bluuebunny/crossref_metadata_2025_split huggingface dataset:
The influence of different versions of FLUKA and GEANT4 on the calculation of response functions of ionization chambers in clinical proton beams
Authors: Baumann Kilian-Simon , Derksen Larissa , Witt Matthias , Adeberg Sebastian , Zink Klemens 
Published: November 2023

Abstract

Objective. To investigate the influence of different versions of the Monte Carlo codes geant4 and fluka on the calculation of overall response functions f

Q
of air-filled ionization chambers in clinical proton beams. Approach. f

Q
factors were calculated for six plane-parallel and four cylindrical ionization chambers with geant4 and fluka. These factors were compared to already published values that were derived using older versions of these codes. Main results. Differences in f

Q
factors calculated with different versions of the same Monte Carlo code can be up to ∼1%. Especially for geant4, the updated version leads to a more pronounced dependence of f

Q
on proton energy and to smaller f

Q
factors for high energies. Significance. Different versions of the same Monte Carlo code can lead to differences in the calculation of f

Q
factors of up to ∼1% without changing the simulation setup, transport parameters, ionization chamber geometry modeling, or employed physics lists. These findings support the statement that the dominant contributor to the overall uncertainty of Monte Carlo calculated f

Q
factors are type-B uncertainties.
Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy
Authors: Feng Hongying , Holmes Jason M , Vora Sujay A , Stoker Joshua B , Bues Martin , Wong William W , Sio Terence S , Foote Robert L , Patel Samir H , Shen Jiajian , Liu Wei 
Published: November 2023

Abstract

Purpose. To enhance an in-house graphic-processing-unit accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS). Methods and materials. A module to simulate VPs passing through patient-specific aperture blocks was developed and integrated in VPMC based on simulation results of realistic particles (primary protons and their secondaries). To validate the aperture block module, VPMC was first validated by an opensource MC code, MCsquare, in eight water phantom simulations with 3 cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4 cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45 mm water equivalent thickness. Then, VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 c.c. with range of 0.4–43.3 c.c.). Finally, 3 typical patients were selected for robust optimization with aperture blocks using VPMC. Results. In the water phantoms, 3D gamma passing rate (2%/2 mm/10%) between VPMC and MCsquare was 99.71 ± 0.23%. In the patient geometries, 3D gamma passing rates (3%/2 mm/10%) between VPMC/MCsquare and RayStation MC were 97.79 ± 2.21%/97.78 ± 1.97%, respectively. Meanwhile, the calculation time was drastically decreased from 112.45 ± 114.08 s (MCsquare) to 8.20 ± 6.42 s (VPMC) with the same statistical uncertainties of ~0.5%. The robustly optimized plans met all the dose–volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 s and the subsequent on-the-fly ‘trial-and-error’ optimization procedure took only 71.4 s on average for the selected three patients. Conclusion. VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.
Inductive and magnetorheological properties of soft and hard magnetic fillers in elastomers
Authors: Šimić Dino , Lang Andrej , Klüppel Manfred 
Published: November 2023

Abstract
Magnetorheological elastomers are smart materials, that have great potential for many technical applications like intelligent semi-active dampers or energy harvesting applications. We investigate soft- and hard-magnetic filler types in typical technical elastomers under cyclic deformation regarding their influence on the electromagnetic induction and magnetic switching-ability of the compounds. The effect of vulcanization in an external magnetic field is considered leading to anisotropic samples with aligned filler particles. It is found that the soft magnetic fillers show a higher switching-ability compared to hard magnetic fillers in anisotropic samples, which is related to hysteretic and slow magnetization behaviour of hard magnetic fillers. This also leads to a negative switching effect or softening of the samples if the direction of the magnetic field is opposite to that during vulcanization, suggesting rotational motion of the particles in dependence of the outer field. The stress values and mechanical hysteresis are generally higher for the anisotropic samples, both for soft and hard magnetic fillers. This is found for quasistatic and dynamic excitations at different frequencies and can clearly be related to the alignment of particles. Nevertheless, the energy harvesting ability seems to be widely independent of this since no significant different inductive properties are found for isotropic and anisotropic samples. The possibility of a combined magnetorheological and energy harvesting application is discussed.
Detailed analysis of the impact of internal heat leaks on the working properties of cold-carrier energy-emissive harvesters
Authors: Fernández J J 
Published: November 2023

