bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Extracorporeal Circuit Prime Volume Reduction on Whole Blood Sequestration During Acute Normovolemic Hemodilution for Adult Cardiac Surgery Patients
Authors: Loubser Paul G. , Morell Rose I. , Loubser Ileana A.
Published: August 2023

Acute normovolemic hemodilution (ANH) is a blood-conservation method in which whole blood (WBANH) is sequestered into blood collection bags before the commencement of surgery. However, for cardiac surgery, extracorporeal circuit (ECC) priming techniques limit the amount of blood that may collected prior to the actual initiation of cardiopulmonary bypass (CPB). In this study, computational modeling was used to examine the effect of reducing extracorporeal “pump” prime volume (PPV) on WBANH prior to the CPB. Increments of estimated blood volume (EBV), precardiopulmonary bypass hemoglobin concentration [HbPre-CPB], and PPV volume were manipulated to assess effects on predicted hemoglobin concentration during cardiopulmonary bypass [HbCPB]. Similarly, increments of EBV and preanesthetic hemoglobin concentration [HbPre-Anes] were manipulated to examine the change in WBANH volume. The impact of PPV reduction on the minimum acceptable precardiopulmonary bypass hemoglobin concentration [HbPre-CPB-MA] was then measured by computing PPV, EBV, and the minimum acceptable cardiopulmonary bypass hemoglobin [HbCPB-MA]. Finally, by manipulating EBV and target hemoglobin concentration [HbTarget], the change in [HbPre-CPB] produced by PPV reduction was used to quantify the effect on WBANH volume. The net increase in the [HbCPB] produced by PPV reduction is inversely proportional to EBV. Higher [HbPre-Anes] or lower [HbTarget] facilitates sequestration of larger WBANH volume. Although PPV and [HbPre-CPB-MA] bear a direct relationship, as EBV decreases, proportionally greater increases in [HbPre-CPB-MA] occur. The impact of PPV reduction on precardiopulmonary bypass hemoglobin concentration [HbPre-CPB] is reflected by the “excess hemoglobin” over the minimum hemoglobin threshold (designated as 7 g/dL in this study). For each 100-mL decrement in PPV, “excess hemoglobin” increases from 1% (EBV = 8000 mL) to 2% (EBV = 4000 mL). In turn, increases in “excess hemoglobin” are associated with expansion of WBANH volume. In conclusion, sequential PPV reduction from 2000 mL increases the volume of WBANH that potentially may be sequestered prior to initiation of CPB. Therefore, the combination of PPV reduction with ANH may represent a useful blood conservation approach in adult patients undergoing cardiac surgery with CPB.
Resuscitation of Fat Embolism Syndrome With Extracorporeal Membrane Oxygenation
Authors: Webb David P. , McKamie Wes A. , Pietsch John B.
Published: August 2023

Embolization of marrow fat appears to be an inevitable consequence of long bone fractures. Pulmonary fat embolism (FE) with cardiovascular collapse is associated with a high mortality rate because of acute right ventricular failure and hypoxia. Immediate and appropriate resuscitation is required to prevent sudden death. Although extracorporeal membrane oxygenation (ECMO) has been used for a multitude of applications involving respiratory and circulatory collapse, its full potential as a standard conventional therapy has yet to be exploited. Herein, we describe the successful use of veno-venous (V-V) ECMO in a trauma patient who initially presented with fractures of the right ulna and femur. After surgery, the patient rapidly decompensated despite massive ventilatory support and was placed on ECMO. ECMO support lasted approximately 120 hours followed by an uneventful recovery and discharge 10 days later.
Myocardial Reperfusion Injury: Etiology, Mechanisms, and Therapies
Authors: Hoffman John W. , Gilbert Timothy B. , Poston Robert S. , Silldorff Erik P.
Published: August 2023

Reperfusion of ischemic myocardium is required for tissue survival; however, reperfusion elicits pathologic consequences. Myocardial reperfusion injury is a multifarious process that is mediated in part by oxygen free radicals, neutrophil–endothelium interactions, apoptosis, and intracellular calcium overload. The oxygen paradox describes the contradictory need to delivery oxygen to ischemic tissue and the resultant reduction of oxygen to form free radicals that are involved in macromolecule oxidation, membrane disfunction, apoptosis, and damaged calcium sequestering ability, which results in hypercontracture. These cell-damaging crises are amplified by the excessive activation of neutrophils, which promote the formation of proinflammatory mediators, oxygen radicals, and the reduction of endothelial nitric oxide formation, leading to increased neutrophil–endothelium interactions and capillary occlusion. Neutrophil action is twofold, however, because it is required for necrotic debris removal after severe ischemia. The oxygen radicals produced by neutrophils, endothelium, and myocytes may also play a role in activating the apoptotic cascade. Although the role of apoptosis in reperfusion injury is controversial, apoptotic cells are found in infarcted tissue. One of the key mediators may be increased inner mitochondrial membrane permeability, resulting in reduced ATP formation, release of cytochrome c, and caspase activation, which is key to promotion of apoptosis. Increased mitochondrial membrane permeability occurs during exposure to supraphysiological calcium concentrations. This occurs because of compensatory Na+/Ca2+ exchange to remove the excess intracellular sodium resulting from decreased Na+/K+ pumping during ischemia and increased Na+/H+ exchange following reperfusion. Supraphysiological calcium elicits hypercontracture and cellular damage. The various therapies being developed to diminish myocardial reperfusion injury involve inhibition of the processes described above as well as others. Although single therapies have shown some promise, the complexity of the response to reperfusion has made dramatic improvement elusive. Effective treatment will most likely require multifaceted antagonism of the numerous pathological cascades initiated by reperfusion.
Malmquist index evaluation of countries: 2000–2019
Authors: Farnoudkia Hajar
Published: August 2023

