bluuebunny/crossref_metadata_2025_split huggingface dataset:
On generally covariant mathematical formulation of Feynman integral in Lorentz signature
Authors: László András 
Published: August 2022

Abstract
It is widely accepted that the Feynman integral is one of the most promising methodologies for defining a generally covariant formulation of nonperturbative interacting quantum field theories (QFTs) without a fixed prearranged causal background. Recent literature suggests that if the spacetime metric is not fixed, e.g. because it is to be quantized along with the other fields, one may not be able to avoid considering the Feynman integral in the original Lorentz signature, without Wick rotation. Several mathematical phenomena are known, however, which are at some point showstoppers to a mathematically sound definition of Feynman integral in Lorentz signature. The Feynman integral formulation, however, is known to have a differential reformulation, called to be the master Dyson–Schwinger (MDS) equation for the field correlators. In this paper it is shown that a particular presentation of the MDS equation can be cast into a mathematically rigorously defined form: the involved function spaces and operators can be strictly defined and their properties can be established. Therefore, MDS equation can serve as a substitute for the Feynman integral, in a mathematically sound formulation of constructive QFT, in arbitrary signature, without a fixed background causal structure. It is also shown that even in such a generally covariant setting, there is a canonical way to define the Wilsonian regularization of the MDS equation. The main result of the paper is a necessary and sufficient condition for the regularized MDS solution space to be nonempty, for conformally invariant Lagrangians. This theorem also provides an iterative approximation algorithm for obtaining regularized MDS solutions, and is guaranteed to be convergent whenever the solution space is nonempty. The algorithm could eventually serve as a method for putting Lorentz signature QFTs onto lattice, in the original metric signature.
Programmable intelligent liquid matter: material, science and technology
Authors: Zhou Yingxin , Zu Jiasheng , Liu Jing 
Published: August 2022

Abstract
Intelligent responses, transformation and desired delivery of liquids involve the intersection among materials, physics, and chemistry. The precise programmed operation has been found rather significant in many emerging fields, such as microfluidic devices, digital fluids, intelligent matter, responsive liquid machines, interactive display, soft robotic system and drug delivery, etc. This article is dedicated to presenting a comprehensive review of recent advances in the programmable actuation of liquid matter controlled by unique substrate structures and various physical fields. First, the fundamental theories of asymmetric surface microstructure and specifically administrated external effects such as electric, magnetic, acoustic, light, and thermal fields to drive droplets are illustrated. Then, we compare the advantages and disadvantages of these typical technological strategies. Furthermore, the practical multifunctional extension of programmable liquids based on different actuation mechanisms is presented. Finally, we summarize the design schemes of programming units for liquid matter and give perspective on possible future research directions, providing a brief reference for researchers interested in the field.
Ellipticity dependence of high-order harmonic generation in disordered semiconductors
Authors: Orlando Gianfranco , Lee Min-I , Ho Tak-San 
Published: August 2022

Abstract
We analyze the ellipticity dependence of high order harmonic generation (HHG) in disordered semiconductors. We show that a disordered crystal can radiated HHG spectra containing only odd harmonics of the laser frequency for all values of the ellipticity of the laser. Furthermore, we show that the HHG yield of our disordered models decreases monotonically with increasing laser ellipticity as observed in recent experiments. I particular, our numerical calculations, based on a coarse grained model, reproduce many of the qualitative features of the experimental HHG spectra of ZnO and GaAs.
A thermally erasable silicon oxide layer for molecular beam epitaxy
Authors: Hou Yaonan , Jia Hui , Tang Mingchu , Mosberg Aleksander Buseth , Ramasse Quentin M , Skandalos Ilias , Noori Yasir , Yang Junjie , Liu Huiyun , Seeds Alwyn , Gardes Frederic 
Published: August 2022

