bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pacing and packing behaviour in elite and world record performances at Berlin marathon
Authors: Muñoz‐Pérez Iker , Lago‐Fuentes Carlos , Mecías‐Calvo Marcos , Casado Arturo 
Published: August 2022

ABSTRACTThe aim of this study was to compare pacing and packing behaviours between sex and performance level at elite Berlin marathon races. Official electronic split and finishing times from 279 (149 male and 130 female) marathon performances, including 5 male world records, were obtained from 11 Berlin marathon races held from 2008 to 2018, and from two previous world records and the second world all‐time fastest performance also achieved at that same Berlin course. Male performances displaying an even pacing behaviour were significantly faster than those adopting a positive behaviour (p < 0.001; d = 0.75). Male world records were characterized by even profiles with fast endspurts, being especially remarkable at world all‐time two fastest performances which were assisted by the use of a new shoe technology. Female marathon runners decreased their speed less than men during the second half marathon and especially from the 35th km onwards (p < 0.001; 0.51 ≤ d ≤ 0.55). The latest race stages were usually run individually in both sexes. Significant pace differences between performance groups at every race segment were found in women (p < 0.01; 1.0 ≤ d ≤ 2.0), who also covered an important part of the race alone. Prior to participation in meet marathon races such as Berlin marathon, elite runners should select the group that they will join during the race according to their current performance level as a preassigned pace set by a pacemaker will be adopted. Therefore, they could follow an even rather than positive pacing behaviour which will allow them to achieve a more optimal performance.
Multi-level images around Kerr–Newman black holes
Authors: Hou Yehui , Liu Peng , Guo Minyong , Yan Haopeng , Chen Bin 
Published: August 2022

Abstract
We study the lensing effects of Kerr–Newman (KN) black holes and the multi-level images of luminous sources around the black holes. We obtain the analytic forms of the lens equations in KN spacetime and derive approximately their limiting forms for photon emissions near the bounded photon orbits. After deriving the expressions of three key parameters γ, δ and τ, we investigate the primary, the secondary and the higher-order images of spherical sources and equatorial disk-like sources. In particular, we find that the charge of KN black hole has a significant effect on the higher-order images.
A brief review on the spin valve magnetic tunnel junction composed of 2D materials
Authors: Elahi Ehsan , Dastgeer Ghulam , Sharma Pradeep Raj , Nisar Sobia , Suleman Muhammad , Iqbal Muhammad Waqas , Imran Muhammad , Aslam Muhammad , Imran Ali 
Published: August 2022

Abstract
Two-dimensional (2D) materials including graphene, hexagonal boron nitride, and transition metal dichalcogenides have revolutionized electronic, optoelectronic and spintronic devices. Recent progress has been made in the knowledge of spin injection, detection, and manipulation utilizing spintronic devices based on 2D materials. However, some bottlenecks still need to be addressed to employ spintronic devices for logical applications. Here, we review the major advances and progress in vertical magnetic tunnel junctions (MTJs) made of various 2D materials as spacer layers between distinct ferromagnetic electrodes. Spin transportation characteristics depending on the magnetic field are investigated by considering the magnetoresistance (MR) and tunneling MR ratio in vertically stacked structures. This review examines the important features of spin transfer through the various spacer 2D materials in MTJs by carefully analyzing the temperature-dependent phenomena. The underlying physics, reliance of spin signals on temperature, quality of junction, and various other parameters are discussed in detail. Furthermore, newly discovered 2D ferromagnets introduce an entirely new type of van der Waals junction enabling effective dynamic control and spin transport across such heterojunctions. Finally, the challenges and prospects of 2D materials-based spin-valve MTJs for improving spintronic devices are discussed in detail.
Generated four-wave mixing in temperature controlled mixtures of carbon disulfide and benzene
Authors: Li Shuang , Liang Han , Liu Xiaofeng , Fang Wenhui , Sun Chenglin , Men Zhiwei 
Published: August 2022

