bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural and Optical characterization of gamma irradiated PVA-PEG/Cr2O3nanocomposite films
Authors: Barakat Mai , Bahareth Radiyah , Mahrous Eman , Aldawood Saad , Nouh Samir
Published: March 2022

Polyvinyl alcohol-Polyethylene glycol/Chromium oxide nanocomposite (PVA-PEG/Cr2O3NCP) was synthesized by means of the thermolysis and casting procedures. The NCP films were irradiated with various X-ray dosages (15–130 kGy). The resultant outcome of the X-ray irradiation on the structural and optical characteristics of the NCP films were explored applying X-ray diffraction and UV spectroscopy. The optical band gap, refractive index, Urbach energy and optical dielectric parameters were characterized and interpreted based on the X-ray dosage. The optical bandgap dropped from 3.91 to 2.7 eV for a X-ray dosage of 130 kGy, accompanied with a rise in Urbach energy of the samples. We attribute this to the dominance of crosslinking. Additionally, the color differences between the pristine and the irradiated samples were characterized. The pristine NCP film was uncoloured. It exhibited noteworthy color changes during the X-ray irradiation, as the color intensity reached a value greater than 5. This is an acceptable match in commercial reproduction on printing presses.
An optimal ordering policy for a visitor-based purchasing system with stochastic delivery time and partial prepayment for profit maximization
Authors: Taleizadeh Ata Allah , Zarei Hamidreza , Sarker Bhaba R.
Published: March 2022

The classical inventory control policies assume that orders are paid for at the time of their receipts, but in practice, suppliers may require retailers to pay a fraction of the purchasing cost in advance, and sometimes allow them to pay this cost in several prepayments during a predetermined period. Planning inventory replenishments and prepayments become challenging when decisions must be made under uncertainty, especially when delivery time is stochastic, and shortages may occur. This paper develops an inventory control model in a purchasing system in which a visitor sells the product of a manufacturer, and a buyer receives call from the visitor to make an order and items arrives at stochastic time. Both partial prepayments and partial backordering are assumed in the model. The main aim of the paper is to determine the optimal level of inventory of the buyer such that his total profit is maximized. A mathematical model with a general probability distribution for lead time is developed and globally optimal solutions are derived for the model. The applicability of the model is discussed through two special cases for uniform and exponential probability distributions. The results are supportive of the proposed ideas and they reflect an efficient approach.
Preface
Authors: Martínez Francisco Javier , Miralles Buil Celia
Published: March 2022

This paper provides a quick overview of the theoretical outline, programme, organization, and participants of the 3rd QSN International Conference “Matters of Containment”. Originally intended as an in-person meeting to be held at premises of the University of Évora and the University of Lisbon, in Portugal, the conference finally took place online.
Non-radioactive but nuclear? Containment and circulation of wastes from the French nuclear tests in Polynesia
Authors: Meyer Teva
Published: March 2022

Beside Moruroa and Fangataufa, the two atolls where atomic bombs were detonated, the conduction of the French nuclear tests from 1966 to 1995 in Polynesia required the deployment of infrastructure throughout the whole archipelago. Their gradual decommissioning until the early 2010s produced massive volumes of wastes scattered through different islands. While being mainly non-radioactive but chemically polluted, the management and circulation of these materials, mainly consisting of gravels and soils, is currently stopped due to their perceived “nuclearity” (Hecht, 2012). Building on a case study developed in the atoll of Hao, which hosted the nuclear tests’ support base, this paper offers to document how these non-radioactive materials are defined as nuclear, thus confining their circulation. Results show that these wastes’ “nuclearity” results from their integration on multi-level conflicts.
Dilution or containment: controlling radioactive liquid effluents from the 1950s to the 1980s on Marcoule plant, France
Authors: Fagon Louis
Published: March 2022

Nuclear facilities constantly produce radioactive liquid effluents, as a part of their ordinary operation. However, controlling a circulating fluid is problematic. This paper focuses on Marcoule plant in Southern France, on the Rhône River, to document how radioactive effluent containment evolved from the 1950s to the early 1980s. The 1950s and 1960s were a time of experimentation: engineers intended to find a way to dilute radioactive wastes into the river, following a traditional conception inherited from the 19th century. However, due to multiple factors (scientific research and a better understanding of radiation effects, raising protests against nuclear wastes, first legislation on radioactive effluents), both guiding concepts and technical solutions evolved to a stricter containment and control of radioactive effluents.
Emigration and public health: the sanitary question in the control of Portuguese emigrants, 1890s-1950s
Authors: Santos Yvette
Published: March 2022

Human mobility represents a privileged field for analysing epidemic propagation, as well as identification and control practises at a world scale. Migrants are at the same time agents of disease dissemination and vulnerable persons highly exposed to epidemics in transit spaces such as city ports, ships, and settlement sites in the countries of origin. This paper aims to analyse how a country with a long and strong tradition in transatlantic and European migration, such as Portugal, incorporated concerns of Public Health in the policies and management of massive migration exits from the nineteenth century until the 1950s, particularly through the directives for the control and prevention of epidemics. In this way, we will analyse the intersection of two general state policies, epidemic control and migration surveillance.
Belastungsvorgaben nach distaler Femurfraktur - eine aktuelle Literaturübersicht
Authors: Braun Benedikt J. , Hofmann Kira , Rollmann Mika FR , Menger Maximilian M , Ahrend Marc-Daniel , Ihle Christoph , Histing Tina , Herath Steven C.
Published: March 2022