One of the sophisticated mathematical techniques for evaluating the relative efficiency of decision-making units (DMUs) in a multi-inputs-output setting is data envelopment analysis. A non-parametric productivity index called the Malmquist index (MI) tracks changes in a DMU’s overall factor output over time. This study seeks to present a broad overview of the changes in the MI for nearly all of the world’s nations over 19 years beginning in 3061. This research evaluates a time series data set made up of 16 economic indexes. Each nation’s MI, which compares 2000 and 2019, shows how each nation has changed over that period. One of the most important purposes of this study comparing the countries by their MI is that it allows for a fair comparison of productivity across different time periods and regions. It also provides insights into the sources of productivity growth, such as changes in technology or improvements in efficiency. As a result, the countries can allocate resources more wisely and develop more effective investment plans by understanding the elements that lead to productivity increase. By implementing some statistical techniques, nations are further divided into four categories based on their MI. Furthermore, a yearly distribution of the MI has been included to illustrate its trends between the years 2000 to 2019. Finally, the changing flow for some countries of each category is shown in three-year tracks.
Optimal cooperation modes and information strategies under asymmetric sustainable investment efficiency
Authors: Zhou Jianheng , Shen Yiting , Li Hong , Chen Xingli
Published: August 2023

Currently, sustainability is of widespread concern among consumers and branders, compelling an increasing number of suppliers to invest in sustainable practices. This paper establishes a supply chain model comprising a supplier with private investment efficiency and a brander. By employing signaling and reverse selection theories, the equilibrium strategies of the supplier and the brander are explored. Additionally, the impact of investment efficiency and the probability of H-type on the brander’s information strategy and optimal cooperation mode are analyzed. Our analyses reveal that concealing private information may not be beneficial to the supplier under the quotation mode. Moreover, when the probability of H-type is low, the supplier prefers to signal its exact type to the brander. Under the bidding mode, the brander may benefit more from not obtaining the exact supplier type. When the efficiency difference is higher and the probability of H-type is smaller, the brander indicates a preference for the quotation mode and is more willing to await a signal from the supplier. Furthermore, different information structures yield different optimal cooperation modes for the brander.
Umgang mit erhöhten Ferkelverlusten nach Auftreten von
exsudativer Epidermitis – ein Fallbericht
Authors: Brimmers Lutz , Buch Juhle , Harlizius Jürgen , Kuczka Annette , Kleinmans Michael , Ladinig Andrea , Kreutzmann Heinrich
Published: August 2023

Exsudative Epidermitis (EE) – meist, aber nicht ausschließlich
ausgelöst durch Staphylococcus (St.) hyicus – ist ein
verbreitetes Problem auf Ferkelerzeugerbetrieben. So auch in einem westdeutschen
eigenremontierenden Betrieb mit 350 produktiven Sauen. Beginnend mit
schwärzlich-schuppigen Hautläsionen bei einzelnen Saug- und
Aufzuchtferkeln sowie Jung- und Altsauen, bestand bereits in der
nächsten Absetzgruppe bei etwa 50% der Ferkel die klinische
Verdachtsdiagnose der EE. Die Mortalitätsrate im Aufzuchtstall stieg bei
betroffenen Ferkelgruppen auf 10%. Sowohl die (histo)pathologische
Untersuchung als auch der wiederholte Nachweis von St. hyicus aus
Hauttupfern sowie Tupfern aus anderen Organen bestätigten die klinische
Verdachtsdiagnose. Neben St. hyicus konnte aus einzelnen Hauttupfern
zudem St. chromogenes isoliert werden. In der weiterführenden
Charakterisierung der St. hyicus-Stämme wurden ExhA und SHETA als
beteiligte Toxine identifiziert, und die Isolate zeigten unter anderem
Resistenzen gegen Penicilline und Aminopenicilline. Kurzfristig verbesserte eine
bestandsweise antibiotische Therapie mit einem Trimethoprim-Sulfadiazin-haltigen
Präparat in Kombination mit der individuellen Behandlung einzelner Tiere
und dem Waschen mit einer jodhaltigen Lösung die klinische Symptomatik.
Zur dauerhaften Reduktion des Einsatzes antibiotischer Mittel wurde sich
für die Herstellung eines bestandsspezifischen Impfstoffs mit den
isolierten St. hyicus- und St. chromogenes-Stämmen
entschieden, welcher als Mutterschutzvakzine an die Sauen appliziert wurde.
Zusätzlich wurde die externe und interne Biosicherheit anhand eines
objektiven Fragebogens (Bio-check.UGentTM) evaluiert und angepasst.
Die Kombination der Maßnahmen führte zu einer langfristigen
Besserung des klinischen Geschehens. Das erneute Auftreten leichter
Hautläsionen bei einzelnen Ferkeln konnte mit der Anpassung des
bestandsspezifischen Impfstoffes durch neu gewonnene St. hyicus-Isolate
zielführend in den Griff bekommen werden. Der Fallbericht verdeutlicht,
wie mit der Kombination aus kontinuierlichem Monitoring, Einzeltier- und
Gruppentherapie, Evaluierung der Biosicherheit und dem Einsatz einer
angemessenen Immunprophylaxe selbst hartnäckige Fälle der EE auf
ein Minimum reduziert werden können.
Neonatal Onset Distal Renal Tubular Acidosis: Description of Two Novel Variants on the ATP6V0A4 Gene and Review of the Literature on Associated Extrarenal Manifestations
Authors: Antoniadi Marita , Lambrou Dimitra , Mylona Fani , Florentin Lina , Bili Chrysanthi , Stefanidis Constantinos J. , Kostaridou Stavroula
Published: August 2023

