bluuebunny/crossref_metadata_2025 huggingface dataset:
Wavelet method optimised by ant colony algorithm used for extracting stable and unstable signals in intelligent substations
Authors: Jiang Tianyan , Yang Xiao , Yang Yuan , Chen Xi , Bi Maoqiang , Chen Jianfei
Published: July 2021

Partial discharge (PD) signals are an important index to evaluate the operation state of intelligent substations. The correct distinction of PD pulse and interference pulse has become a challenging task. Because of the noise and the low signal‐to‐noise ratio, the stable signals become non‐stationary. The selection of a wavelet basis, the selection rule of threshold λ and the design of the threshold function are the key factors affecting the final denoising effect. Therefore, an enhanced ant colony optimisition wavelet (ACOW) algorithm was applied to find the global optimal threshold through the continuous derivative threshold function and the ant colony optimisation (ACO) algorithm. At the same time the efficiency of adaptive search calculation, was also significantly improved. The method of the ACOW algorithm was compared with the soft wavelet method, gradient‐based wavelet method and the genetic optimisation wavelet (GOW) method. Using these four methods to denoise four typical signals, different mean square errors (MSE), magnitude errors (ME) and time costs were obtained. Interestingly, the results show that the ACOW method can achieve the minimum MSE and has less time cost. It generates significantly smaller waveform distortion than the other three threshold estimation methods. In addition, the high efficiency and good quality of the output signals are beneficial to the diagnosis of local discharge signals in intelligent substations.
Singly and doubly deuterated formaldehyde in massive star-forming regions
Authors: Zahorecz S. , Jimenez-Serra I. , Testi L. , Immer K. , Fontani F. , Caselli P. , Wang K. , Onishi T.
Published: July 2021

Context. Deuterated molecules are good tracers of the evolutionary stage of star-forming cores. During the star formation process, deuterated molecules are expected to be enhanced in cold, dense pre-stellar cores and to deplete after protostellar birth.

Aims. In this paper, we study the deuteration fraction of formaldehyde in high-mass star-forming cores at different evolutionary stages to investigate whether the deuteration fraction of formaldehyde can be used as an evolutionary tracer.

Methods. Using the APEX SEPIA Band 5 receiver, we extended our pilot study of the J = 3 →2 rotational lines of HDCO and D2CO to eleven high-mass star-forming regions that host objects at different evolutionary stages. High-resolution follow-up observations of eight objects in ALMA Band 6 were performed to reveal the size of the H2CO emission and to give an estimate of the deuteration fractions HDCO/H2CO and D2CO/HDCO at scales of ~6″ (0.04–0.15 pc at the distance of our targets).

Results. Our observations show that singly and doubly deuterated H2CO are detected towards high-mass protostellar objects (HMPOs) and ultracompact H II regions (UC H II regions), and the deuteration fraction of H2CO is also found to decrease by an order of magnitude from the earlier HMPO phases to the latest evolutionary stage (UC H II), from ~0.13 to ~0.01. We have not detected HDCO and D2CO emission from the youngest sources (i.e. high-mass starless cores or HMSCs).

Conclusions. Our extended study supports the results of the previous pilot study: the deuteration fraction of formaldehyde decreases with the evolutionary stage, but higher sensitivity observations are needed to provide more stringent constraints on the D/H ratio during the HMSC phase. The calculated upper limits for the HMSC sources are high, so the trend between HMSC and HMPO phases cannot be constrained.
Exploring the nature of ambiguous merging systems: GW190425 in low latency
Authors: Barbieri C. , Salafia O. S. , Colpi M. , Ghirlanda G. , Perego A.
Published: July 2021

GW190425 is a recently discovered gravitational wave (GW) source whose individual binary components are consistent with being neutron stars (NSs). However, the source-frame chirp mass 1.44 ± 0.02 M⊙ is larger than that of any double NS system known as yet, and it falls in the ‘ambiguous’ interval for which the presence of a black hole (BH) cannot be ruled out from the GW signal analysis alone. GW190425 might host an NS and a light BH, with a mass in the so-called lower mass gap. No electromagnetic (EM) counterpart has been associated with this event, due to the poorly informative sky localisation and larger distance compared to GW170817. We construct kilonova (KN) light curve models for GW190425, in both the double NS and BH-NS scenarios, considering two equations of state (EoSs) consistent with current constraints from GW170817 and the NICER results, including BH spin effects, and testing different fitting formulae for the ejecta mass. According to our models, the putative presence of a light BH in GW190425 would have produced a brighter KN emission compared to the double NS case, ideally leading to the possibility of distinguishing the nature of the binary. However, depending on the adopted fitting formula for the ejecta, the feasibility of this distinction might depend on the EoS and on the BH spin. Concerning candidate counterparts of GW190425, classified later on as supernovae, our models could have been used to discard two transients detected in their early r-band evolution, as these fall outside the phase space encompassed by our models. We conclude that combining the chirp mass and distance information from the GW signal with a library of KN light curves can help in identifying the EM counterpart early on, and we stress that the low-latency release of the chirp mass in this interval of ambiguous values can be vital for successful EM follow-ups.
Bridging hybrid- and full-kinetic models with Landau-fluid electrons
Authors: Finelli F. , Cerri S. S. , Califano F. , Pucci F. , Laveder D. , Lapenta G. , Passot T.
Published: July 2021

Context. Magnetic reconnection plays a fundamental role in plasma dynamics under many different conditions, from space and astrophysical environments to laboratory devices. High-resolution in situ measurements from space missions allow naturally occurring reconnection processes to be studied in great detail. Alongside direct measurements, numerical simulations play a key role in the investigation of the fundamental physics underlying magnetic reconnection, also providing a testing ground for current models and theory. The choice of an adequate plasma model to be employed in numerical simulations, while also compromising with computational cost, is crucial for efficiently addressing the problem under study.

