bluuebunny/crossref_metadata_2025 huggingface dataset:
A new ground electronic state potential energy surface of HeLiH+: Analytical representation and investigation of the dynamics of He + LiH+ (v = 0, j = 0) → LiHe+ + H reaction
Authors: Rawat Ajay Mohan Singh , Alamgir Mohammed , Goswami Sugata , Mahapatra Susanta
Published: September 2024

An improved global potential energy surface (PES) for the electronic ground state of the HeLiH+ system is reported. The data points are calculated at the full configuration-interaction level of theory and extrapolated to the complete basis set limit. The fitting procedure implements a combination of neural network and Aguado–Paniagua functional forms to fit the ab initio data points. The fitted surface reproduces the ab initio data points accurately in short as well as long ranges and has an overall root mean square error of 1.76 × 10−3 eV (14.21 cm−1) in energy space <10 and 9.28 × 10−4 eV (7.48 cm−1) upto 2 eV. The optimized global minimum is also accurately reproduced using the fitted surface. To establish the accuracy of the new PES, dynamics investigation of the He + LiH+(v = 0, j = 0) → LiHe+ + H reaction is performed using the Coriolis coupled quantum mechanical and quasi-classical trajectory methods. The results, such as integral cross sections and rate constants, show the effect of the opening of the collision-induced dissociation (CID) channel at low collision energy and are significantly different from the earlier study of Tacconi et al. [Phys. Chem. Chem. Phys. 14, 637–645 (2012)]. These discrepancies appear to be a result of the treatment of the CID channel in the dynamics calculations, which is excluded from the reactive channel in the current work.
Interfacial contact characteristics and energy evolution of gas-bearing coal seams at different shear rates
Authors: Hu Jiaying , Guo Yangyang , Chen Xuexi , Chen Xingyu , Yang Tao
Published: September 2024

Coal mine geological tectonic belts have a high incidence of coal mine gas disasters. The deformation and displacement of tectonic belts under geological action are the typical characteristics of a “tectonic interface.” It is of great significance to study the shear mechanics and stability of the tectonic interface of gas-bearing coal seams to clarify the mechanisms of geologic structure control outburst. In this paper, the interfacial shear seepage coupling tests of coal seams under different shear rates are carried out, and the displacement and mechanical properties of interfacial contact points under different shear rates are studied on a mesoscale basis. The main conclusions are as follows: with the increase in shear rate, the interfacial shear strength and stick-slip stress decrease, but the number of stick-slip events increases correspondingly. The interfacial friction coefficient is negatively correlated with the shear rate, and the sensitivity of the interfacial friction coefficient decreases with the increase in the shear rate. With the increase in shear rate, the meshing degree of shear convex decreases and the meso-contact stress decreases. As the shear rate increases, less energy is released and fewer cracks are generated by dissipated energy. Finally, the evolution law of macroscopic mechanics-meso-contact-energy transformation of the interface during shearing is expounded.
Review of Scientific Instruments New Products
Authors: Mandelis Andreas
Published: September 2024

To supplement manufacturers’ information, this department will welcome the submission by our readers of brief communications reporting measurements on the physical properties of materials that supersede earlier data or suggest new research applications.
Dried distiller’s grains in the diets of feedlot lambs: implications for production, carcass characteristics and rumen morphometrics
Authors: dos Santos Isabela J. , G. Dias Junior Paulo C. , S. Vicente Ana C. , G. de Assis Rhaissa , Carlis Matheus S. P. , Biava Janaina S. , Alvarenga Tharcilla I. R. C. , Comelli Jamile H. , Pires Alexandre V. , Relling Alejandro E. , Ferreira Evandro M.
Published: September 2024

Context The demand and production of renewable fuels are boosting the production of biofuels. Agricultural industries have been playing a role in the increase of ethanol production from corn and, consequently, their by-products. Dried distiller’s grain (DDG) is a by-product of corn ethanol and can be used as a source of protein and energy in the diet of feedlot lambs. Aims The objectives of this experiment were to evaluate the effects of including DDG in high-concentrate diets on performance, rumen morpho-histology, and carcass characteristics in feedlot lambs. Methods Forty-five Santa Inês × Dorper male lambs with an initial body weight of 21 ± 3.2 kg (mean ± s.d.) and 82 ± 12 days old (mean ± s.d.) were distributed in a randomised complete-block design (nine blocks and five treatments). The experimental diets contained 900 g/kg of concentrate and 100 g/kg of coastcross hay, and DDG was used in replacement of soybean meal and corn. Lambs were fed one of the following five diets for 112 days: control without DDG (0DDG), or diet with 150 (150DDG), 300 (300DDG), 450 (450DDG) and 600 (600DDG) g/kg DM of DDG. Key results The inclusion of DDG from 150 up to 600 g/kg DM in the diet of the lambs linearly decreased (P < 0.01) dry-matter intake (DMI), net energy of maintenance intake, net energy of gain, average daily gain, final body weight and feed efficiency (P < 0.01). The inclusion of DDG linearly decreased (P ≤ 0.04) hot carcass weight, cold carcass weight, hot carcass yield and cold carcass yield. For ruminal morpho-histology, there was a linear decrease in the area of papillae and absorptive surface area (P < 0.01) Conclusions An increase in the DDG level from 150 to 600 g/kg DM in the diet of lambs negatively affected feedlot performance, with detrimental effects on carcass traits and the development of rumen papillae. The lambs showed low acceptance of DDG, even at the lowest level of dietary inclusion (150g/kg DM) as DMI was impaired. Implications DDG should be used with caution in diets for finishing lambs. Dietary inclusion of DDG up to 150 g/kg DM is recommended. Higher inclusions levels may significantly affect performance and carcass weight and yield.
State and trend of surface soil organic carbon stocks and associated nutrients in Tongatapu, Kingdom of Tonga
Authors: Stockmann U. , Farrell M. , Carter T. , Krawitz S. , Wong V. N. L. , Minoneti V. , Finau D. , Sharma A. , Barringer J. , Manu V. T. , Karunaratne S. , Macdonald B. C. T.
Published: September 2024

