bluuebunny/crossref_metadata_2025 huggingface dataset:
Amorphous MoS2 from a machine learning inter-atomic potential
Authors: Kety Kossi , Namsrai Tsogbadrakh , Nawaz Huma , Rostami Samare , Seriani Nicola
Published: May 2024

Amorphous molybdenum disulfide has shown potential as a hydrogen evolution catalyst, but the origin of its high activity is unclear, as is its atomic structure. Here, we have developed a classical inter-atomic potential using the charge equilibration neural network method, and we have employed it to generate atomic models of amorphous MoS2 by melting and quenching processes. The amorphous phase contains an abundance of molybdenum and sulfur atoms in low coordination. Besides the 6-coordinated molybdenum typical of the crystalline phases, a substantial fraction displays coordinations 4 and 5. The amorphous phase is also characterized by the appearance of direct S–S bonds. Density functional theory shows that the amorphous phase is metallic, with a considerable contribution of the 4-coordinated molybdenum to the density of states at the Fermi level. S–S bonds are related to the reduction of sulfur, with the excess electrons spread over several molybdenum atoms. Moreover, S–S bond formation is associated with a distinctive broadening of the 3s states, which could be exploited for experimental characterization of the amorphous phases. The large variety of local environments and the high density of electronic states at the Fermi level may play a positive role in increasing the electrocatalytic activity of this compound.
Intrinsic superconducting phase battery
Authors: Li Feng , Higashi Masayuki , Sato Taichi , Tanaka Masamitsu , Fujimaki Akira
Published: May 2024

Leveraging the quantization properties inherent in superconductors, we present the development of an intrinsic superconducting phase battery. This advancement is achieved by integrating a ferromagnetic π-phase Josephson junction (π-JJ) within a superconducting ring. The core innovation lies in harnessing the potential energy of the π-JJ to generate an intrinsic circulating current, thereby inducing a phase difference as the current goes through the geometric inductance. This mechanism allows for tuning the phase bias φ (0 < φ < π) through an arrangement of the geometric inductance in the battery. We integrate the intrinsic phase batteries into superconducting quantum interference devices, where we verified the effectiveness of the induced phase bias. The polarity of the phase battery is determined by the direction of the intrinsic circulating current, which can be initialized by an external magnetic field. The design methodology for precise intrinsic phase bias has been established. Our findings not only show the feasibility of generating an intrinsic and adjustable phase bias using established fabrication techniques but also open new avenues for enhancing the design, efficiency, and functionality of superconducting electronics, promising to accelerate advancements in digital and quantum computing technologies.
Feasibility of a physiotherapist-supervised walking program with telephone coaching to increase physical activity following acquired brain injury
Authors: Payne Caitlyn , Gesch Janelle , Smits Esther , Brakenridge Charlotte , Johnston Venerina , Gardiner Paul A. , Comans Tracy , Bell Ryan , Gane Elise
Published: May 2024

Background Physical activity has health benefits for adults with acquired brain injury, but it is a challenge to increase physical activity during inpatient rehabilitation. The objectives of this pilot study were to determine whether a physiotherapy-supervised inpatient walking program was feasible and able to improve physical activity and sedentary behaviour in the short and medium term. Methods Adults with acquired brain injury receiving inpatient rehabilitation undertook twice-weekly supervised walks plus behavioural therapy for 4 weeks. Feasibility was measured via recruitment, participation and drop out rates, adverse events and intervention delivery costs. Physical activity and sedentary behaviour were measured with an activPAL. Assessments were conducted at baseline, post-intervention and 3–6 months post-intervention. Results The program was safe to deliver (no adverse events), recruitment rate was 55% (16/29) and the participation rate for eligible individuals was high (14/19, 74%). However, the program had a high drop out rate (7/16, 44%) and physical activity and sedentary behaviour did not significantly change during the 4-week intervention. Costs were AU$427.71/participant. Physical activity and sedentary behaviour did improve 3–6 months after the intervention (vs baseline, on average: +3913 steps per day, 95% CI: 671, 7156). Conclusion This pilot study demonstrated a supervised physiotherapy walking program is safe and feasible to recruit in an inpatient setting. However, drop out during the study was high and behaviour change did not occur. More work is required to boost physical activity during sub-acute rehabilitation for acquired brain injury.
University students’ recognition of typical wave optics patterns
Authors: Susac Ana , Küchemann Stefan , Planinic Maja , Kuhn Jochen
Published: May 2024

The recognition and distinction of typical interference and diffraction patterns are among the expected learning outcomes of studying wave optics. Previous studies have reported high school students’ difficulties with this task. In this study, we investigated university students’ ability to distinguish typical wave optics patterns obtained by the double slit, single slit, and diffraction grating. We also used eye tracking to obtain an insight into the distribution of students’ visual attention during the task. The results showed that university students had similar difficulties in recognizing wave optics patterns as high school students. They mostly struggled with identification of the double-slit interference patterns and diffraction grating patterns of monochromatic light while they were more successful in recognition of the diffraction pattern of white light on an optical grating and single-slit diffraction patterns. The eye-tracking data also revealed that students spent more time attending colourful than grey patterns in questions regarding diffraction of white light on an optical grating, thus suggesting that they were aware that the diffraction grating separates white light into colours. In questions regarding monochromatic light patterns, students overall mostly attended the single-slit diffraction pattern probably because of its distinct central maximum. Furthermore, the longer fixation duration for patterns compared to the text implies that students found it easier to extract information from the text than from the patterns. No prior research has compared the number of transitions during problem solving with the accuracy of the answers. In this study, we observed that students who incorrectly solved a task demonstrated a significantly higher number of gaze transitions between the question and the options, as well as among different options. The results of this study indicate that the recognition of typical wave optics patterns is also difficult for university students, thus suggesting that more attention should be paid to systematic observation and identification of key features of basic wave optics phenomena in lecture demonstrations and student laboratories.
First-principles study of two-dimensional transition metal carbide M

n

+
1

C

n

O2 (M = Nb,Ta)
Authors: Shang Yue , Han Yifan , Wan Wenhui , Liu Yong , Ge Yanfeng
Published: May 2024