Die Inzidenz der distalen Femurfraktur steigt gerade auch bei geriatrischen Patienten deutlich an. Grundsätzliches Ziel der Behandlung dieser Verletzung ist eine frühzeitige Mobilisation
der Patienten zur Prävention immobilisationsassoziierter Begleiterkrankungen. Vor dem Hintergrund einer steigenden Anzahl an Therapieoptionen, wie der Doppelplattenosteosynthese,
Nagel-Platte-Kombinationen sowie dem distalen Femurersatz, gewinnen Überlegungen zur möglichen Belastung nach der Versorgung einen neuen Stellenwert. Ziel dieser Arbeit war es daher, die
bestehende Literatur der vergangenen 9 Jahre hinsichtlich Belastungsvorgaben und klinischer Ergebnisse der verschiedenen Therapieoptionen aufzuarbeiten und mit dem eigenen Vorgehen
abzugleichen.
Synthesis of (Z)-Cinnamate Esters by Nickel-Catalyzed Stereoinvertive Deoxygenation of trans-3-Arylglycidates
Authors: Akkarasamiyo Sunisa , Chitsomkhuan Saranya , Buakaew Supawadee , Samec Joseph S. M. , Chuawong Pitak , Kuntiyong Punlop
Published: March 2022

We report a stereoinvertive deoxygenation of trans-3-arylglycidates as an alternative route to access thermodynamically less stable (Z)-cinnamate esters by using nickel triflate and triphenylphosphine. Broad functional-group tolerance was observed, with trans-3-arylglycidates containing methyl, methoxy, halo, or nitro groups affording the corresponding (Z)-cinnamate esters in high yields and with moderate to high E/Z ratios.
Using quantum gravity to explore increasing entropy
Authors: Piccone Ashley
Published: March 2022

Extending Roger Penrose’s Weyl Curvature Hypothesis past classical gravity to the quantum regime
Attachment of a particle to a pendant drop: How large can we go?
Authors: Feng Yumeng , Zhao Weiwei , Duan Yangyu , Zhu Siqi , Zhang Xurui , Thoraval Marie-Jean
Published: March 2022

Small solid particles can be attached to an air–liquid interface due to the pulling of surface tension. We investigate experimentally under which conditions a spherical solid particle can be attached under a pendant drop, varying the density and diameter of the particle, as well as the size of the liquid drop. We demonstrate that depending on the drop size, the largest particle size that can be attached is limited by two different mechanisms, either falling from the nozzle together with the drop, or separating from the bottom of the liquid drop. Moreover, we show that for smaller volumes of the drop, a suction Laplace pressure can dramatically increase the maximum size of the particle that can be supported. Finally, we propose a theoretical model for each of these regimes to explain the maximum size of particle that can remain attached to a pendant drop.
Analytical study of two-layered mixed electro-osmotic and pressure-driven flow and heat transfer in a microchannel with hydrodynamic slippage and asymmetric wall heating
Authors: Banerjee Debanjan , Pati Sukumar , Biswas Pankaj
Published: March 2022

We investigate the fluid flow and heat transfer characteristics for a combined electro-osmotic and pressure-driven flow of two immiscible fluids through a straight planar microchannel considering the interfacial wall slip and slip-dependent zeta potential with asymmetric wall heating. Closed-form expressions are derived for the electrical potential distribution induced in the electrical double layer (EDL), velocity, temperature, and Nusselt number of both the layers after analytically solving the Poisson–Boltzmann equation, the mass, momentum, and energy conservation equations along with suitable boundary conditions for a steady incompressible hydrodynamically and thermally fully developed flow. The results for both the layers are presented for a broad range of parameters, such as dielectric constant ratio, pressure gradient, interfacial zeta potential difference, Debye–Hückel parameter, slip length, Joule heating parameter, Brinkman number, and heat flux ratio. The flow velocity is found to attain a higher value after considering the slip effect on zeta potential for all the parameters and for both fluids, and the enhancement in the velocity is more for thinner EDL. The heat transfer characteristics for the two layers are different, where the absolute value of the Nusselt number with the slip effect on zeta potential is always higher than that for the no-slip case for the bottom layer. Contrarily, the absolute value of the Nusselt number shows an opposite trend for the upper layer. Critical values of Brinkman numbers are obtained for the bottom layer beyond which the Nusselt number is higher for thicker EDL.
Observing wave–particle behavior of entangled atoms in cavity assisted delayed-choice experiment
Authors: Hamza Danish Ali , Abbas Tasawar , Asjad Muhammad , Imran Muhammad , Rameez-ul-Islam
Published: March 2022

A scheme is proposed to study the wave–particle duality of two entangled atoms in a cavity-QED framework. Two atoms may exhibit a mutating trend between particle and wave behaviors. This mutating behavior can be post-selected after the atomic states have been recorded on the state selective detectors. In the present proposal, second Hadamard transformation is always present, whereas the probabilities are the same as that in the case, where the state of the second Hadamard can be controlled by an ancilla. The whole scheme revolves around resonant, off-resonant, and Ramsey interactions of two level atoms with the field. To observe the desired behavior, cavity assisted atom-field multiple swappings are employed for tagging as well as for the better control and good fidelity.
Cavity quantum-electrodynamical time-dependent density functional theory within Gaussian atomic basis. II. Analytic energy gradient
Authors: Yang Junjie , Pei Zheng , Leon Erick Calderon , Wickizer Carly , Weng Binbin , Mao Yuezhi , Ou Qi , Shao Yihan
Published: March 2022

