bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct measurements of atomic oxygen in the mesosphere and lower thermosphere using terahertz heterodyne spectroscopy
Authors: Richter Heiko , Buchbender Christof , Güsten Rolf , Higgins Ronan , Klein Bernd , Stutzki Jürgen , Wiesemeyer Helmut , Hübers Heinz-Wilhelm 
Published: January 2021

AbstractAtomic oxygen is a main component of the mesosphere and lower thermosphere of the Earth, where it governs photochemistry and energy balance and is a tracer for dynamical motions. However, its concentration is extremely difficult to measure with remote sensing techniques since atomic oxygen has few optically active transitions. Current indirect methods involve photochemical models and the results are not always in agreement, particularly when obtained with different instruments. Here we present direct measurements—independent of photochemical models—of the ground state 3P1 → 3P2 fine-structure transition of atomic oxygen at 4.7448 THz using the German Receiver for Astronomy at Terahertz Frequencies (GREAT) on board the Stratospheric Observatory for Infrared Astronomy (SOFIA). We find that our measurements of the concentration of atomic oxygen agree well with atmospheric models informed by satellite observations. We suggest that this direct observation method may be more accurate than existing indirect methods that rely on photochemical models.
Type Ic supernovae from the (intermediate) Palomar Transient Factory
Authors: Barbarino C. , Sollerman J. , Taddia F. , Fremling C. , Karamehmetoglu E. , Arcavi I. , Gal-Yam A. , Laher R. , Schulze S. , Wozniak P. , Yan Lin 
Published: January 2021

Context.Type Ic supernovae represent the explosions of the most stripped massive stars, but their progenitors and explosion mechanisms remain unclear. Larger samples of observed supernovae can help characterize the population of these transients.Aims.We present an analysis of 44 spectroscopically normal Type Ic supernovae, with focus on the light curves. The photometric data were obtained over 7 years with the Palomar Transient Factory and its continuation, the intermediate Palomar Transient Factory. This is the first homogeneous and large sample of SNe Ic from an untargeted survey, and we aim to estimate explosion parameters for the sample.Methods.We present K-correctedBgrizlight curves of these SNe, obtained through photometry on template-subtracted images. We performed an analysis on the shape of ther-band light curves and confirmed the correlation between the rise parameter Δm−10and the decline parameter Δm15. Peakr-band absolute magnitudes have an average of −17.71 ± 0.85 mag. To derive the explosion epochs, we fit ther-band lightcurves to a template derived from a well-sampled light curve. We computed the bolometric light curves usingrandgband data,g − rcolors and bolometric corrections. Bolometric light curves and Fe IIλ5169 velocities at peak were used to fit to the Arnett semianalytic model in order to estimate the ejecta massMej, the explosion energyEKand the mass of radioactive nickelM(56Ni) for each SN.Results.Including 41 SNe, we find average values of ⟨Mej⟩ = 4.50 ± 0.79 M⊙, ⟨EK⟩ = 1.79 ± 0.29 × 1051erg, and ⟨M56Ni⟩ = 0.19 ± 0.03 M⊙. The explosion-parameter distributions are comparable to those available in the literature, but our large sample also includes some transients with narrow and very broad light curves leading to more extreme ejecta masses values.
Ist Fliegen oder Tauchen riskant für CI-Träger? – Untersuchungen in einer Druckkammer
Authors: Nolte Antonia , Meyer Moritz , Luers Jan-Christoffer , Fürstenberg Dirk , Klussmann Jens Peter , Lang-Roth Ruth , Jansen Stefanie 
Published: January 2021