In the present work, the three stable MXenes M

n

+
1

C

n

O2 (M = Nb,Ta) are explored based on first-principles calculations. These materials are important derivatives of 2D materials and exhibit distinctive properties, holding vast potential in nanodevices. All these M

n

+
1

C

n

O2 (M = Nb,Ta) materials exhibit outstanding superconducting performance, with corresponding superconducting transition temperatures of 23.00 K, 25.00 K, and 29.00 K. Analysis reveals that the high superconducting transition temperatures of MXenes M

n

+
1

C

n

O2 (M = Nb,Ta) are closely associated with the high value of the logarithmic average of phonon frequencies,

ω

log

, and the strong electron–phonon coupling, attributed to the crucial contribution of low-frequency phonons. Additionally, we applied strain treatments of 2% and 4% to M

n

+
1

C

n

O2 (M = Nb,Ta), resulting in varying changes in superconducting transition temperatures under different strains.
A novel error modulation rotation scheme for dual-axis rotational inertial navigation system
Authors: Wei Dong , Guan Bofan , Fu Qiangwen , Li Sihai
Published: May 2024

Dual-axis rotational inertial navigation system (RINS) can effectively suppress the error accumulation of inertial navigation system, thereby improve the long-term navigation accuracy through rotating inertial measurement unit (IMU) according to corresponding rotation scheme. The navigation accuracy of RINS is predominantly contingent on the IMU rotation scheme. A reasonable rotation scheme can effectively attenuate or even obviate the navigation errors stemming from IMU errors, whereas an ill-considered scheme may lead to swift divergence of navigation errors. In this paper, the principle of IMU errors suppression is meticulously analyzed during rotation. By comprehensively evaluating the impact of individual IMU errors on navigation accuracy alongside their corresponding error modulation characteristics, a novel 32-position rotation scheme is devised. The proposed scheme demonstrates a notable capacity to minimize the adverse effects of IMU errors on navigation accuracy and to enhance error suppression efficacy within a modulation cycle. Meanwhile, the long-endurance navigation accuracy of RINS is substantially enhanced. The efficacy of the 32-position scheme posited herein is empirically substantiated through a 24 h simulation and navigation experiment.
Bicone nanoflower evolution and multi-peak emission of polymer caped Cu doped ZnO
Authors: Neelamkodan Hind , Megha Unikoth , Chennabasappa Madhu , Binitha Manathanath Puzhakkara
Published: May 2024

A low-temperature polymer-assisted wet chemical method was used to synthesise Cu-doped ZnO bicone nanoflowers at three different polyethylene glycol (PEG) concentrations. The effects of PEG concentration on the structural, morphological and optical properties of Cu doped ZnO nanostructures were studied. X-ray diffraction studies revealed that the as-synthesized Cu doped ZnO nanostructures are highly crystalline with a hexagonal wurtzite phase. The scanning electron microscopy analysis showed that the prepared nanostructures have bicone- nanoflower morphology and PEG concentration has strongly influenced the size as well the shape of nanoflowers. The TEM analysis confirmed the nanoflower morphology and the presence of diffraction planes obtained from the XRD data. The compositional analysis was performed by x-ray photoelectron Spectroscopy. The surface passivation effect of PEG on the band gap energies was studied by analysing UV -visible spectra of all the samples. The room-temperature fluorescent spectra of all the nanoflowers showed multiple peak emissions, both in the ultra-violet and visible regions, with varying intensities. These recasted multiple peaks are attributed to the morphological modification caused by the PEG addition.
Global existence of weak solutions and weak–strong uniqueness for nonisothermal Maxwell–Stefan systems
*
Authors: Georgiadis Stefanos , Jüngel Ansgar
Published: May 2024

The dynamics of multicomponent gas mixtures with vanishing barycentric velocity is described by Maxwell–Stefan equations with mass diffusion and heat conduction. The equations consist of the mass and energy balances, coupled to an algebraic system that relates the partial velocities and driving forces. The global existence of weak solutions to this system in a bounded domain with no-flux boundary conditions is proved by using the boundedness-by-entropy method. A priori estimates are obtained from the entropy inequality which originates from the consistent thermodynamic modelling. Furthermore, a conditional weak–strong uniqueness property is shown by using the relative entropy method.
Self-driven ion deflectometry measurements using MeV fusion-driven protons and accelerated deuterons in the deuterated hybrid x-pinch on the MAIZE LTD generator
Authors: Munzar Vojtech , Dowhan George , Klir Daniel , Novotny Jan , Rezac Karel , Chen Joe , Cikhardt Jakub , Cikhardtova Balzima , Juras Vojtech , Jordan Nicholas , Kubes Pavel , Malir Jakub , Tafoya Landon , Turek Karel , McBride Ryan
Published: May 2024

