bluuebunny/crossref_metadata_2025 huggingface dataset:
Redefining the Inclusion Criteria for Successful Steindler Flexorplasty Based on the Outcomes of a Case Series in Eight Patients
Authors: Gatskiy Alexander A. , Tretyak Ihor B. , Bahm Jörg , Tsymbaliuk Vitaliy I. , Tsymbaliuk Yaroslav V.
Published: October 2023

Background (rationale) Steindler flexorplasty (SF) is aimed at restoring independent elbow flexion in the late stages of dysfunction of the primary elbow flexors. Selection criteria for successful SF have been defined.

Objectives The purpose of this study was to redefine the inclusion criteria for successful SF based on functional outcomes.

Methods Eight patients received SF after an average of 50.8 months after injury or dysfunction. Three patients (37.5%) met all five Al-Qattan inclusion criteria (AQIC), and another five patients (62.5%) met four or less AQIC. Patients were followed up for at least 9 months, and the maximum range of active elbow flexion (REF) was measured. Functional results of SF were assessed using the Al-Qattan scale (in accordance with Al-Qattan's scale).

Results The mean maximum REF was 100 degrees (70 to 140 degrees). Five patients reached REF greater than 100 degrees. One patient had a poor outcome, two patients (25%) had a fair outcome, three patients (37.5%) had a good outcome, and two patients (25%) had an excellent outcome of SF on the Al-Qattan scale. The impact of each AQIC on functional outcome has been critically reviewed from a biomechanical point of view.

Conclusions The sufficient number of inclusion criteria required for successful SF can be reduced from five (according to AQIC) to two; Normal or near-normal function (M4 or greater on the MRC scale) of the muscles of the flexor-pronator mass should be considered an obligatory inclusion criterion, while primary wrist extensors may be considered an optional inclusion criterion.
Breaking silence and constructing intersubjectivity: ways of solving the conflicts in The Woman Warrior and The Kitchen God’s Wife
Authors: Guo Haixia
Published: October 2023

“Silence” is a form of “being invisible”. It occupies an important position in “non-native” women writers’ works in the United States. While focusing on the silence in Maxine Hong Kingston’s The Woman Warrior: Memoirs of a Girlhood Among Ghosts and Amy Tan’s The Kitchen God’s Wife, this study attempts to explore and reveal the conflicts hidden behind silence: the conflict between genders, the conflict between races, and the conflict between Chinese culture and American one. In The Woman Warrior, the narrator’s father and mother’s silence about and prohibition of the mention of the no-name aunt are reflections of the ideology of the patriarchal world; the conflict between races is revealed in the silence of the narrator in American schools, and in her whisper before the bosses who are racists. In The Kitchen God’s Wife, Winnie’s secret about her past and her silence about her husband’s wrong doings show her contempt and disillusionment of the whole patriarchal society. The obstruction in the communication between the narrator and her mother in The Woman Warrior and the silence between Winnie and her daughter, Pearl in The Kitchen God’s Wife are not only a problem of generation gap, but more importantly, the great differences between two cultures: mother represents Chinese culture while daughter the American one. The analysis shows that in order to solve the conflicts, women characters not only have to break silence, but also assert their subjectivity and acknowledge both the self and the other. Relying on Jessica Benjamin’s theory on intersubjectivity, this paper asserts that equal and successful communication between genders, races and cultures can be achieved through the construction of intersubjectivity.
Electron population dynamics in resonant non-linear x-ray absorption in nickel at a free-electron laser
Authors: Engel Robin Y. , Alexander Oliver , Atak Kaan , Bovensiepen Uwe , Buck Jens , Carley Robert , Cascella Michele , Chardonnet Valentin , Chiuzbaian Gheorghe Sorin , David Christian , Döring Florian , Eschenlohr Andrea , Gerasimova Natalia , Groot Frank de , Guyader Loïc Le , Humphries Oliver S. , Izquierdo Manuel , Jal Emmanuelle , Kubec Adam , Laarmann Tim , Lambert Charles-Henri , Lüning Jan , Marangos Jonathan P. , Mercadier Laurent , Mercurio Giuseppe , Miedema Piter S. , Ollefs Katharina , Pfau Bastian , Rösner Benedikt , Rossnagel Kai , Rothenbach Nico , Scherz Andreas , Schlappa Justine , Scholz Markus , Schunck Jan O. , Setoodehnia Kiana , Stamm Christian , Techert Simone , Vinko Sam M. , Wende Heiko , Yaroslavtsev Alexander A. , Yin Zhong , Beye Martin
Published: October 2023

Free-electron lasers provide bright, ultrashort, and monochromatic x-ray pulses, enabling novel spectroscopic measurements not only with femtosecond temporal resolution: The high fluence of their x-ray pulses can also easily enter the regime of the non-linear x-ray–matter interaction. Entering this regime necessitates a rigorous analysis and reliable prediction of the relevant non-linear processes for future experiment designs. Here, we show non-linear changes in the L3-edge absorption of metallic nickel thin films, measured with fluences up to 60 J/cm2. We present a simple but predictive rate model that quantitatively describes spectral changes based on the evolution of electronic populations within the pulse duration. Despite its simplicity, the model reaches good agreement with experimental results over more than three orders of magnitude in fluence, while providing a straightforward understanding of the interplay of physical processes driving the non-linear changes. Our findings provide important insights for the design and evaluation of future high-fluence free-electron laser experiments and contribute to the understanding of non-linear electron dynamics in x-ray absorption processes in solids at the femtosecond timescale.
A multiscale 3D hotspot-rich nanostructured substrate for biomolecular detection of SARS-CoV-2
Authors: Sahoo Smruti R. , Huang Chun-Ta , Tsai Kunju , Wang Gou-Jen , Chang Cheng-Chung
Published: October 2023