Context The status and temporal trend in soil organic carbon (SOC) stocks are unknown in Tongatapu, the main island and agriculture hub of the Kingdom of Tonga. This is a critical shortcoming in relation to agricultural sustainability and food security. Aim Evaluate the soil organic carbon stocks within Tongatapu’s main soil series relative to historic data. Methods Historical studies were used to establish a SOC baseline for different soil series on Tongatapu. These sites were revisited and sampled in 2018 and the SOC content of the soil samples was determined using a dry combustion analytical method. Changes in the soil nitrogen (N), phosphorus (P), and sulfur (S) nutrient pools were estimated using stoichiometry. Key results There was a decline in SOC stocks over the last 20–30 years. The mineralisation of soil organic matter, as represented by the decline in SOC stocks, has likely also reduced the pool of N, P, and S. Soils with the greatest SOC stocks (>50 t C ha−1) declined at the highest rates relative to soils with SOC stocks of 20–30 t C ha−1. Conclusion Agricultural practices that are employed on Tongatapu have caused the decline of SOC stocks and are threatening sustainable agriculture production. Implications This study shows that new farming and soil management practices should be employed that build SOC and broader soil functions.
Comparison of arm cavity optical losses for the two wavelengths of the Einstein telescope gravitational wave detector
Authors: Le Jean Maxime , Degallaix Jerome , Hofman David , Pinard Laurent , Forest Danièle , Granata Massimo , Michel Christophe , Steinlechner Jessica , Amra Claude , Lequime Michel , Zerrad Myriam
Published: September 2024

A new generation of gravitational wave detectors is currently being designed with the likely use of a different laser wavelength compared to current instruments. The estimation of the optical losses for this new wavelength is particularly relevant to derive the detector sensitivity and also to anticipate the optical performances of future instruments. In this article, we measured the absorption and angle-resolved scattering of several mirror samples in order to compare optical losses at a wavelength of 1064 and 1550 nm. In addition, we have carried out simulations of the Einstein Telescope arm cavities at 1064 and 1550 nm taking into account losses due to surface low-spatial frequency flatness. Our results suggest that optical losses as measured at 1064 nm are about twice as large as those at 1550 nm as predicted with a simple model.
Paddle-wheels, friction, and moving-boundary work
Authors: Crespi Andrea
Published: September 2024

Moving-boundary work, also called pressure-volume work or expansion work, is perhaps the main form of work discussed in introductory courses about thermodynamics. Here, we take a particular definition of this kind of thermodynamic work. On this basis, we show with simple reasoning that significant phenomena involving dissipation of mechanical energy, often mentioned as well in those courses but with a vague formalization, can be traced back right to moving-boundary processes. We refer in particular to the conversion of external work into internal energy in paddle-wheel experiments such as the one conducted by J. P. Joule in 1850, and to other processes involving friction.
Absorption of electromagnetic waves by cylindrical surface plasmon resonance
Authors: Zhou Mingjie , Tan Haiyun , Zhuge Lanjian , Wu Xuemei
Published: September 2024

The absorption characteristics of cylindrical surface plasmon resonance (CSPR) have been studied. We demonstrated that a single plasma column with CSPRs can achieve high absorptivity at the plasmon frequency. We also studied the effects of plasma density and collision frequency on the absorptivity. As both of them increase, the corresponding absorptivity tends to increase first and then decrease, but with different reasons. Such manifestation is explained by analyzing transmission and reflection spectra in both cases, as well as magnetic field distribution patterns at the frequency of plasmon. On the one hand, the increase in plasma density leads to the enhancement of plasmons, improving transmittance; On the other hand, the increase in collision frequency leads to a weakening of plasmons and an increase in reflectivity. Finally, we investigated the absorption characteristics of plasmons in the plasma photonic crystals (PPCs) structure and overcame the absorption attenuation caused by the increase in plasma density by increasing the number of plasma columns. Meanwhile, the absorption generated by surface plasmon resonance is not affected by the lattice constant of PPCs. The research has shown that efficient absorption can be achieved using CSPR, resulting in extremely high absorptivity when using fewer plasma columns. Finally, we verified the absorption ability of CSPRs through experiments.
Enhancing the yellow-LED performance with improvised pre-stress alleviation layer: a theoretical and numerical analysis
Authors: Singh Chandra Prakash , Ghosh Kankat
Published: September 2024