Abstract
Generated four-wave mixing (FWM) from the Cascaded stimulated Raman scattering (SRS) process of the mixtures of carbon disulfide and benzene on temperature was investigated. At the low temperature conditions, the stimulated Brillouin scattering can be significantly suppressed, the beam distortion caused by thermal self-defocusing effect can be reduced, thereby improving the energy conversion efficiency of SRS. Not only the multi-order Stokes and anti-Stokes SRS of CS stretching vibration, CC ring skeleton vibration and CH stretching vibration were obtained, but also the 1st (∼583 nm) and 2nd -order (∼646 nm) FWM was generated by the Stokes light, anti-Stokes light and pump laser. At 20 °C, the highest conversion efficiency is 32%, and the peak intensity of FWM is also the intensest. The results are of great significance for the multi-wavelength Raman laser in liquid medium.
A review of metal–semiconductor contacts for β-Ga2O3
Authors: Lu Chao , Ji Xueqiang , Liu Zeng , Yan Xu , Lu Nianpeng , Li Peigang , Tang Weihua 
Published: August 2022

Abstract

β-Gallium oxide (β-Ga2O3) has been studied extensively in recent decades due to its excellent usability in fabricating a variety of devices, such as solar-blind photodetectors and power devices. However, as an important part of a device, related investigations of β-Ga2O3–metal contacts, especially for Schottky contacts, are rare. In this review, we summarize recent research progress on β-Ga2O3–metal contacts, including related theories, measurements, fabrication processes, control methods, etc. This review will provide insights for both theoretical understanding of the metal/semiconductor interface, as well as the fabrication process for engineering applications of Ga2O3-based devices.
The nature of excitons in PPDT2FBT:PCBM solar cells: Role played by PCBM
Authors: Sahoo Subhamoy , Barah Dhruvajyoti , Kumar S Dinesh , Xavier Nithin , Dutta Soumya , Ray Debdutta , Bhattacharyya Jayeeta 
Published: August 2022

Abstract
In organic semiconductor-based bulk heterojunction solar cells, the presence of an acceptor increases the formation of charge-transfer (CT) excitons, thereby leading to higher exciton dissociation probabilities. In this work we used steady-state electroabsorption (EA) measurements to probe the change in the nature of excitons as the blend composition of the solar cell active layer material was varied. We investigated blends of poly[(2,5-bis(2-hexyldecyloxy)phenylene)-alt-(5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c]-[1,2,5]thiadiazole)] (PPDT2FBT) and (6,6)-phenyl C71 butyric acid methyl ester (PCBM). Analysis of the EA spectra showed that in the presence of a fullerene-based acceptor, like PCBM, CT characteristics of the excitons were modified, though no new CT signature was observed in the blend. Enhancement in the CT characteristics in the blend was reflected in photoluminescence (PL) measurements of the blends, where PL quenching of ∼63% was observed for 1% PCBM. The quenching reaches saturation at about 20% PCBM. However, efficiency of the device increased with a PCBM percentage beyond 20%. Maximum efficiency was obtained for the blend with 50% PCBM, among the blend compositions studied in this work, indicating the optimum concentration of PCBM for best power conversion efficiency to be around that value. When we compared the experimental results with simulations, the variation of the device efficiency with PCBM percentage was shown to arise from multiple factors, such as an increase in the polarizability and dipole moment of excitons, and the efficiency of the carrier collection from the bulk of the active layer.
Sustainable carbon coated ZrO2 electrodes with high capacitance retention for energy storage devices
Authors: Singh Nirbhay , Tanwar Shweta , Kour Simran , Sharma A L , Yadav B C 
Published: August 2022

