bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shape dependent multiferroic behavior in Bi2Fe4O9 nanoparticles
Authors: Sahoo Aditi , Bhattacharya Dipten , Das Moumita , Mandal Prabhat 
Published: April 2022

Abstract
Ferroelectric and magnetic properties are investigated for Bi2Fe4O9 nanoparticles with different shapes (cuboid and sphere-like) synthesized by hydrothermal and sol-gel method. The magnetic study reveals that coercivity, Neel temperature and remanent magnetization strongly depend on shape of the particle. The nanoparticle with sphere-like shape exhibits magnetization curve of antiferromagnetic (AFM) ordering with ferromagnetic (FM) component. As the particle shape changes from sphere-like to cuboid, the AFM component is dominating over the ferromagnetic component. A small exchange bias is also observed at low temperature in both the sphere-like and cuboid nanoparticle. The coercivity, remanent magnetization and Neel temperature of sphere-like nanoparticle is greater than cuboid nanoparticle. Ferroelectric measurement shows the remanent polarization of cuboid is greater than sphere-like nanoparticle but the coercivity is almost same. This Bi2Fe4O9 nanoparticle shows a small change in polarization under magnetic field. The polarization value decreases with magnetic field increases. The magnetoelectric coupling-measured by change of remanent polarization under magnetic field are found to be greater in Bi2Fe4O9 sphere-like nanoparticles. These shape dependent magnetic and ferroelectric properties are coming because of shape anisotropy.
‘Astrophysics: history and theory’, an undergraduate, interdisciplinary, asynchronous astrophysics course taught in the physics program
Authors: Trout Joseph J , Jacobsen Tara , Buondonno Gracie , Weber Courtney 
Published: April 2022

Abstract
This project produced an online astronomy course based on the free, online OpenStax textbook. When this project was conceived, about a year before the Covid-19 pandemic, the authors had no idea that in a short period of time, most college and university classes would be online. This abrupt change in modalities of courses, from traditional, face-to-face lectures and laboratories to a more modern online format, sparked energetic discussions about the effectiveness of online courses. This paper describes the online astronomy course and its creation and evaluates the success of the course at conveying the concepts and theories studied in astronomy courses. The success of this course is examined using a 100-question pre-test and post-test based on content knowledge. A survey was also completed of the students to evaluate the perceived success of the online course and the acceptance of online courses. The survey was adjusted to include opinions about the in-person labs that were cancelled due to the Covid-19 pandemic.
Simple motor variants
Authors: Lee Heejin , Chen Yu , Lee Jiwon , Moon Su Jin , Kim Jung Bog 
Published: April 2022

Abstract
We have developed new rotors that can be classified into three groups by changing the rotors used in simple motors into various types. Group I has a semicircular shape rather than a perfect circle or square shape, group II has a structure consisting of several closed circles on one plane, and group III has a three-dimensional shape. We wanted to show students that a closed circular shape is not the only thing that can rotate in a magnetic field, and that various types of rotors are possible. Also, we think it would be good to give students an opportunity to envision different shapes of rotors.
An accelerator experiment for junior and senior high school students to improve students’ involvement in fundamental physics
Authors: Tanaka K S , Harada K , Hayamizu T , Kita R , Kono R , Maruta K , Nagahama H , Ozawa N , Sakemi Y , Sugimori R 
Published: April 2022

Abstract
In Japan, research activities by junior and senior high school students show an upward trend. However, there are limited examples of research activities in the field of elementary particles and atoms. This is due to the difficulty associated with procuring research tools such as accelerators or particle detectors. Therefore, we hosted the ‘Accel Kitchen’ in 2018 and 2019 at the Cyclotron and Radioisotope Center (CYRIC) in Tohoku University where junior and senior high school students could participate in ongoing research of particle and atomic physics. At each workshop, 12 junior and senior high school students participated in the beam experiment, including the production of francium atoms (Fr) by the fusion reaction of oxygen and gold, optimizing the transport of the ion beam and identifying the alpha decay nuclei, and laser trapping of Fr for two days. Each group that was involved in the experiment was supported by researchers and university students who acted as mentors. This was the first opportunity for junior and senior high school students to know about the particle beam experiment in Japan.
On the merits of a unified physics and engineering undergraduate programme of study
Authors: Nezhad Maziar P 
Published: April 2022

