bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of the effect of the high solids holdup ring in the fluidized bed on electromagnetic tomography
Authors: Wang Chao , Luan Xinyu , Liang Xiao , Ye Jiamin 
Published: February 2023

Abstract
Electromagnetic tomography (EMT) system based on tunneling magneto resistance (TMR) sensor, as a non-invasive multiphase flow measurement technique, can effectively detect the solid-phase distribution in the gas–liquid–solid three-phase fluidized bed with magnetic catalysts by reconstructing the permeability distribution image. The radial distribution of solid particles in the gas–liquid–solid three-phase fluidized bed with uneven fluidization is non-uniform, in which a high solids holdup ring exists near the wall of the riser. When the TMR-EMT system is used directly for image reconstruction, the high solids holdup ring will greatly reduce the image quality, further leading to the inability to detect phase information in the riser. To improve the reconstructed image by the TMR-EMT system, a removal method for the high solids holdup ring is proposed. The method firstly estimates the equivalent thickness of the high solids holdup ring based on the boundary measurement data. Then the influence of the high solids holdup ring on the boundary measurement data is subtracted. By the removal method, the internal phase distribution information is prominent. The simulation and experimental results demonstrate that the proposed method can realize the permeability distribution detection by the TMR-EMT system in the presence of the high solids holdup ring.
Application of nanofibrous protein for the purification of contaminated water as a next generational sorption technology: a review
Authors: Anani Osikemekha Anthony , Adama Kenneth Kennedy , Ukhurebor Kingsley Eghonghon , Habib Aishatu Idris , Abanihi Vincent Kenechi , Pal Kaushik 
Published: February 2023

Abstract
Globally, wastes from agricultural and industrial activities cause water pollution. Pollutants such as microbes, pesticides, and heavy metals in contaminated water bodies beyond their threshold limits result in several diseases like mutagenicity, cancer, gastrointestinal problems, and skin or dermal issues when bioaccumulated via ingestion and dermal contacts. Several technologies have been used in modern times to treat wastes or pollutants such as membrane purification technologies and ionic exchange methods. However, these methods have been recounted to be capital intensive, non-eco-friendly, and need deep technical know-how to operate thus, contributing to their inefficiencies and non-efficacies. This review work evaluated the application of Nanofibrils-protein for the purification of contaminated water. Findings from the study indicated that Nanofibrils protein is economically viable, green, and sustainable when used for water pollutant management or removal because they have outstanding recyclability of wastes without resulting in a secondary phase-pollutant. It is recommended to use residues from dairy industries, agriculture, cattle guano, and wastes from a kitchen in conjunction with nanomaterials to develop nanofibrils protein which has been recounted for the effective removal of micro and micropollutants from wastewater and water. The commercialization of nanofibrils protein for the purification of wastewater and water against pollutants has been tied to novel methods in nanoengineering technology, which depends strongly on the environmental impact in the aqueous ecosystem. So, there is a need to establish a legal framework for the establishment of a nano-based material for the effective purification of water against pollutants.
Boron nitride nanotube–salt–water hybrid:crystalline precipitation
Authors: Ge Yanyan , Zhang Cuicui , Zhu Xueru , Li Hua , Wang Yongjian 
Published: February 2023

Abstract
Molecular dynamics simulation is used to study the transport characteristics of NaCl solution in boron nitride nanotubes (BNNTs). It presents an interesting and well-supported MD study of the crystallization of NaCl from its water solution under the confinement of a 3 nm thick boron nitride nanotube with varied surface charging conditions. The results of the molecular dynamics simulation indicate that NaCl crystallization occurs in charged BNNTs at room temperature when the concentration of NaCl solution reaches about 1.2 M. The reason for this phenomenon is as follows: when the number of ions in the nanotubes is high, the double electric layer that forms at the nanoscale near the charged wall surface, the hydrophobicity of BNNTs, and the interaction among ions cause ions to aggregate in the nanotubes. As the concentration of NaCl solution increases, the concentration of ions when they aggregate in the nanotubes reaches the saturation concentration of the NaCl solution, resulting in the crystalline precipitation phenomenon.
Energy decay for wave equations with nonlinear damping and space-time coefficient in