Abstract
We study the working properties of cold-carrier energy-emissive harvesters that have internal heat leaks. We obtain the expressions of their electronic current, open-circuit voltage, chemical potential, power and efficiency using both the Impact-Auger and the Particle-Balance models. For each model we consider two different situations: when CC-EEHs works at constant temperature and when they work receiving a constant input heat flux. We show that heat leaks change all the mentioned properties and that they must be considered in calculations on cold-carrier energy-emissive harvesters. We also discuss how these two working situations are different between them and how considering the losses leads to different results on each one of the two situations.
Effect of film thickness on the electrical and the photocatalytic properties of ZnO nanorods grown by SILAR technique
Authors: Yousra Khadraoui , Guettaf Temam Elhachmi , Saâd Rahmane , Barkat Hadjer 
Published: November 2023

Abstract
In this work, Zinc oxide (ZnO) thin films were synthesised by the successive ionic layer adsorption and reaction (SILAR) technique at various number of cycles (10–50 cycles). The effect of film thickness on the structural properties, surface morphology, optical and electrical properties, and sunlight assisted photocatalytic activities through photocatalytic degradation of Methylene Blue (MB) dye of ZnO thin films were studied. The energy dispersive x-rays (EDX) analysis confirmed the presence Zn and O elements. The x-rays diffraction (XRD) pattern showed the polycrystalline nature of ZnO thin films and the crystallite size increases with film thickness. The SEM images showed that a greater film thickness resulted in the growth of hexagonal nanorods arrays. Atomic force microscopy (AFM) images revealed that the surface roughness increases with film thickness yielding in an enhanced specific surface area. The UV—visible transmission spectra showed that increasing film thickness results in band gap expansion from 3.15 eV to 3.31 eV together with a reduction in optical transmittance. The estimated sheet resistance and resistivity were found to be in the range of 1.34–7.1 Ω sq−1 and 0.09–2.12 ×10–1 Ω.cm. The photocatalytic studies reveal that increasing film thickness leads to an improved photocatalytic efficiency of ZnO films. The enhanced photocatalytic activity of ZnO films is due to the increased surface area and low recombination rate of carriers charges (e−/h+), resulting from band gap expansion.
Superstring cosmology — a complementary review
Authors: Brandenberger Robert 
Published: November 2023

Abstract
In this review, a number of approaches to superstring cosmology which make use of key
features which distinguish string theory from point particle theories are discussed, with
particular emphasis on emergent scenarios. One motivation for the discussion is the
realization that, in order to describe the evolution of the very early universe, it is necessary
to go beyond a conventional effective field theory (EFT) analysis. Some of the conceptual
problems of an EFT analysis will be discussed. The review begins with a summary of the criteria
for a successful early universe scenario, emphasizing that cosmic inflation is not the only
scenario of early universe cosmology which is consistent with current cosmological observations.
Bouncing and emergent scenarios as interesting alternatives are introduced. Some realizations of
these scenarios from superstring theory are reviewed, e.g. String Gas Cosmology, the Pre-Big-Bang
scenario, the Ekpyrotic model, Double Field Theory cosmology and matrix model cosmology. In light
of the difficulties in obtaining cosmic inflation from string theory (at the level of EFT), and
realizing that there are promising examples of alternative early universe scenarios which are
derived from basic principles of superstring theory, one must entertain the possibility that the
cosmology emerging from string theory will not involve an extended period of accelerated
expansion.
Spectro-spatial evolution of the CMB. Part III. Transfer functions, power spectra and Fisher forecasts
Authors: Kite Thomas , Ravenni Andrea , Chluba Jens 
Published: November 2023

