bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of spatiotemporal plasma power distribution on the modeling of ignition kernel evolution in quiescent and turbulent methane/air mixtures
Authors: Johnson Praise Noah , Taneja Taaresh Sanjeev , Yang Suo
Published: July 2024

The present work improves a phenomenological plasma-assisted combustion model by integrating the spatiotemporal distribution of plasma power density, thereby considering the evolution of plasma streamers in the modeling, and subsequently, better predicting the ignition kernel evolution. The improved phenomenological model is validated against experiments representing the plasma discharge and post-discharge ignition kernel evolution. Specifically, the new model demonstrates a more accurate prediction of ultrafast gas heating and O2 dissociation during the plasma discharge, compared to the original model. In addition, the new model is found to closely match the experimental pressure wave and heated channel profiles post-discharge without the need for tuning the energy deposition (unlike the original model), highlighting its accuracy of post-discharge ignition kernel dynamics. The improved phenomenological model is then employed to investigate ignition kernel evolution for a stoichiometric methane-air discharge across various discharge gap configurations. Simulations reveal a non-uniform temperature and streamer distribution progressing from the electrode tips toward the center, contrasting uniform cylindrical discharges previously described in the original model. Streamer propagation is observed to be faster for larger gaps when maintained at the same average electric field for different discharge gaps. The tendency of smaller gaps to produce detached toroidal ignition kernels is observed, while larger gaps promote cylindrical and attached ignition kernels. Interactions between successive ignition kernels from consecutive discharges varied significantly, with the smallest gap (1 mm) promoting the quenching of the preceding ignition kernel due to the initial kernel–kernel separation. The intermediate gap (2 mm) promotes detached kernel growth. In contrast, in the largest gap (4 mm), kernels consistently combine and expand attached to electrodes. The impact of homogeneous isotropic turbulence is also explored, showing the persistence of ignition kernels early on but eventually quenching due to enhanced radical and heat losses with pronounced turbulence intensity.
High ionic conductivity materials Li3YBr6 and Li3LaBr6 for solid-state batteries: first-principles calculations
Authors: Li Yaping , McCoy Dylan , Bordonaro Justin , Simonson Jack W , Liu Shi-Yu , Wang Sanwu
Published: July 2024

High ionic conductivity solid-state electrolytes are essential for powerful solid-state lithium-ion batteries. With density functional theory and ab initio molecular dynamics simulations, we investigated the crystal structures of Li3YBr6 and Li3LaBr6. The lowest energy configurations with uniform distribution of lithium ions were identified. Both materials have wide electrochemical stability windows (ESW): 2.64 V and 2.57 V, respectively. The experimental ESW for Li3YBr6 is 2.50 V. Through extrapolating various temperature diffusion results, the conductivity of Li3YBr6 was obtained at room temperature, approximately 3.9 mS cm−1, which is comparable to the experimental value 3.3 mS cm−1. Li3LaBr6 has a higher conductivity, a 100% increase compared with Li3YBr6. The activation energies of Li3YBr6 and Li3LaBr6 through the Arrhenius plot are 0.26 eV and 0.24 eV, respectively, which is also close to the experimental value of 0.30 eV for Li3YBr6. This research explored high ionic conductivity halide materials and will contribute to developing solid-state lithium-ion batteries.
Multi-layered medium ultrasonic phased array sparse TFM imaging based on self-adaptive differential evolution algorithm
Authors: Yao Shuxin , Zhao Jianjun , Du Xiaozhong , Zhang Yanjie , Zhang Zhong
Published: July 2024

Multilayer Composite material structures have been widely used in modern engineering fields. However, defects within these materials can adversely affect mechanical properties. Ultrasonic phased array total focusing method (TFM) imaging has advantages of high precision and dynamic focusing over the entire range, achieving significant progress in homogeneous medium detection. However, heavy computational burdens of multilayer structures lead to inefficient imaging. To address this issue, a sparse-TFM imaging algorithm using ultrasonic phased arrays suitable for multilayer media is proposed in this paper. This method constructs a fitness function with constraints such as main lobe width and sidelobe peak. Its objective is to obtain the distribution of sparse array element positions using an self-adaptive differential evolution algorithm. Subsequently, the delay time of each array element in multilayer media sparse TFM is calculated using the root mean square (RMS) principle and combined with amplitude weighting, the method corrects the imaging results. Compared with the Ray-based full-matrix capture and TFM method (Ray-based FMC/TFM), the RMS-based full-matrix capture and TFM (RMS-based FMC/TFM), and the phase shift method, the experimental and simulation results demonstrate that the proposed method significantly reduces the imaging data volume, improves computational efficiency, and maintains quantitative errors within 0.2 mm.
Ultrafast and highly sensitive detection of SARS-CoV-2 spike protein by field-effect transistor graphene-based biosensors
Authors: Sousa Thiago A S L , Almeida Nathalie B F , Santos Fabrício A , Filgueiras Priscilla S , Corsini Camila A , Lacerda Camila M S , Silva Thais G , Grenfell Rafaella F Q , Plentz Flavio
Published: July 2024

