bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of oscillating plates at the visco-inertial regime for bio-inspired pumping and mixing applications
Authors: Semati A. , Amani E. , Saffaraval F. , Saffar-Avval M.
Published: October 2020

In this numerical study, flow driven by oscillating plates in a channel is investigated at the intermediate Reynolds regime by means of the arbitrary Lagrangian–Eulerian method. The effects of temporal asymmetry, Reynolds number, channel height, phase differences between adjacent plates, and orientation angle on pumping performance, which are unclear under temporally asymmetric linear plate kinematics, are studied. By examining efficiency measures, new insight is gained from energy, mixing, and combined flowrate/energy standpoints. Furthermore, the mixing performance of oscillating plates, which is to a large extent unknown at the visco-inertial regime, is scrutinized. By studying a finite number of plates, end effects that are not apparent in the more common studies on infinite plate/cilia arrays are accounted for. For a single plate, results show an almost threefold increase in the average flow rate between Reynolds numbers of 5 and 40 but a fall thereafter caused by the restriction of the flow by a region of circulation. The average flow rate and energy conversion efficiency increase by 20% when the orientation angle is increased from −4° to 12°, and a point of maximum flow generation is found at a plate length to channel height ratio of 0.7. For an array of five plates, a phase difference of 90° between adjacent plates (antiplectic metachronal wave) generates the largest flow, while a phase difference of 270° (symplectic metachronal wave) brings about the best mixing efficacy. This suggests that the optimal phase difference depends on the intended use of the device.
On non-Newtonian effects in fluidic shock-absorbers
Authors: Goldstein L. , Ilssar D. , Gat A. D.
Published: October 2020

Shock-absorbers often involve throttling of viscous fluids through small orifices. This gives rise to high rates-of-strain and non-Newtonian behavior even in fluids which are commonly assumed Newtonian, which affects impact mitigation properties. We here derive an asymptotic approximation describing the dynamics of fluidic shock-absorbers while focusing on weak Carreau type non-Newtonian effects and annular geometries. We validate our model by numerical computations and experiments with a medium-sized shock-absorber used to mitigate the impact caused by a free-falling weight. We then leverage the theoretical model to calculate the shock-absorber's optimal geometry and present experimental results of the fabricated optimal configuration, showing good agreement with the theory and nearly optimal impact mitigation properties.
Effect of trailing-edge bevel on the aeroacoustics of a flat-plate
Authors: Celik A. , Bowen J. Luke , Azarpeyvand M.
Published: October 2020

An experimental study was conducted to investigate the effect of the bevel angle on the radiated noise and the associated flow-field over the trailing-edge. The bevel angle of the trailing-edge was adjusted over a broad range of angles to demonstrate the aeroacoustic properties of the attached and separated boundary layers. The far-field noise results obtained from the beamforming array were assessed in conjunction with the associated flow-field. Far-field measurement results show an increased level of radiated noise for a range of bevel angles where the flow remains attached compared to the baseline flat-plate case without a bevel angle. Near-field measurements are presented in terms of pressure coefficients, unsteady surface pressure results, turbulence properties of the boundary layer, and corresponding spectral properties of these quantities. The near-field measurement results indicate that introducing a bevel angle yields a region of favorable pressure gradient on the flat-plate and bevel, which accelerates the flow and reduces the size of structures in the boundary layer up until the mid-bevel region, which then decelerates toward the trailing-edge. This change increases the energy content of surface pressure fluctuations as well as the energy content of the velocity field over the trailing-edge and wake, which, in turn, results in an increased radiated far-field noise as supported by beamforming results. Furthermore, at a sufficiently high bevel angle, where pronounced flow separation occurs, the lack of interaction between trailing-edge and shear layer leads to a significant reduction in the radiated far-field noise compared to that of the baseline flat-plate.
Nanophotonic source of quadrature squeezing via self-phase modulation
Authors: Cernansky Robert , Politi Alberto
Published: October 2020

Squeezed light is optical beams with variance below the shot noise level. They are a key resource for quantum technologies based on photons, and they can be used to achieve better precision measurements and improve security in quantum key distribution channels and as a fundamental resource for quantum computation. Here, we demonstrate an integrated source of squeezing based on four-wave mixing that requires a single laser pump, measuring 0.45 dB of broadband quadrature squeezing at high frequencies. We identify and verify that the current results are limited by excess noise produced in the chip and propose ways to reduce it. Calculations suggest that an improvement in the optical properties of the chip achievable with existing technology can develop scalable quantum technologies based on light.
Effect of rotating magnetic field on instabilities of thermocapillary flow in a Czochralski silicon melt pool
Authors: Liu Hao , Zeng Zhong , Qiu Zhouhua , Yin Linmao , Xiao Yao
Published: October 2020

