bluuebunny/crossref_metadata_2025 huggingface dataset:
Single cell micro-absorption spectroscopy system with temperature control: System design and spectral analysis
Authors: Liu Yufei , Li Bo , Sun Yue , Li Changxu , Lu Fengya , Zhong Zhensheng , Zhou Jinhua , Xie Yingying , Zhang Shengzhao , Liang Zhen , Zhou Mei
Published: December 2024

Micro-absorption spectroscopy is a useful tool for studying the biological characteristics of single cells. However, the weak spectral signal, due to low absorption caused by the tiny optical path length of the cell, makes the spectral data noisy and difficult to analyze. This paper describes a device for single-cell microspectroscopy measurement that integrates an optical fiber spectrometer and an image CCD within a microscopic system, allowing for the simultaneous acquisition of morphology information and the absorption spectrum of a single cell. The device utilizes an illumination source driven by modulated current sources instead of constant current sources and the corresponding spectral signal extraction method to reduce noise levels. It also features a transparent temperature-controlled sample chamber for regulating the sample’s temperature, as the absorption of cells may change with temperature. Due to the unwanted baseline drift in the spectral signals, a method of analyzing the similarity degree between the measured spectrum and the standard spectrum is proposed to study the characteristic variation of cells. To verify the feasibility of this method, the device was used for the microscopic spectral measurement and analysis of single red blood cells. The results showed that the variation patterns of spectral parameters correspond to the cell's responses to changes in temperature and storage duration.
Numerical study of wake flow across two circular cylinders in tandem arrangement with high rotation speed
Authors: Siddiqui Muhammad Aneeb , Munir Adnan , Ali Muhammad Hamza , Zhao Ming , Duan Penghao , Qadri Muhammad Nafees Mumtaz
Published: December 2024

Flow behind a bluff body is marked with unstable wake pattern eventually impacting the forces acting on the body, which can be actively controlled by rotation. When multiple rotating bluff bodies are placed in close proximity, the wake flow and resulting forces are significantly affected by the mutual flow interaction, necessitating detailed analysis for practical applications. In this vein, this study investigates the variation in wake flow across two circular cylinders, placed in a tandem arrangement, for both co-rotation and counter-rotation configurations. Two-dimensional numerical simulations are performed at a low Reynolds number of 100 for three gap ratios of L/D = 1.5, 2, and 4, where L and D are the center-to-center distance between the cylinders and the cylinder diameter, respectively. The non-dimensional rotation rate is varied from 0 to 6 for the co-rotation configuration and the range is extended till 15 for counter-rotation configuration to capture the secondary instability regime of the system. Flow regimes and force coefficients are analyzed to qualitatively and quantitatively map the overall system behavior, respectively. The flow regimes observed for different rotation rates and L/D are noticed to be different combinations of the flow regimes observed for a single rotating cylinder. Irrespective of the co-rotation or counter-rotation configuration, the dominant frequency of secondary vortex shedding for both upstream and downstream cylinder is noticed to be same, indicating that either a single vortex is shed from the system or a synchronized vortex pair is shed with one vortex from each cylinder. Compared to the co-rotating cylinders, counter-rotating cylinders demonstrate predominant inclination toward steady flow behavior over majority of the studied rotation rates.
Optimization of the blow-off efficiency of kerosene adhering to the inner wall of chambers with complex structures
Authors: Jing Wenzheng , Xiang Min , Gao Qiang , Wu Feng
Published: December 2024

The research objective of this paper is to obtain an efficient space engine chamber wall adherent kerosene blow-off solution, the research methodology uses computational fluid dynamics method and experiments are conducted to verify the numerical calculation accuracy. The effect of gas pressure, gas temperature, ambient temperature, and gas type on the blow-off efficiency was obtained, in which increasing the pressure and temperature of the blow-off gas increased the treatment efficiency by 14.16% and 9.85%, respectively, and the blow-off efficiency was significantly improved. Increasing the operating ambient temperature and changing the type of purge gas increased the treatment efficiency by 4.76% and 5.88%, respectively. Finally, the removal scheme was optimized by increasing the blow-off gas pressure and temperature, and the treatment efficiency of the optimized scheme was improved by 37.5% compared to the original scheme. The findings of this paper provide important guidance for the efficient blow-off off of kerosene adhering to the inner wall of complex structural cavities.
Breeding objectives and economic value of important traits of Abergelle goats kept under a smallholder production system in Tigray, Ethiopia
Authors: Gebre Kahsa Tadel , Agegnehu Fasika , Teweldemedhn Tesfaye Gebreselama , Bariagabre Solomon Abera , Hagos Tsige Hailay
Published: December 2024

