bluuebunny/crossref_metadata_2025 huggingface dataset:
Walkability in The Musamus University Campus Area
Authors: Sinambela Yohannes Putra Perkasa , Topan Anton , Mita Wijaya Maichel Santo
Published: December 2022

As an embodiment of meso-scale architecture, Musamus University must continue to improve itself to meet the needs of the growing activity actors in the campus environment. Pedestrian needs are the basis of an area that needs to be reviewed in this context. The movement of activity actors still uses motorized vehicles which results in spatial conflicts. This study aims to determine the walkability score of the Musamus University campus area and provide suggestions to improve the score so that it becomes an area that stimulates walking. The 6 urban attributes (variables) used to determine the walkability score according to the context of this area are connections to destinations, pedestrian comfort, legible, accessible,safe and pedestrian zones. Data, analysis and scoring of the walkability of the Musamus University campus area showed a score of 1.4 (not met). Availability of pedestrian paths; connectivity and continuity of the path; availability of shelters, seats and shade; disability facilities and strollers; conflicts with other modes of transportation; and pedestrian zones are the most influential walkability parameters.
Model of Vehicle Movement Pulling In Vocational High Schools In Ternate City
Authors: Hakim Raudha , Darwis Muhammad , Majid Hardian
Published: December 2022

School area is one type of land use that has a large enough appeal to the community. The number of vehicle modes can cause new problems in school areas which generally do not have special lanes to drop passengers. This study is to find out the number of pulls of vehicle movements, the characteristics of so unlucky economy and travel of students, teachers and employees, and make a model of pulling merger of vehicles in the educational area on the road K.H Dewantara Ternate city. Methods of collecting survey and questionnaire data, descriptive statistical analysis, correlation analysis, and multiple linear regression analysis. The results of the study on the number of vehicle movement pulls in SMA Negeri 1 Ternate City for 2-wheeled motor vehicles 743 vehicles, 4-wheeled vehicles 59 vehicles, SMK Negeri 1 Ternate City for 2-wheeled motor vehicles 654 vehicles, 4-wheeled vehicles 35 vehicles, SMA Negeri 10 Ternate City for 2-wheeled motorized vehicles as many as 512 vehicles, 4-wheeled vehicles 29 vehicles, and SMK Negeri 5 Kota for 2-wheeled motor vehicles 271 vehicles, 4-wheeled 18 vehicles. The results of the analysis of the best model of vehicle movement pull using a motor are Y1= 248.511 + 0.153 and the vehicle movement pull using a car is Y2 = -11.068 + 0.895 X1. Then the free variables used in this study also had a good influence on the pull of vehicles using a motorbike or by using car.
Identification of Good Opening Area During the Pandemic Classroom at the Faculty of Engineering Khairun University in Ternate
Authors: Tayeb Muhammad , Quraisy Sayyid
Published: December 2022

Good air distribution in the building should provide comfort and health for the wearer. This can be achieved through the design of more specific architectural sections or forms with the aim of maximizing the distribution of cool air. The target of this research is the Faculty of Engineering lecture hall which located on the Khairun Campus and is a new building with 3 floors. For this new normal period, lectures have reached 100 percent of students entering the room, so supporting facilities are needed that meet the requirements of thermal comfort and health protocols. This study aims to analyze good natural ventilation during endemic times in the lecture hall. This rese arch was conducted using quantitative – qualitative descriptive methods in analyzing the data. The results showed that lecture hall have an average temperature of 31.84 °C, with dampness of 68.47 percent and wind speed of 0.12 m/s. Thing This indicates that the thermal conditions in the lecture hall does not meet the standard of thermal comfort has a temperature exceeding 27.1°C, and a dampness level of more than 70 percent and must have a wind speed of 0.2m/s –2m/s. With this condition, the lecture hall has not yet met the standards of good natural good air distribution during the pandemic and has natural air that is not good for health the wearer
Préparation à la naissance et à la parentalité : l’effet de Halo ou quand les femmes enceintes éduquées éduquent à leur tour leur conjoint
Authors: Riquet Sébastien , Albano Maria Grazia , Memoli Noémie , Zakarian Carole , de la Tribonnière Xavier
Published: December 2022

