bluuebunny/crossref_metadata_2025_split huggingface dataset:
The vibrational and thermodynamic properties of hydrogen adsorbed on the Pt(100) surface: a theoretical study
Authors: Nguyen Van Hoa , Nguyen Minh Phi , Lam Toan Vi , Tran Thi Thu Hanh 
Published: January 2022

Abstract
The adsorption of hydrogen on the Pt(100) surface is investigated theoretically within the conventional ultrahigh vacuum (UHV) surface modeling. Both density functional theory (DFT) and Monte Carlo (MC) simulation are implemented to determine the stability, the vibrational properties of the adsorbed hydrogen atom, and the H-H pair interactions. From the converged data, it is found that the H adsorbed on the bridge sites (B sites) have the strongest binding energy. Meanwhile, the H adsorbed on the top sites (T sites) have the highest vertical stretching frequency. In the increment of H coverage (

Θ

H

), up to 1 ML, only the H on the B sites are counted. The shape of the g-value curve obtained by MC simulation shows a good agreement with the result of the cyclic voltammetry (CV) measurement. Reducing the pair interaction parameters by about 30%, the g-value is also decreased. From 0.3 to 0.6 with respect to

Θ

H

,

the g-value is extremely fitted to the experimental data. This indicates that the interactions of H-H on the Pt(100) surface within the range of

0.3
<

Θ

H

<
0.6

are mainly attributed to those hydrogen atoms adsorbed on the B sites.
Bouncing cosmological isotropic solutions in scalar-tensor gravity
Authors: Polarski D. , Starobinsky A.A. , Verbin Y. 
Published: January 2022

Abstract
Bouncing non-singular isotropic cosmological solutions are investigated in a simple model of scalar-tensor gravity. New families of such solutions are found and their properties are presented and analyzed
using an effective potential as the main tool.
Bouncing solutions are shown to exist for a Higgs-like self-interaction
potential which is bounded from below, in contrast to previous solutions that appeared in the literature based on potentials which were unbounded from below. In the simplest version of a scalar field with the quartic potential and conformal coupling to gravity, bouncing spatially flat solutions either have the Hubble function diverging in the past before
the bounce, but with a well-behaved future, or are globally regular but unstable with respect to anisotropic or inhomogeneous
perturbations at some finite values of the scalar field and curvature. Regular solutions can only exist in the part of the parameter space where the maximum of
the effective potential is larger than the first zero of the potential, and gravity becomes
repulsive at the bounce.
On the duality of massive Kalb-Ramond and Proca fields
Authors: Hell Anamaria 
Published: January 2022

Abstract
We compare the massive Kalb-Ramond and Proca fields with a quartic self-interaction and show that the same strong coupling scale is present in both theories. In the Proca theory, the longitudinal mode enters the strongly coupled regime beyond this scale, while the two transverse modes propagate further and survive in the massless limit. In contrast, in case of the massive Kalb-Ramond field, the two transverse modes become strongly coupled beyond the Vainshtein scale, while the pseudo-scalar mode remains in the weak coupling regime and survives in the massless limit. This indicates a contradiction with the numerous claims in the literature (see eg. [3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21]) that these theories are dual to each other.
Gravitational waves from melting cosmic strings
Authors: Emond William T. , Ramazanov Sabir , Samanta Rome 
Published: January 2022

Abstract
Appearance of cosmic strings in the early Universe is a common manifestation of new physics typically linked to some high energy scale. In this paper, we discuss a different situation, where a model underlying cosmic string formation is approximately scale free. String tension is naturally related to the square of the temperature of the hot primordial plasma in such a setting, and hence decreases with (cosmic) time. With gravitational backreaction neglected, the dynamics
of these melting strings in an expanding Universe is equivalent to the dynamics of constant tension strings in a Minkowski spacetime.
We provide an estimate for the emission of gravitational waves from string loops. Contrary to the standard case, the resulting spectrum is markedly non-flat and has a characteristic falloff
at frequencies below the peak one. The peak frequency is defined by the underlying model and lies in the range accessible by the future detectors for very weak couplings involved.
Cytoskeletal proteins: lessons learned from bacteria
Authors: Ramos-León Félix , Ramamurthi Kumaran S 
Published: January 2022