Distal renal tubular acidosis (dRTA) is an extremely rare disease that affects the distal tubule's ability to excrete proton cations, acidify urine, and maintain the acid–base balance. The clinical presentation of dRTA typically includes normal anion gap metabolic acidosis with decreased serum bicarbonate levels, hypokalemia, hypercalcemia, nephrocalcinosis, and alkaline urine. Hereditary causes of dRTA include pathogenic variants in ATP6V1B1, ATP6V0A4, SLC4A1, FOXI1, and WDR72 genes, which encode different transmembrane proteins on the apical surface of type A intercalated cells in the distal tubule. Variants in these genes lead to various defects in the function of the encoded proteins and can also account for extrarenal manifestations of dRTA due to the expression of these proteins in other organs, such as the stria vascularis of the inner ear. However, the literature on extrarenal manifestations, associated renal complications of hereditary dRTA, and appropriate investigations, and follow-up for patients with dRTA is scarce. In this article, we present a challenging case of neonatal-onset dRTA and contribute two novel variants of the ATP6V0A4 gene and a novel phenotype associated with a pathogenic variant on ATP6V0A4 to the scientific community. We also review the existing literature on hereditary causes of dRTA, with emphasis on associated renal and extrarenal complications.
Craniosynostosis
Authors: Jackson I. T. , Dubin B. , Chandra Ramesh , Chabra D. K. , Singh Arun Kumar , Kumar Pramod
Published: August 2023

A 4 year old female child with Graniosynostosis (Grouzon's syndrome) was operated upon on 10.3.87, during the Ist National Workshop on Plastic Surgery at the King George's Medical College, Lucknow, in collaboration with the department of Neuro Surgery. The details of planning, management and the result of treatment in her is being presented.
Raidal Forearm Island Flap in the Management of Severe Adduction Contracture of Thumb
Authors: Kalra G. S. , Bhatnagar S. K. , Chandra R. , Pandey S. D.
Published: August 2023

The use of radial forearm flap as a distally based island flap for severe adduction contracture of thumb is being presented. The advantages and vascular basis of this flap has been discussed.
Tissiers's 0-14 Flefts
Authors: Bhattacharya S. , Bhatnagar S. K. , Pradhan K. L. , Singh A. K. , Chandra R.
Published: August 2023

Clefts on 0-14 axis of Tessier have two distinctly different presentations. With a hypoplastic presentation there is an involvement of the forebrain and as ‘face foretells the brain’ a severe hypoteloric appearance is always associated with severe brain damage and poor life expectancy. With hypertelorism however the spectrum of presentation may extend from the less severe hypertelorism alone to the most severe form of median cleft lip and palate, bifid nose and cranium bifidum accultum which are amenable to corrective craniofacial surgery.
Characteristics of the pressure profile in the accelerator on the RF negative ion source at ASIPP
Authors: Wu Mingshan , Xu Luxiang , Zhou Yanbo , Liang Lizhen , Zheng Yelong
Published: August 2023

Neutral beam injection (NBI) systems based on negative hydrogen ion sources—rather than the positive ion sources that have typically been used to date—will be used in the future magnetically confined nuclear fusion experiments to heat the plasma. The collisions between the fast negative ions and neutral background gas result in a significant number of high-energy positive ions being produced in the acceleration area, and for the high-power long-pulse operation of NBI systems, this acceleration of positive ions back to the ion source creates heat load and material sputtering on the source backplate. This difficulty cannot be ignored, with the neutral gas density in the acceleration region having a significant impact on the flux density of the backstreaming positive ions. In the work reported here, the pressure gradient in the acceleration region was estimated using an ionization gauge and a straightforward 1D computation, and it was found that once gas traveled through the acceleration region, the pressure dropped by nearly one order of magnitude, with the largest pressure drop occurring at the plasma grid. The computation also revealed that the pressure drop in the grid gaps was substantially smaller than that in the grid apertures.
Spectral localization for semimetals and Callias operators
Authors: Schulz-Baldes Hermann , Stoiber Tom
Published: August 2023

A semiclassical argument is used to show that the low-lying spectrum of a self-adjoint operator, the so-called spectral localizer, determines the number of Dirac or Weyl points of an ideal semimetal. Apart from the ion-mobility spectrometer localization procedure, an explicit computation for the local toy models given by a Dirac or Weyl point is the key element of proof. The argument has numerous similarities to Witten’s reasoning leading to the strong Morse inequalities. The same techniques allow to prove a spectral localization for Callias operators associated with potentials with isolated gap-closing points.
3D printing technique and its application in the fabrication of THz fibers and waveguides
Authors: Xu Guofu , Skorobogatiy Maksim
Published: August 2023