Aims. We consider a new plasma model that includes a refined electron response within the “hybrid-kinetic framework” (fully kinetic protons and fluid electrons). The extent to which this new model can reproduce a full-kinetic description of 2D reconnection, with particular focus on its robustness during the nonlinear stage, is evaluated.

Methods. We perform 2D simulations of magnetic reconnection with moderate guide field by means of three different plasma models: (i) a hybrid-Vlasov-Maxwell model with isotropic, isothermal electrons, (ii) a hybrid-Vlasov-Landau-fluid (HVLF) model where an anisotropic electron fluid is equipped with a Landau-fluid closure, and (iii) a full-kinetic model.

Results. When compared to the full-kinetic case, the HVLF model effectively reproduces the main features of magnetic reconnection, as well as several aspects of the associated electron microphysics and its feedback onto proton dynamics. This includes the global evolution of magnetic reconnection and the local physics occurring within the so-called electron-diffusion region, as well as the evolution of species’ pressure anisotropy. In particular, anisotropy-driven instabilities (such as fire-hose, mirror, and cyclotron instabilities) play a relevant role in regulating electrons’ anisotropy during the nonlinear stage of magnetic reconnection. As expected, the HVLF model captures all these features, except for the electron-cyclotron instability.
Investigating point sources in MWC 758 with SPHERE
Authors: Boccaletti A. , Pantin E. , Ménard F. , Galicher R. , Langlois M. , Benisty M. , Gratton R. , Chauvin G. , Ginski C. , Lagrange A.-M. , Zurlo A. , Biller B. , Bonavita M. , Bonnefoy M. , Brown-Sevilla S. , Cantalloube F. , Desidera S. , D’Orazi V. , Feldt M. , Hagelberg J. , Lazzoni C. , Mesa D. , Meyer M. , Perrot C. , Vigan A. , Sauvage J.-F. , Ramos J. , Rousset G. , Magnard Y.
Published: July 2021

Context. Spiral arms in protoplanetary disks could be shown to be the manifestation of density waves launched by protoplanets and propagating in the gaseous component of the disk. At least two point sources have been identified in the L band in the MWC 758 system as planetary mass object candidates.

Aims. We used VLT/SPHERE to search for counterparts of these candidates in the H and K bands, and to characterize the morphology of the spiral arms.

Methods. The data were processed with now-standard techniques in high-contrast imaging to determine the limits of detection, and to compare them to the luminosity derived from L band observations.

Results. In considering the evolutionary, atmospheric, and opacity models we were not able to confirm the two former detections of point sources performed in the L band. In addition, the analysis of the spiral arms from a dynamical point of view does not support the hypothesis that these candidates comprise the origin of the spirals.

Conclusions. Deeper observations and longer timescales will be required to identify the actual source of the spiral arms in MWC 758.
Spin density wave – metal (superconductor) competition:
A phase segregation scenario
Authors: Pasquier C. , Héritier M. , Jérome D.
Published: July 2021

We present a model comparing the free energy of a phase exhibiting a segregation between spin density
wave (SDW) and metallic domains (eventually superconducting domains) and the free energy of homogeneous
phases which explains the findings observed recently in (TMTSF)2PF6. The dispersion relation of this
quasi-one-dimensional organic conductor is linearized around the Fermi level. Deviations from perfect nesting which
stabilizes the SDW state are described by a unique parameter t$'_b$, this parameter can be the pressure as well.
Optical response of the sliding charge density wave in K0.3MoO3
Authors: Gorshunov B. , Haffner S. , Dressel M. , Lommel B. , Ritter F. , Assmus W.
Published: July 2021

We measured the optical response of K0.3MoO3 along the b-axis in the CDW ground state and found two
optical modes in the millimeter wave and far-infrared range which we assign to the amplitude and the phason mode
located at 2 cm-1 and 10 cm-1 respectively. Applying an external electric field, which exceeds the threshold of
non-linear conductivity, an new mode appears around 4 cm-1 which exhibits an additional fine structure. Ths mode may
be related to the sliding charge density condensate which interacts with the underlying lattice. We observe no change
in the phason mode under bias and only a small loss of spectral weight in the amplitude mode.
Competing SDW phases and quantum oscillations in (TMTSF)2ClO4
in magnetic field
Authors: Radic D. , Bjelis A. , Zanchi D.
Published: July 2021

