bluuebunny/crossref_metadata_2025 huggingface dataset:
WaterSegformer: A lightweight model for water body information extraction from remote sensing images
Authors: Yang Xiao , Chen Mingwei , Yu Chengjun , Huang Haozhe , Yue Xiaobin , Zhou Bei , Ni Ming
Published: December 2022

Accurate and efficient extraction of water body information from remote sensing images is of great help to monitor water resources at the macro level, natural disaster prediction, and water pollution detection and prevention. Although many large models have achieved extremely high accuracy in remote sensing image water segmentation tasks, lightweight models are still a non‐negligible choice for many application scenarios because of the limitation of computing and storage resources. Here, WaterSegformer is described, an efficient and powerful lightweight water body segmentation model based on Segformer‐b0. The Deepmask module is designed to make the model pay more attention to the details in the image and use Lovász loss to improve IoU. In addition, DeepLabv3+ is used as the teacher model to guide the training of the model in the way of relational knowledge distillation. WaterSegformer realizes 95.06% mIoU on the test set with only 6.38 G and 3.72 M of FLOPs and parameters, respectively. Experimental results show that WaterSegformer achieves an excellent balance between accuracy, computational complexity and model size, which is hardware‐friendly, easy to deploy and enables real‐time segmentation. This method provides a new idea for water body information extraction from remote sensing images in practical applications.
Algorithm of BPNN‐UKF based on a fusion model for SOC estimation in lithium‐ion batteries
Authors: Lin Jiashun , Yang Xiaoquan , Zhou Juan , Wang Guangming , Liu Jianshan , Yuan Yalei
Published: December 2022

Lithium‐ion batteries (LIBs) are widely used as energy storage devices. Accurately estimating the state of charge (SOC) is critical for the safe operation of LIBs, but the complex internal characteristics of LIBs make this a difficult task. In this study, an algorithm called BPNN‐UKF, which combines the backpropagation neural network (BPNN) and unscented Kalman filtering (UKF), is proposed. First, a fusion model construction method incorporating AdaBoost and recursive least squares (RLS) is developed to enhance the accuracy and generalization of the battery model. Next, the fusion model is applied to create BPNN‐UKF, which reduces the model dependence of UKF and the training requirements of BPNN. In this method, UKF estimates the SOC, and then BPNN learns the nonlinear relationship between SOC estimation error and process variables in UKF preliminary estimation. The BPNN output is used to update the state vector in real time during the new UKF estimation process. Experimental results reveal that the proposed method can drastically improve estimation accuracy compared with the UKF and the simple combined BPNN‐UKF, and it exhibits considerable generalization to common disturbances in SOC estimation and various battery working conditions.
Comparative analysis of photovoltaic performance metrics for reliable performance loss rate
Authors: Lee HyunYong , Lee Jungi , Kim Nac‐Woo , Lee Byung‐Tak
Published: December 2022

A reliable performance loss rate of photovoltaic systems requires accurate and reliable performance metrics. This study proposes a systematic method for assessing the performance metrics, particularly predicted power models in terms of both accuracy and uncertainty. The gist of the proposed method is to examine how accurately a predicted power model predicts the manipulated degradation in a controlled environment. For this, the proposed method divides a given dataset evenly into base data (to generate reference performance) and test data (to generate test performance via manipulation) so that the two data have similar features. The proposed method also utilizes the bootstrap iteration to derive a reliable assessment. The novelty of this study is that the proposed method estimates both the accuracy and uncertainty of arbitrary predicted power models, which is missing in existing works. Extensive experiments using the proposed method with real‐world datasets reveal the followings. One interesting observation is that a well‐known machine learning prediction model, not considered in existing works, exhibits the best performance in terms of both accuracy and uncertainty. Existing predicted power models require different experiment settings to produce reliable performance. The number of test data is closely related to uncertainty, but not much related to accuracy.
Einweginstrumente statt Mehrfachverwendung – Ist der Trend zu
Einmalinstrumentarium in der Endoskopie ökologisch
vertretbar?
Authors: Güner Taner , Schmitt Sabine , Eickhoff Axel
Published: December 2022

