bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of mixing thermodynamic properties on the Soret effect
Authors: Kiyosawa Tomohiro , Shimizu Masahiro , Matsuoka Jun , Nakashima Kento , Sato Kenzo , Nishi Masayuki , Shimotsuma Yasuhiko , Miura Kiyotaka
Published: October 2022

We demonstrate that the modified Kempers model, a recently developed theoretical model for the Soret effect in oxide melts, is applicable for predicting the composition dependence of the Soret coefficient in three binary molecular liquids with negative enthalpies of mixing. We compared the theoretical and experimental values for water/ethanol, water/methanol, water/ethylene glycol, water/acetone, and benzene/n-heptane mixtures. In water/ethanol, water/methanol, and water/ethylene glycol, which have negative enthalpies of mixing across the entire mole fraction range, the modified Kempers model successfully predicts the sign change of the Soret coefficient with high accuracy, whereas, in water/acetone and benzene/n-heptane, which have composition ranges with positive enthalpies of mixing, it cannot predict the sign change of the Soret coefficient. These results suggest that the model is applicable in composition ranges with negative enthalpies of mixing and provides a framework for predicting and understanding the Soret effect from the equilibrium thermodynamic properties of mixing, such as the partial molar volume, partial molar enthalpy of mixing, and chemical potential.
A novel theoretical model of gas–solid two-phase flow mixed dielectric discharge
Authors: Shi Zhipeng , Kang Yongqiang , Zhang Jialin , Li Shuaibing , Li Hongwei
Published: October 2022

A theoretical physical model of gas–solid two-phase flow mixed dielectric discharge in a uniform field based on Townsend's discharge theory is presented. This model extends the classical Townsend's theory to be applicable to the quantitative analysis of dielectric discharge questions related to gas–solid two-phase flow environments, reveals the influence mechanism of flowing gases and solid-phase particles on discharge, and provides a theoretical basis for expanding the application of discharge plasma technology in various fields. In the model, based on the basic physical process of gas discharge and our previous studies, the effects of the attraction and obstructive factors of solid-phase particles on the number density of electrons or ions and the local space electric field in the inception and development of gas discharge were taken into account. On this basis, the analytical expression of the breakdown voltage in a gas–solid two-phase flow mixed dielectric is obtained, Paschen's law of gas breakdown is modified, and Townsend's breakdown criterion for gas–solid two-phase flow situation is proposed. It is shown that the breakdown voltage of the gas–solid two-phase flow mixed dielectric decreases with increasing gas flow velocity. The gas flow velocity is the main factor affecting the variation trend of the breakdown voltage. The concentration and size of solid-phase particles determine the values of breakdown voltage. The breakdown voltage of the smaller size and higher concentration of solid-phase particles is greater, which has a stronger suppression effect on the discharge.
Is opt-out enrolment acceptable for low-risk digital health services?
Authors: Dobson Rosie , Uri Amanda , Whittaker Robyn , Evison Karen , Umali Elaine , McRobbie Hayden
Published: October 2022

Introduction Digital health programmes not only complement existing services, but have the potential to reach populations that existing services are not reaching. Many of these services require people to opt-in to receive them, which presents significant barriers to access. An alternative is to make low-risk digital services opt-out, ensuring appropriate members of the target audience are signed up for a service unless they select to not receive it. Aim This study aimed to investigate how changing enrolment in a low-risk digital health programme from opt-in to opt-out would impact on enrolment and dropout rates. Methods This study involved the retrospective analysis of registration data from txtpēpi, a maternal and child health text-message programme. System-recorded data from enrolments during a 12-month period were obtained. In the first 6 months, users had to opt-in to the service (Period 1), but in the following 6 months, an opt-out process was implemented (Period 2). Results There was a 77% increase in enrolments in Period 2 (n = 113) compared to Period 1 (n = 64) and no significant change in the proportion of enrolments of Māori between time periods (P = 0.508). There was no significant difference in withdrawal rates between time periods at either 2 weeks (5% vs 6%, P = 0.676) or 1 month (9% vs 9%, P = 0.907). Discussion This study has shown switching from an opt-in to an opt-out option resulted in an increase in enrolments in an mHealth programme, but had no impact on withdrawals. This indicates that employing opt-out enrolment for low-risk evidence-based interventions is acceptable and a potential way to make these services more accessible.
Molecular convergence by differential domain acquisition is a hallmark of chromosomal passenger complex evolution
Authors: Komaki Shinichiro , Tromer Eelco C. , De Jaeger Geert , De Winne Nancy , Heese Maren , Schnittger Arp
Published: October 2022