Context In developing countries, the production of livestock can be improved by establishing a functional breeding program that involves communities in planning and implementation. Production objectives, farmers’ preferences for traits, and the economic value of the traits need to be studied and documented in designing a functional breeding program. Aim This study aims to identify production objectives, determine the preferred traits of smallholder farmers, and estimate the economic values of important traits for Abergelle goats in Tigray, Ethiopia. Methods An own-flock ranking exercise was used to identify the trait preferences of smallholder farmers. A bio-economic model was employed to estimate the economic values of important traits of Abergelle goats. Key results Abergelle goats were mainly kept for income generation followed by milk production. Appearance (size), color, libido, pedigree, and growth were the most important breeding-buck attributes, whereas milk yield, mothering ability (kid survival and growth), pedigree, coat color, kidding interval, and twinning were the important attributes for breeding does. Positive economic values of €0.25, €0.12, €0.45, €0.68, €0.17 and €2.00 per genetic standard deviation were obtained for 6-month weight, mature weight, daily milk yield, liter size, kidding interval, and pre-weaning kid survival per average doe place and year respectively. However, a negative economic value of −€0.017 per genetic standard deviation was achieved for 3–6-month average daily gain (ADG) per doe per year. Conclusions In this study, the most economically significant traits with positive economic values were pre-weaning survival, litter size, daily milk yield, 6-month weight, mature weight, and kidding interval. Implication Including these traits in the breeding goals can increase the profitability of the flock and improve the livelihood of Abergelle goat keepers.
Somatic polyploidy supports biosynthesis and tissue function by increasing transcriptional output
Authors: Lessenger Alexander T. , Skotheim Jan M. , Swaffer Mathew P. , Feldman Jessica L.
Published: December 2024

Cell size and biosynthetic capacity generally increase with increased DNA content. Somatic polyploidy has therefore been proposed to be an adaptive strategy to increase cell size in specialized tissues with high biosynthetic demands. However, if and how DNA concentration limits cellular biosynthesis in vivo is not well understood. Here, we show that polyploidy in the Caenorhabditis elegans intestine is critical for cell growth and yolk biosynthesis, a central role of this organ. Artificially lowering the DNA/cytoplasm ratio by reducing polyploidization in the intestine gave rise to smaller cells with dilute mRNA. Highly expressed transcripts were more sensitive to this mRNA dilution, whereas lowly expressed genes were partially compensated—in part by loading more RNA Polymerase II on the remaining genomes. Polyploidy-deficient animals produced fewer and slower-growing offspring, consistent with reduced synthesis of highly expressed yolk proteins. DNA-dilute cells had normal total protein concentration, which we propose is achieved by increasing the expression of translational machinery at the expense of specialized, cell-type–specific proteins.
Amplitude stability research and experimental investigation of the actuation circuit of the inertial sensor for space gravitational wave detection
Authors: Zhang Jiawei , Yu Peilong , Lin Shuyang , Ma Qinbo , Han Zhe , Huang Jianping
Published: December 2024

The primary measure of scientific performance for inertial sensors used in space gravitational wave detection is the residual acceleration noise of the test mass (TM). This residual noise arises from both the internal circuit and the external environment. The actuation circuit, a crucial component of the internal circuit, significantly affects the TM’s residual acceleration noise through its amplitude stability, thereby impacting the scientific performance of the inertial sensor. In this study, we designed the actuation circuit for an inertial sensor, developed a mathematical model to describe its amplitude stability, and experimentally verified the model’s accuracy. Experimental results demonstrate that the current design enables the actuation circuit to achieve an amplitude stability of 3.6 ppm Hz−1/2 at 1 mHz, thereby offering theoretical support for achieving a higher amplitude stability in the millihertz frequency band.
Electrically controlled flexible and varifocal microlens array using liquid crystals on polymer
Authors: Panchal Rahul , Sinha Aloka
Published: December 2024

Microlens arrays (MLA) on flexible substrates have a wide range of applications in advancing curved integral imaging and three-dimensional (3D) display systems with a large field of view. We developed an electrically controlled varifocal MLA on flexible polyethylene terephthalate (PET) substrates by infiltrating liquid crystals (LC) in polymeric concave lenses. The focusing and imaging characteristics of the flexible LC-MLA are studied experimentally. When voltage is applied across the LC layer, the refractive index of the LC changes, which causes a change in the effective focal length of the MLA. The electrically tunable focal length and tunable focusing of the MLA are experimentally demonstrated. The mathematical analysis of the LC MLA is performed using the MATLAB platform. The presented flexible LC-MLA is developed using simple and cost-effective fabrication methods, which can potentially be used in future 3D displays and imaging solutions.
Vision-based weld detection and localization for climbing robots in large-scale storage tank inspections
Authors: Wang Ruifeng , Ma Nvjie , Xu Zhihao , Zhou Xuefeng , Pan Jia , Gu Shichao
Published: December 2024

Climbing robots are considered an effective solution for inspecting welds on the walls of large storage tanks. For these robotic systems, the efficient and accurate identification and localizing of weld seams are crucial prerequisites for ensuring precise weld seam tracking. In this paper, we investigate machine vision-based algorithms for feature recognition and localization of weld seams on tank walls for inspection of weld seams by a climbing robot. First, we designed the model of the image algorithm to extract the weld features of the tank walls. After extracting the weld features, we propose the novel idea of feature discretization and a Min-outer Rectangle Fitting Algorithm (MRFA), which will achieve the fitting of rectangular features on the discretized weld features. We constructed a mathematical model for calculating the orientation angle of the rectangular box based on the extracted rectangular boxes. This model allows for the real-time and efficient extraction of the rectangular feature’s pose information (x, y, θ). We also propose an efficient method for calculating the curvature of a curve trajectory. The experimental results demonstrate that the proposed image algorithm model and MRFA effectively identify weld features on the storage tank wall surface, while simultaneously achieving high-accuracy feature localization. Positioning errors are maintained within 3 mm for position and 3 degrees for azimuth, indicating both high precision and robustness. Additionally, the algorithm processes each image in approximately 80 milliseconds. The lightweight and efficient design of the proposed model allows it to be easily deployed on a climbing robot for weld seam detection and tracking on tank walls.
Design and control of radial electromagnetic bearing for flywheel battery
Authors: Sun Binbin , Meng Fantao , Wang Pengwei , Cheng Shuo , Feng Chao
Published: December 2024