3D printing, also known as additive manufacturing technique, has recently found applications in various engineering fields due to its ability to produce freeform 3D structures beyond the ability of traditional subtractive manufacturing methods. In this respect, the field of THz photonics is no exception. The adoption of 3D printing technique resulted in a revolution in THz optics and device manufacturing and will continue advancing this field for years to come. In this Perspective paper, we consider, in particular, the fabrication of guided optics devices for the THz operation range using additive manufacturing. We first introduce the technical characteristics of various 3D printing techniques as well as the advantages, disadvantages, and main performance parameters. Then, various 3D printed THz waveguides and fibers and functional devices, such as metalized/metallic/dielectric rectangular waveguides, photonic crystal waveguides, hollow-core anti-resonant/Bragg waveguides, hybrid metal/dielectric waveguides, plasmonic waveguide, porous fibers, magic tee, and serpentine waveguide traveling-wave circuits, are discussed. We also highlight practical applications of 3D printed waveguides/fibers in manipulating THz waves, especially in the fields of sensing and communication, including the analyte thickness and refractive index sensors, subwavelength/suspended core fiber communication links, dispersion compensators, and add-drop multiplexers. Finally, the prospects of 3D printing techniques in the THz field are summarized.
Hysteresis-free high mobility graphene encapsulated in tungsten disulfide
Authors: Soundarapandian Karuppasamy Pandian , De Fazio Domenico , Bernal-Texca Francisco , Hoffmann Rebecca , Ceccanti Matteo , De Bonis Sergio L. , Tongay Sefaattin , Koppens Frank H. L.
Published: August 2023

High mobility is a crucial requirement for a large variety of electronic device applications. The state of the art for high-quality graphene devices is based on heterostructures made with graphene encapsulated in >40 nm-thick flakes of hexagonal boron nitride (hBN). Unfortunately, scaling up multilayer hBN while precisely controlling the number of layers remains an outstanding challenge, resulting in a rough material unable to enhance the mobility of graphene. This leads to the pursuit of alternative, scalable materials, which can be used as substrates and encapsulants for graphene. Tungsten disulfide (WS2) is a transition metal dichalcogenide, which was grown in large (∼mm-size) multi-layers by chemical vapor deposition. However, the resistance vs gate voltage characteristics when gating graphene through WS2 exhibit largely hysteretic shifts of the charge neutrality point on the order of Δn∼ 3 × 1011 cm−2, hindering the use of WS2 as a reliable encapsulant. The hysteresis originates due to the charge traps from sulfur vacancies present in WS2. In this work, we report the use of WS2 as a substrate and overcome the hysteresis issues by chemically treating WS2 with a super-acid, which passivates these vacancies and strips the surface from contaminants. The hysteresis is significantly reduced by about two orders of magnitude, down to values as low as Δn∼ 2 × 109 cm−2, while the room-temperature mobility of WS2-encapsulated graphene is as high as ∼62 × 103 cm2 V−1 s−1 at a carrier density of n ∼ 1 ×1012 cm−2. Our results promote WS2 as a valid alternative to hBN as an encapsulant for high-performance graphene devices.
Excitons dynamic modulation by tailoring size of high-entropy Mo0.64W0.36S2 alloy
Authors: Kang Jianlong , Wang Yiduo , Zhou Li , Al-Hartomy Omar A. , Wageh S. , Wang Yingwei , Zhang Han , Xiao Si , He Jun
Published: August 2023

Two-dimensional transition metal disulfides with tailored optical response are vital to demonstrate versatile optoelectronic devices and nanophotonic elements. In this work, using transient absorption spectroscopy in conjunction with density functional theory calculations, we demonstrate ultrafast excitons absorption modulation via tailoring the size of a transition-metal dichalcogenide alloy Mo0.64W0.36S2 nanosheet. As the size of the nanosheet increases from 9 ± 5 to 190 ± 121 nm, peak positions of the A and B excitons vary from 666 to 675 nm and 626 to 638 nm, respectively. Furthermore, the decay lifetimes of A excitons slow down from 1.16 to 1.84 ps when the size changes from 9 ± 5 to 190 ± 121 nm. It is shown that the exciton diffusion and decay properties can be modulated by the components and structure modulation, which is beneficial for the optimal design and optimization of optoelectronic devices.
Shock-induced transformation of nitinol shape memory alloy: Effect of stress state on transformation
Authors: Ning Jialong , Ding Jow-Lian
Published: August 2023

