bluuebunny/crossref_metadata_2025 huggingface dataset:
Harnessing an emissive guanine surrogate to design small-molecule fluorescent chemosensors of O6-methylguanine-DNA-methyltransferase (MGMT)
Authors: Fillion Alexandra , Franco Pinto Jaime , Granzhan Anton
Published: February 2022

Activity of O6-methylguanine-DNA-methyltransferase (MGMT) can be monitored in real time using chemosensors that generate an emissive guanine analogue thienoguanine (thGN).
Effects of Positive and Negative Emotions on Picture Naming for People With Mild-to-Moderate Aphasia: A Preliminary Investigation
Authors: Harmon Tyson G. , Nielsen Courtney , Loveridge Corinne , Williams Camille
Published: February 2022

Purpose:

The purpose of the study is to investigate how emotional arousal and valence affect confrontational naming accuracy and response time (RT) in people with mild-to-moderate aphasia compared with adults without aphasia. We hypothesized that negative and positive emotions would facilitate naming for people with aphasia (PWA) but lead to slower responses for adults with no aphasia.

Method:

Eight participants with mild-to-moderate aphasia, 15 older adults (OAs), and 17 young adults (YAs) completed a confrontational naming task across three conditions (positive, negative, and neutral) in an ABA (where A = neutral and B = negative) case series design. Immediately following each naming condition, participants self-reported their perceived arousal and pleasure. Accuracy and RT were measured and compared.

Results:

As expected, PWA performed significantly less accurately and with longer RTs than both YA and OA groups across all conditions. However, opposite our hypothesis for the aphasia group, the negative condition resulted in decreased accuracy for the aphasia and the OA group and increased RT across all groups. No statistically significant differences were found between the positive and any other condition. Participants with aphasia who demonstrated an effect in the negative condition were observed to produce a larger proportion of semantically related errors than any other error types.

Conclusions:

Findings suggest that strong negative emotions can interfere with semantic–lexical processing by diverting attentional resources to emotion regulation. Both clinicians and researchers should be aware of the potential influence of negative stimuli and negative emotional states on language performance for PWA, and these effects should be disentangled in future research. Further research should also be conducted with a larger number of participants with aphasia across a broader range of severity to replicate and extend findings.

Supplemental Material:

https://doi.org/10.23641/asha.19119356
Analysis of multiscale structures at the quasi-perpendicular Venus bow shock
Authors: Dimmock A. P. , Khotyaintsev Yu. V. , Lalti A. , Yordanova E. , Edberg N. J. T. , Steinvall K. , Graham D. B. , Hadid L. Z. , Allen R. C. , Vaivads A. , Maksimovic M. , Bale S. D. , Chust T. , Krasnoselskikh V. , Kretzschmar M. , Lorfèvre E. , Plettemeier D. , Souček J. , Steller M. , Štverák Š. , Trávníček P. , Vecchio A. , Horbury T. S. , O’Brien H. , Evans V. , Angelini V.
Published: February 2022

Context.Solar Orbiter is a European Space Agency mission with a suite of in situ and remote sensing instruments to investigate the physical processes across the inner heliosphere. During the mission, the spacecraft is expected to perform multiple Venus gravity assist maneuvers while providing measurements of the Venusian plasma environment. The first of these occurred on 27 December 2020, in which the spacecraft measured the regions such as the distant and near Venus magnetotail, magnetosheath, and bow shock.

Aims.This study aims to investigate the outbound Venus bow shock crossing measured by Solar Orbiter during the first flyby. We study the complex features of the bow shock traversal in which multiple large amplitude magnetic field and density structures were observed as well as higher frequency waves. Our aim is to understand the physical mechanisms responsible for these high amplitude structures, characterize the higher frequency waves, determine the source of the waves, and put these results into context with terrestrial bow shock observations.

Methods.High cadence magnetic field, electric field, and electron density measurements were employed to characterize the properties of the large amplitude structures and identify the relevant physical process. Minimum variance analysis, theoretical shock descriptions, coherency analysis, and singular value decomposition were used to study the properties of the higher frequency waves to compare and identify the wave mode.

Results.The non-planar features of the bow shock are consistent with shock rippling and/or large amplitude whistler waves. Higher frequency waves are identified as whistler-mode waves, but their properties across the shock imply they may be generated by electron beams and temperature anisotropies.