The chromosomal passenger complex (CPC) is a heterotetrameric regulator of eukaryotic cell division, consisting of an Aurora-type kinase and a scaffold built of INCENP, Borealin, and Survivin. While most CPC components are conserved across eukaryotes, orthologs of the chromatin reader Survivin have previously only been found in animals and fungi, raising the question of how its essential role is carried out in other eukaryotes. By characterizing proteins that bind to the
Arabidopsis
Borealin ortholog, we identified BOREALIN RELATED INTERACTOR 1 and 2 (BORI1 and BORI2) as redundant Survivin-like proteins in the context of the CPC in plants. Loss of BORI function is lethal and a reduced expression of
BORI
s causes severe developmental defects. Similar to Survivin, we find that the BORIs bind to phosphorylated histone H3, relevant for correct CPC association with chromatin. However, this interaction is not mediated by a BIR domain as in previously recognized Survivin orthologs but by an FHA domain, a widely conserved phosphate-binding module. We find that the unifying criterion of Survivin-type proteins is a helix that facilitates complex formation with the other two scaffold components and that the addition of a phosphate-binding domain, necessary for concentration at the inner centromere, evolved in parallel in different eukaryotic groups. Using sensitive similarity searches, we find conservation of this helical domain between animals and plants and identify the missing CPC component in most eukaryotic supergroups. Interestingly, we also detect Survivin orthologs without a defined phosphate-binding domain, likely reflecting the situation in the last eukaryotic common ancestor.
Biosynthesis of iridoid sex pheromones in aphids
Authors: Köllner Tobias G. , David Anja , Luck Katrin , Beran Franziska , Kunert Grit , Zhou Jing-Jiang , Caputi Lorenzo , O’Connor Sarah E.
Published: October 2022

Iridoid monoterpenes, widely distributed in plants and insects, have many ecological functions. While the biosynthesis of iridoids has been extensively studied in plants, little is known about how insects synthesize these natural products. Here, we elucidated the biosynthesis of the iridoids
cis
-
trans-
nepetalactol and
cis
-
trans-
nepetalactone in the pea aphid
Acyrthosiphon pisum
(Harris), where they act as sex pheromones. The exclusive production of iridoids in hind legs of sexual female aphids allowed us to identify iridoid genes by searching for genes specifically expressed in this tissue. Biochemical characterization of candidate enzymes revealed that the iridoid pathway in aphids proceeds through the same sequence of intermediates as described for plants. The six identified aphid enzymes are unrelated to their counterparts in plants, conclusively demonstrating an independent evolution of the entire iridoid pathway in plants and insects. In contrast to the plant pathway, at least three of the aphid iridoid enzymes are likely membrane bound. We demonstrated that a lipid environment facilitates the cyclization of a reactive enol intermediate to the iridoid cyclopentanoid-pyran scaffold in vitro, suggesting that membranes are an essential component of the aphid iridoid pathway. Altogether, our discovery of this complex insect metabolic pathway establishes the genetic and biochemical basis for the formation of iridoid sex pheromones in aphids, and this discovery also serves as a foundation for understanding the convergent evolution of complex metabolic pathways between kingdoms.
The photoprotection mechanism in the black–brown pigment eumelanin
Authors: Ilina Aleksandra , Thorn Karen E. , Hume Paul A. , Wagner Isabella , Tamming Ronnie R. , Sutton Joshua J. , Gordon Keith C. , Andreassend Sarah K. , Chen Kai , Hodgkiss Justin M.
Published: October 2022

The natural black–brown pigment eumelanin protects humans from high-energy UV photons by absorbing and rapidly dissipating their energy before proteins and DNA are damaged. The extremely weak fluorescence of eumelanin points toward nonradiative relaxation on the timescale of picoseconds or shorter. However, the extreme chemical and physical complexity of eumelanin masks its photoprotection mechanism. We sought to determine the electronic and structural relaxation pathways in eumelanin using three complementary ultrafast optical spectroscopy methods: fluorescence, transient absorption, and stimulated Raman spectroscopies. We show that photoexcitation of chromophores across the UV–visible spectrum rapidly generates a distribution of visible excitation energies via ultrafast internal conversion among neighboring coupled chromophores, and then all these excitations relax on a timescale of ∼4 ps without transferring their energy to other chromophores. Moreover, these picosecond dynamics are shared by the monomeric building block, 5,6-dihydroxyindole-2-carboxylic acid. Through a series of solvent and pH-dependent measurements complemented by quantum chemical modeling, we show that these ultrafast dynamics are consistent with the partial excited-state proton transfer from the catechol hydroxy groups to the solvent. The use of this multispectroscopic approach allows the minimal functional unit in eumelanin and the role of exciton coupling and excited-state proton transfer to be determined, and ultimately reveals the mechanism of photoprotection in eumelanin. This knowledge has potential for use in the design of new soft optical components and organic sunscreens.
Towards a corpus-based description of speech-gesture units of meaning
Authors: Chen Yaoyao , Adolphs Svenja
Published: October 2022