Introduction :La préparation à la naissance et à la parentalité (PNP) est un programme de 7 séances d’une heure d’éducation réalisé par des sages-femmes à toutes les femmes enceintes qui le souhaitent. Les conjoints peuvent y participer, mais dans la majorité des cas, la transmission de connaissances et de compétences revient à la mère. L’existence de cette éducation « secondaire » a été démontrée dans le cadre de l’éducation thérapeutique (ETP) sous le nom d’« effet de Halo » Nous avons souhaité vérifier l’existence d’un tel effet dans le cadre de la PNP.Méthode :Des femmes enceintes ayant participé en 2021 à une PNP et leurs conjoints ont été soumis à deux questionnaires distincts à remplir durant le séjour à la maternité, suite à la naissance de leur enfant. Les réponses des mères (m) et des pères (p) ont été comparées.Résultats :96 mères (âge moyen : 31 ans) et 93 pères (âge moyen : 34 ans) ont répondu aux questionnaires. 97 % des mères (m) déclarent avoir transmis des connaissances/compétences au pères (p), ce que confirment 96 % d’entre eux. Pour les pères interrogés, cette transmission leur a permis de mieux comprendre les examens de dépistage obstétricaux (m = 78 % ;p = 80 %), les modifications physiques au cours de la grossesse (m = 75 % ;p = 82 %), le stress à devenir parent (m = 74 % ;p = 81 %), le choix de l’allaitement ou du biberon (m = 78 % ;p = 85 %) ainsi que les changements du sommeil des parents avec un nouveau-né (m = 80 % ;p = 82 %). Cet apprentissage permet aux pères d’apporter une aide significative à la mère au moment de l’accouchement et de la naissance (m = 83 % ;p = 93 %), dans la relation affective avec le bébé (m = 86 % ;p = 89 %) ainsi que dans sa gestion quotidienne (m = 82 % ;p = 82 %). Mères et pères émettent des opinions concordantes, sans écart statistiquement significatif. Les deux souhaitent que le père participe à la PNP, mais en partie seulement (m = 62 % ;p = 51 %).Discussion et conclusion :Notre étude confirme qu’il existe bien un effet de Halo. Les mères formées à la PNP éduquent à leur tour le père et en retirent pour elles-mêmes une aide utile au quotidien durant la période gestationnelle puis au post-partum. L’effet de Halo, qui se caractérise par une diffusion de compétences au-delà des premiers bénéficiaires de l’éducation, ouvre plusieurs perspectives de recherche et doit être pris en compte dans notre réflexion sur la vraie portée des programmes éducatifs en santé.
Management of Third and Fourth-Degree Perineal Tears After Vaginal Birth. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/079, December
2020)
Authors: Kropshofer Stephan , Aigmüller Thomas , Beilecke Kathrin , Frudinger Andrea , Krögler-Halpern Ksenia , Hanzal Engelbert , Helmer Hanns , Hölbfer Susanne , Huemer Hansjoerg , Van MoenieDer Kleyn , Kronberger Irmgard , Kuhn Annette , Pfeifer Johann , Reisenauer Christl , Tamussino Karl , Umek Wolfgang , Kölle Dieter , Abou-Dakn Michael , Gabriel Boris , Schwandner Oliver , Pristauz-Telsnigg Gunda , Welskop Petra , Bader Werner
Published: December 2022

Purpose This guideline provides recommendations for the diagnosis, treatment and follow-up care of 3rd and 4th degree perineal tears which occur during vaginal birth. The aim is to
improve the management of 3rd and 4th degree perineal tears and reduce the immediate and long-term damage. The guideline is intended for midwives, obstetricians and physicians involved in
caring for high-grade perineal tears.

Methods A selective search of the literature was carried out. Consensus about the recommendations and statements was achieved as part of a structured process during a consensus
conference with neutral moderation.

Recommendations After every vaginal birth, a careful inspection and/or palpation by the obstetrician and/or the midwife must be carried out to exclude a 3rd or 4th degree perineal
tear. Vaginal and anorectal palpation is essential to assess the extent of birth trauma. The surgical team must also include a specialist physician with the appropriate expertise (preferably
an obstetrician or a gynecologist or a specialist for coloproctology) who must be on call. In exceptional cases, treatment may also be delayed for up to 12 hours postpartum to ensure that a
specialist is available to treat the individual layers affected by trauma. As neither the end-to-end technique nor the overlapping technique have been found to offer better results for the
management of tears of the external anal sphincter, the surgeon must use the method with which he/she is most familiar. Creation of a bowel stoma during primary management of a perineal tear
is not indicated. Daily cleaning of the area under running water is recommended, particularly after bowel movements. Cleaning may be carried out either by rinsing or alternate cold and warm
water douches. Therapy should also include the postoperative use of laxatives over a period of at least 2 weeks. The patient must be informed about the impact of the injury on subsequent
births as well as the possibility of anal incontinence.
Seltene Erkrankungen: eine Kasuistik
Authors: Vill Peter
Published: December 2022

Im Medizinstudium lernt der angehende Arzt viele verschiedene Krankheiten kenne, wobei er zunächst nicht unterscheiden kann, welche häufig und welche selten vorkommen. Später, in der Routine des klinischen Alltags, wird dann schnell klar, welche Pathomechanismen und Krankheiten immer wieder auftauchen – aber alle selten vorkommenden laufen Gefahr, vergessen zu werden. Um jedoch bei seltenen Erkrankungen helfen zu können, müssen diese bekannt sein. Lebenslanges Lernen und Wiederholen ist daher unerlässlich. Der Beitrag stellt exemplarisch einen Praxisfall vor, in dem erst die Untersuchung auf einen genetischen COMT- und MAOA-Polymorphismus den Pathomechanismus der Symptomatik aufklären konnte.
Zugangswege zu Gesundheitsförderungsmaßnahmen
für Schwangere und junge Familien auf Landkreisebene am Beispiel der
GesundheitsregionPlus Landkreis Fürth
Authors: Rechberg Karl-Hermann , John Dennis , Przybyl Kristina
Published: December 2022

Hintergrund Der Landkreis Fürth hat im Rahmen der
GesundheitsregionPlus (https://www.gesundheitsregionenplus.bayern.de/) eine
Bedarfserhebung zu Maßnahmen der Gesundheitsförderung und
Prävention bei Schwangeren und jungen Familien durchgeführt.
Basierend auf qualitativem Interviewmaterial der Bedarfserhebung wird in diesem
Beitrag ein gegenstandsorientiertes, theoretisches Modell von Zugangswegen zu
Maßnahmen der Gesundheitsförderung und primären
Prävention in der GesundheitsregionPlus Landkreis Fürth
abgeleitet.