Hunderttausende gingen zuletzt während der “Fridays for
future” Bewegung für mehr Ökologie und Klimaschutz auf
der Straße und demonstrierten für mehr Nachhaltigkeit im Umgang
mit endlichen Ressourcen. Auch in Krankenhäuser und anderen
medizinischen Einrichtungen nimmt dies einen immer höheren Stellenwert
ein. Der Gesundheitssektor ist für 5,6% aller deutschlandweiten
C02-Emissionen verantwortlich, insbesondere durch den hohen Energieverbrauch und
den anfallenden Müll von 6 kg/d pro Patient. Dabei sind
heute die Endoskopie-Abteilungen neben OP und Radiologie die 3.
größten Müllverursacher in den Kliniken. Flexible
Endoskopien stellen einen potentiellen Risikofaktor für klinisch
bedeutsame Infektionen dar. Relevant sind dabei exogene Infektionen, die durch
eine Übertragung von kontaminiertem Material über Endoskope und
des endoskopischen Zubehörs (Zangen, Schlingen, Clips etc.) auftreten
können. Der Trend zum endoskopischen Einweginstrumentarium begann vor
über 20 Jahren und inzwischen sind fast alle in der flexiblen Endoskopie
verwendeten Produkte Einmalmaterialien. In den letzten 5 Jahren wird vermehrt
über den Einsatz von Einmal-Endoskopen diskutiert und inzwischen sind
neben den bekannten Einweg-Bronchoskopen auch die ersten Einweg-Duodenoskope und
Gastroskope zugelassen. Bei den grundsätzlich von jedem Patienten
ausgehenden Kontaminations- und Infektionsrisiken wäre aus rein
hygienischer Sicht die Nutzung von Einmal-Endoskopen für jeden Patienten
wünschenswert, was aber bei der aktuellen Kosten- und
Vergütungsstruktur gesundheitsökonomisch und insbesondere auch
ökologisch sehr diskussionswürdig erscheint. Ob hierdurch eine
höhere Patientensicherheit und bessere Behandlungsqualität
erzielt wird, kann theoretisch vermutet jedoch klinisch nicht bewiesen werden.
Zukünftig werden für die Beurteilung und Auswahl unserer
Endoskope/Zubehör nicht nur wie bisher medizinische und
ökonomische Faktoren herangezogen, sondern insbesondere auch die
ökologischen Folgen verstärkt in den Fokus rücken. Die
Fachgesellschaften und Ärzte aber auch die Medizinproduktebetreiber
müssen sich dieser Herausforderung stellen. Zu fordern ist hier an
allererster Stelle eine reale und valide Analyse des sogenannten
CO2-Fußabdrucks bzw. der Klimabilanz der verwendeten Instrumente und
Endoskope inklusive der Möglichkeit, diese einem adäquaten
Recyclingprozess zuführen zu können.
Vermeidung drogeninduzierter Mortalität nach
Haftentlassung
Authors: Stöver Heino , Michels IngoIlja
Published: December 2022

Die Haftentlassung stellt für Konsumierende von Opioiden einen riskanten
Übergang in die Freiheit dar. Insbesondere innerhalb der ersten
10–14 Tage liegt das Risiko einer drogeninduzierten
Überdosierung, im schlimmsten Fall mit Todesfolge, besonders hoch.
Medizinische Maßnahmen zur Vermeidung dieser gesundheitlichen Risiken
für die Zielgruppe sind zum einen eine kontinuierliche
substitutionsgestützte Behandlung vor, während und nach der
Inhaftierung, und zum anderen die Aufklärung über und der Zugang
zu Naloxon als Antidot bei Opioidüberdosierung. Dieser Beitrag gibt
einen Überblick über die aktuellen Zahlen zu Drogentoten nach
Haftentlassung in Deutschland sowie über bestehende wissenschaftliche
Erkenntnisse zur Wirksamkeit von substitutionsgestützter Behandlung und
Naloxon-Vergabe in der Versorgung von Opioidkonsumierenden an der Schnittstelle
zwischen Haft und Freiheit. Schließlich werden notwendige
Maßnahmen zur Vermeidung von drogeninduzierten Überdosierungen
mit Todesfolge aufgezeigt. Hierfür wurden eine selektive
Literaturrecherche sowie eine Befragung der Landeskriminalämter in 16
Bundesländern durchgeführt, um einen Überblick
über die aktuelle Situation in Deutschland zu erhalten.
Nicht zervikogener Schwindel, sondern Benigner Paroxysmaler Lagerungsschwindel
Authors: Schädler Stefan
Published: December 2022

Patient*innen, die sich mit der Diagnose „Zervikogener Schwindel“ in der physiotherapeutischen Praxis vorstellen, sind in einigen Fällen fehldiagnostiziert und leiden eigentlich unter einem gutartigen Lagerungsschwindel. Oft stellt sich dabei die Frage: Wie wird ein benigner paroxysmaler Lagerungsschwindel (BPLS) erkannt und erfolgreich behandelt? In diesem Artikel werden die Grundlagen des BPLS und des zervikogenen Schwindels dargestellt und aufgezeigt, wie diese differenziert werden können. Anhand dreier exemplarischer Fallbeispiele von Patient*innen mit der Diagnose „Zervikogener Schwindel“ wird dargelegt, wie Physiotherapeut*innen mittels Anamnese und hypothesengesteuerter Untersuchung einen BPLS identifizieren und mit entsprechendem Manöver erfolgreich behandeln können. Ein BPLS erfordert andere Behandlungstechniken als ein zervikogener Schwindel und benötigt in der Regel nur wenige Sitzungen.
„Jetzt geht gar nichts mehr, totale Blockade.“ Ein Fallbeispiel
Authors: Orthmayr Klaus
Published: December 2022

Seit 2 Jahren plagen Mia episodenweise starke Rücken- und Beinschmerzen. Sich an einem Clinical Reasoning Framework orientierend analysiert Klaus Orthmayr zusammen mit Mia Ursachen und Treiber der Schmerzen. Gemeinsam entwickeln sie Strategien, die Schmerzen in den Griff zu bekommen. Ein Fall, spannend wie ein Detektivroman.
Ellenbogenfrakturen – operative vs. konservative Therapie und
Nachbehandlung
Authors: Hubbe Johannes
Published: December 2022

Das Ellenbogengelenk reagiert auf eine über 14 Tage hinausgehende
Ruhigstellung sehr sensibel und neigt zur Einsteifung. Als zusammengesetztes
Gelenk mit einer schlaffen Kapsel und stabilisierenden Bändern verdienen
die Knochen-Band-Verbindungen besonderes Augenmerk. Wegen der engen
funktionellen Beziehungen ist die Beurteilung der Unterarm- und Handfunktion
unabdingbar. Konservative und postoperative Behandlungen sind von hoher
Schmerzempfindlichkeit und reflektorischer Muskelspannung geprägt.
Cognitive and Brain Gray Matter Changes in Children with Obstructive Sleep Apnea: A Voxel-Based Morphological Study
Authors: Hongbin Li , Zhuo Li , Guixiang Wang , Jing Zhao , Hua Wang , Yue Liu , Binbin Nie , Jie Zhang , Jun Tai , Xin Ni
Published: December 2022

Background To explore the neural difference between children with obstructive sleep apnea (OSA) and healthy controls, together with the relation between this difference and clinical severity indicator of children with OSA.