The theories and methods in corpus linguistics (CL) have had an impact on numerous areas in applied linguistics.
However, the interface between CL and multimodal speech-gesture studies remains underexplored. One fundamental question is whether
it is possible, and even appropriate, to apply the theories and paradigms established based on textual data to multimodal data. To
explore this, we examine how CL can assist investigating lexico-grammatical patterns of speech co-occurring with a recurrent
gesture (i.e. the circular gesture). Sinclair’s (1996) unit of meaning model is used to
describe the co-gestural speech patterns. The study draws on a subset of the Nottingham Multimodal Corpus, in which 570 instances
of circular gestures and their co-occurring speech are identified and analysed. We argue that Sinclair’s unit of meaning model can
be extended to include speech-gesture patterns, and that those descriptions enable a more nuanced understanding of meaning in
context.
The intricate dialectics of iconization and structuration
Authors: Sonesson Göran
Published: October 2022

The distinction between primary and secondary iconic signs, which I first made with regard to pictures, has been applied by other scholars to language, gesture, and music. Taking stock of this process, it has become necessary to clarify the distinction, insisting on the fact that secondary iconicity is not conventionality, but a kind of iconicity which is in itself not sufficient to define a meaning, but needs to be supplemented by other means, such as a label or a system of oppositions. We have shown this to be the case earlier, when considering what Arnheim termed ‘droodles’, but we will see that it also applies to language and music.
Iconicity as a key epistemic source of change in the self
Authors: Andacht Fernando
Published: October 2022

In this text, the phenomenological categorial analysis at the basis of Peircean semiotic is used to explore the working of iconic signs and their relationship to the self as an ongoing interpretative process as well as to the manifold of identities that human beings adopt in the different circumstances they go through. A film was chosen to describe the relevance of iconicity for the evolving self-interpretative process that serves to adapt us to life changes. The plot of The Lives of Others (Das Leben der Anderen, von Donnersmarck 2006) brings out in exemplary fashion the epistemic function of iconicity to account for spontaneity as the origin of the new and unexpected in the lifeworld. Peirce’s triadic analysis of the imagination elucidates how change is introduced even in a most authoritarian sociopolitical system, whose main goal is to avoid the irruption of the freewheeling possibilism of iconicity.
Indexicality and iconization in Mocking Spanish
Authors: Piluso Francesco
Published: October 2022

When we speak Mock Spanish, the relevant aspects of this practice are usually activated and acknowledged in terms of indexical connections to specific stereotypes regarding the Spanish language and its speakers. However, when we speak about “Mock Spanish”, in order to deconstruct such an indexical ideological presupposition and entailment, it is important to focus on the iconic features of this language, or better, of this linguistic practice. The aim of this paper is to investigate the complex network of sign-relationships that inform the linguistic and ideological phenomenon of Mock Spanish. The work by Jane Hill (1998, 2005) will be the main reference used to highlight the indexical meanings of this language and their ideological presupposition. Exploring its entailments, additionally, requires integrating the indexical aspect with the semiotic process of ‘iconization’ (Irvine and Gal 2000). Iconization between Spanish speakers and language – ideologically naturalized through an intertextual series of Mock Spanish – is a key element in the construction (and deconstruction) of the negative racial stereotypes of Spanish speakers and, inversely, of the White ‘hegemony’ in the public space. In conclusion, an overall understanding of Mock Spanish as a ‘metapragmatics’ (Silverstein 1993) will be useful to further analyze the issue of language ideology.
This is not a pipe
Authors: Moreno Cabrera Juan Carlos
Published: October 2022

A significant part of René Magritte’s pictorial work is devoted to the challenging relationships between images and written words. In this paper, I will look into two series of Magritte’s language paintings addressing these relationships: The Treachery of Images (also known as This is not a pipe) and The Interpretation of Dreams. In both series, painted images of written words and phrases are juxtaposed to painted images of objects in order to show that words and images should not be taken as the real objects they depict or refer to. I will show that, in addition to this obvious interpretation, there are much more interesting and challenging issues concerning the iconicity of the relationships between written words and the images depicting the objects denoted by them in Magritte’s paintings. To illustrate this point, I will elaborate on the calligram approach to the Treachery of Images proposed by Michel Foucault and Douglas Hofstadter by exploring the subliminal iconic relationships between the image of the pipe and the shape of the letters in the painted sentence (ceci n’est pas une pipe ‘this is not a pipe’). In addition, I will show that this analysis can be extended to the paintings entitled The Interpretation of Dreams. These analyses might shed a new light on these enigmatic works of art.
Image superimposition in signed language discourse and in motion pictures
Authors: Müller Anke
Published: October 2022

Both film and signed languages are media that make use of iconicity and employ motion images for communicative and narrative purposes. This paper focuses on simultaneously presented images that occur in film for example as double exposures and in signed languages as simultaneous constructions. While film and signed languages differ in many ways with respect to iconicity, they can be compared with respect to the way simultaneously presented motion images relate to each other. Superimpositions are defined as a simultaneous view on two or more scenes or as giving two different simultaneous representations of one scene. They serve as a means of dense information packaging. While superimpositions strongly differ in their appearance in film and signed discourse, they exhibit some similarities of structure and functions. They exploit the iconicity of spatial relations emerging in the graphic spatial dimension. Their function is to express a spatial, intentional or temporal connection between two scenes or aspects of one scene, for example the intentional relation between a cognitive activity as seen in the face of a person and the object or content of that cognitive activity.
Where frozen signs reclaim iconic ground
Authors: Konrad Reiner , Langer Gabriele , Müller Anke , Wähl Sabrina
Published: October 2022