ZusammenfassungHintergrund Verglichen mit dem Zugewinn an Lebensqualität, den viele Patienten durch ein Cochlea-Implantat (CI) erfahren, bringt das CI nur wenige Einschränkungen im täglichen Leben mit sich. Doch kann man mit einem CI auch Tauchen und Fliegen? Halten das operierte Ohr sowie das Implantat selbst den ausgeprägten Druckveränderungen stand? Bisher gibt es keine klaren Empfehlungen und sehr wenig Literatur über die Risiken des Gerätetauchens sowie des Fliegens mit CI.Material und Methoden In einer hypo-/hyperbaren Druckkammer wurden Menschen mit einem CI einem Druckprofil mit Phasen des Druckanstiegs sowie Phasen des Druckabfalls ausgesetzt, sodass zunächst ein Flug und dann ein Tauchgang simuliert wurden. Sowohl vor als auch nach der Druckkammermessung erfolgten eine Ohrmikroskopie sowie eine Messung der Impedanzen des Cochlea-Implantats. Zusätzlich füllte jeder Patient einen symptombezogenen Fragebogen vor sowie nach der Druckkammermessung aus.Ergebnisse In der Druckkammer wurden insgesamt 17 CI-implantierte Ohren bei 11 Probanden untersucht. Zwei Drittel der Probanden gaben an, während der Untersuchung leichte Beschwerden gehabt zu haben. Bei einem Probanden musste die Messung aufgrund von Schmerzen abgebrochen werden. Sieben Patienten zeigten im Anschluss an die Druckexposition eine Hammergefäßinjektion in der Ohrmikroskopie. Bei keinem der Patienten kam es nach der Untersuchung zu einer subjektiven Hörverschlechterung. Es kam zu keiner relevanten Änderung der Impedanzen des CI-Implantats.Schlussfolgerung Die Exposition mit Unter- und Überdruck bei Patienten mit Cochlea-Implantaten ergab in der objektiven Überprüfung der Impedanzen keine wesentliche Abweichung der Impedanzen, sodass keine erneute Anpassung notwendig war. Allerdings zeigten sich leichtgradige Barotraumata sowie subjektive, leichte Beschwerden. Weitere Studien sind erforderlich, um eine adäquate Risikoeinschätzung zur Druckexposition bei CI-Trägern geben zu können.
Combined chemotherapy and endoscopic ultrasound-guided intratumoral 32P implantation for locally advanced pancreatic adenocarcinoma: a pilot study
Authors: Naidu Jeevinesh , Bartholomeusz Dylan , Zobel Joshua , Safaeian Romina , Hsieh William , Crouch Benjamin , Ho Karen , Calnan Deborah , Singhal Nimit , Ruszkiewicz Andrew , Chen John W. , Tan Chuan Ping , Dolan Paul , Nguyen Nam Q. 
Published: January 2021

Abstract
Background This study evaluated clinical outcomes of combined chemotherapy and endoscopic ultrasound (EUS)-guided intratumoral radioactive phosphorus-32 (32P) implantation in locally advanced pancreatic adenocarcinoma (LAPC).
Methods Consecutive patients with newly diagnosed LAPC were recruited over 20 months. Baseline computed tomography and 18F-2-fluoro-2-deoxy-D-glucose (18FDG) positron emission tomography–computed tomography were performed and repeated after 12 weeks to assess treatment response. Following two cycles of conventional chemotherapy, patients underwent EUS-guided 32P implantation followed by six chemotherapy cycles.
Results 12 patients with LAPC (median age 69 years [interquartile range 61.5–73.3]; 8 male) completed treatment. Technical success was 100 % with no procedural complications. At 12 weeks, median reduction in tumor volume was 8.2 cm3 (95 % confidence interval 4.95–10.85; P = 0.003), with minimal or no 18FDG uptake in nine patients (75 %). Tumor downstaging was achieved in six patients (50 %), leading to successful resection in five (42 %), including four R0 resections (80 %).
Conclusions EUS-guided 32P implantation was feasible, well tolerated, and resulted in a 42 % surgical resection rate. Further evaluation in a larger randomized multicenter trial is warranted.
(4+1)-Cycloadditions Exploiting the Biphilicity of Oxyphosphonium Enolates and RhII/PdII-Stabilized Metallocarbenes for the Construction of Five-Membered Frameworks
Authors: Ashfeld Brandon L. , Tucker Zachary D. 
Published: January 2021

Abstract(4+1)-Cyclizations are an underutilized disconnect for the formation of five-membered heterocyclic and carbocyclic frameworks. Herein we analyze methods employing oxyphosphonium enolates and RhII/PdII-metallocarbenes as C1 synthons in the presence of several four-atom components for the synthesis of 2,3-dihydrobenzofurans, 2,3-dihydroindoles, oxazolones, cyclopentenones, and pyrrolones.1	Introduction2	(4+1)-Cyclizations Employing Kukhtin–Ramirez-Like Reactivity3	(4+1)-Cyclizations Employing a Cyclopropanation/Ring-Expansion Sequence4	Pd-Catalyzed (4+1)-Cyclizations through Carbene Migratory Insertion/Reductive Elimination Processes5	Summary
Synthesis of Functionalized 9-Substituted Fluorene Derivatives via Boron Trifluoride Catalysed Reaction of Coplanar 9-(Phenylethynyl)-9H-fluoren-9-ols, Aryl Aminoamides and N-Bromosuccinimide
Authors: Shanmugam Ponnusamy , Athira Mohanakumaran 
Published: January 2021

