bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of the adjustable EMBr on the asymmetric flow in a thin slab caster with a misaligned SEN
Authors: Vakhrushev A , Karimi-Sibaki E , Wu M , Ludwig A , Nitzl G , Tang Y , Hackl G , Watzinger J , Kharicha A 
Published: May 2023

Abstract
The thin slab casting (TSC) of steel is a type of the continuous casting (CC) with a narrow funnel-shaped mold, characterized by the rapid solidification and fast production rates. A highly turbulent flow impacts on a growing solid shell due to the constant feeding of the fresh hot melt. That strongly affects the solidification profiles and final quality of the TSC slabs. The presented work numerically investigates the solidification inside the TSC mold with the asymmetric flow pattern caused by the misalignment (tilting) of the submerged entry nozzle (SEN). These effects were considered with and without the applied electromagnetic brake (EMBr). The influence of the adjustable EMBr on the asymmetric flow and solidification profiles including turbulent and magnetohydrodynamic (MHD) effects were studied. During consistent series of simulations, the EMBr was varied between the magnetic poles and the time-averaged velocity and temperature fields were collected. The results showed that symmetric EMBr of a local type could partially improve the asymmetry. An optimal braking scenario was found for the casing speed of 5.5 m/min and maximum EMBr value of 180 mT. The solidification and MHD models including turbulence were developed using OpenFOAM®.
Model of multiphase flow, superheat transport, and particle capture in a steel continuous caster
Authors: Liang Mingyi , Cho Seong-Mook , Ruan Xiaoming , Thomas Brian G 
Published: May 2023

Abstract
A model of turbulent multiphase flow, heat transfer, and particle entrapment during continuous casting of steel is presented. The model includes the top 7m of the vertical and curved strand, and considers the effects of argon gas injection and thermal buoyancy. RANS model flow results are compared with LES. Lagrangian particle transport through the Eulerian-Eulerian multiphase flow field from the k-ɛ RANS model is based on random walk and features advanced particle capture criteria, improved from previous work by including anisotropic turbulent velocity fluctuations near the walls. Particle capture via 3 mechanisms is included: capture by solidified hooks at the meniscus, entrapment between dendrites, and engulfment by surrounding large particles. The fluid flow and bubble/inclusion capture results are validated with plant measurements, including nail board dipping tests and ultrasonic tests of particle locations, and good agreement is seen. The superheat has negligible effect on flow in the mold region but causes complex flow in the lower strand by creating multiple recirculation zones due to the thermal buoyancy. With high (30 K) superheat, this leads to less penetration, and slightly fewer and shallower capture of particles. Lower (10 K) superheat may enable significant top surface freezing, leading to very large internal defect clusters. Lower superheat also leads to deeper meniscus hooks, and more surface capture. Capture bands occur near the transition from vertical to curved, where downward liquid flow velocity balances the particle terminal velocity.
Quantifying X-ray diffractometer precision for measurement of dislocation density and the evolution of defect structures during solidification of additive manufacturing powders
Authors: Azersky C , Jeon S , Settens C , Fakhrul M , Matson D 
Published: May 2023

Abstract
In this work, the Phillips PW 3020 X’Pert Diffractometer and PANalytical X’Pert Pro MPD X-ray Diffractometer were used to perform in-situ monitoring of quenched microstructures to define the defect evolution of Inconel 718 additive manufacturing powder. Dislocation density analysis based on X-ray Diffraction (XRD) measurement is sensitive to XRD peak broadening. The X-ray line profile is affected by the instrumental effects of the diffractometer, so quantifying and analyzing XRD instrument performance is important for accurate dislocation density analysis. The average measurement bias of the Phillips diffractometer was found to be -1.5490·10−3 Å while the precision was found to be 6.1000·10−5 Å. The average measurement bias of the PANalytical diffractometer was found to be -1.7633·10−4 Å while the precision was found to be 7.6917·10−5 Å. The average dislocation density calculated from the data was 3.93·1014 m−2 for the smaller particle size range and 2.58·1014 m−2 for the larger particle size range. The number of diffraction peaks utilized in dislocation density analysis was found to be a more significant factor than the instrumental differences. This work confirmed that differences in defect structure density can be observed across differently sized particles sourced from additive manufacturing powder.
Effects of instabilities on the properties of ingots made by the ESR and VAR processes
Authors: Hans S , Mitchell A 
Published: May 2023