Sign Languages provide ways to create iconically motivated signs, that is, signs whose meaning is directly or indirectly connected to an underlying mental image expressed by the depictive elements of the sign’s form. While signs can be created and used to depict and therefore show what is meant, not all iconically motivated signs are used in this way. Signs of the established lexicon have meanings that are fixed by convention, although their form may be iconically motivated. In signing discourse established signs are used to denote objects, persons, situations or actions (function of ‘telling’). Once the context has thus been clarified iconic signs can be used in the function of ‘showing’. For this purpose, signers often create new, context-fitting iconic signs (‘productive signs’). However, iconically motivated established signs can also be used for showing by re-activating their underlying image and modifying their form. When analyzing data it sometimes is difficult to decide whether the sign should be classified as a modified established sign (‘iconic modification’) or as a productive sign. This decision is relevant for annotation (token-type-matching) as well as for the corpus-based lexicographic description of a sign’s usage. In this paper we discuss sequences of a telling sign followed by a showing sign found in the DGS Corpus. We suggest some criteria for the classification and explain where we would draw the line between iconic modification and productive signs.
Recurring iconic mapping patterns within and across verb types in German Sign Language
Authors: Oomen Marloes
Published: October 2022

Many sign languages around the world have the same tripartite verb classification system based on agreement properties, and it has previously been observed that this system is at least partially semantically grounded. In this article, the extent to which iconicity plays a mediating role in this relationship between verb type and verb semantics is investigated through the identification of recurring iconic mappings across verb forms in German Sign Language (DGS). The aim is to establish which event properties are commonly iconically represented in DGS verb forms, and which of those can additionally be associated with verbs of a specific type. The results indicate that across types, handshape is associated with semantic transitivity, while the location and movement specifications of a verb form are associated with verb type. The results thus contribute toward our understanding of the role of iconicity in the relation between verb semantics and verb type in DGS and, by extension, other sign languages with similar verb type systems.
Lexical choices in Early Modern English devotional prose
Authors: Smith Jeremy J.
Published: October 2022

Religious controversy in English has always been marked by ideologically charged lexicons. Developments in the analysis of machine-readable corpora have enabled more robust conclusions to be drawn about the nature of these vocabularies, relating particular usages to particular confessional orientations. In this paper, part of a long-term research project on the history of English religious vocabulary, an attempt is made to identify “keywords” characteristic of presbyterian, puritan and high Anglican communities of practice within the Church of England. In addition, the paper addresses some methodological and theoretical issues involved in such research, relating to the practice of historical pragmatics.
The Bilingual Code-Switching Profile (BCSP)
Authors: Olson Daniel J.
Published: October 2022

Significant variation exists in bilinguals’ experiences with code-switching, from dense code-switching in multiple interactional contexts to minimal switching. Although recent research has demonstrated that a bilingual’s experience with code-switching is a crucial factor for determining both linguistic and cognitive behaviors, there currently is no commonly accepted method of measuring of a bilingual’s code-switching practices. Responding to this need, this paper presents a new tool to assess a bilingual’s experience and engagement with code-switching – the Bilingual Code-Switching Profile (BCSP) – and assesses its validity and reliability. The BCSP incorporates a multifaceted conceptualization of code-switching experience, drawing on previous research in bilingual proficiency, and addresses a bilingual’s code-switching history, use, proficiency, and attitudes. To assess the validity and reliability of the BCSP, Spanish–English bilinguals (N = 454) from a wide range of ages, ethnic backgrounds, national origins, and language dominance profiles completed the questionnaire. Results of an exploratory factor analysis and intraclass correlation on test-retest data (N = 248) demonstrate that the BCSP is a valid and reliable method of assessing a bilingual’s code-switching profile. The BCSP can be easily and practically incorporated into future research on bilinguals to provide a systematic measure of an individual’s code-switching profile.
Heat Treatment, Microstructure and Corrosion Relationship on 316L SS Produced by AM
Authors: Özer Gökhan
Published: October 2022

In this study, 316L stainless steel (SS) samples produced with standard parameters using the Additive Manufacturing method were heat treated with different parameters, and the effects of heat treatment on the microstructure, phase changes, hardness, porosity, and corrosion of the material were examined in detail. The results showed that the as-built microstructure of 316L stainless steel material produced by Additive Manufacturing deteriorated as the heat treatment temperature increased and the hardness decreased. The corrosion resistance of the material increased. The best corrosion resistance was obtained from heat treatment at 1150°C for 2 h.
Scaling Laws of Heat Flux Width in the HL-2A Closed Divertor Tokamak
Authors: Yan Longwen , Gao Jinming , Miao Xianggan , Huang Zhihui , Wu Na , Chen Wenjin , Wu Ting , Wang Weice , Liu Liang , He Xiaoxue , Yi Kaiyang , He Yu , Nie Lin , Shi Zhongbing , Zhong Wulv
Published: October 2022