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), etiological agent for the coronavirus disease 2019 (COVID-19), has resulted in over 775 million global infections. Early diagnosis remains pivotal for effective epidemiological surveillance despite the availability of vaccines. Antigen-based assays are advantageous for early COVID-19 detection due to their simplicity, cost-effectiveness, and suitability for point-of-care testing (PoCT). This study introduces a graphene field-effect transistor-based biosensor designed for high sensitivity and rapid response to the SARS-CoV-2 spike protein. By functionalizing graphene with monoclonal antibodies and applying short-duration gate voltage pulses, we achieve selective detection of the viral spike protein in human serum within 100 µs and at concentrations as low as 1 fg ml−1, equivalent to 8 antigen molecules per µl of blood. Furthermore, the biosensor estimates spike protein concentrations in serum from COVID-19 patients. Our platform demonstrates potential for next-generation PoCT antigen assays, promising fast and sensitive diagnostics for COVID-19 and other infectious diseases.
Enhanced polarization and endurance properties of ZrO2-based ferroelectric capacitor using HfO2 interfacial layer
Authors: Zhang Wei , Shi Yuxuan , Zhang Bowen , Liu Zengqiang , Cao Yating , Pan Ting , Li Yubao
Published: July 2024

Recently discovered ferroelectricity in fluorite-structure ZrO2 thin film has attracted increasing and intense interest due to its lower crystallization temperature and higher content in nature in comparison to hafnium oxide. Here, the effect of HfO2 interfacial layer on the ferroelectric properties of ZrO2 thin films is investigated systematically by designing four types of interfacial structures. It is revealed that the ferroelectric orthorhombic phase, remanent polarization, and endurance can be improved in ZrO2 thin film by inserting both a top- and bottom-HfO2 interfacial layer. A maximal ferroelectric remanent polarization (2P
r) of 53.4 μC cm−2 and an optimal endurance performance of 3 × 107 field cycles under frequency of 100 kHz are achieved in Pt/HfO2/ZrO2/HfO2/Pt capacitors, with ferroelectric stacks being crystallized at 450 °C via post-deposition annealing method. X-ray photoelectron spectroscopy analysis confirms that the HfO2 bottom-layer plays a very important role in the formation of a higher ratio o-phase, thus enhancing the ferroelectricity. These results suggest that designing appropriate interfaces would help achieve excellent ferroelectric properties in ZrO2 films.
Response and resilience of carbon nanotube micropillars to shear flow
Authors: Julien Brandon N , Jeon Minae , Geranfar Erfan , Ghode Rohit G S , Boutilier Michael S H
Published: July 2024

Interactions between carbon nanotubes (CNTs) and fluid flows are central to the operation of several emerging nanotechnologies. In this paper, we explore the fluid-structure interaction of CNT micropillars in wall-bounded shear flows, relevant to recently developed microscale wall shear stress sensors. We monitor the deformation of CNT micropillars in channel flow as the flow rate and wall shear stress are gradually varied. We quantify how the micropillars bend at low wall shear stress, and then will commonly tilt abruptly from their base above a threshold wall shear stress, which is attributed to the lower density of the micropillars in this region. Some micropillars are observed to flutter rapidly between a vertical and horizontal position around this threshold wall shear stress, before settling to a tilted position as wall shear stress increases further. Tilted micropillars are found to kink sharply near their base, similar to the observed buckling near the base of CNT micropillars in compression. Upon reducing the flow rate, micropillars are found to fully recover from a near horizontal position to a near vertical position, even with repeated on–off cycling. At sufficiently high wall shear stress, the micropillars were found to detach at the catalyst particle-substrate interface. The mechanical response of CNT micropillars in airflow revealed by this study provides a basis for future development efforts and the accurate simulation of CNT micropillar wall shear stress sensors.
III-V material-based junction-free L-shaped gate normal line tunneling FET for improved performance
Authors: Anam Aadil , Amin S Intekhab , Prasad Dinesh
Published: July 2024

In this paper, we introduce a novel III–V compound material-based junction-free (JF) L-shaped gate normal line tunneling field-effect transistor (III–V JF L GNLTFET) for improved output performance at 0.5 V operation. The key design metric, i.e. JF or junctionless design, in our device eliminates issues like random dopant fluctuations (RDF) and high thermal budgets and streamlines the fabrication. The implementation of III–V compound material, i.e. low bandgap compound GaSb, in the source region, combined with the larger area gate normal line tunneling, improves the ON current for our proposed III–V JF L GNLTFET device. Additionally, the utilization of large bandgap GaAs compounds on the drain and channel sides eliminates ambipolarity and further enhances the performance of our proposed device. Meaning that the proposed device simultaneously improves the ON current and suppresses the ambipolarity. Our proposed III–V JF L GNLTFET exhibits enhanced output performance with an ON current of 23.2 μA μm−1 and a minimum and average subthreshold swing of 3.7 mV dec−1 and 15.82 mV dec−1 respectively. Furthermore, the proposed III–V JF L GNLTFET also gives superior RF/analog performance with transconductance (168.65 μS), cut-off frequency (33.52 GHz), gain-bandwidth product (5.11 GHz), and transconductance-frequency product (243.7 GHz).
Intensive study on gamma-irradiated PVA/FeCl3/NiO nanocomposites for promising applications: structural, optical and electrical
Authors: Zaghlool R A , ElShawadfy S R , Mohamed F , Abdel Moghny A S
Published: July 2024

