bluuebunny/crossref_metadata_2025 huggingface dataset:
A ZnIIcomplex of ornidazole with decreased nitro radical anions that is still highly active onEntamoeba histolytica
Authors: Nandy Promita , Singha Soumen , Banyal Neha , Kumar Sanjay , Mukhopadhyay Kasturi , Das Saurabh
Published: June 2020

A monomeric complex of ZnIIwith ornidazole [Zn(Onz)2Cl2] decreases formation of the nitro-radical anion (R–NO2˙−), and this is realized by recording it in an enzyme assay using xanthine oxidase, which is a model nitro-reductase.
Boosting the efficiency of water oxidation via surface states on hematite photoanodes by incorporating Bi3+ ions
Authors: Khan Abdul Zeeshan , Kandiel Tarek A. , Abdel-Azeim Safwat , Alhooshani Khalid
Published: June 2020

The incorporation of Bi3+ ions into the hematite crystal structure induces the creation of oxygen vacancies and boosts the photoelectrochemical water oxidation kinetics.
Introduction to liquid composites
Authors: Bartlett Michael D. , Style Robert W.
Published: June 2020

Michael Bartlett and Robert Style introduce the Soft Matter themed collection on liquid composites.
The AMBRE Project: Spectrum normalisation influence on Mg abundances in the metal-rich Galactic disc
Authors: Santos-Peral P. , Recio-Blanco A. , de Laverny P. , Fernández-Alvar E. , Ordenovic C.
Published: June 2020

Context. The abundance of α-elements provides an important fossil signature in Galactic archaeology to trace the chemical evolution of the different disc populations. High-precision chemical abundances are crucial to improving our understanding of the chemodynamical properties present in the Galaxy. However, deriving precise abundance estimations in the metal-rich disc ([M/H] >  0 dex) is still challenging.

Aims. The aim of this paper is to analyse different error sources affecting magnesium abundance estimations from optical spectra of metal-rich stars.

Methods. We derived Mg abundances for 87522 high-resolution spectra of 2210 solar neighbourhood stars from the AMBRE Project, and selected the 1172 best parametrised stars with more than four repeated spectra. For this purpose, the GAUGUIN automated abundance estimation procedure was employed.

Results. The normalisation procedure has a strong impact on the derived abundances, with a clear dependence on the stellar type and the line intensity. For non-saturated lines, the optimal wavelength domain for the local continuum placement should be evaluated using a goodness-of-fit criterion, allowing mask-size dependence with the spectral type. Moreover, for strong saturated lines, applying a narrow normalisation window reduces the parameter-dependent biases of the abundance estimate, increasing the line-to-line abundance precision. In addition, working at large spectral resolutions always leads to better results than at lower ones. The resulting improvement in the abundance precision makes it possible to observe both a clear thin-thick disc chemical distinction and a decreasing trend in the magnesium abundance even at supersolar metallicities.

Conclusions. In the era of precise kinematical and dynamical data, optimising the normalisation procedures implemented for large spectroscopic stellar surveys would provide a significant improvement to our understanding of the chemodynamical patterns of Galactic populations.
Dust masses of young disks: constraining the initial solid reservoir for planet formation
Authors: Tychoniec Łukasz , Manara Carlo F. , Rosotti Giovanni P. , van Dishoeck Ewine F. , Cridland Alexander J. , Hsieh Tien-Hao , Murillo Nadia M. , Segura-Cox Dominique , van Terwisga Sierk E. , Tobin John J.
Published: June 2020

Context. Recent years have seen building evidence that planet formation starts early, in the first ~0.5 Myr. Studying the dust masses available in young disks enables us to understand the origin of planetary systems given that mature disks are lacking the solid material necessary to reproduce the observed exoplanetary systems, especially the massive ones.

Aims. We aim to determine if disks in the embedded stage of star formation contain enough dust to explain the solid content of the most massive exoplanets.

Methods. We use Atacama Large Millimeter/submillimeter Array (ALMA) Band 6 (1.1–1.3 mm) continuum observations of embedded disks in the Perseus star-forming region together with Very Large Array (VLA) Ka-band (9 mm) data to provide a robust estimate of dust disk masses from the flux densities measured in the image plane.

Results. We find a strong linear correlation between the ALMA and VLA fluxes, demonstrating that emission at both wavelengths is dominated by dust emission. For a subsample of optically thin sources, we find a median spectral index of 2.5 from which we derive the dust opacity index β = 0.5, suggesting significant dust growth. Comparison with ALMA surveys of Orion shows that the Class I dust disk mass distribution between the two regions is similar, but that the Class 0 disks are more massive in Perseus than those in Orion. Using the DIANA opacity model including large grains, with a dust opacity value of κ9 mm = 0.28 cm2 g−1, the median dust masses of the embedded disks in Perseus are 158 M⊕ for Class 0 and 52 M⊕ for Class I from the VLA fluxes. The lower limits on the median masses from ALMA fluxes are 47 M⊕ and 12 M⊕ for Class 0 and Class I, respectively, obtained using the maximum dust opacity value κ1.3 mm = 2.3 cm2 g−1. The dust masses of young Class 0 and I disks are larger by at least a factor of ten and three, respectively, compared with dust masses inferred for Class II disks in Lupus and other regions.