We propose a new approach for studying spin density waves (SDW) in the Bechgaard salt (TMTSF)2ClO4
where lattice is dimerized in transverse direction due to anion ordering. The SDW response is calculated in the matrix
formulation that rigorously treats the hybridization of inter-band and intra-band SDW correlations. Since the
dimerization gap is large, of the order of transverse bandwidth, we also develop an exact treatment of magnetic
breakdown in the external magnetic field. The obtained results agree with the experimental data on the fast
magneto-resistance oscillations. Experimentally found 260T rapid oscillations and the characteristic Tc dependance on magnetic
field of relaxed material are fitted with our results for anion potential of the order of interchain hopping.
Dynamics of charge density wave phase-slips
in mesoscopic samples
Authors: Artemenko S. N.
Published: July 2021

Theoretical model of current conversion from normal to collective current in mesoscopic samples
of CDW conductors is presented. The current conversion is described in terms of phase slips (PS) induced
by strain of the CDW and stimulated by thermal fluctuations. Kernels of PS situated near contacts
are surrounded by long-range perturbations of the CDW phase. If spacing between contacts is shorter
than decaying length of these perturbations then temporal evolution of PS at different contacts becomes
correlated, and PS voltage decreases with spacing between the contacts decreasing. The results are in
qualitative agreement with experimental study of current conversion in submicron NbSe3 wires.
Coexistence of superconductivity and spin density wave orderings
in Bechgaard and Fabre salts
Authors: Pasquier C. , Auban-Senzier P. , Vuletic T. , Tomic S. , Heritier M. , Jerome D.
Published: July 2021

In a small range of pressure, superconductivity (SC) and Spin Density Wave (SDW) states are shown to coexist in
the Bechgaard salt (TMTSF)2PF6 and the Fabre salt (TMTTF)2BF4. In (TMTSF)2PF6, a precise investigation of the (P,T) phase
diagram has led us to demonstrate the coexistence of the two phases with a superconducting critical temperature which is
pressure independent while the critical current at zero field is strongly depressed as the pressure is decreased. In
(TMTTF)2BF4, using non-linear transport measurements, we present the signature of the presence of 1D superconducting
filaments in a small range of pressure. We also investigate the compound under a magnetic field applied along the c*-axis: the
upper critical field is more or less pressure independent and is about 2 Tesla (at zero temperature). We suggest that such a high
critical field is compatible with the penetration of the magnetic field in the insulating regions of the compound in a similar way
of Josephson vortices in layered superconductors.
Inversion of DNA charge by a positive polymer via fractionalization
of the polymer charge
Authors: Nguyen T. T. , Shklovskii B. I.
Published: July 2021

Charge inversion of a DNA double helix by an oppositely charged flexible
polyelectrolyte (PE) is widely used for gene delivery. It is considered here in terms of discrete charges
of DNA. We concentrate on the worst scenario case when in the neutral state of the DNA-PE
complex, each of the DNA charges is locally compensated by a PE charge and show that charge
inversion exists even in this case. When an additional PE molecule is adsorbed by DNA, its
charge gets fractionalized into monomer charges of defects (tails and arches) on the background
of the perfectly neutralized DNA. These charges spread all over the DNA eliminating the
self-energy of PE. Fractionalization leads to a substantial charge inversion of DNA.
The stripe-liquid phase in cuprates and nickelates
Authors: Tranquada J. M.
Published: July 2021

It is well established that doped 2D antiferromagnets such as layered nickelates and
certain cuprates can exhibit an ordered phase in which charge carriers are segregated to
periodically-spaced domain walls separating antiferromagnetic domains. An open question concerns the nature
of the state that is achieved when a stripe solid melts. Recent neutron scattering experiments on
nickelates and cuprates indicate that melting leads to a stripe-liquid state; these results will be
presented and discussed. The existence of the stripe-liquid phase in nickelates makes it plausible
to interpret the mid-infrared absorption in terms of transitions from valence to mid-gap states
associated with the stripes.
Spin and charge ordering transitions in stripes
Authors: Kruger F. , Scheidl S.
Published: July 2021

We study the interplay of topological excitations in stripe phases: charge
dislocations, charge loops, and spin vortices. In two dimensions these defects interact logarithmically
on large distances. Using a renormalization-group analysis in the Coulomb gas representation of
these defects, we calculate the phase diagram and the critical properties of the transitions.
Depending on the interaction parameters, spin and charge order can disappear at a single transition
or in a sequence of two transitions (spin-charge separation). These transitions are non-universal
with continuously varying critical exponents. We also determine the nature of the points where
three phases coexist.
Spin nematics revisited
Authors: Cvetkovic V. , Zaanen J. , Nussinov Z.
Published: July 2021

Biquadratic spin 1 Heisenberg spin systems can be constructed exhibiting spin nematic order
in higher dimensions. In terms of the original spin degrees of freedom, the spontaneous
nematic symmetry breaking generates a Z2 gauge invariance. Using a generalized
Holstein-Primakoff transformation for the underlying U(3) dynamical algebra, we calculate the spin
dynamical form factor. Although spin is not a gauge singlet, we find form factor to be finite at
finite q and $$\backslash$omega$\backslash$$, contrary to our expectations regarding the presence of a energy scale
protecting the gauge invariance. This result appears to be perturbatively stable.
Temporally-ordered CDW creep in pure and doped NbSe3
Authors: Cicak K. , O'Neill K. , Thorne R. E.
Published: July 2021