The decline in quantum efficiency observed in yellow-LEDs emitting wavelength around ∼575 nm, commonly known as the ‘green-yellow gap’, is predominantly influenced by the fact that high In-content In

x

Ga1−x
N/GaN (x = 30%) yellow-multiple quantum wells (yellow-MQWs) are typically grown on GaN template. This configuration leads to substantial compressive stress, contributing to the structural defects and the significant quantum confined stark effect. To address this challenge, our strategy involves achieving superior lattice constant alignment within the yellow-MQWs by growing a pre-stress alleviation layer (PSAL) prior to the growth of yellow-MQWs. Our comprehensive theoretical study, coupled with numerical simulations, aimed to explore the impact of two distinct practical and commercially viable PSAL approaches: pre-quantum well, comprising short periods of InYGa1−Y
N/GaN and pre-thin layer, incorporating a thin layer of In
Z
Ga1−Z
N. Following a thorough analysis of these approaches, we propose an innovative improved optimized structure that demonstrates the highest internal quantum efficiency of 74.2%, minimal efficiency droop of 14.7% at 20 A cm−2, and a 20 nm favourable red-shift in electroluminescence characteristic with narrower full-width-half-maximum of 28 nm without any adverse effect on the pure yellow-color emission at 20 A cm−2. This advancement holds promise for providing better crystal quality and addressing the green-yellow gap issue in yellow-LED technology.
UV and blue light cut-off filters using phosphorus doped carbon quantum dots extracted from raw egg yolk
Authors: Hegazy M M , Ayad M M , Ghali M
Published: September 2024

Using raw egg yolk and phosphoric acid, a simple hydrothermal treatment for synthesizing carbon quantum dots (CQDs) has been developed for the manufacture of UV and blue light-blocking filters. Several samples with different doping ratios of phosphoric acid were prepared. Namely: reference (REF.), 25%, 50%, 75% and 100%. The synthesized CQDs were embedded in polyvinyl alcohol (PVA) to produce blocking-light films with desired optical properties. Six films were prepared, one of which was PVA alone, and the other five samples were the prepared CQDs, with different phosphorus doping levels, mixed with PVA in a 1:1 ratio. We aimed to test the ability of these films to block ultraviolet rays and blue light. The experimental results revealed that the prepared films were able to block the blue light, emitted from a 450 nm blue LED, with blocking ratios of 7%, 17.5%, 27%, 30%, 37% and 70% for the films: PVA alone, REF., 25%, 50%, 75% and 100%, respectively. Moreover, it was found that these phosphorus-doped CQDs films can prevent destructive UV light with substantial value reaching 86%. These results suggest that carbon dots, derived from raw egg yolk, can be effectively applied to block harmful UV and blue lights.
Investigation of PCVSi
− defect in 4H–SiC as a candidate for a qubit
Authors: Sun Lei , Zhang Wenxu , Peng Bin , Zhang Wanli
Published: September 2024

Exploration of spin defects in semiconductors for possible qubits encourages the development of the quantum field. Silicon carbide (SiC) is a suitable platform to carry spin defects, due to its excellent electrical, mechanical and optical properties, together with its convenience for crystallographic growth and doping processes. In this study, a negatively charged phosphorus-vacancy (PCVSi
−) defect, consisting of a silicon vacancy and nearby substitution of a phosphorus atom to a carbon atom in 4H–SiC, is investigated by first-principles calculations. This defect is demonstrated to possess a high spin (S = 1) with relatively low formation energy. Computed zero-phonon line energy and zero-field splitting parameters of this defect are close to those of neutral divacancy (VCVSi
0), negatively charged nitrogen-vacancy center (NCVSi
−) and some other color centers, which indicate a similarity of both optical and spin properties among them. Moreover, the electron spin coherence time of this defect turns out to be 1.15–1.40 ms. Such a long coherence time provides the defect with reliability for quantum information processing. Our results show that the PCVSi
− defect can be a promising candidate for a qubit.
An in-situ tool wear measurement method based on super-pixels and enhanced corner detection algorithm
Authors: Wang Zhizhuo , Wang Guofeng , Wang Haotian , Li Xuwei , Yan Shuang , Sheng Yanliang
Published: September 2024

In robotic milling scenarios, lighting conditions that are difficult to optimize and random angles of the cutting edge often lead to inaccuracies in in-situ tool wear detection. This paper proposes a method based on machine vision to accurately measure the wear parameters of end mills. Firstly, a cropping algorithm based on polar coordinate transformation is introduced to extract the Region of Interest from the flank face of the tool bottom. Subsequently, a segmentation algorithm that combines super-pixels and multi-thresholding is proposed, with a focus on maintaining the connectivity of the damage regions during segmentation. Finally, an algorithm based on improved corner detection is presented to reconstruct the tool breakage region. Experimental results demonstrate that the proposed method achieves precise tool wear measurement despite random cutting edge angles and exhibits good robustness under varying lighting conditions. In the in-situ detection experiment, the method achieved a measurement accuracy of 97% for maximum wear width and 95% for wear area, indicating the effectiveness of the proposed method.
Modeling martensitic transformation temperatures in Zirconia–Ceria solid solutions using machine learning interatomic potentials
Authors: Rettenmaier Owen T , Gabriel Joshua J , Patala Srikanth
Published: September 2024