Tuning the optical parameters as well as the electrical conductivity of polymer composites is required to match the needs of optical and/or electrolyte-based energy storage devices. Depending on the choice of filler, the addition of small amounts of inorganic fillers to suitable polymers allows this target to be attained. In the present study, polyvinyl alcohol (PVA)/FeCl3/xNiO nanocomposites were prepared using the solution cast method. The structural, optical and electrical properties were investigated before and after irradiating the nanocomposites with gamma radiation at two doses, 300 and 400 Gy. Fourier transform infrared analysis confirmed the interaction of NiO with the PVA/FeCl3 matrix. The nanocomposites show a direct band gap that decreases from 2.47 to 2.25 eV as the NiO content increases from 0% to 7%, while the dc conductivity is increased from 9.15 × 10−8 to 8.46 × 10−7 S cm−1. After irradiation by 400 Gy of gamma radiation, the band gap of the PVA/ FeCl3/7%NiO nanocomposite is increased to 2.33 eV while the dc conductivity decreases to 1.19 × 10−8 S cm−1. On the other hand, the PVA/FeCl3 matrix shows low refractive index, 1.134 at 550 nm, which further increases to 1.213 as the NiO content reaches 7 wt%; this is reduced to 1.211 after exposure to 300 Gy of gamma radiation.
A novel numerical approach for analyzing experimental data on critical current degradation in Nb3Sn wires caused by transverse deformations preceding heat treatment
Authors: Burioli S , Iannone G , De Marzi G , D’Agostino D , Avallone G , Gagno A , Bracco M , Leveratto A , Traverso A , Pedrini D , Valente R , Prioli M , Piccardo P , Malagoli A , Farinon S , Musenich R
Published: July 2024

In the framework of studies on high-field magnets for future accelerators, a specific project called ASTRACT focuses on the effect of transverse strain on the critical current of Nb3Sn wires. The first phase of the project addresses the effects of strain imposed on Nb3Sn wires before heat treatment and the development of a procedure to directly compare critical current measurements with values extracted from magnetization cycles. A Nb3Sn RRP-Ti wire was deformed to different values of transverse strain (10%, 15%, 20%, and 25%), and long samples were collected for transport measurements at 4.2 K, in a background field ranging from 10 to 14 T. Short samples were used for magnetization measurements (VSM technique). Additionally, SEM images of the cross-section were collected at different longitudinal positions along the wire for each strain value. This paper proposes a method based on SEM image analysis and magnetization measurements analysis to study the effect of bundle deformation on transport properties. The procedure requires morphological information provided by SEM images after appropriate numerical processing. Verification through statistical comparison between the Ic transport and VSM data is also conducted. Direct critical current measurements showed no degradation due to deformation up to 25%. The method introduced, independent of transport data, can reach the same conclusions by considering the real shape of the bundles.
Enhancing the magnetic field gradient between two superconductors with rotational motion under a background DC field
Authors: Houbart M , Fagnard J-F , Harmeling P , Dular J , Dennis A R , Namburi D K , Durrell J H , Geuzaine C , Vanderheyden B , Vanderbemden P
Published: July 2024

The ability of bulk high-temperature superconductors to trap magnetic flux densities up to one order of magnitude larger than the saturation magnetization of conventional ferromagnetic materials offers the prospect of generating large magnetic flux density gradients. Combining multiple superconductors, akin to assembling a Halbach array of permanent magnets, may increase the generated gradient even further. The associated challenge is that superconductors are prone to demagnetization when exposed to field components perpendicular to their main magnetization direction. In the present work, we investigate the magnetic flux density gradient achieved with a pair of cubic, bulk, large-grain melt-textured superconductors in the presence of a background DC magnetic field at 77 K. We investigate the increase of the performance when decreasing the temperature down to 59 K. The studied configuration consists in two facing cubic YBa2Cu3O

7
−
x

superconductors of 6 mm side with anti-parallel magnetization directions. It is obtained after the simultaneous magnetization of the samples followed by a rotation of 180∘ of the top superconductor. Although the background field reduces the trapped field ability of individual samples, it is shown that this phenomenon is significantly mitigated at 65 K and at 59 K compared to 77 K. The results reveal that a sample-to-sample distance (

∼

16

mm) of the order of their size is sufficient to avoid any mutual demagnetization effect during the rotational motion. Furthermore, it is shown that decreasing the temperature is not only beneficial in increasing the field and field gradient achieved but also in extending the range of background fields in which the superconductor can be rotated without demagnetization. This superconducting assembly yields a magnetic flux density gradient exceeding that of an isolated superconductor and has the potential to surpass the capabilities of permanent magnets.
Understanding different oxidation methods for the hole transport layer Spiro-OMeTAD to improve perovskite solar cell performance
Authors: Chen Xinyao , He Linfeng , Zhang Chunqian , Cheng Jin , Liu Yuan , Li Junming
Published: July 2024