The current fabrication methods of surface-enhanced Raman scattering (SERS) chips used for biological detection mostly require antibodies conjugated on nanostructured metals or additionally connected to a reporter, which leads to complicated fabrication processes and increases the cost of these chips. More importantly, only a single-layer (2D) signal source is generated on the substrate of the chip, resulting in poor sensitivity. Herein, we constructed a single-component, multiscale, three-dimensional SERS (M3D-SERS) substrate from silver nanowires (AgNWs) packing. According to our results, the Raman enhancement effect of the M3D-SERS substrate was related to the degree of AgNWs stacking along the z axis. In addition, the light source-dependent plasmonic partition and hotspot formation of the M3D-SERS substrate were evaluated by the finite integration technique to prove that M3D-SERS offers advantages, with isotropic localized surface plasmon resonance as well as homogeneous hotspot distribution, for SERS over its 1D and 2D counterparts. Experimentally, the optimal construction of the M3D-SERS chip was explored and established based on the Raman signal enhancement of bovine serum albumin, and consequently, the efficiency of the M3D-SERS chip in detecting SARS-CoV-2-related biomolecules was investigated based on the detection superiority to biomolecules. This study demonstrates a simple, label-free, pre-treatment-free potential biosensor technology that can be used in healthcare units. Furthermore, in combination with a suitable laser light source, this technology can be applied for efficient detection in point-of-care tests with a handheld spectrometer.
Simultaneously enhancing the tensile strength and ductility of high entropy alloys by nanoscale precipitates/fillers
Authors: Liu Ping , Chen Shuai , Pei Qing-Xiang , Aitken Zachary H. , Li Wanghui , Zhang Yong-Wei
Published: October 2023

High entropy alloys (HEAs) in the solid solution (SS) phase have attracted much attention due to their novel strengthening mechanisms. Recent studies have shown that introducing nanoscale precipitates/fillers can further strengthen the SS HEAs. In this work, we performed large-scale molecular dynamics simulations of AlxCoCuFeNi HEAs filled with randomly distributed AlNi3 nanoparticles. The effects of AlNi3 particle size and volume fraction, the chemical composition of the HEA matrix, and temperature on the mechanical properties, deformation, and failure behavior of the composite are systematically investigated. Our simulations show that, remarkably, the AlNi3 nanoparticles can simultaneously enhance the ultimate tensile strength and ultimate tensile strain of the composite. The underlying mechanism is that the AlNi3 nanoparticles greatly suppressed the phase change and dislocation appearance in the HEA matrix, resulting in a delayed material failure during the deformation. We also find that Young’s modulus, ultimate tensile strength, and ultimate tensile strain follow the lower-bound of the rule of mixtures and further present the underlying reason for this lower-bound relation. The present work not only provides insights into the mechanical properties, deformation, and failure behavior of AlNi3 nanoparticle-reinforced AlxCoCuFeNi HEAs but is also useful for guiding the rational design of HEAs for engineering applications.
A forward modeling approach to analyzing galaxy clustering with S
im
BIG
Authors: Hahn ChangHoon , Eickenberg Michael , Ho Shirley , Hou Jiamin , Lemos Pablo , Massara Elena , Modi Chirag , Moradinezhad Dizgah Azadeh , Blancard Bruno Régaldo-Saint , Abidi Muntazir M.
Published: October 2023

We present cosmological constraints from a simulation-based inference (SBI) analysis of galaxy clustering from the S
im
BIG forward modeling framework. S
im
BIG leverages the predictive power of high-fidelity simulations and provides an inference framework that can extract cosmological information on small nonlinear scales. In this work, we apply S
im
BIG to the Baryon Oscillation Spectroscopic Survey (BOSS) CMASS galaxy sample and analyze the power spectrum,

P
ℓ

(
k
)

, to

k
max

=
0.5

h
/
Mpc

. We construct 20,000 simulated galaxy samples using our forward model, which is based on 2,000 high-resolution Q
uijote

N

-body simulations and includes detailed survey realism for a more complete treatment of observational systematics. We then conduct SBI by training normalizing flows using the simulated samples and infer the posterior distribution of

Λ

CDM cosmological parameters:

Ω
m

,

Ω
b

,
h
,

n
s

,

σ
8

. We derive significant constraints on

Ω
m

and

σ
8

, which are consistent with previous works. Our constraint on

σ
8

is 27% more precise than standard

P
ℓ

analyses because we exploit additional cosmological information on nonlinear scales beyond the limit of current analytic models,

k
>
0.25

h
/
Mpc

. This improvement is equivalent to the statistical gain expected from a standard

P
ℓ

analysis of galaxy sample

∼

60% larger than CMASS. While we focus on

P
ℓ

in this work for validation and comparison to the literature, S
im
BIG provides a framework for analyzing galaxy clustering using any summary statistic. We expect further improvements on cosmological constraints from subsequent S
im
BIG analyses of summary statistics beyond