Rn
Authors: Ogbiyele Paul A , Arawomo Peter O 
Published: February 2023

Abstract
In this paper, we consider the following nonlinear wave equation

u

t
t

−
Δ
u
+
a
(
t
,
x
)

|

u
t

|

m
−
1

u
t

+

|

u

|

p
−
1

u
=
0
,
t
>
0
,
x
∈

R

n

u
(
0
,
x
)
=

u
0

(
x
)
,

u
t

(
0
,
x
)
=

u
1

(
x
)
x
∈

R

n

and obtain optimal energy decay estimates under suitable assumptions on the space-time nonlinear damping coefficient a, where m satisfies

1
<
m
⩽

n
+
2

n
−
2

. We establish a new Liapunov type function to obtain energy decay estimates in the case of nonlinear damping instead of the Kormonik lemma.
Multi-valued random dynamics of partly dissipative reaction–diffusion system with discontinuous nonlinearity on

RN
Authors: Ma Zhong-Xin , Zhao Jia-Cheng 
Published: February 2023

Abstract
This paper is devoted to studying a system consisting of a reaction–diffusion equation with multi-valued right-hand side and an ordinary differential equation in absence of dissipation term, which is defined on the whole space

R

N

. The system is driven by time-dependent forces and coloured noise with nonlinear diffusion. We first establish the global existence of strong/mild solutions for initial-value problems. The measurability of solution map with respect to sample points and initial values is then obtained via the upper semicontinuity, which indicates that these solutions define a (non-autonomous) multi-valued random dynamical system. Finally, we prove the existence of pullback attractor for the dynamical system.
Edge effect reduction of high-resolution PET detectors using LYSO and GAGG phoswich crystals
Authors: Liu Zheng , Mungai Samuel , Niu Ming , Kuang Zhonghua , Ren Ning , Wang Xiaohui , Sang Ziru , Yang Yongfeng 
Published: February 2023

Abstract

Objective. Small-animal positron emission tomography (PET) is a powerful preclinical imaging tool in animal model studies. The spatial resolution and sensitivity of current PET scanners developed for small-animal imaging need to be improved to increase the quantitative accuracy of preclinical animal studies. This study aimed to improve the identification capability of edge scintillator crystals of a PET detector which will enable to apply a crystal array with the same cross-section area as the active area of a photodetector for improving the detection area and thus reducing or eliminating the inter-detector gaps. Approach. PET detectors using crystal arrays with mixed lutetium yttrium orthosilicate (LYSO) and gadolinium aluminum gallium garnet (GAGG) crystals were developed and evaluated. The crystal arrays consisted of 31 × 31 array of 0.49 × 0.49 × 20 mm3 crystals; they were read out by two silicon photomultiplier arrays with pixel sizes of 2 × 2 mm2 that were placed at both ends of the crystal arrays. The second or first outermost layer of the LYSO crystals was replaced by GAGG crystals in the two crystal arrays. The two crystal types were identified using a pulse-shape discrimination technique to provide better edge crystal identification. Main results. Using the pulse shape discrimination technique, almost all (except for a few edge) crystals were resolved in the two detectors; high sensitivity was achieved by using the scintillator array and the photodetector with the same areas and achieved high resolution by using crystals with sizes equal to 0.49 × 0.49 × 20 mm3. Energy resolutions of 19.3 ± 1.8% and 18.9 ± 1.5%, depth-of-interaction resolutions of 2.02 ± 0.17 mm and 2.04 ± 0.18 mm, and timing resolutions of 1.6 ± 0.2 ns and 1.5 ± 0.2 ns were achieved by the two detectors, respectively. Significance. In summary, novel three-dimensional high-resolution PET detectors consisting of a mixture of LYSO and GAGG crystals were developed. The detectors significantly improve the detection area with the same photodetectors and thus improve the detection efficiency.
In situ probing of atmospheric-pressure warm air glow discharge for nitrogen fixation by multiple laser spectroscopies
Authors: Shu Zhan , Qiao Junjie , Yang Qi , Song Yijia , Wang Dazhi , Xiong Qing 
Published: February 2023