Conclusions. The dust masses of Class 0 and I disks in Perseus derived from the VLA data are high enough to produce the observed exoplanet systems with efficiencies acceptable by planet formation models: the solid content in observed giant exoplanets can be explained if planet formation starts in Class 0 phase with an efficiency of ~15%. A higher efficiency of ~30% is necessary if the planet formation is set to start in Class I disks.
Seeds of Life in Space (SOLIS)
Authors: Spezzano S. , Codella C. , Podio L. , Ceccarelli C. , Caselli P. , Neri R. , López-Sepulcre A.
Published: June 2020

Context. Contrary to what is expected from models of Galactic chemical evolution, the isotopic fractionation of silicon (Si) in the Galaxy has recently been found to be constant. This finding calls for new observations, also at core scales, to re-evaluate the fractionation of Si.

Aims. L1157-B1 is one of the outflow-shocked regions along the blue-shifted outflow that is driven by the Class 0 protostar L1157-mm. It is an ideal laboratory for studying the material ejected from the grains on very short timescales because its chemical composition is representative of the composition of the grains.

Methods. We imaged 28SiO, 29SiO, and 30SiO J = 2–1 emission towards L1157-B1 and B0 with the NOrthern Extended Millimeter Array (NOEMA) interferometer as part of the Seeds of Life in Space (SOLIS) large project. We present here a study of the isotopic fractionation of SiO towards L1157-B1. Furthermore, we used the high spectral resolution observations on the main isotopologue, 28SiO, to study the jet impact on the dense gas. We here also present single-dish observations obtained with the IRAM 30 m telescope and Herschel-HIFI. We carried out a non-local thermal equilibrium analysis using a large velocity gradient code to model the single-dish observations.

Results. From our observations we can show that (i) the 2–1 transition of the main isotopologue is optically thick in L1157-B1 even at high velocities, and (ii) the [29SiO/30SiO] ratio is constant across the source, and consistent with the solar value of 1.5.

Conclusions. We report the first isotopic fractionation maps of SiO in a shocked region and show the absence of a mass-dependent fractionation in 29Si and 30Si across L1157-B1. A high-velocity bullet in 28SiO has been identified, showing the signature of a jet impacting on the dense gas. With the dataset presented in this paper, both interferometric and single-dish, we were able to study the gas that is shocked at the B1a position and its surrounding gas in great detail.
Nanoindentation studies and analysis of the mechanical properties of Ti-Nb2O5 based composites
Authors: Alaneme Kenneth Kanayo , Fatokun Ayoyemi Adebanji , Oke Samuel Ranti , Olubambi Peter Apata
Published: June 2020

In this study, nanoindentation tests were used to evaluate the mechanical properties of spark plasma sintered Ti based composites containing 5, 10 and 15 wt.% Nb2O5, targeted for potential use as biomedical material. Nanoindentation tests were performed on the samples using indenter loads of 20 and 100 mN, while the microstructures were characterized using scanning electron microscopy. It was noted that with increasing Nb2O5 wt.%, there is transition from the lamellar structure of pure Ti to fully bimodal structures for the Ti-10 wt.% Nb2O5 and Ti-15 wt.% Nb2O5 composites. The hardness (6.0–40.67 GPa (20 mN) and 2.4–12.03 GPa (100 mN)) and reduced elastic modulus (115–266.91 GPa (20 mN) and (28.05–96.873 GPa (100 mN)) of the composites increases with increase in the Nb2O5 content, attributed to contributions of load transfer from the Ti matrix to the relatively harder Nb2O5 particles, particle and dispersion strengthening mechanisms. The elastic recovery index also improved with increase in Nb2O5 content, while the inverse was noted with respect to plasticity index. The elastic strain to failure and yield pressure both improved with increase in Nb2O5 content, which suggests that the antiwear properties and resistance to impact loading equally improves with Nb2O5 addition.
Befestigungsmöglichkeiten von Brackets und Attachments in der
Kieferorthopädie
Authors: Jungbauer Rebecca , Liebermann Anja , Kieschnick Annett , Stawarczyk Bogna
Published: June 2020

Sowohl für die Befestigung von Brackets als auch von
Aligner-Attachments stehen verschiedene Materialien und Strategien zur
Auswahl. Die Vorbereitung der Schmelz-Oberfläche für die
adhäsive Befestigung kann mit Phosphorsäure im Etch and
Rinse-Verfahren oder mittels diverser selbstätzender
Adhäsive vorgenommen werden. Die Materialien zur Befestigung
unterscheiden sich hinsichtlich der Monomermatrix, der
Füllkörper und deren Anteile sowie ihres Initiatiorsystems.
Brackets können direkt oder indirekt adhäsiv befestigt
werden. Attachments für die Behandlung mit Alignern können
ein- oder zweiphasig auf die entsprechenden Zähne aufgebracht
werden. Ziel dieses Artikels ist es, anhand der aktuellen Literatur einen
Überblick über die verschiedenen Materialien und
Befestigungsstrategien zu geben.
Sehr verehrte Kolleginnen, sehr geehrte Kollegen, liebe Mitglieder der DGPM,
Authors: Schlößer Rolf
Published: June 2020

ein Virus hat die Welt in den Griff bekommen und das alltägliche Leben der
Menschen in allen Länder und Kontinenten grundlegend verändert.
Kongresse und Tagungen fielen aus; das „Social Distancing“
führte auch wirklich zu sozialen Verlusten für viele Menschen und
wir hoffen, dass sie wieder heilen können.
Full-Thickness Skin Grafts and Quilting Sutures for the Reconstruction of Internal Nasal Lining
Authors: Gostian PD Dr. med. Antoniu-Oreste , Balk Dr. med. Matthias , Stegmann Dr. med. Achim , Iro Prof. Dr. med. Dr. h.c. Heinrich , Wurm Prof. Dr. med. Jochen
Published: June 2020