The effect of the rotating magnetic field on the thermocapillary flow instabilities in a Czochralski silicon melt pool was numerically investigated by means of linear stability analysis. We considered three cases, namely, the non-rotating crystal, the crystal rotating in the same direction as the magnetic field (co-rotating crystal), and the crystal rotating in the opposite direction of the magnetic field (counter-rotating crystal). The linear stability analysis results show that the basic flow becomes unstable against two oscillatory instability modes. With the increase of the magnetic Taylor number (Ta), the overall trend of the critical Marangoni number decreases in the cases of a non-rotating crystal and counter-rotating crystal. However, in the case of a co-rotating crystal, the rotating magnetic field significantly improves the flow stability, and an inversion of the propagation direction of the oscillatory wave is observed with the increase of Ta. Energy analyses reveal that the instabilities are hydrodynamic in nature, which are caused by the combination of the strain-induced instability mechanism and the centrifugal instability mechanism, and the rotating magnetic field only provides little energy for the flow instabilities even at large Ta.
Two effective computational schemes for a prototype of an excitable system
Authors: Khater Mostafa M. A. , Park Choonkil , Lu Dianchen
Published: October 2020

In this article, two recent computational schemes [the modified Khater method and the generalized exp−φ(I)–expansion method] are applied to the nonlinear predator–prey system for constructing novel explicit solutions that describe a prototype of an excitable system. Many distinct types of solutions are obtained such as hyperbolic, parabolic, and rational. Moreover, the Hamiltonian system’s characteristics are employed to check the stability of the obtained solutions to show their ability to be applied in various applications. 2D, 3D, and contour plots are sketched to illustrate more physical and dynamical properties of the obtained solutions. Comparing our obtained solutions and that obtained in previous published research papers shows the novelty of our paper. The performance of the two used analytical schemes explains their effectiveness, powerfulness, practicality, and usefulness. In addition, their ability in employing various forms of nonlinear evolution equations is also shown.
Probing the temperature profile across a liquid–vapor interface upon phase change
Authors: Rokoni Arif , Sun Ying
Published: October 2020

Understanding the temperature profile across a liquid–vapor interface in the presence of phase change is essential for the accurate prediction of evaporation, boiling, and condensation. It has been shown experimentally, from non-equilibrium thermodynamics and using molecular dynamics simulations, the existence of an inverted temperature profile across an evaporating liquid–vapor interface, where the vapor-side interface temperature observes the lowest value and the vapor temperature increases away from the interface, opposite to the direction of heat flow. It is worth noting, however, that an inverted temperature profile is not always the case from other experiments and simulations. In this study, we apply non-equilibrium molecular dynamics simulations to systematically study the temperature profile across a liquid–vapor interface during phase change under various heat fluxes in a two-interface setting consisting of both an evaporating and a condensing interface. The calculated vapor temperature shows different characteristics inside the Knudsen layer and in the bulk vapor. In addition, both the direction and magnitude of the vapor temperature gradient, as well as the temperature jump at the liquid–vapor interface, are functions of the applied heat flux. The interfacial entropy generation rate calculated from the vibrational density of state of the interfacial liquid and vapor molecules shows a positive production during evaporation, and the results qualitatively agree with the predictions from non-equilibrium thermodynamics.
Calcium-stannous oxide solid solutions for solar devices
Authors: Taylor Ned Thaddeus , Galbiati Arnaldo , Saavedra Monica , Hepplestone Steven Paul
Published: October 2020

In this study, solid solutions formed of SnO and CaO [termed (Sn:Ca)xO] are explored as potential solar active layers. The results indicate that a ratio of x=7:1 leads to a fundamental direct bandgap of 1.56 eV. In order to promote the transport of excited charge carriers from within the active layer, appropriately aligned hole/electron transport layers need to be identified. To this end, a set of results are presented for the electronic band alignment of (Sn:Ca)7:1O with a selection of oxide transport layers, with and without oxygen vacancies. From this, it is recommended that a CaO/(Sn:Ca)7:1O/TiO2 device shows the most potential for an all-oxide solar cell.
Thickness-dependent electronic transport induced by in situ transformation of point defects in MBE-grown Bi2Te3 thin films
Authors: Zhang Min , Liu Wei , Zhang Cheng , Qiu Junhao , Xie Sen , Hua Fuqiang , Cao Yu , Li Zhi , Xie Hongyao , Uher Ctirad , Tang Xinfeng
Published: October 2020

Interactions among various film growth parameters, such as the substrate temperature (Tsub), film thickness (d), and composition, play a crucial role in controlling the type and density of the intrinsic point defects. In turn, the point defects modulate and control electronic transport properties of Bi2Te3 films. We have grown n-type Bi2Te3 films with different d by molecular beam epitaxy at different Tsub. The formation of point defects was analyzed by a combined use of angle-resolved photoelectron spectroscopy (ARPES) and electronic transport measurements. Two important findings were made: (i) the negatively charged vacancies, VTe··, initially the dominant intrinsic defects, transform gradually during the growth process into positively charged anti-site defects, BiTe′, driven by thermal annealing from a continuously heated substrate; and (ii) from the film's surface into the inner strata of the film, the density of VTe·· decreases while the density of BiTe′ increases, leading to a gradient of vacancies and anti-site defects along the film growth direction. As a result, the electron density in Bi2Te3 films decreases monotonically with increasing d. Moreover, elevating Tsub leads to a more significant in situ annealing effect and an eventual onset of intrinsic excitations that deteriorates electronic transport properties. The thinnest Bi2Te3 film (16 nm) grown at Tsub = 245 °C has the highest electron concentration of 2.03 × 1020 cm−3 and also the maximum room temperature power factor of 1.6 mW m−1 K−2 of all grown epitaxial films. The new insights regarding the defect formation and transformation pave the way for further optimization of electronic transport properties of n-type Bi2Te3-based films.
Modeling of liquid internal energy and heat capacity over a wide pressure–temperature range from first principles
Authors: Proctor J. E.
Published: October 2020