The increase in rotational speed is the key to enhancing the energy storage capacity of flywheel batteries. Non-contact bearings can ensure reliable operation of high-speed flywheel batteries. To design electromagnetic bearings that meet the requirements of high-speed flywheel batteries. Firstly, a multi parameter and multi-objective optimization model for the radial electromagnetic bearing structure was designed with the optimization objectives of maximum electromagnetic force and minimum volume. On the basis of ensuring maximum electromagnetic force, the minimum spatial volume is reduced by 16.58%. Furthermore, the influence of bias current and control current on the electromagnetic force and rotor displacement of radial electromagnetic bearings was analyzed. The bias current and control current that satisfy the current stiffness and displacement stiffness were determined. Then, a mathematical model for differential control of radial magnetic bearings was constructed and a magnetic bearing controller based on adaptive discrete sliding mode control was designed. Finally, flywheel battery bench testing and data analysis were conducted. The results show that the designed radial magnetic bearing can achieve low response error, low system oscillation, and high robustness operation under the conditions of buoyancy step, foundation excitation, and random excitation. Compared with the sliding mode control method, the maximum difference in displacement tracking error was reduced by 62.31%, the average error was reduced by 42.74%, and the energy consumption was reduced by 49.32% under random excitation test conditions.
Nonradial symmetry and blow-up of ground states for a Schrödinger–Poisson system with logarithmic term
Authors: Wang Zhengping , Zeng Xiaoyu , Zhou Huan-Song
Published: December 2024

We consider the following Schrödinger–Poisson system

{

−
Δ
u
+
V

(
x
)

u
+
λ
ϕ

(
x
)

u
=
u
log

u
2

,
 
x
∈

ℝ
3

,

(0.1)

−
Δ
ϕ
=

u
2

,
 

lim

|
x
|
→
+
∞

ϕ

(
x
)

=
0
,

where

λ
∈

R

is a parameter,

V
∈
C
(

R

3

,

R

+

)

is a coercive potential. We prove that, if

V
(
x
)
∼
(
log
⁡

|

x

|

)

1
2

at infinity, then the energy functional I

λ
associated with (0.1) fails to be C
1, and there is

λ
0

>
0

such that (0.1) has a ground state

u
λ
0

for any

λ
∈
(
0
,

λ
0

)

, which blows up as

λ
→

0
+

, but if

V
(
x
)
=
V
(

|

x

|

)
∼
(
log
⁡

|

x

|

)

α

with

α
∈
(
0
,
1
)

at infinity, then there exists a sequence

λ
n

→

0
+

such that each

u

λ
n

0

must be non-radially symmetric. However, if V(x) grows like

|
x

|
γ

(γ > 0) at infinity, we show that the functional I

λ
is of C
1 and (0.1) has a ground state

u
λ
1

for each λ < 0 which is radially symmetric. Also, the limit behavior of

u
λ
1

as

λ
→

0

−

is discussed.
Multi-resonant TVA formed by a tree of deflated composite beams with core structured fabrics
Authors: Gardonio Paolo , Ortis Lisa , Rustighi Emiliano , Malacarne Ciro , Perini Matteo
Published: December 2024

This paper presents a study on a multi-resonant tuneable vibration absorber for the control of flexural vibrations of thin structures in a low frequency band where the response is characterized by distinct lightly damped resonances of low order flexural modes. The absorber is formed by a tree of deflated composite beams made by a core structured fabric wrapped on a plastic skin. The beams have increasingly smaller length and are fixed in the middle on a mast that works as a base-post and vacuum-junction too. The fabric in each beam is made by a lattice of interlocked truss-like rigid particles. The uniform pressure exerted by the deflated skin forces the particles to jam such that the fabric moves from its natural fluid-like state to a solid state whose rigidity depends on the confining pressure exerted by the skin. Hence, each beam is characterized by a fundamental flapping vibration mode whose response resembles that of a classical mass-spring-damper vibration absorber and can be suitably tuned by adjusting the level of vacuum. The paper first analyses the working principles of single-beam and three-beams absorbers with respect to their vibration transmissibility and base impedance frequency response functions. Then, it presents the vibration control generated by the single-beam and the three-beams absorbers tuned to minimise the resonant responses of a single or three low order flexural modes of a thin plate. The paper shows that the operational frequency of each beam-absorber can be suitably adapted in a band of 8 Hz by varying the vacuum pressure in a 5–80 kPa range. Also, it shows that the single-beam or multi-beams absorbers reduce the resonant response of the target flexural modes by 10–20 dB.
Dependence of water radiation on temperature at microwaves
Authors: Gavrilin S N
Published: December 2024