Methods Twenty-seven children with OSA (7.6 ± 2.5 years, apnea hypopnea index [AHI]: 9.7 ± 5.3 events/h) and 30 healthy controls (7.8 ± 2.6 years, AHI: 1.7 ± 1.2 events/h) were recruited and matched with age, gender, and handedness. All children underwent 3.0 T magnetic resonance imaging of the brain and cognitive testing evaluating. Volumetric segmentation of cortical and subcortical structures and voxel-based morphometry were performed. Pearson's correlation analysis was performed between these features of gray matter volume (GMV) and obstructive apnea index (OAI) among children with OSA.

Results In the comparison of children's Wechsler test scores of full-scale intelligence quotient and verbal intelligence quotient, the OSA group was significantly lower than the control group (p < 0.05). Compared with the control group, the GMV of many brain regions in the OSA group was significantly decreased (p < 0.05). In the correlation analysis of GMV and OAI in OSA group, right inferior frontal gyrus volume was significantly negatively correlated with OAI (r = − 0.49, p = 0.02).

Conclusion Children with OSA presented abnormal neural activities in some brain regions and impaired cognitive functions. This finding suggests an association between the OSA and decreased GMV in children.
Point of Care Virtual Surgical Planning and 3D Printing in Facial Feminization Surgery
Authors: Sharaf Basel , Kuruoglu Doga , Bite Uldis , Morris Jonathan M.
Published: December 2022

The use of virtual surgical planning (VSP) and three-dimensional printing (3DP) technologies in the routine facial feminization surgery practice has gained a significant popularity over the past few years. The clinical applications of them are claimed to improve safety, accuracy, and efficiency of facial feminization surgeries. In this article, we review and discuss the current applications of VSP and 3DP in different facial feminization procedures.
Knowns and unknowns in the Davydov model for energy transfer in proteins
Authors: Cruzeiro Leonor
Published: December 2022

The Davydov model for amide I propagation in hydrogen-bonded chains of proteins is revisited. The many similarities between the mixed quantum-classical dynamical equations and those that are derived from the full quantum Davydov model while applying the so-called D2 ansatz are highlighted. The transition from a minimum energy localized amide I state to a fully delocalized state is shown to operate in four phases, one of which is abrupt and the last of which is a fast but smooth change from a very broad yet localized state to a completely delocalized one. Exploration of the dynamical phase space at zero temperature includes the well-known soliton propagation as well as double and triple discrete breathers, and dispersion of initially localized states. The uncertainties related to the question of the thermal stability of the Davydov soliton are illustrated. A solution to the seemingly endless problem of the short radiative lifetime of the amide I excitations is proposed.
Intrinsic localized modes in polymers and hyperconductors
Authors: Russell F. Michael , Archilla Juan F. R.
Published: December 2022

The history of the experimental study of nonlinear lattice excitations in layered silicate materials, when exposed to swift particles of appreciable momentum is described briefly. For brevity, and because of the difficulty of studying the structure of the lattice excitations, the term quodon was adopted to reflect their ballistic and quasione-dimensional propagative nature. Quodons in muscovite were observed experimentally. Eventually, it was deduced that the lattice excitations were carrying an electric charge. This led to the prediction of hyperconductivity (HC) in which charge is carried ballistically by neutral, mobile lattice excitations in absence of a driving electromotive force and at any temperature. HC was later observed experimentally. For practical applications of HC, it is necessary to encase the HC material in an insulating sheath. This focused attention on the behavior of insulating materials in the presence of quodons. These could enter the sheath by direct contact with the HC material or by the impact of the swift particles. It was found that quodons can exist and propagate in many different materials, perhaps all, but their behavior can vary dramatically. This universality and charge neutrality, together with their unexpected existence in the excellent insulator polytetrafluoroethylene, probably accounts for the delay in finding evidence of their existence.
Quasi-steady state propagation in the davydov-type model with linear on-site interactions
Authors: Cisneros-Ake Luis A.
Published: December 2022

The problem of electron transportation along a discrete deformable medium with linear on-site interactions in the Davydov approach is considered. It is found that the quasi-stationary state of the full equations of motion leads to a discrete nonlocal nonlinear Schrödinger (DNNLS) equation whose nonlocality is of the exponential type and depending on the on-site parameter. We use the variational approach to approximate discrete traveling wave solutions in the DNNLS equation. We find that the discrete solutions continued from the discrete nonlinear Schrödinger equation, corresponding to the vanishing of the on-site parameter, bifurcates in a critical on-site value. Additionally, a threshold in the velocity of propagation of the discrete structures is found.
Small-sized x-band open resonator for wide-range permittivity measurements of solid-state dielectrics
Authors: Breslavets A. A. , Eremenko Z. E. , Rudnev G. O. , Natarov M. P. , Glamazdin V. V. , Shubnyi O. I. , Voitovych O. A. , Gang Zhu , Rong Li , Prokopenko A. A.
Published: December 2022

