bluuebunny/crossref_metadata_2025 huggingface dataset:
3D Carbiyne Nanospheres Boosting Excellent Lithium and Sodium Storage Performance
Authors: Lu Tiantian , Deng Xin , Sun Quanhu , Xiao Jinchong , He Jianjiang , Wang Kun , Huang Changshui
Published: December 2021

Reasonable design of electrode materials with specific morphology and structure can efficiently improve the metal ions storage and transmission properties of metal ion batteries. Here the preparation of spirobifluorene‐based three‐dimensional carbiyne nanosphere (SBFCY‐NS) that is composed of spirobifluorene (SBF) and alkyne bonds is reported. Benefiting from the rigid spatial structure of SBF, numerous precursors are coupled through the connection of acetylene bonds, extending to form solid nanospheres. Abundant storage spaces and convenient multi‐directional transmission paths for metal ions are available inside the three‐dimensional (3D) carbiyne structure. Thus, SBFCY‐NS is applied as efficient anode for lithium‐ion battery and sodium‐ion battery. The good stability of SBFCY‐NS‐based electrode and its improved Coulombic efficiency can be attributed to the special morphology of nanospheres, which can easily form thin and stable solid electrolyte interface film on the surface. Those results further promote the preparation of spherical carbon‐based materials with abundant pores that can be applied in the field of electrodes.
Allocation of COVID‐19 testing budget on a commute network of counties
Authors: Huang Yaxuan , Ke Zheng Tracy , Jin Jiashun
Published: December 2021

The screening testing is an effective tool to control the early spread of an infectious disease such as COVID‐19. When the total testing capacity is limited, we aim to optimally allocate testing resources among n counties. We build a (weighted) commute network on counties, with the weight between two counties a decreasing function of their traffic distance. We introduce a network‐based disease model, in which the number of newly confirmed cases of each county depends on the numbers of hidden cases of all counties on the network. Our proposed testing allocation strategy first uses historical data to learn model parameters and then decides the testing rates for all counties by solving an optimization problem. We apply the method on the commute networks of Massachusetts, USA and Hubei, China, and observe its advantages over testing allocation strategies that ignore the network structure. Our approach can also be extended to study the vaccine allocation problem.
Material and residual stress improvement in S355 welded structural steel using mechanical and thermal post‐weld treatment methods
Authors: Al‐Karawi Hassan
Published: December 2021

Welding is by far the most widely used metal joining method. High‐Frequency Mechanical Impact (HFMI) treatment and Tungsten Inert Gas (TIG) remelting are two post‐weld treatment methods that aim to enhance the strength of the steel. In this paper, the improvement in residual stress and material characteristic obtained with these methods are studied by conducting several experimental investigations such as hole drilling, hardness testing and microscopy. Hole drilling shows that HFMI treatment improves the status of residual stress at the weld toe in the first 1 mm from the surface. Furthermore, Vickers testing shows a remarkable improvement in the hardness values at the weld toe in the first 2 mm. This can be attributed to the reduction in grain size after treatment. Moreover, acicular ferrite and tempered bainite are found to be the main constituents in the fusion and heat‐affected zones after TIG‐remelting.
Experimental study on the tensile response of post‐installed adhesive anchor connections in reinforced and plain concrete beams
Authors: Sartipi Sahand , Emrani Seyed Mohammad Reza , Epackachi Siamak , Erfani Saeed
Published: December 2021

Post‐installed connections are widely used in the rehabilitation, strengthening, and expansion of existing concrete structures. These connections accommodate the connecting of new elements to old concrete using post‐installed anchoring techniques. Attachment of new segments to concrete beams and columns requires the installation of anchors in slim concrete components. Under this condition, the behavior of connection is severely affected by the small width of concrete elements. Additionally, the behavior of anchors is influenced by the confining effects of stirrups in reinforced concrete elements. In this paper, the tensile behavior of chemical anchor connections in single and group formations of four and six anchors is investigated using the results of 36 individual experiments of adhesive anchors installed in plain and reinforced concrete beams. The key design parameters are embedment depth, section width, and effects of the reinforcement. The results indicate high levels of interaction between all studied parameters. The tensile capacities of the single and groups of anchors are compared against ACI 318 predictions. The main effects of parameters, as well as their interactions, are analyzed and discussed. Based on the test results, several recommendations are provided for the installation of adhesive bonded anchors in narrow concrete components.
Corrigendum: Transition Metal‐Free Synthesis of Carbo‐ and Heterocycles via Reaction of Alkynes with Organylchalcogenides
Authors: Zeni Gilson , Godoi Benhur , Jurinic Carla K. , Belladona Andrei L. , Schumacher Ricardo F.
Published: December 2021

Previously, this article was inadvertently assigned to issue 6, 2021 with incorrect page numbers. The article now has been moved to the correct issue number 10, 2021 – special issue on 18th Brazilian Meeting on Organic Synthesis – for which it is part of. This correction does not affect the DOI number of the paper. The publisher apologies for the oversight and any inconvenience caused.
Exploring the evolution of professional identity formation in health professions education
Authors: Moseley Lindsey E. , McConnell Lauren , Garza Kimberly B. , Ford Channing R.
Published: December 2021