Abstract
We present a systematic study of the oxidation and deoxidation behaviours of several kinds of ultrathin silicon oxide layers frequently used in silicon (Si) technology, which in this work serve as surface protecting layers for molecular beam epitaxy (MBE). With various characterization techniques, we demonstrate that a chemically grown silicon oxide layer is the most promising candidate for subsequent removal in an ultra-high vacuum chamber at a temperature of 1000 ∘C, without making use of a reducing agent. As a demonstration, a tensile-strained Ge(100) layer is epitaxially grown on the deoxidised wafer with an atomically flat surface and a low threading dislocation density of 3.33 × 108 cm−2. Our findings reveal that the ultra-thin oxide layer grown using a chemical approach is able to protect Si surfaces for subsequent MBE growth of Ge. This approach is promising for the growth of III/V-on-Si (using Ge as a buffer) and all group-IV related epitaxy for integration on the Si photonics platforms.
Spatial attention-based convolutional transformer for bearing remaining useful life prediction
Authors: Chen Chong , Wang Tao , Liu Ying , Cheng Lianglun , Qin Jian 
Published: August 2022

Abstract
The remaining useful life (RUL) prediction is of significance to the health management of bearings. Recently, deep learning has been widely investigated for bearing RUL prediction due to its great success in sequence learning. However, the improvement of the prediction accuracy of existing deep learning algorithms heavily relies on feature engineering such as handcrafted feature generation and time–frequency transformation, which increase the complexity and difficulty of the actual deployment. In this paper, a novel spatial attention-based convolutional transformer (SAConvFormer) is proposed to establish an accurate bearing RUL prediction model based on raw vibration data without prior knowledge or feature engineering. In this algorithm, firstly, a convolutional neural network enhanced by a spatial attention mechanism is proposed to squeeze the feature maps and extract the local and global features from raw bearing vibration data effectively. Then, the extracted senior features are fed into a transformer network to further explore the sequential patterns relevant to the bearing RUL. An experimental study using the XJTU-SY rolling bearings dataset revealed the merits of the proposed deep learning algorithm in terms of root-mean-square-error (RMSE) and mean-absolute-error (MAE) in comparison with other state-of-the-art algorithms.
Atomic level simulations of the phase stability and stacking fault energy of FeCoCrMnSi high entropy alloy
Authors: Salloom Riyadh , Baskes Michael I , Srinivasan Srivilliputhur G 
Published: August 2022

Abstract
High entropy alloys (HEAs) have many promising properties beneficial to advanced technologies. However, their underlying deformation mechanisms are largely unclear. So, as a first step, we have developed a modified embedded atom method potential for FeCoCrMnSi alloys to study such mechanisms. We predict the phase stability, chemical short-range ordering (CSRO), and stacking fault energy (SFE) of a specific alloy system using molecular dynamics (MD) and hybrid Monte-Carlo and molecular dynamics (MC/MD) simulation techniques. Room temperature MD simulations showed that both the potential energy and free energy of the single phase ε-hcp alloy is marginally more stable than the γ-fcc phase alloy, which resulted in a large, negative SFE. However, the room temperature MC/MD simulation showed an opposite trend where the γ-fcc phase was found to be more stable than the ε-hcp phase, and this resulted in a small, positive SFE. The prediction of the lower energy γ-fcc phase and resultant SFE agreed well with the experimentally reported SFE and phase stability for the Fe40Co20Cr15Mn20Si5 HEA, illustrating the importance of CSRO. Also, the calculated basal SFE of the hcp phase was close to that of the fcc phase. Therefore, the MC/MD implementation is crucial for the proper prediction of the phase stability and structural evolution in this HEA system. Many previous studies showed the ability of hybrid MC/MD technique to obtain consistent structural and configurational information of different alloy systems. The current work illustrates the potential of accelerating HEA materials development by utilizing computational methods based on the MC/MD technique which can reduce time and cost associated with experimental methods.
Precisely controlled polydopamine-mediated antibacterial system: mathematical model of polymerization, prediction of antibacterial capacity, and promotion of wound healing
Authors: Zeng Yun , Yi Tong , Ma Jingwen , Han Ming , Xu Xinyi , Dan Chen  , Chen Xueli , Wang Risheng , Zhan Yonghua 
Published: August 2022

