bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bond dissociation energies of diatomic transition metal nitrides
Authors: Merriles Dakota M. , Knapp Annie S. , Barrera-Casas Yexalen , Sevy Andrew , Sorensen Jason J. , Morse Michael D. 
Published: February 2023

Resonant two-photon ionization (R2PI) spectroscopy has been used to measure the bond dissociation energies (BDEs) of the diatomic transition metal nitrides ScN, TiN, YN, MoN, RuN, RhN, HfN, OsN, and IrN. Of these, the BDEs of only TiN and HfN had been previously measured. Due to the many ways electrons can be distributed among the d orbitals, these molecules possess an extremely high density of electronic states near the ground separated atom limit. Spin–orbit and nonadiabatic interactions couple these states quite effectively, so that the molecules readily find a path to dissociation when excited above the ground separated atom limit. The result is a sharp drop in ion signal in the R2PI spectrum when the molecule is excited above this limit, allowing the BDE to be readily measured. Using this method, the values D0(ScN) = 3.905(29) eV, D0(TiN) = 5.000(19) eV, D0(YN) = 4.125(24) eV, D0(MoN) = 5.220(4) eV, D0(RuN) = 4.905(3) eV, D0(RhN) = 3.659(32) eV, D0(HfN) = 5.374(4) eV, D0(OsN) = 5.732(3) eV, and D0(IrN) = 5.115(4) eV are obtained. To support the experimental findings, ab initio coupled-cluster calculations extrapolated to the complete basis set limit (CBS) were performed. With a semiempirical correction for spin–orbit effects, these coupled-cluster single double triple-CBS calculations give a mean absolute deviation from the experimental BDE values of 0.20 eV. A discussion of the periodic trends, summaries of previous work, and comparisons to isoelectronic species is also provided.
Social Frailty Index: Development and validation of an index of social attributes predictive of mortality in older adults
Authors: Shah Sachin J. , Oreper Sandra , Jeon Sun Young , Boscardin W. John , Fang Margaret C. , Covinsky Kenneth E. 
Published: February 2023

While social characteristics are well-known predictors of mortality, prediction models rely almost exclusively on demographics, medical comorbidities, and function. Lacking an efficient way to summarize the prognostic impact of social factor, many studies exclude social factors altogether. Our objective was to develop and validate a summary measure of social risk and determine its ability to risk-stratify beyond traditional risk models. We examined participants in the Health and Retirement Study, a longitudinal, survey of US older adults. We developed the model from a comprehensive inventory of 183 social characteristics using least absolute shrinkage and selection operator, a penalized regression approach. Then, we assessed the predictive capacity of the model and its ability to improve on traditional prediction models. We studied 8,250 adults aged ≥65 y. Within 4 y of the baseline interview, 22% had died. Drawn from 183 possible predictors, the Social Frailty Index included age, gender, and eight social predictors: neighborhood cleanliness, perceived control over financial situation, meeting with children less than yearly, not working for pay, active with children, volunteering, feeling isolated, and being treated with less courtesy or respect. In the validation cohort, predicted and observed mortality were strongly correlated. Additionally, the Social Frailty Index meaningfully risk-stratified participants beyond the Charlson score (medical comorbidity index) and the Lee Index (comorbidity and function model). The Social Frailty Index includes age, gender, and eight social characteristics and accurately risk-stratifies older adults. The model improves upon commonly used risk prediction tools and has application in clinical, population health, and research settings.
Inside the echo chamber
Authors: Cheng Xi 
Published: February 2023

Abstract
In the context of the China-USA trade dispute, this study reports a discourse analysis of legitimation tactics used in the People’s Daily, a major English-language news outlet produced by the Communist Party of China (CPC). My analysis centres on a dataset of 65 commentaries between March 2018 and January 2020, and identifies the five key tactics at work: authorization, moralization, rationalization, hypothetical future, and integration. These tactics (and their sub-tactics) are deployed for delegitimating the US-initiated “America First” trade policy, and for legitimating the Chinese state’s position and countermeasures. Orienting to Western scholarship about the news media’s role as an “echo chamber” for State/political agendas, I compare the pattern of legitimation in the People’s Daily commentaries with the pattern previously found in an analysis of Chinese state white papers. This comparison highlights key similarities but also differences in terms of genre, language, and ideological coherence.
Dynamics of charged hyperbolically symmetric matter in modified gravity
Authors: Bhatti M Z , Yousaf Z , Tariq Z 
Published: February 2023