Recently, there have been significant theoretical advances in our understanding of liquids and dense supercritical fluids based on their ability to support high frequency transverse (shear) waves. Here, we have constructed a new computer model using these recent theoretical findings (the phonon theory of liquid thermodynamics) to model liquid internal energy across a wide pressure–temperature range. We have applied it to a number of real liquids in both the subcritical regime and the supercritical regime, in which the liquid state is demarcated by the Frenkel line. Our fitting to experimental data in a wide pressure–temperature range has allowed us to test the new theoretical model with hitherto unprecedented rigor. We have quantified the degree to which the prediction of internal energy and heat capacity is constrained by the different input parameters: the liquid relaxation time (initially obtained from the viscosity), the Debye wavenumber, and the infinite-frequency shear modulus. The model is successfully applied to output the internal energy and heat capacity data for several different fluids (Ar, Ne, N2, and Kr) over a range of densities and temperatures. We find that the predicted heat capacities are extremely sensitive to the values used for the liquid relaxation time. If these are calculated directly from the viscosity data, then, in some cases, changes within the margins of the experimental error in the viscosity data can cause the heat capacity to exhibit a completely different trend as a function of temperature. Our code is computationally inexpensive, and it is available for other researchers to use.
Dynamic excitations of chiral magnetic textures
Authors: Lonsky Martin , Hoffmann Axel
Published: October 2020

Spin eigenexcitations of skyrmions and related chiral magnetic textures have attracted considerable interest over the recent years owing to their strong potential for applications in information processing and microwave devices. The emergence of novel material systems, such as synthetic ferrimagnets and antiferromagnets, the continuing progress in microfabrication and nanofabrication techniques, and the development of more sophisticated characterization methods will undoubtedly provide a further boost to this young particular line of research. This Perspective summarizes the most significant advances during the past years and indicates future directions of both theoretical and experimental works.
Praseodymium cation (Pr+) reactions with H2, D2, and HD: PrH+ bond energy and mechanistic insights from guided ion beam and theoretical studies
Authors: Ghiassee Maryam , Ewigleben Joshua , Armentrout P. B.
Published: October 2020

Guided ion beam tandem mass spectrometry was used to study the reactions of the atomic lanthanide praseodymium cation (Pr+) with H2, D2, and HD as a function of collision energy. Modeling the kinetic-energy-dependent endothermic reactions to form PrH+ (PrD+) yields a 0 K bond dissociation energy (BDE) of 2.10 ± 0.05 eV for PrH+. Quantum chemical calculations were performed for PrH+ at the B3LYP, BHLYP, PBE0, and coupled-cluster with single, double, and perturbative triple levels of theory, and they overestimate the PrH+ experimental BDE by 0.06 –0.28 eV. The branching ratio of the PrH+ and PrD+ products in the HD reaction suggests that the reaction occurs via a direct reaction mechanism with short-lived intermediates. This is consistent with the theoretical calculations for the relaxed potential energy surfaces of PrH2+, where no strongly bound dihydride intermediates were found. The reactivity and PrH+ BDE are compared with previous results for lanthanide metal cations (La+, Ce+, Sm+, Gd+, and Lu+). Periodic trends across the lanthanide series and insights into the role of the electronic configuration on metal-hydride bond strength are discussed.
Impact of secondary donor units on the excited-state properties and thermally activated delayed fluorescence (TADF) efficiency of pentacarbazole-benzonitrile emitters
Authors: Cho Eunkyung , Liu Lei , Coropceanu Veaceslav , Brédas Jean-Luc
Published: October 2020

The performance of organic light-emitting diodes based on thermally activated delayed fluorescence emitters depends on the efficiency of reverse intersystem crossing (RISC) processes, which are promoted by a small energy gap between the lowest singlet (S1) and triplet (T1) excited states and large spin–orbit couplings. Recently, it was proposed that the introduction of secondary donor units into 2,3,4,5,6-penta(9H-carbazol-9-yl)benzonitrile (5CzBN) can significantly increase the mixing between triplet states with charge-transfer (CT) and local-excitation characteristics and consequently increase the spin–orbit couplings. Here, the results of long-range corrected density functional theory calculations show that the main impact on the RISC rates of substituting 5CzBN with secondary donors is due to a decrease in adiabatic singlet–triplet energy gaps and intramolecular reorganization energies rather than to a change in spin–orbit couplings. Our calculations underline that at least two singlet and three triplet excited states contribute to the ISC/RISC processes in 5CzBN and its derivatives. In addition, we find that in all emitters, the lowest singlet excited-state potential energy surface has a double-minimum shape.
Interactions of Charged Particles: Elastic Coulomb Scattering
Authors: Meli Jerome A.
Published: October 2020