Abstract
The rapid development of modern technology starves for future research to attain high-energy, high-power, and high cyclic stable energy-storage devices. Carbonaceous electrodes in supercapacitors provide a large-power device, which stores the charge between the surface of the carbonaceous electrode and the electrolyte layer. The commercially available electrode based on pure carbon suffers from low energy density. To overcome the mentioned issue, major efforts have been dedicated to enhancing the charge storage of carbonaceous electrodes by the addition of both pure capacitive material (such as Carbon and its derivative) and pure battery-type material (transition-metal oxide, hydroxides, etc). Mesoporous carbon due to its advanced feature along with ZrO2 good fit on performance and environmental aspect parameters. In this report, we have prepared environmentally friendly mesoporous carbon ZrO2 composite by the facile method, initially, ZrO2 is prepared hydrothermally after that mixing is done at room temperature to obtain the final product mesoporous carbon@ZrO2. The material structural, and microstructural examinations are done by x-ray diffraction analysis, and field emission scanning electron microscopy. The galvanostatic charging-discharging (GCD) analysis shows the specific capacitance of the device is 125 F g−1 and the energy density of the device is 25 Wh kg−1 at a current density of 0.5 A g−1. The GCD shows an extreme power density of 1201 W kg−1 at 1 mA. The cyclic voltammetry analysis shows the maximum specific capacitance of 54.5 F g−1 at 10 mV s−1. The long-term cyclic stability of up to 10 000 cycles is tested through GCD. The device shows high capacitance retention and Coulombic efficiency till the last GCD cycle at 82% and 100% respectively. The capacitive contribution is 55% for optimized electrodes. The prototype device formation and load light emitting diode (LED) testing are done at the laboratory. Based on experimental findings we have proposed a charge storage mechanism for a better understanding of readers.
Radiation exposure to extremities in medical applications and its implications for the radiation protection of workers in the Philippines
Authors: Romallosa Dean Kristine Marie , Panlaqui Angelo , Betos Christy Mae , Acha Jericissa Amberrose 
Published: August 2022

Abstract
In medical applications, non-homogeneous radiation exposure conditions may be encountered and whole-body monitoring alone may not be an adequate assessment of doses received by workers. This paper investigated the exposure to extremities in medical applications in the Philippines in terms of personal dose equivalent Hp(0.07). Profiles of monitored workers, dose levels, implications on optimization of occupational exposures, and factors affecting the extremity monitoring implementation were studied. The results show that <3% of workers are monitored for extremities, and there is no monitoring of eye lens dose. There is no extremity monitoring in diagnostic radiology, particularly interventional radiology. Dose levels to extremities were higher and more varied than whole-body doses. In nuclear medicine, the median annual extremity dose is 1.2 mSv, the interquartile range (IQR) is 7.6 mSv (Q1 = 0.5 mSv, Q3 = 8.1 mSv), and the maximum dose is 35 mSv. These median and IQR dose values are four and eight times higher, respectively, compared to the whole-body dose. In radiopharmaceutical distribution, the extremity median annual dose is five times higher than the whole-body dose, and the IQR value is 12 times higher where IQR is 12.1 mSv (Q1 = 0.1 mSv, Q3 = 12.2 mSv). Most notable is in cyclotron operations where <40% of workers were monitored on their extremities; however, the median dose is 100 times higher than the whole-body dose, with a maximum dose of 148 mSv. The results imply that there may be an underassessment of occupational exposure of workers in medical applications. As monitoring results are used for the establishment of a radiation protection program, lack of consideration of extremity doses can lead to inadequate measures in the optimization of worker protection. This study thus shows the need to enhance the implementation of extremity and eye lens dose monitoring in the Philippines to further strengthen the radiation protection of workers in medical applications.
In situ off-axis electron holography of real-time dopant diffusion in GaAs nanowires
Authors: Balasubramanian Ganapathi Prabhu Sai , Lebedkina Elizaveta , Goktas Nebile Isik , Wagner Jakob Birkedal , Hansen Ole , LaPierre Ray , Semenova Elizaveta , Mølhave Kristian , Beleggia Marco , Fiordaliso Elisabetta Maria 
Published: August 2022

Abstract
Off-axis electron holography was used to reveal remote doping in GaAs nanowires occurring during in situ annealing in a transmission electron microscope. Dynamic changes to the electrostatic potential caused by carbon dopant diffusion upon annealing were measured across GaAs nanowires with radial p-p+ core–shell junctions. Electrostatic potential profiles were extracted from holographic phase maps and built-in potentials (Vbi
) and depletion layer widths (DLWs) were estimated as function of temperature over 300–873 K. Simulations in absence of remote doping predict a significant increase of Vbi
and DLWs with temperature. In contrast, we measured experimentally a nearly constant Vbi
and a weak increase of DLWs. Moreover, we observed the appearance of a depression in the potential profile of the core upon annealing. We attribute these deviations from the predicted behavior to carbon diffusion from the shell to the core through the nanowire sidewalls, i.e. to remote doping, becoming significant at 673 K. The DLW in the p and p+ regions are in the 10–30 nm range.
Designing boron-cluster-centered zwitterionic Y-shaped clocked QCA molecules
Authors: Liza Nishattasnim , Lu Yuhui , Blair Enrique P 
Published: August 2022