Abstract
We have conducted an in-depth investigation of static anisotropic matter configurations surrounded by electromagnetic field and possessing hyperbolically symmetric geometry by examining their physical characteristics in the framework of Palatini version of f(R) gravitational theory. Choosing the comoving coordinates, we define a canonical orthonormal tetrad and obtain the components of stress-energy tensor in locally Minkowskian frame. Working out the Palatini–Maxwell equations and the interior mass function for such a symmetry, it comes out that the energy density appears as a negative quantity which results in the development of a vacuole in the vicinity of the central region of the symmetry depicting that this region cannot be occupied by matter. We have also assessed the hydrostatic equilibrium equation and the source of tidal forces for the symmetry (i.e. Weyl scalar) and the active gravitational mass. Few scalar functions are then obtained out of the orthogonal decomposition of the Riemann curvature tensor and are utilized for the comprehension of physical characteristics of the matter configuration. Certain explicit solutions to the Palatini–Maxwell equations are also rendered with the help of two physical variables acting as generating functions.
Medical gamma cameras in radiological emergency preparedness: determination of calibration factors and MDA for the GE Discovery NM/CT 670 Pro
Authors: Hjellström Martin , Isaksson Mats 
Published: February 2023

Abstract
A survey was performed of the available gamma camera models and whole-body counters (WBCs) in Sweden, revealing that there are about 75 gamma cameras and 15 WBCs currently in operation in Sweden. One of the most common gamma camera models (GE Discovery NM/CT 670 Pro), with the collimators removed, was calibrated for 152Eu, 137Cs, 60Co and 40K in three different measurement geometries (supine, close-up sitting and distant sitting) for six different phantom sizes (12–110 kg). Minimum detectable activities (MDAs) were calculated for the gamma camera and a typical WBC, both at the Sahlgrenska University Hospital in Gothenburg, Sweden. An energy window of 30–510 keV was used to calibrate the gamma camera. The calibration factors for this gamma camera for supine and close-up sitting geometry, including all phantom sizes, were 138–208 cps kBq−1 for 152Eu, 63–83 cps kBq−1 for 137Cs and 99–126 cps kBq−1 for 60Co; the MDAs were 50–73 Bq for 152Eu, 125–198 Bq for 137Cs and 83–105 Bq for 60Co. The International Commission on Radiological Protection dose coefficients for members of the public were used to calculate the committed effective doses (CEDs) corresponding to the MDAs, showing that CEDs down to a few μSv can be estimated with this gamma camera for the inhalation of aerosols of absorption type M. The distant sitting geometry was used to enable the estimation of higher contamination levels, and a hypothetical maximum CED was calculated. This was shown to be 256–2000 mSv, depending on the radionuclide and phantom size. However, further investigations are needed into the dead time losses for higher activity levels for the radionuclides studied. The results show that the use of gamma cameras for radiological triage and, in some cases, to estimate the internal activity of relevant radionuclides in radiological and nuclear events, is feasible.
Defect detection algorithm for magnetic particle inspection of aviation ferromagnetic parts based on improved DeepLabv3+
Authors: Zeng Lu , Zhang Shouming , Wang Pengju , Li Zuze , Hu Yongjin , Xie Tao 
Published: February 2023

Abstract
Non-destructive testing (NDT) of magnetic materials such as aviation parts is an indispensable part of the civil aviation maintenance industry. The NDT of such metal materials often uses magnetic particle inspection (MPI) technology. This paper proposes an improved DeepLabv3+ semantic segmentation algorithm for automatic defect detection of aviation ferromagnetic parts after MPI. In the network structure, lightweight MobileNetV2 is the backbone feature extraction network. The dense atrous spatial pyramid pooling (DenseASPP) structure is used to strengthen feature extraction. The influence of three different DenseASPP structures on the recognition effect is compared in the experiment. At the same time, the decoder is further optimized. The experimental results show that the Ours-DeepLabv3+ network model can effectively for automatic defect detection of aviation ferromagnetic parts after MPI. The Precision, Recall, F1-score, and intersection over union are 81.64%, 83.12%, 82.37%, and 71.23%, respectively, which are 7.48%, 5.45%, 6.50%, and 10.1% higher than the original DeepLabv3+, and defect detail segmentation is more accurate. Compared with other semantic segmentation algorithms, this method can effectively improve the accuracy of defect detection of aviation ferromagnetic parts and meet the requirements of defect detection.
The twisted baker map
Authors: Saiki Yoshitaka , Takahasi Hiroki , Yorke James A 
Published: February 2023