Abstract
Cytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as ‘cytoskeletal’. However, several bacteria encode other proteins capable of polymerizing which, although they do not appear to have a eukaryotic counterpart, nonetheless appear to perform a more traditional ‘cytoskeletal’ function. In this review, we discuss recent reports that cover the structures and functions of prokaryotic proteins that are broadly termed as cytoskeletal, either by sequence homology or by function, to highlight how the enzymatic properties of traditionally studied cytoskeletal proteins may be used for other types of cellular functions; and to demonstrate how truly ‘cytoskeletal’ functions may be performed by uniquely bacterial proteins that do not display homology to eukaryotic proteins.
Extension of NIM illuminance scale to very low levels (1 × 10−10 lx to 2 lx)
Authors: Lv Liang , Jiang Xiaomei , Lin Yandong , Li Jian , Lin Xiaofeng , Xu Ning 
Published: January 2022

Abstract
The realization of the low light level illuminance scale of the National Institute of Metrology (NIM, China) is presented. Two methods were used to achieve the photometric scale covering (1 × 10−10–2 × 100) lx, the first method based on the luminance adjustable two-stage integrating sphere source was used to realize the illuminance scale down to 1 × 10−6 lx, while the other method based on a twin-source superposition linearity measurement facility was applied to extend the scale from 1 × 10−6 lx to 1 × 10−10 lx. The expanded relative uncertainty of the (1 × 10−10–2 × 100) lx illuminance scale was evaluated to be from 1.0 % to 0.8 % varying with range (coverage factor k = 2). As part of our research work, a photon counting type photometer was developed and calibrated in the (2 × 10−10–1 × 10−6) lx range using this low light level illuminance scale with expanded relative uncertainty 13 % to 1.4 % (k = 2). This low light level photometric scale can meet the calibration requirement of high sensitivity photometers such as the micro-lux photometers and photon counting type photometers.
Quality assessment of cadmium telluride as a detector material for multispectral medical imaging
Authors: Kirschenmann S. , Bezak M. , Bharthuar S. , Brücken E. , Golovleva M. , Gädda A. , Kalliokoski M. , Karadzhinova-Ferrer A. , Koponen P. , Kramarenko N. , Luukka P. , Ott J. , Tikkanen J. , Turpeinen R. , Winkler A. 
Published: January 2022

Abstract
Cadmium telluride (CdTe) is a high-Z material with excellent photon radiation absorption properties, making it a promising material to include in radiation detection technologies. However, the brittleness of CdTe crystals as well as their varying concentration of defects necessitate a thorough quality assessment before the complex detector processing procedure. We present our quality assessment of CdTe as a detector material for multispectral medical imaging, a research which is conducted as part of the Consortium Project Multispectral Photon-counting for Medical Imaging and Beam characterization (MPMIB). The aim of the project is to develop novel CdTe detectors and obtain spectrum-per-pixel information that make the distinction between different radiation types and tissues possible. To evaluate the defect density inside the crystals — which can deteriorate the detector performance — we employ infrared microscopy (IRM). Posterior data analysis allows us to visualise the defect distributions as 3D defect maps. Additionally, we investigate front and backside differences of the material with current-voltage (IV) measurements to determine the preferred surface for the pixelisation of the crystal, and perform test measurements with the prototypes to provide feedback for further processing. We present the different parts of our quality assessment chain and will close with first experimental results obtained with one of our prototype photon-counting detectors in a small tomographic setup.
Design of a new reflectometric system for real time plasma position control on the RFX-mod2 device
Authors: De Masi G. , Cavazzana R. , Abate D. , Bernardi M. , Marchiori G. , Moresco M. , Tiso A. , Peruzzo S. 
Published: January 2022