The scaling law of divertor heat flux width is one of the key topics of magnetic confinement fusion, which is almost inversely proportional to the poloidal magnetic field on some opened divertor tokamaks. This work focuses on the scaling laws of the closed divertor heat flux width in the HL-2A tokamak under different discharge conditions, such as the Ohmic, L- and H-modes. The results indicate that there are basic similarities of the scaling laws of the heat flux width between the opened and closed divertors. However, a larger spreading width in the private flux region is found, which is relevant to a small expansion factor of the magnetic flux in the closed divertor.
Role of resistance forces in Galileo’s experiments
Authors: Breiland W G
Published: October 2022

We apply fluid resistance and rolling resistance analysis to the free fall and projectile experiments described in Galileo Galilei’s 1638 Dialogues Concerning Two New Sciences (Discorsi), and his unpublished folio 116v experiment in the Codex 72 collection. Both air resistance and rolling resistance affect the horizontal projection distance in the folio 116v experiment. Newton’s second law and the two combined resistance forces can quantitatively explain Galileo’s observations. The analysis is also applied to replication experiments made by Naylor in 1974. Quantitative agreement is achieved. Resistance forces remove a small discrepancy between observed and theoretical horizontal projectile distances that is present when air resistance and rolling resistance are ignored. The result is significant because it shows that, contrary to prior studies, resistance forces cannot be ignored when one models the folio 116v experiment. Air drag forces due to acceleration (added mass and Basset history) are negligible, but quasi-steady drag and Magnus lift are not. This exercise provides an historical perspective to the description of basic body motion: constant acceleration, uniformly increased velocity, constant inertial motion, and decomposition of two-dimensional motion into orthogonal coordinates. It also serves to give specific examples of significant ‘real-world’ effects, such as steady drag, added mass, Basset history, rolling resistance, spin drag, and Magnus lift that complicate what appears to be a simple experiment. Finally, it shows that a quantitative test of a seemingly obvious assumption can yield new insights.
Theoretical and numerical studies of inverse source problem for the linear parabolic equation with sparse boundary measurements
Authors: Lin Guang , Zhang Zecheng , Zhang Zhidong
Published: October 2022

We consider the inverse source problem in the parabolic equation, where the unknown source possesses the semi-discrete formulation. Theoretically, we prove that the flux data from any nonempty open subset of the boundary can uniquely determine the semi-discrete source. This means the observed area can be extremely small, and that is the reason we call it sparse boundary data. For the numerical reconstruction, we formulate the problem from the Bayesian sequential prediction perspective and conduct the numerical examples which estimate the space-time-dependent source state by state. To better demonstrate the method’s performance, we solve two common multiscale problems from two models with a long source sequence. The numerical results illustrate that the inversion is accurate and efficient.
Nonstationary iterated Tikhonov regularization: convergence analysis via Hölder stability
Authors: Mittal Gaurav , Giri Ankik Kumar
Published: October 2022

In this paper, we study the nonstationary iterated Tikhonov regularization method (NITRM) proposed by Jin and Zhong (2014 Numer. Math.
127 485–513) to solve the inverse problems, where the inverse mapping fulfills a Hölder stability estimate. The iterates of NITRM are defined through certain minimization problems in the settings of Banach spaces. In order to study the various important characteristics of the sought solution, we consider the non-smooth uniformly convex penalty terms in the minimization problems. In the case of noisy data, we terminate the method via a discrepancy principle and show the strong convergence of the iterates as well as the convergence with respect to the Bregman distance. For noise free data, we show the convergence of the iterates to the sought solution. Additionally, we derive the convergence rates of NITRM method for both the noisy and noise free data that are missing from the literature. In order to derive the convergence rates, we solely utilize the Hölder stability of the inverse mapping that opposes the standard analysis which requires a source condition as well as a nonlinearity estimate to be satisfied by the inverse mapping. Finally, we discuss three numerical examples to show the validity of our results.
Recovery of release cloud from laser shock-loaded graphite and hydrocarbon targets: in search of diamonds
Authors: Schuster A K , Voigt K , Klemmed B , Hartley N J , Lütgert J , Zhang M , Bähtz C , Benad A , Brabetz C , Cowan T , Döppner T , Erb D J , Eychmüller A , Facsko S , Falcone R W , Fletcher L B , Frydrych S , Ganzenmüller G C , Gericke D O , Glenzer S H , Grenzer J , Helbig U , Hiermaier S , Hübner R , Laso Garcia A , Lee H J , MacDonald M J , McBride E E , Neumayer P , Pak A , Pelka A , Prencipe I , Prosvetov A , Rack A , Ravasio A , Redmer R , Reemts D , Rödel M , Schoelmerich M , Schumacher D , Tomut M , Turner S J , Saunders A M , Sun P , Vorberger J , Zettl A , Kraus D
Published: October 2022