Abstract
As a model to provide a hands-on, elementary understanding of ‘vortex dynamics’, we introduce a piecewise linear non-invertible map called a twisted baker map. We show that the set of hyperbolic repelling periodic points with complex conjugate eigenvalues and that without complex conjugate eigenvalues are simultaneously dense in the phase space. We also show that these two sets equidistribute with respect to the normalised Lebesgue measure, in spite of a non-uniformity in their Lyapunov exponents.
New linear stability parameter to describe low-β electromagnetic microinstabilities driven by passing electrons in axisymmetric toroidal geometry
Authors: Hardman M R , Parra F I , Patel B S , Roach C M , Ruiz Ruiz J , Barnes M , Dickinson D , Dorland W , Parisi J F , St-Onge D , Wilson H 
Published: February 2023

Abstract
In magnetic confinement fusion devices, the ratio of the plasma pressure to the magnetic field energy, β, can become sufficiently large that electromagnetic microinstabilities become unstable, driving turbulence that distorts or reconnects the equilibrium magnetic field. In this paper, a theory is proposed for electromagnetic, electron-driven linear instabilities that have current layers localised to mode-rational surfaces and binormal wavelengths comparable to the ion gyroradius. The model retains axisymmetric toroidal geometry with arbitrary shaping, and consists of orbit-averaged equations for the mode-rational surface layer, with a ballooning space kinetic matching condition for passing electrons. The matching condition connects the current layer to the large scale electromagnetic fluctuations, and is derived in the limit that β is comparable to the square root of the electron-to-ion-mass ratio. Electromagnetic fluctuations only enter through the matching condition, allowing for the identification of an effective β that includes the effects of equilibrium flux surface shaping. The scaling predictions made by the asymptotic theory are tested with comparisons to results from linear simulations of micro-tearing and electrostatic microinstabilities in MAST discharge #6252, showing excellent agreement. In particular, it is demonstrated that the effective β can explain the dependence of the local micro-tearing mode (MTM) growth rate on the ballooning parameter θ
0–possibly providing a route to optimise local flux surfaces for reduced MTM-driven transport.
Design of step-graded AlGaN buffers for GaN-on-Si heterostructures grown by MOCVD
Authors: Ghosh Saptarsi , Hinz Alexander M , Frentrup Martin , Alam Saiful , Wallis David J , Oliver Rachel A 
Published: February 2023

Abstract
For the growth of low-defect crack-free GaN heterostructures on large-area silicon substrates, compositional grading of AlGaN is a widely adapted buffer technique to restrict the propagation of lattice-mismatch induced defects and balance the thermal expansion mismatch-induced tensile stress. So far, a consolidation of the design strategy of such step-graded buffers has been impaired by the incomplete understanding of the effect of individual buffer design parameters on the mechanical and microstructural properties of the epilayers. Herein, we have analyzed a series of metal-organic chemical vapor deposition grown GaN/graded-AlGaN/AlN/Si heterostructures through in situ curvature measurements and post-growth x-ray diffraction (XRD). Our results reveal that in such epi structures, the GaN layer itself induces more compressive stress than the AlGaN buffer, but the underlying AlGaN layers dictate the magnitude of this stress. Furthermore, for a fixed AlGaN buffer thickness, the mean-stress accumulated during the GaN growth is found to be correlated with its structural properties. Specifically, one µm thick GaN layers that acquire 1.50 GPa or higher compressive mean-stress are seen to possess

20

2
ˉ

1

XRD ω-FWHM values less than 650 arc-sec. Also, the evolution of instantaneous stresses during the growth of the AlGaN layers is found to be a valuable indicator for buffer optimization, and composition difference between successive layers is established as a crucial criterion. The results also show that increasing the total buffer thickness (for a fixed number of steps) or increasing the number of steps (for a fixed total buffer thickness) may not always be beneficial. Irrespective of the buffer thickness, optimized high electron mobility transistor structures show similarly low sheet-resistance (∼350 Ω □)−1 and high mobility (∼2000 cm2 V−1 s −1) at room temperature.
Viscous cosmology in holographic dark energy with Granda–Oliveros cut-off
Authors: Kaur Simran , Singh C P 
Published: February 2023