Due to its numerous practical applications and intriguing phase transformation behavior, shape memory alloys (SMAs) have garnered significant research and development interests. In the past, most studies on the mechanical behavior of SMAs have been conducted under uniaxial stress loadings. Limited research on SMAs under shock loading has not provided conclusive results regarding their transformation behavior and transformation stress under such loading. Additionally, there is a lack of comprehensive understanding regarding the effects of different stress states on transformation behavior. The main objectives of this study are to address these issues. To achieve these objectives, a series of shock wave experiments were designed and conducted. Additionally, quasi-static and dynamic uniaxial stress experiments were carried out to establish a baseline for comparison. The results revealed that the transformation stress under dynamic uniaxial strain shock loading was approximately 1.92 GPa in contrast to 0.5 GPa (quasi-static) to 0.8 GPa (dynamic) observed in uniaxial stress loading. The transformation behavior exhibited noticeable rate sensitivity for both types of loading. There appeared to be a critical strain rate above which the austenite phase was driven to a metastable state. This estimated critical axial strain rate along the loading direction was approximately 2 × 103/s–4 × 103/s for uniaxial stress loading and approximately 2 × 106/s for uniaxial strain loading. The apparent high transformation stress for uniaxial strain loading can likely be attributed to a combination of high-pressure confinement and high strain rate. However, determining their relative contributions remains an open issue.
Effects of wake interaction on energy extraction performance of tandem semi-active flapping foils
Authors: Zhao Fuwang , Wang Zhaokun , Qadri M. Nafees Mumtaz , Khan Omer , Munir Adnan , Shahzad Aamer , Tang Hui
Published: August 2023

A numerical investigation was carried out to analyze the interactions between semi-active tandem flapping foils at various tandem distances with a chord-based Reynolds number of 1100. Results indicate that with a tandem distance of less than 1.5 chord lengths and released in-phase, both foils exhibited terminal periodic motions with a nonzero mean stagger distance. In contrast, under the other conditions, the two foils ended up with periodic flapping motions without stagger. Due to the high-pressure region near the leading edge of the aft foil, the heaving motion of the fore foil resulted in lower energy extraction performance than that of single foil, when the tandem distance was less than 5 chord lengths. However, as the tandem distance increased, the fore foil acted like a single foil. The aft foil demonstrated significant fluctuations in performance parameters when subjected to the wake of the fore foil. The favorable interaction between the wake and aft foil resulted in lower power consumption for pitching and enabled the aft foil to extract an additional 15.2% power compared to a single foil. Conversely, during the unfavorable wake–foil interaction, the pitching motion of the aft foil consumed more energy than energy extraction from the heaving motion, leading to net energy consumption. The initial inter-foil pitching phase difference also significantly influenced the performance of the aft foil. Two models, the global phase and the wake phase model, affect these tandem configurations, both proving effective in capturing these effects with the wake phase model displaying notable efficacy.
From ultra-fast growth to avalanche growth in devitrifying glasses
Authors: Yanagishima Taiki , Russo John , Dullens Roel P. A. , Tanaka Hajime
Published: August 2023

During devitrification, pre-existing crystallites grow by adding particles to their surface via a process that is either thermally activated (diffusive mode) or happens without kinetic barriers (fast crystal growth mode). It is yet unclear what factors determine the crystal growth mode and how to predict it. With simulations of repulsive hard-sphere-like (Weeks–Chandler–Andersen) glasses, we show for the first time that the same system at the same volume fraction and temperature can devitrify via both modes depending on the preparation protocol of the glass. We prepare two types of glass: conventional glass (CG) via fast quenching and uniform glass (UG) via density homogenization. First, we bring either glass into contact with a crystal (X) and find the inherent structure (CGX/UGX). During energy minimization, the crystal front grows deep into the CG interface, while the growth is minimal for UG. When thermal noise is added, this behavior is reflected in different crystallization dynamics. CGX exhibits a density drop at the crystal growth front, which correlates with enhanced dynamics at the interface and a fast growth mode. This mechanism may explain the faster crystal growth observed below the glass transition experimentally. In contrast, UGX grows via intermittent avalanche-like dynamics localized at the interface, a combination of localized mechanical defects and the exceptional mechanical stability imposed by the UG glass phase.
Formation of 2D GaXY (X = S, Se; Y = F, Cl, Br, I) with enhanced piezoelectricity via decomposition of Ga-monochalcogenide by halogenation
Authors: Guo Rui , Zhao Rui , Ge Yanfeng , Liu Yong , Wan Wenhui
Published: August 2023

Motivated by the excellent electronic and optoelectronic properties of two-dimensional (2D) Ga-monochalcogenides, we systematically investigated the effect of halogenation on physical properties of monolayer GaX (X = S, Se) by the first-principles calculations. Crystal lattices of GaX were decomposed with the halogen atom being absorbed on top of the Ga atom. Unexpectedly, a series of monolayer GaXY (X = S, Se; Y = F, Cl, Br, I) was formed. Except for GaXF, other monolayer GaXY has good structural stability at room temperature. With the broken mirror symmetry, monolayer GaXY has superior flexibility, a direct bandgap in the range of 0.78–4.43 eV, the intrinsic vertical polarization, and larger in-plane as well as out-of-plane piezoelectric coefficients than Ga-monochalcogenides. Moreover, by comparing the structural stability and side-dependent electronic band alignment, we concluded that monolayer GaXY (X = S, Se; Y = Cl, Br) is suitable for photocatalytic water-splitting applications.
Structural relaxation of water during rapid cooling from ambient temperatures
Authors: Kringle Loni , Kay Bruce D. , Kimmel Greg A.
Published: August 2023