Shape memory ceramics (SMCs), while exhibiting high strength, sizeable recoverable strain, and substantial energy damping, tend to shatter under load and have low reversibility. Recent developments in SMCs have shown significant promise in enhancing the reversibility of the shape memory phase transformation by tuning the lattice parameters and transformation temperatures through alloying. While first-principles methods, such as density functional theory (DFT), can predict the lattice parameters and enthalpy at zero Kelvin, calculating the transformation temperature from free energy at high temperatures is impractical. Empirical potentials can calculate transformation temperatures efficiently for large system sizes but lack compositional transferability. In this work, we develop a model to predict transformation temperatures and lattice parameters for the Zirconia–Ceria solid solutions. We construct a machine learning inter-atomic potential (MLIAP) using an initial dataset of DFT simulations, which is then iteratively expanded using active learning. We utilize reversible scaling to compute the free energy as a function of composition and temperature, from which the transformation temperatures are determined. These transformation temperatures match experimental trends and accurately predict the phase boundary. Finally, we compare other relevant design parameters (e.g. transformation volume change) to demonstrate the applicability of MLIAPs in designing SMCs.
Selective area epitaxy of in-plane HgTe nanostructures on CdTe(001) substrate
Authors: Chaize N , Baudry X , Jouneau P-H , Gautier E , Rouvière J-L , Deblock Y , Xu J , Berthe M , Barbot C , Grandidier B , Desplanque L , Sellier H , Ballet P
Published: September 2024

Semiconductor nanowires (NWs) are believed to play a crucial role for future applications in electronics, spintronics and quantum technologies. A potential candidate is HgTe but its sensitivity to nanofabrication processes restrain its development. A way to circumvent this obstacle is the selective area growth technique. Here, in-plane HgTe nanostructures are grown thanks to selective area molecular beam epitaxy on a semi-insulating CdTe substrate covered with a patterned SiO2 mask. The shape of these nanostructures is defined by the in-plane orientation of the mask aperture along the <110>, <1

1
¯

0>, or <100> direction, the deposited thickness, and the growth temperature (GT). Several micron long in-plane NWs can be achieved as well as more complex nanostructures such as networks, diamond structures or rings. A good selectivity is achieved with very little parasitic growth on the mask even for a GT as low as 140 °C and growth rate up to 0.5 monolayer per second. For <110> oriented NWs, the center of the nanostructure exhibits a trapezoidal shape with {111}B facets and two grains on the sides, while <1

1
¯

0> oriented NWs show {111}A facets with adatoms accumulation on the sides of the top surface. Transmission electron microscopy observations reveal a continuous epitaxial relation between the CdTe substrate and the HgTe NW. Measurements of the resistance with four-point scanning tunneling microscopy indicates a good electrical homogeneity along the main NW axis and a thermally activated transport. This growth method paves the way toward the fabrication of complex HgTe-based nanostructures for electronic transport measurements.
Non-homogeneous initial boundary value problems and small data scattering of the Hirota equations posed on the half line
Authors: Li Shenghao , Mu Chunlai , Zhou Deqin
Published: September 2024

This paper deals with the well-posedness problems and scattering property of the Hirota equations posed on the right half line. We first prove the global well-posedness of the Hirota equations in three different solution spaces, including Lp
-Lq
and Bourgain related spaces, for the initial data in

H
s

(

R

+

)

with the index s being in

[

1
4

,
+
∞
)
∖
{

Z

+

1
2

}

,

[
0
,

1
4

)

and

(

−
1

4

,
0
)

, separately. The global solution is proved in different solution spaces with different techniques based on different ranges of s. Then we prove that the Hirota equation posed on the half line admits the scattering property in

L
2

(

R

+

)

if the initial data exponentially decays at infinity. As far as we know, this is the first scattering result for dispersive type equations posed on the half-line although there are numerous and wonderful scattering results for dispersive equations posed on the whole domain. The key and new ingredient in this paper is to construct rotation-rescaling transformations on the Hirota equations which lead to complex-valued gKdV equations and KdV-Burgers equations. We apply the inhomogeneous and homogeneous boundary operator estimates as well as the regularity of the solution space for complex-valued gKdV equations and KdV-Burgers equations to obtain well-posedness and scattering property.
Trace formulas revisited and a new representation of KdV solutions with short-range initial data
Authors: Rybkin Alexei
Published: September 2024

We put forward a new approach to Deift-Trubowitz type trace formulas for the 1D Schrodinger operator with potentials that are summable with the first moment (short-range potentials). We prove that these formulas are preserved under the KdV flow whereas the class of short-range potentials is not. Finally, we show that our formulas are well-suited to study the dispersive smoothing effect.
Influence of electron cyclotron current drive on the pressure crashes caused by the 2/1 double tearing modes
Authors: Li J Y , Zhang W , Liu Z X , Ma Z W , Long F F , Liu Y J , Deng C C , Li P C , Yang K N , Yin X Y , Hu R Z , Zhao Y A , Li H , Xie J L , Lan T , Mao W Z , Liu A D , Zhou C , Ding W X , Zhuang G , Liu W D
Published: September 2024