We report on the results of point-projection ion deflectometry measurements from a mid-size university z-pinch experiment. A 1 MA 8 kJ LTD generator at the University of Michigan (called MAIZE) drove a hybrid x-pinch (HXP) with a deuterated polyethylene fiber load to produce a point-like source of MeV ions for backlighting. In these experiments, 2.7 MeV protons were generated by DD beam-target fusion reactions. Due to the kinematics of beam-target fusion, the proton energies were down-shifted from the more standard 3.02 MeV proton energy that is released from the center-of-mass rest frame of a DD reaction. In addition to the 2.7 MeV protons, strongly anisotropic beams of 3 MeV accelerated deuterons were detected by ion diagnostics placed at a radial distance of 90 mm from the x-pinch. Numerical reconstruction of experimental data generated by deflected hydrogen ion trajectories evaluated the total current in the vacuum load region. Numerical ion-tracking simulations show that accelerated deuteron beams exited the ion source region at large angles with respect to the pinch current direction.
Effect of the spin-orbit coupling and Hubbard corrections in predicting the electronic and magnetic properties of vacancy-ordered double perovskites A2WCl6 (A = Rb and Cs)
Authors: Touati Mourad , Zemouli Mostefa , Akil Zoheir , Saadaoui Fatiha , Meskine Mohamed , Boutaleb Habib , Amara Kadda
Published: May 2024

The structural, elastic, electronic, and magnetic properties of the vacancy ordered double perovskite compounds A2WCl6 (A = Rb, Cs) have been investigated within the full-potential linearized augmented plane waves (FP-LAPW) method. The structural properties in the cubic phase were examined and are consistent with the available experimental results. The materials are more stable in the ferromagnetic phase. The mechanical, dynamical and the thermodynamical stability have also been verified. The electronic and magnetic properties were first calculated by GGA-WC approximation, the studied materials are found to be half-metallic. Including Hubbard correction (U), the W-d states move towards higher energy enlarging the band gap in the spin-down channel. The spin–orbit coupling (SOC) was added to GGA-WC+U which reveal that these compounds behave as semiconductors in both spin channels. The density of states showed that the valence band is mainly characterized by the W-d together with Cl-p states while the conduction band is dominated by W-d and (Cs/Rb)-d states. The calculated properties present semiconducting ferromagnetic nature that is considered as necessary factor in spintronics applications.
Comprehensive design and analysis of thin film Sb2S3/CIGS tandem solar cell: TCAD simulation approach
Authors: Salem Marwa S , Shaker Ahmed , Aledaily Arwa N , Alanazi Adwan , A Al-Dhlan Kawther , Okil Mohamed
Published: May 2024

This research presents a design and analysis of a tandem solar cell, combining thin film wide bandgap Sb2S3 (1.72 eV) and narrow bandgap CIGS (1.15 eV) for the top and bottom sub-cells, respectively. The integration of all thin film layers enhances flexibility, rendering the tandem solar cell suitable for applications such as wearable electronics. To optimize the power conversion efficiency (PCE) of the tandem solar device, advanced technology computer-aided design (TCAD) simulation tools are employed to estimate loss mechanisms and fine-tune parameters for each layer. An experimentally validated optoelectronic model is introduced, calibrated and validated against fabricated reference solar cells for the individual top and bottom cells. The calibrated model is then utilized to propose optimization routines for the Sb2S3/CIGS tandem solar cell. The initial tandem cell exhibits a J
SC of 15.72 mA cm−2 and a PCE of 15.36%. The efficiency drop in the tandem configuration is identified primarily in the top cell. A systematic optimization process for the top cell is initiated, exploring various configurations, including HTL-free and ETL-free setups. Moreover, an np homojunction structure for the top cell is proposed. Optimization routines are applied that involve determining optimal thickness and doping concentration of the n-layer, investigating the effect of p-layer doping concentration, and exploring the influence of the work function of the front contact. As a result, the tandem cell efficiency is significantly improved to 23.33% at the current matching point (CMP), with a J
SC of 17.15 mA cm−2. The findings contribute to the advancement of thin-film tandem solar cell technology, showcasing its potential for efficient and flexible photovoltaic applications.
Effect of tin doping on the structural, optical, and dielectric properties of unintentionally β-Ga2O3 single crystal
Authors: Mohamed H F , Li Baizhong , Sai Qinglin , Xia Changtai , Qi Hongji , Mohamed Aml M , Ibrahim E M M , Ahmed A M
Published: May 2024

This paper studied the structural, optical, electrical, and dielectric properties of the undoped and 0.05 mol% Sn-doped β-Ga2O3 single crystals through comprehensive characterizations by x-ray diffraction (XRD), Raman scattering, Optical transmittance spectroscopy, x-ray photoelectron spectroscopy (XPS), Ultraviolet photoelectron (UPS) spectroscopy, and dielectric measurements. The optical bandgap decreases as Sn content increases. The results of XPS showed that Sn atoms were successfully added to the host β-Ga2O3 crystal. The position of the Fermi level of 0.05 mol% Sn-doped β-Ga2O3 is calculated to be 2.56 eV above the valence band and 1.85 eV beneath the conduction band. Also, the computed value of the work function of 0.05% mole Sn-doped β-Ga2O3 is 4.53 eV. AC conductivity increases, while dielectric loss and dielectric constant decrease with increasing frequency.
Disentangling photon rings beyond General Relativity with future radio-telescope arrays
Authors: Carballo-Rubio Raúl , Delaporte Héloïse , Eichhorn Astrid , Held Aaron
Published: May 2024