The preparation of a high-performance hole transport layer is a pivotal factor in achieving efficiency and stable perovskite solar cells. 2,2’,7,7’-Tetrakis[N, N-di(4-methoxyphenyl)amino]−9,9’-spirobifluorene (Spiro-OMeTAD) currently stands as the most widely employed hole transport material in high-performance perovskite solar cells. The current methodologies for its preparation primarily revolve around three techniques: O2 oxidation, cobalt salt doping, and CO2 bubbled doping. In this study, we systematically investigated and analyzed Spiro-OMeTAD prepared through these three methods, from solution and film to device. The CO2-bubbled method and Co-doped method allow for faster and more complete oxidation of Spiro-OMeTAD while maintaining conductivity and energy level matching. Therefore, the film of both methods shows better carrier extract capabilities and defect states than that of O2-oxidized. In particular, the film of the CO2-bubbled method had better hydrophobicity and thermal stability, showing the least degradation at 85 °C annealing, which can be attributed to the removal of hydrophilic Li+. This study could inspire further optimization of Spiro-OMeTAD film fabrication processes in perovskite solar cells.
Numerical simulation of arc stabilizing cycle in vacuum arc remelting of titanium alloy
Authors: Li Mingyu , Jia Lei , Miao Qingdong , Liu Wei , Zhao Peng , Yang Shufeng
Published: July 2024

Through utilizing numerical simulation methods, the flow state of the molten pool during the vacuum self-consumption melting process of titanium alloy was analyzed. The influence of the stable arc cycle on the shape of the molten pool, dendrite arm spacing, surface quality, and shrinkage cavity was examined. The results showed that without an external magnetic field, the molten pool for smelting a Φ720 mm specification titanium alloy ingot is dominated by self-inductance magnetic force, leading to a downward flow in the central part of the melt. A mere 0.5 G stray magnetic field can result in Ekman pumping, causing an upward secondary flow in the core to counteract it. At an externally added magnetic field strength of 50 G, choosing a 10 s-20 s cycle can achieve a relatively stable double loop flow pattern. The shape of its molten pool, dendrite arm spacing, and contact ratio all reach optimal performance, thus verifying the possibility and feasibility of the double loop flow, and the macroscopic segregation of the simulated ingots essentially matches the experimental results, aiming to provide references for selecting parameters in actual production.
Accretion onto oscillating cosmic string loops
Authors: Jiao Hao , Cyr Bryce , Brandenberger Robert
Published: July 2024

Cosmic string loops are non-linear density fluctuations which form in the early universe and could play an important role in explaining many phenomena which are in tension with the standard ΛCDM model. Hence, the accretion process onto cosmic string loops should be studied in detail. Most previous works view loops as point masses and ignore the impact of a finite loop size. In this work, we utilize the Zel'dovich approximation to calculate the non-linear mass sourced by a static extended loop with a time-averaged density profile derived from the trajectory of the loop oscillation, and compare the result with what is obtained for a point-mass source. We find that the finite size of a loop mainly affects the evolution of turnaround shells during the early stages of accretion, converging to the point mass result after a critical redshift, zc
( II)/( III). For zc
( II)/( III), the total accreted mass surrounding a loop is suppressed relative to the point mass case and has a growth rate proportional to (1+z)-3/2.
As an immediate extension, we also qualitatively analyse the accretion onto moving point masses and onto moving extended loops. In addition to the reduction in the nonlinear mass, the loop finite size also changes the shape of the turnaround surface at early stages of accretion.
Searching for QPOs in BATSE short gamma-ray bursts based on narrowband and broadband features
Authors: Liu Dong-Jie , Zou Yuan-Chuan
Published: July 2024

Gamma-ray bursts (GRBs), especially short GRBs, are often considered potential candidates for exhibiting kilohertz quasi-periodic oscillations (QPOs) due to their origin from binary mergers. It has already been discovered that two bursts exhibit QPOs. While systematic searches for QPOs in GRBs typically concentrate on the kilohertz range, there has been no comprehensive exploration in the hundred-hertz range. In this study, we systematically conducted QPO searches on all BATSE short burst data within the 0-1000 Hz range. Using nested significance tests, we observed that the reference distributions for different GRBs are quite similar. This observation prompted us to analyze the data by selectively focusing on those with larger statistical values, obviating the need to iterate through all the data and significantly reducing computational workload. Ultimately, our findings did not reveal any compelling evidence for QPOs, which may suggest that the GRB jet has lost the early merging memory.
Observational test of ℛ2spacetimes with the S2 star in the Milky Way galactic center
Authors: Yan Jian-Ming , Zhu Tao , Azreg-Aïnou Mustapha , Jamil Mubasher , Nguyen Hoang Ky
Published: July 2024

A novel class of vacuum metrics expressible in analytical form was recently found for pure ℛ2gravity, based on a groundwork put forth by Buchdahl in 1962. These Buchdahl-inspired solutions offer a practical framework for testing ℛ2gravity through empirical observations. Within a subclass of asymptotically flat Buchdahl-inspired vacuum spacetimes, we identified a parameter ϵ measuring the deviation from the classic Schwarzschild metric, which corresponds to ϵ=0. In this paper, we employ observational data from the S2 star's orbit around Sgr A* in the Milky Way galactic center and perform Monte Carlo Markov Chain simulations to probe the effects of the new metrics on the orbit of the S2 star. Our analysis presented herein reports a range at 95% confidence level on the deviation parameter as ϵ ∈ (-0.6690, 0.4452). While no decisive evidence either in favor or in disfavor of the asymptotically flat Buchdahl-inspired spacetimes has been achieved, the obtained bound is compatible with the tighter results using other data of different nature as recently reported inEur. Phys. J. C84(2024) 330. As a meaningful test probing into a strong-field regime, our present study calls for further observations with prolonged period and improved accuracy in order to tighten the bound for ϵ using the S2 star orbit.
Enhanced curvature perturbation and primordial black hole formation in two-stage inflation with a break
Authors: Wang Xinpeng , Zhang Ying-li , Sasaki Misao
Published: July 2024