This work presents first insights into the dynamics of free-surface release clouds from dynamically compressed polystyrene and pyrolytic graphite at pressures up to 200 GPa, where they transform into diamond or lonsdaleite, respectively. These ejecta clouds are released into either vacuum or various types of catcher systems, and are monitored with high-speed recordings (frame rates up to 10 MHz). Molecular dynamics simulations are used to give insights to the rate of diamond preservation throughout the free expansion and the catcher impact process, highlighting the challenges of diamond retrieval. Raman spectroscopy data show graphitic signatures on a catcher plate confirming that the shock-compressed PS is transformed. First electron microscopy analyses of solid catcher plates yield an outstanding number of different spherical-like objects in the size range between ten(s) up to hundreds of nanometres, which are one type of two potential diamond candidates identified. The origin of some objects can unambiguously be assigned, while the history of others remains speculative.
Normally-OFF AlGaN/GaN-based HEMTs with decreasingly graded AlGaN cap layer
Authors: Xing Zhanyong , Zhang Haochen , Sun Yue , Yang Lei , Hu Kunpeng , Liang Kun , Wang Dawei , Fu Houqiang , Sun Haiding
Published: October 2022

In this work, an enhancement-mode (E-mode) AlGaN/GaN-based high-electron-mobility transistor (HEMT) with a graded AlGaN cap layer (GACL) is proposed and numerically studied by Silvaco technology computer-aided design. The GACL is designed with a decreasingly graded Al composition x along [0001] direction and the initial x is smaller than the Al composition of the Al0.2Ga0.8N barrier layer (BL). This GACL scheme can simultaneously produce high-concentration polarization-induced holes and negative net polarization charges at the GACL/BL interface. This can facilitate the separation of the conduction band (E
C) and Fermi level (E
F) at the 2DEG channel and therefore benefit the normally-OFF operation of the device. The optimized graded-AlGaN-gated metal-semiconductor HEMT can achieve a large threshold voltage of 4 V. Furthermore, we demonstrated that shortening the gate length on the GACL and inserting an oxide layer between the gate and GACL can be both effective to suppress gate leakage current, enhance gate voltage swing, and improve on-state drain current of the device. These numerical investigations can provide insights into the physical mechanisms and structural innovations of the E-mode GaN-based HEMTs in the future.
Propagation dynamics and interaction of multiple streamers at and above adjacent dielectric pellets in a packed bed plasma reactor
Authors: Mujahid Zaka-ul-Islam , Korolov Ihor , Liu Yue , Mussenbrock Thomas , Schulze Julian
Published: October 2022

The propagation and interaction between surface streamers propagating over dielectric pellets in a packed bed plasma reactor operated in Helium are studied using phase and space resolved optical emission spectroscopy and simulations. Such a discharge is known to generate cathode directed positive streamers in the gas phase at the positions of minimum electrode gap followed by surface streamers that propagate along the dielectric surface. By systematically varying the gap between neighboring dielectric pellets, we observe that a larger gap between adjacent dielectric pellets enhances plasma emission near the contact points of the dielectric structures. In agreement with the experiment, the simulation results reveal that the gap influences the attraction of streamers towards adjacent dielectric pellets via polarization of the surface material and the repulsion induced by nearby streamers. For a smaller gap, the streamer propagation changes from along the surface to propagation through the volume and back to surface propagation due to a combination of repulsion between adjacent streamers, polarization of adjacent dielectric surfaces, as well as acceleration of electrons from the volume towards the streamer head. For a wider gap, the streamer propagates along the surface, but repulsion by neighboring streamers increases the offset between the streamers. The streamer achieves a higher speed near the contact point earlier in the absence of an adjacent streamer, which indicates the role of mutual streamer interaction via repulsion.
Kinetics of rapid growth and melting of Al50Ni50 alloying crystals: phase field theory versus atomistic simulations revisited
*
Authors: Rozas Roberto E , Ankudinov Vladimir , Galenko Peter K
Published: October 2022

A revised study of the growth and melting of crystals in congruently melting Al50Ni50 alloy is carried out by molecular dynamics (MDs) and phase field (PF) methods. An embedded atom method (EAM) potential of Purja Pun and Mishin (2009 Phil. Mag. 89 3245) is used to estimate the material’s properties (density, enthalpy, and self-diffusion) of the B2 crystalline and liquid phases of the alloy. Using the same EAM potential, the melting temperature, density, and diffusion coefficient become well comparable with experimental data in contrast with previous works where other potentials were used. In the new revision of MD data, the kinetics of melting and solidification are quantitatively evaluated by the ‘crystal-liquid interface velocity–undercooling’ relationship exhibiting the well-known bell-shaped kinetic curve. The traveling wave solution of the kinetic PF model as well as the hodograph equation of the solid-liquid interface quantitatively describe the ‘velocity–undercooling’ relationship obtained in the MD simulation in the whole range of investigated temperatures for melting and growth of Al50Ni50 crystals.
An enhanced multiscale generation and depth-perceptual loss-based super-resolution network for prostate ultrasound images
Authors: Lu Xu , Wu Shaohui , Xiao Zhiwei , Huang Xiongwei
Published: October 2022