Restoration of the inner nasal lining is an essential factor in successful nasal reconstruction. Among various methods, free full-thickness skin grafting represents a readily available and feasible technique. A prerequisite for success is a secure and immobile fixation to the undersurface of the nourishing forehead flap. This retrospective study aims to evaluate the results of multiple quilting sutures to secure free full-thickness skin grafts for the reconstruction of the inner nasal lining in partial and extended nasal reconstruction. Between February 1, 2015, and December 31 2018, 16 patients underwent three-stage nasal reconstruction of all three layers using a forehead flap. All full-thickness free flaps were harvested from either the neck or inguinal area and fixated to the undersurface of the distal part of the forehead flap by multiple quilting sutures. All but one free skin grafts healed well (seven ♀; mean: 63 years; range: 52–81). Four patients developed minor complications that resolved completely through conservative treatment. One patient with a history of stroke, extensive nicotine abuse, and arterial hypertension developed flap necrosis that required two surgical revisions and ended up with a stenosis of the left nostril. The follow-up time averaged 18.4 months (range: 3–55 months). Multiple quilting sutures are an effective and feasible option to fixate full-thickness free skin grafts on the undersurface of the forehead flap for the reconstruction of the inner nasal lining. They are not associated with increased risks for necrosis and can be applied even to extended full-thickness nasal defects in selected cases.
Humanities, criticality and transparency: global health histories and the foundations of inter-sectoral partnerships for the democratisation of knowledge
Authors: Bhattacharya Sanjoy , Medcalf Alexander , Ahmed Aliko
Published: June 2020

Historians of medicine have been influential actors in a broader movement to highlight the social, institutional and administrative benefits of historical research, and its relevance for national and international policy intended to extend and improve contemporary healthcare. Historical perspectives are fundamentally useful to health policy actors because questions about what it is to be healthy, to suffer disease or disability, and the presentation and acceptance of solutions are interwoven in culturally and historically complex webs of meaning. Historians, as they have examined the social and cultural social determinants of health, have also used their work as public engagement, educational and policy resource tools, demonstrating that history is an effective way of making key issues in science, medicine and well-being more administratively responsive and accessible to lay audiences. This article explores such issues through the case study of the long-running World Health Organization (WHO) Global Health Histories project. Established in late 2004, the project’s enduring rationale has been that understanding the history of health helps the global public health community to respond to the challenges of today and help shape a healthier future. It has sought to do this by bringing together researchers and policy-makers into honest and democratic conversations and exchanges of ideas. The aim has been to stimulate a fusion between historical evidence and current policy approaches to many of the most urgent health issues. This article discusses the challenges and opportunities in bringing health history and policy together, and explores the importance of explaining historical method and the need to convince policy partners how history is evidence-based, that it can access and provide useful strategic information from archives of major institutions, and, therefore, a useful contributor to making policy initiatives adaptable and acceptable within complex polities and societies.
Situated data analysis: a new method for analysing encoded power relationships in social media platforms and apps
Authors: Rettberg Jill Walker
Published: June 2020

This paper proposes situated data analysis as a new method for analysing social media platforms and digital apps. An analysis of the fitness tracking app Strava is used as a case study to develop and illustrate the method. Building upon Haraway’s concept of situated knowledge and recent research on algorithmic bias, situated data analysis allows researchers to analyse how data is constructed, framed and processed for different audiences and purposes. Situated data analysis recognises that data is always partial and situated, and it gives scholars tools to analyse how it is situated, and what effects this may have. Situated data analysis examines representations of data, like data visualisations, which are meant for humans, and operations with data, which occur when personal or aggregate data is processed algorithmically by machines, for instance to predict behaviour patterns, adjust services or recommend content. The continuum between representational and operational uses of data is connected to different power relationships between platforms, users and society, ranging from normative disciplinary power and technologies of the self to environmental power, a concept that has begun to be developed in analyses of digital media as a power that is embedded in the environment, making certain actions easier or more difficult, and thus remaining external to the subject, in contrast to disciplinary power which is internalised. Situated data analysis can be applied to the aggregation, representation and operationalization of personal data in social media platforms like Facebook or YouTube, or by companies like Google or Amazon, and gives researchers more nuanced tools for analysing power relationships between companies, platforms and users.
The Rosetta Stone and the Nemrud Nomos: the discovery of significant textual and astronomical similarities
Authors: Crijns Maurice
Published: June 2020

