bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive Shading System as a Building Heat Load Reduction
Authors: Masaryk Michal
Published: November 2022

This article deals with conceptual design and experimental implementation of active shading system to reduce building heat gains. First, the problem of building overheating in the summer period and the requirement of lighting in the building interior is explained. Then, the concept of the automated shading system is presented as an efficient yet simple solution to this problem. Along with that, the initial phase of experimental verification, namely the design and additives used, is described. In conclusion, the results of the initial phase are discussed and the future stages of the project along with its significance for the industry are explored.

Research background: The issue of overheating of utility buildings in the summer period and the requirement of sufficient lighting of their interior. Measurements in the respective literature and on-site in industrial buildings.

Purpose of the article: Explaining the conceptual design of an automated shading system as a remedy to the overheating problem and also to raise awareness of this widespread issue.

Methods: Direct measurements of the respective quantities in the industrial sites were conducted. Laboratory experiments along with measurements of several used shading solutions were conducted.

Findings & Value added: Some substances showed promising results in creating a translucent heat barrier for sunlight. Further solutions are planned to be tested.
COVID-19 and Perinatal Stress Experience – a Study Conducted as Part of the COVGEN Initiative
Authors: Kentschke Dominik , Bauer Ilena , Moser Julia , Schleger Franziska , Hahn Marlene , Pauluschke-Fröhlich Jan , Jakubowski Peter , Abele Harald , Preissl Hubert , Hartkopf Julia
Published: November 2022

Introduction During the COVID-19 pandemic, stress and anxiety in the population increased due to concerns about people’s own health and that of their relatives, as well as changes in
everyday life due to measures taken to reduce the infection rate. Pregnant women are particularly stressed. The present study examines how the COVID-19 pandemic affects the stress experience
and mental health of pregnant women and mothers of newborns and how care could be optimized.

Methods As part of the international COVGEN initiative (https://www.covgen.org) to investigate the effects of the COVID-19 pandemic on the
peripartum period, pregnant and postpartum women were asked about their experience with stress using the COPE-IS (Coronavirus Perinatal Experiences – Impact Survey) questionnaire developed
for this purpose and translated from the English. In addition, demographic data, pre-existing diseases, pregnancy complications and the care situation were recorded. The questionnaire was
either administered as hardcopy to inpatients at the Department of Women’s Health, University Hospital Tübingen, Germany, or online. All pregnant women and mothers who were pregnant or had
given birth after the official start of the COVID-19 pandemic (11 March 2020) were eligible to participate.

Results Complete data sets of n = 156 pregnant women and n = 221 postpartum women were available for evaluation. The general stress level assessed with the COPE-IS was significantly
increased by the COVID-19 pandemic in both, pregnant and postpartum women, with pre-existing conditions such as respiratory diseases and pregnancy-related diseases like gestational diabetes
adding to the stress. The subjectively perceived quality of care/support during pregnancy also influenced the stress level.

Conclusions Fears of a COVID-19 infection and changes in preventive and aftercare services were a burden for the women surveyed. Intensified care during pregnancy and puerperium
could help to stabilize the mental situation and reduce stress.
Weiterentwicklung und Vernetzung der onkologischen
Versorgungsstrukturen, der Qualitätssicherung und der
Forschung
Authors: Klinkhammer-Schalke Monika , Wesselmann Simone , Bruns Johannes , Nettekoven Gerd , Tillack Anett , Follmann Markus , Arndt Volker , Graeven Ullrich , Hartz Tobias , Illmer Thomas , Inwald Elisabeth C. , Kaiser Thomas , Nothacker Monika , Ortmann Olaf , Schmidt Sabine , Schmitt Jochen , Zeissig Sylke R. , Seufferlein Thomas
Published: November 2022

Wie ist eine bessere Vernetzung von Medizinischen Leitlinien, Implementierung,
Umsetzung und Messung des Outcomes in der onkologischer Versorgung
möglich – sowohl für Erkrankte als auch für
Leistungserbringer:innen ist Ziel der 2019 auf den Weg gebrachten
Querschnitts-Arbeitsgruppe „Qualität und Vernetzung“.
Der folgende Artikel gibt eine Übersicht über bisher erreichte
Ziele in Leitlinien-Entwicklung, Qualitätsindikatoren-Entwicklung und
Dokumentation in Krebsregistern.
BIOPASS-Hybrid-Navigation für die endoskopische Nasennebenhöhlenchirurgie – ein Assistenzsystem
Authors: Heuermann Katharina , Bieck Richard , Dietz Andreas , Fischer Miloš , Hofer Mathias , Neumuth Thomas , Pirlich Markus
Published: November 2022

Bisherige Navigationssysteme können zwar im Rahmen der funktionellen endoskopischen Nasennebenhöhlenchirurgie (FESS) die Position des „getrackten“ Operationsinstruments in radiologische Schnitt-Bilddaten bestimmen, geben aber keine Hilfestellung direkt im videoendoskopischen Bild des Operateurs. Diese direkte Hilfestellung zur intraoperativen Orientierung und Risikoreduzierung zu entwickeln, war Ziel des BIOPASS-Projekts (Bild Ontologie und prozessgestütztes Assistenzsystem). Das Projekt verfolgt die Entwicklung eines neuartigen, markerlosen Navigationssystems für die FESS. BIOPASS beschreibt ein Hybrid-System, das verschiedene Sensordaten integriert und dem Chirurgen zur Verfügung stellt. Ziel ist es, das Tracking zu verlassen und ausschließlich Navigationsinformation direkt im Videobild zur Verfügung zu stellen. Die vorliegende Arbeit beschreibt den ersten Schritt der Entwicklung, im Rahmen dessen die Operationsphasen (Workflows) untersucht, die videoendoskopischen Landmarken klassifiziert und eine erste klinische Evaluation der Modellversion durchgeführt wurden. Die Ergebnisse stellen eine wichtige Grundlage und Plattform für den nächsten Projektschritt dar.
Die Schnittstelle der Logopädie im Prozess der Geschlechtsangleichung von Mann zu Frau
Authors: Heydrich Kyra , Rustemeier-Holtwick Annette , Latoszek Ben Barsties v.
Published: November 2022