Extra experimental and calculated data are presented for the previously published work. The dependence of water thermal radiation from the water temperature was studied. The experiment was performed outdoors. A radiometer with central frequency 37,5 GHz (8 mm) was used. The increase of brightness temperature was 3 K in the water temperature range 30 °C–50 °C and about 25 K in the temperature range 55 °C–85 °C. The radio emission of water depends non-linearly on the kinetic temperature. It was measured that the radio brightness of the surface temperature increases from 0.28 to 1 K per 1 °C of water heating. The discrepancy between theoretical estimates and experimental data is noted. An explanation of the reasons for this discrepancy is offered.
Lattice Boltzmann method to simulate photocatalytic reduction of CO2 over PCN-601 coated on transparent porous substrate
Authors: Li Nannan , Zhan Hongwei , Tong Kai , Chen Zhidong , Kong Yanqiang , Yang Lijun , Du Xiaoze
Published: December 2024

Photocatalysis offers a promising approach to convert solar energy and CO2 into clean chemical energy, such as methane (CH4) and carbon monoxide (CO), contributing to carbon neutrality. This study proposes a lattice Boltzmann method to solve radiation transport within transparent porous substrates for photocatalytic CO2 reduction. Numerical simulations of mass transfer, radiation, and reaction kinetics are in good agreement with experimental results. The influence of triply periodic minimal surfaces (TPMS) as porous substrates on photocatalytic efficiency is investigated, identifying substrate thickness as the dominant variable affecting performance. At reduced thicknesses, porosity and surface area gain importance by enhancing light absorption and fluid flow. Notably, at 10 pores per inch (PPI), a 2 mm thick Schwarz D substrate demonstrates comparable photocatalytic performance to a 7 mm thick gyroid. However, at 30 PPI, it leads to diminished performance despite similar porosity by reducing thickness. These results suggest that a PPI value around 10 optimizes the efficiency for photocatalytic CO2 reduction.
Dispersive and attenuation behavior of Love wave in a non-local highly heterogeneous media with imperfect contact condition
Authors: Sadab Mohd , Kundu Santimoy
Published: December 2024

The primary aim of this study is to explore the impact of different physical parameters on the propagation of Love waves in non-local media. This study considers heterogeneous orthotropic viscoelastic properties within a layer and the variation of sandy medium properties with exponential depth, representing the half-space. Furthermore, the interface between the layer and the half-space is considered mechanically imperfect and perfect. The solutions of mechanical displacement of the layer and half-space are derived separately by solving the second-order hyperbolic type differential equation with the help of a variable-separable technique. A closed form of the dispersion relation is obtained using appropriate boundary conditions involving the medium’s non-local elasticity and inhomogeneity parameters. Verification of the dispersion relation is shown by deriving some particular cases and comparing them with the classical dispersion relation of Love wave. The effects of physical parameters (like viscoelasticity, inhomogeneity, interfacial imperfection, sandy, non-locality, and thickness of the layer) on the phase and attenuation phenomena of Love wave are investigated through numerical calculations and graphical representation. Furthermore, it is observed that the particle displacement in the layer decreases with depth, while in the half-space, the amplitude decreases oscillatory with depth, and the displacement gradually converges towards zero. A comparative graphical analysis of these parameters on the phase and attenuation characteristics of Love wave through the stratified Earth’s structure with imperfect and perfect interfaces has been accomplished.
Recent progress and development trends of oil wear particle detection sensors applied in marine machinery condition monitoring
Authors: Zhang Hongpeng , Han Wenbo , Bai Chenzhao , Li Wei , Wang Xin , Liu Yu
Published: December 2024

Oil wear particle can offer wear condition for marine machinery. The shape, size and composition of wear particle can supply important information for diagnosing the type and severity of marine machinery faults. Through oil wear particle detection, potential marine machinery fault diagnosis can be found early, thereby reducing the risk of marine machinery failure diagnosis and improving the reliability and service life of marine machinery. This review summarizes the detection methods, technical characteristics and research progress of oil wear particle detection sensors applied in marine machinery condition monitoring. Oil wear particle detection sensors are divided into impedance-based particle detection method and non-impedance-based particle detection method. Impedance-based method includes inductance, capacitance and resistance principles. Non-impedance-based method includes image processing, optical and acoustic principles. Finally, it points out the future development trends and novel ideas for the oil wear particle detection sensors employed in marine machinery.
On the singular position-dependent mass
Authors: Lima F C E , Belchior F M , Almeida C A S
Published: December 2024

Revisiting the issue associated with Position-Dependent Mass (PDM), we reaffirm that the appropriate framework for addressing a generic PDM is the symmetrization proposed by BenDaniel and Duke. To accomplish this result adopts the effective mass Hamiltonian proposed by von Roos, corrected by a symmetrized kinematic term. After verifying the appropriate ordering to approach the PDM issue, one investigates a crystalline lattice with a defect described by a singular PDM. The singular mass profile proves intriguing as it yields an atom’s cluster in the neighborhood of the singularity. Considering that a restoring force acts on the atoms, one notes that the confluent Heun function describes the quantum states. Furthermore, one highlights that when the effective mass distribution tends to a constant profile, we recover a system similar to the harmonic oscillator.
Tuning planar transverse domain wall dynamics in bilayer nanostructures using transverse magnetic fields, Rashba, and spin-Hall effects
Authors: Halder Ambalika , Maity Sumit , Dwivedi Sharad
Published: December 2024