Commagene was an independent and wealthy kingdom in the east of present Turkey from ca. 160 to 20 BCE. A text referred to as Nomos (Dörner) describes the astro-religion of Commagene (Crijns). The text on the Egyptian Rosetta Stone describes the Ptolemaic astro-religion (Rosetta Stone Online Project). It is shown here that the Rosetta text is a precursor of the Nomos, based on textual and astronomical evidence. The coronation dates as mentioned in both texts display a similar configuration in the sky as substantiated by the configuration on the Lion Horoscope at the top of Mt. Nemrud. Not only the date can be calculated, but also the precise time. The time is determined by an annual phenomenon of the marker star Sirius and Regulus, respectively. The latter has been overseen by scholars and underlines the importance of having at least a basic understanding of archaeoastronomy. These unnoticed similarities indicate that the astro-religions of the Middle East are not stand alone cults. The significant similarities point at a shared heritage i.e., a star cult dating maybe as far back as the era of the Fertile Crescent at the dawn of mankind.
Gender gaps in urban mobility
Authors: Gauvin Laetitia , Tizzoni Michele , Piaggesi Simone , Young Andrew , Adler Natalia , Verhulst Stefaan , Ferres Leo , Cattuto Ciro
Published: June 2020

Mobile phone data have been extensively used to study urban mobility. However, studies based on gender-disaggregated large-scale data are still lacking, limiting our understanding of gendered aspects of urban mobility and our ability to design policies for gender equality. Here we study urban mobility from a gendered perspective, combining commercial and open datasets for the city of Santiago, Chile. We analyze call detail records for a large cohort of anonymized mobile phone users and reveal a gender gap in mobility: women visit fewer unique locations than men, and distribute their time less equally among such locations. Mapping this mobility gap over administrative divisions, we observe that a wider gap is associated with lower income and lack of public and private transportation options. Our results uncover a complex interplay between gendered mobility patterns, socio-economic factors and urban affordances, calling for further research and providing insights for policymakers and urban planners.
“Indiscipline” in context: a political-economic grounding for dangerous driving behaviors among Tro-Tro drivers in Ghana
Authors: Boateng Festival Godwin
Published: June 2020

This paper attempts a better explanation for the causes of dangerous driving behaviors among “Tro-Tro”(minibus) drivers in Ghana. The current media, policy, and academic coverage of the problem reveals an immutable discourse that considers the behaviors (such as over speeding) as a function of moral failure, indiscipline, or bad attitudes on the part of the drivers. Often little consideration is given to the context of the behaviors and their influences. This paper provides an alternative explanation that considers the behaviors as predictable actions that are systematically connected to the Tro-Tro industry. Tro-Tro drivers operate within a precarious work climate marked by problems such as low wages; cut-throat competition; high level of job insecurity; imposition of non-negotiable throat-cutting daily fees by car owners and harassments from bribe-demanding corrupt police officers. The exigencies of meeting these numerous financial and other demands of their work,not moral failure, are what fuel dangerous driving behaviors among the drivers. Based on this analysis, the present public policy of using penal populism (i.e., heavy fines and prison sentences) to address road trauma in Ghana is ineffective for inducing safer driving behaviors among Tro-Tro drivers. Interventions to reduce road transport problems involving such commercial passenger vehicles in Ghana and other developing countries similarly situated must be broad, more-wider reaching and include initiatives that also address the range of political-economic causes, motivations, and constraints that incentivize the drivers to drive dangerously. The paper contributes to the sustainable development goals of ensuring safe and sustainable transport (SDG 11.2), and reducing deaths and injuries from road accidents (SDG 3.6).
Knowing qualia: reloading the displaced perception model
Authors: de Sá Pereira Roberto Horácio
Published: June 2020

How does one know the phenomenal character of one’s own experience? I aim to present and defend a new view of the epistemology of qualia that addresses this issue. My view results from a reworking of Dretske’s displaced perception model. The guiding line is the key Wittgensteinian insight of his Private Language Argument, namely the claim that no inner perception of qualia can justify our corresponding qualia-beliefs. My reworking of the original model starts with the rejection of Dretske’s representationalism, as well as any other metaphysical views about the ultimate nature of qualia. The reworking of the displaced perception model I am proposing is supposed to be compatible with any available metaphysical view on qualia. The second step consists of rejecting the epistemological misgivings of the original model, namely the view that knowing qualia requires “connecting beliefs” along with “meta-representations.” Yet, Dretske’s crucial mistake has been to force knowledge of qualia into the “belief-box.” As a matter of fact, there is only one belief involved in introspecting qualia, namely the qualia-belief itself. The third final step is this. Assuming the key Wittgensteinian insight, I argue that introspection of qualia is a process that is both epistemically reliable and automatic. It is reliable because it dispenses with justification of any beliefs whatsoever. Moreover, it is automatic because it also dispenses with reflexive connecting beliefs. For example, it takes nonconceptual awareness of the color blue as an input and automatically yields the belief that phenomenal blue is the conscious character of my experience of the sky as an output just by employing the concept BLUE.
Change of a Weibel-type to an Alfvénic shock in pair plasma by upstream waves
Authors: Dieckmann M. E. , Riordan J. D. , Pe'er A.
Published: June 2020

We examine with particle-in-cell simulations how a parallel shock in pair plasma reacts to upstream waves, which are driven by escaping downstream particles. Initially, the shock is sustained in the two-dimensional simulation by a magnetic filamentation (beam-Weibel) instability. Escaping particles drive an electrostatic beam instability upstream. Modifications of the upstream plasma by these waves hardly affect the shock. In time, a decreasing density and an increasing temperature of the escaping particles quench the beam instability. A larger thermal energy along than perpendicular to the magnetic field destabilizes the pair-Alfvén mode. In the rest frame of the upstream plasma, the group velocity of the growing pair-Alfvén waves is below that of the shock and the latter catches up with the waves. Accumulating pair-Alfvén waves gradually change the shock in the two-dimensional simulation from a Weibel-type shock into an Alfvénic shock with a Mach number that is about 6 for our initial conditions.
Complex system approach to investigate and mitigate thermoacoustic instability in turbulent combustors
Authors: Sujith R. I. , Unni Vishnu R.
Published: June 2020