Hintergrund Die Stimme ist für die Geschlechtsidentifikation während des Transitionsprozesses entscheidend, da die Stimmfeminisierung einen bedeutenden Anteil zum Gelingen des Passing hat. Um die Rolle der Logopädie während des interdisziplinären Geschlechtsangleichungsprozesses von MzF-Trans* einordnen zu können, bedarf es möglicher Handlungsempfehlungen für die Zusammenarbeit mit den beteiligten Ärzten.

Material und Methoden Vier Experteninterviews aus den Bereichen der Phonochirurgie, Phoniatrie, Endokrinologie sowie plastischen Chirurgie wurden durchgeführt. Auf Grundlage dieser Interviews wurde ein potenzieller Leitlinienkonsens zur Einordnung der Rolle der Logopädie im Prozess der Geschlechtsangleichung von MzF-Trans* erstellt.

Ergebnisse Anhand der Expertengespräche wird einheitlich empfohlen, die logopädische Stimmtherapie schon zu Beginn der Transition zu berücksichtigen. Primär sollte eine konservative Therapie berücksichtigt werden, um z.B. irreversible Operationen des Larynx zu vermeiden. Der Fokus logopädischer Stimmtherapie bei Stimmfeminisierung obliegt zentral bei der Anpassung der mittleren Sprechstimmlage. In postoperativen Fällen sollte die logopädische Stimmtherapie das Sprechverhalten an die neue Anatomie anpassen und Komplikationen, wie z.B. eine unökonomische Stimm- und Sprechgebung, vorbeugen.

Schlussfolgerung Die aktuellen Interviews stellen einen ersten Einblick in die Kooperation von Logopäden und den medizinischen Fachbereichen zur Behandlung von MzF-Trans* dar. Um die Empfehlungen aus den Experteninterviews für einen potenziellen Leitlinienkonsens implementieren zu können, bedarf es Rücksprachen mit den hierzu beteiligten Fachgesellschaften sowie mehr randomisierter Studien zu spezifischen logopädischen Stimmtherapien.
Middle-distance Front Crawl Determinants When Using a
Wetsuit
Authors: Gay Ana , Ruiz-Navarro Jesús J. , Cuenca-Fernández Francisco , López-Belmonte Óscar , Fernandes Ricardo J. , Arellano Raúl
Published: November 2022

Our aim was to establish the determinants explaining the wetsuit advantages in
middle-distance swimming efforts. Thirty-one triathletes and open water swimmers
performed two 400 m front crawl bouts in a 25 m swimming pool
with swim and wetsuits (with 48 h rest in-between). Anthropometric,
kinematic and physiological variables were measured and Pearson correlation
coefficients and stepwise linear regression analysis were used to determine
their relationships. Associations observed in the 400 m front crawl
included time improved using wetsuit with swimmers age (r=0.38;
p=0.017), cross-sectional area (r=0.33;
p=0.034), wetsuit upper limbs thickness (r=–0.49;
p=0.010), ΔInternational Swimming Federation Points
(r=–0.39;p=0.016), Δstroke rate (SR,
r=0.48; p=0.003), Δstroke length (SL,
r=-0.39; p=0.015), Δpropelling efficiency
(r=–0.37; p=0.019) and Δblood lactate
concentrations (r=0.30; p=0.048) in the total sample. In
females, associations were found between the time improved and wetsuit upper and
lower limbs thickness (both r=–0.78; p=0.011),
and in males associations were found between time improved and age
(r=0.43; p=0.030), ΔSR (r=0.56;
p=0.005) and ΔSL (r=–0.44;
p=0.026). Furthermore, 48% of the 400 m front crawl
time improved was explained by wetsuit upper limbs thickness and SR changes
(total sample), 62% explained by the wetsuit lower limbs thickness
(females) and 48% of this enhancement was related to age and SR changes
(males). Therefore, faster upper and lower limbs actions and wetsuit upper and
lower limbs thickness are beneficial for 400 m front crawl performance
improvement.
Endoscopic full-thickness resection (EFTR) compared to submucosal tunnel endoscopic resection (STER) for treatment of gastric gastrointestinal stromal tumors
Authors: Chiu Philip Wai Yan , Yip Hon Chi , Chan Shannon Melissa , Ng Stephen Ka Kei , Teoh Anthony Yuen Bun , Ng Enders Kwok Wai
Published: November 2022

Background and study aims Submucosal tunnel endoscopic resection (STER) is being increasingly performed for treatment of gastric gastrointestinal stromal tumor (GIST), while STER has been limited by close dissection within tunnel and risking breach of tumor capsule. Endoscopic full-thickness resection (EFTR) allows resection of GIST with margins to prevent recurrence. This study aimed to compare EFTR against STER for treatment of gastric GIST.

