bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short-term effects of rice straw biochar on hydraulic properties and aggregate stability of an Acrisol
Authors: Parker Nathaniel , Cornelis Wim M. , Frimpong Kwame Agyei , Danso Eric Oppong , Bessah Enoch , Arthur Emmanuel 
Published: September 2021

Biochar application to a structurally poor tropical soil could potentially alter the soil’s aggregate strength and hydraulic properties. However, very few field studies have investigated the impact of biochar on the aggregate strength and hydraulic properties of tropical soils. A field experiment was therefore conducted to investigate the short-term effects of rice straw biochar on soil hydraulic properties and aggregate stability of an Acrisol in Ghana. The biochar was broadcast at rates of 10 t ha−1 and 20 t ha−1 as single applications that were incorporated into the top 20 cm of the soil using a spade and then the soil was levelled using a rake. Field saturated hydraulic conductivity and laboratory-measured soil water retention, aggregate stability and water-repellency were determined 10 months after the biochar application. Biochar increased aggregate stability against fast wetting by up to 33% compared to the control. This implies that biochar might improve the stability of aggregate of an Acrisol against slaking and erosivity of heavy rainfall. However, aggregate stability against slow wetting and mechanical breakdown after pre-wetting were unaffected by the biochar. Biochar did not affect field saturated hydraulic conductivity, water retention characteristics and water-repellency. Further field studies on weathered tropical soils with low native soil organic matter is recommended to elucidate the effect of repeated biochar addition on soil hydraulic and aggregate characteristics.
Looking at redefining sex(uality)
Authors: Urquízar José Iglesias 
Published: September 2021

Abstract
This article examines the dubbing of the 2014 American gay-themed series Looking and its treatment of sexual references into Castilian Spanish with a view to exploring the role of audiovisual translation in the discursive construction of homosexuality. While some scholars have decried a historical tendency in translation to attenuate or even suppress references in connection with non-normative sex, the dubbing of Looking, I claim, amplifies these references by way of two strategies: up-scaling and increased explicitness. Drawing upon Jeremy Munday’s (2012) concept of “evaluation” and on appraisal theory as expounded by Martin and White (2005), I aim at revealing the significance of the translator’s lexicogrammatical selections and how these may alter the semiotic import of the characters and, thus, of a certain portrayal of homosexuality. Additionally, such choices may be indicative of the translator’s own stance towards issues of sexuality. Though the strategies analyzed may appear to perpetuate commonplaces regarding gay sexual experience, they ultimately serve, I argue, as a device to generate a language that goes beyond diluted expressions of homosexuality.
Attitudinal stance towards the anti-extradition bill movement in China Daily and South China Morning Post
Authors: Cao Xiuling , Zhang Danqi , Luo Qianjun 
Published: September 2021

Abstract
Based on Appraisal Theory and critical discourse analysis, this corpus-assisted study examines how China Daily (CD) and South China Morning Post (SCMP) used appraisal resources to express their respective stances towards the anti-extradition bill movement. The results show that both newspapers employed negative resources of Judgement and the predication strategy to convey their stance, but SCMP seemed more refrained in the use of appraisal resources. CD openly stated that any illegal actions should be punished, and SCMP also criticised these actions. Besides, CD emphasized the consequences brought by violence and attributed the breakout of the protests to the opposition camp’s political intention for their own benefit, whereas SCMP highlighted Hong Kongers’ widespread opposition to the bill. These differences in language use and stance might be explained by the different press systems they respectively belong to and related to their respective historical and socio-political contexts.
A high-performance code for EPRL spin foam amplitudes
Authors: Gozzini Francesco 
Published: September 2021

AbstractWe presentsl2cfoam-next, a high-performance software library for computing Lorentzian EPRL spin foam amplitudes. The library improves on previous codes by many orders of magnitude in single-core performance, can be parallelized on a large number of CPUs and on the GPU, and can be used interactively. We describe the techniques used in the code and provide many usage examples. As first applications, we usesl2cfoam-nextto complete the numerical test of the Lorentzian single-vertex asymptotics and to confirm the presence of the ‘flatness problem’ of spin foam models in the BF and EPRL cases.
Minimizing magnetic fields of the low-noise MnZn ferrite magnetic shield for atomic magnetometer
Authors: Yang Ke , Lu Jixi , Wang Zixuan , Sun Bowen , Ma Yanning , Wang Yaoguo , Han Bangcheng 
Published: September 2021

