bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global existence of weak solutions to viscoelastic phase separation: part II. Degenerate case
Authors: Brunk Aaron , Lukáčová-Medvid’ová Mária 
Published: June 2022

Abstract
The aim of this paper is to prove global in time existence of weak solutions for a viscoelastic phase separation. We consider the case with singular potentials and degenerate mobilities. Our model couples the diffusive interface model with the Peterlin–Navier–Stokes equations for viscoelastic fluids. To obtain the global in time existence of weak solutions we consider appropriate approximations by solutions of the viscoelastic phase separation with a regular potential and build on the corresponding energy and entropy estimates.
Doubly nonlinear Schrödinger ground states on metric graphs
Authors: Boni Filippo , Dovetta Simone 
Published: June 2022

Abstract
We investigate the existence of ground states at prescribed mass on general metric graphs with half-lines for focussing doubly nonlinear Schrödinger equations involving both a standard power nonlinearity and delta nonlinearities located at the vertices. The problem is proved to be sensitive both to the topology and to the metric of the graph and to exhibit a phenomenology richer than in the case of the sole standard nonlinearity considered by Adami et al (2015 Calc. Var.
54 743–61; 2016 J. Funct. Anal.
271 201–23). On the one hand, we identify various topological features responsible for existence/non-existence of doubly nonlinear ground states in specific mass regimes. On the other hand, we describe the role of the metric in determining the interplay between these different topological properties.
Development and implementation of an automatic air delineation technique for MRI-guided adaptive radiation therapy
Authors: Ahunbay Ergun , Parchur Abdul K , Paulson Eric , Chen Xinfeng , Omari Eenas , Li X Allen 
Published: June 2022

Abstract

Objective. Auto-delineation of air regions on daily MRI for MR-guided online adaptive radiotherapy (MRgOART) of abdominal tumors is challenging since the air packets occur randomly and their MR intensities can be similar to some other tissue types. This work reports a new method to auto-delineate air regions on MRI. Approach. The proposed method (named DIFF method) consists of (1) generating a combined volume V

comb
, which is a union of the air-containing organs on a reference MR image offline, (2) transferring V

comb
from the reference MR to a daily MR via DIR, (3) combining the transferred V

comb
with a region of high DIR inaccuracy, and (4) applying a threshold to the obtained final combined volume to generate the air volumes. The high DIR inaccuracy region was calculated from the absolute difference between the deformed daily and the reference images. This method was tested on 36 abdominal daily MRI sets acquired from 7 patients on a 1.5 T MR-Linac. The performance of DIFF was compared with alternative auto-air generation methods that (1) does not account for DIR inaccuracies, and (2) uses rigid registration instead of DIR. Main results. The results show that the proposed DIFF method can be fully automated and can be executed within 25 s. The Dice similarity coefficient of manual and DIFF auto-generated air contours was >92% for all cases, while it was 90% for the alternative auto-delineation methods. Dosimetrically, the auto-generated air regions using DIFF resulted in practically identical DVHs as those generated by using manual air contours. Significance. The DIFF method is robust and accurate and can be implemented to automatically consider the inter- and intra- fractional air volume variations during MRgOART for abdominal tumors. The use of DIFF method improves dosimetric accuracy as compared to other methods, especially beneficial for the patients with large daily abdominal air volume variations.
Self-supervised learning for multi-center magnetic resonance imaging harmonization without traveling phantoms
Authors: Chang Xiao , Cai Xin , Dan Yibo , Song Yang , Lu Qing , Yang Guang , Nie Shengdong 
Published: June 2022

Abstract

Objective. With the progress of artificial intelligence (AI) in magnetic resonance imaging (MRI), large-scale multi-center MRI datasets have a great influence on diagnosis accuracy and model performance. However, multi-center images are highly variable due to the variety of scanners or scanning parameters in use, which has a negative effect on the generality of AI-based diagnosis models. To address this problem, we propose a self-supervised harmonization (SSH) method. Approach. Mapping the style of images between centers allows harmonization without traveling phantoms to be formalized as an unpaired image-to-image translation problem between two domains. The mapping is a two-stage transform, consisting of a modified cycle generative adversarial network (cycleGAN) for style transfer and a histogram matching module for structure fidelity. The proposed algorithm is demonstrated using female pelvic MRI images from two 3 T systems and compared with three state-of-the-art methods and one conventional method. In the absence of traveling phantoms, we evaluate harmonization from three perspectives: image fidelity, ability to remove inter-center differences, and influence on the downstream model. Main results. The improved image sharpness and structure fidelity are observed using the proposed harmonization pipeline. It largely decreases the number of features with a significant difference between two systems (from 64 to 45, lower than dualGAN: 57, cycleGAN: 59, ComBat: 64, and CLAHE: 54). In the downstream cervical cancer classification, it yields an area under the receiver operating characteristic curve of 0.894 (higher than dualGAN: 0.828, cycleGAN: 0.812, ComBat: 0.685, and CLAHE: 0.770). Significance. Our SSH method yields superior generality of downstream cervical cancer classification models by significantly decreasing the difference in radiomics features, and it achieves greater image fidelity.
Two plasmon decay instability stimulated by large-incidence-angle laser in inertial confinement fusion
Authors: Lian C-W , Ji Y , Yan R , Cao S-H , Ren C , Wan Z-H , Yang D , Ding Y-K , Zheng J 
Published: June 2022