This article provides a general overview of professional identity formation (PIF) in health professions education, a summary of relevant theories related to PIF, and a description of pedagogical models which promote PIF.
Hepatitis D virus (HDV) prevalence in Austria is low but causes considerable morbidity due to fast progression to cirrhosis
Authors: Jachs Mathias , Binter Teresa , Schmidbauer Caroline , Hartl Lukas , Strasser Michael , Laferl Hermann , Hametner‐Schreil Stephanie , Lindorfer Alexander , Dax Kristina , Stauber Rudolf E. , Kessler Harald H. , Bernhofer Sebastian , Maieron Andreas , Loacker Lorin , Bota Simona , Santonja Isabel , Munda Petra , Mandorfer Mattias , Peck‐Radosavljevic Markus , Holzmann Heidemarie , Gschwantler Michael , Zoller Heinz , Ferenci Peter , Reiberger Thomas
Published: December 2021

Background

Hepatitis D virus (HDV) coinfection aggravates the course of hepatitis B virus (HBV). The prevalence of HDV in Austria is unknown.

Objective

This national study aimed at (i) recording the prevalence of HDV‐infection in Austria and (ii) characterizing the “active” HDV cohort in Austria.

Methods

A total of 10 hepatitis treatment centers in Austria participated in this multicenter study and retrospectively collected their HDV patients between Q1/2010 and Q4/2020. Positive anti‐HDV and/or HDV‐RNA‐polymerase chain reaction (PCR) results were retrieved from local database queries. Disease severity was assessed by individual chart review. Viremic HDV patients with clinical visits in/after Q1/2019 were considered as the “active” HDV cohort.

Results

A total of 347 anti‐HDV positive patients were identified. In 202 (58.2%) patients, HDV‐RNA‐PCR test was performed, and 126/202 (62.4%) had confirmed viremia. Hepatocellular carcinoma was diagnosed in 7 (5.6%) patients, 7 (5.6%) patients underwent liver transplantation, and 11 (8.7%) patients died during follow‐up. The “active” Austrian HDV cohort included 74 (58.7%) patients: Evidence for advanced chronic liver disease (ACLD, i.e., histological F3/F4 fibrosis, liver stiffness ≥10 kPa, varices, or hepatic venous pressure gradient ≥6 mmHg) was detected in 38 (51.4%) patients, including 2 (5.3%) with decompensation (ascites/hepatic encephalopathy). About 37 (50.0%) patients of the “active” HDV cohort had previously received interferon treatment. Treatment with the sodium‐taurocholate cotransporting polypeptide inhibitor bulevirtide was initiated in 20 (27.0%) patients.

Conclusion

The number of confirmed HDV viremic cases in Austria is low (<1% of HBV patients) but potentially underestimated. Testing all HBV patients will increase the diagnostic yield. More than half of viremic HDV patients had ACLD. Improved HDV testing and workup strategies will facilitate access to novel antiviral therapies.
Effects of alkalinity addition with different strategies on CANON process: Start‐up, performance, and microbial community
Authors: Liu Guangqing , Zhou Xiaohua , Liang Huili , Han Liming , Qiao Zhuangming , Su Bensheng
Published: December 2021

The effects of alkalinity addition with different strategies on the start‐up, performance, and microbial community of completely autotrophic nitrogen removal over nitrite (CANON) were investigated over 450 days. In phase I, the alkalinity was increased gradually from 300 to 2,000 mg/L to obtain the optimal range. In phase II, the reactor was restarted to verify the appropriate alkalinity value of 1,600 mg/L. The fact that it only took 90 days (phase I: 170 days) to complete the start‐up of CANON in phase II demonstrated that an alkalinity value of 1,600 mg/L was suitable when the influent NH4+‐N concentration was 200 mg/L (alkalinity/NH4+‐N = 8:1). The slope (k = 2.00) of NH4+‐N concentration decrease in phase II during the start‐up process was significantly higher than that in phase I (k = 1.50). High removal efficiencies of NH4+‐N (98%) and TN (80%) were attained in both phases. Specific anaerobic ammonium oxidation (anammox) activity tests showed that the anammox activity of the two phases reached 3.31 and 5.31 mg TN/(g VSS·h), respectively. High‐throughput sequencing analysis revealed that appropriate alkalinity could promote the enrichment of Candidatus Brocadia, C. Jettenia, and C. Kuenenia (total abundance of 31.96%) while effectively inhibiting Nitrospira (abundance of less than 0.50%).

Practitioner Points

An alkalinity/NH4+‐N ratio of 8 promoted the rapid start‐up and stable performance of CANON.

NH4+‐N and TN removal efficiencies of 98% and 80%, respectively, were obtained.