This work deals with the tunability of a planar transverse domain wall with an arbitrary azimuthal angle, achieved by applying a transverse magnetic field of tunable strength and fixed orientation. To be precise, we investigate the static and dynamic features of a planar transverse domain wall within a bilayer nanostructure consisting of a ferromagnetic layer and a non-magnetic heavy metal layer, employing the Landau–Lifshitz-Gilbert equation as our theoretical framework. The domain wall dynamics are analyzed through the collective coordinate method and regular perturbation asymptotic approach, accounting for the combined effects of axial and transverse magnetic fields, spin-polarized electric currents, Rashba effect, and spin-Hall effect. Our study comprehensively analyses the planar transverse domain wall profile, characterized by sharply defined boundaries between adjacent domains and a precise distribution of the transverse magnetic field. In addition, we detail the linear polar angle distribution within the domain wall region, the capability to freely tune the domain wall width, and the enhanced domain wall velocity in steady-state regime. The analytical results are further numerically illustrated, offering valuable insights into manipulating and controlling domain wall dynamics.
Spin glass behavior of single-crystalline ErFe2O4−δ
Authors: Sihui Li , Konishi Shinya , Tanaka Katsuhisa
Published: December 2024

We investigated magnetic properties of ErFe2O4–δ
single crystal containing oxygen vacancies with value of δ being estimated to be 0.066. The temperature dependence of dc magnetization in zero field cooling (ZFC) process reveals that ErFe2O4–δ
undergoes a ferrimagnetic transition at 234 K followed by a broad peak at 224.3 K. The latter is attributable to the spin glass transition as indicated by the strong frequency dependence of temperature-dependent ac susceptibility. The frequency variation of transition temperature is described well by the dynamic scaling law and the critical exponent is similar to those reported for typical spin glasses. Additionally, the spin glass transition at 224.3 K is confirmed by the fact that the magnetic field dependence of irreversible transition temperature is coincident with the de Almeida-Thouless line and that the aging memory and rejuvenation effect is observed. Noticeably, ErFe2O4−δ
single crystal exhibits the field-cooled hysteresis loop shift and training effect below 200 K, suggesting the occurrence of exchange bias effect originating from the spin glass phase.
Numerical study of minority ion heating scenarios in CN-H1 stellarator plasma
Authors: Wang Shuangshuang , Yin Lan , Chen You , Gong Xueyu , Peng Yaoyi , Zheng Pingwei , Ma Wankun , Ou Qi
Published: December 2024

A preliminary simulation of ion cyclotron resonance heating (ICRH) in the poloidal cross-section at the antenna location of the CN-H1 (Chinese Heliac 1) stellarator has been conducted for the first time using the full-wave solver TORIC. The heating scheme employed focuses on minority ion heating of He4 (H), with an independent investigation into the effects of wave frequency, toroidal mode number, and minority ion concentration on ICRH. Preliminary simulation results indicate that, under the conditions of wave frequency f = 4.7MHz, central magnetic field B
0 = 0.32T and low-temperature, low-density plasma (with density on the order of 1018 m−3 and temperature in the range of tens of eV), more efficient minority-ion heating can be achieved when the toroidal mode number is in the range of 10–20 and the minority ion concentration is between 15% and 30%. This simulation provides theoretical insights and delineates the parameter space for prospective ICRH experiments in CN-H1.
An analytical model for dispersion relation of parallel plate Waveguide with periodic metallic cylinder nails
Authors: Mai Huanxiao , Liu Xiaobo
Published: December 2024

In this letter, a novel analytical model for a parallel plate waveguide composed of periodic metallic cylinder nails is developped, which is especially effective for sparse nails at higher frequencies. Based on the proposed model, one can effectively and precisely derive the dispersion relation of parallel plate Waveguide with the periodic metallic cylinder nails.The waveguide is modeled as a transmission line with periodically loaded parallel impedances. These impedances correspond to the periodic metallic cylinder nails arranged in a plane perpendicular to the propagation direction. To solve for the parallel impedance, the mirror principle is employed to extend the periodic metallic cylinder nails into the full space. Subsequently, based on the current distribution on the metallic nails, Fourier transformation and Poisson summation techniques are utilized to express the radiated field in terms of multiple Floquet modes. The boundary condition for the metallic nails is then applied to derive the analytical expression for the parallel impedance. Simulation results strongly support the proposed theory. Notably, the transmission line theory stipulates that the zero-order free mode, or TEM wave, should dominate the waveguide with minimal high-order coupling along the propagation direction.Compared to existing methods that treat dense nails as three-dimensional homogenized materials, this study is more applicable to scenarios involving relatively sparse nails at higher frequencies.
Time-reversal invariance violation effect in dd scattering*
Authors: Platonova M. N. , Uzikov Yu. N.
Published: December 2024