Abstract
The two-plasmon-decay instability (TPD) in the large-incidence-angle regime is studied via fluid and particle-in-cell (PIC) simulations. It is found that the TPD threshold in this regime within a narrow incidence angle range close to 60∘ can be orders of magnitude lower than the normal-incidence threshold. A threshold formula is proposed for this regime and is verified by fluid and PIC simulations. PIC simulations show significant laser absorption and energetic electron generation once TPD is excited. The incident angle and the laser spot size have a significant influence on the TPD in the large-incidence-angle regime. The low threshold and significant hot electron generation in this regime pose potentially unexpected preheating risks to inertial confinement fusion.
Magnetised and unmagnetized axisymmetric particle-in-cell simulations of ion energy distributions in cathodic vacuum arcs
Authors: Ryan Alexander , Bilek Marcela , Cairns Iver H , McKenzie David R 
Published: June 2022

Abstract
Cathodic arcs are electrical discharges consisting of a succession of discrete pulses of energetic plasma travelling from the surface of a cathode toward an anode. Currently, there are no vacuum arc simulations where spots are continuously generated with a set frequency, including the far-field plasma jet, with the inclusion of kinetic behaviour for both ions and electrons. The VSim 11 particle-in-cell software was used to simulate specific vacuum arcs as axisymmetric, electrostatic, and fully kinetic, from the initial generation of each cathode spot to the streaming plasma discharge at a far field, validating the predictions against experimental data. The models were configured to match the experimental arc gun of Zohrer et al and the Mevva V experiment with the cathode materials Al and Nb. The ion and electron velocity data were collected at the far edge of the simulation domain, analogous to a physical energy detector. The simulations successfully predicted the evolution of ion charge state energy distributions, showing peak unmagnetized ion energies that agree with prior experimental data, resulting in a mean error of 3% for Al and Nb. A peak in the electrostatic potential is observed above the cathode surface, supporting the potential hump theory as the cause of the higher-than-expected ion energies observed in cathodic arc discharges. Lower than expected relative energies between ion charge states are observed, matching prior experimental results, with this coupling of ion charge states attributed to non-stationary electrostatic wave–particle interactions, as the use of collisionless simulations rules out Coulombic ion friction. Magnetised simulations incorporated a statically powered short solenoid equivalent to the coil used in the Mevva V experiment to create a diverging magnetic nozzle. The magnetised simulation results demonstrate an annular jet of magnetically confined plasma and indicate an increase in nonstationary electrostatic effects including wave–particle interactions.
The Gamow shell model with realistic interactions: a theoretical framework for ab initio nuclear structure at drip-lines
Authors: Michel Nicolas , Li Jianguo , Xu Furong 
Published: June 2022

Abstract

Ab initio approaches are among the most advanced models to solve the nuclear many-body problem. In particular, the no-core–shell model and many-body perturbation theory have been recently extended to the Gamow shell model framework, where the harmonic oscillator basis is replaced by a basis bearing bound, resonance and scattering states, i.e. the Berggren basis. As continuum coupling is included at basis level and as configuration mixing takes care of inter-nucleon correlations, halo and resonance nuclei can be properly described with the Gamow shell model. The development of the no-core Gamow shell model and the introduction of the

Q

¯

ˆ

-box method in the Gamow shell model, as well as their first ab initio applications, will be reviewed in this paper. Peculiarities compared to models using harmonic oscillator bases will be shortly described. The current power and limitations of ab initio Gamow shell model will also be discussed, as well as its potential for future applications.
A Global Weizsäcker mass model with relativistic mean field shell correction*
Authors: Zhang W. , Li Z. Y. , Gao W. , Sun T. T. 
Published: June 2022

Abstract
A relativistic Weizsäcker mass model is proposed based on the single-particle levels and ground state deformations obtained in axial deformed relativistic mean field theory. The density functional of relativistic mean field theory is chosen as DD-LZ1, which can partially remove spurious shell closures. Compared with the fourth Weizsäcker-Skyrme mass model, the proposed model provides shell correction energies that exhibit wide spreading, and the root-mean-square mass deviation is 1.353 MeV. Further improvement is in progress.
Simulation of runaway electron production with CQL3D coupled to NIMROD
Authors: Petrov Yu.V. , Kim C.C. , Lao L.L. , Harvey R.W. 
Published: June 2022