A module with self-consistent evolution of driven current is developed and coupled with the resistive-MHD equations in the three-dimensional, toroidal, and nonlinear simulation code (CLT). The driven current equation is solved with a second-order accuracy symmetric scheme, which exhibits good conservation properties. With the new module, we find that the driven current can self-consistently concentrate inside the magnetic island when the parallel diffusion of the driven current is sufficiently large. The efficiency of the driven current on tearing mode suppression will then be much higher than those with stationary distributions. With the new module, the influence of electron cyclotron current drive (ECCD) on the nonlinear evolution of the 2/1 double tearing modes (DTMs) is investigated. When co-ECCD deposits on the outer resonant surface, the local magnetic shear is reduced, and the growth rates of the DTMs decrease; if ctr-ECCD deposits on the outer resonant surface, the local magnetic shear increases, and the DTMs become more unstable. However, things will be different if ECCD deposits on the inner resonant surface since the local magnetic shear is negative. The co-ECCD deposited on the inner resonant surface increases the negative shear and then promotes the growth of the DTMs; while the ctr-ECCD suppresses the DTMs. It is also found that the off-axis and central pressure crashes associated with the 2/1 DTMs can be converted to each other by properly depositing the driven current. To convert a central crash to an off-axis crash, the co-ECCD should be deposited on the outer resonant surface, or the ctr-ECCD deposited on the inner resonant surface. While, the co-ECCD should be deposited on the inner rational surface, or the ctr-ECCD deposited on the outer rational surface to convert an off-axis crash to a central crash. The co- or ctr-ECCD should be larger than a threshold for such transitions, and the threshold value is mainly determined by the location of the inner resonant surface.
Study of the evolution of density and particle transport during density relaxation phase after pellet fueling on the EAST tokamak
Authors: Nan K B , Hou J L , Zhang J , Chu Y Q , Hao B L , Li P , He Y F , Yuan J S , Geng J S , Wu X H , Si Z Y , Wang S X , Zhou Z , Qiu H T , Cao B , Zhao H L , Zuo G Z , Hu J S ,   EAST Team
Published: September 2024

The impact of pellet injection depth on particle transport characteristics and density profile evolution during the post-pellet density relaxation phase is investigated on the experimental advanced superconducting tokamak. Experiments were conducted under similar background plasma conditions and the results showed that variations in pellet deposition depths led to differences in density profiles despite comparable core fueling efficiencies. By computing the effective particle transport coefficients immediately after the pellet injection, it is found that the differences in density profiles are mainly due to significantly different transport velocities in the inner region of ρ < 0.4. The potential influence of pellets on electrostatic turbulence in this region is investigated using the trapped gyro Landau fluid model and

CO
2

laser collective scattering diagnostics. The simulation suggests that the increase in transport coefficients following pellet injection is attributed to the destabilization of lower-k modes rather than the higher-k modes within the diagnostic measurement range.
Investigating the trade-off between BV stability and ESD robustness in the n-channel LDMOS devices
Authors: Liang Hailian , Li Liping , Liu Junliang , Lin Feng , Xu Chaoqi , Sun Jun , Gu Xiaofeng
Published: September 2024

The trade-off between breakdown voltage (BV) stability and electrostatic discharge (ESD) robustness in n-channel laterally diffused metal–oxide–semiconductor (nLDMOS) devices was investigated, by utilizing computer-aided design Technology Computer Aided Design (TCAD) simulations and charge-pumping measurements. The BV stability and ESD robustness were improved by enlarging the key parameter Lj of the drift region, and introducing the step-graded doping drift region, respectively. The proposed novel nLDMOS device demonstrates superior performance, exhibiting an excellent ESD robustness of 2.0 A and a minimal 2% BV degradation after 50 000 s of hot carrier injection stress, representing a significant advancement in balancing ESD protection and long-term reliability.
Modeling and characterization of low frequency noise in self-aligned top-gate coplanar IGZO thin-film transistors
Authors: Lee Su-Hyeon , Oh Chae-Eun , Lee Dong-Ho , Hwang Jin-Ha , Han Ye-Lim , Ko Younghyun , Jeong ChanYong , Ryu WonSang , Noh Jiyong , Park Kwon-Shik , Song Sang-Hun , Kwon Hyuck-In
Published: September 2024

A modified low-frequency noise (LFN) model was proposed to accurately estimate the quality of the gate dielectric in self-aligned top-gate (SA TG) coplanar structure indium–gallium–zinc oxide (IGZO) thin-film transistors (TFTs). The proposed LFN model was derived by modifying the conventional carrier number with correlated mobility fluctuation model considering the peculiar characteristics of SA TG coplanar IGZO TFTs such as the channel length reduction due to the diffusion of hydrogen atoms or oxygen vacancies from the source/drain to the channel, as well as the relatively large source/drain parasitic resistance. The proposed model was validated by demonstrating that the measured LFN values were in good agreement with the predicted values from the proposed model for all SA TG coplanar IGZO TFTs with SiO2 gate dielectrics deposited under different plasma-enhanced chemical vapor deposition (PECVD) power densities. The near-interface gate dielectric trap densities extracted from each TFT using the proposed LFN model revealed a clear increase as the PECVD power increased, which is considered a major cause of poor positive-bias-temperature-stress stability of the SA TG coplanar IGZO TFT with SiO2 gate dielectric deposited under high PECVD power conditions.
Investigation of a new group of low band-gap semiconducting double perovskite K2MgSnZ6 (Z = Cl, Br, & I) materials and their structural, electronic, mechanical, and optical behaviors via DFT study
Authors: Iqbal Javed , Ullah Habib , Ullah Naimat , Ullah Riaz , Iqbal Zafar , Ullah Saeed , Shahat Abdelaaty A
Published: September 2024