Abstract
The merits of a pedagogic and programmatic unification between physics and several engineering disciplines at the undergraduate level are discussed. Arguments for such a unification are presented, based on the strong overlap of core teaching material and the similarity of career trajectories in the modern job market for physics and engineering graduates. In addition to providing a level of robustness for academic institutions against external factors such as fluctuating student intake numbers, such a merger can also have positive dividends for increased inclusion of minority and female students in STEM fields. The widespread availability and affordability of advanced laboratory equipment, computing hardware/software and other technical infrastructure at the current time is also highlighted as a reason for the practical feasibility of this approach.
Microcontroller based study of diode thermometers for online demonstration of undergraduate laboratory classes in COVID-19 lockdown
Authors: Biswas Subhrajyoti , Roy Durjoy 
Published: April 2022

Abstract
At constant current (I) the forward bias potential (V) of a pn junction diode may be considered to vary linearly with temperature (t) within a temperature range. Based on this property we have constructed diode thermometer using germanium (Ge) and silicon (Si) diodes. The experimental

V

−

t

data at constant forward current have been fitted to a straight line for calibration of the diode thermometers using the least square method. Furthermore, the fitting parameters of the straight line have also been used to determine the band gap energy of germanium and silicon and experimental values of band gap for both the semiconductor materials are found to agree well with accepted values.
The little robot, black holes, and spaghettification
Authors: Pinochet Jorge 
Published: April 2022

Abstract
The tidal forces generated by a black hole can be so powerful that they cause unlimited stretching, known as spaghettification. A detailed analysis of this phenomenon requires the use of Einstein’s theory of general relativity. The aim of this paper is to offer an up-to-date and accessible analysis of spaghettification, in which the complex mathematics of Einstein’s theory are replaced with the simpler and more intuitive concepts of Newtonian gravity. The article can serve as educational material for undergraduate modern physics or astronomy courses.
Magnetic levitator fitted with the Hall sensor readings
Authors: Zvorykin Ilya Yu , Katkova Mariia R , Maslennikova Yulia V 
Published: April 2022

Abstract
In this article, we propose a simple and accessible model of a magnetic levitator fitted with a Hall sensor. This model also allows to determine the magnitude of the magnetic field within the levitator working volume. Students can also compare the experimental magnetic field values to reference values in magnetism textbooks. This Arduino-based levitator may be built by a student under teacher’s supervision as part of an individual project in high school or secondary school setting.
A teaching proposal for the didactics of Special Relativity: the spacetime globe
Authors: Leonardi Alessio Mattia , Mobilio Settimio , Fazio Claudio 
Published: April 2022

Abstract
Special Relativity introduces students to Modern Physics, whose importance in the high school is increasing. Nevertheless its teaching and learning is a critical issue. Different solutions have been developed to overcome the encountered difficulties. In this paper we describe the spacetime globe, a mechanical instrument that allows to experience Special Relativity hands-on. We show how it is possible to treat all the main phenomena foreseen by Special Relativity with simple laboratory experiences, using the idea of Minkowski’s spacetime diagrams. The aim is to develop the use of geometrical approach in learning Special Relativity in high schools.
On the operation of the Hanstead car
Authors: Persson Rasmus A X 
Published: April 2022

Abstract
We consider the operation of the hypothetical mechanical vehicle driven by an engine powered by small rockets introduced by P D Hanstead in the inaugural volume of this journal. Hanstead arrived at three contradictory conclusions regarding the change in velocity should some of the rockets malfunction at a particular time. This thought experiment constitutes an excellent, conceptual discussion, or even exam, question for an introductory mechanics course.
Building a digital barometer with Arduino to study forces due to atmospheric pressure and weather maps at schools
Authors: Moya Antonio Ángel , Merino Ana 
Published: April 2022