Abstract
A coupling between two distinctly different codes—one magnetohydrodynamic (MHD) and another kinetic—is achieved and applied for simulation of runaway electron (RE) production. The 3D initial value MHD code NIMROD simulates a DIII-D pure neon shattered pellet injection plasma quench including the propagation and ablation of the fragments, ionization and recombination of the impurities, and the radiated and transported energies. The field data from NIMROD is then used by the bounce-averaged Fokker–Planck Collisional QuasiLinear 3D (CQL3D) kinetic code to simulate the production of REs and their radial transport. The coupling procedure involves mapping of data between different grids and adjustment of the NIMROD toroidal electric field when REs appear. It is shown that without the radial transport, a large RE current is generated, up to 30% of the pre-pellet ohmic current. However, when the radial transport is included in CQL3D, the RE current is reduced to undetectable level, consistent with experiment. Various forms of the radial diffusion are surveyed to determine conditions when the fast electrons would not have time to be accelerated to relativistic energies before they are lost to chamber wall.
A Learner-Centered Syllabus-Based Approach to engaging master students into research activity
Authors: Vlasenko K , Rovenska O , Lovianova I , Tarasenkova N , Achkan V 
Published: June 2022

Abstract
This paper presents a vision of a team of researchers on solving a problem of engaging future Mathematics teachers into a research activity through implementing person-centred approach to learning and teaching. The authors of the given article present a designed Learner-Centered Syllabus of a training research workshop in Mathematical Analysis for Master students, majoring in Mathematics at teacher training universities. This study presents the structure, the components and the content of a Learner-Centered Syllabus. When giving content to the sections of the syllabus, the developers take into consideration the conditions for person-centredness; creating the atmosphere of acceptance and congruence; shaping in students the personal qualities, which contribute to their research activity; arranging collaboration; engaging students into the assessment process. The researchers in the present study identify orientation at self-development as a key concept of the course policy and make each section of the syllabus personal. The following sets of attributes were used to evaluate the designed Learner-Centered Syllabus: Community, Power and Control, Assessment and Evaluation. The experimental study was done over four years, two groups of Master students majoring in Mathematics became its participants. One group was given a conventional Content-Focused Syllabus of a training research workshop in Mathematical Analysis, while the second group received a Learner-Centered Syllabus, designed in accordance with the Person-Centered Approach to Teaching and Learning. The analysis of the findings of this experiment justified the effciency of creating a learning environment, which is determined by the emotional components, such as Congruence, Acceptance and Empathic understanding. The present paper also shows a positive impact of the syllabus on the degree of students’ motivation to choose the training research workshop in Mathematical Analysis.
Geometric interpretation and visualization of particular geometric concepts at metric spaces study
Authors: Kuz’mich V I , Kuzmich L V , Savchenko A G , Valko K V 
Published: June 2022

Abstract
The paper considers the issues of studying method of geometric properties of metric spaces. These questions arise when students learn the basic concepts of the metric spaces theory. Difficulty in the concepts understanding arises due to the lack of the geometric interpretation or appropriate visualization. To build a geometric interpretation of rectilinear and flat placement of points of metric space, it is proposed to build the appropriate analogues in two-dimensional and three-dimensional arithmetic Euclidean spaces. To visualize these concepts, it is proposed to use a dynamic geometric environment GeoGebra 3D. This approach allows to demonstrate both the similarity of individual geometric concepts of metric space with the corresponding concepts of Euclidean geometry, and cases of the “non-Euclidean”. The study is useful for teachers and students of higher education institutions majoring in physics and mathematics. Some examples can be used in the study of basic geometric concepts by students of secondary education, in-depth study of mathematics and in various types of informal education.
Experience in the development and implementation of a system of visualized teaching cases in Physics using a digital computer measuring system Einstein
Authors: Yu Golovko N , Goncharenko T L , Korobova I V 
Published: June 2022