Abstract
Several modern precision measurements require a low-noise magnetic shield composed of a MnZn ferrite shield and a multilayer µ-metal shield. However, the residual magnetic field and gradient reduce the performance of the low-noise magnetic shield. An appropriate demagnetization operation is crucial for obtaining a lower residual magnetic field and gradient. This study proposes an improved demagnetization scheme in which the toroidal coil and the solenoidal coil are employed simultaneously, while the ferrite and µ-metal shield layers are wound separately. This allows for a residual field below 0.6 nT and a gradient lower than 0.5 nT cm−1 to be obtained along all three axes within ±20 mm at the center, which is significantly lower than the results published in previous studies. The low-noise magnetic shield used in this study composed of a MnZn ferrite shield with an inner diameter of 112 mm, an outer diameter of 140 mm, and a height of 225 mm, and a five-layer µ-metal shield. This study considerably improves the performance of the low-noise magnetic shields. The proposed scheme can increase the sensitivity of the spin-exchange-relaxation-free atomic magnetometer by approximately 1 fT Hz-1/2. This study can help apply the low-noise magnetic shield in various fields more conveniently, such as low-field nuclear magnetic resonance detection, atomic gyroscope, and in cutting-edge physics research.
The status and future of direct nuclear reaction measurements for stellar burning
Authors: Aliotta M , Buompane R , Couder M , Couture A , deBoer R J , Formicola A , Gialanella L , Glorius J , Imbriani G , Junker M , Langer C , Lennarz A , Litvinov Yu A , Liu W-P , Lugaro M , Matei C , Meisel Z , Piersanti L , Reifarth R , Robertson D , Simon A , Straniero O , Tumino A , Wiescher M , Xu Y 
Published: September 2021

Abstract
The study of stellar burning began just over 100 years ago. Nonetheless, we do not yet have a detailed picture of the nucleosynthesis within stars and how nucleosynthesis impacts stellar structure and the remnants of stellar evolution. Achieving this understanding will require precise direct measurements of the nuclear reactions involved. This report summarizes the status of direct measurements for stellar burning, focusing on developments of the last couple of decades, and offering a prospectus of near-future developments.
Relation between spin current and spin torque in Rashba ferromagnets
Authors: Jiang Peng , Ma Zhongshui 
Published: September 2021

Abstract
We establish a brief relation between spin current and spin torque, including spin–orbit torque and spin transfer torque in 2D Rashba ferromagnets with nonuniform magnetic texture. Both electrically and thermally induced charge, heat, and spin current are investigated by the Luttinger’s mechanical method, and we derive the contributions of magnetization corresponding to the thermal spin current and the thermal spin torque. The novel transport currents are also found in this paper when the interplay between spin–orbit coupling and nonuniform magnetic texture is taken into account.
Molecular dynamics simulations of screw dislocation mobility in bcc Nb
Authors: Zotov Nikolay , Grabowski Blazej 
Published: September 2021

Abstract
The screw dislocation mobility in bcc Nb has been studied by molecular dynamics (MD) simulations at different strain rates and temperatures using an embedded-atom method (EAM) potential. Static properties of the screw dislocation, as determined with the EAM potential, are in agreement with previous density-functional-theory calculations. The elementary slip plane of the screw dislocation remains (110) for all studied strain rates (in the range 6.3 × 107–6.3 × 109 s−1) and temperatures (5 to 550 K). However, the consecutive cross-slip on different symmetry-equivalent (110) planes leads to an effective glide on (112) planes. It is demonstrated that the screw dislocation trajectories, velocities and waviness of the screw dislocation depend on the crystallographic indices, (110) or (112), of the maximum resolved shear stress plane. The waiting time for the start of the screw dislocation motion increases exponentially with decreasing strain rate, substantiating the necessity to apply in future accelerated MD techniques in order to compare with macroscopic stress-strain experiments.
Development of data-driven spd tight-binding models of Fe—parameterisation based on QSGW and DFT calculations including information about higher-order elastic constants
Authors: Barzdajn Bartosz , Garrett Alexander M , Whiting Thomas M , Race Christopher P 
Published: September 2021