Abstract
In this work, the polydopamine (PDA)-mediated antibacterial system is synthesized for in vitro and in vivo antimicrobial activities. To precisely control the surface modification of nanodiamonds (NDs), a mathematical kinetics model of PDA deposition is established, and the conditions of synthesis reaction are discussed including the concentrations of dopamine, the reaction time, and the kinetic constant k
1, which is a function of several variables associated with the reaction temperature, light irradiance, pH value and concentration of dissolved O2 in the solution. A simulation reveals that the deposition of PDA is positively correlated with these factors and will be terminated if dissolved O2 levels are inadequate. Then, the precisely controlled thickness of PDA layers can regulate the formation of AgNPs, resulting in a rise in the intensity of Raman peaks and a predicted antibacterial activity against E. coli in vitro. An optimized antibacterial hydrogel incorporating NDs-PDA/Ag is prepared and characterized by the Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Finally, the antibacterial tests are performed to promote in vivo wound healing, as confirmed by pathological and immunohistochemical-stained tissue sections. This work provides a theoretical foundation for predicting the PDA-assisted surface modification of NDs, resulting in a divinable antibacterial effect and promoting in vivo wound healing.
Comparison of Doppler back-scattering and charge exchange measurements of E × B plasma rotation in the DIII-D tokamak under varying torque conditions
Authors: Pratt Q , Rhodes T , Chrystal C , Carter T 
Published: August 2022

Abstract
Measurements of the E × B toroidal angular velocity,

ω

E
×
B

=

E

r

/

R

B
θ

(

E

r

is the radial electric field, B

θ
is the poloidal magnetic field), are made using the Doppler back-scattering (DBS) and charge-exchange recombination (CER) spectroscopy diagnostics. DBS uses the Doppler shift of wavenumber-resolved density fluctuations while CER uses the Doppler shift of impurity emission lines to independently measure plasma parameters for calculating the local radial electric field. DBS and CER profiles of

ω

E
×
B

as a function of normalized toroidal flux (ρ) are compared at various levels of neutral beam applied torque on the plasma. Under standard neoclassical theory

ω

E
×
B

is a flux surface quantity, making it appropriate to compare across diagnostics. DBS and CER generally show good agreement when comparing

ω

E
×
B

profiles at different levels of neutral beam injection-applied torque. Furthermore, the DBS values have close to the same precision as CER values when averaged over a similar time-scale and effects, such as prompt-torque are considered. DBS is able to observe the rapid (

<

10 ms) modification of the

E

r

profile by the diagnostic neutral beam ‘blips’. This modification is most pronounced when the blip applies a large relative change in torque on the plasma. Overall, these results could have implications on transport analysis and suggests using DBS and CER in conjunction to constrain values of the E × B-shear (sometimes called

γ

E
×
B

).
Two-dimensional MHD equilibria of diamagnetic bubble in gas-dynamic trap
Authors: Khristo M S , Beklemishev A D 
Published: August 2022

Abstract
This article presents a magnetohydrodynamic (MHD) two-dimensional numerical model of diamagnetic bubble equilibria in an axisymmetric open trap. The theoretical model consists of the Grad–Shafranov equilibrium equation and the transport equation obtained within the resistive single-fluid MHDs with isotropic pressure. Found are the numerical solutions corresponding to the diamagnetic confinement mode. In particular, the equilibria of the diamagnetic bubble in the gas-dynamic multimirror trap are calculated. We investigate the effect of magnetic field corrugation on the equilibrium; the corrugation of the vacuum field is shown to lead to a rather moderate corrugation of the bubble boundary if the period of corrugation is sufficiently small. A valuable numerical result is the distribution of the diamagnetic field, which would be useful for optimizing the position of the wall-stabilization plates.
Investigation of RF driver equivalent impedance in the inductively coupled SPIDER ion source
Authors: Jain Palak , Recchia Mauro , Maistrello Alberto , Gaio Elena 
Published: August 2022