Abstract
The fixation of atmospheric nitrogen into valuable compounds through reactive plasma processes has attracted intense interests due to its easy operation and compatibility with distributed renewable energy sources. However, practical implementation of plasma-assisted nitrogen fixation is hampered because of its relatively low throughput, which is dominantly limited by the unclear underlying mechanisms. In this study, effort was focused on the in situ production of key species in a DC-driven warm air glow discharge at atmospheric pressure with the help of advanced laser spectroscopic diagnostics. Laser Rayleigh scattering was applied to determine the gas temperature distribution in the discharge column. And mid-infrared quantum cascade laser absorption spectroscopy and one/two-photon absorption laser-induced fluorescence were performed on molecular nitric oxide (NO), atomic oxygen and nitrogen (O, N) for their absolute densities in the discharge. It is found that the spatial distributions of gas temperature, O and N atoms show peaks in the hot discharge center. In contrast, a hollow ‘doughnut’ shape characterized by the NO molecule was observed, particularly under conditions of high discharge current but low airflow rate. The steady-state simulation shows that the hollow pattern of NO is dominantly induced by the radial diffusion of species due to the steep spatial gradient of gas temperature in the discharge cross-section. Moreover, the reverse conversion by atomic N leads to a negative effect on the NO synthesis, especially at the discharge center where the N density and gas temperature are high. From the steady-state modeling, a similar hollow distribution of NO2 was depicted in the air glow discharge. These results demonstrate the strong dependence on atomic O for the major formation process of NO, and the importance of suppressing the reverse paths dominated by atomic N for higher NO production in the studied warm air plasma.
Effect of negative triangularity on peeling-ballooning instability
Authors: Qin Chenchen , Mou Maolin , Chen Shaoyong , Li Yongjian , Luo Yang , Zhu Limin , Dong Liangkang , Tang Changjian 
Published: February 2023

Abstract
Experiments have achieved high confinement discharges in tokamaks with a negative triangularity (NT) plasma shape accompanied by a lower pedestal and smaller and more frequent edge localized modes (ELMs) compared with positive triangularity (PT). Some existing theories emphasize the linear instability variations result from the change of pedestal. However, NT can directly bring significant changes on magnetic field structures which may also influence the instability of ELMs. Based on a series of equilibria constructed with different triangularities and pressure profiles, the influence of NT on peeling-ballooning mode (P–B mode) is investigated. It is found that NT can increase the growth rates of low to intermediate n (toroidal mode number) modes in the linear stage and lead to a larger pedestal collapse in the nonlinear stage if its pressure profile is the same with the PT shape. Further analyses demonstrate that NT enlarges the unfavorable curvature area, which provides stronger driving source and larger unstable region for the instability. Meanwhile, the diamagnetic effect and local magnetic shear helps to stabilize high n modes in the linear phase, and the E × B shearing rate at the top of the pedestal contributes to suppress the transport of turbulence into the plasma core in the nonlinear phase for the NT shape. What’s more, further simulations with different pedestal heights demonstrate that there exists a threshold value of pressure ratio, below which the ELM energy loss in NT shapes can be smaller than that in PT shapes, suggesting that the smaller energy loss with NT in experiment mainly results from the lower pedestal heigh. The results reveal behaviors of P–B modes and provide possible mechanisms for the phenomenon of lower pedestal height with negative triangularities in experiments.
First-principles study of crystal structure search, stability and mechanical property of magnesium-lithium binary system
Authors: Zhang Xiaozhe , Huang Yan , He Xiaoguang , Sun Shaodong 
Published: February 2023