On entering matter, charged particles interact with atomic electrons and nuclei via the Coulomb force. Interactions with nuclei are primarily elastic scattering, which is the topic of this chapter. The Rutherford cross section is analyzed, accounting for the shielding of the nuclear charge by atomic electrons. It is shown that heavy charged particles are scattered overwhelmingly through small angles whereas light particles, such as electrons, can experience significant large-angle scattering.
Range of Charged Particles
Authors: Meli Jerome A.
Published: October 2020

This chapter is a study of the range and penetration depth of electrons and heavy charged in matter. Range calculated in the continuous slowing down approximation is compared with the maximum depth of penetration. The method of using measured and calculated range to determine the mean excitation/ionization energy, I, is discussed.
Dose in Charged-particle Beams
Authors: Meli Jerome A.
Published: October 2020

The variation of fluence with depth in charged-particle beams is discussed. Electrons set in motion are classified as primary, secondary, slow, and fast (δ rays). The condition of charged-particle equilibrium of δ rays is described and applied to dose calculations. Restricted stopping is defined and applied to dose calculations where δ ray equilibrium does not exist. Equations are derived for dose in an extended medium, illustrating the Bragg peak for heavy charged particles.
Interactions of Photons: Kinematics
Authors: Meli Jerome A.
Published: October 2020

This chapter discusses the kinematics of the Rayleigh, Compton, photoelectric, and pair production interactions of photons. Expressions are obtained for energy transferred to charged particles that include the energy of Auger electrons resulting from the filling of shell vacancies created during photon interactions with atoms.
Input processing in second language acquisition
Authors: Leeser Michael J. , Keating Gregory D. , Wong Wynne
Published: October 2020

In this chapter, we highlight Bill VanPatten’s numerous contributions to the fields of second language acquisition (SLA) and instructed second language acquisition (ISLA), and to the language teaching profession. We begin with an overview of his major professional achievements, followed by an exploration of his early work and the origins of his model of input processing. We underscore the significant contribution that his model of input processing makes to theory building in SLA and subsequently discuss his pioneering instructional innovation, processing instruction, along with the prolific body of research it has inspired. After briefly noting the importance of his work on acquisition and processing more broadly, we conclude with an overview of the individual chapters included in the volume.
The processing of subject shifts in L2 Spanish
Authors: Johnston Suzanne
Published: October 2020

A vital part of understanding language is linking referring expressions to the appropriate antecedents. In null subject languages like Spanish, person-number inflections on verbs are essential to ensuring the appropriate connections are made. However, second language (L2) learners have limited processing capabilities (VanPatten, 1996, 2015), and may rely on strategies that steer them away from inflections. The current study examines whether first language English/L2 Spanish learners process verb inflections that signal subject shifts or if they prefer to process lexical items (i.e., overt subjects) as predicted by VanPatten’s lexical preference principle. The results of this study indicate that non-natives do not rely on inflections to link antecedents and referring expressions, and that L2 processing is facilitated by overt subject pronouns.
When more is better
Authors: Sagarra Nuria
Published: October 2020

This chapter investigates the role of first language (L1) transfer, second language (L2) proficiency, and working memory (WM) on processing subject-verb number agreement in Spanish. Intermediate and advanced English and Romanian learners of Spanish and Spanish monolinguals completed a WM test and a reading eye-tracking task with sentences with adjacent subject-verb number agreement/disagreement. Results revealed that all groups were sensitive to violations but processed them differently, depending on their L1 (the less morphologically rich, the more reliance on subjects), proficiency (the more advanced, the more reliance on verbs), and WM (the higher the span, the more sensitivity to violations). These findings indicate that higher L1/L2 similarity, L2 proficiency, and WM facilitate L2 verbal morphosyntactic processing.
Let me count the ways it stinks
Authors: Bellamy Kate
Published: October 2020

In this chapter I present a three-way typology of olfactory language in Purepecha, comprising: (i) abstract terms, composed of one of 15 perception roots and the smell-specific ‘spatial couplet’ morphology -k’u and -nti; (ii) descriptive terms whose root refers to another state or event, such as ‘to burn’, plus the spatial couplet morphology; and (iii) an odor source (usually a noun) introduced by a generic verb ‘to be, smell’ ja-. I discuss how different elicitation methods obtained varying proportions of these three types, as well as the distribution of the three generic roots referring to smelling. I then offer an historical perspective, demonstrating how the same three-way typology of smell terms has remained relatively stable over time. Implications for theories of word formation in Purepecha are also considered.
Alternating smell in Modern Hebrew
Authors: Avineri Bar
Published: October 2020