A formalism is developed for calculating the signal of the violation of time-reversal invariance, provided that space-reflection (parity) invariance is conserved during the scattering of tensor-polarized deuterons on vector-polarized deuterons. The formalism is based on Glauber theory and fully considers the spin dependence of

elastic scattering amplitudes and the spin structure of colliding deuterons. Numerical calculations are performed in the laboratory proton energy range

–1.2 GeV using the SAID database for spin amplitudes and in the energy region of the SPD NICA experiment corresponding to the invariant mass of the interacting nucleon pairs

–25 GeV, using two phenomenological models of

elastic scattering. It is found that only one type of the time-reversal non-invariant parity conserving

interaction gives a non-zero contribution to the signal in question, which is important for isolating an unknown constant of this interaction from the corresponding data.
Constraining Schwarzschild Models with Orbit Classifications
Authors: Long Richard J.
Published: December 2024

A simple orbit classification constraint extension to stellar dynamical modeling using Schwarzschild’s method is demonstrated. The classification scheme used is the existing ‘orbit circularity’ scheme (λ_z) where orbits are split into four groups - hot, warm, cold and counter rotating orbits. Other schemes which can be related to the orbit weights are expected to be viable as well. The results show that the classification constraint works well in modeling. However, given that orbits in external galaxies are not observable, it is not clear how the orbit classification for any particular galaxy may be determined. Perhaps range constraints for different types of galaxies determined from cosmological simulations may offer a way forward.
Study on Soil Vibration Propagation Characteristics Caused by Subway near Foundation Pit
Authors: Xia Zhifan , Huang Peng , Huang Yanwu , Zhang Jingjing
Published: December 2024

Based on the Shanghai Metro Line 12, a three-dimensional finite element calculation model is established to study the influence of adjacent foundation pits on subway train vibration propagation. A comparative analysis is conducted on the vibration response and propagation characteristics of the subway during single and bidirectional metro operation under free field and adjacent foundation pit conditions. The effects of subway train speed and tunnel depth on vibration propagation are discussed in detail. It is indicated that as the train speed increases, the ground vibration increases, and the increasing trend of vertical acceleration gradually slows down. The deeper the tunnel is buried, the smaller the ground vibration response. The variation of tunnel burial depth has no effect on the attenuation law of vertical vibration.
Darboux integrability of hyperbolic partial differential equations: is it a property of integrals rather than equations?
Authors: Startsev S Ya
Published: December 2024

We consider functions that depend on x, y,

u
(
x
,
y
)

and its derivatives with respect to x. Among them, we are interested in functions g for which there exists an ordinary differential operator such that its composition with the Fréchet derivative of g is expressed in terms of x, g and the total derivatives of g with respect to x. Integrals of the smallest orders for Darboux integrable partial differential equations (PDEs) possess the above property (which is completely independent of any PDE). We prove an almost converse statement: if a function g has the above property and there exists an equation for which g is an integral, then this equation admits integrals in the other characteristic and is therefore Darboux integrable. In particular, if g is an integral of the smallest order for a Darboux integrable equation, then any equation admitting the same integral g is Darboux integrable too. These facts can be used to check the already known lists of Darboux integrable equations for completeness and to find new Darboux integrable equations. As an illustration of this approach, we obtain a family of the Darboux integrable equations, which is probably new. We also briefly discuss whether the Darboux integrability can be defined via properties of the integrals only (without employing the PDEs). If this is possible, then the classification of the Darboux integrable equations may be reduced to the classification of the functions with these properties.
Results of the study of operating conditions in the cylinder and changes in the characteristics of diesel and gas diesel motor oils
Authors: Utaev Sobir , Temurkhanov Anver
Published: December 2024

This article discusses the results of a study of changes in the characteristics of M10G2 oils during the operation of diesel engines and gas engines based on diesel engines. During engine operation, the oil in the lubrication system circulates under conditions of temperature difference. The thermal load of the engine depends on the engine boost. Thermal stress and temperature of hot gases intensively influence the oxidation of oil; this process occurs in the annular zone of the pistons. The operating conditions are harsh in the working surface of the cylinder in the piston stroke area, in this area the oil is subject to thermal decomposition and high oxidation intensity. When operating a diesel engine, compared to a gas-diesel engine, the main oil indicators such as viscosity, density, mechanical impurities, high- and low-temperature characteristics, chemical characteristics such as base number have lower limit values, and the oil service life can be considered 1.5 times higher when operating at gaseous fuel. The alkaline number in samples of used oils varies from 2.24 to 1.4, which indicates the emergency condition of the used oil. The results of analyzes of the alkaline number of the studied motor oils show that when the engine is running on gaseous fuel it decreased on average from 6.0 to 2.2 mg KOH/g, and when running on diesel fuel from 6.0 to 1.4 mg KOH/g. i.e. below the permissible level.
Method to improve the classification accuracy by in situ laser cleaning of painted metal scraps during laser-induced breakdown spectroscopy based sorting
Authors: LEE Jaepil , SHIN Sungho , JANG Inseok , BAE Seongguk , JEONG Sungho
Published: December 2024