Methoden Es wurden insgesamt sieben Expertinnen und Experten sowie
insgesamt elf Schwangere bzw. Mütter interviewt. Um den Zugang zu
Maßnahmen der Gesundheitsförderung und primären
Prävention in der Bevölkerung genauer zu untersuchen, wurden die
Gespräche in Anlehnung an das Backward Mapping strukturiert. Die Daten
wurden im Rahmen einer qualitativen, strukturierenden Inhaltsanalyse nach
Mayring ausgewertet.

Ergebnisse und Schlussfolgerung Es können insgesamt drei Ebenen
des Zugangs im Hinblick auf die Randbedingungen unterscheiden werden, welche
dazu führen, dass Schwangere und junge Familien an einer
Maßnahme der primären Prävention &
Gesundheitsförderung (Präv/GF-Maßnahme) in der
GesundheitsregionPlus Landkreis Fürth teilnehmen: Ein erster Zugangsweg
erfolgt über Enkulturation, ein zweiter erfolgt über Motivation
und ein dritter Zugangsweg erfolgt über Empfehlungen. Abhängig
von Randbedingungen wie z. B. einer spezifischen
Gesundheitsförderungsmaßnahme kann eine der drei Zugangsebenen
den dominanten Zugang darstellen.
Catalyst-Free Reactions under Biocompatible Conditions
Authors: Loh Teck-Peng , Ren Mi , Lu Ming-Zhu
Published: December 2022

Catalyst-free biocompatible reactions are a class of green chemical processes that are also applicable to the field of chemical biology. In this account, we detail our journey in this exciting area of research since 2000. Various types of catalyst-free biocompatible reactions, such as the Mukaiyama aldol reactions and thiol-specific click reactions, and their applications to the functionalization of proteins are described. These reactions work well without destroying the three-dimensional structures of the proteins. Other reactions, including the C–SO2 and C–N bond-forming reactions, are also discussed. These reactions work in a truly green manner in which the use of organic solvents can be totally avoided. This toolbox of green chemical processes will certainly facilitate the work of researchers in the pharmaceutical industries.

1 Introduction

2 C–C Bond-Formation Reactions: The Mukaiyama Aldol Reaction

3 C–S Bond-Formation Reactions: Allenic Amide as the Electrophiles

4 C–SO2R Bond-Formation Reactions

4.1 Allylic Alcohols as the Electrophiles

4.2 Allenic Carbonyl Compounds as the Electrophiles

5 C–N Bond-Formation Reactions

6 Conclusions and Outlook
Morrison's Pouch: Anatomy and Radiological Appearance of Pathological Processes
Authors: Kaur Gurkawal , Kaur Tejinder , Das Chandan J.
Published: December 2022

Morrison's pouch is the intraperitoneal space in the supramesocolic compartment located between the right liver lobe and right kidney. Pathological conditions that can involve this peritoneal space include fluid collections, infectious or inflammatory processes, and neoplasms. Frequent involvement by disease entities can be attributed to its dependent location, communication with the inframesocolic compartment, close proximity to the adjacent organs and peritoneal fluid dynamics. Knowledge of the appearance of pathological entities on various imaging modalities helps the radiologist in making the correct diagnosis.
Space mission on gravitational waves gets boost from long-term LED study
Authors: Lim Alane
Published: December 2022

Scientists verify long-term performance of commercially available devices for an upcoming space-based gravitational-wave detection mission.
Physics-based model of irradiation creep for ferritic materials under fusion energy operation conditions
Authors: Yu Qianran , Po Giacomo , Marian Jaime
Published: December 2022

Irradiation creep is known to be an important process for structural materials in nuclear environments, potentially leading to creep failure at temperatures where thermal creep is generally negligible. While there is a great deal of data for irradiation creep in steels and zirconium alloys in light water reactor conditions, much less is known for first wall materials under fusion energy conditions. Lacking suitable fusion neutron sources for detailed experimentation, modeling, and simulation can help bridge the dose-rate and spectral-effects gap and produce quantifiable expectations for creep deformation of first wall materials under standard fusion conditions. In this paper, we develop a comprehensive model for irradiation creep created from merging a crystal plasticity representation of the dislocation microstructure and a defect evolution simulator that accounts for the entire cluster dimensionality space. Both approaches are linked by way of a climb velocity that captures dislocation-biased defect absorption and a dislocation strengthening term that reflects the accumulation of defect clusters in the system. We carry out our study in Fe under first wall fusion reactor conditions, characterized by a fusion neutron spectrum with average recoil energies of 20 keV and a damage dose rate of ≈3×10−7 dpa/s at temperatures between 300 and 800 K.
Decimations for one- and two-dimensional Ising and rotator models. II. Continuous vs discrete symmetries
Authors: D’Achille Matteo , van Enter Aernout C. D. , Le Ny Arnaud
Published: December 2022

We show how decimated Gibbs measures having unbroken continuous symmetry due to the Mermin–Wagner theorem, despite their discrete equivalents exhibiting phase transition, can still become non-Gibbsian. The mechanism rests on the occurrence of a spin-flop transition with a broken discrete symmetry, once the model is constrained by the decimated spins in a suitably chosen “bad” configuration.
Theoretical study on the correlation of swelling peaks between neutron and heavy ion irradiated 15-15Ti stainless steel
Authors: Wen A.-Li , Zhang Qiao-Li , Fan Ping , Ma Hai-Liang , Li Ke , Ren Cui-Lan , Huang He-Fei , Zhu Sheng-yun , Yuan Da-Qing
Published: December 2022