Following the formulation of cavity quantum-electrodynamical time-dependent density functional theory (cQED-TDDFT) models [Flick et al., ACS Photonics 6, 2757–2778 (2019) and Yang et al., J. Chem. Phys. 155, 064107 (2021)], here, we report the derivation and implementation of the analytic energy gradient for polaritonic states of a single photochrome within the cQED-TDDFT models. Such gradient evaluation is also applicable to a complex of explicitly specified photochromes or, with proper scaling, a set of parallel-oriented, identical-geometry, and non-interacting molecules in the microcavity.
Imaging sensor research for viscoelastic detection of composite resin
Authors: Xie ChengFeng , Xu XiaoJun , Xia NengHao , Liu YanSong , Zhao YouJiang , Shi Jiulin , Wang Mengyu , He XingDao
Published: March 2022

We present an imaging sensor used in the viscoelastic detection of composite resins. Composite resins are the mainstream materials in dental restorative procedures. After restoring the carious cavity, the module of the composite resin increases with the curing time of the light-curing unit. After a specific time, the composite resin is cured to the ideal state (not completely cured; this refers to the initial curing of the dental restorative material, after which it takes some time to cure completely). The sensor provides a new, fast, and non-contact optical method for module detection of composite resins. This study determined the time required to cure composite resins ideally by qualitative analysis of decorrelation time (τ) and quantitative module G*(w). The results showed that the composite resin cured ideally in the ninth second and exhibited a high linear correlation (r = 0.965, p = 0.007 81). The successful development of this sensor will help to avoid subjective judgment about the curing degree of composite resins and detect the curing process of composite resins.
Schottky diode characteristics on high-growth rate LPCVD
β
-Ga2O3 films on (010) and (001) Ga2O3 substrates
Authors: Saha Sudipto , Meng Lingyu , Feng Zixuan , Anhar Uddin Bhuiyan A. F. M. , Zhao Hongping , Singisetti Uttam
Published: March 2022

High crystalline quality thick β-Ga2O3 drift layers are essential for multi-kV vertical power devices. Low-pressure chemical vapor deposition (LPCVD) is suitable for achieving high growth rates. This paper presents a systematic study of the Schottky barrier diodes fabricated on four different Si-doped homoepitaxial β-Ga2O3 thin films grown on Sn-doped (010) and (001) β-Ga2O3 substrates by LPCVD with a fast growth rate varying from 13 to 21 μm/h. A higher temperature growth results in the highest reported growth rate to date. Room temperature current density–voltage data for different Schottky diodes are presented, and diode characteristics, such as ideality factor, barrier height, specific on-resistance, and breakdown voltage are studied. Temperature dependence (25–250 °C) of the ideality factor, barrier height, and specific on-resistance is also analyzed from the J–V–T characteristics of the fabricated Schottky diodes.
Radiation-induced defect accumulation and annealing in Si-implanted gallium oxide
Authors: Kjeldby S. B. , Azarov A. , Nguyen P. D. , Venkatachalapathy V. , Mikšová R. , Macková A. , Kuznetsov A. , Prytz Ø. , Vines L.
Published: March 2022

Defect accumulation and annealing phenomena in Si-implanted monoclinic gallium oxide (β-Ga2O3) wafers, having (2¯01), (010), and (001) orientations, were studied by Rutherford backscattering spectrometry in channeling mode (RBS/c), x-ray diffraction (XRD), and (scanning) transmission electron microscopy [(S)TEM]. Initially, the samples with different surface orientations were implanted with 300 keV 28Si+-ions, applying fluences in the range of 1 × 1014–2 × 1016 Si/cm2, unveiling interesting disorder accumulation kinetics. In particular, the RBS/c, XRD, and (S)TEM combined data suggested that the radiation disorder buildup in Si-implanted β-Ga2O3 is accompanied by significant strain accumulation, assisting crystalline-to-crystalline phase transitions instead of amorphization. Selected samples having (2¯01) orientation were subjected to isochronal (30 min) anneals in the range of 300–1300 °C in air. Systematic RBS/c and XRD characterization of these samples suggested complex structural transformations, which occurred as a function of the fluence and the temperature. Moreover, a detailed (S)TEM analysis of the sample implanted with 2 × 1016 Si/cm2 and annealed at 1100 °C was enhanced by applying dispersive x-ray and electron energy-loss spectroscopies. The analysis revealed silicon agglomerations in the form of silicon dioxide particles. Signal from silicon was also detected outside of the agglomerates, likely occurring as substitutional Si on Ga sites.
Thermo-capillarity in microfluidic binary systems via phase modulated sinusoidal thermal stimuli
Authors: Agrawal Shubham , Das Prashanta K , Dhar Purbarun
Published: March 2022

