Multibit Optoelectronic Memory Based on SnS2/h‐BN/Graphene Heterostructure
Authors: Gao Feng , Zhang Xin , Tan Biying , Zhang Shichao , Zhang Jia , Jia Dechang , Zhou Yu , Hu PingAn
Published: October 2021

With the rapid development of artificial intelligence and neural network computing, the requirement for information storage in computing is gradually increasing. Floating gate memories based on 2D materials has outstanding characteristics such as non‐volatility, optical writing, and optical storage, suitable for application in photonic in‐memory computing chips. Notably, the optoelectronic memory requires less optical writing energy, which means lower power consumption and greater storage levels. Here, the authors report an optoelectronic memory based on SnS2/h‐BN/graphene heterostructure with an extremely low photo‐generated hole tunneling barrier of 0.23 eV. This non‐volatile multibit floating gate memory shows a high switching ratio of 106 and a large memory window range of 64.8 V in the gate range ±40 V. And the memory device can achieve multilevel storage states of 50 under a low power light pulses of 0.32 nW and small light pulse width of 50 ms. Thanks to the Fowler–Nordheim tunneling of the photo‐generated holes, the optical writing energy of the optoelectronic memory has been successfully reduced by one to three orders of magnitude compared to existing 2D materials‐based systems.
Business ethics in China and Iceland—Contrasts and convergence
Authors: Sigurjonsson Throstur Olaf , Arnardottir Audur Arna , Jiao Hao , Zhu Yunxia , Schwarzkopf David
Published: October 2021

It is generally accepted that cultural differences affect individuals' approaches to ethics, but how are the effects of culture manifested in perceptions of ethics? Further, how are cultural differences displayed in such ethics‐related actions as recommendations for business ethics education? Managers' responses from two starkly different cultures, China and Iceland, reveal, somewhat surprisingly, that one group's top business ethics concerns and business ethics education recommendations are at the bottom of the other group's rankings, and vice‐versa, yet each appears reasonable given the cultural background. This shows how nuanced the expression of cultural differences in the realm of ethics can be and how potential practical steps may rely on perceived “top” ethical issues. Together, these findings imply that there is more to explore about the role of culture on ethical reasoning and behavior than researchers have examined to date. We provide suggestions for further research and practical applications.
QTL for seed shattering and threshability in intermediate wheatgrass align closely with well‐studied orthologs from wheat, barley, and rice
Authors: Altendorf Kayla R. , DeHaan Lee R. , Larson Steve R. , Anderson James A.
Published: October 2021

Perennial grain crops have the potential to improve agricultural sustainability but few existing species produce sufficient grain yield to be economically viable. The outcrossing, allohexaploid, and perennial forage species intermediate wheatgrass (IWG) [Thinopyrum intermedium (Host) Barkworth & D. R. Dewey] has shown promise in undergoing direct domestication as a perennial grain crop using phenotypic and genomic selection. However, decades of selection will be required to achieve yields on par with annual small‐grain crops. Marker‐aided selection could accelerate progress if important genomic regions associated with domestication were identified. Here we use the IWG nested association mapping (NAM) population, with 1,168 F1 progeny across 10 families to dissect the genetic control of brittle rachis, floret shattering, and threshability. We used a genome‐wide association study (GWAS) with 8,003 single nucleotide polymorphism (SNP) markers and linkage mapping—both within‐family and combined across families—with a robust phenotypic dataset collected from four unique year‐by‐location combinations. A total of 29 quantitative trait loci (QTL) using GWAS and 20 using the combined linkage analysis were detected, and most large‐effect QTL were in common across the two analysis methods. We reveal that the genetic control of these traits in IWG is complex, with significant QTL across multiple chromosomes, sometimes within and across homoeologous groups and effects that vary depending on the family. In some cases, these QTL align within 216 bp to 31 Mbp of BLAST hits for known domestication genes in related species and may serve as precise targets of selection and directions for further study to advance the domestication of IWG.
Closer contact with students can pay off in enrollment, retention
Authors: Enos Gary A.
Published: October 2021

No one should underestimate the importance of offering a personal touch when working with students who may face multiple barriers to enrollment and completion, said the Vice President of Enrollment Management and Student Success at Monroe County Community College in Michigan. Scott Behrens, Ph.D., still finds the phone calls he places to students to be among his favorite aspects of the job.
Solutions to Plastic Pollution: A Conceptual Framework to Tackle a Wicked Problem
Authors: Wagner Martin
Published: October 2021