This study focuses on potassium based double perovskite materials, specifically a series of K2MgSnZ6 (Z = Cl, Br, & I) halide materials. For the investigated materials, all primary calculations were performed using the Full-Potential Linearized Augmented Plane-Wave (FP-LAPW) method, supported by density functional theory (DFT), and implemented in the WIEN2k code. The Gold-Schmidt tolerance factor values confirm the structural stability of the compounds, while the negative values of formation energy indicate the feasibility of experimental synthesis of the studied materials. The lattice constants were observed to increase as the halide element at the ‘Z’ position was replaced by one with a larger ionic radius. The recorded band-gap values were 2.60 eV, 2.00 eV, and 1.37 eV for K2MgSnCl6, K2MgSnBr6, and K2MgSnI6, respectively. After calculating the elastic constants for all K2MgSnZ6 (Z = Cl, Br, & I) materials, it was found that they satisfy the primary conditions for Born stability required for cubic-phase materials: (1) C11 > B > C12, (2) C11 + 2C12 > 0, (3) C11 > 0, (4) C44 > 0, and (5) C11–C12 > 0. The optical parameters of the K2MgSnZ6 (Z = Cl, Br, & I) double perovskite materials suggest that these materials could play a significant role in practical applications such as solar cells, UV detectors, and various optoelectronic devices.
Localization features near the interface with nonlinear properties separating the Kerr-type nonlinear medium and a linear graded-index medium
Authors: Savotchenko S E
Published: September 2024

Interface with nonlinear response between nonlinear medium and a linear graded-index medium is considered. Exact solutions to the nonlinear Schrödinger equation with the nonlinear delta-function potential and the linear spatial term are found. The solutions describe the localized states in the self-focusing and defocusing nonlinear media separated from linear graded-index medium by interface with nonlinear response. Localization features in dependence on signs of defect parameters are analyzed. It is shown that nonlinearity of the defect leads to the possibility of localization with the different signs of defect parameters. Localized states arise for all combinations of repulsing and attracting defect, and self-focusing and defocusing nonlinear response of the defect. Localized states characterized by an asymmetric distribution with two maxima appear due to the presence of a nonlinear response of the defect. Controlling the defect parameters allows adjusting the height of the field intensity at the interface between the media and the depth of localization.
Gravitational-wave background in bouncing models from semi-classical, quantum and string gravity
Authors: Ben-Dayan Ido , Calcagni Gianluca , Gasperini Maurizio , Mazumdar Anupam , Pavone Eliseo , Thattarampilly Udaykrishna , Verma Amresh
Published: September 2024

We study the primordial spectra and the gravitational-wave background (GWB) of three models of semi-classical, quantum or string gravity where the big bang is replaced by a bounce and the primordial tensor spectrum is blue: ekpyrotic universe with fast-rolling Galileons, string-gas cosmology with Atick-Witten conjecture and pre-big-bang cosmology. We find that the ekpyrotic scenario with Galileons does not produce a GWB amplitude detectable by present or third-generation interferometers, while the Atick-Witten-based string-gas model is ruled out in its present form for violating the big-bang-nucleosynthesis bound, contrary to the original string-gas scenario. In contrast, the GWB of the pre-big-bang scenario falls within the sensitivity window of both LISA and Einstein Telescope, where it takes the form of a single or a broken power law depending on the choice of parameters. The latter will be tightly constrained by both detectors.
Gravitationally produced dark matter and primordial black holes
Authors: Bertuzzo Enrico , Perez-Gonzalez Yuber F. , Salla Gabriel M. , Funchal Renata Zukanovich
Published: September 2024

We examine how the existence of a population of primordial black holes (PBHs) influences cosmological gravitational particle production (CGPP) for spin-0 and spin-1 particles.
In addition to the known effects of particle production and entropy dilution resulting from PBH evaporation, we find that the generation of dark matter (DM) through CGPP is profoundly influenced by a possible era of PBH matter domination.
This early matter dominated era results in an enhancement of the particle spectrum
from CGPP. Specifically, it amplifies the peak comoving momentum k
⋆ for spin-1 DM, while enhancing the plateau of the spectrum for minimally coupled spin-0 particles for low comoving momenta.
At the same time, the large entropy dilution may partially or completely compensate for the increase of the spectrum and strongly mitigates the DM abundance produced by CGPP. Our results show that, in the computation of the final abundance, CGPP and PBH evaporation cannot be disentangled, but the parameters of both sectors must be considered together to obtain the final result.
Furthermore, we explore the potential formation of PBHs from density fluctuations arising from CGPP and the associated challenges in such a scenario.
A possible late-time transition of M

B
inferred via neural networks
Authors: Mukherjee Purba , Dialektopoulos Konstantinos F. , Said Jackson Levi , Mifsud Jurgen
Published: September 2024

The strengthening of tensions in the cosmological parameters has led to reconsidering the fundamental aspects of standard cosmology. The tension in the Hubble constant can also be viewed as a tension between local and early Universe constraints on the absolute magnitude M

B
of Type Ia supernova. In this work, we reconsider the possibility of a variation of this parameter in a model-independent way. We employ neural networks to agnostically constrain the value of the absolute magnitude as well as assess the impact and statistical significance of a variation in M

B
with redshift from the Pantheon+ compilation, together with a thorough analysis of the neural network architecture. We find an indication for a possible transition redshift at the z ≈ 1 region.
A new diagnostic for the null test of dynamical dark energy in light of DESI 2024 and other BAO data
Authors: Dinda Bikash R.
Published: September 2024