Abstract
The ESR and VAR processes are very often carried out under less-than-ideal conditions where the procedure involves inadvertent instabilities such as interruptions in metal flow or abrupt changes in the process heat balance. In this work we demonstrate the effects of typical examples of such instability as related to the remelting processes. It is suggested that a major direction in modelling development should be towards an understanding of the extent to which instability can be tolerated relative to the product requirements. Such an understanding would assist in the establishment of suitable quality standards governing the production of high-quality alloys.
Modeling of oxide inclusions in steel casting
Authors: Donahue R , Hardin R , Beckermann C 
Published: May 2023

Abstract
A model is presented that predicts the amount and location of oxide inclusions in steel castings. A number and size distribution of inclusions, defined about a mean diameter, enters the casting system at its inlet during the filling process and are transported to their final locations in the casting. Model parameters for inclusion density, drag and wall friction are used to calculate the motion and locations of the oxide particles. Model results are presented to study the effects of casting shape and surface orientation on the final inclusion locations and distributions within castings. These results are compared with inclusion tracking experiments where the geometry of the gating system and orientation of casting cope surfaces affect the final distribution of inclusions in the castings. Measured and simulated inclusion area percent coverage, inclusion count and mean diameter are compared for a range of modelling parameters and inclusion size distributions. The size and number distribution at the casting system inlet, and other model parameters, are determined which provide the best agreement between measured and simulated inclusion area, count, and size.
Simulation of dendritic deformation induced by convection in alloy solidification
Authors: Yang Luwei , Ren Neng , Li Jun , Xia Mingxu , Dong Hongbiao , Li Jianguo 
Published: May 2023

Abstract
Dendritic deformation induced by convection of thermal fluid is one of the factors leading to dendrite fragmentation and plays a crucial role in grain structure of alloy, which lacks in-depth understanding. In this paper, we simulate the flow-induced mechanical deformation of dendrites during the solidification of Al-4.5wt.%Cu alloy by combining the cellular automaton-finite volume method (CA-FVM) for the dendrite growth and the finite element method (FEM) for handling the dendritic deformation with the complex boundary conditions given by CA-FVM results. It shows that the dendritic deformation strongly depends on the flow velocities of melt and dendritic morphology. The dendrites can undergo visible bending above the critical flow velocities for dendrite yield (ranging from 0.023 m/s to 0.126 m/s as the inlet velocity increases) and the von Mises stress increases as the flow is enhanced during the growth process.
On the occurrence of buoyancy-induced oscillatory growth instability in directional solidification of alloys
Authors: Barbera Josep Maria , Isensee Thomas , Tourret Damien 
Published: May 2023

Abstract
Recent solidification experiments identified an oscillatory growth instability during directional solidification of Ni-based superalloy CMSX4 under a given range of cooling rates. From a modeling perspective, the quantitative simulation of dendritic growth under convective conditions remains challenging, due to the multiple length scales involved. Using the dendritic needle network (DNN) model, coupled with an efficient Navier-Stokes solver, we reproduced the buoyancy-induced growth oscillations observed in CMSX4 directional solidification. These previous results have shown that, for a given alloy and temperature gradient, oscillations occur in a narrow range of cooling rates (or pulling velocity, V
p
) and that the selected primary dendrite arm spacing (Λ) plays a crucial role in the activation of the flow leading to oscillations. Here, we show that the oscillatory behavior may be generalized to other binary alloys within an appropriate range of (V
p
,Λ) by reproducing it for an Al-4at.%Cu alloy. We perform a mapping of oscillatory states as a function of V
p
and Λ, and identify the regions of occurrence of different behaviors (e.g., sustained or damped oscillations) and their effect on the oscillation characteristics. Our results suggest a minimum of V
p
for the occurrence of oscillations and confirm the correlation between the oscillation type (namely: damped, sustained, or noisy) with the ratio of average fluid velocity