Thermoacoustic instability in turbulent combustors is a nonlinear phenomenon resulting from the interaction between acoustics, hydrodynamics, and the unsteady flame. Over the years, there have been many attempts toward understanding, prognosis, and mitigation of thermoacoustic instabilities. Traditionally, a linear framework has been used to study thermoacoustic instability. In recent times, researchers have been focusing on the nonlinear dynamics related to the onset of thermoacoustic instability. In this context, the thermoacoustic system in a turbulent combustor is viewed as a complex system, and the dynamics exhibited by the system is perceived as emergent behaviors of this complex system. In this paper, we discuss these recent developments and their contributions toward the understanding of this complex phenomenon. Furthermore, we discuss various prognosis and mitigation strategies for thermoacoustic instability based on complex system theory.
Magnetic characteristics of epitaxial NiO films studied by Raman spectroscopy
Authors: Feldl J. , Budde M. , Tschammer C. , Bierwagen O. , Ramsteiner M.
Published: June 2020

Raman spectroscopy is utilized to study the magnetic characteristics of heteroepitaxial NiO thin films grown by plasma-assisted molecular beam epitaxy on MgO(100) substrates. For the determination of the Néel temperature, we demonstrate a reliable approach by analyzing the temperature dependence of the Raman peak originating from second-order scattering by magnons. The antiferromagnetic coupling strength is found to be strongly influenced by the growth conditions. The low-temperature magnon frequency and the Néel temperature are demonstrated to depend on the biaxial lattice strain and the degree of structural disorder, which is dominated by point defects.
Reduced scaling extended multi-state CASPT2 (XMS-CASPT2) using supporting subspaces and tensor hyper-contraction
Authors: Song Chenchen , Martínez Todd J.
Published: June 2020

We present a reduced scaling formulation of the extended multi-state CASPT2 (XMS-CASPT2) method, which is based on our recently developed state-specific CASPT2 (SS-CASPT2) formulation using supporting subspaces and tensor hyper-contraction. By using these two techniques, the off-diagonal elements of the effective Hamiltonian can be computed with only O(N3) operations and O(N2) memory, where N is the number of basis functions. This limits the overall computational scaling to O(N4) operations and O(N2) memory. Thus, excited states can now be obtained at the same reduced (relative to previous algorithms) scaling we achieved for SS-CASPT2. In addition, we also investigate how the energy denominators can be factorized with the Laplace quadrature when some of the denominators are negative, which is critical for excited state calculations. An efficient implementation of the method has been developed using graphical processing units while also exploiting spatial sparsity in tensor operations. We benchmark the accuracy of the new method by comparison to non-THC formulated XMS-CASPT2 for the excited states of various molecules. In our tests, the THC approximation introduces negligible errors (≈0.01 eV) compared to the non-THC reference method. Scaling behavior and computational timings are presented to demonstrate performance. The new method is also interfaced with quantum mechanics/molecular mechanics (QM/MM). In an example study of green fluorescent protein, we show how the XMS-CASPT2 potential energy surfaces and excitation energies are affected by increasing the size of the QM region up to 278 QM atoms with more than 2300 basis functions.
Radially symmetric solutions for Navier–Stokes–Smoluchowski system: Global existence in unbounded annular domain and center singularity
Authors: Zhu Limei , Huang Bingyuan , Huang Jinrui
Published: June 2020

In this paper, we establish the global existence of radially symmetric strong solutions of a fluid–particle interaction system in an unbounded annular domain. Furthermore, the description for possible breakdown of regularity for the 3D problem is studied: the concentration of mass on the center.
Effective diffusivity of Brownian particles in a two dimensional square lattice of hard disks
Authors: Mangeat M. , Guérin T. , Dean D. S.
Published: June 2020

We revisit the classic problem of the effective diffusion constant of a Brownian particle in a square lattice of reflecting impenetrable hard disks. This diffusion constant is also related to the effective conductivity of non-conducting and infinitely conductive disks in the same geometry. We show how a recently derived Green’s function for the periodic lattice can be exploited to derive a series expansion of the diffusion constant in terms of the disk’s volume fraction φ. Second, we propose a variant of the Fick–Jacobs approximation to study the large volume fraction limit. This combination of analytical results is shown to describe the behavior of the diffusion constant for all volume fractions.
Reinvestigation of the Rydberg W1Π(ν = 1) level of 12C16O, 13C16O, and 12C18O through rotationally dependent photodissociation branching ratio measurements
Authors: Jiang Pan , Chi Xiaoping , Zhang Guodong , Yin Tonghui , Guan Lichang , Cheng Min , Gao Hong
Published: June 2020