Abstract
Quantum-mechanical (QM) simulations, thanks to their predictive power, can provide significant insights into the nature and dynamics of defects such as vacancies, dislocations and grain boundaries. These considerations are essential in the context of the development of reliable, inexpensive and environmentally friendly alloys. However, despite significant progress in computer performance, QM simulations of defects are still extremely time-consuming with ab-initio/non-parametric methods. The two-centre Slater–Koster (SK) tight-binding (TB) models can achieve significant computational efficiency and provide an interpretable picture of the electronic structure. In some cases, this makes TB a compelling alternative to models based on abstraction of the electronic structure, such as the embedded atom model. The biggest challenge in the implementation of the SK method is the estimation of the optimal and transferable parameters that are used to construct the Hamiltonian matrix. In this paper, we will present results of the development of a data-driven framework, following the classical approach of adjusting parameters in order to recreate properties that can be measured or estimated using ab-initio or non-parametric methods. Distinct features include incorporation of data from QSGW (quasi-particle self-consistent GW approximation) calculations, as well as consideration of higher-order elastic constants. Furthermore, we provide a description of the optimisation procedure, omitted in many publications, including the design stage. We also apply modern optimisation techniques that allow us to minimise constraints on the parameter space. In summary, this paper introduces some methodological improvements to the semi-empirical approach while addressing associated challenges and advantages.
Breakdown prediction of ion source at EAST-NBI using neural network
Authors: Wang Jinxin , Wang Na , Liu Zhimin , Zhao Yuanzhe , Xie Yahong , Xie Yuanlai 
Published: September 2021

Abstract
The designed neural networks are trained to appraise the risk of ion sources breakdown events in the neutral beam injector (NBI) experimental device using several offline diagnostic signals as inputs. A saliency analysis proves the reasonableness of the chosen inputs, some of which are helpful to improve the network performance. The experimental tests that were carried out refer to data collected from successfully-terminated and breakdown-terminated shots performed during three years of experimental advanced superconducting tokamak NBI experiments, from 2016 to 2019. Results show that it is very possible to develop a predictor base on neural network that intervenes well in advance to avoid ion sources breakdown or mitigate its effects during the beam extraction in the high-power and long-pulse mode.
Thermal confinement and transport in spherical tokamaks: a review
Authors: Kaye S M , Connor J W , Roach C M 
Published: September 2021

Abstract
In this paper, we review the thermal plasma confinement and transport properties observed and predicted in low aspect ratio tokamaks, or spherical tokamaks (STs), which can depart significantly from those observed at higher aspect ratio. In particular, thermal energy confinement scalings show a strong, near linear dependence of energy confinement time on toroidal magnetic field, while the dependence on plasma current is more modest, the opposite of what is seen at higher aspect ratio. STs have revealed a very strong improvement in normalized confinement with decreasing collisionality, much stronger than at higher aspect ratio, which bodes well for an ST-based fusion pilot plant should this trend continue at an even lower collisionality than has already been accessed. These differences arise because of fundamental differences in transport in STs due to the more extreme toroidicity (i.e. reduced region of bad curvature), and to the relatively larger

E
r

×
B

shearing rates, both of which can suppress electrostatic drift wave instabilities at both ion and electron gyroradius scales. In addition, electromagnetic effects are much stronger in STs because they operate at high β

T
. Gyrokinetic (GK) studies, coupled with low- and high-k turbulence measurements, have shed light on the underlying physics controlling transport. At lower β