New physics beyond General Relativity can modify image features of black holes and
horizonless spacetimes and increase the separation between photon rings. This motivates us to
explore synthetic images consisting of two thin rings. Our synthetic images are parameterized by
the separation as well as the relative flux density of the two rings. We perform fits to the
visibility amplitude and analyze closure quantities. The current Event Horizon Telescope array
cannot detect the presence of a second ring in the region of parameters motivated by particular
new-physics cases. We show that this can be improved in three ways: first, if the array is
upgraded with Earth-based telescopes with sufficiently high sensitivity, second, if the array is
upgraded with a space-based station and third, if super-resolution techniques are used for the
data obtained by the array.
Neutrino mass measurement with cosmic gravitational focusing
Authors: Ge Shao-Feng , Pasquini Pedro , Tan Liang
Published: May 2024

We thoroughly explore the cosmic gravitational focusing
of cosmic neutrino fluid (CνF) by dark matter (DM) halo
using both general relativity for a point
source of gravitational potential and Boltzmann
equations for continuous overdensities. Derived in
the general way for both relativistic and
non-relativistic neutrinos, our results
show that the effect has fourth power
dependence on the neutrino mass and temperature.
With nonlinear mass dependence which is different
from the cosmic microwave background (CMB) and
large scale structure (LSS) observations,
the cosmic gravitational focusing can provide an
independent cosmological way of measuring the neutrino
mass and ordering. We take DESI as an example to
illustrate that the projected sensitivity as well as its
synergy with existing terrestrial neutrino oscillation
experiments and other cosmological observations can
significantly improve the neutrino mass measurement.
Holographic massive plasma state in Friedman universe: cosmological fine-tuning and coincidence problems
Authors: Xue 生 She-Sheng 薛社
Published: May 2024

Massive particle and antiparticle pair production and
oscillation on the horizon form a holographic and massive pair plasma state in the Friedman Universe. Via this state, the Einstein
cosmology term (dark energy) interacts with matter and radiation and is time-varying Λ̃ in the Universe's evolution.
It is determined by a close set of ordinary differential equations for dark energy, matter, and radiation energy densities. The solutions are unique, provided the initial conditions given by observations.
In inflation and reheating, dark energy density decreases from the inflation scale, converting to matter and radiation energy densities.
In standard cosmology, matter and radiation energy densities convert to dark energy density, reaching the present Universe. By comparing with ΛCDM, quintessence and dark energy interacting models, we show that
these results can be the possible solutions for cosmological fine-tuning and coincidence problems.
Multipole expansion of the gravitational field in a general class of fourth-order theories of gravity and the application in gyroscopic precession
Authors: Wu Bofeng , Liang En-Wei
Published: May 2024

A viable weak-field and slow-motion approximation method is constructed in
 F(R, RμνRμν, Rμν ρσRμν ρσ
) gravity, a general class of
fourth-order theories of gravity. By applying this method, the metric, presented in the form of
the multipole expansion, outside a spatially compact source up to 1/c
3 order is provided, and
the closed-form expressions for the source multipole moments are all presented explicitly. The
metric consists of the massless tensor part, the massive scalar part, and the massive tensor part,
where the former is exactly the metric in General Relativity, and the latter two are the
corrections to it. It is shown that the corrections bear the Yukawa-like dependence on the two
massive parameters and predict the appearance of six additional sets of source multipole moments,
which indicates that up to 1/c
3 order, there exist six degrees of freedom beyond General
Relativity within F(R, RμνRμν, Rμν ρσRμν ρσ
)
gravity. By means of the metric, for a gyroscope moving around the source without experiencing any
torque, the multipole expansions of its spin's angular velocities of the Thomas precession, the
geodetic precession, and the Lense-Thirring precession are derived, and from them, the corrections
to the angular velocities of the three types of precession in General Relativity can be read
off. These results indicate that differently from f(R) or f(R,𝒢) gravity, the most
salient feature of the general F(R, RμνRμν, Rμν ρσRμν ρσ
)
gravity is that it gives the nonvanishing correction to
the gyroscopic spin's angular velocity of the Lense-Thirring precession in General Relativity.
KMT-2023-BLG-1431Lb: A New q < 10−4 Microlensing Planet from a Subtle Signature
Authors: Bell Aislyn , Zhang Jiyuan , Zang Weicheng , Jung Youn Kil , Yee Jennifer C. , Yang Hongjing , Sumi Takahiro , Udalski Andrzej ,   Leading Authors, Albrow Michael D. , Chung Sun-Ju , Gould Andrew , Han Cheongho , Hwang Kyu-Ha , Ryu Yoon-Hyun , Shin In-Gu , Shvartzvald Yossi , Cha Sang-Mok , Kim Dong-Jin , Kim Seung-Lee , Lee Chung-Uk , Lee Dong-Joo , Lee Yongseok , Park Byeong-Gon , Pogge Richard W. ,   The KMTNet Collaboration, Tang Yunyi , McCormick Jennie , Dong Subo , Liu Zhuokai , de Almeida Leandro , Mao Shude , Maoz Dan , Zhu Wei ,   The MAP & FUN Follow-up Team, Abe Fumio , Barry Richard , Bennett David P. , Bhattacharya Aparna , Bond Ian A. , Fujii Hirosane , Fukui Akihiko , Hamada Ryusei , Hirao Yuki , Silva Stela Ishitani , Itow Yoshitaka , Kirikawa Rintaro , Kondo Iona , Koshimoto Naoki , Matsubara Yutaka , Matsumoto Sho , Miyazaki Shota , Muraki Yasushi , Okamura Arisa , Lmschenk Greg , Ranc Clément , Rattenbury Nicholas J. , Satoh Yuki , Suzuki Daisuke , Toda Taiga , Tomoyoshi Mio , Tristram Paul J. , Vandorou Aikaterini , Yama Hibiki , Yamashita Kansuke ,   The MOA Collaboration, Mróz Przemek , Skowron Jan , Poleski Radoslaw , Szymański Michał K. , Soszyński Igor , Pietrukowicz Paweł , Kozłowski Szymon , Ulaczyk Krzysztof , Rybicki Krzysztof A. , Iwanek Patryk , Wrona Marcin , Gromadzki Mariusz ,   The OGLE Collaboration
Published: May 2024