Below T=40 K, charge-density wave (CDW) transport in NbSe3 is characterized by two
well-defined driving force thresholds ET and ET*.
Between these thresholds the CDW moves
extremely slowly with creep-like temperature and driving force dependencies. At the same
time, the CDW exhibits coherent oscillations with a frequency proportional to the CDW
current and having very narrow spectral widths, suggesting that the collective motion is
temporally ordered. We have extended our initial work to doped crystals containing
isoelectronic (Ta) and nonisoelectronic (Ti) impurities, and to crystals of different
thicknesses. These experiments show that the qualitative features are extremely robust, and
that the functional form of the creep velocity versus driving force and temperature is
consistent across all samples for currents ranging over five orders of magnitude. The
temperature dependence is consistent with processes having an energy comparable to the
CDW gap, but the field and impurity dependencies are inconsistent with all predicted
functional forms for creep in CDWs and related systems, and with our earlier picture of
amplitude collapse at each impurity. We compare our results to measurements of creep-like
behavior in other CDW and SDW systems, and discuss possible mechanisms.
Modelling of phase distributions in MCrAlY coatings and their interactions with nickel based alloys
Authors: Achar D. R.G. , Munoz-Arroyo R. , Singheiser L. , Quadakkers W. J.
Published: July 2021

At high operating temperatures the oxidation resistant MCrAlY (M=Ni, Co) coatings and the substrate alloys are highly susceptible to phase changes, particularly, after long hours of exposure. With the advent of computational modelling involving metallurgical thermodynamics and diffusion parameters in recent times, it is now possible to follow these phase changes and interdiffusion processes through simulation. In the present work, phase changes in the temperature range between 950 and 1050 °C in the MCrAlY coating materials containing additions of Cobalt and Rhenium have been determined through such an approach. Further, using a diffusion simulation software interdiffusion between a commercial NiCoCrAlY coating and a Nickel-base superalloy substrate material at 1000 °C has been simulated. The simulated results have been compared with the experimental findings and they are found to be in reasonable agreement with each other. Some deviations observed are discussed in the light of limited availability of thermodynamic and kinetic data.
Estimation of a heat source by using the measured temperatures and micrographic informations; application to an electron beam welding process
Authors: Guo J. , Le Masson P. , Artioukhine E. , Loulou T. , Rogeon P. , Carron D. , Carin M. , Dumons M. , Costa J.
Published: July 2021

This paper is concerned with the estimation of a heat source applied in the electron beam welding process by using the micrographic information (hardness, optical micrograph...) and temperature measurements in solid phase. The aim is to identify the energy distribution which is applied in the liquid and vapor zones. This identification is realized at each time in a transversal plan perpendicularly to the welding axis. For this work, the goal is to analyze the feasibility of the estimation. So we don’t use noise with the theoretical measurements. At last, the iterative regularization method will be used for this two-dimensional metallurgical inverse heat transfer problem.
A new method for the numerical simulation of induction hardening processes
Authors: Pascal R. , Conraux P. , Bergheau J.-M.
Published: July 2021

Numerical simulation of induction
heating operations rests on the modelling of coupled non-linear
thermal and magnetodynamic analyses. Strong couplings come from, on
one hand, the power dissipated through Joule effect, and on the
other hand, electromagnetic properties that depend on temperature.
Usually, an indirect or staggered method is used to solve such
problems. Several magnetodynamic and thermal simulations are
therefore performed alternatively and sequentially. This paper
presents a new method solving thermo-metallurgical and
magnetodynamic problems together and based on the harmonic balance
finite element formulation (HBFEM) of the electromagnetic problem.
The temperature and the different harmonics of the Fourier series of
the unknown electromagnetic variables are now calculated in a same
finite element. An example of the numerical simulation of an
induction hardening process is presented. The results obtained with
different approaches are compared.
Computational modeling of electroslag remelting processes
Authors: K.M Kelkar  , Mok J. , Patankar S. V. , Mitchell A.
Published: July 2021

Alloys used for the production of rotating components in aeroengines and land-based turbines are subject to stringent requirements to ensure absence of melt-related defects such as inclusions and segregation. Accordingly, the production of the superalloys alloys used in these applications involves multiple remelting stages, each of which plays a distinct role in ensuring that the final ingot is defect-free. Because of the complexity of these processes, high-temperature environments, and high initial and operating costs, trial-and-error based approaches for process design are inadequate. Computational modeling provides fundamental understanding of the physical phenomena and quantitative information about the effects of process parameters. Therefore, such models are very useful for design of new processes and optimization of existing processes.
The paper describes a generalized framework for the modeling of the Electro-Slag Remelting (ESR) process. The model accounts for electromagnetic, fluid flow and heat transfer phenomena in a coupled manner for axisymmetric, steady-state conditions. A control-volume based computational method is used for the solution of the governing equations. The model incorporates a number of physically motivated computational features for efficient and accurate analysis of the transport processes. These include use of the effective viscosity approach for handling the liquid, mushy, and solid regions, implicit treatment of the interaction at the slag-metal interface, and contact heat transfer at the ingot-mold interface. Further, the computational method has been enhanced to address the AC electromagnetics in the ESR process. Thus, the model is able to predict the Joule heating within the slag, the distribution of the Lorentz force, the pool shape, and the motion in the slag and metal pools that arises due to buoyancy and Lorentz forces. The model is being validated using available experimental measurements for pool shape in full- scale ESR furnaces. Results of the model predictions for the flow, temperature, and electromagnetic fields are presented along with a comparison of the predicted and measured pool shapes.
Modelling and experimental study of the bainitic transformation, residual stresses and deformations in the quenching process of middle alloyed steel parts
Authors: Veaux M. , Denis S. , Archambault P.
Published: July 2021