P
ℓ

.
Activity of estrogen receptor β expressing neurons in the medial amygdala regulates preference toward receptive females in male mice
Authors: Takenawa Satoshi , Nagasawa Yutaro , Go Kim , Chérasse Yoan , Mizuno Seiya , Sano Kazuhiro , Ogawa Sonoko
Published: October 2023

The processing of information regarding the sex and reproductive state of conspecific individuals is critical for successful reproduction and survival in males. Generally, male mice exhibit a preference toward the odor of sexually receptive (RF) over nonreceptive females (XF) or gonadally intact males (IM). Previous studies suggested the involvement of estrogen receptor beta (ERβ) expressed in the medial amygdala (MeA) in male preference toward RF. To further delineate the role played by ERβ in the MeA in the neuronal network regulating male preference, we developed a new ERβ-iCre mouse line using the CRISPR-Cas9 system. Fiber photometry Ca
2+
imaging revealed that ERβ-expressing neurons in the postero-dorsal part of the MeA (MeApd-ERβ
+
neurons) were more active during social investigation toward RF compared to copresented XF or IM mice in a preference test. Chemogenetic inhibition of MeApd-ERβ
+
neuronal activity abolished a preference to RF in “RF vs. XF,
”
but not “RF vs. IM,
”
tests. Analysis with cre-dependent retrograde tracing viral vectors identified the principal part of the bed nucleus of stria terminalis (BNSTp) as a primary projection site of MeApd-ERβ
+
neurons. Fiber photometry recording in the BNSTp during a preference test revealed that chemogenetic inhibition of MeApd-ERβ
+
neurons abolished differential neuronal activity of BNSTp cells as well as a preference to RF against XF but not against IM mice. Collectively, these findings demonstrate for the first time that MeApd-ERβ
+
neuronal activity is required for expression of receptivity-based preference (i.e., RF vs. XF) but not sex-based preference (i.e., RF vs. IM) in male mice.
Preparation of porous ceramsite from municipal sludge and its structure characteristics
Authors: Meng Junping , Cui Zhenxiao , Srinivasakannan Chandrasekar , Duan Xinhui , Liang Jinsheng , Tian Guangyan , Yang Zhiling , Wei Xiangying
Published: October 2023

In this paper, the municipal sludge was used as the main raw material to prepare a kind of porous ceramsite. The porous ceramsite composition of 50 wt-% of municipal sludge, 10 wt-% of municipal solid waste incineration bottom ash, 45 wt-% of waste glass powders, sintering temperature of 900°C and holding duration of 30 min. The best of the ceramsite synthesised had 1-h water absorption capacity of 51.53%, apparent porosity of 64.14% and pore volume 0.671 mL g−1. During the sintering process, the waste glass powders generated a large amount of liquid phase, wrapt the gas produced by organic matter, and formed a porous structure inside the ceramic particles. At the same time, the silica and aluminium were combined to form Kyanite, which constitutes the basic skeleton of the ceramic particles showing a certain strength. Besides, silicon oxide and calcium silicate generated Wollastonite improving the corrosion resistance of ceramic particles as well. The adsorption capacity of the prepared porous ceramsite modified by acid combined with sodium citrate was 3.1 mg g−1 using the prepared porous ceramsite as substrate. The adsorption kinetics of ammonia nitrogen by porous ceramics conforms to the quasi-second-order kinetic model, and the adsorption isotherm model conforms to the Langmuir model. The findings lay a theoretical foundation for the integration of resource utilisation of solid waste and later application.
Investigation of test methods for QC in dual-energy based contrast-enhanced digital mammography systems: II. Artefacts/uniformity, exposure time and phantom-based dosimetry
Authors: Marshall N W , Cockmartin L , Bosmans H
Published: October 2023

Part II of this study describes constancy tests for artefacts and image uniformity, exposure time, and phantom-based dosimetry; these are applied to four mammography systems equipped with contrast enhanced mammography (CEM) capability. Artefacts were tested using a breast phantom that simulated breast shape and thickness change at the breast edge. Image uniformity was assessed using rectangular poly(methyl)methacrylate PMMA plates at phantom thicknesses of 20, 40 and 60 mm, for the low energy (LE), high energy (HE) images and the recombined CEM image. Uniformity of signal and of the signal to noise ratio was quantified. To estimate CEM exposure times, breast simulating blocks were imaged in automatic exposure mode. The resulting x-ray technique factors were then set manually and exposure time for LE and HE images and total CEM acquisition time was measured with a multimeter. Mean glandular dose (MGD) was assessed as a function of simulated breast thickness using three different phantom compositions: (i) glandular and adipose breast tissue simulating blocks combined to give glandularity values that were typical of those in a screening population, as thickness was changed (ii) PMMA sheets combined with polyethylene blocks (iii) PMMA sheets with spacers. Image uniformity was superior for LE compared to HE images. Two systems did not generate recombined images for the uniformity test when the detector was fully covered. Acquisition time for a CEM image pair for a 60 mm thick breast equivalent phantom ranged from 3.4 to 10.3 s. Phantom composition did not have a strong influence on MGD, with differences generally smaller than 10%. MGD for the HE images was lower than for the LE images, by a factor of between 1.3 and 4.0, depending on system and simulated breast thickness. When combined with the iodine signal assessment in part I, these tests provide a comprehensive assessment of CEM system imaging performance.
Shoot-through proton FLASH irradiation lowers linear energy transfer in organs at risk for neurological tumors and is robust against density variations
Authors: Kneepkens Esther , Wolfs Cecile , Wanders Roel-Germ , Traneus Erik , Eekers Danielle , Verhaegen Frank
Published: October 2023