Titanium-modified austenitic stainless steels (15-15TiSS) are currently used as the fuel cladding material of fast reactors, which are subject to higher radiation damage during their application. In this work, the radiation-induced swelling of 15-15TiSS under a fast reactor neutron and heavy ion irradiation conditions was studied by the rate theory (RT). The simulated swelling properties of 15-15TiSS under fast neutron conditions were calculated initially. The swelling peak, swelling rates, and swelling-related microstructural properties are consistent with the neutron irradiation results, indicating that the selected RT model and material parameters are reasonable. Then, the swelling properties of 15-15TiSS under various damage rates were predicted by changing the radiation damage rates from 1 × 10−6 to 1 × 10−3 dpa/s. It shows that swelling peaks are strongly dependent on temperature and the swelling peaks shift ∼50 °C toward the higher temperature with each order of magnitude increase of defects generation rate. The swelling rates and swelling-related defect evolution at 1 × 10−3 dpa/s (with a swelling peak temperature of 590 °C) are consistent with that under neutron irradiation with 1 × 10−6 dpa/s (with a swelling peak temperature of 460 °C). At length, the RT-predicted heavy ions irradiation results were verified by the previous positron annihilation lifetime spectroscopy results of ions irradiated 15-15TiSS. It indicates that heavy ion irradiation can be used to study the radiation effect of materials under neutron irradiation and should be a feasible technique used in the further screening of radiation-resistant materials.
Low-noise and high-power second harmonic generation of 532 nm laser for trapping ultracold atoms
Authors: Wang Xuan-Kai , Zhou Zhao-Yu , Li Meng-Da , Zheng Yong-Guang , Zhang Wei-Yong , Su Guo-Xian , He Ming-Gen , Yuan Zhen-Sheng
Published: December 2022

Optical lattices for coherently manipulating ultracold atoms demand high-power, low-noise, narrow-line-width, and continuous-wave lasers. Here, we report the implementation of a 30 W 532 nm low-noise laser by second harmonic generation from a 1064 nm fiber laser, which is capable to generate optical lattices for a quantum gas microscope of Rb87 atoms. The overall conversion efficiency is 59% at an input power of 51 W with a lithium triborate crystal coupled to a ring cavity. The relative intensity noise of the output laser is suppressed to −120 dBc/Hz in the range of 10 Hz–100 kHz with a high dynamic range of over 50 dB, which is suitable for long-term trapping and coherent manipulation of the quantum gases.
Interplay of interactions in nanoparticle–surfactant complexes in aqueous salt solution
Authors: Singh Himanshi , Kumar Sugam , Aswal Vinod K.
Published: December 2022

The evolution of phase behavior and interactions in anionic silica nanoparticles (Ludox HS40), surfactants [non-ionic decaethylene glycol mono-dodecyl ether (C12E10) and anionic sodium dodecyl sulfate (SDS)], and nanoparticle–surfactant solutions in the presence of salt (NaCl) has been studied using small-angle neutron scattering and dynamic light scattering. In an anionic silica nanoparticle solution (1 wt. %), the phase behavior is controlled by salt concentrations (0–1 M) through screening electrostatic interactions. In the case of 1 wt. % surfactant solutions, the anionic SDS surfactant micelles show significant growth upon adding salt, whereas non-ionic surfactant C12E10 micelles remain spherical until a high salt concentration (1 M). In the mixed system of HS40–C12E10, a transition from a highly stable transparent phase to a two-phase turbid system is observed with a small amount of salt addition CS* (∼0.06 M). The single transparent phase of this system corresponds to sterically stabilized micelles-decorated nanoparticles. For the turbid phase, the results are understood in terms of depletion attraction induced by non-adsorption of C12E10 micelles, which explains the appearance of turbidity at a much lower concentration of salt. In the mixed system of similarly charged nanoparticles and micelles (HS40-SDS), the phase behavior is governed by no physical interaction between the components, and salt screens the repulsive interaction among nanoparticles. These results are further utilized to tune multicomponent interactions and phase behavior of nanoparticles with a mixed C12E10-SDS surfactant system in the presence of salt. The mixed surfactants provide tuning of nanoparticle–micelle as well as micelle–micelle interactions to dictate the phase behavior of a nanoparticle–surfactant solution. In these systems, the effective potential can be described by double-Yukawa potential taking account of attractive and repulsive parts at low and intermediate salt concentrations (CS*), the aggregation of nanoparticles is characterized by fractal aggregates.
Impact response of germanium over 300–1143 K temperature range
Authors: Zaretsky E. B. , Frage N. , Kalabukhov S.
Published: December 2022