There is a broad willingness to act on global plastic pollution as well as a plethora of available technological, governance, and societal solutions. However, this solution space has not been organized in a larger conceptual framework yet. In this essay, I propose such a framework, place the available solutions in it, and use it to explore the value-laden issues that motivate the diverse problem formulations and the preferences for certain solutions by certain actors. To set the scene, I argue that plastic pollution shares the key features of wicked problems, namely, scientific, political, and societal complexity and uncertainty as well as a diversity in the views of actors. To explore the latter, plastic pollution can be framed as a waste, resource, economic, societal, or systemic problem. Doing so results in different and sometimes conflicting sets of preferred solutions, including improving waste management; recycling and reuse; implementing levies, taxes, and bans as well as ethical consumerism; raising awareness; and a transition to a circular economy. Deciding which of these solutions is desirable is, again, not a purely rational choice. Accordingly, the social deliberations on these solution sets can be organized across four scales of change. At the geographic and time scales, we need to clarify where and when we want to solve the plastic problem. On the scale of responsibility, we need to clarify who is accountable, has the means to make change, and carries the costs. At the magnitude scale, we need to discuss which level of change we desire on a spectrum of status quo to revolution. All these issues are inherently linked to value judgments and worldviews that must, therefore, be part of an open and inclusive debate to facilitate solving the wicked problem of plastic pollution.
Evaluating Microplastic Experimental Design and Exposure Studies in Aquatic Organisms
Authors: Adhikari Puspa L. , Bam Wokil , Campbell Pamela L. , Oberhaensli Francois , Metian Marc , Besson Marc , Jacob Hugo , Swarzenski Peter W.
Published: October 2021

Environmental microplastic particles (MPs) represent a potential threat to many aquatic animals, and experimental exposure studies, when done well, offer a quantitative approach to assess this stress systematically and reliably. While the scientific literature on MP studies in aquatic environments is rapidly growing, there is still much to learn, and this chapter presents a brief overview of some of the successful methods and pitfalls in experimental MP exposure studies. A short overview of some experimental design types and recommendations are also presented. A proper experimental exposure study will yield useful information on MP-organism impacts and must include the following: a comprehensive MP characterization (e.g., density, buoyancy, type, nature, size, shape, concentration, color, degree of weathering/biofilm formation, an assessment of co-contaminant/surfactant toxicity and behavior, an understanding exposure modes, dose and duration, and the type and life stage of the target species). Finally, more conventional experimental considerations, such as time, costs, and access to clean water, specialized instrumentation, and use of appropriate controls, replicate, and robust statistical analyses are also vital. This short review is intended as a necessary first step towards standardization of experimental MP exposure protocols so one can more reliably assess the transport and fate of MP in the aquatic environment as well as their potential impacts on aquatic organisms.
Marine Microplastics and Seafood: Implications for Food Security
Authors: Lundebye Anne-Katrine , Lusher Amy L. , Bank Michael S.
Published: October 2021

Seafood is an important food source, and this chapter addresses the food safety concerns related to plastic particles in different seafood. Here we focus on those species which are commonly consumed by humans, such as bivalves, gastropods, cephalopods, echinoderms, crustaceans, and finfish. The objectives of this chapter are to (1) outline the major sources, fate, and transport dynamics of microplastics in marine ecosystems, (2) provide a critical assessment and synthesis of microplastics in seafood taxa commonly consumed by humans, (3) discuss the implications of microplastics with regard to human health risk assessments, and (4) suggest future research priorities and recommendations for assessing microplastics in marine ecosystems in the context of global food security and ocean and human health.
Ecotoxicological Impacts of Micro- and Nanoplastics in Terrestrial and Aquatic Environments
Authors: Gomes Tânia , Bour Agathe , Coutris Claire , Almeida Ana Catarina , Bråte Inger Lise , Wolf Raoul , Bank Michael S. , Lusher Amy L.
Published: October 2021