Abstract
We study the effect of bulk viscosity on holographic dark energy (HDE) with Granda–Oliveros infra-red cut-off. We focus on a generalized form of the bulk viscous coefficient which successfully describes the present-day evolution of the Universe. We observe that the model with bulk viscosity provides an elegant description of the early and late-time evolution of the Universe. We constrain the model through the combined observational data of the Strong Lensing System (SLS), measurements of Hubble parameter, Type Ia supernova data of Pantheon sample and local H
0 measured by SH0ES. Using best-fit values obtained from two different combinations of data, we estimate the present value of Hubble’s constant

H

0

=

71.567

−
0.848

+
1.448

and

H

0

=

69.197

−
1.924

+
1.563

, the deceleration parameter

q

0

=
−

0.535

−
0.016

+
0.016

and

q

0

=
−

0.536

−
0.016

+
0.016

, and the equation of state

ω

0

=
−

0.690

−
0.010

+
0.010

and

ω

0

=
−

0.691

−
0.011

+
0.011

, respectively. The HDE model with bulk viscosity exhibits the phase transition from decelerated epoch to accelerated epoch. A comparison of the model with the standard ΛCDM model is discussed with the statefinder and cosmographic parameters.
Analysis and characterization of CdTe material surface defects
Authors: Bezak M. , Bharthuar S. , Brücken E. , Gädda A. , Golovleva M. , Kalliokoski M. , Kirschenmann S. , Luukka P. , Ott J. 
Published: February 2023

Abstract
To study the impact of various defects associated close to the surface layer of CdTe material, we use scanning laser Transient Current Technique. This gives us an overview of different compositional inhomogeneities, such as dislocations, grain boundaries, and tellurium inclusions. Particularly, reconstructed high resolution spatial images provide a map of different electrically active defects. Each spatial point contains a recording of a current pulse, from which shape we calculate drift times and total collected charge. Charge mobility and charge loss are extracted from current pulses and show the effects of charge trapping and polarization. In addition, we investigate the impact of the ALD alumina-CdTe interface and negative fixed charge trapping using both passivated and non-passivated CdTe crystals.
LHCb VELO fast calibration
Authors: Fernández Prieto A. 
Published: February 2023

Abstract
During the long shutdown 2 of the LHC, the LHCb Experiment was upgraded to a trigger-less system reading out the full detector at 40 MHz bunch crossing rate with all selection algorithms executed in a CPU farm. The upgraded Vertex Locator (VELO) of the LHCb is a hybrid pixel detector read out by the “VeloPix” front-end ASIC with on-chip zero-suppression. This paper describes a novel way of calibrating the VELO detector based on dedicated threshold scan firmware. The firmware is implemented in the control and data acquisition back-end boards of the detector. This threshold scan method has multiple advantages compared with the default one: it is faster as the algorithm was moved from software to firmware, it is more deterministic by minimizing software interruptions and data transfer and it is more precise by reducing noise due to ASIC operation.
LAPPD operation using ToFPETv2 PETSYS ASIC
Authors: Seljak A. , Bračko M. , Dolenec R. , Križan P. , Lozar A. , Pestotnik R. , Korpar S. 
Published: February 2023

Abstract
Single photon sensitive detectors used in high energy physics are, in some applications, required to cover areas the size of several m2, and more specifically in very strong demand with an ever finer imaging and timing capability for Cherenkov Ring Imaging Detector (RICH) configurations. We are evaluating the Large Area Picosecond Photo-detector (LAPPD) produced by INCOM company, as a possible candidate for future RICH detector upgrades. In this work we perform tests on the second generation device, which is capacitively coupled to a custom designed anode back plane, consisting of various pixels and strips varying in size, that allows for connecting various readout systems such as standard laboratory equipment, as well as the TOFPET2 ASIC from PETsys company. Our aim is to evaluate what can be achieved by merging currently available technology, in order to find directions for future developments adapted for specific uses.
Large area hybrid detectors based on Medipix3RX: commissioning and characterization at Sirius beamlines
Authors: Campanelli R.B. , Gomes G.S. , Fernandes M.G. , Mendes L.H. , Rosa L.B. , Reis R.C. , Antonio E.B. , Polli J.M. 
Published: February 2023