We investigate a model of R2-gravity with a non-minimally coupled scalar field that gives rise to two-stage inflation with a break, that is, with an intermediate stage where inflation momentarily halts. We find that the power spectrum of the primordial curvature perturbation is significantly enhanced at the break scale, which can account for the primordial black hole (PBH) formation, without affecting the CMB constraint on large scales. The behavior of the curvature perturbation is carefully analyzed and we find a few notable new features in the spectrum. In particular, we find that the k3growth of the spectrum of toward the end of the first stage of inflation. We argue that this is a universal feature common to all two-stage models where the field dominating the second stage is heavy during the first stage. By appropriately tuning the model parameters, we find that our model can realize the scenario of PBHs as the cold dark matter of the Universe. We also find that we can choose the parameters so that the spectrum of the induced gravitational waves from the enhanced curvature perturbation fits the NANOGrav-15yr data of pulsar timing array observation.
Simulation study of multi-layer titanium nitride nanodisk broadband solar absorber and thermal emitter
Authors: Huang Xi , Yi Yingting , Song Qianju , Yi Zao , Ma Can , Tang Chaojun , Zeng Qingdong , Cheng Shubo , Raza Rizwan
Published: July 2024

Solar energy has always been a kind of energy with large reserves and wide application. It is well utilized through solar absorbers. In our study, the finite difference time domain method (FDTD) is used to simulate the absorber composed of refractory metal materials, and its absorption performance and thermal emission performance are obtained. The ultra-wide band of 200 nm–3000 nm reaches 95.93% absorption efficiency, of which the bandwidth absorption efficiency of 2533 nm (200 nm–2733 nm) is greater than 90%. The absorption efficiency in the whole spectrum range (200 nm–2733 nm) is 97.17% on average. The multilayer nanodisk structure of the absorber allows it to undergo strong surface plasmon resonance and near-field coupling when irradiated by incident light. The thermal emission performance of the absorber enables it to also be applied to the thermal emitter. The thermal emission efficiency of 95.37% can be achieved at a high temperature of up to 1500 K. Moreover, the changes of polarization and incident angle do not cause significant changes in absorption. Under the gradual change of polarization angle (0°–90°), the absorption spectrum maintains a high degree of consistency. As the incident angle increases from 0° to 60°, there is still 85% absorption efficiency. The high absorption efficiency and excellent thermal radiation intensity of ultra-wideband enable it to be deeply used in energy absorption and conversion applications.
On examining the predictive capabilities of two variants of the PINN in validating localized wave solutions in the generalized nonlinear Schrödinger equation
Authors: Thulasidharan K , Sinthuja N , Priya N Vishnu , Senthilvelan M
Published: July 2024

We introduce a novel neural network structure called strongly constrained theory-guided neural network (SCTgNN), to investigate the behaviour of the localized solutions of the generalized nonlinear Schrödinger (NLS) equation. This equation comprises four physically significant nonlinear evolution equations, namely, the NLS, Hirota, Lakshmanan–Porsezian–Daniel and fifth-order NLS equations. The generalized NLS equation demonstrates nonlinear effects up to quintic order, indicating rich and complex dynamics in various fields of physics. By combining concepts from the physics-informed neural network and theory-guided neural network (TgNN) models, the SCTgNN aims to enhance our understanding of complex phenomena, particularly within nonlinear systems that defy conventional patterns. To begin, we employ the TgNN method to predict the behaviour of localized waves, including solitons, rogue waves and breathers, within the generalized NLS equation. We then use the SCTgNN to predict the aforementioned localized solutions and calculate the mean square errors in both the SCTgNN and TgNN in predicting these three localized solutions. Our findings reveal that both models excel in understanding complex behaviour and provide predictions across a wide variety of situations.
Comparison of photon interaction coefficients for tumor compositions and healthy tissues simulated by Monte Carlo
Authors: Bozkurt Ahmet , Sengul Aycan
Published: July 2024

This study compares interaction coefficients of photons
(namely, mass attenuation, energy absorption and energy transfer
coefficients) for some tumor tissues with simlar healthy
tissues. Monte Carlo calculations were performed for adenoidcystic
carcinoma, melanoma, rectal adenocarcinoma, sarcoma and squamous
cell lung carcinoma. The simulation model involved a monoenergetic
point source producing a pencil beam. Depending on the parameter
under study, average flux, energy flux, or dose deposition from
photons that travels in an absorber were scored in the range of
10 keV–20 MeV energy using MCNP6.1. The same model was used to
compute the interaction coefficients of health tissues (namely,
gastrointestinal tract-small intestine wall, lungs-parenchyma,
salivary glands, skin, soft tissue (female+male)) for comparison
purposes. The results showed that, depending on the contents of the
tumor samples, photon interaction coefficients of a tumor may differ
from those of a similar healthy tissue. This behavior was distinct,
especially for energies up to 100 keV, and was attributed to the
presence of relatively higher atomic number elements in the
absorber.
A universal framework for entanglement detection under group symmetry
Authors: Park Sang-Jun , Jung Yeong-Gwang , Park Jeongeun , Youn Sang-Gyun
Published: July 2024