Impact response of <111> oriented germanium single crystals and polycrystalline samples obtained by high-pressure spark plasma sintering of pure germanium powder was studied in two series of planar impact tests performed at 300 and 1143 K with samples of different thicknesses and in a series of tests with 2 mm single crystals preheated up to the temperatures 300–1143 K. In all the tests, the samples were shock-loaded by tungsten impactors having velocity 980 ± 40 m/s, while the velocity of the interface between the germanium sample and the fused silica window was continuously monitored by velocity interferometer. Under compression, the cubic diamond (cd) germanium transforms into its high-pressure (β-Sn or liquid) modification. The stress corresponding to the upper bound of the existence of impact loaded cd germanium was found to depart upward from that obtained in the static experiments. At temperatures greater than 900 K, this departure increases due to the initiation of melting in the shock-loaded material. Part of the velocity histories recorded with either single or polycrystalline samples was characterized by a four-wave (instead of the expected three-wave) structure. This “surplus” wave seems to be caused by a short-term existence of an intermediate (nonequilibrium) germanium phase which, however, does not affect the principal germanium Hugoniot.
A review of thermoreflectance techniques for characterizing wide bandgap semiconductors’ thermal properties and devices’ temperatures
Authors: Yuan Chao , Hanus Riley , Graham Samuel
Published: December 2022

Thermoreflectance-based techniques, such as pump–probe thermoreflectance (pump–probe TR) and thermoreflectance thermal imaging (TTI), have emerged as the powerful and versatile tools for the characterization of wide bandgap (WBG) and ultrawide bandgap (UWBG) semiconductor thermal transport properties and device temperatures, respectively. This Review begins with the basic principles and standard implementations of pump–probe TR and TTI techniques, illustrating that when analyzing WBG and UWBG materials or devices with pump–probe TR or TTI, a metal thin-film layer is often required. Due to the transparency of the semiconductor layers to light sources with sub-bandgap energies, these measurements directly on semiconductors with bandgaps larger than 3 eV remain challenging. This Review then summarizes the general applications of pump–probe TR and TTI techniques for characterizing WBG and UWBG materials and devices where thin metals are utilized, followed by introducing more advanced approaches to conventional pump–probe TR and TTI methods, which achieve the direct characterizations of thermal properties on GaN-based materials and the channel temperature on GaN-based devices without the use of thin-film metals. Discussions on these techniques show that they provide more accurate results and rapid feedback and would ideally be used as a monitoring tool during manufacturing. Finally, this Review concludes with a summary that discusses the current limitations and proposes some directions for future development.
MoSe2/PVA-based wearable multi-functional platform for pulse rate monitoring, skin hydration sensor, and human gesture recognition utilizing electrophysiological signals
Authors: Thomas Minu , Veeralingam Sushmitha , Badhulika Sushmee
Published: December 2022

Multifunctional wearable sensors have gained significant popularity in recent years for point of care diagnosis, tackling the myriad of obstacles faced in coping with health-related issues. However, complex fabrication, lack of biocompatibility, non-reusability, and accuracy limit their widespread use. In this work, we report a clean-room-free fabrication of molybdenum diselenide (MoSe2) interspersed with polyvinyl alcohol (PVA) based multifunctional device for in situ and non-invasive high-fidelity human gesture recognition, pulse rate monitoring, and skin hydration sensing. Detailed morphological characterization studies reveal the formation of a rhombohedral structure for MoSe2 nanoflakes stacked vertically to form a micro flower structure. Group synaptic activity of neurons results in a subtle electrical impulse, which, in turn, generates an electric field that is detected by the as-fabricated MoSe2/PVA device when attached to the forehead and interfaced to Open Brain-Computer Interface platform-based Cyton biosensing board. The device is also used as an ultrasensitive pressure sensor for arterial pulse pressure monitoring. This detection mechanism of the multifunctional sensor can be attributed to the piezoresistive effect of MoSe2 nanoparticles, wherein the dipoles reorient to form an internal polarization upon detection of physiological information. The strategy employed here paves the way toward replacing wet electrodes in conventional electroencephalogram (EEG)/electrocardiogram (ECG) measurements that result in skin abrasion and signal quality degradation with low-cost, reliable, skin-friendly, wearable MoSe2/PVA dry electrodes for rapid assessment.
Special quasirandom structures description of the local structure of disordered Bi0.5K0.5TiO3
Authors: Jiang Bo , Lin De-Ye , Wang Xin , Selbach Sverre M. , Page Katharine
Published: December 2022

Polar nanoregions (PNRs) are believed to play a decisive role in the local and macroscopic polarization in relaxor ferroelectrics. The limited microscopic understanding of the structure and dynamics of PNRs hampers the rational design of new lead-free materials. Here, the local structure of A-site disordered Bi0.5K0.5TiO3 (BKT) is investigated using synchrotron x-ray and neutron pair distribution function (PDF) analysis and density functional theory (DFT) optimized special quasirandom structures (SQSs). DFT-relaxed SQS with a 4 × 4 × 4 supercell size can reproduce the experimental PDFs of disordered BKT, as well as the partial PDFs and total polarization, with comparable results to those reported from a combined analysis of x-ray and neutron PDF data with large-box reverse Monte Carlo methods. We find that small Bi3+-rich polar clusters are likely to be the microscopic origin of relaxor behavior in disordered BKT, and that the existence of large polar nanoregions (PNRs) is not necessary to explain the relaxor properties. Our results also highlight the great potential of the SQS approach to gain a nanoscale-to-microscopic understanding of other relaxor solid solutions.
Construction of high performance nanocomposites based on a shape anisotropic soft phase: A micromagnetic simulation study
Authors: Teng Yuan , Li Yuqing , Yue Ming , Wang Jinjin , Liu Manying , Liu Weiqiang , Zhang Dongtao , Lu Qingmei , Wu Qiong , Zhang Hongguo , Yang Zhi
Published: December 2022