Experiments investigating the properties of deeply supercooled liquid water are needed to develop a comprehensive understanding of water’s anomalous properties. One approach involves transiently heating nanoscale water films into the supercooled region for several nanoseconds at a time and then interrogating the water films after they have quenched to cryogenic temperatures. To relate the results obtained with this approach to other experiments and simulations on supercooled water, it is important to understand how closely the quenched structure tracks the (metastable) equilibrium structure of water as a function of the transient heating temperature. A key step involves quantifying the extent to which water that is transiently heated to ambient temperatures [hyperquenched water (HQW)] subsequently relaxes toward the structure of low-density amorphous (LDA) ice as it cools. We analyzed the infrared reflection–absorption spectra of LDA, HQW, and crystalline ice films to determine their complex indices of refraction. With this information, we estimate that HQW retains ∼50%–60% of a structural motif characteristic of water at high temperatures with the balance comprised of a low-temperature motif. This result, along with results from x-ray diffraction experiments on water and amorphous ices, allows one to quantify the fraction of the high-temperature motif at approximately zero pressure as a function of temperature from 150 to 350 K.
Temperature dependence of incommensurate modulation in Ca0.28Ba0.72Nb2O6
Authors: Beanland R. , Harrison L. , Khan S. , Brown T. , Roncal-Herrero T. , Peirson H. , Brown A. P. , Milne S. J.
Published: August 2023

We present an electron microscopy and diffraction study of a CaxBa1−xNb2O6 ceramic with x=0.28 (CBN28), a ferroelectric material with a partially filled tetragonal tungsten-bronze structure. The microstructure has strong similarities to that of SrxBa1−xNb2O6, with an average orthorhombic symmetry and an intimate intermixture of merohedral twin variants at a length scale of tens of nanometers. Superstructure spots in diffraction patterns are displaced by a one-dimensional incommensurate modulation, characterized by a propagation vector δδ0. Heating experiments show that δ is strongly coupled to ferroelectric polarization, decreasing as 180° ferroelectric domains become more finely spaced and needle-like as the Curie temperature TC is approached during heating and increasing once more above TC. No change in symmetry is observed at TC, consistent with a transition from ferroelectric to antiferroelectric (or ferrielectric) relaxor properties. The superstructure spots and incommensurate modulation disappear ∼250°C above TC, consistent with polar regions in the material becoming fully transient.
Droplet actuation by coupling corona discharge and contact electrification: Domino coalescence and uphill braking
Authors: Tian Ye , Wang Hong , Tian Yuchen , Zhu Xun , Chen Rong , Ding Yudong , Liao Qiang
Published: August 2023

Directed transport and control of droplets is essential for many modern technologies. Here, we propose an active control mode that combines corona discharge and contact electrification to efficiently drive the droplet or droplet group in a directed manner. In particular, we also implement a continuous coalescence of droplets, similar to dominoes. Moreover, due to the high adhesion effect caused by contact electrification, the droplet can stick on a slope without sliding down, even when the corona discharge is turned off. Interestingly, it can easily slide down when a conductor is nearby. Therefore, a droplet climbing, braking, and downhill system can be realized, and the gravitational potential energy stored by the droplet can be effectively regulated by the applied voltage. This work opens the possibility of droplet manipulation in modern applications such as miniaturized energy storage, biochemical medicine, and self-cleaning.
Large magneto-thermal-switching ratio in superconducting Pb wires
Authors: Yoshida M. , Arima H. , Yamashita A. , Uchida K. , Mizuguchi Y.
Published: August 2023

Thermal switching by magnetic fields is one of the important functionalities in thermal management technologies. In low-temperature devices, superconducting states can be used as a magneto-thermal-switching (MTS) component because carrier thermal conductivity (κ) is strongly suppressed in superconducting states. Recently, we demonstrated that the MTS ratio (MTSR) of pure Nb reached 650% at a temperature (T) of 2.5 K under a magnetic field (H) of 4.0 kOe [Yoshida et al., Appl. Phys. Express 16, 033002 (2023)]. In this study, to enrich knowledge on MTS of superconductors, the MTSRs of pure Pb wires with 5 N and 3 N purities were investigated by measuring the temperature or magnetic-field dependences of κ. For 5N-Pb, a large MTSR exceeding 1000% was observed below 3.6 K under H > 600 Oe. Although higher MTSRs were expected at lower temperatures under H > 600 Oe, the obtained data under those conditions were accompanied by large errors due to magnetic-field-induced huge κ at low temperatures. In contrast, the κ for 3N-Pb was observed to be clearly lower than that for 5N-Pb. Although the magnetic-field-induced change in κ was small, the MTSR at T = 2.5 K was 300%. These results suggest that Pb is a promising material for low-temperature magneto-thermal switching because of wide-range κ tunable by magnetic field and purity.
Flexural gravity wave interaction with an articulated heterogeneous plate within the paradigm of blocking dynamics
Authors: Negi P. , Kar P. , Sahoo T. , Meylan M. H.
Published: August 2023

Surface gravity waves interact with the flexural waves to generate the flexural gravity waves whose characteristics are triggered for higher values of lateral compressive stress to generate multiple propagating wave modes. This investigation examines the scattering of obliquely incident flexural gravity waves due to articulation in two semi-infinite heterogeneous floating elastic plates in finite water depth within a blocking dynamics regime. The dispersion curve demonstrates the existence of three propagating wave modes within the blocking limits. The canonical eigenfunction expansion method used for a single propagating mode is generalized to account for multiple propagating wave modes within the limits of blocking periods. The energy relation is established using the conservation of wave energy flux and Snell's law of refraction, which depends upon the angles and amplitude of the scattered waves along with the wave energy transfer rates. The amplitude of scattering coefficients (energy transfer rate) goes beyond the unit, where the corresponding energy transfer rate (scattering coefficients) diminishes for specific wave periods. Subsequently, complete wave reflection occurs for oblique waves beyond a critical angle of incidence for a fixed period and prior to a critical angle of incidence at a higher angle of incidence. Removable discontinuities occur at the blocking and saddle points, while a jump discontinuity appears due to a change in the incident wave mode in the scattering coefficients. Surface plots reveal the irregular pattern of plate deflection for the period within the blocking limits. Linear time-dependent plate displacement is simulated in two and three dimensions.
Hypervelocity imperfect gas nozzle design with shared wave-elimination contour
Authors: Zhang Bo , Yi Shihe , Zhao Yuxin , Yang Rui , He Lin , Lu Xiaoge
Published: August 2023