A study using computer simulation of a compact two-mirror symmetric open resonator for use in the X band for measurements of the complex permittivity of flat samples was carried out. The possibilities of minimizing the dimensions of an open resonator with a loaded quality factor of about 104 are investigated. Comparative studies of various coupling elements of an open resonator with a waveguide are carried out. It is shown that coupling elements in the form of a slot on the mirror, which smoothly passes into a standard waveguide, have advantages for use in open resonator for permittivity measurements, compared with coupling elements in the form of a hole in the diaphragm at the end of waveguide on the mirror surface. It is shown that slot coupling elements make it possible to achieve in open resonators almost twice as much field magnitude than coupling elements in the form of holes.
Rank one perturbations supported by hybrid geometries and their deformations
Authors: Erman Fatih , Seymen Sema , Turgut O. Teoman
Published: December 2022

We study the hybrid type of rank one perturbations in R2 and R3, where the perturbation supported by a circle/sphere is considered together with the delta potential supported by a point outside of the circle/sphere. The construction of a self-adjoint Hamiltonian operator associated with formal expressions for the rank one perturbation supported by a circle and by a point is explicitly given. Bound state energies and scattering properties for each problem are also studied. Finally, we consider the rank one perturbation supported by a deformed circle/sphere and show that the first order change in bound state energies under small deformations of the circle/sphere has a simple geometric interpretation.
Nitrogen related paramagnetic defects: Decoherence source of ensemble of NV− center
Authors: Shinei Chikara , Masuyama Yuta , Miyakawa Masashi , Abe Hiroshi , Ishii Shuya , Saiki Seiichi , Onoda Shinobu , Taniguchi Takashi , Ohshima Takeshi , Teraji Tokuyuki
Published: December 2022

We investigated spin-echo coherence times T2 of negatively charged nitrogen vacancy center (NV−) ensembles in single-crystalline diamond synthesized by either the high-pressure and high-temperature and chemical vapor deposition methods. This study specifically examined the magnetic dipole–dipole interaction (DDI) from the various electronic spin baths, which are the source of T2 decoherence. Diamond samples with NV− center concentration [NV−] comparable to those of neutral substitutional nitrogen concentration [Ns0] were used for DDI estimation. Results show that the T2 of the ensemble NV− center decreased in inverse proportion to the concentration of nitrogen-related paramagnetic defects [NPM], being the sum of [Ns0], [NV−], and [NV0], which is a neutrally charged state NV center. This inversely proportional relation between T2 and [NPM] indicates that the nitrogen-related paramagnetic defects of three kinds are the main decoherence source of the ensemble NV− center in the single-crystalline diamond. We found that the DDI coefficient of NVH− center was significantly smaller than that of Ns0, the NV0 center, or the NV− center. We ascertained the DDI coefficient of the NV− center DNV− through experimentation using a linear summation of the decoherence rates of each nitrogen-related paramagnetic defect. The obtained value of 89 μs ppm for DNV− corresponds well to the value estimated from the relation between DDI coefficient and spin multiplicity.
Photoelectron tomography with an intra-cavity velocity-map imaging spectrometer at 100 MHz repetition rate
Authors: Oelmann J.-H. , Heldt T. , Guth L. , Nauta J. , Lackmann N. , Wössner V. , Kokh S. , Pfeifer T. , López-Urrutia J. R. Crespo
Published: December 2022

We present a compact velocity-map imaging (VMI) spectrometer for photoelectron imaging at 100 MHz repetition rate. Ultrashort pulses from a near-infrared frequency comb laser are amplified in a polarization-insensitive passive femtosecond enhancement cavity. In the focus, multi-photon ionization (MPI) of gas-phase atoms is studied tomographically by rotating the laser polarization. We demonstrate the functioning of the VMI spectrometer by reconstructing photoelectron angular momentum distributions from xenon MPI. Our intra-cavity VMI setup collects electron energy spectra at high rates, with the advantage of transferring the coherence of the cavity-stabilized femtosecond pulses to the electrons. In addition, the setup will allow studies of strong-field effects in nanometric tips.
Implementation of high-resolution spectroscopy for ion (and electron) temperature measurements of the divertor plasma in the Tokamak à configuration variable
Authors: Martinelli L. , Mikitchuck D. , Duval B. P. , Andrebe Y. , Blanchard P. , Février O. , Gorno S. , Elaian H. , Linehan B. L. , Perek A. , Stollberg C. , Vincent B. ,   TCV Team
Published: December 2022

High resolution spectroscopy on the Tokamak à Configuration Variable (TCV) divertor plasma provided Doppler broadening measurements to infer the ion and neutral temperature of injected helium gas. This paper presents the Divertor Spectroscopy System’s (DSS) access to He II ion temperature measurements over a broad range, ≈0.5–15 eV, with an uncertainty of <10% for most of the studied plasma discharges. TCV’s shaping flexibility was employed to validate these measurements against Thomson scattering across the DSS lines of sight. In detachment-related experiments, Ti(He II) ≃ Te, making this diagnostic a reliable thermometer along the divertor leg plasma over the wide range of magnetic equilibria and divertor configurations achievable in TCV. A detailed description of the diagnostic hardware, data analysis, and sources of uncertainty is presented.
Monte Carlo N-Particle forward modeling for density reconstruction of double shell capsule radiographs
Authors: Byvank T. , Meyerhofer D. D. , Keiter P. A. , Sagert I. , Martinez D. A. , Montgomery D. S. , Loomis E. N.
Published: December 2022