The current studies of microlensing planets are limited by small number statistics. Follow-up observations of high-magnification microlensing events can efficiently form a statistical planetary sample. Since 2020, the Korea Microlensing Telescope Network (KMTNet) and the Las Cumbres Observatory (LCO) global network have been conducting a follow-up program for high-magnification KMTNet events. Here, we report the detection and analysis of a microlensing planetary event, KMT-2023-BLG-1431, for which the subtle (0.05 mag) and short-lived (5 hr) planetary signature was characterized by the follow-up from KMTNet and LCO. A binary-lens single-source (2L1S) analysis reveals a planet/host mass ratio of q = (0.72 ± 0.07) × 10−4, and the single-lens binary-source (1L2S) model is excluded by Δχ
2 = 80. A Bayesian analysis using a Galactic model yields estimates of the host star mass of

M

host

=

0.57

−
0.29

+
0.33

M

⊙

, the planetary mass of

M

planet

=

13.5

−
6.8

+
8.1

M

⊕

, and the lens distance of

D

L

=

6.9

−
1.7

+
0.8

kpc. The projected planet-host separation of

a

⊥

=

2.3

−
0.5

+
0.5

au or

a

⊥

=

3.2

−
0.8

+
0.7

au, subject to the close/wide degeneracy. We also find that without the follow-up data, the survey-only data cannot break the degeneracy of central/resonant caustics and the degeneracy of 2L1S/1L2S models, showing the importance of follow-up observations for current microlensing surveys.
A family of quantum von Neumann architecture
Authors: Wang 王 Dong-Sheng 东升
Published: May 2024

We develop universal quantum computing models that form a family of quantum von Neumann architectures, with modular units of memory, control, CPU, and internet, besides input and output. This family contains three generations characterized by dynamical quantum resource theory, and it also circumvents no-go theorems on quantum programming and control. Besides universality, such a family satisfies other desirable engineering requirements on system and algorithm design, such as modularity and programmability, hence serves as a unique approach to building universal quantum computers.
Topological phases and edge modes of an uneven ladder
Authors: Shang 商 Wen-Chuang 文创 , Han 韩 Yi-Ning 熠宁 , Endo Shimpei , Gao 高 Chao 超
Published: May 2024

We investigate the topological properties of a two-chain quantum ladder with uneven legs, i.e., the two chains differ in their periods by a factor of 2. Such an uneven ladder presents rich band structures classified by the closure of either direct or indirect bandgaps. It also provides opportunities to explore fundamental concepts concerning band topology and edge modes, including the difference of intracellular and intercellular Zak phases, and the role of the inversion symmetry (IS). We calculate the Zak phases of the two kinds and find excellent agreement with the dipole moment and extra charge accumulation. We also find that configurations with IS feature a pair of degenerate two-side edge modes emerging as the closure of the direct bandgap, while configurations without IS feature one-side edge modes emerging as not only the closure of both direct and indirect bandgaps but also within the band continuum. Furthermore, by projecting to the two sublattices, we find that the effective Bloch Hamiltonian corresponds to that of a generalized Su–Schrieffer–Heeger model or the Rice–Mele model whose hopping amplitudes depend on the quasimomentum. In this way, the topological phases can be efficiently extracted through winding numbers. We propose that uneven ladders can be realized by spin-dependent optical lattices and their rich topological characteristics can be examined by near future experiments.
Neuritogenic glycosaminoglycan hydrogels promote functional recovery after severe traumatic brain injury
Authors: Gonsalves Nathan , Sun Min Kyoung , Chopra Pradeep , Latchoumane Charles-Francois , Bajwa Simar , Tang Ruiping , Patel Bianca , Boons Geert-Jan , Karumbaiah Lohitash
Published: May 2024