A recent high resolution photoabsorption study revealed that the Rydberg W1Π(ν = 1) level of carbon monoxide (CO) is perturbed by the valence E″1Π(ν = 0) level, and the predissociation linewidth shows drastic variation at the crossing point due to the interference effect [Heays et al., J. Chem. Phys. 141(14), 144311 (2014)]. Here, we reinvestigate the Rydberg W1Π(ν = 1) level for the three CO isotopologues, 12C16O, 13C16O, and 12C18O, by measuring the rotationally dependent photodissociation branching ratios. The C+ ion photofragment spectra obtained here reproduce the recent high resolution photoabsorption spectra very well, including the presence of the valence E″1Π(ν = 0) level. The photodissociation branching ratios into the spin-forbidden channel C(1D) + O(3P) show sudden increases at the crossing point between the W1Π(ν = 1) and E″1Π(ν = 0) levels, which is in perfect accordance with the drastic variation of the linewidth observed in the recent spectroscopic study. Further analysis reveals that the partial predissociation rate into the lowest channel C(3P) + O(3P) shows a much more prominent decrease at the crossing point, which is caused by the interference effect between the W1Π(ν = 1) and E″1Π(ν = 0) levels, than that into the spin-forbidden channel C(1D) + O(3P), and this is the reason of the sudden increase as observed in the photodissociation branching ratio measurements. We hope that the current experimental investigation will stimulate further theoretical studies, which could thoroughly address all the experimental observations in a quantitative way.
Diffusion with resetting in a logarithmic potential
Authors: Ray Somrita , Reuveni Shlomi
Published: June 2020

We study the effect of resetting on diffusion in a logarithmic potential. In this model, a particle diffusing in a potential U(x) = U0 log |x| is reset, i.e., taken back to its initial position, with a constant rate r. We show that this analytically tractable model system exhibits a series of transitions as a function of a single parameter, βU0, the ratio of the strength of the potential to the thermal energy. For βU0 < −1, the potential is strongly repulsive, preventing the particle from reaching the origin. Resetting then generates a non-equilibrium steady state, which is exactly characterized and thoroughly analyzed. In contrast, for βU0 > −1, the potential is either weakly repulsive or attractive, and the diffusing particle eventually reaches the origin. In this case, we provide a closed-form expression for the subsequent first-passage time distribution and show that a resetting transition occurs at βU0 = 5. Namely, we find that resetting can expedite arrival to the origin when −1 < βU0 < 5, but not when βU0 > 5. The results presented herein generalize the results for simple diffusion with resetting—a widely applicable model that is obtained from ours by setting U0 = 0. Extending to general potential strengths, our work opens the door to theoretical and experimental investigation of a plethora of problems that bring together resetting and diffusion in logarithmic potential.
Deep UV-assisted capacitance–voltage characterization of post-deposition annealed Al2O3/
β
-Ga2O3 (001) MOSCAPs
Authors: Jian Zhe (Ashley) , Mohanty Subhajit , Ahmadi Elaheh
Published: June 2020

In this Letter, the interface state density (Dit) and bulk trap density (nbulk) in post-deposition annealed Al2O3/β-Ga2O3 (001) metal–oxide–semiconductor capacitors (MOSCAPs) are extracted using the deep UV-assisted capacitance–voltage method and an improved physical analytical model. The effects of atomic layer deposition (ALD) temperature and post-deposition annealing (PDA) conditions are also studied. Increasing the deposition temperature and PDA at 500 °C in O2 seems to be an effective way to improve the forward breakdown voltage (BV) and suppress capacitance–voltage hysteresis in Al2O3/β-Ga2O3 (001) MOSCAPs. These results are useful for future high performance Ga2O3-based metal-oxide-semiconductor field effect transistors (MOSFETs) and Fin-FETs.
Wave-canceling acoustic metarod architected with single material building blocks
Authors: Ogasawara Akira , Fujita Kentaro , Tomoda Motonobu , Matsuda Osamu , Wright Oliver B.
Published: June 2020

Preventing elastic waves from traveling down thin structures is a subject of great interest from the point of view of both physics and applications. It represents a problem—mirrored by the case of light in waveguides—that has broad implications. To completely prohibit sound waves in a given frequency range in rods, for example, all axially propagating acoustic eigenmodes must exhibit strong damping. Here, we demonstrate experimentally and by simulation a metamaterial rod made from a single material that can simultaneously shut out all elastic-wave polarizations, namely longitudinal, flexural, and torsional modes, in a band in the sub-kHz range. We first bond five acrylic building blocks together to make a subwavelength resonator and then fix an array of these inside an acrylic tube to form a cylindrical metarod that inhibits sound transmission in the metamaterial bandgap frequency range. Applications include vibration control and earthquake mitigation.
Derivation of the Derjaguin approximation for the case of inhomogeneous solvents
Authors: Wennerström Håkan , Stenhammar Joakim
Published: June 2020

The Derjaguin approximation (DA) relates the force between curved surfaces to the interaction free energy between parallel planes. It is typically derived by considering the direct interaction between the bodies involved, thus treating the effect of an intervening solvent implicitly by a rescaling of the corresponding Hamaker constant. Here, we provide a generalization of DA to the case of a molecular medium between the bodies, as is the case in most applications. The derivation is based on an explicit statistical–mechanical treatment of the contribution to the interaction force from a molecular solvent using a general expression for intermolecular and molecule–surface interactions. Starting from an exact expression for the force, DA is arrived at by a series of well-defined approximations. Our results show that DA remains valid in a molecular solvent as long as (i) the surface–molecule interactions are of a much shorter range than the radius R of the sphere and (ii) the density correlation length in the solvent is smaller than R. We then extend our analysis to the case where a phase transition occurs between the surfaces, which cannot easily be covered using a statistical–mechanical formalism due to the discontinuous change in the density of the medium. Instead, using a continuum thermodynamic description, we show that this phase transformation induces an attractive force between the bodies and that the force between curved surfaces can be related to the free energy in the corresponding planar case, in accordance with DA.
Development of closure relations for the motion of Taylor bubbles in vertical and inclined annular pipes using high-fidelity numerical modeling
Authors: Mitchell T. , Leonardi C.
Published: June 2020