In the Double Shell Inertial Confinement Fusion concept, characterizing the shape asymmetry of imploding metal shells is vital for understanding energy-efficient compression and radiative losses of the thermonuclear fuel. The Monte Carlo N-Particle MCNP® code forward models radiography of Double Shell capsule implosions using the Advanced Radiographic Capability at the National Ignition Facility. A procedure is developed for using MCNP to reconstruct density profiles from the radiograph image intensity. For a given Double Shell imploding target geometry, MCNP radiographs predict image contrast, which can help guide experimental design. In future work, the calculated MCNP synthetic radiographs will be compared with experimental radiographs to determine the radial and azimuthal density profiles of the Double Shell capsules.
Integrated measurement of thermoelectric properties for filamentary materials using a modified hot wire method
Authors: Lu Rui , Yang Xiao , Wang Chunyang , Shen Yanan , Zhang Ting , Zheng Xinghua , Chen Haisheng
Published: December 2022

Thermoelectric materials have been rapidly developed due to the urgent need for the mutual conversion of thermal energy and electrical energy. Accurately measuring the thermoelectric properties of micro/nano thermoelectric materials is very important and highly required. Compared with traditional measurement methods, integrated measurement can avoid multiple sample preparations and reduce measurement errors. Herein, this work designed an improved integrated measurement method for the thermoelectric properties of microscale thermoelectric materials based on the hot wire method. The results demonstrated that the average ZT values of Pt and Ag2S wires are 0.75 × 10−3 and 0.44 × 10−3 with an uncertainty of ∼2.61%. It provides a novel way for the development of accurately measuring the thermoelectric properties of thermoelectric materials.
Schottky barrier height engineering in vertical p-type GaN Schottky barrier diodes for high-temperature operation up to 800 K
Authors: Aoyama Kohei , Ueno Kohei , Kobayashi Atsushi , Fujioka Hiroshi
Published: December 2022

We have fabricated vertical p-type gallium nitride (GaN) Schottky barrier diodes (SBDs) using various Schottky metals such as Pt, Pd, Ni, Mo, Ti, and Al. Current–voltage characteristics revealed that Schottky barrier heights determined using a thermionic emission (TE) model (ϕBTE) were ranged between 1.90 eV for Pt and 2.56 eV for Mo depending on the work function (ϕm) of the Schottky metals. Despite their low ϕm, Ti and Al gave unusually small ϕBTE probably due to the interfacial reaction between metal and p-type GaN. We also found that Mo/p-GaN SBDs exhibited a clear rectifying property even at 800 K, and the thermionic emission diffusion (TED) model explained well their high-temperature I–V characteristics. Furthermore, the temperature variation of Schottky barrier heights determined using a TED model (ϕBTED) almost agrees with half of the temperature variation of the bandgap energy. These findings will be helpful for the application of p-type GaN Schottky interfaces to high-power and high-temperature electronics.
Fabrication of tungsten tips with controllable shape by a two-step rapid reciprocating electrochemical etching method
Authors: Sun Yiming , Deng Hanwen , Liu Xinyu , Kang Xiaoming
Published: December 2022

Traditional electrochemical etching methods for the needle of a liquid metal ion source (LMIS) easily produce an exponential profile with an uncontrollable tip length and apex radius. Meanwhile, a ledge forms between the needle tip and the needle rod under the etching of the meniscus, which becomes an obstacle for the flow and replenishment of the liquid metal. This paper proposed a two-step rapid reciprocating etching method, which aims to fabricate LMIS tungsten needles with controllable tip length and apex radius, and also with a smooth transition region between the needle tip and the needle rod. In the first step of rough machining, the needle rapidly reciprocates up and down in the electrolyte and rotates to produce a uniform conical profile. However, an ellipsoidal residual portion is generated concomitantly at the needle tip. In the second step of finish machining, the needle shifts down for a given distance and continues to reciprocate until the sharp tip is formed. The tip length fabricated varied from 0.59 to 5.53 mm at different reciprocating strokes. The apex radius ranged from 0.3 to 0.7 µm, and can also be increased to 2 µm by extra reciprocate etching in the electrolyte to meet the LMIS working requirement. A variable named transitivity was defined to quantitatively describe the smoothness of the region between the tip and rod during the etching process. The experimental results showed that a rotation speed of 600 rpm combined with a reciprocating speed of 0.5 mm/s can significantly improve the transitivity of the needle. Those fabricated needle tips have been tested for the indium LMIS and the maximum emission current of the needle tip reached 12 µA.
Flow induced by a pair of plasma actuators on a circular cylinder in still air under duty-cycle actuation
Authors: Hui Weiwei , Meng Xuanshi , Li Huanxing , Liu Feng
Published: December 2022

A pair of surface mounted dielectric-barrier-discharge (DBD) plasma actuators is placed diametrically on a circular cylinder model. The flow field generated by the actuators in steady and duty-cycle actuation modes is measured by particle image velocimetry. Salient features of the flow and vortices are discovered for the duty-cycle actuation modes with frequency ranging from 5 to 1000 Hz and duty-cycle ratio from 0.01 to 0.99. The results are compared with those for continuous steady actuation. For a given duty-cycle ratio, a discrete vortex is generated by each of the DBD actuator in an actuation cycle for low frequencies. Such vortices are created alternately from each side of the cylinder. They interact and move laterally in response to the on-off signals of the actuators. As the frequency increases, the distance between the vortices generated from successive duty-cycles decreases and the lateral motion of the vortices becomes smaller so that the vortices are packed together as a vortex train along a narrow path on each side of the cylinder. As the frequency is further increased, the vortices in the vortex trains lose their individual characteristics and the vortex trains become steady jets. Regardless of the actuation frequency, the direction of the average total momentum of the air is found to be continuously dependent on the duty-cycle ratio. The magnitude of the average total momentum depends on the frequency. An optimum frequency exists for maximum average momentum, which may exceed that in the continuous steady actuation mode.
Computational description of surface hydride phases on Pt(111) electrodes
Authors: Hanselman Selwyn , Calle-Vallejo Federico , Koper Marc T. M.
Published: December 2022