Abstract
Hybrid pixel detectors are inherently modular and typically operate at relative low noise levels, while providing high spatial resolution, easing the assembling of large area detectors. This report summarizes the procedures and results regarding the characterization studies performed on the Medipix3RX ASIC based detector, known as PIMEGA, which was developed and is deployed at Sirius synchrotron facility at the Brazilian Synchrotron Light Laboratory. They consist of modular constructions that reach up to 170 × 170 mm2 of active area, with 300 µm thick silicon sensors, and pixel size of 55 × 55 µm2. We investigated the spatial and energy resolutions, structural noise properties, and count-rate linearity up to large fluxes from the synchrotron beamlines. The Modulation Transfer Function presents a considerably slow decay rate as a function of the spatial frequency, reaching 30% at 10.5 lp/mm, for an operation with a threshold setting equivalent to half of the incident energy. We have also found that the energy resolutions of the two highest gain modes are around 15% for 17.5 keV incident photons. In particular, we have found that, for a noise-suppressing set of configurations, the detector presents a dead time of 460 ± 10 ns. Additionally, the pile-up effect leads to a 10% loss of linearity at input fluxes of 2.3 × 105 photons/pixel.s. These results open the possibility for operating these devices with in-depth knowledge of their performance, allowing various scientific experiments, such as X-ray diffraction, computed controlled tomography, and ptychography.
A low noise 2.2 GHz PLL ASIC for the CSR external-target experiment
Authors: Hu Z. , Gao C. , Tian X. , Zhu P. , Liu J. , Wang H. , Chen K. , You B. , Xiao L. , Guo D. , Yang P. , Qiao Y. , Li Y. , Liu X. , Chen Q. , Sun X. , Huang G. , Liu F. 
Published: February 2023

Abstract
This paper presents the design and test results of a low noise Phase Locked Loop (PLL) Application Specific Integrated Circuit (ASIC), which is designed for the data transmission system in a pixel chip for a beam monitor of the Cooling Storage Ring (CSR) external target experiment at HIRFL in China. The proposed PLL consists of a differential ring oscillator, a digital divider, a three-state phase frequency detector, a current charge pump, a second-order loop filter and current mode level buffers. A prototype PLL ASIC has been fabricated in a standard 130 nm CMOS process. The test results show that the frequency of the output clock is about 2.2 GHz with a phase noise of −90 dBc/Hz at a frequency offset of 1 MHz and a root mean square jitter of 1.15 ps. The core circuit of the PLL consumes about 30 mW under the power supply of 1.2 V.
Fast transient infrared detection for time-domain astronomy
Authors: Drago A. , Pace E. , Bini S. , Guidi M.Cestelli , Cioeta F. , Marcelli A. , Bocci V. 
Published: February 2023

Abstract
Multi-messenger astronomy requires the use and development of telescopes and detectors for temporal observations across all the electromagnetic spectrum. The interest of our team is towards time-domain (or longitudinal, in the jargon of storage ring diagnostics) detectors able to make observations over the time rather than transversely by making photographs or spectrographs. The FAIRTEL (Fast InfraRed TELescope) experiment wants to build a very fast detector in the Mid InfraRed (MIR) to be used in time-domain astronomy. The experiment is oriented mainly toward the search of fast astronomical transients in the Galaxy, similarly to what has been observed in different electromagnetic ranges with the discovery of the FRBs (Fast Radio Burst) and the GRBs (Gamma-Ray Burst). In the last years, time-domain astronomy is growing in interest and intends to study events on time scales that can go from hundreds of milliseconds to microseconds and even shorter. The detector proposed by the FAIRTEL experiment, is based on HgCdTe semiconductors and on the experience done in the diagnostics for storage ring developed at DAFNE, the Italian e+/e− circular collider. The detection system design is in progress at the LNF (Laboratori Nazionali di Frascati) of INFN (Istituto Nazionale di Fisica Nucleare) while the telescope will be a standard reflecting type, like a Newtonian, a Cassegrain or a Ritchey–Chrétien telescope. The detection apparatus is under test at the IR synchrotron beamline SINBAD at DAFNE and it is foreseen to be implemented at the OPC (Osservatorio Polifunzionale del Chianti). It should be able to observe events with transients down to the nanosecond. A further development of the project involves the extension from ground-based observations to those by using balloons for scientific studies.