V
¯

over V
p
. We describe the different observed growth regimes and highlight similarities and contrasts with our previous results for a CMSX4 alloy.
Diffuse modelling of pearlite growth in Calphad-coupled multicomponent multi-phase-field simulations
Authors: Eiken J , Böttger B , Apel M 
Published: May 2023

Abstract
During cooling of steels and cast irons, austenite can decompose by a eutectoid transformation into pearlite, a two-phased mixture of ferrite and cementite. Since the internal lamellar structure is commonly too fine to be distinguished on the scale of the austenite grain structure, pearlite is often modelled as an effective, pseudo-single phase. Such a pragmatic treatment would also be desirable to reduce the computational effort of large-scale multi-phase-field simulations, but a fundamental hindrance is that no consistent thermodynamic description exists for effective pearlite in multicomponent databases. Alternatively, we here propose to model pearlite as diffuse mixture of two phases with individual local fractions and concentrations, such that solute partitioning and thermodynamic driving forces can be consistently derived from standard Calphad databases. The essential computational advantage is that only the outer interfaces of the pearlite nodules have to be numerically resolved, which allows for increased grid spacing and time-steps. The impact of the unresolved lamellar structure on the curvature undercooling is modelled analytically based on a characteristic spacing, which may be calibrated either experimentally or by small-scale simulations. The potential and the limitations of the new approach, implemented in the frame of the Micress® software, shall be discussed.
Phase-field lattice Boltzmann simulation of three-dimensional settling dendrite with natural convection during nonisothermal solidification of binary alloy
Authors: Sakane S , Aoki T , Takaki T 
Published: May 2023

Abstract
Understanding the motion and growth behaviors of equiaxed dendrites during solidification is important for predicting macrosegregation. In this study, we develop a phase-field lattice Boltzmann (PF-LB) simulation method for the settling and growth of an equiaxed dendrite during the nonisothermal solidification of a binary alloy. The PF-LB computations are accelerated by employing parallel computation using multiple graphic processing units (GPUs) and the octree block-structured adaptive mesh refinement method, which incorporates multiple mesh and time increment methods. By using the developed method, we can simulate the three-dimensional long-distance settling dendrite while considering the effects of latent heat release and natural convection. From the simulation results, we confirm that the natural convection due to the high solute concentration around a dendrite reduces the settling velocity. In addition, we observe that the temperature increase owing to latent heat release slows dendrite growth, which in turn slightly slows the settling velocity. From these results, we confirm that the effects of latent heat release and natural convection are not negligible in the quantitative evaluation of settling dendrites.
Investigation of diffusive grain interactions during equiaxed dendritic solidification
Authors: Chirouf Abdelhalim , Appolaire Benoît , Finel Alphonse , Bouar Yann Le , Založnik Miha 
Published: May 2023

Abstract
Grain growth during the solidification of an alloy is accompanied by the enrichment of the surrounding liquid phase in chemical species. The resulting diffusion fields induce interactions between the grains that are strongly dependent on their spatial arrangement. The influence of these diffusive interactions is not limited to the shapes and sizes of grains but also controls the overall kinetics of the transformation. In this study we investigate the role of the spatial arrangement of equiaxed grains in the average growth kinetics of an ensemble of grains. We perform full-field simulations of different grain ensembles using the mesoscopic grain envelope model (GEM). We show that the growth kinetics of randomly arranged ensembles is fundamentally different from that of periodic arrangements. We provide an explanation of this difference through analyses of the behaviour of individual grains in their local neighbourhood, defined by a Voronoi tessellation. Finally, we compare the full-field GEM simulations to state-of-the-art mean-field models and we point out the limitations of the latter in the prediction of dendritic growth.
Phase field model of microstructure formation during cooling slope slurry generation of novel Al-15Mg2Si-4.5Si composite
Authors: Das Prosenjit 
Published: May 2023