We introduce a new diagnostic for the null tests of dynamical dark energy alongside two other combined equivalent diagnostics. These diagnostics are useful, especially when we include anisotropic baryon acoustic oscillation (BAO) data in an analysis, to quantify the deviations from the standard ΛCDM model. We also consider another diagnostic for isotropic BAO observations. These null tests are independent of any late-time dark energy model or parametrization. With these diagnostics, we study the evidence for dynamical dark energy in light of Dark Energy Spectroscopic Instrument (DESI) 2024 data combined with cosmic microwave background (CMB) observations of the Planck 2018 mission and localH0measurements. We find no strong evidence for dynamical dark energy. The exclusion of the individual deviations at the effective redshift 0.51 of the DESI 2024 data makes the evidence even weaker. We get nearly similar results for other non-DESI BAO data. Both for DESI 2024 and other non-DESI BAO data, the evidence is almost independent of early-time physics. The evidence corresponding to the SHOES value ofH0is higher than the corresponding tRGB value ofH0for all combinations of data, but still not strong enough to reject the flat ΛCDM model.
Helicity-changing decays of cosmological relic neutrinos
Authors: Huang Jihong , Zhou Shun
Published: September 2024

In this paper, we examine the possibility that massive neutrinos are unstable due to their invisible decaysνi→νj+ϕ, whereνiandνj(fori,j= 1, 2, 3) are any two of neutrino mass eigenstates with massesmi>miandϕis a massless Nambu-Goldstone boson, and explore the implications for the detection of cosmological relic neutrinos in the present Universe. First, we carry out a complete calculation of neutrino decay rates in the general case where the individual helicities of parent and daughter neutrinos are specified. Then, the invisible decays of cosmological relic neutrinos are studied and their impact on the capture rates on the beta-decaying nuclei (e.g.,νe+3H →3He +e-) is analyzed. The invisible decays of massive neutrinos could substantially change the capture rates in the PTOLEMY-like experiments when compared to the case of stable neutrinos. In particular, we find that the helicity-changing decays of Dirac neutrinos play an important role whereas those of Majorana neutrinos have no practical effects. However, if a substantial fraction of heavier neutrinos decay into the lightest one, the detection of relic neutrinos will require a much higher energy resolution and thus be even more challenging.
MHD stability analysis against pressure and current-driven modes in the SMall Aspect Ratio Tokamak
Authors: Dominguez-Palacios J. , Garcia-Munoz M. , Toscano-Jimenez M. , Liu Y.Q. , Mancini A. , Cruz-Zabala D.J. , Berkery J.W. , Labbate J.A. , Parisi J. , Todo Y. , Reyner-Viñolas A. , Podestà M. , Viezzer E. , Oyola P. , Futatani S.
Published: September 2024

Linear magnetohydrodynamic (MHD) simulations for the SMall Aspect Ratio Tokamak (SMART) have been carried out for the first time, for both positive (PT) and negative triangularity (NT) shaped plasmas using the MARS-F code. The MHD stability of projected SMART plasmas against internal kinks, infernal modes and edge peeling-ballooning modes have been analyzed for a wide range of realistic equilibria. A stabilization of internal kinks and infernal modes is observed when increasing the safety factor profile and reducing plasma beta. PT shaped plasmas are more stable against both internal kinks and infernal modes than their counterpart NT shaped plasmas. Toroidal flows have little impact on the MHD stability of the internal kinks, but they have a strong stabilizing effect on infernal modes, which can be further mitigated in NT shaped plasmas. The MHD stability of peeling-ballooning modes is reduced in NT shaped plasmas, as observed in conventional tokamaks.
An Experimental and Numerical Investigation on Fatigue Life Cycle of Leaf Spring
Authors: Guragain Narayan , Bista Rodan , Nepal Piyush , Timilsina Birat , Sujakhu Surendra
Published: September 2024

Leaf spring is the key component of the vehicle suspension system that affects the mechanical behavior of vehicle vibration, stability, damping, and other aspects like comfort. However, depending upon the geography and road conditions, its fatigue life may vary. In Nepal, public vehicles operate mainly on paved roads and gravel roads under variable loading conditions. The road tested in this paper includes an urban road ranging 45km from Ratnapark to Sundarijal. The road consists of paved surfaces and gravel roads with varying degrees of slopes, potholes, and cracks. This paper discusses the fatigue life of a leaf spring in a public bus (TATA-709) operating on an urban road. Miner’s rule is used for the experimental analysis. Miner’s rule requires real-life data for the number of stress cycles. The data is obtained from the public bus using the data collection module. The number of repeated stress cycles was computed using the Rainflow cycle counting method and, the fatigue life is calculated implementing Miner’s rule. To validate the experimental results, fatigue simulation is carried out in ANSYS. The stress history data obtained from the experiment is fed into the fatigue model in ANSYS. The result shows that the number of cycles to failure obtained from ANSYS exceeds the number of cycles of failure obtained from Miner’s rule by 5%. This discrepancy indicates the need to consider further factors beyond this study, such as rusting, creep, and pre-stress, which considerably change the material properties and fatigue. This study sets a method to determine the fatigue life cycle of a leaf spring in various road and loading conditions both experimentally and numerically, to avoid potential damage due to failure of the suspension system in a public vehicle.
Performance analysis of meta-heuristic optimization techniques for multi-objective VLSI circuit partitioning
Authors: Roy Sharadindu , Banerjee Siddhartha
Published: September 2024