Abstract
Time has come to form a new education system. This is confirmed by the UNESCO initiative on the future of education for 2050 and thereafter and provides an opportunity to understand how education can shape the future of humanity and the planet. Today, the development of ICT, artificial intelligence, digital platforms and information growth are agents of change in the educational process. The amount of information in the world doubles every day; information-oriented society (a community connected to each other and the world through information and technology) is being formed. Open information systems, global educational networks, interacting digital resources, developing digital educational and information resources provide an opportunity to improve the quality of education. In view of this, special information educational resources are developed in accordance with the trends of science, regional context, individual characteristics and needs of students. In recent years, STEM education has been actively developing both in the world and in Ukraine. This contributes to students’ involvement into STEM disciplines, and young people’s choosing engineering professions. This article substantiates the feasibility of developing a system of visualized teaching cases in Physics. A classification of educational cases is proposed. The paper describes the experience of development and introduction of visualized cases using a combination of Google-services and digital computer measuring system Einstein in the process of teaching Physics as a STEM-discipline. The method of organization of classes with the help of digital computer measuring complex Einstein in the context of situational teaching of Physics is suggested. The article also presents the analysis of the results of implementation of the system of visualized Physics teaching cases into educational process on the basis of Physics and Educational Technologies Laboratory of Kherson State University.
Relationship between achievement in physics and mathematics and family functioning
Authors: Stojanović M. , Aksentijević T. 
Published: June 2022

AbstractThe development of pedagogical-psychological theories causes an increase in the number of examined factors (cognitive and non-cognitive). One of the non-cognitive factors is the family environment, so the paper deals with determining the connection between success in physics and mathematics and family functioning. In the research, 80 seventh and eighth-grade elementary school students participated. The constructed questionnaire included eight dimensions of family functioning: cohesion, flexibility, disunity, networking, chaos, rigidity, family communication, and family satisfaction. Results showed that students whose parents are married achieve significantly higher scores on all four mentioned scales. The children whose parents are divorced achieved the lowest marks. Also, the dimensions of communication and family satisfaction are rate as good. The chaotic component was influenced by parents‘ level of education, where the highest value was expressed by students whose parents are at the primary school level. This component proved to be important for students’ achievements in mathematics. Achievements in physics were influenced by the level of cohesion, whose increase also caused a higher student achievement. Family environment is an important factor determining students’ development, functioning, and school success, so it is important to monitor its impact and train teachers to work with students from dysfunctional families.
Systematic analysis of digital tools to provide STEM and science education
Authors: Shapovalov Ye B , Bilyk Z I , Usenko S A , Shapovalov V B 
Published: June 2022

AbstractRecently, attention is paid to conceptual aspects of STEM or particular usage of specific tools during STEM. This paper is devoted to systemize all digital tools used during STEM classes. It is proposed to systemize all equipment into instrumental, computer simulation, and modern ones (VR, AR, and AI and 3d-modelling). It is proved the dominant role of computer simulation and modern instruments during providing STEM classes due to their simplicity and absence of necessity of expensive equipment usage. Using any of the described tools do not guaranty providing STEM, but they can be used as an element of the STEM didactic approach.
A study of confinement induced surface structure of P3HT and P3HT/PCBM blend using grazing incidence diffraction
Authors: Kumar Manoj , Kumar Sunil , Singh Amarjeet 
Published: June 2022

Abstract
Thin films of P3HT and its blend with PCBM were investigated for vertical segregation of the crystalline structure using grazing incidence diffraction. The films were cast from a solution (P3HT/PCBM) on silicon substrates using the spin-coating technique, and their thickness (170–580 Å) were determined using x-ray reflectivity. In the grazing incidence diffraction technique, the scattered intensity is measured below and above the critical angle of incidence to distinguish the surface structure from the structure of the film underneath. We obtained a diffraction peak due to the lamellar alignment of P3HT perpendicular to the substrate. For thick films of pristine P3HT, the surface was more crystalline as compared to that of the entire film. In the blend films, the surface was found to be amorphous with crystalline structure underneath. The substrate interaction strongly influenced the crystal formation upon annealing at 110 °C as the structure of thicker films (∼600 Å) was strongly modified, whereas that of thinner films (170–290 Å) was negligibly affected.
Field deployable atomics package for an optical lattice clock
Authors: Kale Yogeshwar B , Singh Alok , Gellesch Markus , Jones Jonathan M , Morris David , Aldous Matthew , Bongs Kai , Singh Yeshpal 
Published: June 2022

Abstract
An atomics package is the heart of any atom based quantum sensing device. Here we report on the realisation of a field deployable atomics package for alkaline earth atoms, e.g. Sr or Yb. In terms of size (∼121 L), weight (<75 kg) and power (∼320 W), it is the smallest package to date which is designed to load Sr atoms into an optical lattice. It consists of an ultra-high vacuum assembly (<4 L), lasers, magnetic field coils & optics required for cooling & trapping as well as a module for imaging & detection. The package can routinely produce ultra cold and dense samples of 1.6 × 105
88Sr atoms trapped in a 1D optical lattice in less than a second. Its robustness has been demonstrated by conducting two transportation campaigns within out-of-the-lab environments. This advancement will have impact not only on transportable optical clock development but also will influence the wider areas of quantum science and technologies, particularly requiring field deployable cold atom based quantum sensors.