Abstract
In this paper, we provide the first computations for the distortion transfer functions of the cosmic microwave background (CMB) in the perturbed Universe, following up on paper I and II in this series. We illustrate the physical effects inherent to the solutions, discussing and demonstrating various limiting cases for the perturbed photon spectrum. We clarify the relationship between distortion transfer functions and the photon spectrum itself, providing the machinery that can then compute constrainable CMB signal power spectra including spectral distortions for single energy injection and decaying particle scenarios. Our results show that the μ × T and y × T power spectra reach levels that can be constrained with current and future CMB experiments without violating existing constraints from COBE/FIRAS. The amplitude of the cross-correlation signal directly depends on the average distortion level, therefore establishing a novel fundamental link between the state of the primordial plasma from redshift 103 ≲ z ≲ 3 × 106 and the frequency-dependent CMB sky. This provides
a new method to constrain average early energy release using CMB imagers. As an example we derive constraints on single energy release and decaying particle scenarios. This shows that LiteBIRD may be able to improve the energy release limits of COBE/FIRAS by up to a factor of ≃ 2.5, while PICO could tighten the constraints by more than one order of magnitude. The signals considered here could furthermore provide a significant challenge to reaching cosmic variance-limited constraints on primordial non-Gaussianity from distortion anisotropy studies. Our work further highlights the immense potential for a synergistic spectroscopic approach to future CMB measurements and analyses.
Neutrino winds on the sky
Authors: Nascimento Caio , Loverde Marilena 
Published: November 2023

Abstract
We develop a first-principles formalism to compute the distortion to the relic neutrino
density field caused by the peculiar motions of large-scale structures. This distortion slows
halos down due to dynamical friction, causes a local anisotropy in the neutrino-CDM
cross-correlation, and reduces the global cross-correlation between neutrinos and CDM. The local
anisotropy in the neutrino-CDM cross-spectrum is imprinted in the three point cross-correlations
of matter and galaxies, or the bispectrum in Fourier space, producing a signal peaking at squeezed
triangle configurations. This bispectrum signature of neutrino masses is not limited by cosmic
variance or potential inaccuracies in the modeling of complicated nonlinear and galaxy formation
physics, and it is not degenerate with the optical depth to reionization. We show that future
surveys have the potential to detect the distortion bispectrum.
Cosmic chronometers with photometry: a new path to H(z)
Authors: Jimenez Raul , Moresco Michele , Verde Licia , Wandelt Benjamin D. 
Published: November 2023

Abstract
We present a proof-of-principle determination of the Hubble parameter H(z) from
photometric data, obtaining a determination at an effective redshift of z = 0.75 (0.65 < z < 0.85)
of H(0.75) = 105.0±7.9(stat)±7.3(sys) km s-1 Mpc-1, with 7.5% statistical and
7% systematic (10% with statistical and systematics combined in quadrature) accuracy. This is
obtained in a cosmology model-independent fashion, but assuming a linear age-redshift relation in
the relevant redshift range, as such, it can be used to constrain arbitrary cosmologies as long as
H(z) can be considered slowly varying over redshift. In particular, we have applied a neural
network, trained on a well-studied spectroscopic sample of 140 objects, to the COSMOS2015
survey to construct a set of 19 thousand near-passively evolving galaxies and build an
age-redshift relation. The Hubble parameter is given by the derivative of the red envelope of the
age-redshift relation. This is the first time the Hubble parameter is determined from photometry
at ≲ 10% accuracy. Accurate H(z) determinations could help shed light on the Hubble
tension; this study shows that photometry, with a reduction of only a factor of two in the
uncertainty, could provide a new perspective on the tension.
A high accuracy reference facility for ongoing comparisons of CO2 in air standards
Authors: Viallon J , Meyer C , Moussay P , Schmidt J , Maxwell S , Arrhen F , Wielgosz R I 
Published: November 2023