Abstract
We describe a simple STEM project for students to learn to measure atmospheric pressure by using a sensor of the type BMP180 together with the Arduino electronic platform. The collected experimental data, together with simple experiments, can be used to study the different pressure units and the relationship between pressure and force. Also, they can be used to study basic meteorology concepts associated with the movement of air on isobar maps, and to include transversal competences related to environmental education.
Limits of the simple pendulum formula for classroom use
Authors: Oliveira Vitor 
Published: April 2022

Abstract
We discuss the limits of the equation of the period of a simple pendulum,

T
s

=
2
π

l

/

g

, frequently used in high-school and university classrooms to measure the acceleration of gravity. We evaluate the relative error in determining the acceleration of gravity with this simple equation instead of a more realistic one, taking into account the string’s mass, the bob’s radius, and finite angular displacements. We show that the bob radius and finite angular displacements increase the period of oscillation of the pendulum and, hence, contribute to a positive deviation in the value of g calculated with the simple pendulum formula. On the other hand, the string’s mass decreases the pendulum’s period and induces a negative deviation in the value of g. As a result, it is possible to adapt the pendulum’s characteristics to use the simple pendulum formula and calculate g with accuracy.
Experimental characterisation of the magnetic field correction factor,

kB⃗,

for Roos chambers in a parallel MRI-linac
Authors: Begg Jarrad , Jelen Urszula , Keall Paul , Liney Gary , Holloway Lois 
Published: April 2022

Abstract

Objective. Reference dosimetry on an MRI-linac requires a chamber specific magnetic field correction factor,

k

B
⃗

.

This work aims to measure the correction factor for a parallel plate chamber on a parallel MRI-linac. Approach.

k

B
⃗

is defined as the ratio of the absorbed dose to water calibration coefficient in the presence of the magnetic field,

N

D
,
w

B
⃗

relative to that under 0 T conditions,

N

D
,
w

0
T

.

k

B
⃗

was measured via a

N

D
,
w

transfer to a field chamber at each magnetic field strength from a chamber with known

N

D
,
w

and

k

B
⃗

.

This was achieved on the parallel MRI-linac by moving the measurement set-up between a high magnetic field strength region at the MRI-isocentre and a low magnetic field strength region at the end of the bore whilst maintaining consistent set-up and scatter conditions. Three PTW 34001 Roos chambers were investigated as well as a PTW 30013 Farmer used to validate methodology. Main Results. The beam quality used for the measurements of

k

B
⃗

was TPR
20/10 = 0.632. The

k

B
⃗

for the PTW Farmer chamber at 1 T on a parallel MRI-linac was 0.993 ± 0.013 (k = 1). The average

k

B
⃗

factor measured for the three Roos chambers on a 1 T parallel MRI-linac was 0.999 ± 0.014 (k = 1). Significance. The results presented are the first measurements of

k

B
⃗

for a Roos chamber on a parallel MRI-linac. The Roos chamber results demonstrate the potential for the chamber as a reference dosimeter in parallel MRI-linacs.
Predict alone, decide together: cardiac abnormality detection based on single lead classifier voting
Authors: Aublin Pierre G , Ben Ammar Mouin , Fix Jeremy , Barret Michel , Behar Joachim A , Oster Julien 
Published: April 2022