Big efforts have been made these last twenty years in order to model the behaviour of steel parts in heat treatment processes [1]. Models for microstructural evolutions during continuous cooling, coupled with thermomechanical calculations do exist, but complete experimental validations of these models are still necessary. Here, we mainly present a complete experimental validation procedure from the scale of small homogeneous specimen to the scale of massive pieces with thermal gradients. Comparisons between experimental and calculated results (transformation kinetics and thermomechanical behaviour) are presented first. Then, massive cylinders quenched in air, cold oil and cold water are considered and numerical simulation results in terms of microstructure distributions, residual stresses and deformation are compared to experimental ones. The whole study concerns more specifically the bainitic transformation of a middle alloyed steel and it is shown that the effect of internal stresses on the transformation kinetics is a first order parameter in order to predict correctly microstructural gradients developed in a quenched part.
Application of numerical simulation of heat treatment in industry
Authors: Slováček M.
Published: July 2021

Heat treatment and especially quenching causes distortion and sometimes cracking of a quenched part. To eliminate these undesired by-effects the whole cycle of heat treatment is simulated by FEM, which makes possible a complete metallurgical, thermal and thermoplastic calculation. The goal of this simulation is to bring the whole cycle of heat treatment to optimum - to reach the lowest level of residual stresses possible at its end and to meet the mechanical qualities required by the customer. A lot of complete numerical simulation of heat treatment were done at the Institute of Applied Mechanics (IAM) by the SYSWELD code, mainly the heat treatment of big shafts and plates for Vitkovice Company. The Vitkovice, JSC produces ship-shafts of large dimensions (diameter 2.5 m, length 10m) and other products which are forged and consequently heat treated. Heat treatment consists of quenching (in water, air and oil), and then tempering follows.The whole simulation was divided into two parts. The aim of the first part was to find correct input data for calculation..The second part consisted of heat treatment simulation with real models.
Mechanical effects of water quenching on aluminum automotive parts
Authors: Auburtin P. , Morin N. , Pille C.
Published: July 2021

Computer modeling is nowadays necessary in order to achieve proper automotive components in short development times and low costs.
To reach the required high accuracy, process and manufacturing operations, such as heat treatments, must be included in simulations. Indeed, they generate residual stresses, which strongly influence high cycle fatigue life, as well as geometrical distortions, which need to be evaluated and corrected in order to manufacture parts within the proper dimensional tolerances.
Recent developments undertaken at PSA Peugeot-Citroën have enabled the development of a methodology to evaluate the residual stresses and distortions generated during T6-T7 heat treatment of aluminum automotive components. The calculation with Abaqus finite element software, developed on a cylinder head, follows 2 different steps: a thermal analysis and a mechanical analysis. The comparison between the simulation results and experimental measures is encouraging. Moreover, coupled with high cycle fatigue life, failures encountered during engine tests can be now explained. The methodology has also been applied on other aluminum automotive components, such as cast alloy wheels and engine cradles.
Patient-Reported Outcome Measurement Information System (PROMIS) in Orthopaedic Trauma Research
Authors: Sperring Colin P. , Danford Nicholas C. , Saltzman Bryan M. , Constant Michael , Dantzker Nicholas J. , Trofa David P.
Published: July 2021

This review describes the development, advantages and disadvantages, and applications of the Patient-Reported Outcome Measurement Information System (PROMIS) in orthopaedic trauma. PROMIS is a useful tool for quantifying outcomes in orthopedic trauma. It allows measurement of outcomes across multiple domains while minimizing administration time. PROMIS also reliably identifies clinical, social, and psychological risk factors for poor outcomes across a variety of orthopaedic injuries and disease states. However, PROMIS lacks specificity for certain anatomic regions and validation for mental health outcomes. It also is limited by ceiling effects in certain active patient populations. Orthopaedic traumatologists should be familiar with PROMIS, as its use is increasing and it is a valuable tool that can aid in clinical decision making.
A quasi-experimental evaluation of the impact of forensic property marking in decreasing burglaries
Authors: Chainey Spencer
Published: July 2021