High alkalinity promoted the enrichment of Candidatus Brocadia, Candidatus Jettenia, Candidatus Kuenenia and inhibited Nitrospira.
The Waring Worlds of H. G. Wells: The Entangled Histories of Education, Sociobiology, Post-genomics, and Science Fiction
Authors: Adsit-Morris Chessa
Published: December 2021

Drawing on H. G. Wells’ visionary texts, social critique, and revolutionary insights, this chapter revisits and recontextualizes questions raised by Wells almost a century ago around the adequacy of science education curricula to grapple with the still unfolding Anthropocene. Exploring the technological advances in molecular biology that have occurred over the last twenty years, which have instigated an epistemological turn toward what many science studies scholars are calling the post-genomic era, this chapter situates current education research and policy debates within the post-genomic era through new research in the field of sociobiology. Conversely, drawing on the fundamental reconceptualization of inheritance that underlies genomic research in the post-genomic era, this chapter argues for a similar reconceptualization of intelligence, educational attainment, cognition, and learning. The chapter concludes by exploring the potential of a transnational and transknowledge extended synthesis within education, one that encourages critical examination of the impact of globalization, nationalism, and capitalism on science education and works to imagine how science education can be reformed, reimagined, and reconfigured to contribute to the radical actualization of a just, equitable, and sustainable world.
Decolonizing Healing Through Indigenous Ways of Knowing
Authors: Field Miranda
Published: December 2021

The field of psychology is embarking on a process to interrupt the historical, colonial cycle of harm and beginning to work with and alongside Indigenous communities to understand the healing journey. From an Indigenous lens, healing incorporates more than the physical recovery; physical, emotional, mental, and spiritual healing exists through learning, which occurs along the healing journey. This healing journey has no definite beginning or end, and as we begin to move away from pathologizing healing to a strength-based healing process, the focus shifts to relationships—relationships with self, community, more-than-human, and the land. This chapter proposes that to decolonize Western healing processes, as a field, we must acknowledge the coexistence of learning during the healing journey. Building healing capacity through learning elucidates the understanding of the past, the needs of the present, and lays foundations for the future to work towards restoring integrity and prompting balanced care.
Introduction
Authors: Frankot Edda
Published: December 2021

This chapter discusses the aims and objectives of the study, a short historiography, a justification of the study’s delimitations and the book’s structure.
Punishment in Late Medieval Kampen
Authors: Frankot Edda
Published: December 2021

This chapter provides an overview of punishment in late medieval Kampen in order to provide a context for the use of banishment. It discusses various punishments utilised in Kampen, such as symbolic, shameful, corporal and capital punishments, fines and imprisonment, as well as some of the town’s officials involved in punishment.
Redemption: The Repayment of Fines and the Reintegration of Exiles
Authors: Frankot Edda
Published: December 2021

The second of two main chapters, this analyses the redemption of exiles and what this can tell us about the values of late medieval Kampen society concerning morally acceptable behaviour. The first section concerns the practical aspects around the reintegration of banished individuals from all categories, whereas the second section focuses specifically on the financial arrangements between exiles and magistrates which allowed the former to return to Kampen. The final section discusses the links between debt and morality, in order to establish whether defaulting public debtors were banished because they were considered to have displayed immoral behaviour.
Looking for (and not finding) a bulk brane
Authors: Reeves Wyatt , Rozali Moshe , Simidzija Petar , Sully James , Waddell Christopher , Wakeham David
Published: December 2021

Abstract

When does a holographic CFT with a boundary added to it (a BCFT) also have a ‘good’ holographic dual with a localized gravitating end-of-the-world brane? We argue that the answer to this question is almost never. By studying Lorentzian BCFT correlators, we characterize constraints imposed on a BCFT by the existence of a bulk causal structure. We argue that approximate ‘bulk brane’ singularities place restrictive constraints on the spectrum of a BCFT that are not expected to be true generically. We discuss how similar constraints implied by bulk causality might apply in higher-dimensional holographic descriptions of BCFTs involving a degenerating internal space. We suggest (although do not prove) that even these higher-dimensional holographic duals are not generic.
Bethe ansatz for quantum-deformed strings
Authors: Seibold Fiona K. , Sfondrini Alessandro
Published: December 2021

Abstract

Two distinct η-deformations of strings on AdS5×S5 can be defined; both amount to integrable quantum deformations of the string non-linear sigma model, but only one is itself a superstring background. In this paper we compare their conjectured all-loop worldsheet S matrices and derive the corresponding Bethe equations. We find that, while the S matrices are apparently different, they lead to the same Bethe equations. Moreover, in either case the eigenvalues of the transfer matrix, which encode the conserved charges of each system, also coincide. We conclude that the integrable structure underlying the two constructions is essentially the same. Finally, we write down the full Bethe-Yang equations describing the asymptotic spectrum of the superstring background.
Analysis of W± + 4γ in the 2HDM Type-I at the LHC
Authors: Wang Yan , Arhrib A. , Benbrik R. , Krab M. , Manaut B. , Moretti S. , Yan Qi-Shu
Published: December 2021