Objective. The goal of the study was to test the hypothesis that shoot-through FLASH proton beams would lead to lower dose-averaged LET (LETD) values in critical organs, while providing at least equal normal tissue sparing as clinical proton therapy plans. Approach. For five neurological tumor patients, pencil beam scanning (PBS) shoot-through plans were made, using the maximum energy of 227 MeV and assuming a hypothetical FLASH protective factor (FPF) of 1.5. The effect of different FPF ranging from 1.2 to 1.8 on the clinical goals were also considered. LETD was calculated for the clinical plan and the shoot-through plan, applying a 2 Gy total dose threshold (RayStation 8 A/9B and 9A-IonRPG). Robust evaluation was performed considering density uncertainty (±3% throughout entire volume). Main results. Clinical plans showed large LETD variations compared to shoot-through plans and the maximum LETD in OAR is 1.2–8 times lower for the latter. Although less conformal, shoot-through plans met the same clinical goals as the clinical plans, for FLASH protection factors above 1.4. The FLASH shoot-through plans were more robust to density uncertainties with a maximum OAR D2% increase of 0.6 Gy versus 5.7 Gy in the clinical plans. Significance. Shoot-through proton FLASH beams avoid uncertainties in LETD distributions and proton range, provide adequate target coverage, meet planning constraints and are robust to density variations.
A systematic approach for calibrating a Monte Carlo code to a treatment planning system for obtaining dose, LET, variable proton RBE and out-of-field dose
Authors: Tjelta Johannes , Fjæra Lars Fredrik , Ytre-Hauge Kristian Smeland , Boer Camilla Grindeland , Stokkevåg Camilla Hanquist
Published: October 2023

Objective. While integration of variable relative biological effectiveness (RBE) has not reached full clinical implementation, the importance of having the ability to recalculate proton treatment plans in a flexible, dedicated Monte Carlo (MC) code cannot be understated . Here we provide a step-wise method for calibrating dose from a MC code to a treatment planning system (TPS), to obtain required parameters for calculating linear energy transfer (LET), variable RBE and in general enabling clinical realistic research studies beyond the capabilities of a TPS. Approach. Initially, Pristine Bragg peaks (PBP) were calculated in both the Eclipse TPS and the FLUKA MC code. A rearranged Bortfeld energy-range relation was applied to the initial energy of the beam to fine-tune the range of the MC code at 80% dose level distal to the PBP. The energy spread was adapted by dividing the TPS range by the MC range for dose level 80%–20% distal to the PBP. Density and relative proton stopping power were adjusted by comparing the TPS and MC for different Hounsfield units. To find the relationship of dose per primary particle from the MC to dose per monitor unit in the TPS, integration was applied to the area of the Bragg curve. The calibration was validated for spread-out Bragg peaks (SOBP) in water and patient treatment plans. Following the validation, variable RBE were calculated using established models. Main results. The PBPs ranges were within ±

0.3

mm threshold, and a maximum of 5.5% difference for the SOBPs was observed. The patient validation showed excellent dose agreement between the TPS and MC, with the greatest differences for the lung tumor patient. Significance. A procedure for calibrating a MC code to a TPS was developed and validated. The procedure enables MC-based calculation of dose, LET, variable RBE, advanced (secondary) particle tracking and more from treatment plans.
Tuning magnetic and optical properties in As–Ge (Si) co-doped MoS2 monolayer by defect-defect interaction
Authors: Zhang Sifan , Li Jin , Fu Zhentao , Deng Jiao , Hao Guolin , He Chaoyu , Ouyang Tao , Tang Chao , Zhong Jianxin
Published: October 2023

Modulating magnetic properties in monolayer MoS2 is important for the applications in spintronics and magnetism devices. In this work, we have studied the electronic, magnetic and optical properties of co-doped monolayer MoS2 with As–Ge (Si) doping on S surfaces through the first-principle calculations. Our results show that the magnetic properties of monolayer MoS2 can be tuned effectively by the distance of co-doped atoms. The projected density of state and the charge transfer demonstrate the interaction and superexchange coupling between As and Ge (Si) atoms are the key factor in the magnetic properties of co-doped structures. Furthermore, it is found that co-doping can also induce spin-polarized optical properties in low-energy region, which makes the co-doped MoS2 attractive candidates for spin-polarized photoelectric device applications.
The azimuth manipulation of nonlocal photorefractive spatial solitons
Authors: Wang S-F
Published: October 2023

By reducing the Helmholtz equation in the form of complex vector, a new non-local Kerr media model is obtained. The solutions of vector multi-pole mode solitons and vortex solitons are derived and analyzed by using the variational method. Then, the spatial modulation nonlinearity and orbital azimuth modulation (OAM) of the model are studied by using the rotation equation. The results show that when the different modulated parameters are selected, the different rotation structures of vector multi-pole mode solitons or vortex solitons can be formed and it has a certain significance for the shape shaping and control of the soliton.
Enhancement of the structural, optical, and dispersion performance of polyvinyl alcohol via coronene additive for optoelectronic applications
Authors: Al-Muntaser A A , Alzahrani Eman , Abo-Dief Hala M , Saeed Abdu , Al-Marhaby F A , Al-Harthi Amani M , Tarabiah A E
Published: October 2023