Patients and methods We retrospectively reviewed clinical outcomes of patients with gastric GIST who received either STER or EFTR. Patients with gastric GISTs < than 4 cm were included. Clinical outcomes including baseline demographics, perioperative and oncological outcomes were compared between the two groups.

Results From 2013 to 2019, 46 patients with gastric GISTs were treated with endoscopic resection, 26 received EFTR and 20 received STER. Most of the GISTs were in the proximal stomach. There was no difference in operative time (94.9 vs 84.9 mins; P = 0.401), while endoscopic suturing was applied more for closure after EFTR (P < 0.0001). Patients after STER had earlier resumption of diet and shorter hospital stay while there was no difference in adverse event rate between two groups. The en-bloc resection rate for EFTR was significantly higher than for STER (100 % vs 80 %; P = 0.029), while there was no difference in the local recurrence.

Conclusions This study demonstrated that although patients who received EFTR had longer hospital stays and slower resumption of diet compared to those who underwent STER, EFTR achieved a significantly higher rate of en-bloc resection compared to STER for treatment of gastric GIST.
One-Step, Gram-Scale Synthesis of Caffeine-d
9 from Xanthine and CD3I
Authors: Gris Pavel , Murphy Graham K. , Tarasca Michael V. , Tomlinson Cassidy J.
Published: November 2022

A one-step, gram-scale synthesis of caffeine-d
9 was achieved using xanthine and CD3I. The reaction proceeds at room temperature using dimsyl sodium as base and THF as solvent, and conducting the reaction on a 1-g scale gave caffeine and caffeine-d
9 in 77% and 86% yield, respectively, after recrystallization.
N-(Trimethylsilyl)-2-amino-5-nitrothiazole: An Efficient Reagent for the Direct Synthesis of 2-Amino-5-nitrothiazole-Based Antimicrobial Agents
Authors: Livinghouse Tom , Koenig Heidi N. , Demeritte Amethyst R. , Nelson Genevieve P.
Published: November 2022

Here we report the synthesis of a novel reagent designed to prepare 2-amino-5-nitrothiazole (ANT) amides and analogues in high yields. N-(Trimethylsilyl)-2-amino-5-nitrothiazole (N-(TMS)-ANT) was prepared in 99% yield via silylation of ANT using 1,1,1,3,3,3-hexamethyldisilazane (HMDS), trimethylsilyl chloride (TMSCl), and catalytic saccharin. N-(TMS)-ANT is a superb reagent for the preparation of ANT amides in excellent yields. Notably, cyclic anhydrides and base-sensitive acyl chlorides can be utilized with N-(TMS)-ANT to furnish ANT amides that are difficult to prepare by previously reported procedures.
Recyclable Palladium-Catalyzed Carbonylative Cyclization of Aryl Iodides and 2-Hydroxyacetophenones towards Flavones
Authors: Cai Mingzhong , Huang Bin , Xie Gang , Zhan Jianan
Published: November 2022

A highly efficient heterogeneous palladium-catalyzed carbonylative cyclization of aryl iodides and 2-hydroxyacetophenones is developed. The reaction proceeds efficiently in DMSO at 120 °C under 3 bar of carbon monoxide by using 2 mol% of an MCM-41-immobilized bidentate phosphine palladium complex [MCM-41-2P-Pd(OAc)2] as the catalyst and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base, providing a general, efficient and practical approach for the assembly of a wide variety of flavones in mostly good to high yields from readily available starting materials. This supported palladium catalyst can be easily recovered via centrifugation of the reaction mixture and recycled more than nine times without any significant loss of its catalytic efficiency.
Discourse features of an Ethiopian health radio phone-in
Authors: Adal Jemal Mohammed
Published: November 2022

This study aims to describe the discourse features of an Ethiopian health radio phone-in program. More specifically, building on previous studies that draw on the methodological insights of CA/MCA, we demonstrate how topical discussion about public health issues on a radio phone-in show is accomplished. Our analysis is based on eight hours of recorded and transcribed talk data from a public FM radio station broadcasting in Amharic, FM Addis 97.1. Our analysis shows that the speech exchange between the host and callers is central to the organization of interactions in the talk show and comprises phases such as openings, topical talk, and closings. We further demonstrate using examples how what counts as ‘topical talk’ is initiated and pursued through reliance on a sequential development of relevant categories and identities, where one builds upon another during the course of the interaction. Our analysis reveals that interaction resources such as reminding callers of the theme/topic, posing a question relating to the theme of the talk, and using ‘eshi’ (which translates as ‘ok’) or ‘eshi’ prefaced statements or questions are employed to initiate topical talk as well as elicit callers’ membership categories vis-à-vis the theme. Such categorical information is in turn drawn upon to develop topical talk. Central to the development of topical talk in the program then is the elicitation of callers’ first-hand experiential accounts. Overall, we illustrate that the accomplishment of the topical talk involves a reflexive combination of categorical and sequential methods through which layers of background context are built and drawn upon by the participants in the talk show.
Sharp hierarchical upper bounds on the critical two-point function for long-range percolation on Zd
Authors: Hutchcroft Tom
Published: November 2022