Abstract

We analyse a light charged Higgs boson in the 2-Higgs Doublet Model (2HDM) Type-I, when its mass satisfies the condition MH±< Mt + Mb and the parameter space is consistent with theoretical requirements of self-consistency as well as the latest experimental constraints from Large Hadron Collider (LHC) and other data. Over such a parameter space, wherein the Standard Model (SM)-like state discovered at the LHC in 2012 is the heaviest CP-even state of the 2HDM, it is found that the decay modes of the charged Higgs boson are dominated by H±→ W±(∗)h. Furthermore, the light neutral Higgs boson h dominantly decays into two photons. Under these conditions, we find that the production and decay process pp → H±h → W±(∗)hh → ℓνℓ + 4γ (ℓ = e, μ) is essentially background free. However, since the W±(∗) could be largely off-shell and the h state is very light, so that both the lepton coming from the former and the photons coming from the latter could be rather soft, we perform here a full Monte Carlo (MC) analysis at the detector level demonstrating that such a W± + 4γ signal is very promising, as it would be yielding significant excesses at the LHC with an integrated luminosity of L = 300 fb−1 at both $$ \sqrt{s} $$

s

= 13 and 14 TeV.
Changing selection into full-time work and its effect on wage inequality in Germany
Authors: Fitzenberger Bernd , de Lazzer Jakob
Published: December 2021

To explore whether changes in the selection into full-time work among German men were a driver in the rise in wage inequality since the mid-1990s, we propose a modification of selection-corrected quantile regressions. Addressing Huber and Melly’s (J Appl Econom 30(7):1144–1168, 2015) concerns, this modification allows us to estimate the effects of selection with respect to both observables and unobservables. Our findings show that those employed in 1995 would have had lower wages in 2010 than those employed in 2010 and wage dispersion would have been higher, suggesting that full-time workers have become less heterogeneous over time.
PET imaging of reactive astrocytes in neurological disorders
Authors: Liu Yu , Jiang Han , Qin Xiyi , Tian Mei , Zhang Hong
Published: December 2021

The reactive astrocytes manifest molecular, structural, and functional remodeling in injury, infection, or diseases of the CNS, which play a critical role in the pathological mechanism of neurological diseases. A growing need exists for dependable approach to better characterize the activation of astrocyte in vivo. As an advanced molecular imaging technology, positron emission tomography (PET) has the potential for visualizing biological activities at the cellular levels. In the review, we summarized the PET visualization strategies for reactive astrocytes and discussed the applications of astrocyte PET imaging in neurological diseases. Future studies are needed to pay more attention to the development of specific imaging agents for astrocytes and further improve our exploration of reactive astrocytes in various diseases.
Radionuclide imaging of apoptosis for clinical application
Authors: Qin Xiyi , Jiang Han , Liu Yu , Zhang Hong , Tian Mei
Published: December 2021

Apoptosis was a natural, non-inflammatory, energy-dependent form of programmed cell death (PCD) that can be discovered in a variety of physiological and pathological processes. Based on its characteristic biochemical changes, a great number of apoptosis probes for single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have been developed. Radionuclide imaging with these tracers were potential for the repetitive and selective detection of apoptotic cell death in vivo, without the need for invasive biopsy. In this review, we overviewed molecular mechanism and specific biochemical changes in apoptotic cells and summarized the existing tracers that have been used in clinical trials as well as their potentialities and limitations. Particularly, we highlighted the clinic applications of apoptosis imaging as diagnostic markers, early-response indicators, and prognostic predictors in multiple disease fields.
New solution procedures for the order picker routing problem in U-shaped pick areas with a movable depot
Authors: Diefenbach Heiko , Emde Simon , Glock Christoph H. , Grosse Eric H.
Published: December 2021

This paper develops new solution procedures for the order picker routing problem in U-shaped order picking zones with a movable depot, which has so far only been solved using simple heuristics. The paper presents the first exact solution approach, based on combinatorial Benders decomposition, as well as a heuristic approach based on dynamic programming that extends the idea of the venerable sweep algorithm. In a computational study, we demonstrate that the exact approach can solve small instances well, while the heuristic dynamic programming approach is fast and exhibits an average optimality gap close to zero in all test instances. Moreover, we investigate the influence of various storage assignment policies from the literature and compare them to a newly derived policy that is shown to be advantageous under certain circumstances. Secondly, we investigate the effects of having a movable depot compared to a fixed one and the influence of the effort to move the depot.
Full characterization of a phase-locked DUV double pulse generated in an all-reflective shaping setup working under grazing incidence in a broad spectral range
Authors: Hartwell S. , Azima A. , Haunhorst C. , Kazemi M. , Namboodiri M. , Przystawik A. , Schwickert D. , Skruszewicz S. , Kip D. , Drescher M. , Laarmann T.
Published: December 2021