This study analyses the flow of Taylor bubbles through vertical and inclined annular pipes using high-fidelity numerical modeling. A recently developed phase-field lattice Boltzmann method is employed for the investigation. This approach resolves the two-phase flow behavior by coupling the conservative Allen–Cahn equation to the Navier–Stokes hydrodynamics. This paper makes contributions in three fundamental areas relating to the flow of Taylor bubbles. First, the model is used to determine the relationship between the dimensionless parameters (Eötvös and Morton numbers) and the bubble rise velocity (Froude number). There currently exists no surrogate model for the rise of a Taylor bubble in an annular pipe that accounts for fluid properties. Instead, relations generally include the diameter of the outer and inner pipes only. This study covered Eötvös numbers between 10 and 700 and Morton numbers between 10−6 and 100. As such, the proposed correlation is applicable to concentric annular pipes within this range of parameters. An assessment of the correlation to parameters outside of this range was made; however, this was not the primary scope for the investigation. Following this, the effect of pipe inclination was introduced with the impact on rise velocity measured. A correlation between the inclination angle and the rise velocity was proposed and its performance quantified against the limited experimental data available. Finally, the high-fidelity numerical results were analyzed to provide key insights into the physical mechanisms associated with annular Taylor bubbles and the shape they form. To extend this work, future studies on the effect of pipe eccentricity, diameter ratios, and pipe fittings (e.g., elbows and risers) on the flow of Taylor bubbles will be conducted.
Effects of magnetization relaxation in ferrofluid film flows under a uniform magnetic field
Authors: Yang Wenming , Liu Beiying
Published: June 2020

We analyze the magnetization relaxation effects of a ferrofluid film flow governed by the ferrohydrodynamics encompassing the Fokker–Planck magnetization equation in a Couette–Poiseuille configuration subject to an applied uniform stationary magnetic field perpendicular to the boundaries. A solver based on OpenFOAM is programmed to find solutions numerically for the velocity, spin velocity, and magnetization in ferrofluid films under the combined pressure gradient, boundary flow, and magnetic field forcing. The solver is validated by comparison with the classical Couette–Poiseuille flows and the analytic solutions of the magnetization relaxation problem when the product of flow vorticity and relaxation time is much smaller than unit, ΩτB≪1. We compare the effects of magnetization relaxation obtained from the phenomenological magnetization equation with those from the equation derived microscopically. The results obtained from the former equation are not suitable for the description of ferrofluid film flows. Due to the magnetization relaxation effects, a misalignment between the local magnetization and the local magnetic field is observed. The net effects are that the flow is hampered by magnetic fields and it manifests as diminished slopes of vorticity profiles and reduced volumetric flow rates. The magnetization relaxation effects also slow down the spin velocity of particles or change their direction, which leads to an enhanced effective viscosity. The total tangential stress exerted on the moving boundary is higher than that of the classical Couette–Poiseuille flow owing to the addition of a magnetic stress. The magnetization relaxation effect is more significant in cases of ferrofluids with higher relaxation times.
Phononic canonical quasicrystalline waveguides
Authors: Gei M. , Chen Z. , Bosi F. , Morini L.
Published: June 2020

The dynamic behavior of the class of periodic waveguides whose unit cells are generated through a quasicrystalline sequence can be interpreted geometrically in terms of a trace map that embodies the recursive rule obeyed by traces of the transmission matrices. We introduce the concept of canonical quasicrystalline waveguides, for which the orbits predicted by the trace map at specific frequencies, called canonical frequencies, are periodic. In particular, there exist three families of canonical waveguides. The theory reveals that for those (i) the frequency spectra are periodic and the periodicity depends on the canonical frequencies, (ii) a set of multiple periodic orbits exists at frequencies that differ from the canonical ones, and (iii) perturbation of the periodic orbit and linearization of the trace map define a scaling parameter, linked to the golden ratio, which governs the self-similar structure of the spectra. The periodicity of the waveguide responses is experimentally verified on finite specimens composed of selected canonical unit cells.
On the integral characteristic function of the Sturm-Liouville problem
Authors: Valovik D. V.
Published: June 2020

We introduce a function whose zeros, and only these zeros, are eigenvalues of the corresponding Sturm-Liouville problem. The boundary conditions of the problem depend continuously on the spectral parameter. Therefore, it makes sense to call the function thus constructed a characteristic function of the Sturm-Liouville problem (however, it is not a characteristic function in the ordinary sense). An investigation of the function thus obtained enables us to prove the solvability of the problem in question, to find the asymptotic behaviour of the eigenvalues, to obtain comparison theorems, and to introduce an indexing of the eigenvalues and the zeros of eigenfunctions in a natural way.