Consider long-range Bernoulli percolation on Zd in which we connect each pair of distinct points x and y by an edge with probability 1 − exp(−β‖x − y‖−d−α), where α > 0 is fixed and β ⩾ 0 is a parameter. We prove that if 0 < α < d, then the critical two-point function satisfies 1|Λr|∑x∈ΛrPβc(0↔x)⪯r−d+α for every r ⩾ 1, where Λr=[−r,r]d∩Zd. In other words, the critical two-point function on Zd is always bounded above on average by the critical two-point function on the hierarchical lattice. This upper bound is believed to be sharp for values of α strictly below the crossover value αc(d), where the values of several critical exponents for long-range percolation on Zd and the hierarchical lattice are believed to be equal.
An automated fast neutron computed tomography instrument with on-line focusing for non-destructive evaluation
Authors: Bisbee M. G. , Oksuz I. , VanZile M. P. , Cherepy N. J. , Cao L. R.
Published: November 2022

A fast neutron tomography imaging instrument has been designed, built, and tested at The Ohio State University 500 kW Research Reactor on a fast neutron beamline with a peak neutron flux ≈5.4 × 107 n·cm−2·s−1 at 1.6 MeV median neutron energy. The instrument and beamline are also configurable for thermal neutron imaging. The imaging apparatus is composed of a lens coupled, water-cooled Electron Multiplying Charge Coupled Device camera, a front-surface mirror, and a high light yield plastic Polyvinyl toluene scintillator. The instrument sits on a mobile cart. A total of 5 motion-control stages are built into the system for XYZ and rotational degrees of freedom for sample positioning; the fifth stage fine tunes the focal distance between the camera and the scintillator to achieve on-line focusing. A Python code with a user-friendly graphical user interface controls the fully automated image acquisition, not requiring user interaction, yet facilitating tracking of the image acquisition. A complete fast neutron computed tomography dataset with 360 projections requires less than 3 h, with 30 s per projection. On-line focusing is accomplished with a commercial, off-the-shelf, dielectrically actuated liquid lens. Finally, tomographic reconstructions are visualized using the Livermore Tomography Tools software package. The effective pixel size (width and height) is ≈0.1058 mm, yielding a minimum voxel size of 0.1058 × 0.1058 × 0.1058 mm3, and produces a spatial resolution of 231 μm when calculated from knife-edge measurements.
Gaussian (p,q)-Jacobsthal and Gaussian (p,q)-Jacobsthal Lucas numbers and their some interesting properties
Authors: Saba N. , Boussayoud A.
Published: November 2022

In the present article, we introduce two new notions, which are called Gaussian (p, q)-Jacobsthal numbers sequence GJp,q,nn=0∞ and Gaussian (p, q)-Jacobsthal Lucas numbers sequence Gjp,q,nn=0∞, and we present and prove our exciting properties and results, which relate these sequences. We first give recurrence relations, Binet’s formulas, explicit formulas, and negative extensions of them. We then obtain some important identities for Gaussian (p, q)-Jacobsthal and Gaussian (p, q)-Jacobsthal Lucas numbers and some connection formulas between these Gaussian numbers. After that, we give some summation formulas and the symmetric functions of Gaussian (p, q)-Jacobsthal and Gaussian (p, q)-Jacobsthal Lucas numbers. In addition, by using the symmetric functions, we derive a new class of generating functions for Gaussian (p, q)-Jacobsthal and Gaussian (p, q)-Jacobsthal Lucas numbers.
Advanced technique for measuring relative length changes under control of temperature and helium-gas pressure
Authors: Agarmani Y. , Hartmann S. , Zimmermann J. , Gati E. , Delleske C. , Tutsch U. , Wolf B. , Lang M.
Published: November 2022

We report the realization of an advanced technique for measuring relative length changes ΔL/L of mm-sized samples under the control of temperature (T) and helium-gas pressure (P). The system, which is an extension of the apparatus described in the work of Manna et al. [Rev. Sci. Instrum. 83, 085111 (2012)], consists of two 4He-bath cryostats, each of which houses a pressure cell and a capacitive dilatometer. The interconnection of the pressure cells, the temperature of which can be controlled individually, opens up various modes of operation to perform measurements of ΔL/L under the variation of temperature and pressure. Special features of this apparatus include the possibility (1) to increase the pressure to values far in excess of the external pressure reservoir, (2) to substantially improve the pressure stability during temperature sweeps, (3) to enable continuous pressure sweeps with both decreasing and increasing pressure, and (4) to simultaneously measure the dielectric constant of the pressure-transmitting medium, viz., helium, εrHe(T,P), along the same T-P trajectory as that used for taking the ΔL(T, P)/L data. The performance of the setup is demonstrated by measurements of relative length changes (ΔL/L)T at T = 180 K of single crystalline NaCl upon continuously varying the pressure in the range 6 ≤ P ≤ 40 MPa.
Substrate conformal imprint fabrication process of synthetic antiferromagnetic nanoplatelets
Authors: Li J. , van Nieuwkerk P. , Verschuuren M. A. , Koopmans B. , Lavrijsen R.
Published: November 2022

Methods to fabricate and characterize monodisperse magnetic nanoplatelets for fluid/bio-based applications based on spintronic thin-film principles are a challenge. This is due to the required top-down approach where the transfer of optimized blanket films to free particles in a fluid while preserving the magnetic properties is an uncharted field. Here, we explore the use of substrate conformal imprint lithography (SCIL) as a fast and cost-effective fabrication route. We analyze the size distribution of nominal 1.8 μm and 120 nm diameter platelets and show the effect of the fabrication steps on the magnetic properties which we explain through changes in the dominant magnetization reversal mechanism as the size decreases. We show that SCIL allows for efficient large-scale platelet fabrication and discuss how application-specific requirements can be solved via process and material engineering.
Net emission coefficient for two-dimensional HID light source
Authors: Ghrib Basma , Bouaoun Mohamed , Elloumi Hatem
Published: November 2022