In this article, we have explored the theoretical aspects of thermo-capillarity driven hydrodynamics at the interface of an immiscible binary-fluid system within a microfluidic domain. The top and bottom walls of the microfluidic confinement are exposed to sinusoidal thermal stimuli with different mean values, wave numbers, and phase differences. We explore the influence of different governing parameters on the thermal and hydrodynamic transport due to interfacial thermo-capillarity and within the constituent fluids. To this end, we deduce the full solutions for the temperature field, hydrodynamics, and the interfacial deformation characteristics in an analytical framework, by appealing to the assumption of the creeping flow (vanishingly small Reynolds, Marangoni, and Capillary number regime) and nearly un-deformed interface. Complicated spatial distribution of the isotherms is generated across the fluids, leading to spatially varying thermal gradients across and along the interface. This leads to periodic circulation of the fluids within the microchannel due to the sinusoidal thermal stimulus. It is observed that the interfacial flow strength depends on the relative film thickness and the thermal conductivities of the two fluids. Vortex enveloping phenomenon is observed for lower values of film thickness ratio when the thermal conductivity of the lower fluid is higher relative to the upper fluid. The findings may hold significance for the design and development of thermal stimulus-controlled spatial mixing and solute transport mechanisms in reactive micro- and nano-fluidic devices.
Measurement of the Hugoniot and shock-induced phase transition stress in wrought 17-4 PH H1025 stainless steel
Authors: Specht Paul E. , Reinhart William , Scott Alexander C.
Published: March 2022

Uniaxial strain, reverse-ballistic impact experiments were performed on wrought 17-4 PH H1025 stainless steel, and the resulting Hugoniot was determined to a peak stress of 25 GPa through impedance matching to known standard materials. The measured Hugoniot showed evidence of a solid–solid phase transition, consistent with other martensitic Fe-alloys. The phase transition stress in the wrought 17-4 PH H1025 stainless steel was measured in a uniaxial strain, forward-ballistic impact experiment to be 11.4 GPa. Linear fits to the Hugoniot for both the low and high pressure phase are presented with corresponding uncertainty. The low pressure martensitic phase exhibits a shock velocity that is weakly dependent on the particle velocity, consistent with other martensitic Fe-alloys.
Simultaneous resolution of photon numbers and positions with series-connected superconducting nanowires
Authors: He Guanglong , Li Haochen , Yin Rui , Zhang Labao , Dong Daxing , Lv Jiayu , Fei Yue , Wang Xiaohan , Chen Qi , Li Feiyan , Li Hui , Wang Hao , Tu Xuecou , Zhao Qingyuan , Jia Xiaoqing , Chen Jian , Kang Lin , Wu Peiheng
Published: March 2022

In this Letter, we report on a device with which to resolve photon numbers and positions simultaneously, using single-channel readout from superconducting nanowire single-photon detectors (SNSPDs). The nanowires in the SNSPDs are connected in series with parallel resistors for producing response pulses with different amplitudes, whose values obey a distribution of 1:2:4:,..,2n-1. In single-photon detection, a saturated counting rate is obtained at a low dark count rate (<10 cps). Furthermore, we observed 16 output modes corresponding one-to-one with 16 states (15 photon responses + 1 state without photons) in multiphoton mode. This structure not only inherits the advantages of high quantum efficiency and low dark count rate of traditional SNSPD, but also realizes the resolution of photon position and number simultaneously without complicated optical system. Thus, this proposal offers a promising platform for realizing scalable and practical quantum information chips.
Giant widening of interface magnetic layer in almost compensated iron garnet
Authors: Kudasov Yu. B. , Logunov M. V. , Kozabaranov R. V. , Makarov I. V. , Platonov V. V. , Surdin O. M. , Maslov D. A. , Korshunov A. S. , Strelkov I. S. , Stognij A. I. , Selemir V. D. , Nikitov S. A.
Published: March 2022

A two-sublattice ferrimagnet undergoes a transition from a collinear to the canted magnetic phase at magnetic field oriented along an easy magnetization direction. In this work, we study the transition by means of the magneto-optical Faraday effect in a thin film of compensated iron garnet (Lu3−xBix)(Fe5−y−zGayAlz)O12 grown on the Gd3Ga5O12 substrate. In the immediate vicinity of the compensation temperature, a precursor of the transition with a complex shape was observed. Using a special sample with variable thickness, we demonstrate an interfacial origin of the precursor. Diffusion of gadolinium from the substrate into the film forms a thin intermixed layer with enhanced magnetization. It induces an extended inhomogeneous magnetic structure in the film. A two-step shape of the precursor appears due to an easy-plane anisotropy of the intermixed magnetic layer. We emphasize that an effective width of the inhomogeneous magnetization distribution in the film grows enormously while approaching the compensation temperature.
Experimental study of gas breakdown and electron emission in nanoscale gaps at atmospheric pressure
Authors: Wang Haoxuan , Brayfield Russell S. , Loveless Amanda M. , Darr Adam M. , Garner Allen L.
Published: March 2022