Many studies on perception verbs have dealt with the typology and semantic properties of their clausal complements. Other studies have dealt with the lexical relatedness of different perception verbs with a common sensory modality. Bridging these two views, this work focuses on the Modern Hebrew verb le-hariax ‘to smell’, which alternates in the case-marking of the experiencer and in the type of complement clause, and on the semantic properties which accompany the alternation. The lexical relatedness between words with a common sensory base is expressed through morpho-syntactic means, shared with verbs of other sensory modalities, and these shed light on the linguistic manifestation of the sensory hierarchy and on the contribution of voice alternation within the field of perception.
Smelling over time
Authors: Strik-Lievers Francesca
Published: October 2020

Sensory anthropologists have described societies that, compared to Western ones, attribute to the sense of smell a more prominent cultural role, and linguists are bringing evidence that a higher sociocultural status of smell tends to be reflected in language by a richer and more elaborated olfactory lexicon. Given that the relative prominence of one sense within the sensorium has been shown to vary not only across societies, but also over time, such variation may be expected to have linguistic reflections. This study explores whether and how the olfactory lexicon has changed from Latin to Italian. Is the alleged increased “deodorization” of contemporary Western societies associated with changes in the lexicon? The data show that, contrary to expectations, the overall size of the olfactory lexicon did not undergo appreciable changes. However, it progressively became more oriented toward the negative pole of evaluation (i.e., the expression of unpleasant smells). Implications and possible explanations are discussed in the light of the linguistic and sensory-historical literature.
Multivariate analyses for investigating highly polluted marine ecosystem: The case study of Mar Piccolo (Taranto, South Italy)
Authors: Mali Matilda , Dell'Anna Maria Michela , Mastrorilli Piero , Chiaia Giancarlo , Romanazzi Giuseppe , Damiani Leonardo
Published: October 2020

This study presents the benefits of the application of multivariate techniques for the hazard assessment of a heavily polluted marine ecosystem. The study area, named Mar Piccolo, near Taranto city (Southern Italy), is a shallow marine basin located nearby an industrial compromised area, declared by the national government as Contaminated Site of Environmental Interest (SIN) due to the presence of long-lasting large industrial settlements that have severely impacted the marine environment. Besides the anthropogenic pressures, the marine basin is characterized by high productivity of several species at different trophic levels of the food chain, that confers to the bottom sediments an unusually high organic matter content. The latter is even enhanced by the presence of freshwater springs in the marine basin. The dynamism of the ecosystem demands for advanced evaluation tools for its correct characterisation. Multivariate ANOVA allied by Hierarchical Clustering are applied in this research to provide a readable picture of the quality status of the sediments, aiming at identifying different loading factors and getting insights into their simultaneous effects. The innovative approach adopted circumvents inefficient time-consuming procedures, usually required by the conventional univariate analyses of each parameter selected for sediment characterisation. A comprehensive hazard assessment was possible thanks to a clear graphical representation of the hazard distribution that supported the identification of the hazard controlling factors, confirming the efficiency of the adopted approach. The tools proposed herein can thus be recommended for the decision makers in investigating and interpretation of the quality status of complex polluted marine eco-systems.
Increases in motor unit action potential amplitudes are related to muscle hypertrophy following eight weeks of high‐intensity exercise training in females
Authors: Jenkins Nathaniel D. M. , Rogers Emily. M. , Banks Nile F. , Muddle Tyler W. D. , Colquhoun Ryan J.
Published: October 2020

We examined the motor unit action potential amplitude versus recruitment threshold relationship (MUAPAMP‐RT) as an indicator of MU‐specific hypertrophy following high‐intensity exercise training in females. Participants were assigned to either a high‐intensity exercise (EX, n = 9) or control (CON, n = 18) condition and completed pre‐ (PRE) and post‐testing (POST) during which maximal voluntary isometric leg extension strength (MVIT), vastus lateralis (VL) muscle cross sectional area (mCSA), whole leg skeletal muscle mass (SMMRL), and high‐density surface EMG (HD‐sEMG) signals were recorded from the VL during an isometric ramp contraction at 70% MVIT. The HD‐sEMG signals were decomposed and yielded a MUAPAMP and an absolute (ABS; Nm) and normalized (NORM; %MVIC) RT for each MU. Individual MUAPAMP‐RT slopes and intercepts were calculated for each subject. Changes in the pooled MUAPAMP‐RT relationships for each group were also examined. Finally, relationships among individual changes in slopes of MUAPAMP‐RT and individual changes in mCSA and SMMRL were examined. Training elicited increases in MVIT (+18%), mCSA (+12%), and mean and pooled slopes of MUAPAMP‐RTNORM. The individual changes in slopes of both the MUAPAMP‐RT relationships were moderately to strongly (r = 0.48–0.68) related to changes in mCSA and SMMRL. Eight‐weeks of high‐intensity exercise elicited increases in MUAPAMP‐RT slope in females. Further, the observed change in slope was related to both VL mCSA and SMM of the tested leg. However, changes in slope for the MUAPAMP‐RT relationship were more subdued when MUAPAMP was expressed relative to the absolute versus relative RT.
The mitotic protein NuMA plays a spindle-independent role in nuclear formation and mechanics
Authors: Serra-Marques Andrea , Houtekamer Ronja , Hintzen Dorine , Canty John T. , Yildiz Ahmet , Dumont Sophie
Published: October 2020