A hypervelocity imperfect gas nozzle with a shared wave-elimination contour is designed by the residual correction method, allowing the test Mach number to be varied by changing the throat contours. Owing to imperfect gas effects, the nozzle designed by the classical method of characteristics with boundary layer correction does not produce a uniform flow field, resulting in significant deviation from the target Mach number. In this work, the computational fluid dynamics solver is used as an independent module without being coupled to the optimization code, reducing the design complexity. Designers can choose the appropriate solver according to the specified physical characteristics to consider imperfect gas effects. The Mach 15 hypervelocity nozzle designed by the residual correction method better eliminates the Mach waves and achieves a much higher flow uniformity than the nozzle designed by the classical method. On this basis, the dependence domain of the shared wave-elimination contour and the influence domain of the transonic solution are solved by the method of characteristics, and a replaceable throat contour is rigorously designed from aerodynamics theory. Quantitative evaluations show that the nozzles with a shared wave-elimination contour have the same level of flow uniformity, achieving high flow quality at Mach 13–15. The evaluation results validate the design's feasibility, supporting the future construction of hypervelocity tunnels.
SWIR anti-reflective nanostructures on nonlinear crystals by direct UV femtosecond laser printing
Authors: Syubaev Sergey , Modin Evgeny , Gurbatov Stanislav , Cherepakhin Artem , Dostovalov Alexandr , Tarasova Aleksandra , Krinitsin Pavel , Yelisseyev Alexander , Isaenko Ludmila , Kuchmizhak Aleksandr
Published: August 2023

Nonlinear infrared (IR) crystals for radiation conversion are of paramount importance for realization of advanced laser spectrometers for medical diagnostics, environmental monitoring, and advanced sensing. However, performance of such crystals suffers from substantial surface reflectivity coming from rather high (over 2.5) refractive index of the key nonlinear materials used. Here, based on the example of promising BaGa4Se7 nonlinear crystal, we attested direct surface patterning with ultraviolet (257 nm) femtosecond laser pulses used to engrave anti-reflective microstructures (ARMs) directly on both output sides of the crystal. Imprinted surface nanotrenches arranged into a fish-net morphology with a periodicity down to 500 nm was found to increase transmittance of the crystals from 65% to 84% within a practically relevant shortwave IR spectral range. Formation of the ARMs with an optimized geometry is expected to weakly reduce the laser damage threshold of a pristine crystal material as it was also evidenced from supporting full-wave simulations and tests.
Growth rate of CO2 and CH4 hydrates by means of molecular dynamics simulations
Authors: Blazquez S. , M. Conde M. , Vega C. , Sanz E.
Published: August 2023

CO2 and CH4 hydrates are of great importance both from an energetic and from an environmental point of view. It is therefore highly relevant to quantify and understand the rate with which they grow. We use molecular dynamics simulations to shed light on the growth rate of these hydrates. We put the solid hydrate phase in contact with a guest aqueous solution in equilibrium with the pure guest phase and study the growth of both hydrates at 400 bars with temperature. We compare our results with previous calculations of the ice growth rate. We find a growth rate maximum as a function of the supercooling in all cases. The incorporation of guest molecules into the solid structure strongly decelerates hydrate growth. Consistently, ice grows faster than either hydrate and the CO2 hydrate grows faster than the CH4 one because of the higher solubility of CO2. We also quantify the molecular motion required to build the solids under study and find that the distance traveled by liquid molecules exceeds by orders of magnitude that advanced by any solid. Less molecular motion is needed in order for ice to grow as compared to the hydrates. Moreover, when temperature increases, more motion is needed for solid growth. Finally, we find a good agreement between our growth rate calculations and experiments of hydrate growth along the guest–solution interface. However, more work is needed to reconcile experiments of hydrate growth toward the solution among each other and with simulations.
Tension-induced magnetic Barkhausen noise morphology transition caused by pre-introduced strain
Authors: Wang Zhijun , Shi Pengpeng , Chen Hong-en , Liang Tianshou , Deng Ke , Chen Zhenmao
Published: August 2023

Magnetic Barkhausen noise (MBN) technology is widely used to reveal the microscopic mechanism of magnetomechanical phenomena, but the morphological transition induced by tension has not yet been confirmed by experimental measurements. Here, we report a novel effect on the morphology transition of MBN signals due to tensile stress with pre-introduced strain. We present a power-law relation between the critical stress for the morphology transition and the degree of pre-introduced strain, highlighting the strong correlation between plastic deformation and MBN response. Through comprehensive microscopic simulations, we reveal that dislocations localized in regions with distinct densities trigger different MBN avalanches, thereby leading to a bimodal morphology of the MBN signal. Upon reloading, an effective field introduced by stress promotes the realignment of the magnetic domains, thereby resulting in the formation of a unimodal morphology of the MBN signal. Our unprecedented findings provide valuable insights into the correlation between deformation and MBN signal response, thereby opening a new avenue for designing and optimizing ferromagnetic materials with tailored magnetic behavior.
Linear magnetic susceptibility of anisotropic superconductors of cuboidal shape
Authors: Prozorov Ruslan
Published: August 2023