Nanocomposite permanent magnets are considered as a strong candidate for the next generation of high-performance permanent magnet materials due to their ultra-high theoretical magnetic energy product. In this paper, a nanocomposite theoretical model based on the shape anisotropy of the soft phase (Fe65Co35) is constructed to guide the improvement of coercivity, the lack of which has become a critical problem in improving the performance of Nd-Fe-B nanocomposites further. The results of micromagnetic simulation show that adding a shape anisotropic soft phase to nanocomposites can effectively improve coercivity, delay nucleation during the magnetization reversal process, and help obtain a demagnetization curve with high squareness. When the length size of the soft phase ds ≤ 21 nm and the aspect ratio of the soft phase I = 5 for the Nd2Fe14B/Fe65Co35 nanocomposites, almost square demagnetization curves can be obtained, particularly when ds = 21 nm, the size of the soft phase is 21 × 21 × 105 nm3, the content of the soft phase is 42.1 vol. %, and the Nd2Fe14B/Fe65Co35 nanocomposite achieves a maximum magnetic energy product of 94.4 MGOe. In addition, the results also show that, compared with the cubic nanocomposite model (I = 1), the larger size of the soft phase can be accommodated into the nanocomposites by the addition of shape anisotropy, on the premise of ensuring the soft–hard coupling effect. Our design provides a new strategy and approach for preparing high-performance nanocomposite permanent magnets.
Acoustic emission study on avalanche dynamics of ferroelectric switching in lead zirconate titanate ceramics
Authors: Shao Guomang , Xu Yangyang , Zhou Yumei , Ding Xiangdong , Sun Jun , Salje E. K. H. , Lookman Turab , Xue Dezhen
Published: December 2022

The avalanche dynamics of ferroelectric switching in lead zirconate titanate ceramics was investigated using acoustic emission. Two distinct power-law regimes for ferroelectric switching events were identified by an anomaly in the histogram of probability density, in contrast to the single power-law behavior observed in BaTiO3 single crystals. Such an anomaly is ascribed to the different minimum cut-offs of two power-law distributions. The critical energy exponents were determined to be 1.25 ± 0.10 for energies <103 aJ and 1.51 ± 0.14 for energies >103 aJ. The events in both regimes can be attributed to the depinning of domain walls from two distinct types of defects. The events in the lower energy regime are associated with domain wall junctions due to long-range electric and elastic interactions, whereas the latter is related to extrinsic defects, such as vacancies and dislocations. Moreover, for both regions, the rate of aftershocks follows the Omori power-law, indicating the same critical temporal correlations between the avalanches.
Perovskite quantum dots: Synthesis, applications, prospects, and challenges
Authors: Zou Jifan , Li Mengkai , Zhang Xiaoyu , Zheng Weitao
Published: December 2022

Metal-trihalide perovskite quantum dots combine the unique semiconducting properties of bulk perovskites with the controllable exciton dynamics benefiting from the quantum confinement effect. Composition- and size-adjustable electronic and optical properties of perovskites convert into a variety of applications. Here, we start from a brief introduction to perovskite quantum dots, followed by a detailed description of the synthesis methods and surface modification/passivation strategies of these nano-sized particles. Then, we review the applications of perovskite quantum dots including light-emitting diodes, photovoltaics, catalysis, sensing, bioimaging, and lasers. Finally, we develop outlooks for promising futures toward the commercial application of perovskite quantum dots.
Polarization retention dependence of imprint time within LiNbO3 single-crystal domain wall devices
Authors: Zhang Wen Di , Zhuang Xiao , Jiang Jun , Jiang An Quan
Published: December 2022

Ferroelectric LiNbO3 single crystals have wide applications in surface acoustic wave filters, pyroelectric sensors, and electro-optic modulators. Large-area LiNbO3 single-crystal thin films integrated on silicon are promising for high density integration of ferroelectric domain-wall resistance switching memories and transistors. However, the short-time operation of the memory often suffers from poor polarization retention due to the built-in imprint voltage. Here, we observed the strong polarization orientation-dependent imprint effect within either out-of-plane or in-plane LiNbO3 thin-film capacitors. The imprint effect can shift domain switching hysteresis loops toward positive/negative voltages seriously with written negative/positive polarizations that occur within a characteristic imprint time of 5.1 ms–360 s. Once the write time of the memory is shorter than the imprint time, the inverted domain is unstable and switches back into its previous orientation automatically after the termination of a write operation. However, the write failure can be avoided if the write time is longer than the imprint time, and the written domain can be deeply protected by the imprint field. A model of polarization-dependent charge injection at the interface is developed to explain the time-dependent imprint effect. For a mesa-like LiNbO3 memory cell in contact with two side electrodes fabricated at the film surface, the imprint time can be greatly shortened below 30 ns with the extension of one side electrode over the cell surface to screen the tail of the switched domain, enabling ferroelectric domain-wall resistance switching devices in excellent retention and high operation speeds.
In operando measurements of high explosives
Authors: Sellan Dhanalakshmi , Zhou Xuan , Salvati Lawrence , Valluri Siva Kumar , Dlott Dana D.
Published: December 2022