Eukaryotic cells typically form a single, round nucleus after mitosis, and failures to do so can compromise genomic integrity. How mammalian cells form such a nucleus remains incompletely understood. NuMA is a spindle protein whose disruption results in nuclear fragmentation. What role NuMA plays in nuclear integrity, and whether its perceived role stems from its spindle function, are unclear. Here, we use live imaging to demonstrate that NuMA plays a spindle-independent role in forming a single, round nucleus. NuMA keeps the decondensing chromosome mass compact at mitotic exit and promotes a mechanically robust nucleus. NuMA’s C terminus binds DNA in vitro and chromosomes in interphase, while its coiled-coil acts as a central regulatory and structural element: it prevents NuMA from binding chromosomes at mitosis, regulates its nuclear mobility, and is essential for nuclear formation. Thus, NuMA plays a structural role over the cell cycle, building and maintaining the spindle and nucleus, two of the cell’s largest structures.
Transcription cofactor GRIP1 differentially affects myeloid cell–driven neuroinflammation and response to IFN-β therapy
Authors: Mimouna Sanda , Rollins David A. , Shibu Gayathri , Tharmalingam Bowranigan , Deochand Dinesh K. , Chen Xi , Oliver David , Chinenov Yurii , Rogatsky Inez
Published: October 2020

Macrophages (MФ) and microglia (MG) are critical in the pathogenesis of multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Glucocorticoids (GCs) and interferon β (IFN-β) are frontline treatments for MS, and disrupting each pathway in mice aggravates EAE. Glucocorticoid receptor–interacting protein 1 (GRIP1) facilitates both GR and type I IFN transcriptional actions; hence, we evaluated the role of GRIP1 in neuroinflammation. Surprisingly, myeloid cell–specific loss of GRIP1 dramatically reduced EAE severity, immune cell infiltration of the CNS, and MG activation and demyelination specifically during the neuroinflammatory phase of the disease, yet also blunted therapeutic properties of IFN-β. MФ/MG transcriptome analyses at the bulk and single-cell levels revealed that GRIP1 deletion attenuated nuclear receptor, inflammatory and, interestingly, type I IFN pathways and promoted the persistence of a homeostatic MG signature. Together, these results uncover the multifaceted function of type I IFN in MS/EAE pathogenesis and therapy, and an unexpectedly permissive role of myeloid cell GRIP1 in neuroinflammation.
Exit from germinal center to become quiescent memory B cells depends on metabolic reprograming and provision of a survival signal
Authors: Inoue Takeshi , Shinnakasu Ryo , Kawai Chie , Ise Wataru , Kawakami Eiryo , Sax Nicolas , Oki Toshihiko , Kitamura Toshio , Yamashita Kazuo , Fukuyama Hidehiro , Kurosaki Tomohiro
Published: October 2020

A still unanswered question is what drives the small fraction of activated germinal center (GC) B cells to become long-lived quiescent memory B cells. We found here that a small population of GC-derived CD38intBcl6hi/intEfnb1+ cells with lower mTORC1 activity favored the memory B cell fate. Constitutively high mTORC1 activity led to defects in formation of the CD38intBcl6hi/intEfnb1+ cells; conversely, decreasing mTORC1 activity resulted in relative enrichment of this memory-prone population over the recycling-prone one. Furthermore, the CD38intBcl6hi/intEfnb1+ cells had higher levels of Bcl2 and surface BCR that, in turn, contributed to their survival and development. We also found that downregulation of Bcl6 resulted in increased expression of both Bcl2 and BCR. Given the positive correlation between the strength of T cell help and mTORC1 activity, our data suggest a model in which weak help from T cells together with provision of an increased survival signal are key for GC B cells to adopt a memory B cell fate.
Enhanced Ferromagnetism of CrI3 Bilayer by Self-Intercalation*
Authors: Guo Yu , Liu Nanshu , Zhao Yanyan , Jiang Xue , Zhou Si , Zhao Jijun
Published: October 2020

Two-dimensional (2D) ferromagnets with high Curie temperature have long been the pursuit for electronic and spintronic applications. CrI3 is a rising star of intrinsic 2D ferromagnets, however, it suffers from weak exchange coupling. Here we propose a general strategy of self-intercalation to achieve enhanced ferromagnetism in bilayer CrI3. We show that filling either Cr or I atoms into the van der Waals gap of stacked and twisted CrI3 bilayers can induce the double exchange effect and significantly strengthen the interlayer ferromagnetic coupling. According to our first-principles calculations, the intercalated native atoms act as covalent bridge between two CrI3 layers and lead to discrepant oxidation states for the Cr atoms. These theoretical results offer a facile route to achieve high-Curie-temperature 2D magnets for device implementation.
Effect of carrier drift-diffusion transport process on thermal quenching of photoluminescence in GaN
Authors: Matys M , Adamowicz B , Kachi T , Hashizume T
Published: October 2020