Plastic pollution is a widespread environmental problem that is currently one of the most discussed issues by scientists, policymakers and society at large. The potential ecotoxicological effects of plastic particles in a wide range of organisms have been investigated in a growing number of exposure studies over the past years. Nonetheless, many questions still remain regarding the overall effects of microplastics and nanoplastics on organisms from different ecosystem compartments, as well as the underlying mechanisms behind the observed toxicity. This chapter provides a comprehensive literature review on the ecotoxicological impacts of microplastics and nanoplastics in terrestrial and aquatic organisms in the context of particle characteristics, interactive toxicological effects, taxonomic gradients and with a focus on synergies with associated chemicals. Overall, a total of 220 references were reviewed for their fulfilment of specific quality criteria (e.g. experimental design, particle characteristics, ecotoxicological endpoints and findings), after which 175 were included in our assessment. The analysis of the reviewed studies revealed that organisms’ responses were overall influenced by the physicochemical heterogeneity of the plastic particles used, for which distinct differences were attributed to polymer type, size, morphology and surface alterations. On the other hand, little attention has been paid to the role of additive chemicals in the overall toxicity. There is still little consistency regarding the biological impacts posed by plastic particles, with observed ecotoxicological effects being highly dependent on the environmental compartment assessed and specific morphological, physiological and behavioural traits of the species used. Nonetheless, evidence exists of impacts across successive levels of biological organization, covering effects from the subcellular level up to the ecosystem level. This review presents the important research gaps concerning the ecotoxicological impacts of plastic particles in different taxonomical groups, as well as recommendations on future research priorities needed to better understand the ecological risks of plastic particles in terrestrial and aquatic environments.
Dietary Exposure to Additives and Sorbed Contaminants from Ingested Microplastic Particles Through the Consumption of Fisheries and Aquaculture Products
Authors: Garrido Gamarro Esther , Costanzo Violetta
Published: October 2021

Microplastics and nanoplastics may be found in the gastrointestinal tract of some aquatic animals and could potentially be ingested by humans if consumed whole. Information on the toxicity of plastic particles, as well as co-contaminants such as plastic additives, remains scarce. This represents a serious challenge to perform realistic risk assessments. An exposure assessment of selected plastic additives and co-contaminants of known toxicity associated with microplastics was carried out for shellfish in this study, which builds on an exposure assessment of microplastic additives and a limited number of associated contaminants in mussels conducted by the FAO in 2017. This study evaluates possible impacts to food safety by examining a diverse additives and associated sorbed contaminants. The results suggest that the levels of certain microplastic additives and sorbed co-contaminants in target animals (shrimp, prawns, clams, oysters, and mussels) do not pose a food safety threat to consumers. To get to further conclusions, an exposure assessment from the whole diet should be carried out and the toxicity of some of the most common polymers and plastic additives, as well as their mixtures, needs to be carefully evaluated.
Next-to-MHV Yang-Mills kinematic algebra
Authors: Chen Gang , Johansson Henrik , Teng Fei , Wang Tianheng
Published: October 2021

Abstract

Kinematic numerators of Yang-Mills scattering amplitudes possess a rich Lie algebraic structure that suggest the existence of a hidden infinite-dimensional kinematic algebra. Explicitly realizing such a kinematic algebra is a longstanding open problem that only has had partial success for simple helicity sectors. In past work, we introduced a framework using tensor currents and fusion rules to generate BCJ numerators of a special subsector of NMHV amplitudes in Yang-Mills theory. Here we enlarge the scope and explicitly realize a kinematic algebra for all NMHV amplitudes. Master numerators are obtained directly from the algebraic rules and through commutators and kinematic Jacobi identities other numerators can be generated. Inspecting the output of the algebra, we conjecture a closed-form expression for the master BCJ numerator up to any multiplicity. We also introduce a new method, based on group algebra of the permutation group, to solve for the generalized gauge freedom of BCJ numerators. It uses the recently introducedbinary BCJ relationsto provide a complete set of NMHV kinematic numerators that consist ofpure gauge.
Baryogenesis via relativistic bubble walls
Authors: Azatov Aleksandr , Vanvlasselaer Miguel , Yin Wen
Published: October 2021