One of the fundamental questions in quantum information theory is determining entanglement of quantum states, which is generally an NP-hard problem. In this paper, we prove that all PPT

(

π
―

A

⊗

π
B

)

-invariant quantum states are separable if and only if all extremal unital positive

(

π
B

,

π
A

)

-covariant maps are decomposable where

π
A

,

π
B

are unitary representations of a compact group and π

A
is irreducible. Moreover, an extremal unital positive

(

π
B

,

π
A

)

-covariant map

L

is decomposable if and only if

L

is completely positive or completely copositive. We then apply these results to prove that all PPT quantum channels of the form

Φ

(
ρ
)

=
a

Tr

(
ρ
)

d

Id
d

+
b
ρ
+
c

ρ
T

+

(
1
−
a
−
b
−
c
)

diag

(
ρ
)

are entanglement-breaking, and that there is no A-BC PPT-entangled

(
U
⊗

U
―

⊗
U
)

-invariant tripartite quantum state. The former strengthens some conclusions in (Vollbrecht and Werner 2001 Phys. Rev. A 64 062307; Kopszak et al 2020 J. Phys. A: Math. Theor.
53 395306), and the latter resolves some open questions raised in (Collins et al 2018 Linear Algebra Appl.
555 398–411).
R.G. Collingwood
Authors: Ridley Aaron
Published: July 2024

Collingwood’s philosophy of art is usually wheeled out for target-practice, as a handy source of indefensible views and arguments. But this version of Collingwood is a straw man. The present essay is about the real Collingwood. Starting from his claim that ‘Art is the community’s medicine for the worst disease of mind, the corruption of consciousness’, it attempts to understand his philosophy of art in the ethical terms in which he himself intended it. This focus allows one to make better sense of his art/craft distinction, of his repudiation of the so-called ‘Ideal’ theory of art (a theory with which the straw-man version of him is still routinely saddled), of his claim that art is expression, and, indeed, of why he wrote The Principles of Art with such a sense of urgency in 1938.
Making Art, Making Craft
Authors: Ridley Aaron
Published: July 2024

Collingwood identifies six features that he holds to be characteristic of craft, features in terms of which, he says, the ‘technical theory of art’ mistakenly understands art-making. This essay attempts to locate the real source of the technical theory’s (alleged) mistake; and it concludes that two of Collingwood’s craft-features—among the least discussed of them, as it happens—are indeed incompatible with art-status, at any rate as Collingwood construes it. This conclusion is then made more concrete through a discussion of conceptual art, which shows why Collingwood would have to say that the ‘artistry’ involved in producing such art is really just a variety of craftsmanship. The essay ends on a sceptical note—not about that result in particular, but about the negative essentialism that underpins the Collingwoodian route towards it.
Bad Art
Authors: Ridley Aaron
Published: July 2024

Under what conditions do cases of artistic badness matter? When, if ever, is it appropriate to respond to them with indignation (as we might respond, for example, to certain cases of moral badness), and when with a dismissive shrug? This essay attempts to answer those questions by way of a number of case studies, including music by Nietzsche and Mozart, and a painting by Edward Burne-Jones. The conclusion is that, although sometimes misplaced, the active denunciation of bad art may be not merely appropriate, but essential, and that the reasons for this are distinctively aesthetic reasons, and not just moral ones in disguise. Special mention is reserved for those who lament the general decline of aesthetic culture—in this age or any other.
Critical Conversions
Authors: Ridley Aaron
Published: July 2024

‘My judgement is my judgement’, said Nietzsche; ‘no one else is easily entitled to it.’ This essay asks what it is to be entitled to a critical judgement as one’s own; and its answer is that, in confronting and responding to a work of art, and in trying to capture something of that response in words, the critic must (i) attempt to do justice to the work, (ii) attempt to do justice to his experience of the work and (iii) attempt, in articulating his experience, to order and negotiate between the various values by which that experience is informed. The great majority of the essay is devoted to an exploration of conditions (i), (ii) and (iii).
Mackie’s Arguments for Error Theory
Authors: Joyce Richard
Published: July 2024

Moral error theory is a form of skepticism about morality, according to which when people make moral judgments (e.g., “Stealing is morally wrong”), although they purport to say true things about the world, in fact the world does not contain the properties or relations that would be necessary to render any of these judgments true. This chapter introduces this view and outlines the case offered in its support by J. L. Mackie in his well-known 1977 book Ethics: Inventing Right and Wrong. Mackie’s arguments for moral error theory include the Argument from Diversity, the Argument from Strangeness, and the Argument from Objectification. The chapter does not aim in particular to defend these arguments, but analyzes them in turn while emphasizing that they are intended to work in conjunction with each other, building a case for moral skepticism. Mackie’s attempt to establish error theory is shown, ultimately, to be inconclusive.
Defenses of Moral Error Theory
Authors: Joyce Richard
Published: July 2024