Property marking is a popular tool used by police agencies in burglary prevention programmes. 345 property marking kits were distributed to households in a treatment area in an English city. Changes in burglary in the treatment area were compared to three control areas. Crime type displacement to vehicle crime, criminal damage and violent crime, and changes in crime while controlling for geographic displacement were examined. Burglary decreased significantly by 82% in the treatment area in comparison to control areas during the first six months of the intervention. A significant diffusion of benefit effect to vehicle crime and criminal damage was also observed. The decreases, however, were short-lived with burglary levels returning to pre-intervention levels in the treatment area after 12 months.
Dual-band metasurface for broadband asymmetric transmission with high efficiency
Authors: Han Juzheng , Chen Rushan
Published: July 2021

In this paper, a dual-band asymmetric transmission metasurface for linearly polarized wave is designed, analyzed, and verified experimentally for operation in S- and C-bands. The metasurface is established by a bi-anisotropy structure with three metallic layers separated by dielectric spacers. Symmetric rectangular split-ring resonators are adopted in the top and bottom metallic layers while modified metal strip with stepped widths is utilized in the middle. Both asymmetric transmission capability and operation bandwidth are remarkably improved. According to simulation, the design yields an asymmetric transmission parameter above 0.8 within two operation bands: 2.53–2.56 and 3.80–4.71 GHz, fractional bandwidths of 1.18% and 21.39% can be deduced, respectively. The oblique incidence property is further analyzed, which demonstrates robustness response to incidence up to 50°. Two operation bands, 2.53–2.56 and 3.87–4.78 GHz, are also validated through measurement. The corresponding bandwidths 1.18% and 21.04% show tiny discrepancy related to simulated results, which validate the reliability of the design. Comparisons with other recent published results show that this structure provides relative low profile, wider operation band with high asymmetric transmission efficiency. The proposed metasurface could be applied for electromagnetic interference suppression and polarization control for modern radar and satellite communication systems and can be scaled to operate for higher frequencies with considerable bandwidth and efficiency.
Numerical simulation research on coupling of gas generator with large aspect ratio and multi-vent
Authors: Lu Xinggan , Jiang Kun , Wang Hao
Published: July 2021

The pressure distribution of the combustion system with a large aspect ratio is uneven, and the process of gas flowing out through the vent holes arranged along the axial direction is inconsistent. Therefore, a multi-vent gas generator was designed and experimented. The experimental results show that the vent holes of each group arranged along the axial direction can be opened simultaneously. Based on the explicit dynamics method, the finite element model of the gas generator is established. The interior ballistic program is used to calculate the pressure field, and ABAQUS is used to simulate the structural dynamics. These two are coupled and solved through the subprogram interface VUAMP. The coupled calculation results show that the simulated values are in good agreement with the experimental values, which verifies the accuracy of the coupled model. The response time and opening time of the vent holes decrease with the increase in the propellant mass. The force analysis of the axial motion process is carried out. In the early stage, the frictional resistance and gas thrust rise concurrently with the improvement of gas pressure, but the influence of the former gradually diminishes compared with the latter. In the later stage, the impact of reaction force provided by rubber cushion is greater than that of gas thrust and frictional resistance. The maximum compression deformation of rubber cushion is less affected by the propellant mass, which effectively plays the role of buffering and braking.
Influence of the Madden-Julian Oscillation on multiweek prediction of Australian rainfall extremes using the ACCESS-S1 prediction system
Authors: Marshall Andrew G. , Hendon Harry H. , Hudson Debra
Published: July 2021

We assessed the ability of the Bureau of Meteorology’s ACCESS-S1 dynamical forecast system to simulate and predict high rainfall extremes for each season over Australia, especially focusing on the role of the Madden-Julian Oscillation (MJO). Using retrospective forecasts for the period 1990–2012, we show that ACCESS-S1 simulated the observed modulation of extreme weekly mean rainfall by each phase of the MJO reasonably well; however the simulated changes in probabilities tended to be weaker than those observed, especially across the far north during the austral summer season. The ability of the model to (i) simulate the observed modulation of extreme rainfall and (ii) predict the MJO to a lead time of four weeks, translated to enhanced forecast skill for predicting the occurrence of extreme weekly mean rainfall across much of Australia at times when the MJO was strong, compared to when the MJO was weak, during the austral spring and summer seasons in weeks 2 and 3. However, skill reduced across the central far north during the summer when the MJO was strong, suggesting the model is not good at depicting the MJO’s convective phases as it protrudes southward over northern Australia. During autumn and winter, there was little indication of changes in forecast skill, depending on the strength of the MJO. The results of this study will be useful for regional applications when the MJO is forecast to be strong during spring and summer, particularly where the swing in probability of extreme rainfall is large for specific phases of the MJO.
Industry environmental offset funding facilitates a large multi-species fauna translocation program
Authors: Dunlop Judy , Smith Andrew , Burbidge Allan H. , Thomas Neil , Hamilton Neil A. , Morris Keith
Published: July 2021