Abstract

We present a novel mechanism which leads to the baryon asymmetry generation during the strong first order phase transition. If the bubble wall propagates with ultra-relativistic velocity, it has been shown [1] that it can produce states much heavier than the scale of the transition and that those states are then out of equilibrium. In this paper, we show that this production mechanism can also induce CP-violation at one-loop level. We calculate those CP violating effects during the heavy particle production and show, that combined with baryon number violating interactions, those can lead to successful baryogenesis. Two models based on this mechanism are constructed and their phenomenology is discussed. Stochastic gravitational wave signals turn out to be generic signatures of this type of models.
One-loop corrections to the Higgs boson invisible decay in the dark doublet phase of the N2HDM
Authors: Azevedo Duarte , Gabriel Pedro , Mühlleitner Margarete , Sakurai Kodai , Santos Rui
Published: October 2021

Abstract

The Higgs invisible decay width may soon become a powerful tool to probe extensions of the Standard Model with dark matter candidates at the Large Hadron Collider. In this work, we calculate the next-to-leading order (NLO) electroweak corrections to the 125 GeV Higgs decay width into two dark matter particles. The model is the next-to-minimal 2-Higgs-doublet model (N2HDM) in the dark doublet phase, that is, only one doublet and the singlet acquire vacuum expectation values. We show that the present measurement of the Higgs invisible branching ratio, BR(H → invisible < 0.11), does not lead to constraints on the parameter space of the model at leading order. This is due to the very precise measurements of the Higgs couplings but could change in the near future. Furthermore, if NLO corrections are required not to be unphysically large, no limits on the parameter space can be extracted from the NLO results.
The NSVZ relations for $$ \mathcal{N} $$ = 1 supersymmetric theories with multiple gauge couplings
Authors: Korneev D. S. , Plotnikov D. V. , Stepanyantz K. V. , Tereshina N. A.
Published: October 2021

Abstract

We investigate the NSVZ relations for $$ \mathcal{N} $$
N
= 1 supersymmetric gauge theories with multiple gauge couplings. As examples, we consider MSSM and the flipped SU(5) model, for which they easily reproduce the results for the two-loop β-functions. For $$ \mathcal{N} $$
N
= 1 SQCD interacting with the Abelian gauge superfield we demonstrate that the NSVZ-like equation for the Adler D-function follows from the NSVZ relations. Also we derive all-loop equations describing how the NSVZ equations for theories with multiple gauge couplings change under finite renormalizations. They allow describing a continuous set of NSVZ schemes in which the exact NSVZ β-functions are valid for all gauge coupling constants. Very likely, this class includes the HD+MSL scheme, which is obtained if a theory is regularized by Higher covariant Derivatives and divergences are removed by Minimal Subtractions of Logarithms. That is why we also discuss how one can construct the higher derivative regularization for theories with multiple gauge couplings. Presumably, this regularization allows to derive the NSVZ equations for such theories in all loops. In this paper we make the first step of this derivation, namely, the NSVZ equations for theories with multiple gauge couplings are rewritten in a new form which relates the β-functions to the anomalous dimensions of the quantum gauge superfields, of the Faddeev-Popov ghosts, and of the matter superfields. The equivalence of this new form to the original NSVZ relations follows from the extension of the non-renormalization theorem for the triple gauge-ghost vertices, which is also derived in this paper.
Non-perturbative determination of collisional broadening and medium induced radiation in QCD plasmas
Authors: Moore Guy D. , Schlichting Sören , Schlusser Niels , Soudi Ismail
Published: October 2021

Abstract

We supply recently obtained results from lattice EQCD with the correct UV limit to construct the collisional broadening kernel C(b⊥) in a QCD plasma. We discuss the limiting behavior of C(b⊥) at small and large impact parameters b⊥, and illustrate how the results can be used to compute medium-induced radiation rates.
Next-to-leading power two-loop soft functions for the Drell-Yan process at threshold
Authors: Broggio Alessandro , Jaskiewicz Sebastian , Vernazza Leonardo
Published: October 2021

Abstract

We calculate the generalized soft functions at $$ \mathcal{O} $$
O
($$ {\alpha}_s^2 $$