The efficiency of various stages of physical design in the Very Large Scale Integration (VLSI) circuit can be enhanced by using multi-objective optimization techniques. The circuit is partitioned into a set of modules at the beginning of the physical design phase. This step is known as circuit partitioning. All subsequent physical design stages, like floor planning, placement, pin configuration, and routing etc, are influenced by the outcome of the circuit partitioning method being used. The efficiency of the partitioning method controls the quality of ultimate architecture. The efficiency achieved by the final product may be decreased by incorrect partitioning. This study compares the effectiveness of four Meta-heuristic optimization methods include the Genetic Algorithm (GA), Satin Bowered Bird (SBO), Particle Swarm Optimization (PSO), Simulated Annealing (SA) — in terms of number of net cut, duration of sleeping mode, and efficiency in power consumption for addressing the VLSI circuit partitioning problem. This experiment achieves K-way partitioning of the circuit that minimizes net cuts as well as maximizes sleep duration simultaneously, by evaluating optimization function. Solutions developed using GA, SBO and PSO consistently surpass those acquired using SA with respect to quality of optimal solution. The average optimum net cut and sleep duration achieved by this experiment are 10.7 and 9.9 in GA ; 11.5 and 12.3 in SBO, 11.80 and 9.10 in PSO; and 16.8 and 6.7 in SA based method respectively. This research resulted in a considerable reduction in power consumption, with the system’s average power efficiency achieved by 21.6%, 26.84%, 19.85%, and 14.62%, respectively, in GA, SBO , PSO, and SA based optimizations. The experimental results are compared with a recent publication and proposed GA, SBO, and PSO based methods achieve 18.75%, 4.17%, and 1.04% improvement in terms of average net cut respectively. The proposed GA, SBO, PSO and SA based methods also achieve 44.90%, 51.30%, 40.05%, and 18.60% improvement in terms of average power efficiency.
Sea ice feedbacks cause more greenhouse cooling than greenhouse warming at high northern latitudes on multi-century timescales
Authors: Kay Jennifer E , Liang Yu-Chiao , Zhou Shih-Ni , Maher Nicola
Published: September 2024

In contrast to surface greenhouse warming, surface greenhouse cooling has been less explored, especially on multi-century timescales. Here, we assess the processes controlling the pacing and magnitude of the multi-century surface temperature response to instantaneously doubling and halving atmospheric carbon dioxide concentrations in a modern global coupled climate model. Over the first decades, surface greenhouse warming is larger and faster than surface greenhouse cooling both globally and at high northern latitudes (45–90° N). Yet, this initial multi-decadal response difference does not persist. After year 150, additional surface warming is negligible, but surface cooling and sea ice expansion continues. Notably, the equilibration timescale for high northern latitude surface cooling (∼437 years) is more than double the equivalent timescale for warming. The high northern latitude responses differ most at the sea ice edge. Under greenhouse cooling, the sea ice edge slowly creeps southward into the mid-latitude oceans amplified by positive lapse rate and surface albedo feedbacks. While greenhouse warming and sea ice loss at high northern latitudes occurs on multi-decadal timescales, greenhouse cooling and sea ice expansion occurs on multi-century timescales. Overall, this work shows the importance of multi-century timescales and sea ice processes for understanding high northern latitude climate responses.
The logical strength of minimal bad arrays
Authors: Freund Anton , Pakhomov Fedor , Soldà Giovanni
Published: September 2024

This paper studies logical aspects of the notion of better-quasi-order, which was introduced by C. Nash-Williams [Proc. Cambridge Philos. Soc. 61 (1965), pp. 697–720; Proc. Cambridge Philos. Soc. 64 (1968), pp. 273–290]. A central tool in the theory of better-quasi-orders is the minimal bad array lemma. We show that this lemma is exceptionally strong from the viewpoint of reverse mathematics, a framework from mathematical logic. Specifically, it is equivalent to the set existence principle of

Π
2
1

\Pi ^1_2

-comprehension, over the base theory 

A
T

R
0

\mathsf {ATR_0}

.
Our Polarization Problem
Authors: Talisse Robert B
Published: September 2024

Polarization looms large in popular diagnoses of contemporary democracy’s dysfunctions. But the concept of polarization is ambiguous. This chapter lays out two distinct forms of polarization: political polarization and belief polarization. The first is a measure of the divide between opposing groups, while the other is a cognitive and affective force that emerges within likeminded groups. The problem that polarization poses for democracy lies within the combination of these two forms of polarization. Our polarization problem lies with the dynamic between partisan divisiveness and in-group extremity and conformity. The upshot is that democratic citizens have a responsibility to manage their exposure to the polarization dynamic.
The rule of law condemned:
Authors: Huq Aziz Z.
Published: September 2024

Critics have launched categorical broadsides against the rule of law, and crises have tested its strength. From the political left, the intellectual tradition seeded by Karl Marx generated scathing condemnations of the ideological, even delusional, quality of what is labeled “bourgeois legalism.” From the political right, the rule of law is condemned as feeble and incoherent because it ignores core, existential realities of political life. Evgeny Pashukanis and Carl Schmitt, respectively, offered the sharpest versions of these critiques. Their criticisms presaged three of the most pressing crises experienced by the rule of law almost a century later—as a consequence of capitalism, crisis, and populism. This chapter outlines those challenges.