Surface platinum hydride structures may exist and play a potentially important role during electrocatalysis and cathodic corrosion of Pt(111). Earlier work on platinum hydrides suggests that Pt may form clusters with multiple equivalents of hydrogen. Here, using thermodynamic methods and density functional theory, we compared several surface hydride structures on Pt(111). The structures contain multiple monolayers of hydrogen in or near the surface Pt layer. The hydrogen in these structures may bind the subsurface or reconstruct the surface both in the set of initial configurations and in the resulting (meta)stable structures. Multilayer stable configurations share one monolayer of subsurface H stacking between the top two Pt layers. The structure containing two monolayers (MLs) of H is formed at −0.29 V vs normal hydrogen electrode, is locally stable with respect to configurations with similar H densities, and binds H neutrally. Structures with 3 and 4 ML H form at −0.36 and −0.44 V, respectively, which correspond reasonably well to the experimental onset potential of cathodic corrosion on Pt(111). For the 3 ML configuration, the top Pt layer is reconstructed by interstitial H atoms to form a well-ordered structure with Pt atoms surrounded by four, five, or six H atoms in roughly square-planar and octahedral coordination patterns. Our work provides insight into the operando surface state during low-potential reduction reactions on Pt(111) and shows a plausible precursor for cathodic corrosion.
Magnetism and microstructure of co-deposited yttrium iron garnet-barium titanate films
Authors: Su Tingyu , Ross Caroline A.
Published: December 2022

Yttrium iron garnet (YIG) and barium titanate (BTO) were co-deposited on (001)-orientated gadolinium gallium garnet substrates by pulsed laser deposition with composition determined by the ratio of laser shots ablating each target. With increasing shot ratios of YIG/BTO = 2.5/1, 4/1, 20/1, and 30/1, the majority phase in the film changes from textured polycrystalline perovskite to epitaxial garnet. Cross-sectional STEM characterization of the YIG-rich films reveals three distinct sublayers: the bottom layer is a coherent epitaxial garnet layer with higher unit cell volume than that of YIG; the second layer is garnet exhibiting crystalline defects and misorientation; and the upper layer is amorphous. Highly defective regions within the second layer are richer in Ba, suggesting that the microstructure is promoted by the insolubility of Ba in YIG. Temperature-dependent magnetization measurements fitted to a super-exchange dilution model indicate the presence of nonmagnetic Ti and vacancies in both octahedral and tetrahedral sites.
Rheology, crystallization, and process conditions: The effect on interlayer properties in three-dimensional printing
Authors: Das Arit , Riet Jocelyn A. , Bortner Michael J. , McIlroy Claire
Published: December 2022

Semicrystalline polymers are an attractive feedstock choice for material extrusion (MatEx)-based three-dimensional printing processes. However, the printed parts often exhibit poor mechanical properties due to weak interlayer strength thereby limiting the widespread adoption of MatEx. Improved interlayer strength in the printed parts can be achieved through a combination of process parameter selection and material modification but a physics-based understanding of the underlying mechanism is not well understood. Furthermore, the localized thermal history experienced by the prints can significantly influence the strength of the interlayer welds. In this work, a combined experimental and modeling approach has been employed to highlight the relative impact of rheology, non-isothermal crystallization kinetics, and print geometry on the interlayer strength of printed parts of two semicrystalline polymers, namely, polylactic acid (PLA) and polypropylene (PP). Specifically, the print properties have been characterized as a function of print temperature and print speed. In the case of single road width wall (SRWW) PLA prints, the total crystalline fraction increases due to the broadening of the crystallization window at higher print temperatures and lower print speeds. The results are substantiated by the constitutive modeling results that account for the effects of quiescent crystallization. However, SRWW PP prints display a reduction in the interlayer properties with temperature likely due to significant flow-induced crystallization effects, as suggested by the model. Interestingly, in the case of multilayer PP prints, the repeated heating/cooling cycles encountered during printing counteracts the flow-induced effects leading to an increase in mechanical properties with print temperature consistent with SRWW PLA prints.
The effects of the Soret and slip boundary conditions on thermosolutal convection with a Navier–Stokes–Voigt fluid
Authors: Badday Alaa Jabbar , Harfash Akil J.
Published: December 2022

In this paper, we study the problem of thermosolutal convection in a Navier–Stokes–Voigt fluid when the layer is heated from below and simultaneously salted from above or below. This problem is studied under the effects of Soret and slip boundary conditions. Both linear and nonlinear stability analyses are employed. When the layer is heated from below and salted from above, the boundaries exhibit great concordance, resulting in a very narrow region of probable subcritical instabilities. This proves that linear analysis is reliable enough to forecast the beginning of convective motion. The Chebyshev collocation technique and QZ algorithm have been used to solve systems of linear and nonlinear theories. For thermal convection in a dissolved salt field with a complex viscoelastic fluid of the Navier–Stokes–Voigt type, instability boundaries are computed. When the convection is of the oscillatory type, the Kelvin–Voigt parameter is observed to play a crucial role in functioning as a stabilizing agent. This effect's quantitative size is shown.
Boost ionic selectivity by coating bullet-shaped nanochannels with dense polyelectrolyte brushes
Authors: Karimzadeh Mohammad , Khatibi Mahdi , Ashrafizadeh Seyed Nezameddin
Published: December 2022