While experiment, simulation, and theory all show that the gas breakdown voltage decreases linearly with gap distance for microscale gaps at atmospheric pressure due to the contribution of field emitted electrons, the continuing reduction in device size motivates a more fundamental understanding of gas breakdown scaling for nanoscale gaps. In this study, we measure current–voltage curves for electrodes with different emitter widths for 20–800 nm gaps at atmospheric pressure to measure breakdown voltage and assess electron emission behavior. The breakdown voltage Vb depends more strongly on effective gap distance deff than the ratio of the emitter width to the gap distance. For 20 and 800 nm gaps, we measure Vb≈5 V and Vb≈275 V. Independent of emitter width, Vb decreases linearly with decreasing deff for deff≳200 nm; for deff<200 nm, Vb decreases less rapidly with decreasing deff, which may correspond to a change in the field enhancement factor for smaller gaps. While gas breakdown usually proceeds directly from field emission, as for microscale gaps, some cases exhibit space-charge contribution prior to the transition to breakdown, as demonstrated by orthodoxy tests. Applying nexus theory, we determine that the range of deff studied is close to the transitions between field emission and space-charge-limited current in vacuum and with collisions, necessitating a coupled theoretical solution to more precisely model the electron emission behavior. Implications on device design and an overall assessment of the dependence of emission and breakdown on gap distance are also discussed.
Tunable work function of molybdenum oxynitride for electron-selective contact in crystalline silicon solar cells
Authors: Gu Zeyu , Li Le , Du Guanlin , Lin Yinyue , Lu Linfeng , Chen Jia , Du Zheren , Liu Ronglin , Cheng Quan , Gao Kun , Yang Xinbo , Li Dongdong
Published: March 2022

Dopant-free carrier-selective contacts based on metal compounds have attracted considerable attention for high-efficiency crystalline silicon solar cells. In this work, the feasibility of using molybdenum oxynitride (MoOxNy) as an electron-selective contact layer in n-type crystalline silicon (n-Si) solar cells has been demonstrated. With the increase in the N2:Ar ratio during the sputtering process, the work function of a MoOxNy film decreases from 4.57 to 4.26 eV, which is advantageous for the MoOxNy film to be an electron transport layer. An efficiency of 18.0% has been achieved in n-Si based solar cells using a full-area MoOxNy contact for electron extraction, featuring a high fill factor of 84.6%.
Electronic structure and open-orbit Fermi surface topology in isostructural semimetals NbAs2 and W2As3 with extremely large magnetoresistance
Authors: Lou Rui , Wang Yiyan , Zhao Lingxiao , Xu Chenchao , Li Man , Chen Xiaoyang , Zhang Anmin , Huang Yaobo , Cao Chao , Chen Genfu , Xia Tianlong , Zhang Qingming , Ding Hong , Wang Shancai
Published: March 2022

In transition-metal dipnictides TmPn2 (Tm = Ta and Nb; Pn = P, As, and Sb), the origin of extremely large magnetoresistance (XMR) is yet to be studied by the direct visualization of the experimental band structures. Here, using angle-resolved photoemission spectroscopy, we map out the three-dimensional electronic structure of NbAs2. The open-orbit topology contributes to a non-negligible part of the Fermi surfaces (FSs), like that of the isostructural compound MoAs2, where the open FS is proposed to likely explain the origin of XMR. We further demonstrate the observation of open characters in the overall FSs of W2As3, which is also a XMR semimetal with the same space group of C12/m1 as the TmPn2 family and MoAs2. Our results suggest that the open-orbit FS topology may be a shared feature between XMR materials with the space group of C12/m1 and, thus, could possibly play a role in determining the corresponding XMR effect together with the electron–hole compensation.
Growth-dependent structural ordering and stability in β-tungsten films for spintronic applications
Authors: Chattaraj Ananya , Asirvatham Joshua , Das Gangadhar , Manna Gouranga , Saha Pinku , Kumar Vijay , Kanjilal Aloke
Published: March 2022

The β phase of tungsten has attracted great interest for spintronic applications due to its higher spin Hall angle compared to other elemental solids and large spin–orbit torque, but the stability of this phase is yet to be well understood as many different results are there in the literature mainly based on the film thickness, temperature, and overall growth conditions. The growth of films by sputter deposition has emerged as a promising technique to achieve β-W owing to its compatibility with current spintronic technology. We demonstrate here the efficient ability of dc magnetron sputtering to grow stable β-W films up to a thickness of ∼180 nm at room temperature by varying a set of deposition parameters like pressure, power, and deposition time and discuss the various underlying mechanisms. From these results, the optimized set of deposition parameters for growing β-W films is given. A clear understanding of the influence of oxygen in the atomic structure of β-W is obtained by varying the thickness of the films. This is confirmed from the ab initio molecular dynamics (MD) simulations, where the atomic structure is influenced by the oxygen doping concentration. A stable polycrystalline β phase can be achieved by controlled doping of oxygen. Additionally, a phase transformation from α to β with the doping of oxygen is also evident by MD simulations.
An underwater planar lens for broadband acoustic concentrator
Authors: Ma Fuyin , Zhang Hao , Du Pengyu , Wang Chang , Wu Jiu Hui
Published: March 2022

In this Letter, a single-cavity underwater acoustic metasurface unit with sub-wavelength thickness was designed for simultaneously realizing the high refractive index in the water environment. By arraying several metasurface units with a gradient index distribution in the radial direction, a gradient-index three-dimensional planar underwater acoustic lens was constructed. Moreover, a lens with fewer units was designed to reduce the radial size by nearly a half to the original one while maintaining the excellent broadband focusing capability unchanged. In addition, by adding a back cavity on the focusing side of the lens, a lens-based acoustic concentrator was proposed which could greatly enhance the sound energy gain in a wide frequency range. Finally, samples of the underwater acoustic planar lens and concentrator were fabricated and measured in an anechoic tank, which verified that the designed underwater acoustic concentrator has excellent broadband sound energy enhancement performance. The underwater acoustic planar lens and concentrator proposed in this work have potential application values including but not limited to underwater target detection and acoustic energy harvesting.
Production of thick Gd freestanding films for energy conversion applications
Authors: Ba Doan Nguyen , Becerra Loic , Marangolo Massimiliano , Almanza Morgan , LoBue Martino
Published: March 2022