Abstract

Objective. A classifier based on weighted voting of multiple single-lead based models combining deep learning (DL) representation and hand-crafted features was developed to classify 26 cardiac abnormalities from different lead subsets of short-term electrocardiograms (ECG). Approach. A two-stage method was proposed for the multilead prediction. First a lead-agnostic hybrid classifier was trained to predict the pathologies from single-lead ECG signals. The classifier combined fully automated DL features extracted through a convolutional neural network with hand-crafted features through a fully connected layer. Second, a voting of the single-lead based predictions was performed. For the 12-lead subset, voting consisted in an optimised weighting of the output probabilities of all available single lead predictions. For other lead subsets, voting simply consisted in the average of the lead predictions. Main results. This approach achieved a challenge test score of 0.48, 0.47, 0.46, 0.46, 0.45 on the 12, 6, 4, 3, 2-lead subsets respectively on the 2021 Physionet/Computing in Cardiology challenge hidden test set. The use of an hybrid approach and more advanced voting layer improved some individual class classification but did not offer better generalization than our baseline fully DL approach. Significance. The proposed approach showed potential at correctly classifying main cardiac abnormalities and dealt well with reduced lead subsets.
Towards a fusion power plant: integration of physics and technology
Authors: Morris A W , Akers R J , Cox M , Militello F , Surrey E , Waldon C W , Wilson H R , Zohm H 
Published: April 2022

Abstract
A fusion power plant can only exist with physics and technology acting in synchrony, over space (angstroms to tens of metres) and time (femtoseconds to decades). Recent experience with the European DEMO programme has shown how important it is to start integration early, yet go deep enough to uncover the integration impact, favourable and unfavourable, of the detailed physical and technological characteristics. There are some initially surprising interactions, for example, the fusion power density links the properties of materials in the components to the approaches to waste and remote maintenance in the context of a rigorous safety and environment regime. In this brief tour of a power plant based on a tokamak we outline the major interfaces between plasma physics and technology and engineering considering examples from the European DEMO (exhaust power handling, tritium management and plasma scenarios) with an eye on other concepts. We see how attempting integrated solutions can lead to discoveries and ways to ease interfaces despite the deep coupling of the many aspects of a tokamak plant. A power plant’s plasma, materials and components will be in new parameter spaces with new mechanisms and combinations; the design will therefore be based to a significant extent on sophisticated physics and engineering models making substantial extrapolations. There are however gaps in understanding as well as data—together these are termed ‘uncertainties’. Early integration in depth therefore represents a conceptual, intellectual and practical challenge, a challenge sharpened by the time pressure imposed by the global need for low carbon energy supplies such as fusion. There is an opportunity (and need) to use emerging transformational advances in computational algorithms and hardware to integrate and advance, despite the ‘uncertainties’ and limited experimental data. We use examples to explore how an integrated approach has the potential to lead to consistent designs that could also be resilient to the residual uncertainties. The paper may stimulate some new thinking as fusion moves to the design of complete power plants alongside an evolving and maturing research programme.
Plasma power balance: methodology and investigations of microwave capillary discharges
Authors: Coquery F , Leroy O , Minea T , Stancu G D 
Published: April 2022

Abstract
Nowadays, where strong energy constraints are set by the environmental and economical context, the real power coupled in plasmas becomes a critical aspect particularly for applications where plasma technologies are facing competition. This issue is enhanced for atmospheric pressures micro-plasmas, where the local power density can be very high (e.g. 105 W cm−3) which implies fast heat exchanges. The precise knowledge of the power coupled to plasma is also a key for fundamental understanding of discharge properties. This is often used as an input parameter for plasma modeling and its inaccuracy can mitigate the predictive quality of plasma simulation tools. In the present paper the macroscopic power balance was established for continuous microwave (MW) plasmas generated in capillaries in argon gas flows. The macroscopic power budgets were performed based on measurements of microwave leak fluxes, heat fluxes (thermal radiation, convection, conduction), optical radiation and chemical powers. It was proven that the traditional power measurements at the MW generator would largely overestimate the real power coupled to plasmas, namely by at least a factor two. An important power fraction is found in the heat transfer through the MW launcher, the impedance mismatching being here better assessed. The proposed methodology, which is based on the physics of transport phenomena, can be employed for characterization of other (micro-) plasma sources.
The muon Smasher’s guide
Authors: Al Ali Hind , Arkani-Hamed Nima , Banta Ian , Benevedes Sean , Buttazzo Dario , Cai Tianji , Cheng Junyi , Cohen Timothy , Craig Nathaniel , Ekhterachian Majid , Fan JiJi , Forslund Matthew , Garcia Isabel Garcia , Homiller Samuel , Koren Seth , Koszegi Giacomo , Liu Zhen , Lu Qianshu , Lyu Kun-Feng , Mariotti Alberto , McCune Amara , Meade Patrick , Ojalvo Isobel , Oktem Umut , Redigolo Diego , Reece Matthew , Sala Filippo , Sundrum Raman , Sutherland Dave , Tesi Andrea , Trott Timothy , Tully Chris , Wang Lian-Tao , Wang Menghang 
Published: April 2022