The influence of channel geometry on the ionic selectivity and ionic current rectification of soft nanochannels was numerically investigated. The nanochannels coated with polyelectrolyte layers (PELs) are termed as soft nanochannels. The asymmetric category of nanochannels, i.e., bullet-shaped, was considered in this study. When PEL is dense, the ionic partitioning effect cannot be ignored. To this end, through adopting a numerical approach using the finite element method, Poisson–Nernst–Planck and Navier–Stokes equations were solved at steady-state conditions by considering different values of permittivity, diffusivity, and dynamic viscosity for the PEL and the electrolyte. The results show that the PEL–electrolyte property difference leads to a significant improvement of the rectification behavior, especially at low and moderate salt concentrations. This not only highlights the importance of considering different properties for the PEL and the electrolyte but also implies that the rectification behavior of soft nanochannels/nanopores may be improved considerably by utilizing denser PELs. Considering a charge density of 80 mol/m3 and a bulk concentration of 20 mM, we demonstrate that the rectification factors for the bullet nanochannels, from 3.35 by ignoring the ion partitioning effect, can reach the values of 4.88 by considering the ion partitioning effect, respectively.
Effect of internal solitary wave on the dynamic response of a flexible riser
Authors: Duan Jinlong , Wang Xu , Zhou Jifu , You Yunxiang
Published: December 2022

Dynamic responses can arise when a flexible riser encounters the internal solitary wave (ISW) in the ocean. It is, thus, necessary to explore its dynamical behaviors induced by ISW. First, the governing equations of the flexible riser, ISW, and hydrodynamic force are introduced and interpreted. The accordant validations are performed so as to examine the accuracy of the applied models. Then, the dynamic response of the flexible riser is studied with the increase of the nondimensional ISW amplitude. Representative characteristics, such as vortex-induced vibration (VIV), top tension, and stress along the flexible riser, are mainly analyzed and discussed. The results prove that with the propagation of ISW, VIV in both inline (IL) and crossflow (CF) directions can be incurred. The maximum values of IL and CF oscillation frequencies, top tension, inline deflection, as well as riser stress can be detected while the ISW trough reaches to the flexible riser. Furthermore, all these four dynamic characteristics show an increasing trend with the increase of the nondimensional ISW amplitude. Note that the maximum values of oscillation frequencies, inline deflection, and stress on the upper section of the flexible riser tend to be larger compared with those on the lower section. In addition, the maximum inline deflection, top tension, and stress along the flexible riser can be affected by VIV responses.
Inducing SERS activity at graphitic carbon using graphene-covered Ag nanoparticle substrates: Spectroelectrochemical analysis of a redox-active adsorbed anthraquinone
Authors: Hatfield Kendrich O. , Putnam Seth T. , Rodríguez-López Joaquín
Published: December 2022

Graphitic carbon electrodes are central to many electrochemical energy storage and conversion technologies. Probing the behavior of molecular species at the electrochemical interfaces they form is paramount to understanding redox reaction mechanisms. Combining surface-enhanced Raman scattering (SERS) with electrochemical methods offers a powerful way to explore such mechanisms, but carbon itself is not a SERS activating substrate. Here, we report on a hybrid substrate consisting of single- or few-layer graphene sheets deposited over immobilized silver nanoparticles, which allows for simultaneous SERS and electrochemical investigation. To demonstrate the viability of our substrate, we adsorbed anthraquinone-2,6-disulfonate to graphene and studied its redox response simultaneously using SERS and cyclic voltammetry in acidic solutions. We identified spectral changes consistent with the reversible redox of the quinone/hydroquinone pair. The SERS intensities on bare silver and hybrid substrates were of the same order of magnitude, while no discernible signals were observed over bare graphene, confirming the SERS effect on adsorbed molecules. This work provides new prospects for exploring and understanding electrochemical processes in situ at graphitic carbon electrodes.
Effect of laser irradiation on a heavy crude oil sample: Changes in viscosity and implications for oil recovery and transport
Authors: Zhang Shanzhe , Sun Xiaorong , Yan Sining , Liu Cuiling , Miao Xinyang , Zhao Kun
Published: December 2022

High-viscosity oil has attracted people's attention as unconventional energy. Hence, the viscosity reduction played a significant role in pipeline transportation. In this paper, a 532 nm laser was employed to reduce the viscosity. Both voltage and temperature will change under laser irradiation due to the thermal effect. Moreover, the variation in the voltage and temperature was studied without laser irradiation in order to research the influence of laser irradiation on experimental results with different bias currents. An exponential function was used to fitted waveforms of falling voltage in order to study the effect of laser irradiation on liquid. The relationships among the voltage, temperature, and viscosity were also studied under laser irradiation. Particles in the crude oil absorbed energy from laser, which led to the liquid conductivity change. Due to laser irradiation, the temperature of the liquid will rise, resulting in the viscosity change. Laser technology will provide a distinctive driving force for the viscosity reduction.
Multi-point resistivity measurement system for full-diameter long cores during fluid displacement
Authors: Jia Jiang , Zhao Jun , Jiao Shixiang , Song Ruilin , Tang Tingke
Published: December 2022