Abstract
The design, performance characteristics and validation of a next generation reference facility for carbon dioxide (CO2) in air standards based on manometry is presented. Novel attributes of the facility include automated operation, avoidance of significant pressure corrections for measurements on extracted CO2, fully characterized trapping efficiencies, and reduced measurement uncertainty. Improvements in system performance have been achieved using specific materials, notably Silconert®-treated stainless-steel, providing increased mechanical stability whilst minimizing carbon dioxide adsorption on surfaces, and avoiding use of elastomer O-rings, which would lead to losses of CO2. Full automation of the cryogenic extraction process of CO2 from air has been achieved, avoiding any manual intervention within the temperature stabilized section of the facility, and allowed full characterization and correction for trapping efficiencies and trace water measurement. The facility has been validated across the CO2 in air amount fraction range of (380–800) µmol mol−1 using standards with values traceable to the reference value of the CCQM−K120 (2018) comparison. It was demonstrated to operate with a standard measurement uncertainty of 0.09 µmol mol−1 at 400 µmol mol−1. The automation allows five measurement results per day to be produced with a typical standard deviation of the mean at or below 0.02 µmol mol−1. The facility will be used as a stable reference in the future BIPM.QM−K2 ongoing comparison, to compare consistency of amount fraction values in different CO2 in air standards. The CO2 amount fraction in two ensembles of nine BIPM standards covering the same range will also be measured with the facility to provide their SI-traceable values, and further monitored on a longer time scale. Each ensemble will constitute a CO2 in air scale to be compared with other available scales such as WMO.CO2.X2019 through the BIPM.QM−K5 comparison.
Development of the upgraded single crystal dispersion interferometer (SCDI-U) and its first measurements of the line integrated electron densities in KSTAR during shattered pellet injections
Authors: Lee Dong-Geun , Lee Kwan Chul , Juhn J.-W. , Lee Jae-seok , Kim Jayhyun , Park SooHwan , Lehnen Michael , Park Yong-Hwa , Jeong Jae-Hak , Yim Jaebeom , Ghim Y.-C. 
Published: November 2023

Abstract
Dispersion interferometers (DI) are widely used to measure line integrated electron densities in many fusion devices. A recent development of a heterodyne single crystal DI (SCDI) with a laser wavelength of 1064   nm (Lee et al 2021 Rev. Sci. Instrum.
92 033536) allows an easier and simpler optical setup by using only one, instead of two, nonlinear crystal. It is found that the reported heterodyne SCDI with an acoustic-optical modulator (AOM) has different beam paths between the frequency-shifted, via the AOM, fundamental and second harmonics which act as the reference beams. Such a separation of the reference beams inevitably produces non-removable phase shifts associated with mechanical vibrations, resulting in a reduction of the removing efficiency of the mechanical vibrations that DI systems can provide. By utilizing the fact that the diffraction angle due to the AOM is inversely proportional to the frequency of the laser beam and linearly proportional to an order of the frequency-shift, the SCDI-Upgrade (SCDI-U), which has complete overlap of the optical paths for both probing and reference beams from the laser source to the detectors, is proposed in this work. Its first measurements in KSTAR during shattered pellet injections are reported, and results obtained by the SCDI-U are compared with those from the existing two-color interferometer (TCI) in KSTAR. It is found that the SCDI-U measures the electron density more reliably during such an abrupt and large density change than the TCI does. Qualitative analyses on the effects of different injection schemes of the shattered pellets and possible application of the SCDI-U for ITER are also discussed.
Implementation of dual-energy material decomposition technique in stationary CT baggage scanner withπ-angle sparsity for enhancing threat detection
Authors: Shim Jiyong , Kim Youngjo , Yang Hyesun , Cho Hyosung , Choi Kwangyun 
Published: November 2023