Controlling the temporal and spectral properties of ultrashort laser pulses in the visible and near-infrared spectral range by means of a femtosecond pulse-shaping device is a powerful tool with many applications in ultrafast spectroscopy. A major and successful concept is known as the 4f design, which has a symmetric zero-dispersion-compressor geometry. Most 4f pulse shapers rely on using transmissive optics in their beam path limiting the operational wavelength ranges. In the present contribution, we use an all-reflective shaping setup to generate a phase-locked 266 nm double pulse to benchmark its performance in the limit of short wavelengths. The setup comprises the complete spectral amplitude and phase diagnostics for quantitative analysis of the pulse properties before and after the shaper using the technique of frequency-resolved optical gating. The measured time–frequency spectra are in good agreement with optical simulations. The geometry and hardware of the device including the optical components are designed, such that all harmonics of the deep UV pulses travel the same path, giving the instrument the ability to work with soft X-ray pulses, under vacuum conditions, down to the few-nanometer wavelength scale.
Rules and regulations for a pregnant endourologist: the European perspective
Authors: Juliebø-Jones Patrick , Pietropaolo Amelia , Spinoit Anne-Francoise , Bergesen Anne K. , Guðbrandsdottir Gigja , Beisland Christian , von Ostau Nicola , Harke Nina N. , Ribal Maria J. , Zerva Maria , Bres-Niewada Ewa , Zondervan Patricia , McLornan Liza , Ferretti Stefania , Tonnhofer Ursula , Necknig Ulrike Hendrika , Skolarikos Andreas , Somani Bhaskar K.
Published: December 2021

Introduction

Working in surgery while pregnant is challenging. Navigating this period safely is of paramount importance. Anecdotal observation suggests that there exists great variation among European nations in regard to maternity leave and radiation safety.

The aim of this article was to gain insight into policy patterns and variations across Europe regarding these issues.

Methods

A series of core question items was distributed to representatives across 12 nations Austria, Belgium, Germany, Greece, Iceland, Italy, Netherlands, Norway, Poland, Republic of Ireland, Spain and the United Kingdom).

Results

The total number of weeks with full pay ranged from as little as 4 weeks in Belgium to 32 and Iceland. All countries included in this study give the option of additional weeks beyond the initial period, however at reduced pay. Some offer unpaid leave beyond this. Only 5/12 countries had a specific policy on when the pregnant surgeon should come off the on-call rota. Only Austria, Italy and Poland stipulate a requirement for the pregnant clinician to be replaced or be completely exempt in cases involving radiation. Only Germany, Iceland, Norway and Poland highlight the need to limit radiation dose in the first trimester. Beyond this, Germany alone provides written guidance for reduction in gown weight and along with Poland, display arguably the most forward-thinking approach to resting.

Conclusion

There is a marked range in maternal leave policies across Europe. There also exists a lack of universal guidance on radiation safety for the pregnant urologist. There is urgent need for this void to be addressed.
Is there evidence behind pre- or perioperative cognitive training in gynaecological patients on the prevention of perioperative cognitive dysfunction? A review
Authors: Volz Sophia , Koch Franziska , Dayan Davud , Upadhyay Miriam , Otto Stephanie , Schochter Fabienne , Janni Wolfgang , Ebner Florian
Published: December 2021

Purpose

Perioperative cognitive dysfunction can be observed in all age groups of patients. Sometimes, this is more stressful to the patient than the actual surgical wound. Enhanced recovery after surgery pathways screen for patients at risk and lead to early post-surgical intervention. To prevent cognitive dysfunction, a prehabilitation approach might be useful.

Methods

This systematic literature review provides an overview on the current knowledge on prehabilitation for cognitive dysfunction for gynaecological patients by searching the National Library of Medicine (PubMed) in February 2020 to identify publications regarding presurgical cognitive training with three different search terms.

Results

501 articles were identified and after screening for eligibility five were left for further analysis. Generally, cognitive function is split into several cognitive aspects like anxiety or memory, speed, attention, flexibility or problem-solving functions. Each of these aspects can/need to be trained to show an improvement after general anaesthesia. Training possibilities range from relaxation methods via music, one-on-one personal training sessions to electronically supported training units.

Conclusion

Prehabilitation of the cognitive function can be split in different cognitive domains. Each of these domains seem to be influenced by training. The training itself can be based on applications or known relaxation methods or even old-fashioned board games. The evidence is, however, still low and there is a need for further studies.
Speech perception and hearing effort using a new active middle ear implant audio processor
Authors: Rahne Torsten , Fröhlich Laura , Wagner Luise , Kropp Miriam Hannah , Müller Alexander
Published: December 2021

Purpose

The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA.

Method

Fifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES.

Results

Both audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA.

Conclusion

The SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.
Homogenization of fully nonlinear rod lattice structures: on the size of the RVE and micro structural instabilities
Authors: Herrnböck Ludwig , Steinmann Paul
Published: December 2021

This work investigates the possibility of applying two-scale computational homogenization to rod lattice structures emerging, for instance, from additive manufacturing. The influence of the number of unit cells within the representative volume element (RVE), thus, the RVE’s size on the homogenized mechanical response is studied for occurring microscopic structural instabilities. Therein, the macro-scale, described in terms of three-dimensional continuum mechanics, is coupled to the micro-scale described by geometrically exact rods, enabling arbitrary large deformations and rotations. A special feature of the presented framework is that the rods building the lattice structures are not restricted to deform purely elastically but may deform inelastically. The mechanical response of lattice structures is investigated by applying the developed homogenization method to an exemplary lattice. Under special loads the structure reaches an instable state and may buckle. The appearance of instabilities depends on the geometric properties of the lattice’s underlying rods and the RVE’s size.
On finite element implementation of cyclic elastoplasticity: theory, coding, and exemplary problems
Authors: Suchocki Cyprian
Published: December 2021