The use of magnetocaloric material in microelectromechanical energy conversion devices requires freestanding films with smooth surfaces to allow fast and efficient heat transfer. We present and discuss a mechanical method to produce freestanding thick Gadolinium films showing excellent magnetic properties, and high-quality surfaces on both sides. Polycrystalline Gd films have been prepared by sputtering on a silicon substrate with a thermally oxidized layer with different thicknesses. Films have been grown at 543 K. Tantalum and Tungsten have been used as buffer layers because of their corrosion resistance and of their thermal conductivity. The magnetic and surface properties of the freestanding films are presented, with special focus on the role of using different capping layers. Full characterizations of the three freestanding Gd films, including AFM measured surface roughness, XRD patterns, Curie temperature, thermo-magnetic curves, and maximum entropy change, are presented and discussed.
Anomalous magnetic properties of GdCrTiO5 nanoparticles
Authors: Bharati B. , Mohanty P. , Sheppard C. J. , Prinsloo A. R. E.
Published: March 2022

In this report, the structural and magnetic properties of GdCrTiO5 nanoparticles were explored, which were synthesized through the sol-gel technique and subsequently calcined (at 800 °C). X-ray diffraction (XRD) studies revealed the orthorhombic crystal structure of synthesized GdCrTiO5 nanoparticles with space group Pbam. The transmission electron microscopy (TEM) images, with selected area electron diffraction (SAED) pattern, showed the particle size as 38.0 ± 0.4 nm and single crystalline nature of the sample. The temperature dependence of dc magnetization, M(T), was measured for GdCrTiO5 nanoparticles, and different magnetic transitions were confirmed, including the spin reorientation (TSR), Néel temperature (TN) and compensation temperatures (Tcomp1 and Tcomp2) in the material. Irreversibility appeared in field-cool-cooling (FCC), and field-cool-warming (FCW) curves at low temperatures, indicating a ferromagnetic-antiferromagnetic (FM-AFM) transition. Earlier, this FM-AFM transition and TSR, Tcomp was not observed in bulk GdCrTiO5. Both the FM nature and exchange bias (EB) effect are further established from the field-dependent magnetization measurements. Furthermore, a change in isothermal magnetic entropy (−ΔSm) of 22 ± 3 J.kg-1.K-1 is found below 10 K, for a 7 T difference in the field. The obtained magnetic properties in this report are discussed in terms of exchange frustration originating from the competing interactions of the magnetic sublattices of the Cr3+ and Gd3+ in the GdCrTiO5 nanoparticles.
Infrared laser annealing of nanocomposite Nd–Fe–B/Mo/FeCo multilayered magnet films
Authors: Koike Kunihiro , Uchida Tokunosuke , Sakurai Keiho , Inaba Nobuyuki , Kato Hiroaki , Itakura Masaru , Hara Shigeo , Saito Yu , Okubo Susumu , Ohta Hitoshi
Published: March 2022

The formation of nanocomposite Nd-Fe-B/Mo/FeCo multilayered magnet films using the infrared laser annealing technique. The perpendicular magnetic anisotropy of the film with Mo interlayer was larger than that of the film without Mo interlayer before annealing. Magnetic properties of both films were drasticly changed from soft magnetism to hard magnetism with in-plane magnetic anisotropy after the infrared laser annealing process at 760°C. Coercivity of in-plane annealed film with Mo interlayer was about 10 kOe which was double that of the film without Mo interlayer. In second quadrant, squareness of demagnetization curve of infrared laser annealing processed film with Mo interlayer was better than that of film without Mo interlayer. The infrared laser annealing process crystallizes the amorphous phase of the Nd-Fe-B layer as well as the multi-step annealing, even though the infrared laser annealing process time is only 1/100 of the process time of the multi-step annealing using halogen lamps reported previously.
Magnetocaloric effect in melt-spun rare earth intermetallic compound ErAl2
Authors: Prusty Mitali Madhusmita , Chelvane J. Arout , Morozkin A. V. , Gururaj Karanam , Pradeep K. G. , Paulose P. L. , Nirmala R.
Published: March 2022

Laves phase rare earth intermetallic compound ErAl2 (Cubic, MgCu2-type) has been prepared by melt-spinning process. Analysis of powder X-ray diffraction data of melt-spun ErAl2 yields crystallite size of about 54 nm. Transmission electron microscopy image reveals particles of size ∼70 nm. The melt-spun ErAl2 orders ferromagnetically ∼10 K (TC) whereas the ferromagnetic ordering temperature is ∼14 K for the arc-melted ErAl2 compound. From the magnetization vs field data, isothermal magnetic entropy change (ΔSm) has been computed as a function of temperature near TC. The maximum ΔSm value in the melt-spun ErAl2 is ∼ −34 Jkg−1K−1 at 14 K for 70 kOe field change whereas the corresponding value in the arc-melted sample is ∼ −42 Jkg−1K−1 at 16 K. Thus, rapid solidification results in crystalline, coarse grained ErAl2 with submicron sized particles leading to only minor changes in the magnetic and magnetocaloric properties.
Sensitivity of rift tectonics to global variability in the efficiency of river erosion
Authors: Olive Jean-Arthur , Malatesta Luca C. , Behn Mark D. , Buck W. Roger
Published: March 2022