α
s
2

) at next-to-leading power accuracy for the Drell-Yan process at threshold. The operator definitions of these objects contain explicit insertions of soft gauge and matter fields, giving rise to a dependence on additional convolution variables with respect to the leading power result. These soft functions constitute the last missing ingredient for the validation of the bare factorization theorem to NNLO accuracy. We carry out the calculations by reducing the soft squared amplitudes into a set of canonical master integrals and we employ the method of differential equations to evaluate them. We retain the exact d-dimensional dependence of the convolution variables at the integration boundaries in order to regulate the fixed-order convolution integrals. After combining the soft functions with the relevant collinear functions, we perform checks of the results at the cross-section level against the literature and expansion-by-regions calculations, at NNLO and partly at N3LO, finding agreement.
Symmetry-resolved entanglement entropy in Wess-Zumino-Witten models
Authors: Calabrese Pasquale , Dubail Jérôme , Murciano Sara
Published: October 2021

Abstract

We consider the problem of the decomposition of the Rényi entanglement entropies in theories with a non-abelian symmetry by doing a thorough analysis of Wess-Zumino-Witten (WZW) models. We first consider SU(2)k as a case study and then generalise to an arbitrary non-abelian Lie group. We find that at leading order in the subsystem size L the entanglement is equally distributed among the different sectors labelled by the irreducible representation of the associated algebra. We also identify the leading term that breaks this equipartition: it does not depend on L but only on the dimension of the representation. Moreover, a log log L contribution to the Rényi entropies exhibits a universal prefactor equal to half the dimension of the Lie group.
First results of the CAST-RADES haloscope search for axions at 34.67 μeV
Authors: Álvarez Melcón A. , Arguedas Cuendis S. , Baier J. , Barth K. , Bräuninger H. , Calatroni S. , Cantatore G. , Caspers F. , Castel J. F. , Cetin S. A. , Cogollos C. , Dafni T. , Davenport M. , Dermenev A. , Desch K. , Díaz-Morcillo A. , Döbrich B. , Fischer H. , Funk W. , Gallego J. D. , García Barceló J. M. , Gardikiotis A. , Garza J. G. , Gimeno B. , Gninenko S. , Golm J. , Hasinoff M. D. , Hoffmann D. H. H. , Irastorza I. G. , Jakovčić K. , Kaminski J. , Karuza M. , Lakić B. , Laurent J. M. , Lozano-Guerrero A. J. , Luzón G. , Malbrunot C. , Maroudas M. , Miralda-Escudé J. , Mirallas H. , Miceli L. , Navarro P. , Ozbey A. , Özbozduman K. , Peña Garay C. , Pivovaroff M. J. , Redondo J. , Ruz J. , Ruiz Chóliz E. , Schmidt S. , Schumann M. , Semertzidis Y. K. , Solanki S. K. , Stewart L. , Tsagris I. , Vafeiadis T. , Vogel J. K. , Widmann E. , Wuensch W. , Zioutas K.
Published: October 2021

Abstract

We present results of the Relic Axion Dark-Matter Exploratory Setup (RADES), a detector which is part of the CERN Axion Solar Telescope (CAST), searching for axion dark matter in the 34.67 μeV mass range. A radio frequency cavity consisting of 5 sub-cavities coupled by inductive irises took physics data inside the CAST dipole magnet for the first time using this filter-like haloscope geometry. An exclusion limit with a 95% credibility level on the axion-photon coupling constant of gaγ ≳ 4 × 10−13 GeV−1 over a mass range of 34.6738 μeV < ma< 34.6771 μeV is set. This constitutes a significant improvement over the current strongest limit set by CAST at this mass and is at the same time one of the most sensitive direct searches for an axion dark matter candidate above the mass of 25 μeV. The results also demonstrate the feasibility of exploring a wider mass range around the value probed by CAST-RADES in this work using similar coherent resonant cavities.
The unbearable lightness of charged gravitini
Authors: Dall’Agata Gianguido , Emelin Maxim , Farakos Fotis , Morittu Matteo
Published: October 2021

Abstract

We prove that charged gravitini cannot have parametrically small or vanishing Lagrangian mass in de Sitter vacua of extended supergravity while respecting the magnetic weak gravity conjecture. This places large classes of de Sitter solutions of gauged supergravity in the swampland, including all known stable solutions of the N=2 theory. We illustrate this result by analyzing a variety of de Sitter critical points of N=2 matter-coupled supergravity that also include new stable de Sitter solutions. Our results provide concrete evidence that (quasi) de Sitter with charged light gravitini should belong to the swampland, which also strongly resonates with the “festina lente” bound.