Bibliography: 31 titles.
Sodium deficiency in lucerne (
Authors: Champness M. R. , McCormick J. I. , Bhanugopan M. S. , McGrath S. R.
Published: June 2020

Context Liveweight gains (LWGs) of lambs grazing lucerne (Medicago sativa L.) in the mixed-farming zone of Australia commonly do not match predicted rates of growth. It has been suggested that this could be due to sodium (Na) deficiency or an imbalance in the crude protein : metabolisable energy ratio (CP : ME). Aims This research aimed to determine whether sodium concentration in lucerne is below requirements for growing lambs and whether supplementation with salt (NaCl) and/or barley grain would increase LWG of lambs grazing lucerne. Methods Pluck-samples were collected along a transect in 65 paddocks containing lucerne pasture in southern Australia. Herbage that most likely represented the animal diet was ‘plucked’, avoiding the less digestible plant parts. Two replicated grazing experiments using different cohorts of lambs compared LWG of unsupplemented lambs with lambs given supplements of salt and/or barley. Key results The survey of lucerne pastures found that Na concentrations were below published requirements (0.07 g Na/kg DM) for growing lambs in 85% of samples collected from dryland lucerne pastures, but were above lamb requirements in 95% of samples collected from lucerne pastures gown under spray irrigation, which suggests a degree of salinity in the irrigation water. Supplementation with salt or barley did not affect LWG of lambs in Experiment 1, and residual feed on-offer did not differ among treatments. Salt increased LWG by 14% in Experiment 2 (292 g/lamb.day vs 256 g/lamb.day in those without access to salt; P = 0.03), with a return on investment of 1220%. Supplementation with whole barley did not increase (P > 0.05) LWG of lambs grazing lucerne. Barley supplementation resulted in higher residual feed on-offer in Experiment 2, suggesting a substitution of barley for lucerne. Mean LWG in Experiment 1 (192 g/lamb.day) was lower than in Experiment 2 (274 g/lamb.day), suggesting that the lack of response to salt supplementation in Experiment 1 may have been due to lamb growth rates being restricted by other factors such as reduced leaf availability and diet quality. Conclusions and implications Results of the survey and grazing experiments confirm that Na concentration of dryland lucerne in southern Australia is commonly below lamb requirements. Producers should consider Na supplementation for lambs grazing dryland lucerne pastures as a way to increase lamb growth rates.
The stem cell marker
Prom1
promotes axon regeneration by down-regulating cholesterol synthesis via Smad signaling
Authors: Lee Jinyoung , Shin Jung Eun , Lee Bohm , Kim Hyemin , Jeon Yewon , Ahn Seung Hyun , Chi Sung Wook , Cho Yongcheol
Published: June 2020

Significance

This work presents a concept for promoting the neuronal regenerative potential by engineering the expression of a stem cell marker,
Prom1
. We identify
Prom1
as a developmentally down-regulated neuronal intrinsic factor of axon regeneration. Replenishing
Prom1
expression amplifies the axonal regenerative potential by transcriptionally inhibiting cholesterol metabolism via Smad-dependent signaling. We provide evidence that a reduction in cholesterol synthesis empowers neuronal regrowth capacity. This work suggests that Food and Drug Administration-approved cholesterol-lowering drugs are potential candidates for neuroregenerative medicine.
Uncoupling DNA damage from chromatin damage to detoxify doxorubicin
Authors: Qiao Xiaohang , van der Zanden Sabina Y. , Wander Dennis P. A. , Borràs Daniel M. , Song Ji-Ying , Li Xiaoyang , van Duikeren Suzanne , van Gils Noortje , Rutten Arjo , van Herwaarden Tessa , van Tellingen Olaf , Giacomelli Elisa , Bellin Milena , Orlova Valeria , Tertoolen Leon G. J. , Gerhardt Sophie , Akkermans Jimmy J. , Bakker Jeroen M. , Zuur Charlotte L. , Pang Baoxu , Smits Anke M. , Mummery Christine L. , Smit Linda , Arens Ramon , Li Junmin , Overkleeft Hermen S. , Neefjes Jacques
Published: June 2020

Significance

Anthracyclines like doxorubicin are anticancer drugs, used by over 1 million cancer patients annually. However, they cause severe side effects, most notably, cardiotoxicity and therapy-related malignancies. It is unclear whether these side effects are directly linked to their anticancer activity. Doxorubicin exerts two activities: DNA damage and chromatin damage. Here, we show that both activities conspire in the cardiotoxicity, while doxorubicin variants with only chromatin-damaging activity remain active anticancer drugs devoid of side effects. This challenges the concept that doxorubicin works primarily by inducing DNA double-strand breaks and reveals another major anticancer activity, chromatin damage. Translating these observations will yield anticancer drugs for patients that are currently excluded from doxorubicin treatment and improve the quality of life of cancer survivors.
Whose line is it anyway?
Authors: Cedar Talli
Published: June 2020

The goal of this contribution is to distinguish between the implied-author and
other narrative voices in order to answer the question of how the implied-author
conveys criticism. For this purpose, I introduce three pragmatic cues. I argue that
these serve as a mechanism connecting text and context, allowing the implied-author
to convey ironic/humoristic criticism. I found the combination of footing and
narrative entities a useful methodology. I offer an analysis of Jerome K. Jerome’s
novel Three Men in a Boat using these cues. This
theoretical-methodological combination enabled me to distinguish between the
speaker-meanings of the implied-author and the narrator in this novel; describe the
three-way relations between the implied-author/implied-reader/narrator; and expose
the implied-author’s critical stance towards its narrator.