Significance

The efficiency of erosion in leveling relief mainly depends on climate and strength of exposed rocks. However, whether erosion is sufficiently efficient to influence the architecture of a tectonic plate boundary remains a topic of debate. Here, we analyze continental rift landscapes reworked by river incision to assess a globally representative range of fluvial erosion efficiency. We then simulate crustal extension exposed to surface processes acting within this documented range. We find that more efficient erosion favors the growth of half-grabens over horsts, which can explain contrasting tectonic styles across the Basin and Range province and the East African Rift. This suggests that variability in Earth’s geological structures partly reflects variability in hydrological conditions and associated surface processes.
Structure and mechanism for iterative amide
N
-methylation in the biosynthesis of channel-forming peptide cytotoxins
Authors: Cogan Dillon P. , Bhushan Agneya , Reyes Reyvin , Zhu Lingyang , Piel Jörn , Nair Satish K.
Published: March 2022

Significance

The channel-forming proteusins are bacterial helical peptides that allow permeation of positively charged ions to influence membrane potential and cellular physiology. We biochemically characterize the effect of two critical posttranslational modifications on the secondary structure of the peptide substrate. We determine how a methyl group can be added to the side chains of D-Asn residues in a peptide substrate and show how flanking residues influence selectivity. These studies should foster the development of small-molecule peptide ion channels as therapeutics.
Adjustable object floating states based on three-segment three-phase contact line evolution
Authors: Li An , Li Huizeng , Zhao Zhipeng , Xue Luanluan , Li Zheng , Li Kaixuan , Li Mingzhu , Song Yanlin
Published: March 2022

Significance

Adjusting the floating states when objects float on water shows great potential for assembly, mineral flotation, nanostructured construction, and floating robot design, but the real-time regulation of floating states is challenging. Inspired by the different floating states of a falling fruit, we propose a facile strategy to transform the object between different floating states based on a three-segment three-phase contact line evolution. In addition, the potential of floating state transformation in solar-powered water evaporation, interface catalysis, and drug delivery is demonstrated. These findings provide insights into floating regulation and show great potential for floating-related applications.
Collocations as a Language Resource
Authors: Poulsen Sonja
Published: March 2022

Are collocations problems or solutions to problems? If you take the perspective of the foreign learner, as in traditional phraseology, they are certainly challenging, and they have therefore been categorized as arbitrary, or even defective, deviations from an assumed norm of full compositionality. This is a paradox because their ubiquity in language and their importance for language proficiency are undisputed. The book provides a critical review of the traditional phraseological approach to collocations with its classical categories and its roots in structural and generative linguistics as well as traditional Russian phraseology. Instead, it proposes a theory of collocations as an independent functional domain, no longer characterized as “odd comings-together of words” that are neither fully compositional nor fully idiomatic. It fills a research gap and should appeal to phraseologists and cognitive linguists as well as psycholinguists, neurolinguists, corpus linguists, PhD-students and other advanced students of linguistics who are interested in exploring collocations as a language resource and may be interested in contributing to it.
Breaking the mold
Authors: Barkley Katharina , Okamoto Emi
Published: March 2022

This study investigated the potential effects of CEO gender and ethnicity on crisis communication efforts in Japan. Literature on how Japanese perceive male/female and Japanese/non-Japanese leaders was examined, followed by a discussion of three major mechanisms through which gender and ethnicity can influence audience perceptions: (1) ingroup bias, (2) role congruity considerations, and (3) shifting standards and expectations. A 2 (crisis response) × 2 (CEO gender) × 2 (CEO ethnicity) between-subjects experimental design was employed to assess the impact of CEO gender and ethnicity on audience perceptions of the CEO and the organization in crisis. Results showed no negative effects of deviating from the stereotypical image of a male Japanese CEO. Rather, both being female and non-Japanese positively influenced perceptions of the CEO. However, only the effect of CEO ethnicity was reflected in judgements of organizational reputation.
Pitfalls of production data analysis for investigating L2 cognitive mechanism
Authors: Fukuta Junya , Nishimura Yoshito , Tamura Yu
Published: March 2022

This article addresses the pitfalls of performance analysis in investigating cognitive processing during second
language (L2) learning. The problems that we discuss in this paper are twofold: (1) Assuming psychological variables to be
ontological entities without meeting the criteria for ontological reality and (2) Inappropriateness of assessing abilities based
on learner’s speaking or writing performance to investigate cognitive processes. By addressing these problems, we argue that some
latent variables postulated by observing L2 performance do not exist in reality and emphasize the difficulty of interpreting
cognitive mechanisms through performance analysis. We also enumerate some problems that arise from the epistemological
perspectives of previous research practice (e.g., the bifurcation of contradictory hypotheses and their indeterminacy). Finally,
two alternative approaches treating L2 performance are proposed. The implications of this line of discussion for future research
are also discussed.
How to Teach an Additional Language
Authors: Van den Branden Kris
Published: March 2022