Water injection is often used to improve oil and gas recovery in the late stage of oil and gas reservoir development. Studies show that this process leads to complex changes in reservoir resistivity and affects the evaluation of remaining oil and gas saturation in the reservoir. In this study, a multi-point resistivity measurement experimental system suitable for full-diameter rock samples during fluid displacement was designed to simulate and explore the distribution and variation of resistivity in the reservoir flooding process. In this regard, two columnar electrodes were installed on the end face of the core sample to serve as fluid injection and outflow channels. Moreover, five groups of nail-shaped electrodes arranged at equal intervals were embedded on the rubber sleeve of the core holder. The electrical bridge metering combined with seven electrodes was used to measure the resistivity and variation of six parts of the core sample during fluid displacement. A confining pressure was applied to the core sample to simulate the underground high-pressure environment and force the nail-shaped electrodes to cling to the sample to improve the accuracy of resistivity measurement. The simulated water flooding experiment was carried out with a sandstone sample from Tarim Oilfield in western China, and the distribution and variation of the sample’s resistivity were recorded. The experimental results conform to the laws of rock physics and confirm the reliability of the experimental system. The experimental system provides a guideline for determining the resistivity variation and evaluating the remaining oil and gas saturation of water-flooded reservoirs.
Mesoscopic perspectives on dynamic van der Waals theory for liquid–vapor phase transition
Authors: Huang Rongzong
Published: December 2022

We present a macroscopic dynamic van der Waals theory for liquid–vapor phase transition from mesoscopic perspectives offered by the kinetic model for multiphase fluids. We show that the excess effects stem from the unbalanced long-range molecular interaction in the inhomogeneous region, and, thus, only the excess internal (potential) energy but not the excess entropy is introduced. The excess internal energy is given as −12κρ∇·∇ρ rather than the canonical 12κ∇ρ·∇ρ, which leads to the same equilibrium state but different thermohydrodynamics. The present dynamic equations are identical to the macroscopic equations recovered by the kinetic model.
The African swine fever threat to Australia
Authors: Ward Michael P.
Published: December 2022

African swine fever (ASF) is not a new disease: its impact on domestic pig production in Africa was first documented 100 years ago. For most of the twentieth century ASF was considered a disease of Africa, with occasional incursions into Europe and the western hemisphere. However, during the past two decades, ASF has emerged as a truly global diseases, invading parts of Europe and spreading throughout Asia. By 2020, ASF had spread as far as Papua New Guinea. Why ASF has spread such distances so quickly is not well understood, however the movement of both live pigs and pork products undoubtedly is a major contributing factor. The role that wild pigs play in the spread and maintenance of ASF virus is a topic of ongoing debate. Adding to the complexity of the epidemiology of this disease, ASF virus can be transmitted by some tick species in particular ecosystems. Australia is vulnerable to an ASF virus incursion. The threat is further heightened by the uncertainty regarding whether our large and widely distributed feral pig population would become endemically infected, creating a barrier to eradication of the disease. Preventing an incursion of ASF virus relies on ongoing risk assessments based on where the virus currently exists, and the disease pathways for introduction. Within the Australian context, regulatory enforcement and surveillance of illegally important pork products is paramount to minimise the treat that ASF poses.
Electron-impact ionization of the 4p6 subshell in strontium
Authors: Borovik O
Published: December 2022

Electron-impact ionization of the 4p6 subshell in Sr atoms has been studied by observing the excitation dynamics of the electron spectra arising from the Auger decay of the 4p

5

n
l

n

′

l

′

states. The measurements were carried out in the energy range of incident electrons from the 4p6 ionization threshold at 26.92 to 600 eV. At near-threshold impact energies, the effect of post-collision interaction was found for most of the Auger lines. The identification of 21 lines observed between 10 and 14 eV electron energy showed that the 4p6 Auger spectrum of Sr atoms is completely described by the configurations 4p54d5s, 4p55s2 and 4p54d2. The cross sections for the lowest quartet and doublet states in 4p54d5s and 4p55s2 configurations have been obtained with the maximum values of (

3.5
±
0.5
)
×

10

−
18

cm2 at 52 eV for the (4p54d5s)4P

5

/

2

state and (

3.0
±
0.5
)
×

10

−
17

cm2 at 112 eV for the (4p55s2)2P

3

/

2

state. Configuration interaction and excitation-autoionization processes determine the energy behavior of the excitation cross sections of doublet states. The lower limit of the total ionization cross section of the 4p6 subshell in Sr has been obtained with the maximum value of (

6.2
±
1.2
)
×

10

−
17

cm2 at 92 eV.
Halo EFT for 31Ne in a spherical formalism
Authors: Elkamhawy Wael , Hammer Hans-Werner
Published: December 2022

We calculate the electromagnetic properties of the deformed one-neutron halo candidate 31Ne using Halo effective field theory (Halo EFT). In this framework, 31Ne is bound via a resonant P-wave interaction between the 30Ne core and the valence neutron. We set up a spherical formalism for 31Ne in order to calculate the electromagnetic form factors and the E1-breakup strength distribution into the 30Ne-neutron continuum at leading order in Halo EFT. The associated uncertainties are estimated according to our power counting. In particular, we assume that the deformation of the 30Ne core enters at next-to-leading order. It can be accounted for by including the J

P
= 2+ excited state of 30Ne as an explicit field in the effective Lagrangian.