Abstract
Two-dimensional X-ray inspection systems are widely used in aviation security applications; however, they have inherent limitations in recognizing the three-dimensional (3D) shapes of hidden objects. Therefore, there is a growing demand for the implementation of advanced 3D X-ray inspection systems at airports for more accurate detection of threats in luggage and personal belongings. In this study, we designed a new stationary computed tomography (CT) baggage scanner with π-angle sparsity (i.e., 20 pairs of X-ray sources and line detectors were placed within a scan angle of 180°) and compressed sensing (CS)-based reconstruction, and implemented a dual-energy material decomposition (DEMD) technique in the proposed system to separate soft and dense materials of an examined object to enhance threat detection. To validate the efficacy of the proposed approach (CS/180°/P20), we conducted a feasibility study using numerical simulation before its practical implementation. Polychromatic projections were emulated at X-ray tube voltages of 60 and 140 kVp, and DEMD was applied to the projections prior to CT reconstruction. Conventional and dual-energy CT images were reconstructed using both standard filtered-backprojection (FBP) and state-of-the-art CS-based algorithms to compare the image quality. According to our simulation results, the CS-reconstructed images were almost unaffected by the clearly evident streak artifacts on the FBP-reconstructed images because of the use of 20 extreme sparse-view projections, and the image quality of the dual-energy CT images obtained using the proposed CT configuration was similar to that obtained using the conventional CT configuration with 720 dense projections, indicating the efficacy of the proposed approach. Consequently, high-quality dual-energy CT images of soft and dense materials were successfully obtained using the proposed stationary CT configuration.
Development of the Thomson scattering measurement system for cascade arc device with indirectly heated hollow cathode
Authors: Yamasaki K. , Okuda K. , Kono J. , Saito A. , Mori D. , Suzuki R. , Kambara Y. , Hamada R. , Namba S. , Tomita K. , Pan Y. , Tamura N. , Suzuki C. , Okuno H. 
Published: November 2023

Abstract
We have developed a Thomson scattering measurement system for the cascade arc discharge
device designed for the plasma window (PW) application study. The PW is one of the plasma
application techniques that sustain the steep pressure gradient between high pressure (10–100 kPa)
and a vacuum environment due to the thermal energy of the plasma. Since the plasma thermal energy
is the essential parameter for the pressure separation capability of PW, we installed the Thomson
scattering measurement system to observe the electron density and temperature within the anode and
cathode of the PW for the detailed analysis of the pressure separation capability. The
frequency-doubled Nd:YAG laser (532 nm, 200 mJ, 8 ns) was employed for the probe laser. The
scattered light was fed to the triple grating spectrometer. The notch filter between the first
and second grating eliminated the stray light, realizing a sufficiently high signal-to-noise
ratio. The Thomson scattering measurement system successfully obtained the electron density and
temperature of the cascade arc plasma at 20 mm downstream from the tip of the cathode. The
installed system successfully obtained the Thomson scattering spectrum and showed that the
electron density increased from 2 × 1019 m-3 to 7 × 1019
m-3 with the discharge power, while the electron temperature was almost constant at about 2 eV. The obtained data successfully contributed to the study of the pressure separation capability
of the PW.
Discrepant trends in global land-surface and air temperatures controlled by vegetation biophysical feedbacks
Authors: Kan Fei , Lian Xu , Cui Jiangpeng , Chen Anping , Mao Jiafu , He Mingzhu , Xu Hao , Piao Shilong 
Published: November 2023

Abstract
Satellite-based land surface temperature (Ts) with continuous global coverage is increasingly used as a complementary measure for air temperature (Ta), yet whether they observe similar temporal trends remains unknown. Here, we systematically analyzed the trend of the difference between satellite-based Ts and station-based Ta (Ts–Ta) over 2003–2022. We found the global land warming rate inffered from Ts was on average 42.6% slower than that from Ta (Ts–Ta trend: −0.011 °C yr−1, p = 0.06) during daytime of summer. This slower Ts-based warming was attributed to recent Earth greening, which effectively cooled canopy surface through enhancing evapotranspiration and turbulent heat transfer. However, Ts showed faster warming than Ta during summer nighttime (0.015 °C yr−1, p < 0.01), winter daytime (0.0069 °C yr−1, p = 0.08) and winter nighttime (0.0042 °C yr−1, p = 0.16), when vegetation activity is limited by temperature and solar radiation. Our results indicate potential biases in assessments of atmospheric warming and the vegetation-air temperature feedbacks using satellite-observed surface temperature proxies.