Worldwide deterioration in natural communities has led to an increased use of fauna translocations to improve conservation status and restore ecological function. However, few translocation programs have sufficient resources to involve multiple species and destination locations with appropriate threat management and monitoring before and after release. As part of conservation actions to mitigate impacts of the Chevron Australia Gorgon liquefied natural gas project on Barrow Island Nature Reserve, biodiversity offset funding was provided to benefit species impacted by the development. Animals were translocated from three islands to two mainland locations in Western Australia. We aimed to: (1) improve conservation status and security of several threatened species; and (2) contribute to reconstruction of pre-European fauna assemblages. Nine hundred and seventy five individuals of six mammal and two bird species were translocated. These included 421 golden bandicoots (Isoodon auratus barrowensis), 111 spectacled hare-wallabies (Lagorchestes conspicillatus conspicillatus), 105 Barrow Island boodies (Bettongia lesueur ssp. Barrow Island), 104 brushtail possums (Trichosurus vulpecula hypoleucus), 62 mala (Lagorchestes hirsutus ssp. Tanami), 88 djoongari (Pseudomys fieldi), 37 black and white fairy-wrens (Malurus leucopterus edouardi) and 47 spinifexbirds (Eremiornis carteri). Of 11 new populations, only two failed to establish; attributed to native and feral predators. Additional populations of four species of threatened mammal (one of which has now been reduced in conservation listing) and one species of threatened bird were established. To our knowledge, this is the largest translocation effort ever undertaken in Australia and is a rare example of an offset that has provided tangible threatened species benefit.
Barriers to HIV testing in hospital settings within a culturally diverse urban district of Sydney, Australia
Authors: Power Melissa , Dong Kevin , Walsh Jennifer , Lewis David A. , Richardson Daniel
Published: July 2021

Background Eleven percent of people living with HIV in Australia remain unaware of their diagnosis, and there are missed opportunities for HIV testing in priority settings in New South Wales. HIV testing remains low outside of sexual health clinics with the exception of antenatal settings where HIV testing is routine. To understand why HIV testing rates are low, we sought to identify health worker-related barriers to HIV testing. Methods: We conducted an anonymous online survey to health workers in Western Sydney Local Health District (WSLHD) in September 2019. Tick-box, Likert scale responses were analysed using Chi-square and Kruskal–Wallis statistical tests, and free text responses were analysed with thematic analysis. Results: Three percent (n = 420) of WSLHD’s estimated 14 000 health workers responded. These included 317 clinicians (171 nurses, 65 doctors, 56 allied health professionals (AHPs), 25 midwives, and 103 health workers in non-clinical roles). Health workers were from a variety of in-patient/out-patient settings. Many health workers (291/420, 69%; 95%CI = 64.9–73.7%) were unaware that HIV testing is offered in their areas; doctors (82%) and midwives (80%) were more aware than nurses (23%) and AHPs (11%) (P < 0.0001). Doctors (Likert score = 3.62; 3.45/5) and midwives (2.84; 2.76) were significantly more comfortable discussing and confidently offering HIV testing than nurses (2.42; 1.81) or AHPs (1.83; 0.91) (P < 0.0001 for both). The top five barriers to HIV testing were (1) procedural knowledge, (2) identification of at-risk patients, (3) HIV knowledge, (4) positive result management, and (5) privacy concerns. Free text responses highlighted perceived stigma, testing/result responsibilities and resource challenges as barriers to HIV testing. Conclusions: Clinicians working in priority settings and with priority populations require more education and support to increase targeted HIV testing.
Deactivation blocks proton pathways in the mitochondrial complex I
Authors: Röpke Michael , Riepl Daniel , Saura Patricia , Di Luca Andrea , Mühlbauer Max E. , Jussupow Alexander , Gamiz-Hernandez Ana P. , Kaila Ville R. I.
Published: July 2021

Significance

The electron transport chain of mitochondria is initiated by the respiratory complex I that converts chemical energy into a proton motive force to power synthesis of adenosine triphosphate. On a chemical level, complex I catalyzes elementary electron and proton transfer processes that couple across large molecular distances of >300 Å. However, under low oxygen concentrations, the respiratory chain operates in reverse mode and produces harmful reactive oxygen species. To avoid cell damage, the mitochondrial complex I transitions into a deactive state that inhibits turnover by molecular principles that remain elusive. By combining large-scale molecular simulations with cryo-electron microscopy data, we show here that complex I deactivation blocks the communication between proton pumping and redox modules by conformational and hydration changes.
Learning Chinese political formulaic phraseology from a self-built bilingual United Nations Security Council corpus
Authors: Wu Baimei , Cheung Andrew K.F. , Xing Jie
Published: July 2021

This pilot study investigates the formulaic phraseology most frequently used in highly formulaic political documents by examining a self-built bilingual parallel corpus of 43 speeches delivered in United Nations Security Council (UNSC) meetings by Chinese representatives. The study also probes corpus-based approaches to explore formulaic phraseology and demonstrates a method to retrieve Chinese formulaic phraseology from the UNSC corpus. Formulaic phraseology is often seen in political discourse. It can be defined as a sequence, continuous or discontinuous, of words or other meaning elements that are, or appear to be, prefabricated, stored and retrieved whole from memory at the time of use rather than being subject to generation or analysis by the language grammar. This study begins with a literature review of formulaic phraseology, including its features and significance in simultaneous interpreting. It then exhibits a four-step retrieval process with the Sketch Engine software program to acquire Chinese formulaic phraseology from the corpus to fill previous studies’ gap. Key functional units of the Sketch Engine, including Wordlist, N-grams, and Concordance, are used to extract formulaic phraseology from the UNSC corpus. Methodological issues involved in identifying formulaic phraseology, such as length of phraseology and quantitative criteria (frequency and dispersion thresholds), are also discussed in the study. Three types of formulaic phraseology are identified: (1) greeting representatives and other members and expressing appreciation; (2) expressing concerns about the topic of the meeting; (3) expressing China’s viewpoints about the topic of the meeting. The training of interpreters would be more effective if this categorization of formulaic phraseology is incorporated into the curriculum.
台湾对外汉语教学学科研究的发展与前景
Authors: Chao Di-kai , Moratto Riccardo
Published: July 2021