This chapter runs through several arguments that have been mounted against moral error theory. (1) It is incoherent to class all moral judgments as false, because if it false that φ is morally prohibited then φ must be morally permissible. (2) The moral error theorist must hold that love is a mistake. (3) The companions in guilt argument: if there are no moral reasons, then there would be no epistemological reasons either, but that would be absurd. (4) The moral error theorist is on a slippery slope to rejecting all normative claims. (5) The challenge from Moorean epistemology: we are more confident of certain basic moral claims than we are in any argument offered by a moral skeptic. (6) The moral indispensability argument: moral facts are essential to our lives and thus we must accept them into our ontology. It is argued that all six of these objections fail.
Ancient African Religions
Authors: Baum Robert M
Published: July 2024

This book is the first continent-wide history of ancient African religions, focused on indigenous religions. Drawing on archaeological, linguistic, written, and oral sources, this work examines the history of ancient religions from the Paleolithic Age to the first Muslims in Africa. It begins with an examination of the earliest burial sites, associated with Homo naledi in South Africa, and analyzes the earliest archaeological evidence of ritual activity, funerals, and symbolic artifacts. It discusses the impact of the Neolithic Revolution on African religions, as well as the rise of the earliest African kingdoms and priesthoods. It places the rise of ancient Egyptian religious traditions within its African context, seeing it as both a product of African religious influences and a source of Mediterranean and Southwest Asian influences. It discusses the rise of iron-working technologies and blacksmith cults, particularly in Eastern Africa but also in iron-working cultures in West Africa. It discusses the importance of the Egyptian religious reform movement led by Akhenaten, as well as the rise of Axum in the Ethiopian highlands. Finally, it looks at the impact of Assyrian, Persian, Greek, and Roman conquests on the religious experiences of the peoples of northern and northeastern Africa.
Before Adam and Eve
Authors: Baum Robert M
Published: July 2024

This chapter examines the history of African religions from the early hominids to the unification of ancient Egypt. It stipulates a definition of religion that applies to Paleolithic and Neolithic traditions on the continent. It relies primarily on archaeological evidence and historical linguistics, given the absence of written sources prior to the late fourth millennium bce. Discussions of Paleolithic religions focus on burial sites, the use of ocher, and the ritual sites of the Tsodilo Hills of Botswana. Discussion of Neolithic religious practice continues through the analysis of burial sites, including the positioning of bodies and the growing diversity of objects placed in the graves. Rock art provides evidence of ancient Saharan cattle and ram cults, while the Nile Valley’s widespread falcon cult may have provided a religious basis for the unification of Egypt. Linguistic evidence suggests a widespread concept of a supreme being in areas where Niger-Congo languages were spoken.
North and Northeast Africa in the Age of Roman and Byzantine Domination
Authors: Baum Robert M
Published: July 2024

Throughout this region, Christians encountered well-entrenched followers of traditional religions that remained viable into the sixth century. In North Africa, Carthaginian and Amazigh traditions were influenced by Egyptian, Greek, and Roman practices before widespread conversion beginning in the third century. North Africa became a center of Orthodoxy (Tertullian and Augustine) as well as a source of resistance to the dominant churches (Circumcellions and Arians). Nubia remained a center of a traditional religion, heavily influenced by Egyptian religions, until it became predominantly Monophysite. Axum continued the practice of traditional religion until the reign of Ezana.
Conclusion
Authors: Baum Robert M
Published: July 2024

This chapter emphasizes the feasibility of writing a history of ancient African religions by relying primarily on archaeology and historical linguistics, with a gradually increasing number of oral traditions and written sources. The earliest evidence of religious activity concerns the ritual disposition of the dead and early ritual sites. Historical linguistics offer the earliest evidence of African religious thought. This study focuses primarily on those religious traditions created in Africa, but it does place them within the context of contact with non-African religions. Such influences begin with the Sabeans, Phoenicians, Greeks, and Hebrews and continue with the influence of Christianity in North and northeast Africa. African religious traditions remain the central focus.
Herb-CMap: a multimodal fusion framework for deciphering the mechanisms of action in traditional Chinese medicine using Suhuang antitussive capsule as a case study
Authors: Wang Yinyin , Sui Yihang , Yao Jiaqi , Jiang Hong , Tian Qimeng , Tang Yun , Ou Yongyu , Tang Jing , Tan Ninghua
Published: July 2024

Herbal medicines, particularly traditional Chinese medicines (TCMs), are a rich source of natural products with significant therapeutic potential. However, understanding their mechanisms of action is challenging due to the complexity of their multi-ingredient compositions. We introduced Herb-CMap, a multimodal fusion framework leveraging protein–protein interactions and herb-perturbed gene expression signatures. Utilizing a network-based heat diffusion algorithm, Herb-CMap creates a connectivity map linking herb perturbations to their therapeutic targets, thereby facilitating the prioritization of active ingredients. As a case study, we applied Herb-CMap to Suhuang antitussive capsule (Suhuang), a TCM formula used for treating cough variant asthma (CVA). Using in vivo rat models, our analysis established the transcriptomic signatures of Suhuang and identified its key compounds, such as quercetin and luteolin, and their target genes, including IL17A, PIK3CB, PIK3CD, AKT1, and TNF. These drug–target interactions inhibit the IL-17 signaling pathway and deactivate PI3K, AKT, and NF-κB, effectively reducing lung inflammation and alleviating CVA. The study demonstrates the efficacy of Herb-CMap in elucidating the molecular mechanisms of herbal medicines, offering valuable insights for advancing drug discovery in TCM.
An interpretable Bayesian clustering approach with feature selection for analyzing spatially resolved transcriptomics data
Authors: Li Huimin , Zhu Bencong , Jiang Xi , Guo Lei , Xie Yang , Xu Lin , Li Qiwei
Published: July 2024