Scrap metals are typically covered with surface contaminants, such as paint, dust, and rust, which can significantly affect the emission spectrum during laser-induced breakdown spectroscopy (LIBS) based sorting. In this study, the effects of paint layers on metal surfaces during LIBS classification were investigated. LIBS spectra were collected from metal surfaces painted with black and white paints by ablation with a nanosecond pulsed laser (wavelength = 1064 nm, pulse width = 7 ns). For the black-painted samples, the LIBS spectra showed a broad background emission, emission lines unrelated to the target metals, large shot-to-shot variation, and a relatively low signal intensity of the target metal, causing poor classification accuracy even at high shot numbers. Cleaning the black paint layer by ablating over a wide area prior to LIBS analysis resulted in high classification accuracy with fewer shot numbers. A method to determine the number of cleaning shots necessary to obtain high classification accuracy and high throughput is proposed on the basis of the change in LIBS signal intensity during cleaning shots. For the white-painted samples, the paint peeled off the metal surface after the first shot, and strong LIBS signals were measured after the following shot, which were attributed to the nanoparticles generated by the ablation of the paint, allowing an accurate classification after only two shots. The results demonstrate that different approaches must be employed depending on the paint color to achieve high classification accuracy with fewer shot numbers.
Equivariant Variational Quantum Eigensolver to detect phase transitions through energy level crossings
Authors: Crognaletti Giulio , Di Bartolomeo Giovanni , Vischi Michele , Loris Viteritti Luciano
Published: December 2024

Level spectroscopy stands as a powerful method for identifying the transition point that delineates distinct quantum phases. Since each quantum phase exhibits a characteristic sequence of excited states, the crossing of energy levels between low-lying excited states offers a reliable mean to estimate the phase transition point. While approaches like the Variational Quantum Eigensolver are useful for approximating ground states of interacting systems using quantum computing, capturing low-energy excitations remains challenging. In our study, we introduce an equivariant quantum circuit that preserves the total spin and the translational symmetry to accurately describe singlet and triplet excited states in the J
1–J
2 Heisenberg model on a chain, which are crucial for characterizing its transition point. Additionally, we assess the impact of noise on the variational state, showing that conventional mitigation techniques like Zero Noise Extrapolation reliably restore its physical properties.
Framing flooding in African cities: a corpus-assisted discourse analysis of the phenomenon in the Ghanaian press
Authors: Terkper Paulina , Baddianaah Issah
Published: December 2024

Increasing climate change and urban planning deficiencies have exacerbated flood disasters in African cities, attracting widespread media discussion and public concern. This study examines the discursive construction of perennial flooding in Accra, in the Ghanaian press, to bring to light how the phenomenon is represented with regards to whether or not it contributes to a proper appreciation of the situation in attempting to address the problem. It uses as dataset an 86,602-word specialised corpus built from news reports on flooding and a 422,436-word reference corpus (written component of International Corpus of English, Ghana). The study employs a Corpus-Assisted Discourse Studies (CADS) approach to explore the discourse using Keyword analysis, Concordance lines and Collocate analysis. Findings revealed framing of perennial flooding in the city as an unwelcome threat, as it is found to colligate with: ‘problems, damage, death and loss’, giving it a negative discourse prosody. In addition, there is unclear (de)construction of the major cause of the floods in the news, as experts assert that siltation of the drains is the major challenge, but what is often projected by the media as the cause is choked gutters. The findings inform policymakers that robust proactive measures, public education and sensitisation, as well as a firm commitment on the part of the government, in particular, are needed to tackle the perennial floods in Accra.
Dynamic hybrid visual-thermal multimodal perception neuromorphic devices based on defect modulation of electrospun nanofibers
Authors: Wen Shengkai , Liu Yanan , Li Yi , Xie Liang , Li Jun , Zhang Jianhua
Published: December 2024

Neuromorphic devices, inspired by the intricate architecture of the human brain, have garnered recognition for their prodigious computational speed and sophisticated parallel computing capabilities. Vision, the primary mode of external information acquisition in living organisms, has garnered substantial scholarly interest. Notwithstanding numerous studies simulating the retina through optical synapses, their applications remain circumscribed to single-mode perception. Moreover, the pivotal role of temperature, a fundamental regulator of biological activities, has regrettably been relegated to the periphery. To address these limitations, we proffer a neuromorphic device endowed with multimodal perception, grounded in the principles of light-modulated semiconductors. This device seamlessly accomplishes dynamic hybrid visual and thermal multimodal perception, featuring temperature-dependent paired pulse facilitation properties and adaptive storage. Crucially, our meticulous examination of transfer curves, capacitance–voltage (C–V) tests, and noise measurements provides insights into interface and bulk defects, elucidating the physical mechanisms underlying adaptive storage and other functionalities. Additionally, the device demonstrates a variety of synaptic functionalities, including filtering properties, Ebbinghaus curves, and memory applications in image recognition. Surprisingly, the digital recognition rate achieves a remarkable value of 98.8%. These discernments furnish crucial insights for the prospective evolution of intricate neuromorphic systems.
Real-time rainfall projection in hilly areas using ARLSTM model: a case of Dharamshala, India
Authors: Mahajan Deepika , Sharma Sandeep , Saini Komal
Published: December 2024