Abstract
We lay out a comprehensive physics case for a future high-energy muon collider, exploring a range of collision energies (from 1 to 100 TeV) and luminosities. We highlight the advantages of such a collider over proposed alternatives. We show how one can leverage both the point-like nature of the muons themselves as well as the cloud of electroweak radiation that surrounds the beam to blur the dichotomy between energy and precision in the search for new physics. The physics case is buttressed by a range of studies with applications to electroweak symmetry breaking, dark matter, and the naturalness of the weak scale. Furthermore, we make sharp connections with complementary experiments that are probing new physics effects using electric dipole moments, flavor violation, and gravitational waves. An extensive appendix provides cross section predictions as a function of the center-of-mass energy for many canonical simplified models.
Influence of fabrication parameters on the magnetic and structural properties of Mn5Ge3
Authors: Xie Yufang , Li Zichao , Begeza Viktor , Funk Hannes Simon , Fischer Inga Anita , Zeng Yu-Jia , Helm Manfred , Zhou Shengqiang , Prucnal Slawomir 
Published: April 2022

Abstract
Mn5Ge3 is a ferromagnetic material with the high potential for spintronic applications. Usually, it is grown by conventional solid state reaction of manganese with germanium using molecular beam epitaxy. Here, we report the structural and magnetic properties of Mn5Ge3 layers grown on Ge substrates using ultrafast-solid phase epitaxy (SPE) method. We investigate the influence of the substrate orientation, Mn layer thickness and annealing parameters on the crystallographic orientation and magnetization of Mn5Ge3. It is shown that after millisecond range SPE, Mn5Ge3 films always have a preferred (100) orientation whether grown on Ge (001) or (111) substrates, which determines the orientation of the magnetization easy axis lying in the film plane along c axis independent of the layer thickness. The Curie temperature of Mn5Ge3 weakly depends on fabrication parameters.
Single event burnout sensitivity of SiC and Si
Authors: Littlefair Matthew T M , Simdyankin Sergei , Turvey Simon , Groves Chris , Horsfall Alton B 
Published: April 2022

Abstract
Exposure to ionizing radiation has the potential to catastrophically modify the operation, and destroy, electronic components in microseconds. The electrification of aircraft necessitates the need to use the most power dense and lowest loss semiconductor devices available, and the increasing supply voltages results in extremely high electric fields within the devices. These conditions create the worst case environment for the Single Event Effect (SEE), the instantaneous alteration in device response after high energy particle interaction, with a destructive form of SEE, the single event burnout (SEB), resulting in total failure of the device with potentially explosive consequences. To enable circuits to operate with these high supply voltages, SiC is rapidly becoming the semiconductor of choice. However, the radiation response of SiC power devices during operation is unknown. Here we show that SiC offers a 60% reduction in cosmic ray sensitivity in comparison to Si devices with an equivalent voltage rating. The data show that Si fails when subjected to a heavy ion impact with Linear Energy Transfer (LET) equivalent to 0.2% of the silver ions commonly used for SEE testing. In total contrast, we show that SiC does not exhibit failure during exposure to any heavy ion LET up to values three times greater than those commonly used in testing at any bias up to 99% of the breakdown voltage. The data show that SiC is a robust material and therefore has the potential to replace Si as the material of choice for high reliability avionic applications, as it far exceeds the performance of Si in cosmic ray environments, facilitating significant advances in the electrification of aircraft to be made in the near future.