AbstractA boron trifluoride catalysed reaction of coplanar 9-(phenyl­ethynyl)-9H-fluoren-9-ols with various 2-aminobenzamides affords a number of highly functionalized, conjugated (Z)-2-((2-(9H-fluoren-9-ylidene)-1-phenylethylidene)amino) benzamides in excellent yield. The reaction in the presence of N-bromosuccinimide affords (E)-5-bromo-2-((2-bromo-2-(9H-fluoren-9-ylidene)-1-phenylethylidene)amino)benz­amides in very good yields. The scope of the reaction is demonstrated by selecting N-aryl substituted 2-aminobenzamides and aminosulfonamides as reaction partners. The structures of representative compounds were established by single-crystal XRD analysis. Based on the structure of the products, a plausible mechanism via formation of allene carbocation intermediates is proposed.
Double perspective in the Colonial present
Authors: Svalastog Anna Lydia , Wilson Shawn , Gaski Harald , Senior Kate , Chenhall Richard 
Published: January 2021

AbstractThis paper will explain the concept ofdouble perspectiveand the impact that this cultural understanding may have on the health of the Indigenous peoples of Scandinavia. In inter-cultural communication, one set of meanings may be discernible to the outsider while a whole extra set of restricted or underlying meanings are only accessible for those people who have the cultural knowledge to discern them. These different sets of meanings embody a double perspective. It is not dual perspectives on the same reality but rather seeing two separate but overlapping realities. We will discuss the layers of meaning which are involved in the interactions between public healthcare institutions, clinicians and staff, and Indigenous people including the Sámi. These interactions are influenced by the impact of colonization and the ongoing epistemicide of Indigenous thought. By realising the improved resilience that a double perspective brings to Indigenous peoples, an awareness of the inclusion and exclusion of Indigenous persons, cultures and histories should become established in public institutions and in everyday life. A double perspective carries Sámi resilience, and should be understood as a key to support individual health, and also the collective wellbeing of a people living on their traditional yet colonized land.
A cylindrical SiC heater for an externally heated diamond anvil cell to 1500 K
Authors: Okuda Yoshiyuki , Kimura Seiji , Ohta Kenji , Park Yohan , Wakamatsu Tatsuya , Mashino Izumi , Hirose Kei 
Published: January 2021

Semiconductor-based heaters for diamond anvil cells (DACs) have advantages over metal wire heaters in terms of repeated use and the ability to reach higher temperatures. We introduce a cylindrical SiC heater for an externally heated DAC (EHDAC) that works satisfactorily at temperatures up to 1500 K and pressures around 90 GPa. The heater is reusable and inexpensive, and only slight modifications to the DAC are required to fit the heater. Experiments on melting of NaCl and gold are conducted at ambient pressure to test the temperature accuracy of the EHDAC system, and resistance measurements on iodine at high pressures and temperatures are performed to assess the heater assembly. These test runs show that a uniform and accurate temperature can be maintained by the EHDAC assembly, which has potential applications to a variety of transport property measurements.
An accessible microwave cavity experiment for plasma density determination
Authors: Oliveira J , Hachmeister D , Lourenço P D , Brotankova J , Fernandes H 
Published: January 2021

Abstract
Plasmas are indissociable from microwave science. Effectively, the most fundamental properties of any plasma arise from its plasma frequency. However, combining plasma physics with electromagnetic (EM) wave propagation is challenging for physics students. An EM cavity poses an excellent opportunity to understand the behavior of EM standing waves, the issues related to transmitted and reflected power in waveguides, coupling, and how free charges in the plasma affect its resonant frequency and quality factor, interlinking the properties of matter with wave propagation. The inclusion of an external magnetic field allows students to explore the underlying principles of magnetic confinement in a linear geometry.
Anomalous diffusion, nonergodicity, and ageing for exponentially and logarithmically time-dependent diffusivity: striking differences for massive versus massless particles
Authors: Cherstvy Andrey G , Safdari Hadiseh , Metzler Ralf 
Published: January 2021