Abstract
RFX-mod2 (R = 2.0 m, a = 0.49 m), the upgraded version of the previous RFXmod fusion device, will be equipped with a new reflectometry system specifically designed for plasma position control purposes. Featuring a high temporal and spatial resolution and being suitable for harsh fusion reactor experimental conditions (long pulses, high neutron fluxes), reflectometry has been proposed as a good candidate for this task. On RFX-mod2 the diagnostic system will consist of four bistatic ultrafast independent reflectometric units working in the frequency range (16–26.5 GHz) and installed in four different poloidal locations at the same toroidal angle: two on the equatorial plane (high field side/low field side) and two at the vertical top/bottom ports. Standard pyramidal horns will be installed in the external midplane and in the vertical ports, while parabolic hoghorn reflectors have been designed for the internal midplane. Different technical solutions for the integration in the machine, as the additive manufacturing for the antenna production, are presented. Despite the differences with respect to the application on large Tokamaks like DEMO, the RFX-mod2 plasma position reflectometer can contribute to test on a simple machine some of the issues related to the development of a reflectometry based plasma position and shape control.
A 5-Gbps serializer ASIC in 130 nm for high-speed front-end readout applications
Authors: Meng C. , Guo T. , Xiong T. , Chen Q. , Guo Z. , Zhao C. , Guo D. 
Published: January 2022

Abstract
This paper presents the design and the test results of a low-power 5 Gbps 10:1 serializer chip with the self-check function based on a standard 130 nm CMOS technology. This serializer chip adopts a multi-level design scheme with a combination of the multi-phase structure (5:1 module) in the low data rate part and the tree structure (2:1 module) in the high date rate part. The high data rate 2:1 module adopts a latch-induced latency control circuit to ensure the timing margin across corners. The serializer chip has been fully tested, wide-open 5 Gbps output eye diagram has been captured, and the logic function has also been verified. The measured power consumption of the whole chip is 42 mW including Rx/Tx, and the power consumption of the serializer core is around 12.1 mW.
First GEM measurements at WEST and perspectives for fast electrons and heavy impurities transport studies in tokamaks
Authors: Mazon D. , Chernyshova M. , Jardin A. , Peysson Y. , Król K. , Malard P. , Czarski T. , Wojeński A. , Malinowski K. , Colette D. , Poźniak K.T. , Kasprowicz G. , Zabołotny W. , Krawczyk R.D. , Kolasiński P. , Gąska M. , Linczuk P. , Bielecki J. , Scholz M. , Dworak D. 
Published: January 2022

Abstract
Soft X-ray (SXR) radiation emitted from tokamak plasmas contains very useful information about plasma stability, shape and impurity content, all key parameters to improve plasma performance. In the deuterium-tritium phase of ITER, the high neutron fluxes, gamma and hard X-ray emission will constitute too harsh an environment to permit the use of classical semiconductor detectors. New SXR detector technologies, more robust to such environments, should thus be investigated. First GEM (Gas Electron Multiplier) measurements performed at WEST were successful and showed that both spatially and spectrally resolved calibrated data could be acquired. Strategies to reconstruct tungsten (W) impurity radiation synthetic diagnostics, modelling and real measurements based on multiple diagnostics are proposed.
Validity and validation in archetype analysis: practical assessment framework and guidelines
Authors: Piemontese Luigi , Neudert Regina , Oberlack Christoph , Pedde Simona , Roggero Matteo , Buchadas Ana , Martin Dominic A , Orozco Richard , Pellowe Kara , Segnon Alcade C , Zarbá Lucía , Sietz Diana 
Published: January 2022

Abstract
Archetype analysis is a promising approach in sustainability science to identify patterns and explain mechanisms shaping the sustainability of social-ecological systems. Although considerable efforts have been devoted to developing quality standards and methodological advances for archetype analysis, archetype validation remains a major challenge. Drawing on the insights from two international workshops on archetype analysis and on broader literature on validity, we propose a framework that identifies and describes six dimensions of validity: conceptual; construct; internal; external; empirical; and application validity. We first discuss the six dimensions in relation to different methodological approaches and purposes of archetype analysis. We then present an operational use of the framework for researchers to assess the validity of archetype analysis and to support sound archetype identification and policy-relevant applications. Finally, we apply our assessment to 18 published archetype analyses, which we use to describe the challenges and insights in validating the different dimensions and suggest ways to holistically improve the validity of identified archetypes. With this, we contribute to more rigorous archetype analyses, helping to develop the potential of the approach for guiding sustainability solutions.
Improvement of impact toughness by microstructure refinement of simulated CGHAZ through enhancing welding heat input of low carbon Mo-V-Ti-N-B steel
Authors: Fan Huibing , Shi Genhao , Wang Qiuming , Wang Leping , Wang Qingfeng , Zhang Fucheng 
Published: January 2022