Composite films made of polyvinyl alcohol (PVA) filled with various coronene concentrations were fabricated via the solution casting method. Several characterization techniques were used to examine the prepared samples. The x-ray diffraction study shows decreasing semi-crystalline properties in PVA/coronene composites with increasing coronene levels, thereby improving charge carrier mobility and enhancing conductivity. The alterations in the chemical functional groups of the PVA/coronene composites were explored using Fourier-transform infrared spectroscopy (FTIR). The impact of coronene molecules on the optical characteristics of PVA was investigated in the spectral ranges of 190-2500 nm. PVA/coronene composite exhibits higher UV blocking in the 190-400 nm wavelength range, suitable for UV notch filters like laser blocking filters. By increasing the coronene filling ratio from 0 wt% to 3 wt%, both the indirect and direct optical band-gap of PVA films decreased from 5.19 eV and 5.77 eV to 3.85 eV and 5.18 eV, respectively. The single oscillator model (Wemple-DiDomenico) was used to explain the refractive index dispersion region. The extracted values of dispersion energy (Ed), oscillator energy (Eo), dielectric constant at infinite frequency (ε
∞), and lattice dielectric constant (ε
L) of PVA/coronene composite samples increased from 0.78 eV, 2.41 eV, 1.32 and 1.41 to 13.44 eV, 12.22 eV 2.10 and 2.13, respectively. These changes in dispersion parameters are due to cross-linking between the PVA polymeric matrix and the coronene. As a result of these improvements, PVA/coronene films could be applied to flexible packaging applications and optoelectronic devices like solar cells or light-emitting diodes.
Mass transport and thermal properties of liquid (melting to boiling point) tungsten: a molecular dynamics simulations
Authors: Gohil D R , Shankar A , Bhatt N K
Published: October 2023

We present molecular dynamics simulation to obtain melting point, structural and atomic transport properties of liquid tungsten. We considered the second-neighbor extended Finnis-Sinclair (EFS) potential as an effective interaction. We find melting temperature (T
M) and density in agreement with the reported values. EFS potential gives accurate information for structure factor S(q), pair correlation function g(r), and transport coefficients like self-diffusion coefficient and viscosity upto ∼1.5T
M. Large viscosity proposes the rheological nature of liquid W. The self-diffusion coefficient follows the Arrhenius law giving the activation energy 1.22 eV. We find ’shoulder’ in the second peak of S(q), which disappears with temperatures. This characteristic is attributed to the high density and clustering of W-atoms at the near-neighbor distance. The asymmetric first peak in g(r) and shoulder in S(q) proposes that the liquid W exhibits non-normal metallic behaviour. Discrepancy observed in caloric properties for temperature >6000 K is also discussed. We propose that the ’softness’ and broad dip in EFS potential are responsible for these discrepancies, and necessitate the inclusion of angular forces. The single particle correlation is discussed in terms of the velocity autocorrelation function and the long-wavelength limit of S(q) is utilized to derive adiabatic sound velocity in confirmation with reported results.
PRIYA: a new suite of Lyman-α forest simulations for cosmology
Authors: Bird Simeon , Fernandez Martin , Ho Ming-Feng , Qezlou Mahdi , Monadi Reza , Ni Yueying , Chen Nianyi , Croft Rupert , Di Matteo Tiziana
Published: October 2023

We present the PRIYA suite of cosmological simulations, based on the code and hydrodynamic model of the ASTRID simulation, and designed for cosmological analyses of the Lyman-αforest. Our simulation suite spans a 9-dimensional parameter space, including 4 cosmological parameters and 5 astrophysical/thermal parameters. We have run 48 low fidelity simulations with 15363particles in a 120 Mpc/h box and 3 high fidelity simulations with 30723particles in a 120 Mpc/h box. All our simulations include a full physics model for galaxy formation, including supernova and AGN feedback, and thus also contain a realistic population of DLAs. We advance on earlier simulations suites by larger particle loads, by incorporating new physical models for patchy hydrogen and helium reionization, and by self-consistently incorporating a model for AGN feedback. We show that patchy helium reionization imprints an excess in the 1D flux power spectrum on large scales, which may allow future measurements of helium reionization bubble sizes. Simulation parameters are chosen based on a Latin hypercube design and a Gaussian process is used to interpolate to arbitrary parameter combinations. We build a multi-fidelity emulator for the 1D flux power spectrum and the mean IGM temperature. We show that our final interpolation error is < 1% and that our simulations produce a flux power spectrum converged at the percent level forz= 5.4–2.2. Our simulation suite will be used to interpret Lyman-αforest 1D flux power spectra from SDSS and future DESI data releases.
News from the Swampland — constraining string theory with astrophysics and cosmology
Authors: Schöneberg Nils , Vacher Léo , Dias J.D.F. , Carvalho Martim M.C.D. , Martins C.J.A.P.
Published: October 2023