Abstract
We investigate a diffusion process with a time-dependent diffusion coefficient, both exponentially increasing and decreasing in time,

D
(
t
)
=

D
0

e

±
2
α
t

. For this (hypothetical) nonstationary diffusion process we compute—both analytically and from extensive stochastic simulations—the behavior of the ensemble- and time-averaged mean-squared displacements (MSDs) of the particles, both in the over- and underdamped limits. Simple asymptotic relations derived for the short- and long-time behaviors are shown to be in excellent agreement with the results of simulations. The diffusive characteristics in the presence of ageing are also considered, with dramatic differences of the over- versus underdamped regime. Our results for

D
(
t
)
=

D
0

e

±
2
α
t

extend and generalize the class of diffusive systems obeying scaled Brownian motion featuring a power-law-like variation of the diffusivity with time,

D
(
t
)
∼

t

α
−
1

. We also examine the logarithmically increasing diffusivity,

D
(
t
)
=

D
0

log
[
t
/

τ
0

]

, as another fundamental functional dependence (in addition to the power-law and exponential) and as an example of diffusivity slowly varying in time. One of the main conclusions is that the behavior of the massive particles is predominantly ergodic, while weak ergodicity breaking is repeatedly found for the time-dependent diffusion of the massless particles at short times. The latter manifests itself in the nonequivalence of the (both nonaged and aged) MSD and the mean time-averaged MSD. The current findings are potentially applicable to a class of physical systems out of thermal equilibrium where a rapid increase or decrease of the particles’ diffusivity is inherently realized. One biological system potentially featuring all three types of time-dependent diffusion (power-law-like, exponential, and logarithmic) is water diffusion in the brain tissues, as we thoroughly discuss in the end.
Investigating the energetic and entropic components of effective potentials across a glass transition
Authors: Szukalo Ryan J , Noid W G 
Published: January 2021

Abstract
By eliminating unnecessary details, coarse-grained (CG) models provide the necessary efficiency for simulating scales that are inaccessible to higher resolution models. However, because they average over atomic details, the effective potentials governing CG degrees of freedom necessarily incorporate significant entropic contributions, which limit their transferability and complicate the treatment of thermodynamic properties. This work employs a dual-potential approach to consider the energetic and entropic contributions to effective interaction potentials for CG models. Specifically, we consider one- and three-site CG models for ortho-terphenyl (OTP) both above and below its glass transition. We employ the multiscale coarse-graining (MS-CG) variational principle to determine interaction potentials that accurately reproduce the structural properties of an all-atom (AA) model for OTP at each state point. We employ an energy-matching variational principle to determine an energy operator that accurately reproduces the intra- and inter-molecular energy of the AA model. While the MS-CG pair potentials are almost purely repulsive, the corresponding pair energy functions feature a pronounced minima that corresponds to contacting benzene rings. These energetic functions then determine an estimate for the entropic component of the MS-CG interaction potentials. These entropic functions accurately predict the MS-CG pair potentials across a wide range of liquid state points at constant density. Moreover, the entropic functions also predict pair potentials that quite accurately model the AA pair structure below the glass transition. Thus, the dual-potential approach appears a promising approach for modeling AA energetics, as well as for predicting the temperature-dependence of CG effective potentials.
Self-diffusion of nonspherical particles fundamentally conflicts with effective sphere models
Authors: Roosen-Runge Felix , Schurtenberger Peter , Stradner Anna 
Published: January 2021

Abstract
Modeling diffusion of nonspherical particles presents an unsolved and considerable challenge, despite its importance for the understanding of crowding effects in biology, food technology and formulation science. A common approach in experiment and simulation is to map nonspherical objects on effective spheres to subsequently use the established predictions for spheres to approximate phenomena for nonspherical particles. Using numerical evaluation of the hydrodynamic mobility tensor, we show that this so-called effective sphere model fundamentally fails to represent the self-diffusion in solutions of ellipsoids as well as rod-like assemblies of spherical beads. The effective sphere model drastically overestimates the slowing down of self-diffusion down to volume fractions below 0.01. Furthermore, even the linear term relevant at lower volume fraction is inaccurate, linked to a fundamental misconception of effective sphere models. To overcome the severe problems related with the use of effective sphere models, we suggest a protocol to predict the short-time self-diffusion of rod-like systems, based on simulations with hydrodynamic interactions that become feasible even for more complex molecules as the essential observable shows a negligible system-size effect.
The phase diagram of Ti-6Al-4V at high-pressures and high-temperatures
Authors: MacLeod S G , Errandonea D , Cox G A , Cynn H , Daisenberger D , Finnegan S E , McMahon M I , Munro K A , Popescu C , Storm C V 
Published: January 2021