抽象的

在过去25年中，台湾对外汉语教学研究主要借鉴英语教学研究的方法，着重于开发教学策略。本文整理台湾对外汉语教学的发展后，透过分析台湾当前对外汉语教学师资和学会年会论文，来观察台湾对外汉语教学研究现状，并讨论台湾对外汉语教学学科面临的挑战。台湾对外汉语教学研究以“教学应用为大宗”，且研究仍偏向实务性强并用于课堂实践的“教学策略/技巧”之探索。相对于“教学应用”，“汉语语言本体”，“二语习得与认知”之研究显得较少，这部分反映了华语教学研究本身跨领域的性质，以及华语教学事业本身尚未获得学术独立性。
Audience constructions of fake news in Australian media representations of asylum seekers
Authors: Haw Ashleigh L.
Published: July 2021

In recent years, the term ‘fake news’ has gained considerable traction in scholarly and public discourse. While fake news
is increasingly attributed to declining audience trust, we know little about how publics are making sense of the concept. To address this, I
discuss findings arising from interviews with 24 Western Australian media consumers who offered their perspectives on Australian news
coverage of asylum seekers. Combining Critical Discourse methods with Rhetorical Analysis, findings highlight how participants evaluated
misinformation and disinformation about asylum seekers and in particular, how some adopted a discourse of ‘fake news’ to delegitimise
perspectives that oppose their own stance. Discussed alongside Egelhofer and Lecheler’s (2019)
theoretical framework of the fake news ‘label’, I argue that by understanding how audiences discussed fake news before the concept rose to
prominence in 2016, scholars can meaningfully examine discursive patterns within social constructions of fake news across numerous
contemporary and historical contexts.
The locus of parametric variation in Bantu gender and nominal derivation
Authors: Fuchs Zuzanna , van der Wal Jenneke
Published: July 2021

In this paper, we capture the crosslinguistic variation in Bantu nominal structure in a unified analysis of gender onn(Kramer 2014,2015). We demonstrate that this analysis accounts for the morphosyntactic properties of basic nouns as well as locative and diminutive derivations. Moreover, it allows us to capture intra- and inter-language morphosyntactic variation by reference to just three parameters – one strictly morphological and two structural. The presence of one or twonheads, and the size of the complement distinguish between different types of locatives (structural variation); the presence or absence of a spell-out rule of adjacentnheads differentiates “stacking” versus “non-stacking” prefixes in diminutive and augmentative derivations (morphological variation only).
Disparities in Receipt of Medications for Opioid use Disorder among Pregnant Women
Authors: Henkhaus Laura E. , Buntin Melinda B. , Henderson Sarah Clark , Lai Pikki , Patrick Stephen W.
Published: July 2021

Background: Medications for opioid use disorder (MOUD) improve outcomes for pregnant women and infants. Our primary aim was to examine disparities in maternal MOUD receipt by family sociodemographic characteristics. Methods: This retrospective cohort study included mother-infant dyads with Medicaid-covered deliveries in Tennessee from 2009 to 2016. First, we examined family sociodemographic characteristics – including race/ethnicity, rurality, mother's primary language and education level, and whether paternity was recorded in birth records – and newborn outcomes by type of maternal opioid use. Second, among pregnant women with OUD, we used logistic regression to measure disparities in receipt of MOUD by family sociodemographic characteristics including interactions between characteristics. Results: Our cohort from Medicaid-covered deliveries consisted of 314,965 mother-infant dyads, and 4.2 percent were exposed to opioids through maternal use. Among dyads with maternal OUD, MOUD receipt was associated with lower rates of preterm and very preterm birth. Logistic regression adjusted for family sociodemographic characteristics showed that pregnant women with OUD in rural versus urban areas (aOR: 0.66; 95% CI: 0.60–0.72) and who were aged ≥35 years versus ≤25 years (aOR: 0.75; 95% CI: 0.64–0.89) were less likely to have received MOUD. Families in which the mother's primary language was English (aOR: 2.47; 95% CI: 1.24–4.91) and paternity was recorded on the birth certificate (aOR: 1.30; 95% CI: 1.19–1.42) were more likely to have received MOUD. Regardless of high school degree attainment, non-Hispanic Black versus non-Hispanic White race was associated with lower likelihood of MOUD receipt. Hispanic race was associated with lower likelihood of MOUD receipt among women without a high school degree. Conclusions: Among a large cohort of pregnant women, we found disparities in receipt of MOUD among non-Hispanic Black, Hispanic, and rural pregnant women. As policymakers consider strategies to improve access to MOUD, they should consider targeted approaches to address these disparities.