Abstract
In this paper, the energetically stable and metastable crystal structures of Mg-Li binary system are searched throughout all possible Mg concentrations by using the first-principles calculations based on density functional theory (DFT). Three stable structures are found at compositions LiMg, LiMg2 and Li2Mg3. One metastable structure is found at composition LiMg3. The formation energy, phonon spectrum, and elastic constants are calculated to evaluate the energy, dynamic and elastic stabilities, respectively. At zero temperature, both the elastic moduli (include bulk modulus B, shear modulus G, Young’s modulus E, the Poisson’s ratio ν and B/G ratio) as a function of the Mg concentration in Mg-Li binary system and the spatial direction dependences of elastic moduli are analyzed. The temperature dependents of bulk modulus and thermal expansion coefficient are also analyzed to investigate the high-temperature mechanical properties of Mg-Li binary system. With the increase of temperature, the bulk modulus of Mg-Li alloys gradually decreases and the thermal expansion coefficient gradually increases. And the calculated results also show that LiMg2 can maintain excellent mechanical strength and mechanical stability at high temperature, and has the potential of application in the high-temperature fields.
Observations of xenon spectra on the EAST x-ray crystal spectrometer for high-temperature plasma diagnostics
Authors: Lu Dian , Wang Fudi , Delgado-Aparicio Luis F. , Yang Yang , Hill Kenneth , Bae Cheonho , Bitter Manfred , Fu Jia , Zhang Hongming , Shen Yongcai , Jin Yifei , Liu Haijing , He Liang , Fu Shengyu , Zang Qing , Lyu Bo 
Published: February 2023

Abstract
The Xe44+ 2.7203 Å line, which has been proposed as one of the diagnostic lines for the x-ray imaging crystal spectrometer on ITER, is observed on the EAST tokamak together with its several satellite lines. The observations are made under high electron temperature (T

e
) conditions (core T

e
> 5 keV). Most of the observed xenon lines are identified by comparing the experiment results with the atomic simulation results. The first ion temperature measurements made by the xenon spectra on EAST are also reported in this article. These xenon spectra observations contribute to the justification for using xenon as the diagnostic impurity in x-ray crystal spectrometers in future reactor-scale high-temperature plasmas.
Features of the combined technology based on laser metal deposition with layered laser heat treatment
Authors: Zavalov Y N , Dubrov A V , Rodin P S , Makarova E S , Dubrov V D 
Published: February 2023

Abstract
The results of combined using of laser metal deposition technology with layer-by-layer laser heat treatment technology are presented and the experimental setup is described to unite the laser metal deposition technology with layer-by-layer laser remelting and/or laser surface hardening implementation. The layers formed at the stages of laser metal deposition and additional layer-by-layer laser heat treatment alternate in the material. The ratio between the thicknesses of the layers obtained during crystallization at the laser metal deposition stage and at the laser remelting stage is shown to vary widely depending on the technological parameters. The surface temperature of the irradiated layer is maintained in laser surface hardening mode in the range of 1100 °C – 1400 °C with present laser power function. It is proposed to use this mode for local structural-phase transformation of the material.
Study and comparison of resist characteristics for different negative tone electron beam resists
Authors: Andok R , Vutova K , Bencurova A , Kostic I , Koleva E 
Published: February 2023

Abstract
In this work, four types of negative electron beam resists are investigated. Electron beam lithography (EBL) experiments were conducted using EBL system ZBA23 (Raith) with the variable-shaped electron beam cross-section at 40 keV electron energy. Important electron beam resist characteristics such as sensitivity, dissolution rate, aspect ratio and sidewall developed profiles in the chemically amplified resist (CAR) SU-8 2000, non-CARs ma-N 2410 and ARN-7520, and inorganic negative resist HSQ XR-1514 are studied and compared. This study was motivated by the selection of a suitable resist for practical use such as large area gratings fabrication for optoelectronics.
Study of double electron beam refining at melting of hafnium metal sponge
Authors: Vutova K , Vassileva V , Ratheesh R , Reddy R C , Kumar A 
Published: February 2023

Abstract
The possibility of the refining of hafnium metal sponge by e-beam double melting process is studied in this work. For this purpose, the effect of kinetic and thermodynamic parameters on the behavior of the impurities present in the base metal and their influence on the microstructure of the samples produced after double electron beam refining are investigated. The vapor (partial) pressure of hafnium, the controlled metallic inclusions (impurities) and their oxides as well as the relative volatility for the inclusions in the investigated hafnium material were evaluated. The process efficiency and the degree of refining with respect to the controlled impurities for each technological mode at double refining of hafnium sponge material were assessed based on thermodynamic analysis and conducted experiments.
Development of model-based simulation and optimization software for electron beam melting and refining
Authors: Koleva E , Koleva L , Tsonevska Ts 
Published: February 2023