Thermal quenching of the defect-related photoluminescence (PL) has been widely used to determine the fundamental properties of point defects in GaN such as the activation energy (E

t
) and capture cross section. However, in the present work, we have shown using drift-diffusion modeling and experimental analysis that the thermal quenching of defect-related PL from GaN does not only depend of the defect parameters but also is strongly governed by the carrier drift and diffusion in the depletion region. In particular, we have found that these processes significantly influence the slope of PL thermal quenching and temperature T
0 at which the quenching begins. As a result, E

t
obtained from the Arrhenius plot of the defect-related PL intensity in GaN provides the correct values of the defect activation energy only in the case of low surface state density (

D

0

<

10

11

cm−2eV−1) corresponding to the weak surface band bending. However, in the case of high D
0 giving rise to the significant surface band bending, the E

t
value should be cautiously interpreted because it may not correspond entirely to the real defect activation energy due to the drift-diffusion process. Finally, we have shown that our finding can explain in a coherent manner various anomalous behaviors of PL thermal quenching reported in the literature, such as tunable, abrupt or sample dependent thermal quenching. We believe that our findings can be very interesting for nitride growth technology community and optoelectronic device applications.
Aspects on numerical integration of dislocation surface traction fields for discrete dislocation dynamics FEM coupling: the case of emerging dislocations
Authors: El-Achkar T , Weygand D
Published: October 2020

In discrete dislocation dynamics frameworks for finite samples, the evaluation of surface tractions caused by dislocations requires special attention to capture the contributions of dislocations piercing through the surface. Here we focus on this aspect only, and the convergence of an empirically improved Gauss integration and the Duffy and Duffy distance integration schemes commonly used for 1/r singularities, is investigated for a finite element surface area. It is found, that traction from a dislocation, using singular segment stress fields, can be integrated with an error smaller than 1% with the distance Duffy integration using a total of 48 integration points only. This scheme was tested for a wide range of dislocation Burgers vectors and glide plane orientations with respect to the surface. Furthermore the FEM nodal forces behave smoothly during the motion of exit point of the dislocation (the singular point) to a neighbouring surface element in the mesh.
Simulated mechanical properties of finite-size graphene nanoribbons
Authors: Aparicio E , Tangarife E , Munoz F , Gonzalez R I , Valencia F J , Careglio C , Bringa E M
Published: October 2020

There are many simulation studies of mechanical properties of graphene nanoribbons (GNR), but there is a lack of agreement regarding elastic and plastic behavior. In this paper we aim to analyze mechanical properties of finite-size GNR, including elastic modulus and fracture, as a function of ribbon size. We present classical molecular dynamics simulations for three different empirical potentials which are often used for graphene simulations: AIREBO, REBO-scr and REAXFF. Ribbons with and without H-passivation at the borders are considered, and the effects of strain rate and different boundaries are also explored. We focus on zig-zag GNR, but also include some armchair GNR examples. Results are strongly dependent on the empirical potential employed. Elastic modulus under uniaxial tension can depend on ribbon size, unlike predictions from continuum-scale models and from some atomistic simulations, and fracture strain and progress vary significantly amongst the simulated potentials. Because of that, we have also carried out quasi-static ab-initio simulations for a selected size, and find that the fracture process is not sudden, instead the wave function changes from Blöch states to a strong interaction between localized waves, which decreases continuously with distance. All potentials show good agreement with DFT in the linear elastic regime, but only the REBO-scr potential shows reasonable agreement with DFT both in the nonlinear elastic and fracture regimes. This would allow more reliable simulations of GNRs and GNR-based nanostructures, to help interpreting experimental results and for future technological applications.
Three-dimensionality shapes the dynamics of cortical interconnected to hippocampal networks
Authors: Brofiga Martina , Pisano Marietta , Tedesco Mariateresa , Raiteri Roberto , Massobrio Paolo
Published: October 2020

Objective. The goal of this work is to develop and characterize an innovative experimental framework to design interconnected (i.e. modular) heterogeneous (cortical-hippocampal) neuronal cultures with a three-dimensional (3D) connectivity and to record their electrophysiological activity using micro-electrode arrays (MEAs). Approach. A two-compartment polymeric mask for the segregation of different neuronal populations (cortex and hippocampus) was coupled to the MEA surface. Glass microbeads were used as a scaffold to mimic the 3D brain micro-architecture. Main results. We built a fully functional heterogeneous 3D neuronal network. From an electrophysiological point of view, we found that the heterogeneity induces a global increase of the activity rate, while the 3D connectivity modulates the duration and the organization of the bursting activity. Significance. In vivo, studies of network dynamics and interactions between neuronal populations are often time-consuming, low-throughput, complex, and suffer from reproducibility. On the other hand, most of the commonly used in vitro brain models are too simplified and thus far from the in vivo situation. The achieved results demonstrate the feasibility to build a more realistic and controllable experimental in vitro model of interconnected brain regions on-a-chip whose applications may have impacts on the study of neurological disorders that impair the connectivity between brain areas (e.g. Parkinson disease).
Spatial variation in household consumption-based carbon emission inventories for 1200 Japanese cities
Authors: Kanemoto Keiichiro , Shigetomi Yosuke , Hoang Nguyen Tien , Okuoka Keijiro , Moran Daniel
Published: October 2020