Abstract
Welding heat input greatly influences the microstructure and impacts the affected zone’s toughness. To interpret the relationships between the welding heat input, microstructure, and low-temperature toughness of the coarse-grained heat-affected zone (CGHAZ) of Mo-V-Ti-N-B steels, welding heat cycles with different heat inputs (25–75 kJ cm−1) were performed on a Gleeble 3500 simulator. Intragranular ferrite in the simulated samples subjected to different thermal cycles was characterized and quantified, and the impact energies of simulated samples were evaluated at −20 °C. Upon increasing the heat input, the intragranular ferrite content rose sharply from 4.3% to 76.0%. The V(C, N) enrichment on the precipitate surface increased the size of precipitates, providing favourable nucleation conditions for intragranular ferrite. The prior austenite grain (PAG) and martensite/austenite (M/A) constituents became rough, and the content of the M/A constituent increased while the impact energy of the CGHAZ increased. This behaviour occurred due to the formation of intragranular acicular ferrite (IGAF), which refined the microstructure of the CGHAZ. Grain refinement eliminated the negative influence of higher M/A content on the impact toughness of the CGHAZ.
Design and modeling of a high resolution and high sensitivity PET brain scanner with double-ended readout
Authors: Layden Christopher , Klein Kyle , Matava William , Sadam Akhil , Abouzahr Firas , Proga Marek , Majewski Stanislaw , Nuyts Johan , Lang Karol 
Published: January 2022

Abstract
In the wake of recent advancements in scintillator, photodetector, and low-noise fast electronics technologies, as well as in fast reconstruction software, positron emission tomography (PET) scanners have seen considerable improvements in spatial resolution, time resolution, and absolute sensitivity. To continue this trend, we present a helmet type PET brain scanner design that combines high solid angle coverage and double-ended readout of 30 mm-thick scintillator crystals to achieve excellent absolute sensitivity, depth of interaction resolution, and time resolution. This scanner comprises 598 detector arrays, each with 8 × 8 Lu1.8Y0.2SiO5:Ce (LYSO:Ce) crystals with dimensions 3.005 × 3.005 × 30 mm3 one-to-one coupled on either end to silicon photomultipliers (SiPMs). Our Monte Carlo simulations based in the platform Geant4 predict that this scanner would attain an absolute sensitivity to a 35 cm line source placed at the center of the radial field of view of (17.1 ± 0.1)%, a depth of interaction resolution of (3.99 ± 0.05) mm, and a coincidence time resolution of (198 ± 5) ps. Our simulations also predict radial, tangential, and axial spatial resolutions at the center of the field of view of 3.3 mm, 3.1 mm, and 3.3 mm, respectively. As this set of simultaneous parameters compares favorably to today’s most advanced clinical PET scanners and other proposed designs, this scanner has a good chance of becoming a preferred tool for high quality brain imaging.
Neutron yield measurement system of HL-2A tokamak
Authors: YUAN Guoliang , WEN Zuowei , WEI Lingfeng , ZHANG Jinwen , YANG Qingwei 
Published: January 2022

Abstract
This research presents the development of HL-2A neutron yield measurement which includes 235U fission chamber and BF3 and 3He proportional counters. Equivalent noise formula of the radiation detection signal amplification system was derived to guide the development of the signal amplification system. Then all detectors were calibrated in situ by using the 252Cf neutron source. The neutron yield of the HL-2A during neutral beam heating was analyzed. These results indicate that the developed neutron flux diagnostic system can obtain neutron yield results under various experimental conditions of the HL-2A tokamak, and can provide information on neutron yield.
Sample complexity of learning parametric quantum circuits
Authors: Cai Haoyuan , Ye Qi , Deng Dong-Ling 
Published: January 2022