Objective. Severe traumatic brain injury (sTBI) induced neuronal loss and brain atrophy contribute significantly to long-term disabilities. Brain extracellular matrix (ECM) associated chondroitin sulfate (CS) glycosaminoglycans promote neural stem cell (NSC) maintenance, and CS hydrogel implants have demonstrated the ability to enhance neuroprotection, in preclinical sTBI studies. However, the ability of neuritogenic chimeric peptide (CP) functionalized CS hydrogels in promoting functional recovery, after controlled cortical impact (CCI) and suction ablation (SA) induced sTBI, has not been previously demonstrated. We hypothesized that neuritogenic (CS)CP hydrogels will promote neuritogenesis of human NSCs, and accelerate brain tissue repair and functional recovery in sTBI rats. Approach. We synthesized chondroitin 4-O sulfate (CS-A)CP, and 4,6-O-sulfate (CS-E)CP hydrogels, using strain promoted azide-alkyne cycloaddition (SPAAC), to promote cell adhesion and neuritogenesis of human NSCs, in vitro; and assessed the ability of (CS-A)CP hydrogels in promoting tissue and functional repair, in a novel CCI-SA sTBI model, in vivo. Main results. Results indicated that (CS-E)CP hydrogels significantly enhanced human NSC aggregation and migration via focal adhesion kinase complexes, when compared to NSCs in (CS-A)CP hydrogels, in vitro. In contrast, NSCs encapsulated in (CS-A)CP hydrogels differentiated into neurons bearing longer neurites and showed greater spontaneous activity, when compared to those in (CS-E)CP hydrogels. The intracavitary implantation of (CS-A)CP hydrogels, acutely after CCI-SA-sTBI, prevented neuronal and axonal loss, as determined by immunohistochemical analyses. (CS-A)CP hydrogel implanted animals also demonstrated the significantly accelerated recovery of ‘reach-to-grasp’ function when compared to sTBI controls, over a period of 5-weeks. Significance. These findings demonstrate the neuritogenic and neuroprotective attributes of (CS)CP ‘click’ hydrogels, and open new avenues for the development of multifunctional glycomaterials that are functionalized with biorthogonal handles for sTBI repair.
Thermal conductivity in one-dimensional nonlinear disordered lattices: two kinds of scattering effects of hard-type and soft-type anharmonicities
Authors: Wang Jianjin , Xiong Chi , Xiong Daxing
Published: May 2024

Amorphous solids can be theoretically modeled by anharmonic disordered lattices, but most of the theoretical studies on thermal conductivity in such lattices only consider hard-type (HT) anharmonicity. In this study, we investigate the thermal conductivity κ of one-dimensional disordered lattices with both HT and soft-type (ST) anharmonic on-site potentials. Our results from molecular dynamics simulations and the quasi-harmonic Green–Kubo (QHGK) method show that while the HT model exhibits non-monotonic dependence of κ on anharmonicity, the ST model shows a monotonically increasing trend. This trend provides a novel approach to enhancing thermal conductivity in disordered systems. Additionally, the QHGK predictions for κ in the HT model are consistent with simulation results over a wide range of anharmonicity values; however, for the ST model, deviations appear as the anharmonicity becomes softer. This peculiar feature may be attributed to delocalization effects being dominant in contrast to the competing roles played by both delocalization and localization effects observed in the HT model.
Real-time charged track reconstruction for CLAS12
Authors: Gavalian Gagik ,   the CLAS12 collaboration
Published: May 2024

This paper presents the results of charged particle track reconstruction in CLAS12 using
artificial intelligence. In our approach, we use machine learning algorithms to reconstruct
tracks, including their momentum and direction, with high accuracy from raw hits of the CLAS12
drift chambers. The reconstruction is performed in real-time, with the rate of data acquisition,
and allows for the identification of event topologies in real-time. This approach revolutionizes
the Nuclear Physics experiments' data processing, allowing us to identify and categorize the
experimental data on the fly, and will lead to a significant reduction in experiment data
processing. It can also be used in streaming readout applications leading to more efficient data
acquisition and post-processing.
GEANT4 simulation of X-ray radiation for sterilizer based on high-current repetitively pulsed electron accelerator SINUS-320
Authors: Cherepennikov Yu. , Gauzshtein V. , Shevelev M.
Published: May 2024

Secondary X-ray radiation for the sterilizer based on high-current repetitively pulsed electrons accelerator SINUS-320 has been investigated. The energy of accelerated electrons is 500 keV. In this regard, there is a need for radiation protection during operation of the installation, which, in turn, leads to the importance of studying the dose rate of secondary X-ray radiation. The studies were carried out by statistical modeling using the GEANT4 simulation toolkit.
Radon concentration measurement with a high-sensitivity radon detector at the Yemilab
Authors: Seo Kyung Min , Kim Hyunsoo , Kim Yeong Duk , Lee Hye Young , Lee Jaison , Lee Moo Hyun , So Jungho , Yoon Sang Cheol , Yoon Young Soo
Published: May 2024

The radiation emitted from radon is a critical background in
rare event search experiments conducted at the Yemi Underground
Laboratory (Yemilab) in Jeongseon, Korea. A Radon Reduction System
(RRS) has been developed and installed in Yemilab to reduce radon
concentration in the air. The RRS primarily provides a purified air
of 50 m3/h to the cleanroom used to assemble crystal
detectors in the AMoRE, a neutrinoless double beta decay search
experiment. RRS can reduce the radon level by a factor of 300, so a
high-sensitivity radon detector was required. A highly sensitive
radon detector was constructed using a 70 L chamber with a large
PIN photodiode to measure radon concentration in the purified air.
The radon detector shows an excellent resolution of 72 keV (FWHM)
for 6.003 MeV alphas from 218Po decay and a sensitivity down
to 23.8 ± 2.1 mBq/m3 with a boil-off N2 gas sample.
The radon concentration level from the RRS measured by the radon
detector was below 0.29 Bq/m3 with a reduction factor of
about 300.
Moving from total risk to community-based risk trajectories increases transparency and equity in flood risk mitigation planning along urban rivers
Authors: Serafin Katherine A , Koseff Jeffrey R , Ouyang Derek , Suckale Jenny
Published: May 2024