Net emission coefficients were calculated for a two-dimensional HID light source in accordance with the composition, the local temperature, and the radiation relative to the rest of the discharge which can be absorbed in the same volume of an element. All important line-broadening mechanisms were included, and the effects of emission and absorption on the net emission coefficient were accounted for on a line-by-line basis. Particular attention has been paid to the effect of pressure on the net emission of the 253.7 nm resonance line and the visible lines.
Quasi-longitudinal propagation of nonlinear whistlers with steep electrostatic fluctuations
Authors: Barsagade Gayatri , Sharma D.
Published: November 2022

The quasi-longitudinal whistlers are recently reported in magnetized laboratory plasmas, i.e., at densities considerably higher than the space or magnetospheric plasmas. Given their oblique nature, these whistlers are known to be accompanied by density perturbations which undergo strong nonlinear steepening exclusively for their propagation close to resonant cone angle [Yoon et al., J. Geophys. Res. 119, 1851 (2014)]. This aspect is examined in the parameter regime of laboratory experiments where quasi-longitudinal whistler fluctuations are reported. A systematic study by a set of dedicated single mode numerical solution of the fully nonlinear model of quasi-longitudinally propagating whistlers is presented predominantly covering the high-density (low magnetic field) regime relevant to the laboratory whistler experiments. Following the recovery of existing computational results available for low-density cases, the computations in the newer regime are performed in the present study. The evolution recovered in both these regimes finds the sharp density structures or oscillations to be of resonant origin. While structures accompanying the whistlers' low-density resonant cone readily agree with the upper hybrid resonance frequency, the freshly covered high-density regime shows that the strong nonlinear nature of the whistler is capable of producing a modification in the resonant frequency, causing it to downshift from its linearly expected upper hybrid frequency.
Effect of Mg-doping and Fe-doping in lead zirconate titanate (PZT) thin films on electrical reliability
Authors: Koh Dongjoo , Ko Song Won , Yang Jung In , Akkopru-Akgun Betul , Trolier-McKinstry Susan
Published: November 2022

Uniformly acceptor doped Pb(Zr0.48Ti0.52)O3 (PZT) films with 2 mol. % Mg or Fe prepared by chemical solution deposition exhibited decreased dielectric constants and remanent polarizations relative to undoped PZT. For highly accelerated lifetime testing (HALT) at 200 °C and an electric field of 300 kV/cm in the field up direction, the HALT lifetimes (t50) for undoped, Mg-doped, and Fe-doped PZT films were shortened from 2.81 ± 0.1 to 0.21 ± 0.1 and 0.54 ± 0.04 h, respectively. Through thermally stimulated depolarization current measurement, significant VO∙∙ electromigration was found in homogeneously Mg-doped PZT thin films, a major factor in their short HALT lifetime. Because the concentration of oxygen vacancies increases with uniform acceptor doping, the lifetime decreases. In contrast, when a thin layer of Mg-doped or Fe-doped PZT was deposited on undoped PZT or Nb-doped PZT (PNZT), the HALT lifetimes were longer than those of pure PZT or PNZT films. This confirms prior work on PNZT films with a Mn-doped top layer, demonstrating that the HALT lifetime increases for composite films when a layer with multivalent acceptors is present near the negative electrode during HALT. In that case, the compensating electrons are trapped, presumably on the multivalent acceptors, thus increasing the lifetime.
Exploring bifurcations in Bose–Einstein condensates via phase field crystal models
Authors: Steinberg A. B. , Maucher F. , Gurevich S. V. , Thiele U.
Published: November 2022

To facilitate the analysis of pattern formation and the related phase transitions in Bose–Einstein condensates, we present an explicit approximate mapping from the nonlocal Gross–Pitaevskii equation with cubic nonlinearity to a phase field crystal (PFC) model. This approximation is valid close to the superfluid–supersolid phase transition boundary. The simplified PFC model permits the exploration of bifurcations and phase transitions via numerical path continuation employing standard software. While revealing the detailed structure of the bifurcations present in the system, we demonstrate the existence of localized states in the PFC approximation. Finally, we discuss how higher-order nonlinearities change the structure of the bifurcation diagram representing the transitions found in the system.
Receiver circuit improvement of dual frequency-comb ka-band Doppler backscattering system in the large helical device (LHD)
Authors: Nasu T. , Tokuzawa T. , Tsujimura T. I. , Ida K. , Yoshinuma M. , Kobayashi T. , Tanaka K. , Emoto M. , Inagaki S. , Ejiri A. , Kohagura J.
Published: November 2022

Doppler-backscattering (DBS) has been used in several fusion plasma devices because it can measure the perpendicular velocity of electron density perturbation v⊥, the radial electric field Er, and the perpendicular wavenumber spectrum S(k⊥) with high wavenumber and spatial resolution. In particular, recently constructed frequency comb DBS systems enable observation of turbulent phenomena at multiple observation points in the radial direction. A dual-comb microwave DBS system has been developed for the large helical device plasma measurement. Since it is desirable to control the gain of each frequency-comb separately, a frequency-comb DBS system was developed with a function to adjust the gain of the scattered signal intensity of each channel separately. A correction processing method was also developed to correct the amplitude ratio and the phase difference between the in-phase and quadrature-phase signals of the scattered signals. As a result, the error in Doppler-shift estimation required to observe vertical velocity and the radial electric field was reduced, which enables more precise measurements.
Long-time asymptotic behavior of the coupled dispersive AB system in low regularity spaces
Authors: Zhu Jin-Yan , Chen Yong
Published: November 2022