Abstract
SPIDER experiment includes an RF inductively coupled plasma source working at 0.3 Pa of gas pressure (H/D) where plasma is generated and heated by eight RF drivers, fed by four RF circuits. A single RF circuit is composed of two drivers connected in series, attached to a capacitive matching network, fed by 200 kW 1 MHz RF oscillator through a coaxial transmission line. The knowledge of driver impedance in different experimental conditions is a valuable window for understanding the characteristics of generated plasma. Direct measurement of driver impedance in SPIDER is not possible, it has been estimated via the development of a suitable electrical model of the RF circuit using as input, measurements at the oscillator’s output. This paper reports on the progress in the modeling of the SPIDER RF circuit and discusses a procedure to estimate the driver impedance exploiting also the recently available experimental measurements from the dual directional coupler. The impedance obtained with this approach, derived from measurements obtained in a recent SPIDER campaign, is reported for various operating conditions, such as RF power, gas pressure, plasma grid current, cesium injection rate, type of gas (hydrogen and deuterium), etc.
Rayleigh–Taylor instability under multi-mode perturbation: Discrete Boltzmann modeling with tracers
Authors: Li Hanwei , Xu Aiguo , Zhang Ge , Shan Yiming 
Published: August 2022

Abstract
The two-dimensional Rayleigh–Taylor Instability (RTI) under multi-mode perturbation in compressible flow is probed via the Discrete Boltzmann Modeling (DBM) with tracers. The distribution of tracers provides clear boundaries between light and heavy fluids in the position space. Besides, the position-velocity phase space offers a new perspective for understanding the flow behavior of RTI with intuitive geometrical correspondence. The effects of viscosity, acceleration, compressibility, and Atwood number on the mixing of material and momentum and the mean non-equilibrium strength at the interfaces are investigated separately based on both the mixedness defined by the tracers and the non-equilibrium strength defined by the DBM. The mixedness increases with viscosity during early stage but decreases with viscosity at the later stage. Acceleration, compressibility, and Atwood number show enhancement effects on mixing based on different mechanisms. After the system relaxes from the initial state, the mean non-equilibrium strength at the interfaces presents an initially increasing and then declining trend, which is jointly determined by the interface length and the macroscopic physical quantity gradient. We conclude that the four factors investigated all significantly affect early evolution behavior of an RTI system, such as the competition between interface length and macroscopic physical quantity gradient. The results contribute to the understanding of the multi-mode RTI evolutionary mechanism and the accompanied kinetic effects.
Modelling the Percentage of the Exchangeable Magnesium Based on the Adsorption Ratio in the Some Saline Soils Central Iraq
Authors: Kadium Abed Mahdi Abdul , Shaalan Al-Asadi Roaa Maki , Abdul Kadium Safa Mahdi 
Published: August 2022

Abstract
The study aims at estimating the percentage of exchangeable magnesium in the Some Saline Soils Central Iraq, where the percentage of the exchangeable magnesium is often estimated using hard and time-consuming lab tests, so simpler methods have been developed using soil salinity indicators. The study was conducted on the Some Saline Soils Central Iraq11 sites in depth (30-0 cm deep root area), which included regions of the Middle Euphrates Governorates (Babylon, Karbala, Najaf, Diwaniyah).The results showed a linear relationship between MgAR and EMgR with MgAR ranging between 0.55-0.99 Cmol.kg-1and EMgR ranged from 0.51-0.64 Cmol.kg-1 Also, there was a linear relationship between SAR and ESR. SAR ranged from 2.74-9.66 ( Cmol.kg-1)0.5 and ESR values ranged from 0.84- 5.00Cmol.kg-A linear regression equation was proposed for the percentage of EMgP in the soil based on its adsorption ratio EMgP = 1.114 * MgAR + 0.095 The results of the study Showed that EMgP values ranged between 0.72- 1.22 Cmol.kg-1 in study soil samples.
Digital Camera is a Surveying Tool for Predicting Effect of Fertilizer Level N, Mg on Wheat Growth and Yield in Gypsiferious Soil
Authors: Khalaf Ayad Abdullah , Hammada Ayad Ahmed , Farhan Mohammed Jarullah 
Published: August 2022