Abstract
We report results from a series of diamond-anvil-cell synchrotron x-ray diffraction and large-volume-press experiments, and calculations, to investigate the phase diagram of commercial polycrystalline high-strength Ti-6Al-4V alloy in pressure–temperature space. Up to ∼30 GPa and 886 K, Ti-6Al-4V is found to be stable in the hexagonal-close-packed, or α phase. The effect of temperature on the volume expansion and compressibility of α–Ti-6Al-4V is modest. The martensitic α → ω (hexagonal) transition occurs at ∼30 GPa, with both phases coexisting until at ∼38–40 GPa the transition to the ω phase is completed. Between 300 K and 844 K the α → ω transition appears to be independent of temperature. ω–Ti-6Al-4V is stable to ∼91 GPa and 844 K, the highest combined pressure and temperature reached in these experiments. Pressure–volume–temperature equations-of-state for the α and ω phases of Ti-6Al-4V are generated and found to be similar to pure Ti. A pronounced hysteresis is observed in the ω–Ti-6Al-4V on decompression, with the hexagonal structure reverting back to the α phase at pressures below ∼9 GPa at room temperature, and at a higher pressure at elevated temperatures. Based on our data, we estimate the Ti-6Al-4V α–β–ω triple point to occur at ∼900 K and 30 GPa, in good agreement with our calculations.
A NIST facility for resonant soft x-ray scattering measuring nano-scale soft matter structure at NSLS-II
Authors: Gann Eliot , Crofts Thomas , Holland Glenn , Beaucage Peter , McAfee Terry , Kline R Joseph , Collins Brian A , McNeill Christopher R , Fischer Daniel A , DeLongchamp Dean M 
Published: January 2021

Abstract
We present the design and performance of a polarized resonant soft x-ray scattering (RSoXS) station for soft matter characterization built by the national institute of standards and technology at the national synchrotron light source-II (NSLS-II). The RSoXS station is located within the spectroscopy soft and tender beamline suite at NSLS-II located in Brookhaven national laboratory, New York. Numerous elements of the RSoXS station were designed for optimal performance for measurements on soft matter systems, where it is of critical importance to minimize beam damage and maximize collection efficiency of polarized x-rays. These elements include a novel optical design, sample manipulator and sample environments, as well as detector setups. Finally, we will report the performance of the measurement station, including energy resolution, higher harmonic content and suppression methods, the extent and mitigation of the carbon absorption dip on optics, and the range of polarizations available from the elliptically polarized undulator source.
Physical processes determining plasma confinement in tokamaks with transport barriers from the point of view of self-organization
Authors: Razumova K A , Andreev V F , Eliseev L G , Kantor M Y , Kasyanova N V , Lysenko S E , Melnikov A V 
Published: January 2021

Abstract
The goal of this article is to describe processes linked to energy confinement in tokamak plasmas from the perspective of self-organization—the main process that determines the behavior of turbulent plasmas. In the paper Razumova et al 2020 Plasma Phys. Rep.
46 337, such an analysis was performed for regimes without transport barriers. The present paper extends this approach to regimes with barriers and magnetic islands. In a shorter version, it was presented in Razumova et al 2020 Entropy
22 53, which showed that the appearance of islands in the inner part of the barrier is directly related to the formation of the barrier and limits its growth. We discuss the structure of the radial heat flux that carries energy from the plasma in such a way that the pressure profile remains close to the self-consistent profile (as observed in the experiment).
Method for estimating the frequency-wavenumber resolved power spectrum density using the maximum entropy method for limited spatial points
Authors: Kobayashi T , Nishizawa T , Sasaki M , Yoshinuma M , Ida K 
Published: January 2021

Abstract
A combination of the Fourier transform and the maximum entropy method for estimating the frequency-wavenumber resolved power spectrum density is proposed. After illustrating the physical insight of the maximum entropy method by using synthetic test data, capability of the proposed method is tested using numerical simulation data. The method is also applied to experimental data obtained by the beam emission spectroscopy in the Large Helical Device. All of those examinations show that the proposed method provides more plausible results than conventional methods when the available spatial points are limited.