Our current best guess for a unified theory of gravitation and quantum field theory (string theory) generically predicts a set of requirements for a consistently quantized theory, the Swampland criteria. Refined versions of these criteria have recently been shown to be in mild tension with cosmological observations. We summarize the status of the current impact of and constraints on the Swampland conjectures from cosmology, and subject a variety of dark energy quintessence models to recently released cosmological datasets. We find that instead of tightening the tension, the new data allows for slightly more freedom in the Swampland criteria. We further demonstrate that if there is no theoretical argument made to prevent interactions of the moduli fields with the electromagnetic sector, a novel fine-tuning argument arises from the extremely tight current constraints on such interactions. Finally, we conclude with a cautionary tale on model-independent reconstructions of the Swampland criteria from expansion rate data.
The VENUS imaging beamline at the Spallation Neutron Source: layout, expected performance and status of the construction project
Authors: Bilheux H Z , Bilheux J C , Hanks R A , Byrd A , Jones A , Skorpenske H , Donnelly M E , Mangus R , Conner D , Lessard T L , Venkatakrishnan S , Tang S , Thomasson T , Keener W S , Rennich G
Published: October 2023

Located at the Spallation Neutron Source, VENUS is an instrument optimized for wavelength-dependent neutron imaging techniques, namely Bragg edge and resonance imaging, across a broad range of neutron energies (from meV to hundreds of eV). The VENUS construction project started in Fall 2018, establishing a conceptual design of the major components and timeline for purchasing, testing, and installation. Completion of the VENUS instrument is anticipated late 2024. This instrument comprises components such as a set of boron carbide apertures designed for both thermal/cold and epithermal neutrons, a suite of choppers (T0 and single disks), beam collimators, and a cadmium filter. The time-of-flight detector at VENUS will be the micro-channel-plate Timepix detector and will be positioned 25 m away from the source. This manuscript describes the instrument general layout, explains the choice of the moderator, and specifies the VENUS key capabilities. It also provides the status of the construction project with installed components. Discussions about software development are also presented.
Neutron imaging software tools at the Oak Ridge National Laboratory
Authors: Bilheux Jean C , Bilheux Hassina Z , Zhang Yuxuan , Crompton Rich , Bedynek Matthew J , Zhang Chen , Parker Peter , Granroth Garrett , Lin Jiao , Lumsden Ian , Sebold Simon , Neuwirth Tobias
Published: October 2023

Over the past decade, Oak Ridge National Laboratory developed neutron capabilities at both the High Flux Isotope Reactor and the Spallation Neutron Source. A broad scientific portfolio has flourished at both facilities such that a new facility named VENUS is currently under construction at the Spallation Neutron Source. With a large range of applications, comes a broad range of user expertise regarding data processing, analysis, and visualization. Our team has developed and implemented a suite of tools to respond to all user needs. These tools span from data reduction, normalization, general tools such as organization of data folders, pre-processing of data, etc., to strain mapping, neutron grating interferometry, and advanced reconstruction algorithms for computed tomography. This manuscript provides an overview of some of the aforementioned tools.
Development of an areal density imaging for boron and other elements
Authors: Tsuchikawa Y , Kai T , Abe Y , Oikawa K , Parker J D , Shinohara T , Sato I
Published: October 2023

Boron areal densities in pure boron samples were determined using energy-resolved neutron measurements. For non-destructive measurement of boron content, the neutron-energy spectrum was measured with prompt γ-ray activation analysis. It was confirmed that the areal density of samples could be measured with 1% to 10% accuracy for high boron content by neutron energy spectrum analysis. The viability of this analysis is also discussed compared with the traditional quantitative analysis.
A new method to obtain the crystallographic texture of polycrystalline materials in Bragg edge imaging experiments
Authors: Alvarez M A Vicente , Malamud Florencia
Published: October 2023

In polycrystalline materials, the shape and height of Bragg edges observed in wavelength resolved neutron transmission experiments depend on the crystallographic texture. Previous works have proved the capacity of actual models to predict the transmission spectra once the texture of the material is known. In this work, we summarize the recent advances done trying to obtain information of the texture from the experimental transmission data. The basis of this method resides in a compact expression of the coherent elastic cross section in terms of the Fourier coefficients of the orientation distribution function, which describes the crystallographic texture. The validity of this method is restricted to the applicability of the kinematic approximation of diffraction (polycrystalline materials with grain sizes below 10μm) and to materials with spatially uniform texture.
Measurements of gas-liquid two-phase flow dynamics using high-speed neutron imaging
Authors: Ito D , Odaira N , Ito K , Saito Y , Kurita K , Iikura H
Published: October 2023

Gas-liquid two-phase flow appears in many heat-exchanging devices. The two-phase flow dynamics should be clarified to understand the phenomena in such devices. Although many measurement techniques have been applied to two-phase flow experiments, measuring the gas-liquid interfacial structure is difficult, which changes temporally and spatially. In this study, high-speed neutron imaging is used to measure two-phase flow dynamics, and the accuracy of the void fraction measurement is investigated. In high-speed neutron imaging, image blurring and distortion occur due to light and object motion intensifying. As a result, the quantitative accuracy might decrease. So, the rotating stainless-steel calibration disk, which simulates the bubble behavior in water, is observed by high-speed neutron imaging. Several noise reduction filters are tested to remove the blur and noise in the acquired images. Finally, the air-water two-phase flow is visualized by high-speed neutron imaging, and noise filtering is applied.
Temperature distribution during welding measured by neutron imaging
Authors: Jamro R. , Mente T. , Kardjilov N. , Markötter H. , Al-Falahat Ala’A. M. , Woracek R. , Manke I. , Griesche A.
Published: October 2023