This book provides a comprehensive, research-based account of how people learn a second/foreign language and shows how classroom practice can be organised around research-based principles. In the first part, the book provides up-to-date insights into the cognitive, motivational, and emotional dimensions of learning an additional language. In the second part, ten principles of high-quality additional language teaching are introduced and illustrated by a wealth of authentic, classroom-based examples. The book also explores implications for curriculum design and the assessment of additional language competences. A separate chapter is devoted to the ways in which innovation in language education can be fostered. Throughout the book, the question is addressed whether additional language teaching should primarily focus on meaningful tasks, form-based practice, or the integration of both. This book is a must-read for all those who are interested in improving the quality of second and foreign language education.
Lymph node fibroblastic reticular cells regulate differentiation and function of CD4 T cells via CD25
Authors: Kim Dongeon , Kim Mingyo , Kim Tae Woo , Choe Yong-ho , Noh Hae Sook , Jeon Hyun Min , Kim HyunSeok , Lee Youngeun , Hur Gayeong , Lee Kyung-Mi , Shin Kihyuk , Lee Sang-il , Lee Seung-Hyo
Published: March 2022

Lymph node fibroblastic reticular cells (LN-FRCs) provide functional structure to LNs and play important roles in interactions between T cells and antigen-presenting cells. However, the direct impact of LN-FRCs on naive CD4+ T cell differentiation has not been explored. Here, we show that T cell zone FRCs of LNs (LN-TRCs) express CD25, the α chain of the IL-2 receptor heterotrimer. Moreover, LN-TRCs trans-present IL-2 to naive CD4+ T cells through CD25, thereby facilitating early IL-2–mediated signaling. CD25-deficient LN-TRCs exhibit attenuated STAT5 phosphorylation in naive CD4+ T cells during T cell differentiation, promoting T helper 17 (Th17) cell differentiation and Th17 response-related gene expression. In experimental autoimmune disease models, disease severity was elevated in mice lacking CD25 in LN-TRCs. Therefore, our results suggest that CD25 expression on LN-TRCs regulates CD4+ T cell differentiation by modulating early IL-2 signaling of neighboring, naive CD4+ T cells, influencing the overall properties of immune responses.
Interface effects on heat dynamics in embedded metal nanoparticles during swift heavy ion irradiation
Authors: Jantunen Ville , Leino Aleksi , Veske Mihkel , Kyritsakis Andreas , Vázquez Muiños Henrique , Nordlund Kai , Djurabekova Flyura
Published: March 2022

Swift heavy ion (SHI)-induced shape modification of metal nanoparticles (NPs) embedded in an insulating matrix has been reported in many experimental studies. The shaping process was studied theoretically by modeling transport of the heat generated by electron excitations during a SHI impact on the embedded NP. These models have assumed that the interface between the matrix and the metal does not alter the heat flow. However, the difference between the Fermi level of the metal and the bottom of the conduction band in the insulator may result in a significant energy barrier that obstructs the free flow of the heat carried by energetic electrons. Moreover, the interface may enhance electron-lattice scattering and resist lattice heat conduction. In this work, we use the finite-element method to solve partial differential equations for heat conduction through the interface between the metal NP and the insulating matrix including interface effects. Based on an exemplary case of a gold NP embedded in a silica matrix, we study how the processes at the interface may alter the heat transport through it. We observe that obstruction at the interface impacts mainly the timescale and efficiency of material melting. Each of the studied effects changes the size and shape of the NP regions, where the temperature rises above the melting point. Understanding the role of the interface on heat dynamics during SHI impacts can improve estimations of the maximal size of embedded NPs that are still susceptible to shape modification by energetic ions. The accuracy of model predictions can be crucial for the development of nanoscale optoelectronic applications.
Device physics of homojunction perovskite solar cells: a design omitting all the charge transport layers with efficiency exceeding 26.3%
Authors: Da Yun , Xie Meiqiu
Published: March 2022

Perovskite solar cells (PSCs) omitting all the charge transport layers with p–n homojunction structure are considered a promising alternative for commercialization owing to their low fabrication cost and simplified structure. Deep understanding of the device physics of these all-free p–n homojunction structured PSCs is of paramount importance. Here, a thorough investigation of all-free perovskite–perovskite p–n homojunction structured PSCs is performed by using a photoelectrical coupling model. Four different configurations including a standard n–i–p cell, electron transport layer-free cell, hole transport layer-free cell, and all-free cell are compared to identify the limiting performance factors, and the results indicate that no extra built-in electric field in the perovskite layer and severe surface recombination occurring at the perovskite interface are the two main factors limiting the power conversion efficiency (PCE) of all-free p–n homojunction structured PSCs. Based on doping engineering, a highly efficient all-free p–n homojunction structure is designed, which consists of an asymmetric p–n junction with both a front surface field layer and a back surface field layer. The effects of optical loss, thickness of the emitter, doping concentration for both the emitter and base, and diffusion length on the performance of p–n homojunction structured PSCs are optimized. After optimization, the PCE of the all-free p–n homojunction structured PSCs reaches 26.33%, which is slightly higher than that of a standard n–i–p heterojunction cell (26.22%). This work demonstrates that all-free p–n homojunction structured PSCs are a promising alternative to standard n–i–p heterojunction structured PSCs for realizing high efficiency, which may pave the way toward commercialization of PSCs in the future.