T
, both ion- and electron-scale electrostatic drift turbulence may be responsible for transport. At higher βT
, microtearing, kinetic ballooning, and hybrid trapped electron/kinetic ballooning modes increasingly play a role, and they have a much stronger impact in the core of ST plasmas than at higher aspect ratio. Flow shear affects the balance between ion- and electron-scale modes. Non-linear GK simulations find regimes where the electron heat flux decreases with decreasing collisionality, consistent with the experimental global normalized confinement scaling. The ST is unique in that the relatively low toroidal magnetic field allows for localized measurements of electron-scale turbulence, and this coupled with turbulence measurements at ion-scales has facilitated detailed comparisons with GK simulations. These data have provided compelling evidence for the presence of ion temperature gradient and electron temperature gradient turbulence in some plasmas, and direct experimental support for the impact of experimental actuators like rotation shear, density gradient and magnetic shear on turbulence and transport.
On the use of CFD to obtain head loss coefficients in hydraulic systems and its application to liquid metal MHD flows in nuclear fusion reactor blankets
Authors: Suarez Daniel , Mas de les Valls Elisabet , Batet Lluis 
Published: September 2021

Abstract
When an incompressible fluid flows through a contraction in a conduit, the increase in the kinetic energy of the fluid is accompanied by a pressure drop. This pressure drop is not to be assimilated with head loss. If downstream the fluid encounters an expansion in the conduit, the energy conversion will take place in the opposite way. Therefore, when a geometrical singularity is analysed to assess its contribution to the pumping power requirements of the system, the whole mechanical energy transfer of the fluid in the singularity has to be taken into account, and not only the pressure variation. The first part of the present work establishes a method to obtain head loss coefficients in geometric singularities of hydrodynamic circuits using the results of computational fluid dynamics (CFD) calculations. These coefficients are of interest when modelling the whole system with a 1D system code, for instance. In the second part of the article, the method is applied to a more complex case, involving magnetohydrodynamic (MHD) phenomena. Thus, a prototypical channel singularity in a liquid metal circuit subject to a magnetic field is analysed. The layout is representative of a case that could be found in the liquid metal blankets to be used in nuclear fusion reactors. The influence of the MHD phenomena is studied and the differences with a purely hydrodynamic case are pointed out. The MHD analyses have been done in the Marconi High Performance Computing facility, using 48 cores, each case needing between one and two weeks to complete.
Phase transitions in virology
Authors: Solé Ricard , Sardanyés Josep , Elena Santiago F 
Published: September 2021

Abstract
Viruses have established relationships with almost every other living organism on Earth and at all levels of biological organization: from other viruses up to entire ecosystems. In most cases, they peacefully coexist with their hosts, but in most relevant cases, they parasitize them and induce diseases and pandemics, such as the AIDS and the most recent avian influenza and COVID-19 pandemic events, causing a huge impact on health, society, and economy. Viruses play an essential role in shaping the eco-evolutionary dynamics of their hosts, and have been also involved in some of the major evolutionary innovations either by working as vectors of genetic information or by being themselves coopted by the host into their genomes. Viruses can be studied at different levels of biological organization, from the molecular mechanisms of genome replication, gene expression and encapsidation, to global pandemics. All these levels are different and yet connected through the presence of threshold conditions allowing for the formation of a capsid, the loss of genetic information or epidemic spreading. These thresholds, as occurs with temperature separating phases in a liquid, define sharp qualitative types of behaviour. These phase transitions are very well known in physics. They have been studied by means of simple, but powerful models able to capture their essential properties, allowing us to better understand them. Can the physics of phase transitions be an inspiration for our understanding of viral dynamics at different scales? Here we review well-known mathematical models of transition phenomena in virology. We suggest that the advantages of abstract, simplified pictures used in physics are also the key to properly understanding the origins and evolution of complexity in viruses. By means of several examples, we explore this multilevel landscape and how minimal models provide deep insights into a diverse array of problems. The relevance of these transitions in connecting dynamical patterns across scales and their evolutionary and clinical implications are outlined.
Si tunnel junctions obtained by proximity rapid thermal diffusion for tandem photovoltaic cells
Authors: Li Xiao , Fave Alain , Lemiti Mustapha 
Published: September 2021