Abstract
Quantum computers hold unprecedented potentials for machine learning applications. Here, we prove that physical quantum circuits are probably approximately correct learnable on a quantum computer via empirical risk minimization: to learn a parametric quantum circuit with at most n

c
gates and each gate acting on a constant number of qubits, the sample complexity is bounded by

O

~

(

n

c
+
1

)

. In particular, we explicitly construct a family of variational quantum circuits with O(n

c+1) elementary gates arranged in a fixed pattern, which can represent all physical quantum circuits consisting of at most n

c
elementary gates. Our results provide a valuable guide for quantum machine learning in both theory and practice.
New procedure to estimate plasma parameters through the q-Weibull distribution by using a Langmuir probe in a cold plasma
Authors: Gonzalez F J , Gonzalez J I , Soler S , Repetto C E , Gómez B J , Berdichevsky D B 
Published: January 2022

AbstractWe describe a procedure to obtain the plasma parameters from theI-VLangmuir curve by using the Druyvesteyn equation. We propose to include two new parameters,qandr, to the usual plasma parameters: plasma potential (Vp), floating potential (Vf), electron density (n), and electron temperature (T). These new parameters can be particularly useful to represent non-Maxwellian distributions. The procedure is based on the fit of theI-VLangmuir curve with theq-Weibull distribution function, and is motivated by recent works which use theq-exponential distribution function derived from Tsallis statistics. We obtain the usual plasma parameters employing three techniques: the numerical differentiation using Savitzky Golay (SG) filters, theq-exponential distribution function, and theq-Weibull distribution function. We explain the limitations of theq-exponential function, where the experimental dataV>Vpneeds to be trimmed beforehand, and this results in a lower accuracy compared to the numerical differentiation with SG. To overcome this difficulty, theq-Weibull function is introduced as a natural generalization to theq-exponential distribution, and it has greater flexibility in order to represent the concavity change aroundVp. We apply this procedure to analyze the measurements corresponding to a nitrogenN2cold plasma obtained by using a single Langmuir probe located at different heights from the cathode. We show that theqparameter has a very stable numerical value with the height. This work may contribute to clarify some advantages and limitations of the use of non-extensive statistics in plasma diagnostics, but the physical interpretation of the non-extensive parameters in plasma physics remains not fully clarified, and requires further research.
New estimates for the maximal functions and applications
Authors: Domínguez Óscar , Tikhonov Sergey 
Published: January 2022

In this paper we study sharp pointwise inequalities for maximal operators. In particular, we strengthen DeVore’s inequality for the moduli of smoothness and a logarithmic variant of Bennett–DeVore–Sharpley’s inequality for rearrangements. As a consequence, we improve the classical Stein–Zygmund embedding deriving

B
˙

∞

d

/

p

L

p
,
∞

(

R

d

)
↪
BMO
(

R

d

)

\dot {B}^{d/p}_\infty L_{p,\infty }(\mathbb {R}^d) \hookrightarrow \text {BMO}(\mathbb {R}^d)

for

1
>
p
>
∞

1 > p > \infty

. Moreover, these results are also applied to establish new Fefferman–Stein inequalities, Calderón–Scott type inequalities, and extrapolation estimates. Our approach is based on the limiting interpolation techniques.
Learning about sites of care for older adults: a jigsaw educational session for medical students
Authors: Goreshnik Ashley , Corey Matthew T , Rhodes Kropf Jennifer , Schwartz Andrea Wershof 
Published: January 2022

Abstract
Choosing the appropriate site of care for patients is a vital clinical skill when caring for older adults. For better patient safety and smoother transitions of care, we need improved curricula to train clinicians about the system of sites and services where older adults receive care. Here we present an innovative introduction for medical trainees to the complexities of long-term and post-acute care for geriatric patients. Students participated in a team-based ‘jigsaw’ learning activity, in which each team researched a particular site of care and then taught a larger group of their peers about that site. It was subsequently converted to a virtual format due to COVID-19. The activity was assessed using students’ written feedback and satisfaction scores. Students enjoyed the interactivity and hands-on approach, giving the activity an average score of 3.9 out of 5 (1 = ‘poor’; 5 = ‘excellent’). The jigsaw provided an engaging, case-based foundation for learning about sites of care and was well-received by students.