Rainfall forecasting is essential in many industries, including agriculture, hydrology, urban planning, disaster management, and renewable energy. However, typical forecasting approaches frequently fail to reflect the complex spatiotemporal dynamics inherent in rainfall patterns, particularly in hilly areas. Since, the mountainous terrain influences wind patterns, moisture flow, and temperature inversions which affect precipitation patterns, adding challenge to meteorologists. So, designing a predictive forecasting model is essential for people and governments to make preventive measures in time. In recent years, the introduction of Internet of Things (IoT) technology and advances in machine learning (ML) techniques have provided a promising route for improving rainfall prediction accuracy. Real-time data on environmental elements such as temperature, wind speed, air pressure, and humidity can be collected using IoT sensor networks. This research paper investigates the efficacy of the Auto-Regressive Integrated Moving Average - Long Short-Term Memory (ARIMA-LSTM) model for real-time rainfall prediction in hilly towns like Dharamshala. Utilizing real-time data collected from sensors and using edge to preprocess it before sending it to the cloud, this study explores the integration of traditional time series analysis techniques with deep learning architectures to enhance predictive accuracy. The propounded model is paralleled against alternative forecasting approaches and shows a significant reduction in Root Mean Square Error (RMSE), Relative Root Mean Square Error (RRMSE), and Mean Square Error (MSE). Furthermore, it had a 0% Absolute Percentage Bias (APB), a high Nash-Sutcliffe Efficiency (NSE) of 0.99, and a low Theil’s coefficient (U2) of 0.01. These results demonstrate that the ARLSTM model outperforms other forecasting models of rainfall prediction.
Process tomography of structured optical gates with convolutional neural networks
Authors: Jaouni Tareq , Di Colandrea Francesco , Amato Lorenzo , Cardano Filippo , Karimi Ebrahim
Published: December 2024

Efficient and accurate characterization of an experimental setup is a critical requirement in any physical setting. In the quantum realm, the characterization of an unknown operator is experimentally accomplished via Quantum Process Tomography (QPT). This technique combines the outcomes of different projective measurements to reconstruct the underlying process matrix, typically extracted from maximum-likelihood estimation. Here, we exploit the logical correspondence between optical polarization and two-level quantum systems to retrieve the complex action of structured metasurfaces within a QPT-inspired context. In particular, we investigate a deep-learning approach that allows for fast and accurate reconstructions of space-dependent SU(2) operators by only processing a minimal set of measurements. We train a convolutional neural network based on a scalable U-Net architecture to process entire experimental images in parallel. Synthetic processes are reconstructed with average fidelity above 90%. The performance of our routine is experimentally validated in the case of space-dependent polarization transformations acting on a classical laser beam. Our approach further expands the toolbox of data-driven approaches to QPT and shows promise in the real-time characterization of complex optical gates.
Changes in upper airway airflow after rapid maxillary expansion considering normal craniofacial development as a factor: a retrospective study using computer fluid dynamics
Authors: Lo Giudice Antonino , Polizzi Alessandro , Lagravere Manuel , Flores-Mir Carlos , Isola Gaetano , Ronsivalle Vincenzo , Leonardi Rosalia
Published: December 2024

Background/Objectives

Evidence suggests nasal airflow resistance reduces after rapid maxillary expansion (RME). However, the medium-term effects of RME on upper airway (UA) airflow characteristics when normal craniofacial development is considered are still unclear. This retrospective cohort study used computer fluid dynamics (CFD) to evaluate the medium-term changes in the UA airflow (pressure and velocity) after RME in two distinct age-based cohorts.

Materials/Methods

The study included 48 subjects who underwent RME divided into two cohorts: a 6−9-year-old group (EEG group: early expansion group − 25 subjects) and an 11−14-year-old group (LEG group: late expansion group − 23 subjects). The nasal cavity and pharyngeal anatomy were segmented from Cone-beam computed tomography reconstructions taken before RME (T0) and 12 after RME (T1). The two UA airflow variables (pressure and velocity) were simulated using CFD. The maxillary expansion (PW) amount, two cross-sectional area measurements (CS1 = anterior cross-section and CS2 = posterior cross-section), and four UAs’ subregions (NC = nasal cavity, PAtotal = pharyngeal airway, NP = nasopharynx, VP = velopharynx, and OP = Oropharynx) were also considered. All data were statistically analyzed.

Results

At the baseline, the airflow pressure, velocity, and noted obstructions were significantly higher in the EEG compared to LEG. At T1, there was a significant improvement in the median airway parameters in both groups, which was remarkably greater in the EEG. A significant negative correlation was found between pressure/velocity and both CS2 and NP. According to the CFD plots, the airflow pressure and velocity changes could be attributed to the reduction of the adenotonsillar tissues’ sizes, which were remarkably more marked in the EEG.

Limitations

The results of this study cannot be generalized since they referred to a retrospective orthodontic sample without obstructive adenotonsillar hypertrophy.

Conclusions/Implications

Twelve months after RME, normal craniofacial developmental changes and spontaneous adenotonsillar tissues volume regression could represent the most significant factors influencing UA airflow changes.