In this paper, we mainly investigate the long-time asymptotic behavior of the solution for coupled dispersive AB systems with weighted Sobolev initial data, which allows soliton solutions via the Dbar steepest descent method. Based on the spectral analysis of Lax pairs, the Cauchy problem of coupled dispersive AB systems is transformed into a Riemann–Hilbert problem, and the existence and uniqueness of its solution is proved by the vanishing lemma. The stationary phase points play an important role in determining the long-time asymptotic behavior of these solutions. We demonstrate that in any fixed time cone Cx1,x2,v1,v2=(x,t)∈R2∣x=x0+vt,x0∈x1,x2,v∈v1,v2, the long-time asymptotic behavior of the solution for coupled dispersive AB systems can be expressed by N(I) solitons on the discrete spectrum, the leading order term O(t−1/2) on the continuous spectrum, and the allowable residual O(t−3/4).
Spreading of droplets under various gravitational accelerations
Authors: D’Angelo Olfa , Kuthe Felix , van Nieuwland Kasper , Ederveen Janssen Clint , Voigtmann Thomas , Jalaal Maziyar
Published: November 2022

We describe a setup to perform systematic studies on the spreading of droplets of complex fluids under microgravity conditions. Tweaking the gravitational acceleration under which droplets are deposited provides access to different regimes of the spreading dynamics, as quantified through the Bond number. In particular, microgravity allows us to form large droplets while remaining in the regime where surface tension effects and internal driving stresses are predominant over hydrostatic forces. The vip-drop2 (visco-plastic droplets on the drop tower) experimental module provides a versatile platform to study a wide range of complex fluids through the deposition of axisymmetric droplets. The module offers the possibility to deposit droplets on a precursor layer, which can be composed of the same or a different fluid. Furthermore, it allows us to deposit four droplets simultaneously while conducting shadowgraphy on all of them and observing either the flow field (through particle image velocimetry) or the stress distribution inside the droplet in the case of stress birefringent fluids. It was developed for a drop tower catapult system, is designed to withstand a vertical acceleration of up to 30 times the Earth’s gravitational acceleration in the downward direction, and is capable of operating remotely under microgravity conditions. We provide a detailed description of the module and an exemplary data analysis for droplets spreading on-ground and in microgravity.
Manipulation of ferroelectric domain inversion and growth by optically induced 3D thermoelectric field in lithium niobate
Authors: Wang Xiaoliang , Cao Qiang , Wang Ruonan , Cao Xiangdong , Liu Sheng
Published: November 2022

We experimentally demonstrate the use of a femtosecond laser-induced thermoelectric field to manipulate remotely—not only at the focal spot—the inversion and growth of ferroelectric domain in lithium niobate. The process involves two steps: the first step is laser marking, in which a laser is used to mark the origin of the desired domain inversion. The second step is laser induction, in which a laser-induced thermoelectric field is used to invert the domain at the marker site and drive domain growth. The induced thermoelectric field is distributed in three dimensions, which can simultaneously manipulate the domain inversion and growth length of multiple marked sites within a diameter of ∼200 μm. The length of domain growth is synergistically controlled by the position and intensity of marking and induction, which can exceed 100 μm. This two-step poling method greatly improves the efficiency of all-optical poling and provides a different suite of tools for tailoring ferroelectric domains.
Dynamic characteristics of moving droplets impacting sessile droplets with different Reynolds numbers
Authors: Chen Desheng , Wang Tingting , Ming Lining , Qiu Man , Lin Zhe
Published: November 2022

The collision of moving droplets with sessile droplets is a common occurrence in fields of industry, including power generation, chemical engineering, and aerospace, among others. In this paper, the collision of propylene glycol, glycerol, and de-ionized water droplets is studied for given collision speeds and different volume ratios of moving and sessile droplets using high-speed photography. It is found that droplet collision at a speed of about 0.25 m/s leads to compression deformation, whereas collision at about 1.10 m/s typically produces features, such as a non-splashing liquid crown and a central liquid jet. In this paper, the main characteristics of the above phenomena are quantified, the influence of the Reynolds number at different volume ratios is studied, and the main phenomena are explained from the perspective of an energy analysis. The findings reported here are significant for the solution of practical engineering problems and improving the stability of equipment operation.
Atomic-scale investigation on the origin of in-plane variants in L1-FePt nanoparticles embedded in a single-crystalline MgO matrix
Authors: Wu K. , Fu X. , Zhu W. , Huang X.
Published: November 2022

In this work, we present an atomic-scale investigation of L10-FePt particles that are partly or fully embedded in a single-crystalline MgO matrix. Hundreds of particles in different orientations, of different sizes, and with different side contact facets are statistically and quantitatively analyzed. It is found that the presence of side contact facets does not introduce any misorientation in particles with the c axis out-of-plane (OP), even in those of small sizes. In addition, a markedly higher proportion of in-plane (IP) variants is found in smaller particles of sizes less than 10 nm, and most IP variants and the IP part in multi-variants have a large area of side contact facets or are even fully embedded. Those results can be explained by the fact that the transformation strain and interface strain jointly affect the particle orientation, and the competition between total strain energy in the film plane and in lateral planes plays a key role in determining particle orientation. Thus, a suggestion on the L10-FePt nanoparticle film production can be proposed that a moderate area of side contact facets may help keep a perfect OP orientation in the OP particles without increasing the proportion of IP variants. Additionally, our work can provide reference information on the variant orientation preference during a post-annealing process in nanoparticle films on a rough substrate or embedded in a matrix as well as in core–shell material systems.
Localized dynamics arising from multiple flat bands in a decorated photonic Lieb lattice
Authors: Hanafi Haissam , Menz Philip , McWilliam Allan , Imbrock Jörg , Denz Cornelia
Published: November 2022