A simplified model of anisotropic magnetic susceptibility in the Meissner–London vortex-free state of cuboidal superconducting samples is presented. Using this model, precision measurements of the magnetic response in three perpendicular directions of a magnetic field with respect to primary crystal axes can be used to extract the components of the London penetration depth, thus enabling the evaluation of the general superfluid density tensor, which is needed in the analysis of the superconducting gap structure.
A collaborative primary health care model for children and young people in rural Australia: explorations of cross-sectoral leader action
Authors: Randall Sue , White Danielle , Dennis Sarah
Published: August 2023

Background Cross-sectoral collaborations are considered necessary to address detrimental health, social, educational and economic outcomes that impact marginalised and disadvantaged populations. There is a strong relationship between the health of children and their educational attainment; good health promotes positive learning. This paper reports cross-sectoral executive and senior management level systems changes required to enable the design of a collaborative primary healthcare service model for children and young people in rural Australia. Methods A descriptive qualitative design was used. Data were collected from executive and senior managers from three organisations (Education, Health and a University Department of Rural Health [n = 6]) through individual semi-structured interviews. Data were analysed using an inductive, thematic approach. The study draws on Lewin’s Model of Change. Results Three overarching themes were generated from the data: an embedded challenge and experimental solutions; building a shared language and understanding; and the role of relationships and trust. Despite the unique geographical and social context of the study area, strategies emerged from the data on how a solution to an embedded challenge, through design of a primary healthcare model, was established and how the strategies described could be transferred and scaled to other rural and remote communities. Conclusion Contextual differences make each rural and remote area unique. In this study, strategies that are described in the managing change literature were evident. The authors conclude that drawing on strong management of change principles could mean that a service model designed for one remote community might be transferrable to other communities.
Sex-linked gene traffic underlies the acquisition of sexually dimorphic UV color vision in
Heliconius
butterflies
Authors: Chakraborty Mahul , Lara Angelica Guadalupe , Dang Andrew , McCulloch Kyle J. , Rainbow Dylan , Carter David , Ngo Luna Thanh , Solares Edwin , Said Iskander , Corbett-Detig Russell B. , Gilbert Lawrence E. , Emerson J. J. , Briscoe Adriana D.
Published: August 2023

The acquisition of novel sexually dimorphic traits poses an evolutionary puzzle: How do new traits arise and become sex-limited? Recently acquired color vision, sexually dimorphic in animals like primates and butterflies, presents a compelling model for understanding how traits become sex-biased. For example, some
Heliconius
butterflies uniquely possess UV (ultraviolet) color vision, which correlates with the expression of two differentially tuned UV-sensitive rhodopsins, UVRh1 and UVRh2. To discover how such traits become sexually dimorphic, we studied
Heliconius charithonia
, which exhibits female-specific UVRh1 expression. We demonstrate that females, but not males, discriminate different UV wavelengths. Through whole-genome shotgun sequencing and assembly of the
H. charithonia
genome, we discovered that
UVRh1
is present on the W chromosome, making it obligately female-specific. By knocking out
UVRh1
, we show that UVRh1 protein expression is absent in mutant female eye tissue, as in wild-type male eyes. A PCR survey of
UVRh1
sex-linkage across the genus shows that species with female-specific UVRh1 expression lack
UVRh1
gDNA in males. Thus, acquisition of sex linkage is sufficient to achieve female-specific expression of
UVRh1
, though this does not preclude other mechanisms, like
cis
-regulatory evolution from also contributing. Moreover, both this event, and mutations leading to differential UV opsin sensitivity, occurred early in the history of
Heliconius
. These results suggest a path for acquiring sexual dimorphism distinct from existing mechanistic models. We propose a model where gene traffic to heterosomes (the W or the Y) genetically partitions a trait by sex before a phenotype shifts (spectral tuning of UV sensitivity).
Optical properties of methyl-substituted germanane monolayer in the presence of the external magnetic field, strain and spin–orbit coupling
Authors: Abdi Mona , Astinchap Bandar
Published: August 2023

In this research, we use the tight-binding model, which includes spin–orbit coupling and an external magnetic field, to describe the optical properties of the methyl-substituted germanane (GeCH3) monolayer. We have applied the Kubo formula, linear response theory, and Green’s function approach to calculate the optical absorption coefficient of the GeCH3 monolayer. Here, the effects of an external magnetic field, strain, spin–orbit coupling, temperature, and electron/hole doping on the frequency dependence behavior of the optical conductivity have been investigated in detail. Our numerical results show that with increasing the external magnetic field, strain, and electron doping, the weight of the Drude increases. The optical absorption peak decreases and shifts to higher frequencies by applying an external magnetic field, strain, and electron doping. Controlling the optical and electronic properties of GeCH3 is leading to use this structure it in the electronic and optoelectronic industries.