In this work the finite element (FE) implementation of the small strain cyclic plasticity is discussed. The family of elastoplastic constitutive models is considered which uses the mixed, kinematic-isotropic hardening rule. It is assumed that the kinematic hardening is governed by the Armstrong–Frederick law. The radial return mapping algorithm is utilized to discretize the general form of the constitutive equation. A relation for the consistent elastoplastic tangent operator is derived. To the best of the author’s knowledge, this formula has not been presented in the literature yet. The obtained set of equations can be used to implement the cyclic plasticity models into numerous commercial or non-commercial FE packages. A user subroutine UMAT (User’s MATerial) has been developed in order to implement the cyclic plasticity model by Yoshida into the open-source FE program CalculiX. The coding is included in the Appendix. It can be easily modified to implement any isotropic hardening rule for which the yield stress is a function of the effective plastic strain. The number of the utilized backstress variables can be easily increased as well. Several validation tests which have been performed in order to verify the code’s performance are discussed.
Nitrate reduction potential of a fractured Middle Triassic carbonate aquifer in Southwest Germany
Authors: Osenbrück Karsten , Blendinger Eva , Leven Carsten , Rügner Hermann , Finkel Michael , Jakus Natalia , Schulz Hartmut , Grathwohl Peter
Published: December 2021

Nitrate reduction constitutes an important natural mechanism to mitigate the widespread and persistent nitrate contamination of groundwater resources. In fractured aquifers, however, the abundance and accessibility of electron donors and their spatial correlation with groundwater flow paths are often poorly understood. In this study, the nitrate reduction potential of a fractured carbonate aquifer in the Upper Muschelkalk of SW Germany was investigated, where denitrification is due to the oxidation of ferrous iron and reduced sulfur. Petrographical analyses of rock samples revealed concentrations of syn-sedimentary and diagenetically formed pyrite ranging from 1 to 4 wt.% with only small differences between different facies types. Additional ferrous iron is available in saddle dolomites (up to 2.6 wt.%), which probably were formed by tectonically induced percolation of low-temperature hydrothermal fluids. Borehole logging at groundwater wells (flowmeter, video, gamma) indicates that most groundwater flow occurs along karstified bedding planes partly located within dolomites of the shoal and backshoal facies. The high porosity (15–30%) of these facies facilitates molecular diffusive exchange of solutes between flow paths in the fractures and the reactive minerals in the pore matrix. The high-porosity facies together with hydraulically active fractures featuring pyrite or saddle dolomite precipitates constitute the zones of highest nitrate reduction potential within the aquifer. Model-based estimates of electron acceptor/donor balances indicate that the nitrate reduction potential protecting water supply wells increases with increasing porosity of the rock matrix and decreases with increasing hydraulic conductivity (or effective fracture aperture) and spacing of the fracture network.
Convex generalized Nash equilibrium problems and polynomial optimization
Authors: Nie Jiawang , Tang Xindong
Published: December 2021

This paper studies convex generalized Nash equilibrium problems that are given by polynomials. We use rational and parametric expressions for Lagrange multipliers to formulate efficient polynomial optimization for computing generalized Nash equilibria (GNEs). The Moment-SOS hierarchy of semidefinite relaxations are used to solve the polynomial optimization. Under some general assumptions, we prove the method can find a GNE if there exists one, or detect nonexistence of GNEs. Numerical experiments are presented to show the efficiency of the method.
Clausal embedding in Washo: Complementation vs. modification
Authors: Bochnak M. Ryan , Hanink Emily A.
Published: December 2021

This paper concerns clausal embedding in Washo (also spelled Washoe, Wáˑšiw), a highly endangered Hokan/isolate language spoken around Lake Tahoe in the United States. We argue that Washo offers evidence that both complementation and modification are available strategies for subordination, and in doing so contribute more generally to the ongoing debate about how clauses are embedded by attitude verbs. We observe that the embedding strategies of certain predicates in Washo follow from independent properties of clause types in the language. On the one hand, clauses embedded by presuppositional verbs come in the form of clausal nominalizations, which are selected as thematic internal arguments. The DP layer in these complements is responsible for encoding familiarity in a general sense (along the lines of Kastner 2015) both in these complement clauses as well as in other constructions in the language. On the other hand, clauses embedded by non-presuppositional verbs are not selected at all; they are instead adjunct modifiers, which follows from the fact that the attitude verbs they modify are always intransitive. This aspect of the analysis lends support to the property-analysis of ‘that’-clauses (e.g., Kratzer 2006; Moulton 2009; Elliott 2016), but only in certain instances of embedding. We argue that the Washo facts show that selection still plays a role for some verbs, contra theories that do away with it altogether (Elliott 2016), but selection cannot explain everything either, as non-presuppositional verbs are intransitive and do not select at all.
Noch immer nicht angekommen? – Strukturelle Geschlechterungleichheit im Deutschen Bundestag
Authors: Bieber Ina E.
Published: December 2021