Abstract
Low-resistance c-Si Esaki tunnel junctions (TJ) can be applied in two-terminal Si-based tandem solar cells to electrically connect two sub-cells. Proximity rapid thermal diffusion (PRTD) is an economical and facile method to fabricate the Si tunnel junctions with a damage-free surface. The p++/n++ Si TJ on (111)-oriented c-Si wafer produced by combining PRTD and photovoltaic industrial techniques is reported in this work. The adjustment of the n++ emitter by a two-step rapid thermal annealing effectively facilitates the realization of the p++/n++ TJ. The peak current density of a tunnel diode based on this TJ is within the range 140–192 A cm−2 with a peak to valley current ratio of 1.9–3.2. Such a p++/n++ TJ is implemented in III–V nanowires (NWs) on Si tandem solar cells. Despite the defectuosity of the NWs array, we demonstrate that an increase of the open-circuit voltage is observed compared with the sole single-junction Si solar cell. This kind of TJ can also be integrated with other top cell materials such as perovskites and copper indium gallium selenide. Low-cost and high-efficiency c-Si based tandem solar cells might be produced with the application of Si TJs obtained by PRTD.
Monte Carlo evaluation of GaN THz Gunn diodes
Authors: Lee Wen Zhao , Ong Duu Sheng , Choo Kan Yeep , Yilmazoglu Oktay , Hartnagel Hans L 
Published: September 2021

Abstract
The performances of GaN-based Gunn diodes have been studied extensively for more than two decades, however, the diverging electron drift velocity characteristics employed in these studies merit a review of the potential of GaN Gunn diodes as THz sources. A self-consistent analytical-band Monte Carlo (MC) model capable of reproducing the electron drift velocity characteristics of GaN predicted theoretically by the first-principles full band MC model is used in this work to evaluate systematically the performance of GaN Gunn diodes in transit time mode. The optimal fundamental frequency of a sustainable current oscillation under a DC bias is determined as a function of the length of its transit region. The MC model predicts a GaN Gunn diode with a transit length of 500 nm capable of operating at frequencies up to 625 GHz with an estimated output power of 3.0 W. An MC model takes into account the effect of defects in order to replicate the much lower electron drift velocity characteristics derived from experimental work and predicts THz signal generation of 2.5 W at highest sustainable operating frequency of 326 GHz in a Gunn diode with a transit length of 700 nm.
Optimizing the establishment of bean and maize varieties in tropical environments
Authors: Andrade J A , Mateus M , Cadima J F , Abreu F G 
Published: September 2021

Abstract
The successful establishment of any crop is the initial indication of its productivity. Optimizing the establishment of a crop implies ensuring generalized, fast and concentrated emergence. This work studies optimal temperature ranges, under non-limiting water conditions, for both germination and emergence of two bean (Phaseolus vulgaris L.) varieties (catarina and ervilha) and two maize (Zea mays L.) varieties (matuba and sam3).
Experiments used a thermogradient plate. Petri dishes were used for germination experiments. Emergence experiments were performed in aluminium containers filled with packed portions of a sandy loam clay textured soil. Size, speed and spread of both germination and emergence were measured at different temperatures by Cu-CuNi thermocouples.
Thermal ranges with optimal counts of both germination and emergence [To1
sz, To2
sz] were identified using a flattened bell curve function. Speed was maximized for either germination or emergence over thermal ranges [To1
sp, To2
sp] defined using the plateau model to relate either germination or emergence rates with temperature. Ranges along which the spread of both germination and emergence are nearly minimized [To1
sd, To2
sd] were identified with the aid of even-degree polynomials. The intersection of all three thermal ranges gave rise to optimal temperature ranges [To1, To2] for germination (OTRG) of the four varieties in study and for emergence (OTRE) of three of them. In general, the lower thermal limit of OTRg was determined by speed (To1 = To1
sp) and the upper thermal limit by size (To2 = To2
sz). OTRe begins at To1
sp for ervilha and sam3 and at To1
sd for catarina and ends at To2
sz for catarina and at To2
sd for the others. The endpoints and length of both the OTRG and OTRE were also found to be crop-dependent. Thus, farmers can choose between crops and optimize their establishment. The identification of these parameters may also be useful in assessing weather forecasts and for warning systems and agro-climatic zoning. The influence of the substrate used in each experiment was also discussed.