Abstract
The present study discusses the development of a two-dimensional phase field model of semi solid microstructure evolution of the novel Al-15Mg2Si-4.5Si composite during cooling slope rheoprocessing. The superheated melt of the said composite undergoes partial solidification during its shear flow over the slope free surface, prior to get collected within the isothermal slurry holding furnace. Seed undercooling based nucleation model is adopted in the present PF model to simulate slurry microstructure of the composite. Experimentally determined cooling rate values are considered to simulate slurry microstructure for different process conditions. Micrographs of melt samples collected during experimentation establishes the developed PF model as an accurate microstructure prediction tool for the composite slurry. Apart from morphological features such as size and degree of sphericity values of the evolving primary Mg2Si and α-Al grains, the model predictions includes melt temperature as well as solid content at any given instant of slurry processing.
Reconstruction of dendritic growth by fast tomography and phase field filtering
Authors: Yasuda H , Nishiguchi A , Xue H , Nonomura M , Nakano K , Katsube R , Narumi T , Takaki T 
Published: May 2023

Abstract
Three dimensional models of dendritic structures during solidification are valuable for building physical models, validating simulated results, estimating some properties such as permeability in the mushy, simulating semisolid deformation and so on. Thus, it is of interest to observe microstructure evolution in situ. Time-resolved tomography combined with X-ray diffraction has allowed us to observe the evolution of dendritic structures and to measure crystallographic orientation in situ. Reconstruction still proves to be difficult for some alloy systems because of the tradeoff between time and spatial resolution. This paper demonstrates the reconstruction of dendritic structures for three different alloy systems (Al-10mass%Cu alloy with a diameter of 4 mm, CrMnFeCoNi alloy with 1 mm, and Zn-4mass%Al alloy with 0.7 mm). The observations were performed in a synchrotron radiation facility SPring-8. A filter using a phase field model was introduced to reconstruct the three-dimensional images. Parameters used in the filtering were consistently determined based on the raw reconstruction images. Evaluation of solid-liquid interface area and curvature was significantly improved by the filter. For the Al-Cu alloy, a three-dimensional model containing approximately 300 million voxels was obtained. For the CrMnFeCoNi alloys, the preferred growth direction <100> was confirmed by tomography and X-ray diffraction. For the Zn-Al alloy, the observed 14 growth directions were not simply defined by the crystallographic orientations, although the directions were consistent with the hexagonal symmetry. This study verifies that time resolved tomography, X-ray diffraction and the filter using a phase field model provide three dimensional models for light metal alloys with rather large diameters and 3d transition-metal alloys with rather large X-ray absorption coefficients. The models are expected to be used for further studies.
Impact of fin width on nano scale tri-gate FinFET including the quantum mechanical effect
Authors: Panchanan Suparna , Maity Reshmi , Baidya Achinta , Maity Niladri Pratap 
Published: May 2023

Abstract
An inversion charge-based threshold voltage model is proposed for 10 nm channel length Tri-gate (TG) FinFET. The variation threshold voltage has been studied with respect to fin width

W

f
i
n

for different fin height

H

f
i
n

and channel length

L

.

The effect of width quantization has been explained with the help of the quantum mechanical effect (QME). A precise comparison of threshold voltage in terms of classical mechanics and quantum mechanics depicts the presence of width quantization in short channel device. The improvement of the short channel effects (SCEs), like subthreshold swing (SS), drain-induced barrier lowering (DIBL) and threshold voltage roll off have been studied. The impact of channel length to fin width ratio on DIBL and

S
S

has been examined. The improvement of the SCEs at the same oxide thickness has been observed for high-k dielectric material. The potential and effect of hafnium oxide (HfO2) have been discussed and validated using technology computer-aided design (TCAD) simulation.
WMSA 2: a multiple DNA/RNA sequence alignment tool implemented with accurate progressive mode and a fast win-win mode combining the center star and progressive strategies
Authors: Chen Juntao , Chao Jiannan , Liu Huan , Yang Fenglong , Zou Quan , Tang Furong 
Published: May 2023