Recent breakthroughs in spatially resolved transcriptomics (SRT) technologies have enabled comprehensive molecular characterization at the spot or cellular level while preserving spatial information. Cells are the fundamental building blocks of tissues, organized into distinct yet connected components. Although many non-spatial and spatial clustering approaches have been used to partition the entire region into mutually exclusive spatial domains based on the SRT high-dimensional molecular profile, most require an ad hoc selection of less interpretable dimensional-reduction techniques. To overcome this challenge, we propose a zero-inflated negative binomial mixture model to cluster spots or cells based on their molecular profiles. To increase interpretability, we employ a feature selection mechanism to provide a low-dimensional summary of the SRT molecular profile in terms of discriminating genes that shed light on the clustering result. We further incorporate the SRT geospatial profile via a Markov random field prior. We demonstrate how this joint modeling strategy improves clustering accuracy, compared with alternative state-of-the-art approaches, through simulation studies and 3 real data applications.
The clinical and pathological evaluation of patients with immunoglobulin A nephropathy by diffusion tensor imaging and intravoxel incoherent motion diffusion-weighted imaging
Authors: Zhou Huan , Si Yi , Yang Ling , Wang Yi , Xiao Yitian , Tang Yi , Qin Wei
Published: July 2024

Objectives

To explore the efficacy of diffuse magnetic resonance imaging (MRI) for identifying clinicopathological changes in immunoglobulin A nephropathy (IgAN) patients.

Methods

The study enrolled IgAN patients and healthy volunteers. IgAN patients were divided into Group 1 [estimated glomerular filtration rate (eGFR) ≥ 90 mL/min/1.73 m2], Group 2 (60 ≤ eGFR < 90 mL/min/1.73 m2), and Group 3 (eGFR < 60 mL/min/1.73 m2). Intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and diffusion tensor imaging (DTI) were performed via 3.0 T magnetic resonance. Diffuse MRI, clinical, and pathological indicators were collected and analysed. P < .05 was considered statistically significant.

Results

Forty-six IgAN patients and twenty-seven volunteers were enrolled. The apparent diffusion coefficient, diffusion coefficient (D), perfusion fraction (f), and fractional anisotropy (FA) were significantly different among IgAN subgroups and controls. These parameters were positively correlated with eGFR and negatively with creatinine, and inversely correlated with glomerular sclerosis, interstitial fibrosis, and tubular atrophy (all P < .05). They had significantly high area under the curve (AUC) for distinguishing IgAN patients from controls, while FA had the highest AUC in identifying Group 1 IgAN patients from volunteers.

Conclusions

DTI and IVIM-DWI had the advantage of evaluating clinical and pathological changes in IgAN patients. DTI was superior at distinguishing early IgAN patients and might be a noninvasive marker for screening early IgAN patients from healthy individuals.

Advances in knowledge

DTI and IVIM-DWI could evaluate clinical and pathological changes and correlated with Oxford classification in IgAN patients. They could also identify IgAN patients from healthy populations, while DTI had superiority in differentiating early IgAN patients.
Innovative approaches to atrial fibrillation prediction: should polygenic scores and machine learning be implemented in clinical practice?
Authors: Petzl Adrian M , Jabbour Gilbert , Cadrin-Tourigny Julia , Pürerfellner Helmut , Macle Laurent , Khairy Paul , Avram Robert , Tadros Rafik
Published: July 2024

Atrial fibrillation (AF) prediction and screening are of important clinical interest because of the potential to prevent serious adverse events. Devices capable of detecting short episodes of arrhythmia are now widely available. Although it has recently been suggested that some high-risk patients with AF detected on implantable devices may benefit from anticoagulation, long-term management remains challenging in lower-risk patients and in those with AF detected on monitors or wearable devices as the development of clinically meaningful arrhythmia burden in this group remains unknown. Identification and prediction of clinically relevant AF is therefore of unprecedented importance to the cardiologic community. Family history and underlying genetic markers are important risk factors for AF. Recent studies suggest a good predictive ability of polygenic risk scores, with a possible additive value to clinical AF prediction scores. Artificial intelligence, enabled by the exponentially increasing computing power and digital data sets, has gained traction in the past decade and is of increasing interest in AF prediction using a single or multiple lead sinus rhythm electrocardiogram. Integrating these novel approaches could help predict AF substrate severity, thereby potentially improving the effectiveness of AF screening and personalizing the management of patients presenting with conditions such as embolic stroke of undetermined source or subclinical AF. This review presents current evidence surrounding deep learning and polygenic risk scores in the prediction of incident AF and provides a futuristic outlook on possible ways of implementing these modalities into clinical practice, while considering current limitations and required areas of improvement.