This study was carried out to investigate the neutron transmission signal as a function of sample temperature during a welding process. A theoretical description that includes the Debye-Waller factor was used to describe the temperature influence on the neutron cross-sections. Neutron imaging using a monochromatic beam helps to observe transmission variations related to the material temperature. In-situ neutron imaging of welding experiments show the distribution of the temperature in bulk steel samples. The performed finite element modelling of expected temperature distributions shows good agreement with the obtained experimental data.
Bragg edge imaging characterization of multi-material laser powder-bed fusion specimens
Authors: Malamud F , Polatidis E , Busi M , Capek J. , Deillon L , Bambach M , Zehnder P , Losko A , Strobl M
Published: October 2023

Multi-material laser powder-bed fusion (M2LPBF) is a novel additive manufacturing approach that makes it possible to print different materials along the built direction and within a single layer of a component. At the interface between the different materials, the deposited powders melt, mix and solidify very rapidly, than can produce a range of desired and undesired phases, residual stresses and defects. Here we applied Bragg edge imaging to characterize M2LPBF specimens of stainless steel and CuCrZr with vertical and horizontal interfaces. A diffuse interface is observed in the samples with both vertical and horizontal interfaces. The analysis of the (111) and (200) Bragg edges height across the samples demonstrated a clear difference between the crystallographic texture of both alloys, with a strong alignment of the (002) planes along one of the transversal directions in the steel and a random texture within the copper alloy.
Failure characterization by pull-out test on structural inserts in sandwich panels used in the aerospace industry applying neutron imaging
Authors: Soria S.R. , Marín J.H. , Losko A.
Published: October 2023

In the present work, the failure of the inserts potted on the structural sandwich panel used in satellites was analysed. Inserts were tested by pull-out test to evaluate the strength of the joint between the potting mass and the sandwich panel. Neutron experiments were performed in NECTAR, the thermal neutron imaging facility at FRM II. Two series of specimens with dimensions of 10x10x2.5 cm3 and 5x5x2.5 cm3 were tested by applying different normal loads to detect singular points in the load-displacement curves. Images were acquired using thermal neutrons and filtering the beam obtaining images formed by gamma rays and epithermal neutrons. The filter was formed by a cadmiun (Cd) layer on the neutron beam. The results determined the usefulness of this characterization technique to analyse the dynamics failure of the insert union by the use of in-situ experiments in future studies.
Visualization of local two-phase flow structure in a packed bed of spheres
Authors: Ito D , Odaira N , Ito K , Saito Y
Published: October 2023

A two-phase flow structure in porous media is essential to clarify the debris cooling characteristics during a severe accident in nuclear power plants. In previous experimental studies, a packed bed of spheres has been used instead of the porous debris bed. Many models to predict the flow and heat transfer characteristics in the packed bed have been proposed based on the experimental data in the sphere-packed bed. However, those models have not considered the local flow structure, which should be studied to enhance the prediction accuracy. In this study, the local flow structure of the air-water two-phase flow in the unit model of the sphere-packed bed was measured by neutron computed tomography. The distribution of the gas phase was reconstructed by acquired images. From these results, the breakup and coalescence of the bubbles in the packed bed were evaluated.
Decrepitation process of a hydride forming material observed by neutron radiography
Authors: Biasetti A , Marín J , Meyer G , Borzone E M , Aversente N , Baruj A
Published: October 2023

Hydride-forming materials (HFM) are widely investigated for hydrogen storage, separation and purification, due to their reversible reaction with hydrogen at moderated pressures. These materials are mainly used in powder form and they show a considerable change in cell volume during the reaction with hydrogen (up to 25% for LaNi5). This change can exert significant mechanical stresses upon the container vessel walls. We have been studying this phenomenon by measuring the mechanical strains generated on the wall of a cylindrical vessel during hydrogen absorption/desorption cycling. The complexity of studying the mechanical effects is due to the granulometry, porosity and flowability of the powder material which are affected by the decrepitation phenomenon that the material suffers along the cycles. Neutron imaging has proven to be a useful technique to visualize the evolution of the powder rearrangement inside the reservoir. We have identified some key aspects for understanding the relationship between the degree of compaction of the powder, the geometrical parameters of the reservoir (slenderness, wall thickness, filling level), the equivalent pressure exerted by the material against the reactor walls, as well as the number of cycles.
Design of a hydrogen storage device for evaluating tensions induced by volumetric expansion during hydrogen absorption
Authors: Marín J , Biasetti A , Meyer G , Borzone E M , Aversente N , Baruj A
Published: October 2023