Abstract
Quantum-dot cellular automata (QCA) is a nanoscale, transistor-less device technology. A single molecule may provide an elementary QCA device known as a cell. Molecular redox centers function as quantum dots, and the configuration of mobile charge on the dots encodes device states useful for classical computing. Molecular QCA may support ultra-high device densities and THz-scale switching speeds at room temperature. An applied electric field may be used to clock molecular QCA, providing power gain to boost weakened signals, as well as quasi-adiabatic device operation for minimal power dissipation in QCA devices and circuits. A zwitterionic, Y-shaped, three-dot molecule may function as a field-clocked QCA cell. We focus on the design of a counterion built into the center of the cell. Ab initio computations demonstrate that choice of counterion determines the number of mobile charges for encoding the device state on the three quantum dots. We use

B

5

H

5

2
−

or

B

4

CH

5

−

as the central counterionic linker for two different Y-shaped, three-dot QCA molecules. While both molecules support the desired device states, the number of trapped charges in the counterion determines the number of mobile holes on the molecular quantum dots. This, in turn, determines whether the device state is encoded by a hole or an electron. This choice of encoding determines how the molecular QCA cell responds to a clocking field. The two counterions studied here lead to two QCA molecules with opposite responses to the clock, similar to the complementary responses of PMOS and NMOS transistors to gated voltage control.
Large-area vertically aligned 2D MoS2 layers on TEMPO-cellulose nanofibers for biodegradable transient gas sensors
Authors: Yoo Changhyeon , Yoon Jaesik , Kaium Md Golam , Osorto Brandon , Han Sang Sub , Kim Jung Han , Kim Bo Kyoung , Chung Hee-Suk , Kim Dong-Joo , Jung Yeonwoong 
Published: August 2022

Abstract
Crystallographically anisotropic two-dimensional (2D) molybdenum disulfide (MoS2) with vertically aligned (VA) layers is attractive for electrochemical sensing owing to its surface-enriched dangling bonds coupled with extremely large mechanical deformability. In this study, we explored VA-2D MoS2 layers integrated on cellulose nanofibers (CNFs) for detecting various volatile organic compound gases. Sensor devices employing VA-2D MoS2/CNFs exhibited excellent sensitivities for the tested gases of ethanol, methanol, ammonia, and acetone; e.g. a high response rate up to 83.39% for 100 ppm ethanol, significantly outperforming previously reported sensors employing horizontally aligned 2D MoS2 layers. Furthermore, VA-2D MoS2/CNFs were identified to be completely dissolvable in buffer solutions such as phosphate-buffered saline solution and baking soda buffer solution without releasing toxic chemicals. This unusual combination of high sensitivity and excellent biodegradability inherent to VA-2D MoS2/CNFs offers unprecedented opportunities for exploring mechanically reconfigurable sensor technologies with bio-compatible transient characteristics.
Janus Ga2SSe nanotubes as efficient photocatalyst for overall water splitting
Authors: Li Lijian , Zhao Chen , Zhang Yujiao , Zhang Long , Zhu Yingtao 
Published: August 2022

Abstract
Using sunlight to decompose water into hydrogen and oxygen is one of the most important ways to solve the current global environmental issues and energy problems. In this paper, we use density functional theory to predict the photocatalytic performance of Janus Ga2SSe nanotubes (JGSSe NTs) for the first time. The result shows that the small formation energy and strain energy ensure the stability of the nanotubes. Compared with monolayers, the visible light absorption range of JGSSe NTs is wider, and the large radius (>26.60 A) nanotubes all meet the hydrolysis potential. Surprisingly, the hole mobility of JGSSe NT was estimated to be as high as 2.89 × 104 cm2 V−1 S−1. In conclusion, JGSSe nanotubes are expected to be an excellent photocatalyst due to their low electron–hole recombination rate, high hole mobility, solar absorption in the visible light range, and good oxidation capacity. In addition, the nanotube band gap can be effectively regulated by applying strain. It is hoped that our research will provide meaningful progress in the development of novel and efficient photocatalysts. We hope that our research will provide a possible way to develop novel and efficient photocatalysts.
Pre-service physics teachers’ developing views on the role of mathematics in the teaching and learning of physics
Authors: de Winter James , Airey John 
Published: August 2022