Trotz formaler Gleichstellung sind Frauen im Deutschen Bundestag immer noch unterrepräsentiert. Forschungsergebnisse legen nahe, dass institutionelle Faktoren entscheidend zur strukturellen Diskriminierung von Frauen in der Politik beitragen. Vor allem Mehrheitswahlsysteme und im rechten Parteispektrum verortete Parteien führen weltweit und auch in Deutschland zu niedrigen Frauenanteilen in den Parlamenten. Vor dem Hintergrund der anstehenden Wahlrechtsreform des Bundestags – deren Auftrag es auch ist, eine „[…] gleichberechtigte Repräsentanz von Frauen und Männern auf den Kandidatenlisten und im Bundestag zu erreichen“ – untersucht der Artikel, welche strukturellen Faktoren die Wahlchancen von Frauen bei Bundestagswahlen beeinflusst haben. Besonderes Augenmerk wird dabei auf die Auswirkungen des Wahlsystems und der ideologischen Ausrichtung der Parteien gelegt. Der verwendete Datensatz umfasst Kandidatinnen und Kandidaten bei Bundestagswahlen von 1953–2017. Damit ermöglicht er Analysen auf Individualebene, die auch die Untersuchung der Nominierungsqualität berücksichtigen, also der individuellen Erfolgschancen einer Kandidatur. Die Ergebnisse des Papiers zeigen, dass der Mechanismus des Mehrheitswahlrechts, aber auch die Qualität der Nominierung und die Parteizugehörigkeit die Wahlchancen von Frauen beeinflussen und somit Stellschrauben sind, um den Frauenanteil im Bundestag langfristig zu erhöhen.
Pollution in the Arctic Ocean: An overview of multiple pressures and implications for ecosystem services
Authors: Townhill Bryony L. , Reppas-Chrysovitsinos Efstathios , Sühring Roxana , Halsall Crispin J. , Mengo Elena , Sanders Tina , Dähnke Kirsten , Crabeck Odile , Kaiser Jan , Birchenough Silvana N. R.
Published: December 2021

The Arctic is undergoing unprecedented change. Observations and models demonstrate significant perturbations to the physical and biological systems. Arctic species and ecosystems, particularly in the marine environment, are subject to a wide range of pressures from human activities, including exposure to a complex mixture of pollutants, climate change and fishing activity. These pressures affect the ecosystem services that the Arctic provides. Current international policies are attempting to support sustainable exploitation of Arctic resources with a view to balancing human wellbeing and environmental protection. However, assessments of the potential combined impacts of human activities are limited by data, particularly related to pollutants, a limited understanding of physical and biological processes, and single policies that are limited to ecosystem-level actions. This manuscript considers how, when combined, a suite of existing tools can be used to assess the impacts of pollutants in combination with other anthropogenic pressures on Arctic ecosystems, and on the services that these ecosystems provide. Recommendations are made for the advancement of targeted Arctic research to inform environmental practices and regulatory decisions.
The value of transhumance for biodiversity conservation: Vulture foraging in relation to livestock movements
Authors: Aguilera-Alcalá Natividad , Arrondo Eneko , Pascual-Rico Roberto , Morales-Reyes Zebensui , Gil-Sánchez José M. , Donázar José A. , Moleón Marcos , Sánchez-Zapata José A.
Published: December 2021

In recent decades, intensive techniques of livestock raising have flourished, which has largely replaced traditional farming practices such as transhumance. These changes may have affected scavengers’ behaviour and ecology, as extensive livestock is a key source of carrion. This study evaluates the spatial responses of avian scavengers to the seasonal movements of transhumant herds in south-eastern Spain. We surveyed the abundance of avian scavengers and ungulates, and analysed the factors affecting the space use by 30 GPS-tracked griffon vultures (Gyps fulvus). Griffons’ foraging activity increased in the pasturelands occupied by transhumant herds, which implied greater vulture abundance at the landscape level during the livestock season. In contrast, facultative scavengers were more abundant without transhumant livestock herds, and the abundance of wild ungulates did not change in relation to livestock presence. We conclude that fostering transhumance and other traditional farming systems, to the detriment of farming intensification, could favour vulture conservation.
Physical activity as a determinant of successful aging: a narrative review article
Authors: Szychowska Agnieszka , Drygas Wojciech
Published: December 2021

Population of older people in many countries is constantly growing, therefore the subject of successful aging has become important and a priority for public health policy-makers. A person who is successfully aging has low risk of chronic disease and disability, high physical function, good mental health and social engagement in older age. Lifestyle factors, such as diet and exercise, have been identified as determinants of successful aging. The aim of this narrative review is to compile the evidence from big cohort studies on the overall health of older people. Their results indicate that regular physical activity increases the chances of successful aging in older people, but only after reaching a sufficient threshold. Physical activity lowers the risk of many chronic diseases and cognitive decline commonly associated with older age, promotes social engagement and improves self-estimated well-being.
Hastily formed knowledge networks and distributed situation awareness for collaborative robotics
Authors: Doherty Patrick , Berger Cyrille , Rudol Piotr , Wzorek Mariusz
Published: December 2021