In operando studies of high explosives involve dynamic extreme conditions produced as a shock wave travels through the explosive to produce a detonation. Here, we describe a method to safely produce detonations and dynamic extreme conditions in high explosives and in inert solids and liquids on a tabletop in a high-throughput format. This method uses a shock compression microscope, a microscope with a pulsed laser that can launch a hypervelocity flyer plate along with a velocimeter, an optical pyrometer, and a nanosecond camera that together can measure pressures, densities, and temperatures with high time and space resolution (2 ns and 2 µm). We discuss how a detonation builds up in liquid nitromethane and show that we can produce and study detonations in sample volumes close to the theoretical minimum. We then discuss how a detonation builds up from a shock in a plastic-bonded explosive (PBX) based on HMX (1,3,5,7-Tetranitro-1,3,5,7-tetrazocane), where the initial steps are hotspot formation and deflagration growth in the shocked microstructure. A method is demonstrated where we can measure thermal emission from high-temperature reactions in every HMX crystal in the PBX, with the intent of determining which configurations produce the critical hot spots that grow and ignite the entire PBX.
Measurement technique of magnetic anisotropy field on patterned magnetic structures
Authors: Yoon Jaesung , Lee Seong-Hyub , Kim Minhwan , Kim Duck-Ho , Choe Sug-Bong
Published: December 2022

We propose an electric measurement technique for the magnetic anisotropy field of ferromagnetic thin films and their tiny patterned structures, particularly, in the case of in-plane magnetic anisotropy. This technique measures the anomalous Hall resistance by sweeping the angle or strength of the external magnetic field. The magnetic anisotropy field can be determined explicitly from the linear dependence of the Hall resistance on the angle and strength of the external magnetic field. The present technique can be applied to both ferromagnetic thin films and their patterned magnetic structures with small volumes, overcoming the signal resolution limit of conventional techniques.
Broadband microwave antenna for uniform manipulation of millimeter-scale volumes of diamond quantum sensors
Authors: Takemura Y. , Hayashi K. , Yoshii Y. , Saito M. , Onoda S. , Abe H. , Ohshima T. , Taniguchi T. , Fujiwara M. , Morishita H. , Ohki I. , Mizuochi N.
Published: December 2022

Quantum sensors based on nitrogen-vacancy (NV) centers in diamond are expected to demonstrate a wide variety of applications. For high-sensitivity quantum sensors with NV center ensembles, uniform manipulation of the electron spins of the NV centers in large volumes is required. In addition, a broad microwave frequency bandwidth for manipulating the NV centers' electron spin is necessary for vector magnetometry and measurement under a finite static magnetic field. Here, we demonstrate a broadband microwave antenna for uniform manipulation of millimeter-scale volumes of diamond quantum sensors. The simulation shows that the current is distributed at both edges of the loop coil of a single copper plate due to the skin effect. The loop coil acts like a Helmholtz coil, which realizes uniformity in the z-direction of the microwave magnetic field (B1). The plate structure has a higher mechanical stability, durability, and a larger heat capacity than the Helmholtz coil, due to its large volume. The antenna achieves a higher performance than previously reported antennae, with a maximal B1 of 4.5 G, a broad bandwidth of 287 ± 6 MHz, and a peak-to-peak variation of 9.2% over a 3.1 mm3 cylinder volume. These performances show that the presented antenna is suitable for manipulating solid-state spin ensembles for high-sensitivity quantum sensors.
Cavity magnonics for large and small amplitude precession
Authors: Iyaro J. , Stamps R. L.
Published: December 2022

Excitations that may appear in cavity magnonics experiments are examined with numerical micromagnetics using a recently developed semi-classical cavity magnonics theory. The theory is generally applicable to linear and nonlinear dynamic systems. In this paper, example applications of the theory for magnetic systems are presented where the dynamics is described using numerical micromagnetics for field driven ferromagnets. Examples of large amplitude driving are studied as a function of drive field amplitude and frequency. We comment also on large amplitude dynamics under elliptically polarized driving fields. The main conclusion is that when implemented together with micromagnetics, the theory can be used to describe cavity photon–magnon coupling for a wide variety of linear and nonlinear magnetic dynamics, thereby providing a useful technique for cavity magnonics.
Insights into nonvolatile resistive switching in monolayer hexagonal boron nitride
Authors: Mitra Sanchali , Mahapatra Santanu
Published: December 2022

A recent demonstration of nonvolatile resistive switching in monolayer hexagonal boron nitride (h-BN) has paved the way for the development of the thinnest memory devices feasible. Nevertheless, the exact mechanism of such remarkable resistive switching has remained obscure, which may hinder the optimization of such attractive technology. Here, we present the first dynamic description of the resistive switching process in a Ni/monolayer h-BN/Ni device at an atomistic level by employing reactive molecular dynamics simulations. We show that with the application of a suitable bias, the h-BN layer moves vertically and peels off Ni ions from the electrode, which gets adsorbed in the N vacancy center. From density-functional-theory based electron-localization-function calculations, we confirm that N vacancy generates highly delocalized electrons around the vacancy location resulting in the adsorption of Ni ions, though such a phenomenon is not likely in case of B vacancy due to the absence of electronic states around the defect center. We demonstrate the restoration of Ni ions with the application of reverse bias in case of bipolar switching, and by rising temperature in case of unipolar switching, which agrees with the experimental observations. Finally, we conduct ab initio quantum transport calculation to find an increase in zero-bias conductivity of about 7.4 times after the Ni ion adsorption. This atomistic insight enables precise defect-engineering in 2D materials for the realization of h-BN based high-performance memristive crossbar array.
Theory and practice of pulse compression in hybrid and gyromagnetic non-linear transmission lines
Authors: Rahman MuhibUr , Wu Ke
Published: December 2022