Given that national pledges are likely insufficient to meet Paris greenhouse gas (GHG) reduction targets (Fawcett et al 2015 Science
350), increasingly actors at the city and state level are looking for options on how local government can contribute to reducing GHG emissions. For a typical city only one third to half of their carbon footprint (CF) is emitted within the jurisdiction, while the majority is embodied in goods and services flowing into the city. To support well-informed mitigation efforts, administrators need robust inventories of both direct emissions as well as the supply chain emissions. Here we construct household CF inventories for 1172 Japanese cities using detailed consumer expenditure data and a Japanese domestic multi-regional input-output (MRIO) model. We identify the consumption activities which city policymakers can target to reduce CF. We observe a strong concentration of household CF in a few cities in Japan: 40% of the total Japanese CF is driven by 143 cities. Understanding a city’s consumption-based CF of households in addition to its direct emissions exposes additional policy options for each citizen to contribute to achieving national goals.
Onset of action of inhaled glucocorticoids on bronchial and alveolar nitric oxide output
Authors: Karvonen Tuomas , Sepponen-Lavikko Anna , Holm Kati , Schultz Rüdiger , Moilanen Eeva , Lehtimäki Lauri
Published: October 2020

Fractional exhaled nitric oxide (FENO) is a marker of airway inflammation. Measuring FENO at multiple flow rates enables calculation of NO parameters: bronchial NO output (JawNO), bronchial wall (CawNO) and alveolar (CANO) NO concentrations, and bronchial diffusion factor of NO (DawNO). FENO is known to rapidly reduce after the commencement of inhaled corticosteroid (ICS) treatment. However, little is known on the effect of ICS on the other NO parameters. We assessed (1) the onset of action of ICS treatment on the NO parameters and (2) whether the changes in bronchial NO output are due to changes in bronchial wall NO concentration or diffusion factor. FENO and other NO parameters were measured at baseline and after 1, 3 and 7 d of treatment with inhaled fluticasone propionate 250μg b.i.d. in 23 allergic children with a history of asthma-like symptoms. There was a decrease inJawNO (from 680 (244/1791) (median (1st/3rd quartile)) to 357 (165/753) pl s−1,p< 0.001) and FENO50( from 13.8 (7.5/35) to 8.3 (5.36/17.0) ppb,p< 0.001) in 3 d from the first dose of ICS. Also,CawNO seemed to reduce after 3 d (from 171 (89/328) to 79 (54/157) ppb,p= 0.041), whileDawNO remained unchanged. Furthermore,CANO reduced during the 7 d treatment (from 3.0 (2.0/5.0) to 2.3 (1.9/2.6) ppb,p= 0.004). ICS treatment reduced FENO50andJawNO rapidly and the decline was caused by decreased bronchial wall NO concentration while bronchial NO diffusion factor remained unchanged. These findings suggest thatCawNO could be a more specific marker of airway inflammation and treatment response thanJawNO or FENO50, which are both determined also byDawNO that seems to be resistant to the treatment with ICS.
‘Luminescent carbon nanodots: Current prospects on synthesis, properties and sensing applications’
Authors: Kottam Nagaraju , S P Smrithi
Published: October 2020

‘Nanocarbon science’ ignited interest owing to its substantial scope in biomedicine, energy and environment-beneficial applications. Carbon dots (C-dots), a multi-faceted nanocarbon material, emerged as a homologue to graphene and henceforth geared extensive investigation both on its properties and applications. Eximious properties like excitation-wavelength tunable fluorescence emission, up-converted photoluminescence, photon-induced electron transfer, low cytotoxicity, chiroptical behavior, high chemical and photostability set the ground for astounding applications of carbon dots. Abundant availability of raw ‘green’ precursors complementary to other molecular/graphitic precursors make them environmentally benign, inexpensive and ultimately ‘nanomaterials of the current decade’. This review focuses on the synthesis of carbon dots not only from natural sources but also from other carbonaceous precursors and contemplates the inherent but controversial properties. We also aim to garner the attention of readers to the recent progress achieved by C-dots in one of its prestantious area of applications as nanosensors.
A theoretical model of a wave: an efflux bounce of a solution-particle
Authors: Nemaura T
Published: October 2020

A description of a wave as a bounce is developed. A wave that carries a mass is characterised by a bounce and the mass-spring-damper system. Furthermore, an analogy of a wave/bounce to the mass-spring-damper system is suggested. The efflux bounce considered is responsible for dispersion and is part of the drug transportation wave network in the patient’s blood plasma. A four-dimensional length of tugs (wave) describing the efflux bounce is modelled by a system of differential equations. A single equivalent fourth-order differential equation system is suggested to model the same wave. The two systems are inferred to share a unique characteristic equation. The theoretical models developed are used to infer on the characterisation of the wave comprising of media and boundary components. The media is found to be rigid

(

ω

I

=
0

h

−
1

)

and the boundary as deformable

(

ω

E

=
0.1166154

h

−
1

)

. A loaded structure-wave-particle analogy is proposed.