Photonic lattices have emerged as an ideal testbed for localizing light in space. Among others, the most promising approach is based on flat band systems and their related nondiffracting compact localized states. So far, only compact localized states arising from a single flat band have been found. Such states typically appear static, thus not allowing adaptive or evolutionary features of light localization. Here, we report on the first experimental realization of an oscillating compact localized state arising from multiple flat bands. We observe an oscillatory intensity beating during propagation in a two-dimensional photonic decorated Lieb lattice. The photonic system is realized by direct femtosecond laser writing and hosts most importantly multiple flat bands at different eigenenergies in its band structure. Our results open new avenues for evolution dynamics in the up to now static phenomenon of light localization in periodic waveguide structures and extend the current understanding of light localization in flat band systems.
Effect of electromigration dispersion and non-Newtonian rheology of a charged solute in a microcapillary
Authors: Chatterjee A. , Nayak A. K. , Weigand B.
Published: November 2022

The present work is concerned with the electromigration interaction of non-Newtonian fluid in a rectangular micro-capillary under the influence of an external electric field to predict the spatiotemporal dynamics of the solute concentration due to an effective dispersion and migration velocity. The solute concentration is optimized by dispersion and a driving force exploiting the interplay between the sequential ionic distribution and the local electrical conductivity coupled with the characteristics of the fluid. The incompressible Navier–Stokes equation combined with the Poisson equation for the electric field is considered for the flow transport incorporated with the Nernst–Planck equation for the ion transport. The numerical computations are performed for the coupled electro-osmosis/electrophoresis migrated nonlinear equations by a control volume approach for effective dispersion. The analytical observation of electrical conductivity in the case of a planar uniformly charged substrate is found to be varied locally near the sample peak and majorly concentration dependent. The asymptotic analysis for the velocity is made by using the lubrication approximation. The solutal species calculation is made from an area averaged nonlinear advection diffusion equation incorporating the coupled momentum equation. It is observed that the Taylor–Aries dispersion effect is dependent on the flow behavior index of the power law fluid, the flow strength, and the local sample concentration. The study of the time regime and the flow strength dependent instantaneous dispersion has also been conducted.
Tip-scan high-speed atomic force microscopy with a uniaxial substrate stretching device for studying dynamics of biomolecules under mechanical stress
Authors: Chan Feng-Yueh , Kurosaki Ryo , Ganser Christian , Takeda Tetsuya , Uchihashi Takayuki
Published: November 2022

High-speed atomic force microscopy (HS-AFM) is a powerful tool for studying the dynamics of biomolecules in vitro because of its high temporal and spatial resolution. However, multi-functionalization, such as combination with complementary measurement methods, environment control, and large-scale mechanical manipulation of samples, is still a complex endeavor due to the inherent design and the compact sample scanning stage. Emerging tip-scan HS-AFM overcame this design hindrance and opened a door for additional functionalities. In this study, we designed a motor-driven stretching device to manipulate elastic substrates for HS-AFM imaging of biomolecules under controllable mechanical stimulation. To demonstrate the applicability of the substrate stretching device, we observed a microtubule buckling by straining the substrate and actin filaments linked by α-actinin on a curved surface. In addition, a BAR domain protein BIN1 that senses substrate curvature was observed while dynamically controlling the surface curvature. Our results clearly prove that large-scale mechanical manipulation can be coupled with nanometer-scale imaging to observe biophysical effects otherwise obscured.
Cryogenic mirror position actuator for spectroscopic applications
Authors: Słowiński Michał , Makowski Marcin , Sołtys Kamil Leon , Stankiewicz Kamil , Wójtewicz Szymon , Lisak Daniel , Piwiński Mariusz , Wcisło Piotr
Published: November 2022

We demonstrate a mirror position actuator that operates in a wide temperature range from room temperature to a deep cryogenic regime (10 K). We use a Michelson interferometer to measure the actuator tuning range (and piezoelectric efficiency) in the full temperature range. We demonstrate an unprecedented range of tunability of the mirror position in the cryogenic regime (over 22 μm at 10 K). The capability of controlling the mirror position in the range from few to few tens of microns is crucial for cavity-enhanced molecular spectroscopy techniques, especially in the important mid-infrared spectral regime where the length of an optical cavity has to be tunable in a range larger than the laser wavelength. The piezoelectric actuator offering this range of tunability in the cryogenic conditions, on the one hand, will enable development of optical cavities operating at low temperatures that are crucial for spectroscopy of large molecules whose dense spectra are difficult to resolve at room temperature. On the other hand, this will enable us to increase the accuracy of the measurement of simple molecules aimed at fundamental studies.
Convective instabilities in the Czochralski model with different radii ratios
Authors: Liu Yong , Zhang Liangqi , Liu Hao , Yin Linmao , Xiao Yao , Wang Yue , Zeng Zhong
Published: November 2022