This paper presents a comprehensive analysis of pulse compression capability in hybrid and gyromagnetic non-linear transmission lines (NLTLs). The corresponding theoretical analysis in the hybrid NLTLs is derived and discussed in detail with the generation and sharpening aspects of leading and trailing pulse edges. The parameters responsible for pulse sharpening are examined and their corresponding pulse compression capability is modelled by providing the output waveform while varying these parameters. A holistic overview and mathematical development of gyromagnetic NLTLs are also conducted, which are modeled and validated through an equivalent lumped element model. Important parameters such as saturation magnetization, gyromagnetic NLTL sections, and damping parameter are elaborated and their influences on pulse sharpening and compression capability are studied. Validation of the theoretical and parametric analysis is performed by an experimental demonstration. The results achieved from hybrid and gyromagnetic NLTLs are briefly summarized, and their corresponding advantages and disadvantages are highlighted. This research is set to provide a fresh and successful debut for investigating gyromagnetic and hybrid NLTLs and their inherent effects on pulse compression for future ultrafast electronic systems and interconnects.
Optimized discrete unified gas kinetic scheme for continuum and rarefied flows
Authors: Wang Lu , Liang Hong , Xu Jiangrong
Published: December 2022

In this paper, an optimized discrete unified gas kinetic scheme (DUGKS) is presented for both continuum and rarefied flows. The present scheme can be considered as a new version of the DUGKS. At first, we follow the original DUGKS to obtain the evolution equation by finite volume method. Then, we propose a new method to evaluate the flux. Different from the original DUGKS, the flux is evaluated by the distribution function at the node instead of the interface center. This makes the present scheme easier to implement and more efficient than the original DUGKS. To validate the present scheme, several numerical tests are performed, including the doubly periodic shear layers, the canonical two-dimension, and three-dimension Taylor–Green vortex flows, as well as the pressure-driven Couette flow and micro-Couette flow. Numerical results demonstrate that the present scheme preserves almost the same accuracy as compared with the original DUGKS, while it exhibits a lower numerical dissipation, and the computational efficiency and numerical stability can be significantly improved.
Contrasting eddy-driven transport in baroclinically unstable eastward currents and subtropical return flows
Authors: Sutyrin G. G. , Radko T. , McWilliams J. C.
Published: December 2022

We identify and explore the fundamental differences in the dynamics of mesoscale vortices in eastward background (EB) parts in mid-latitude ocean gyres and in westward background (WB) return flows. In contrast to eddy behavior in EB flow, a systematic meridional drift of eddies in WB flow results in poleward expulsion of cold-core cyclones and equatorward expulsion of warm-core anticyclones from the unstable zone with a negative potential vorticity gradient (PVG). Consequently, heat can be transferred further by upper ocean vortices intrinsically coupled with deep opposite sign partners. Such structures can drift through the stable zone with positive PVG in both layers. This mechanism of lateral transfer is not captured by local models of homogeneous turbulence. The crossflow drift is related to the coupling of the upper vortices with opposite sign deep eddies shifted eastward. The abyssal vortices can be viewed as lee Rossby waves induced by their upper-layer partners and described analytically in the vicinity of latitude of marginal stability. Here, we show how such self-amplifying hetons, emerging in homogeneous turbulence, saturate when they approach locally stable regions of inhomogeneous currents. The presented results indicate that subtropical regions with return WB flows in the upper layer favor long-distance heat transport by spatially coherent eddies in accordance with observations and motivate the development of non-local parameterizations of eddy fluxes.
Dynamic response and acoustic characteristics of composite hydrofoil under cavitation-induced vibration
Authors: Dong Songwen , Duan Jinxiong , Sun Tiezhi
Published: December 2022

Nonconstant characteristics of cavitating flow can cause adverse effects, including vibration, noise, and cavitation. With the application of composite materials, the vibration and deformation of hydrofoils are becoming increasingly obvious, and the fluid–solid coupling problem is becoming very important. Herein, the cavitating flow field of National Advisory Committee for Aeronautics 0012 hydrofoil composed of bronze alloy and composite material is numerically investigated. The hydro-elastic response of a hydrofoil is obtained via a fluid–structure coupling method under a tight coupling strategy. The Schnerr–Sauer model is used to describe the cavitation process, and the large eddy simulation method is used to solve the turbulence problem. Additionally, the finite element method is used to determine the structural deformation. A comparison of the numerical calculation results of the fluid–solid acoustic coupling under two operating conditions shows that the composite materials can suppress the sheet cavitation attached to the hydrofoil suction surface and the tip leakage vortex (TLV) cavitation and can decrease the flow field pressure pulsation and increase the lift-to-drag ratio of the hydrofoil. Additionally, the composite material significantly improves the wake field turbulence, reducing the turbulence intensity and integration scale, and nearly eliminates the large-scale vortex. Moreover, the composite material changes the vortex structure evolution at the gap flow field, results in smoother TLV development, and enhances the flow field velocity gradient effect. Finally, the monitoring of the flow noise radiation characteristics shows that the composite material effectively reduces the sound pressure level of the self-noise and far-field radiation noise.