In the context of collaborative robotics, distributed situation awareness is essential for supporting collective intelligence in teams of robots and human agents where it can be used for both individual and collective decision support. This is particularly important in applications pertaining to emergency rescue and crisis management. During operational missions, data and knowledge are gathered incrementally and in different ways by heterogeneous robots and humans. We describe this as the creation ofHastily Formed Knowledge Networks(HFKNs). The focus of this paper is the specification and prototyping of a general distributed system architecture that supports the creation of HFKNs by teams of robots and humans. The information collected ranges from low-level sensor data to high-level semantic knowledge, the latter represented in part as RDF Graphs. The framework includes a synchronization protocol and associated algorithms that allow for the automatic distribution and sharing of data and knowledge between agents. This is done through the distributed synchronization of RDF Graphs shared between agents. High-level semantic queries specified in SPARQL can be used by robots and humans alike to acquire both knowledge and data content from team members. The system is empirically validated and complexity results of the proposed algorithms are provided. Additionally, a field robotics case study is described, where a 3D mapping mission has been executed using several UAVs in a collaborative emergency rescue scenario while using the full HFKN Framework.
On the equidistribution of unstable curves for pseudo-Anosov diffeomorphisms of compact surfaces
Authors: FORNI GIOVANNI
Published: December 2021

We prove that the asymptotics of ergodic integrals along an invariant foliation of a toral Anosov diffeomorphism, or of a pseudo-Anosov diffeomorphism on a compact orientable surface of higher genus, is determined (up to a logarithmic error) by the action of the diffeomorphism on the cohomology of the surface. As a consequence of our argument and of the results of Giulietti and Liverani [Parabolic dynamics and anisotropic Banach spaces. J. Eur. Math. Soc. (JEMS)21(9) (2019), 2793–2858] on horospherical averages, toral Anosov diffeomorphisms have no Ruelle resonances in the open interval
$(1, e^{h_{\mathrm {top}}})$
.
Accurate electron beam phase-space theory for ionization-injection schemes driven by laser pulses
Authors: Tomassini Paolo , Massimo Francesco , Labate Luca , Gizzi Leonida A.
Published: December 2021

After the introduction of the ionization-injection scheme in laser wake field acceleration and of related high-quality electron beam generation methods, such as two-color and resonant multi-pulse ionization injection (ReMPI), the theory of thermal emittance has been used to predict the beam normalized emittance obtainable with those schemes. We recast and extend such a theory, including both higher order terms in the polynomial laser field expansion and non-polynomial corrections due to the onset of saturation effects on a single cycle. Also, a very accurate model for predicting the cycle-averaged distribution of the extracted electrons, including saturation and multi-process events, is proposed and tested. We show that our theory is very accurate for the selected processes of

${\mathrm{Kr}}^{8^{+}\to {10}^{+}}$

and

${\mathrm{Ar}}^{8^{+}\to {10}^{+}}$

, resulting in a maximum error below 1%, even in a deep-saturation regime. The accurate prediction of the beam phase-space can be implemented, for example, in laser-envelope or hybrid particle-in-cell (PIC)/fluid codes, to correctly mimic the cycle-averaged momentum distribution without the need for resolving the intra-cycle dynamics. We introduce further spatial averaging, obtaining expressions for the whole-beam emittance fitting with simulations in a saturated regime, too. Finally, a PIC simulation for a laser wakefield acceleration injector in the ReMPI configuration is discussed.
Investigation of the influence of miniature vortex generators on the large-scale motions of a turbulent boundary layer
Authors: Chan C.I. , Chin R.C.
Published: December 2021

Well resolved large-eddy simulation data are used to study the physical modulation effects of miniature vortex generators (MVGs) in a moderate Reynolds number zero pressure gradient turbulent boundary layer. Large-scale counter-rotating primary vortex pairs (PVPs) imposed by the MVG contribute to the formation of streamwise streaks by transporting high momentum fluids from the outer regions of the boundary layer towards the wall, giving rise to high-speed regions centred at the PVP. Consequently, low-speed regions are formed along the outer flank of the PVP, resulting in a pronounced alternating high- and low-speed flow pattern. The PVP also relates to regions with skin friction modification, where a local skin friction reduction of up to 15 % is obtained at the low-speed region, but the opposite situation is observed over the high-speed region. The MVG-induced flow feature is further investigated by spectral analysis of the triple decomposition velocity fluctuation. Pre-multiplied energy spectra of the streamwise MVG-induced velocity fluctuation reveal that the large-scale induced modes scale with the spanwise wavelength and the length of the MVG, but the energy peak is eventually repositioned to the size of the near-wall streaks in the streamwise direction. Analysis of the triple decomposition of the kinetic energy transport equations revealed the significance of the mean flow gradient in generating kinetic energy which sustains the secondary motion. There is also an energy transfer between the turbulent and MVG-induced kinetic energy independent of the mean flow.