Hydride-Forming Materials (HFM) allow the storage of hydrogen in solid state. The reaction can be reversed by delivering heat or lowering pressure, releasing gaseous hydrogen. When hydrogen is incorporated into its structure, the HFM experiences a volumetric expansion. In the case of LaNi5, a commonly studied AB5 type material, it can be as high as 25%. This mismatch produces stress within the material, which breaks apart. Successive cycles produce further decrepitation into a fine powder, which reduces heat transfer, and compaction, which affects diffusion of the gas phase and, in extreme cases, may deform or even break the container. For these reasons, in order to make a safe and efficient hydrogen storage system it is of crucial importance to characterize the volumetric expansion and the mechanical stress originated by the HFM. With these objectives, we have designed a device with an adequate geometry for being studied by neutron imaging. This technique allows to observe the interior of a metallic vessel and, at the same time, to distinguish the hydrogen distribution in a HFM through a convenient contrast difference. Furthermore, we have designed and manufactured a mechanical indicator of the volume changes caused by cycling and allows their direct observation.
Weak local upwelling may elevate the risks of harmful algal blooms and hypoxia in shallow waters during the warm season
Authors: Wu Wenfan , Zhai Fangguo , Gu Yanzhen , Liu Cong , Li Peiliang
Published: October 2023

Harmful algal blooms (HABs) and hypoxia, as common ecological disasters, are typically site-specific and recurrent, causing enduring environmental problems for coastal communities. Although these issues are often attributed to coastal eutrophication, in certain low-nutrient areas, such ecological disasters still frequently occur while the underlying cause is poorly understood. A prime example is the Qinhuangdao coastal waters in North China. This study intends to investigate the controlling factors of such incongruous ecological issues recurring in those low-nutrient areas with a case study of Qinhuangdao, utilizing numerical models and satellite observations. The result indicates that the weak tide-induced upwelling during summer creates favorable conditions (warm water with high transparency) for the occurrence of HABs and hypoxia in this region. It is due to that Qinhuangdao is precisely situated at the current amphidromic point of semi-diurnal tides, characterized by weak tide mixing. Likewise, the same story happens on the northern shelf of the Shandong Peninsula, where ecological problems are also prominent in China. The present study implies that shallow waters with weak local upwelling are susceptible to ecological issues during the warm season. This finding challenges the traditional view that strong-upwelling zones are more vulnerable to ecological disasters due to ample nutrient supply within the euphotic layer. It implies that tidal dynamics can greatly affect the vulnerability of coastal waters to ecological issues, which can be of significance to coastal management. Furthermore, the finding may have broader global applicability, given the ubiquity of tide-induced upwelling in various other coastal regions.
Effects of the morphology and diameter of TiO2 nanofibers as light-scattering layers on the efficiency of dye-sensitized solar cells
Authors: Fajariah Amalia Rohmah , Adiperdana Budi , Faizal Ferry , Aprilia Annisa , Safriani Lusi
Published: October 2023

In this study, TiO2 nanofibers was synthesized using electrospinning method with varying applied voltage (10 kV–20 kV) to obtain high surface-volume ratio and porous material. As the applied voltage increased, diameter of TiO2 nanofibers decreased and the presence of beads disappeared resulting in homogeneous nanofibers. At applied voltage higher than 16 kV, TiO2 nanofibers have diameter less than 100 nm. TiO2 nanofibers are deposited on top of TiO2 nanoparticles which act as a light-scattering layer. Based on the I–V characteristic, TiO2 nanofibers produced by applied voltage of 18 kV gives the highest efficiency of 2.38% with JSC 6.37 mA cm−2, VOC of 0.74 V and fill factor of 50.54%. Adding the TiO2 nanofibers as light-scattering layer improve and extend the path of light, thereby increasing the power conversion efficiency of dye-sensitized solar cells.
Non-Newtonian pulsatile blood flow through the stenosed arteries: comparison between the viscoelastic and elastic arterial wall in response to the alterations
Authors: Jannati Sahel , Shahri Mohammad Nabizadeh , Jafarzadeh Nahid , Firouzi Faramarz
Published: October 2023

In this study, we investigate the impact of aortic stenosis on the hemodynamics of pulsatile blood flow within a 3D aortic model. Employing a non-Newtonian Casson model with a hematocrit of 45%, our study introduces a preliminary hypothesis to simulate blood flow dynamics, incorporating both linear elastic and viscoelastic models to define the mechanical characteristics of the artery. Through simulations conducted with Ansys-Cfx (version 15), we utilize a 2-way fluid-structure interaction (FSI) approach, employing a Lagrangian-Eulerian formulation with second-order accuracy. We explore the influence of stenosis severity on variables including velocity profiles, pressure distribution, shear stress, wall displacement, and changes in the OSI parameter. Our investigation encompasses arteries with both elastic and viscoelastic walls. The key findings that arise from our results highlight the viscoelastic model’s demonstration of reduced radial wall displacement when compared to the linear elastic model. Additionally, we observe that elevated arterial stenosis percentages lead to the elongation of vortex length, heightened wall shear stress, and increased slope of velocity profiles downstream of the stenosed region. Furthermore, bulky obstruction of viscoelastic arteries as opposed to elastic, resulted in a maximum 5 percent increase in velocity profile and a 29.6% decrease in radial displacement. The zenith of shear stress occurs concomitantly with the velocity’s peak within the stenosed area. Viscoelastic arterial wall shear stress at the stenosis site escalates due to the rapid expansion of the stenosis. The viscoelastic wall, responding with a blend of viscous and elastic characteristics to applied stress, undergoes slight deformation in shape. Following stress reduction, the wall gradually reverts to its original form, thus alleviating some of the applied stress. In contrast, the elastic wall retains its altered shape due to stress preservation within the material. Additionally, we ascertain an augmentation in radial displacement corresponding with increased artery stenosis.