In this work, we explore the instability of the complex convection in the Czochralski model concerning the effects of the radii ratio, melt materials, and crystal rotation. Particularly, linear stability analysis is conducted based on the spectral element method for three groups of cases with the same interval for the variation of the radii ratio (Λ) but different material Prandtl number (Pr) and dimensionless crystal rotation velocity ωs. We observe that, for both ωs = 0 and ωs = 300, the mixed convection of silicon melt (Pr = 0.011) becomes less stable with the increase in radii ratio and the instability is of purely inertial mechanism. In contrast, as for the LiCaAlF6 melt (Pr = 1.4), a larger radii ratio would improve the stability and the instability is dominated by buoyancy mechanism for ωs = 300. Moreover, two times of critical wavenumber transitions occur in the critical stability curve for silicon melt (Pr = 0.011). Each transition associates with a convex turning point of the critical stability curve for ωs = 0, while only one turning point remains when ωs shifts to 300.
Carrier thermalization and zero-point bandgap renormalization in halide perovskites from the Urbach tails of the emission spectrum
Authors: Mukhuti Kingshuk , Mandal Arnab , Roy Basabendra , Bhattacharyya Sayan , Bansal Bhavtosh
Published: November 2022

We develop techniques to study the temperature dependent localization, thermalization, and the effects of phonon scattering on the excitons in halide perovskites from the analysis of the emission spectra. The excitonic Urbach edge, when inferred from the low energy tails of the temperature dependent luminescence spectra, is shown to be sensitive to the electron distribution and thermalization. A method to observe the Urbach focus is devised for halide perovskites where the temperature dependence of the excitonic gap is anomalous. The value of the zero-point bandgap renormalization is inferred to be about 33 meV. This small value of the bandgap renormalization rules out the formation of small polarons and points to weak electron–phonon coupling. The experiments are performed on the nanosheets of the archetypal halide perovskite, CsPbBr3.
500-period epitaxial Ge/Si0.18Ge0.82 multi-quantum wells on silicon
Authors: Assali S. , Koelling S. , Abboud Z. , Nicolas J. , Attiaoui A. , Moutanabbir O.
Published: November 2022

Ge/SiGe multi-quantum well heterostructures are highly sought-after for silicon-integrated optoelectronic devices operating in the broad range of the electromagnetic spectrum covering infrared to terahertz wavelengths. However, the epitaxial growth of these heterostructures at a thickness of a few micrometers has been a challenging task due to the lattice mismatch and its associated instabilities resulting from the formation of growth defects. To elucidate these limits, we outline herein a process for the strain-balanced growth on silicon of 11.1/21.5 nm Ge/Si0.18Ge0.82 superlattices (SLs) with a total thickness of 16 μm corresponding to 500 periods. Composition, thickness, and interface width are preserved across the entire SL heterostructure, which is an indication of limited Si–Ge intermixing. High crystallinity and low defect density are obtained in the Ge/Si0.18Ge0.82 layers; however, the dislocation pileup at the interface with the growth substrate induces micrometer-long cracks on the surface. This eventually leads to significant layer tilt in the strain-balanced SL and in the formation of millimeter-long, free-standing flakes. These results confirm the local uniformity of structural properties and highlight the critical importance of threading dislocations in shaping the wafer-level stability of thick multi-quantum well heterostructures required to implement effective silicon-compatible Ge/SiGe photonic devices.
Correlation between amplitude and phase photothermal signals based on Kramers–Kronig relations: Application to the investigation of interfacial thermal resistance in multilayers
Authors: Chirtoc M. , Horny N.
Published: November 2022

A general feature of frequency-domain photothermal (PT) experiments is that the signal phase follows the derivative of the log –log-amplitude. This is the consequence of the Kramers–Kronig (K–K) relations between real and imaginary parts of the thermal response of the system, represented by its thermal impedance. Simple expressions allow determining the phase from the amplitude, both theoretically and experimentally. They stem from the local Hilbert transform in differential form, instead of the traditional integral form which requires broadband information. These expressions are applied to the thermal impedance of a layered system. The measurements were performed in an earlier publication by photothermal radiometry (PTR) method to determine the interfacial thermal resistance between a 50 nm Ti layer and a steel or Si substrate. In this case, high frequency measurements are the most relevant, but they are also most prone to artifacts and background noise. It is concluded that the amplitude and phase results of Ti/steel samples are correctly linked to one another, but that the phase of Ti/Si samples violates the K–K relations at high frequency, probably due to a different signal generation mechanism than the PT one. The fact that PT phenomena are consistent with the K–K relations opens the possibility to check the self-consistency of the results obtained by PTR or by other related PT methods. It also reveals that the PT phase carries the same information as the signal amplitude, less a scaling factor that incorporates the thermal effusivity of a layer in the system.
Interfacial traps and band offset enabled charge separation facilitating current/capacitance hysteresis in dual-oxide layered structure
Authors: Lyu Cheng-Han , Chaurasiya Rajneesh , Lai Bo-Ru , Chen Kuan-Ting , Chen Jen-Sue
Published: November 2022

Gradual switching in the memristor or memcapacitor devices is the key parameter for the next generation of bio-inspired neuromorphic computing. Here, we have fabricated the WOx/ZrOx dual-oxide layered device, which shows the coexistence of gradual resistive and capacitive switching arisen from the current and capacitance hysteresis curves, respectively. The expansion of hysteresis loop can be modulated by altering the oxygen content in the oxide materials. Interestingly, the presence of negative differential resistance (NDR) is dependent on the voltage sweep direction and range of applied bias, which can be reasoned by the local electric field, charge trapping/detrapping, and conduction band offset at the dual-oxide interface. This study provides the concept of the coexistence of current and capacitance hysteresis along with NDR, and it is highly potential for memristor and memcapacitor circuits to explore neuromorphic computing.