Abstract
Field experiment at the College of Agriculture / University of Tikrit / Salah Al-Din Governorate / Iraq was conducted during the agricultural season 2017 - 2018 to study the status and growth of wheat crop species Cham 6 under influence of fertilizers of nitrogen and magnesium in Gypsiferious soil using a digital camera. The experiment according to the complete randomized Design (RCBD) in three replicates was carried out. Addition of two levels of nitrogen (0, 120) kg N ha- 1 N0, N1 as Urea (46% N) were included. Magnesium was added at four levels (0,20,40,80) kg Mg ha-1 (Mg0, Mg1, Mg2, and Mg3) as magnesium sulfate. The experimental units were 2 × 4 × 3 = 24 experimental units. Nikon digital camera was used to acquire digital images and then digital processing was performed using the ERDAS program and calculation of RGB system color values. Some of the spectral indices (G, R%, CC, DGCI, HSI, B, and ChNRGB) were studied and their relation to growth and yield characteristics (number of Ears, Hay, Plant Height, Weight) as well as Chlorophyll content. The results showed a significant increase in all spectral indices with increasing the level of addition of both types of fertilizer. there’s a positive and negative correlation was found at the probability level (0.05) between the spectral indices and relation with of growth properties and yield.
Evaluation of Darbandikhan Reservoir Water Quality for Irrigation Purposes Using (IWQG) Software
Authors: Sarhat Abdulmutalib Raafat , Al-Obaidi Basim Shakir 
Published: August 2022

Abstract
It is very important to evaluate the statues of water bodies to develop a strategic plan of water management. Most of the water resources around the world are at risk and suffering with water shortage (quantities) and quality as a result of anthropogenic activities and climate change phenomena, which has adversely influenced the water quality. The quality of water in Darbandikhan Reservoir was evaluated for irrigation uses by physio-chemical parameters and implanting the (IWQG) index. Water quality index (IWQG) is a unique tool that has been recently developed in order to assess the Iraqi water resources. It helps to evaluate the overall water quality situation and its results are very helpful to choose appropriate management techniques. The outcomes of the present study revealed that the values of (IWQG) are ranged between (54.81) to (56.67) and most of the stations fall under (Moderate Restriction) category, which means that the quality of water in the reservoir is suitable for irrigation especially for light texture soil. This indicates that there is a requirement to implement a strategic plan with long term management in order to save Darbandikhan reservoir’s water quality as one of the most important local water resource.
Environmental Pollution Caused by Heavy Metals and Radioactivity in Two Governorates in Iraq
Authors: Almayahi Basim A. , Aljobory Adnan , Ameen Sajjad Ali 
Published: August 2022

Abstract
This study focused on knowing the levels of pollution caused by heavy metals (iron, lead) and gamma rays in the governorates of Maysan and Basra. The highest value of gamma rays was in Maysan governorate, there is a rise in these rates, according to the comparison conducted with international research, but these values do not represent a significant danger. The samples in this study are normal and free of pollution. It was found that the highest value of gamma rays in Maysan is 0.7 μSv/h at S5 and S9. The lowest value was 0.11 μSv/h in S3. As for the heavy elements, the highest value of iron was found at 0.2811 mg/l in Karama village (S2), and the lowest value was 0.2203 mg/l in S3 and the highest value for lead was 0.2632 mg/l in Kameet and the lowest value was 0.0033 In the village of Al-Huda, the highest value of gamma rays was observed at 0.8 uSv/h in S6 and S7, and the lowest value was 0.11 μSv/h in S2. The highest value for iron Fe was 0.3452 mg/l at the site S4 Al-Burjisiya Road 17, and the lowest value was 0.2232/ml for S9 Safwan Street, while pb had the highest value of 0.2817 mg/L in S7 of Zubair farms, and the lowest value was 0.0319 mm/L in S9 of Safwan Street.