After several years of drought, 2023 and early 2024 are reminders of the powers of California’s atmospheric rivers and the devastating flooding they can entail. Aged flood-mitigation infrastructure and climate change exacerbate flood risk for some communities more than for others, highlighting the challenge of equitably mitigating flood risk. Identifying inequities associated with infrastructure projects is now legally required by regional water boards in California, but tools are lacking for making this assessment systematically. We propose that risk trajectories, computed by adding a probabilistic wrapper of flood drivers to models already used in flood-risk-mitigation planning, allows planners to quantify the spatial and temporal variability of risk for communities along river and thereby increase procedural equity by making distributional equity more transparent. While our proposed approach is applicable generally, we demonstrate its impact in the case of San Francisquito Creek, California, where risk trajectories combined with a multi-tier engagement model, helped identify and prevent an inequitable risk transfer.
The impact of refrigeration on food losses and associated greenhouse gas emissions throughout the supply chain
Authors: Friedman-Heiman Aaron , Miller Shelie A
Published: May 2024

One-third of food produced globally is wasted while approximately 800 million people suffer from hunger. Meanwhile, food losses produce approximately 8% of total anthropogenic greenhouse gas (GHG) emissions. This study develops a food loss estimation tool to assess how improved access to the cold chain could impact food loss and its associated GHG emissions for seven food types in seven regions. This study estimates that poor cold chain infrastructure could be responsible for up to 620 million metric tons (Mmt) of food loss, responsible for 1.8 GtCO2-eq annually. Utilizing fully optimized cold chains could save over 100 Mmt of fruit and vegetable loss in South & Southeast Asia and over 700 Mmt CO2-eq in Sub-Saharan Africa. Developing more localized, less industrialized (‘farm-to-table’) food supply chains in both industrialized and non-industrialized contexts may save greater quantities of food than optimized cold chains. Utilizing localized supply chains could save over 250 Mmt of roots and tubers globally (over 100 Mmt more savings than those of an optimized cold chain) and reduce GHG emissions from meat losses in industrialized regions by over 300 Mmt CO2-eq. Due to the differences in the environmental intensity of food types, cold chain investments that prioritize reducing overall food losses will have very different outcomes than those that prioritize reducing GHG emissions.
The greenhouse gas performance of selected biodegradable and recalcitrant plastics in U.S. landfills
Authors: Wang Yixuan , Levis James W , Barlaz Morton A
Published: May 2024

Biodegradable plastics are often considered to exhibit superior environmental performance compared to conventional recalcitrant plastics. Here, we assess the greenhouse gas (GHG) emissions of selected biodegradable and recalcitrant plastics made from both fossil and biogenic carbon (C) as disposed in a national average U.S. landfill. This average landfill incorporates consideration of size, precipitation, landfill gas management, and gas collection installation schedule. The GHG emissions of an 80% biodegradable polycaprolactone (PCLf) made from fossil C and a 2% biodegradable poly(butylene succinate) (PBSb) made from biogenic C were evaluated to represent the range of anaerobic biodegradabilities. The 2% biodegradable PBSb has lower GHG emissions than the 80% biodegradable PCLf in the national average landfill. In the best case, which includes aggressive gas collection, conversion of gas to energy, and disposal in a large landfill, the PCLf results in 2423 kg CO2e/mt, which is well above PBSb (−1956 kg CO2e/mt), a hypothetical biogenic and 80% biodegradable PCLb (4739 kg CO2e/mt), and recalcitrant fossil plastic (0 kg CO2e/mt). From a disposal perspective, a recalcitrant biogenic plastic is optimal given the long-term storage of carbon. This study informs the direction of materials research to develop materials that minimize their overall environmental footprint at end-of-life.
Exploring the interplay between soil thermal and hydrological changes and their impact on carbon fluxes in permafrost ecosystems
Authors: Briones Valeria , Jafarov Elchin E , Genet Hélène , Rogers Brendan M , Rutter Ruth M , Carman Tobey B , Clein Joy , Euschkirchen Eugénie S , Schuur Edward AG , Watts Jennifer D , Natali Susan M
Published: May 2024

Accelerated warming of the Arctic can affect the global climate system by thawing permafrost and exposing organic carbon in soils to decompose and release greenhouse gases into the atmosphere. We used a process-based biosphere model (DVM-DOS-TEM) designed to simulate biophysical and biogeochemical interactions between the soil, vegetation, and atmosphere. We varied soil and environmental parameters to assess the impact on cryohydrological and biogeochemical outputs in the model. We analyzed the responses of ecosystem carbon balances to permafrost thaw by running site-level simulations at two long-term tundra ecological monitoring sites in Alaska: Eight Mile Lake (EML) and Imnavait Creek Watershed (IMN), which are characterized by similar tussock tundra vegetation but differing soil drainage conditions and climate. Model outputs showed agreement with field observations at both sites for soil physical properties and ecosystem CO2 fluxes. Model simulations of Net Ecosystem Exchange (NEE) showed an overestimation during the frozen season (higher CO2 emissions) at EML with a mean NEE of 26.98 ± 4.83 gC/m2/month compared to observational mean of 22.01 ± 5.67 gC/m2/month, and during the fall months at IMN, with a modeled mean of 19.21 ± 7.49 gC/m2/month compared to observation mean of 11.9 ± 4.45 gC/m2/month. Our results underscore the importance of representing the impact of soil drainage conditions on the thawing of permafrost soils, particularly poorly drained soils, which will drive the magnitude of carbon released at sites across the high-latitude tundra. These findings can help improve predictions of net carbon releases from thawing permafrost, ultimately contributing to a better understanding of the impact of Arctic warming on the global climate system.
General characterisation of Hamiltonians generating velocity-independent forces
Authors: Yip F , H Cheung A C
Published: May 2024