Abstract
Multiple sequence alignment is widely used for sequence analysis, such as identifying important sites and phylogenetic analysis. Traditional methods, such as progressive alignment, are time-consuming. To address this issue, we introduce StarTree, a novel method to fast construct a guide tree by combining sequence clustering and hierarchical clustering. Furthermore, we develop a new heuristic similar region detection algorithm using the FM-index and apply the k-banded dynamic program to the profile alignment. We also introduce a win-win alignment algorithm that applies the central star strategy within the clusters to fast the alignment process, then uses the progressive strategy to align the central-aligned profiles, guaranteeing the final alignment's accuracy. We present WMSA 2 based on these improvements and compare the speed and accuracy with other popular methods. The results show that the guide tree made by the StarTree clustering method can lead to better accuracy than that of PartTree while consuming less time and memory than that of UPGMA and mBed methods on datasets with thousands of sequences. During the alignment of simulated data sets, WMSA 2 can consume less time and memory while ranking at the top of Q and TC scores. The WMSA 2 is still better at the time, and memory efficiency on the real datasets and ranks at the top on the average sum of pairs score. For the alignment of 1 million SARS-CoV-2 genomes, the win-win mode of WMSA 2 significantly decreased the consumption time than the former version. The source code and data are available at https://github.com/malabz/WMSA2.
CIForm as a Transformer-based model for cell-type annotation of large-scale single-cell RNA-seq data
Authors: Xu Jing , Zhang Aidi , Liu Fang , Chen Liang , Zhang Xiujun 
Published: May 2023

Abstract
Single-cell omics technologies have made it possible to analyze the individual cells within a biological sample, providing a more detailed understanding of biological systems. Accurately determining the cell type of each cell is a crucial goal in single-cell RNA-seq (scRNA-seq) analysis. Apart from overcoming the batch effects arising from various factors, single-cell annotation methods also face the challenge of effectively processing large-scale datasets. With the availability of an increase in the scRNA-seq datasets, integrating multiple datasets and addressing batch effects originating from diverse sources are also challenges in cell-type annotation. In this work, to overcome the challenges, we developed a supervised method called CIForm based on the Transformer for cell-type annotation of large-scale scRNA-seq data. To assess the effectiveness and robustness of CIForm, we have compared it with some leading tools on benchmark datasets. Through the systematic comparisons under various cell-type annotation scenarios, we exhibit that the effectiveness of CIForm is particularly pronounced in cell-type annotation. The source code and data are available at https://github.com/zhanglab-wbgcas/CIForm.
A-318 SURGICAL APPROACH TO METASTASIZED NEUROENDOCRINE TUMOURS OF THE SMALL INTESTINE: A RETROSPECTIVE EUROPEAN MULTICENTRE STUDY (EUROCRINE® Study Group)
Authors: Lozan O , Musholt T 
Published: May 2023

Abstract

Background
At the time of the diagnosis, up to 60% of NETs are already metastasised. However, due to the rare prevalence and lack of prospective studies, suitable treatment guidelines have yet been established.

Methods
In a retrospective, multi-center, European study, using the EUROCRINE® database, 144 palliative surgeries due to SI-NETs were selected, divided into 3 groups, and analysed. Based on the time of the last follow-up, stage, grading, and surgical treatment, Kaplan-Meier survival curves and Log-Rank tests were used to compare the outcome, overall survival, and quality of life.
The 3 groups are as followed:

Results
Out of 144 surgeries, 9 were performed in emergency settings (A). In 42 only the primary tumour was resected (B). The remaining 93 cases reduced the tumour mass (C). (A) did not show a poorer quality of life in the short term, only one case having early onset postoperative complications, compared to 9 (B) and 22 (C). In 4 cases (A) a R0 Resection was obtained, compared to 10 (B) and 46 (C). 2 cases (A) remained tumour-free in the first follow-up, compared to 3 (B) and 10 (C). No patients were deceased until the first follow-up in (A), 1 patient died shortly after resection in (B), and 1 in (C). As many patients were lost in the long-term follow-ups, overall survival could not be estimated.

Conclusion
(A) has a comparable mortality rate to (B) or (C)
Careful patient selection can greatly improve outcomes.
A more thorough follow-up is required to better estimate the survival rates in 5 or 10 years.