Abstract
In this paper the development of a software for electron beam melting and refining (EBMR) of different materials is presented. It has the following functional characteristics: simulation of the temperature distributions in the cast ingots, investigation and optimization of the form of the liquid pool during the process of EBMR and estimation of the inclusion refining rates, depending on the EBMR process parameters. The temperature distributions in the cast ingots are simulated by the implementation of quasi steady-state two-dimensional heat model and three-dimensional time-dependent thermal model for different refined metals. Empirical models are estimated, integrated in the developed software and used for the investigation of the molten pool geometry parameters, the content of impurities after the electron beam refining process, refining rate, overall inclusion removal efficiency and the material losses. The influence of EBMR process parameters such as electron beam power, casting velocity, refining time, and electron beam radius are considered. Multicriterial optimization software functions can be implemented for solving concrete technological requirements for each practical use-case.
3-D analysis of electron beam shape at target plane through parametric variation of an indirectly heated cathode-based electron gun
Authors: Goel V , Roy A , Maiti N 
Published: February 2023

Abstract
In this paper, a detailed 3-D analysis of the electron beam shape at the target plane of high power (60 kW, 60 kV, 1 A) 2700-bent indirectly heated cathode-based electron gun has been successfully carried out. This work will help analyse individual electron beam trajectories in the actual 3-D plane to ensure optimum electron beam bending and focusing at the target plane. Moreover, due to the presence of an additional electrode in an indirectly heated cathode-based electron gun i.e., a filament which is resistively heated and an indirectly heated solid cathode (heated through electron bombardment), this analysis becomes even more imperative. The work carried out in this paper will ensure better performance, characterization, and optimization of the 2700-bent indirectly heated cathode-based electron gun. Rigorous simulation work has been carried out by performing 3-D electrostatic, electromagnetic, and particle tracking simulations using CST Studio Particle Tracking Module. Adaptive mesh refinement has been utilized to ensure high accuracy of the results obtained. An optimum filament-solid cathode interspacing was found, using strip-shaped filament by providing a higher negative potential to the grid cup. It led to a well-focused 2700-bent electron beam, exhibiting minimum electron beam emittance at the target plane.
PDMS-based porous membrane for medical applications: design, development, and fabrication
Authors: Keshtiban Mohsen Mashhadi , Zand Mahdi Moghimi , Ebadi Amirali , Azizi Zahra 
Published: February 2023

Abstract
Organ-on-a-chip (OoC) is one of the most popular microfluidic chips and possesses various industrial, biomedical, and pharmaceutical applications. So far, many types of OoCs with different applications have been fabricated, most of which contain porous membranes useful as cell culture substrates. One of the challenging parts of OoC’s chips is porous membrane fabrication, making it a complex and sensitive process, which is an issue in microfluidic design. These membranes are made of various materials, the same as biocompatible polymer polydimethylsiloxane (PDMS). Besides OoC, these PDMS membranes can be applied in diagnosis, cell separating, trapping, and sorting. In the present study, a new approach has been presented to design and fabricate an efficient porous membrane in terms of time and cost. The fabrication method has fewer steps than previous techniques and employs more conventional approaches. The presented method for membrane fabrication is functional and a novel way to continue producing this product with a single mold and peeling off the membrane on each try. Merely one sacrificial layer (polyvinyl alcohol) and an O2 plasma surface treatment have been used for fabrication. Surface modification and sacrificial layer on the mold ease the peeling of the PDMS membrane. Transferring process of the membrane to the OoC device is explained, and a filtration test is presented to show the functionality of the PDMS membranes. Cell viability is investigated by MTT assay to ensure the PDMS porous membranes are suitable for microfluidic devices. Also, cell adhesion, cell count, and confluency are analyzed, showing almost the same results for the PDMS membranes and the control samples.