Dynamics generated from Hamiltonians enjoy potential pathways to quantisation, but standard Hamiltonians are only capable of generating conservative forces. Classes of Hamiltonians have been proposed in Berry and Shukla (2015 Proc. R. Soc. A
471 20150002) capable of generating non-conservative velocity-independent forces. Such Hamiltonians have been classified in the past, under the strict assumption that they are polynomial in momentum. This assumption is relaxed here to analyticity. In doing so, broader classes of Hamiltonians are discovered. By considering the Hamiltonian as a function of state space without introducing the Lagrangian and constructing a metric-like tensor, we develop strong general constraints on Hamiltonians generating velocity-independent forces and exhibit a surprising dichotomy between classes of such Hamiltonians. These results are applicable to any spatial domain of any dimension admitting well-defined Hamiltonian dynamics. As an example application, we apply these constraints to classify all Hamiltonian velocity-independent forces in two spatial dimensions, as well as all such Hamiltonians which do not generate an isotropic simple harmonic motion. The case of one spatial dimension is also discussed for the sake of completeness.
Design and Construction of Fan and Bulb Automation System
Authors: Usikalu M. R. , Eno M. B. , Ogunwale E. I. , Ayara W. A. , Ayanbisi O. W. , Esisio F. E
Published: May 2024

The automation system described in this project leverages the power of Bluetooth wireless communication to control the bulb and fan. The system utilize readily available components such as Arduino Uno, HC-05 Bluetooth module, and 4-channel relay module, it provides a cost-effective solution for creating a smart environment. The Arduino Uno acts as the central controller, receiving commands wirelessly via the Bluetooth module and subsequently controlling the power supply to connect devices through the relay module. This allows users to remotely turn on or off devices such as bulbs and fans, providing convenience and energy efficiency. The measured response times for turning on/off the fan and bulb in the automation system were found to be 15.47 μs for turning on the fan, 15.20 μs for turning off the fan, and 16.27 μs for turning on/off the bulb. These results indicate that the system is highly efficient and reliable in controlling the devices. Future enhancements can include the implementation of security measures to protect against unauthorized access and integration with other smart devices. The Bluetooth automation system showcases the potential for creating affordable and customizable automation solutions using easily accessible components
Physical Models for Sustainability using Fredholm Integro-Differential Equations: Applicability and Analysis of Chebyshev Polynomial Method
Authors: Fadugba S.E. , Olanrewaju A.F. , Akinremi O.J. , Duke-Umanah F.E.
Published: May 2024

Numerical analysis is concerned with the mathematical derivation, explanation and evaluation/analysis of algorithms, models and methods used to obtain numerical solutions for mathematical problems. This paper explores the reliability of the Chebyshev Polynomial Method (CPM) for solving a specific class of equations known as the second-order Fredholm Integro-Differential Equations (FIDEs). A series expansion of the Chebyshev polynomial is derived, used in solving these integral equations, and later on examined in terms of accuracy and convergence of solutions. The evaluation process involves a hybrid approach, combining manual methods and mathematical programs like MAPLE and MATLAB. In addition, three numerical examples were solved in which two truncation points are considered per each example. Furthermore, the performance of the CPM is reported in terms of accuracy, convergence, suitability, reliability and effectiveness in the context of the exact solution.
Sustainable Chitosan Supported Magnetite Nanocomposites for Sequestration of Rhodamine B Dye from the Environment
Authors: Dada A. O. , Inyinbor A. A. , Tokula B. E. , Ajanaku C. O. , Ayo-Akere S. , Latona D. F. , Ajanaku K.O.
Published: May 2024

This study investigated the sustainable chitosan supported magnetite nanocomposites (C-Fe3O4) for sequestration of Rhodamine B (RhB) Dye from environment. The synthesis of C-Fe3O4, its physicochemical characterization and synergistic influence of initial concentration of the dye and time of contact with the adsorbent during the sorption of Rhodamine B (RhB) on C-Fe3O4 were studied. The physicochemical properties indicated better equilibration via bulk density of 0.731 g/cm3, moisture content 7.2, point of zero charge (PZC) of 4 indicated suitability for RhB. Functional group of C-Fe3O4 determined by FTIR revealed characteristics peaks at 3433 cm−1 and 698 – 478 cm−1 confirming the successful formation by incorporation of chitosan and magnetite nanoparticles. Synergistic influence of the time of contact and initial concentration of Rb dye influenced the dye sorption. Effective adsorption of RhB onto C-Fe3O4 was studied using batch adsorption techniques at initial concentration (200 – 1000 ppm), contact time (10 – 120 min), stirring speed (120 rpm), temperature of 25 °C and adsorbent dosage of 100 mg. Rapid adsorption of RhB onto C-Fe3O4 was obtained at 10 min with 96.9% removal efficiency at highest RhB concentration of 1000 ppm. The study revealed the efficacy of contact time and initial dye concentration as imperative operational parameters majorly influencing sorption study.