Computer-aided diagnosis of prostate ultrasound images is gradually being combined with deep learning to help detect and treat diseases. However, ultrasound images of the prostate have problems such as low resolution and unbalanced categories. In addition, the current image classification algorithms have difficulty with classification network performance due to insufficient data volume. To solve these problems, inspired by CycleGAN, we propose an enhanced multiscale generation and depth-perceptual loss-based super-resolution (SR) network for prostate ultrasound images (EGDL-CycleGAN). We study and improve the generative network and perceptual loss of CycleGAN. In this work we achieve multiscale feature extraction through an improved generator, and utilize full-scale skip connections between encoder and decoder to capture fine-grained details and coarse-grained semantics at full scale. This effectively improves the performance of the generative network and makes the reconstruction effect better. We also use the residual structure for deep extraction of features to obtain perceptual loss, and add this to the network loss function for training the model. This enables the model to learn the global and local differences between the real and generated images. This approach pays more attention to the edge information and spatial information of the image, and provides relevant spatial information feedback to the generator to improve the generator’s ability to perceive consistent super-resolution. The method can enhance the prostate ultrasound image dataset and provide rich images for the next step in intelligence-assisted classification and diagnosis of prostate cancer ultrasound images. The evaluation of peak signal-to-noise ratio/structural similarity and visual effects against the benchmark of our datasets illustrates that our proposed approach is effective and superior to the bicubic classic image SR reconstruction algorithm, the SRGAN perception-driven method and the CycleGAN method applied to ultrasound images. In addition, the method of using the original dataset combined with the SR reconstruction image dataset can effectively improve the accuracy of the classification network in intelligence-assisted classification diagnosis of prostate cancer ultrasound images. In EfficientNetV2 the accuracy is improved from 0.843 to 0.867 and in Swin Transformer the accuracy is improved from 0.893 to 0.917.
Real-time VUV radiation monitoring in low-pressure hydrogen plasma based on fluorescence of sodium salicylate
Authors: Han Jonggu , Park Woojin , Mauchauffé Rodolphe , Lim Keon-Hee , Lee Gwang-Ho , In Seongjin , Park Jitae , Kang Chansoo , Moon Se Youn
Published: October 2022

Recently, vacuum ultra-violet (VUV) radiation emitted from plasmas has been of particular interest in semiconductor device fabrication because of the effects of its high-energy photons, such as induced damage or curing on low-k materials. Due to the difficulty of implementing conventional spectroscopic methods to monitor VUV radiation with high accuracy and time resolution in current plasma processing equipment, novel monitoring methods must be investigated. Therefore, in this work, we developed a compact VUV radiation monitoring system based on a scintillator, i.e. sodium salicylate (NaSal), for real-time VUV measurements. Compared to conventional VUV spectrometers, the system shows considerable implementation potential thanks to its compact size, higher detection accuracy and high time resolution. VUV radiation emitted by continuous and pulsed hydrogen plasmas generated at low pressure was investigated using the developed system. Using various filters, we were able to compare the VUV photon intensity in different wavelength ranges. It was found that the VUV photon intensity between 115 and 250 nm was about 2.5 times higher than in the region below 115 nm due to intense Lyman-α and molecular radiation, such as Lyman and Werner bands observed in low-pressure hydrogen plasmas.
Research on main bearing life prediction of direct-drive wind turbine based on digital twin technology
Authors: Zhao Wentao , Zhang Chao , Wang Jianguo , Peyrano Oscar García , Gu Fengshou , Wang Shuai , Lv Da
Published: October 2022

Large and expensive mechanical equipment such as wind turbines generally has limited fault datasets from real-world operations for digital model development. This often leads to poor accuracy in implementing a model based on the life prediction. To address this data shortage issue in developing deep learning models, a remaining useful life prediction approach is proposed in this paper, which combines digital twin technology with transfer learning theory and the embedded convolutional long short-term memory (CLSTM) extended model. First, the main bearing of a direct-drive wind turbine is mapped to the digital world using digital twin technology, allowing the fault datasets of main bearings to be generated and thereby ensuring the model is trained sufficiently with a balanced dataset. The CLSTM network then performs convolutional operations on input-to-state and state-to-state transitions, thereby integrating the time dependence and time-frequency characteristics of the data. Meanwhile, transfer learning is used to transfer the trained model to the wind field for real-world fault diagnostics and the life prediction of the main bearings. Finally, the approach is applied to predict the life of the main bearings, and is also compared with other methods of similar type. The results verified that the proposed approach can effectively overcome the low data density of large equipment, greatly improving the accuracy of life prediction.
Molecular dynamics analysis of the low-temperature shock behavior of the CoCrFeMnNi high-entropy alloy
Authors: Chen Xiang , Li Shuang , Tang Xiao , Lu Sheng , Zhao Yang , Fu Tao , Peng Xianghe
Published: October 2022