Abstract
This qualitative, questionnaire and interview-based study explores how pre-service physics teachers think about the role that mathematics plays in the teaching and learning of physics at university and school level and whether these views change during their pre-service teacher education. Many of the pre-service teachers were aware of the complex relationship between these two subjects at university level, noting that success in mathematics can often mask a lack of conceptual understanding in physics and that there can be a disconnect between the physics and mathematical aspects of undergraduate courses. At school level, many stressed the importance of a focus on conceptual understanding and that technical competence in mathematics lessons does not always transfer to physics lessons. Almost all the pre-service physics teachers changed their views during the year, often in response to their classroom experiences. As they became more attuned to the difficulties students faced with respect to the mathematical challenges involved in learning physics, many took a more pragmatic position that balanced the role of mathematics in physics with acceptance that they must respond to student needs. We suggest that these changing views can be framed in terms of two re-orientations. A disciplinary re-orientation where the role that mathematics plays in order to be successful in physics is reassessed, and a pedagogical re-orientation that attends to pragmatic, teaching considerations. We recommend that direct attention to the role of mathematics in school physics should be an integral part of pre-service physics teacher education in order to encourage these re-orientations.
An online astronomy activity embedded with REACT strategy for preservice primary school teachers
Authors: Oktay Ozlem , Avci Zeynep , Sen Ahmet Ilhan 
Published: August 2022

Abstract
The purpose of this study was to provide an online astronomy activity using the Stellarium program as a virtual planetarium. The implementation was conducted with 30 preservice primary school teachers (PPTs) who participated in a non-formal workshop that included interactive, technology-based astronomy practices embedded with the Relate, Engage, Applying, Cooperating, Transferring strategy. The activity featured in the implementation covers the zodiac constellations and common related misconceptions, the duration of the Sun in the constellations, and the concepts of astronomy, astrology, and star clusters. At the end of the implementation, an online-survey was conducted to elicit feedback from the PPTs. According to the results of this study, PPTs enjoyed using Stellarium as a virtual planetarium. The PPTs were aware of certain astronomical concepts and misconceptions, stated that the activity content related to daily life, and that they gained skills related to astronomy teaching. The PPTs reported being satisfied with working in groups, and actively communicating actively with their peers. They suggested adding mythological stories while teaching the constellations. In addition, they proposed increased preliminary preparation and practice prior to the activity so as to gain basic pre-skills in using a virtual environment.
Deep learning method for reducing metal artifacts in dental cone-beam CT using supplementary information from intra-oral scan
Authors: Hyun Chang Min , Bayaraa Taigyntuya , Yun Hye Sun , Jang Tae-Jun , Park Hyoung Suk , Seo Jin Keun 
Published: August 2022

AbstractObjective.Recently, dental cone-beam computed tomography (CBCT) methods have been improved to significantly reduce radiation dose while maintaining image resolution with minimal equipment cost. In low-dose CBCT environments, metallic inserts such as implants, crowns, and dental fillings cause severe artifacts, which result in a significant loss of morphological structures of teeth in reconstructed images. Such metal artifacts prevent accurate 3D bone-teeth-jaw modeling for diagnosis and treatment planning. However, the performance of existing metal artifact reduction (MAR) methods in handling the loss of the morphological structures of teeth in reconstructed CT images remains relatively limited. In this study, we developed an innovative MAR method to achieve optimal restoration of anatomical details.Approach.The proposed MAR approach is based on a two-stage deep learning-based method. In the first stage, we employ a deep learning network that utilizes intra-oral scan data as side-inputs and performs multi-task learning of auxiliary tooth segmentation. The network is designed to improve the learning ability of capturing teeth-related features effectively while mitigating metal artifacts. In the second stage, a 3D bone-teeth-jaw model is constructed with weighted thresholding, where the weighting region is determined depending on the geometry of the intra-oral scan data.Main results.The results of numerical simulations and clinical experiments are presented to demonstrate the feasibility of the proposed approach.Significance.We propose for the first time a MAR method using radiation-free intra-oral scan data as supplemental information on the tooth morphological structures of teeth, which is designed to perform accurate 3D bone-teeth-jaw modeling in low-dose CBCT environments.