This study presents a non-equilibrium molecular dynamics simulation of the shock compression of a [1

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0]-oriented CoCrFeMnNi high-entropy alloy (HEA) at 77 K. The effects of different impact velocities on the mechanical properties were investigated in detail, as well as the changes in atomic microstructure and the formation of defects and dislocations under impact loading. In addition, the role of voids in the CoCrFeMnNi HEA was investigated. The results showed that with an increase in impact velocity, the average values of the atomic velocity, temperature, and stress increase. The phenomenon of double-wave separation of the elastic and plastic waves was apparent, and when the loading velocity increased, the propagation velocities of the elastic and plastic waves also increased incrementally. The change in the atomic microstructure and generation of dislocation defects further revealed the effect of different impact velocities on the CoCrFeMnNi HEA. The degree of change in the phase structure was positively correlated with the magnitude of the impact velocity; however, the number of dislocations and defects first increased to a maximum and then decreased with the increase in impact velocity. In addition, the void structure had almost no effect on the phase change of the HEA when subjected to impact loading, whereas the effect on dislocation defects was more pronounced.
Metal to insulator transition, colossal Seebeck coefficient and large violation of Wiedemann–Franz law in nanoscale granular nickel
Authors: Sharma Vikash , Okram Gunadhor Singh , Kuo Yung-Kang
Published: October 2022

We report on the electrical and thermal transport properties of nickel nanoparticles with crystallite size from 23.1 ± 0.3 to 1.3 ± 0.3 nm. These nanoparticles show a systematic metal to insulator transition with the change in the conduction type from n- to p-type, colossal Seebeck coefficient of 1.87 ± 0.07 mV K−1, and ultralow thermal conductivity of 0.52 ± 0.05 W m−1 K−1 at 300 K as the crystallite size drops. The electrical resistivity analysis reveals a dramatic change in the electronic excitation spectrum indicating the opening of an energy gap, and cotunneling and Coulomb blockade of the charge carriers. Seebeck coefficient shows transport energy degradation of charge carriers as transport level moves away from the Fermi level with decrease in crystallite size. The Lorenz number rising to about four orders of magnitude in the metallic regimes with decrease in crystallite size, showing a large violation of the Wiedemann–Franz law in these compacted nickel nanoparticles. Such an observation provides the compelling confirmation for unconventional quasiparticle dynamics where the transport of charge and heat is independent of each other. Therefore, such nanoparticles provide an intriguing platform to tune the charge and heat transport, which may be useful for thermoelectrics and heat dissipation in nanocrystal array-based electronics.
An image analysis method for quantifying precision and disorder in nanofabricated photonic structures
Authors: Carfagno Henry S , García Pedro David , Doty Matthew F
Published: October 2022

Disorder is an essential parameter in photonic systems and devices, influencing phenomena such as the robustness of topological photonic states and the Anderson localization of modes in waveguides. We develop and demonstrate a method for both analyzing and visualizing positional, size, and shape disorder in periodic structures such as photonic crystals. This analysis method shows selectivity for disorder type and sensitivity to disorder down to less than 1%. We show that the method can be applied to more complex shapes such as those used in topological photonics. The method provides a powerful tool for process development and quality control, including analyzing the precision of E-beam lithography before patterns are transferred; quantifying the precision limits of lithography, deposition, or etch processes; and studying the intentional displacement of individual objects within otherwise periodic arrays.
Application of a simple DNA damage model developed for electrons to proton irradiation
Authors: Matsuya Yusuke , Kai Takeshi , Parisi Alessio , Yoshii Yuji , Sato Tatsuhiko
Published: October 2022

Proton beam therapy allows irradiating tumor volumes with reduced side effects on normal tissues with respect to conventional x-ray radiotherapy. Biological effects such as cell killing after proton beam irradiations depend on the proton kinetic energy, which is intrinsically related to early DNA damage induction. As such, DNA damage estimation based on Monte Carlo simulations is a research topic of worldwide interest. Such simulation is a mean of investigating the mechanisms of DNA strand break formations. However, past modellings considering chemical processes and DNA structures require long calculation times. Particle and heavy ion transport system (PHITS) is one of the general-purpose Monte Carlo codes that can simulate track structure of protons, meanwhile cannot handle radical dynamics simulation in liquid water. It also includes a simple model enabling the efficient estimation of DNA damage yields only from the spatial distribution of ionizations and excitations without DNA geometry, which was originally developed for electron track-structure simulations. In this study, we investigated the potential application of the model to protons without any modification. The yields of single-strand breaks, double-strand breaks (DSBs) and the complex DSBs were assessed as functions of the proton kinetic energy. The PHITS-based estimation showed that the DSB yields increased as the linear energy transfer (LET) increased, and reproduced the experimental and simulated yields of various DNA damage types induced by protons with LET up to about 30 keV μm−1. These results suggest that the current DNA damage model implemented in PHITS is sufficient for estimating DNA lesion yields induced after protons irradiation except at very low energies (below 1 MeV). This model contributes to evaluating early biological impacts in radiation therapy.