Conclusions.The Venus bow shock at a moderately high Mach number (∼5) in the quasi-perpendicular regime exhibits complex features similar to the Earth’s bow shock at comparable Mach numbers. The study highlights the need to be able to distinguish between large amplitude waves and spatial structures such as shock rippling. The simultaneous high frequency observations also demonstrate the complex nature of energy dissipation at the shock and the important question of understanding cross-scale coupling in these complex regions. These observations will be important to interpreting future planetary missions and additional gravity assist maneuvers.
Radio emission in a nearby, ultra-cool dwarf binary: A multifrequency study
Authors: Climent J. B. , Guirado J. C. , Zapatero Osorio M. R. , Zakhozhay O. V. , Pérez-Torres M. , Azulay R. , Gauza B. , Rebolo R. , Béjar V. J. S. , Martín-Pintado J. , Lefèvre C.
Published: February 2022

Context.The substellar triple system VHS J125601.92−125723.9 (hereafter VHS 1256−1257) is composed of an equal-mass M7.5 brown dwarf binary and an L7 low-mass substellar object. In Guirado et al. (2018, A&A, 610, A23) we published the detection of radio emission at 8.4 GHz coming from the central binary and making it an excellent target for further observations.

Aims.We aim to identify the origin of the radio emission occurring in the central binary of VHS 1256−1257 while discussing the expected mechanisms involved in the radio emission of ultra-cool dwarfs.

Methods.We observed this system with theKarl G. JanskyVery Large Array, the European very-long-baseline interferometry (VLBI) Network, the enhanced Multi-Element Remotely Linked Interferometer Network, the NOrthern Extended Millimeter Array, and the Atacama Large Millimetre Array at frequencies ranging from 5 GHz up to 345 GHz in several epochs during 2017, 2018, and 2019.

Results.We found radio emission at 6 GHz and 33 GHz coincident with the expected position of the central binary of VHS 1256−1257. The StokesIdensity fluxes detected were 73 ± 4 μJy and 83 ± 13 μJy, respectively, with no detectable circular polarisation or pulses. No emission is detected at higher frequencies (230 GHz and 345 GHz), nor at 5 GHz with VLBI arrays. The emission appears to be stable over almost three years at 6 GHz. To explain the constraints obtained both from the detections and non-detections, we considered multiple scenarios including thermal and nonthermal emission, and different contributions from each component of the binary.

Conclusions.Our results can be well explained by nonthermal gyrosynchrotron emission originating at radiation belts with a low plasma density (ne = 300−700 cm−3), a moderate magnetic field strength (B ≈ 140 G), and an energy distribution of electrons following a power-law (dN/dE ∝ E−δ) withδfixed at 1.36. These radiation belts would need to be present in both components and also be viewed equatorially.
TOI-1759 b: A transiting sub-Neptune around a low mass star characterized with SPIRou and TESS
Authors: Martioli E. , Hébrard G. , Fouqué P. , Artigau É. , Donati J.-F. , Cadieux C. , Bellotti S. , Lecavelier des Etangs A. , Doyon R. , do Nascimento J.-D. , Arnold L. , Carmona A. , Cook N. J. , Cortes-Zuleta P. , de Almeida L. , Delfosse X. , Folsom C. P. , König P.-C. , Moutou C. , Ould-Elhkim M. , Petit P. , Stassun K. G. , Vidotto A. A. , Vandal T. , Benneke B. , Boisse I. , Bonfils X. , Boyd P. , Brasseur C. , Charbonneau D. , Cloutier R. , Collins K. , Cristofari P. , Crossfield I. , Díaz R. F. , Fausnaugh M. , Figueira P. , Forveille T. , Furlan E. , Girardin E. , Gnilka C. L. , Gomes da Silva J. , Gu P.-G. , Guerra P. , Howell S. B. , Hussain G. A. J. , Jenkins J. M. , Kiefer F. , Latham D. W. , Matson R. A. , Matthews E. C. , Morin J. , Naves R. , Ricker G. , Seager S. , Takami M. , Twicken J. D. , Vanderburg A. , Vanderspek R. , Winn J.
Published: February 2022

We report the detection and characterization of the transiting sub-Neptune TOI-1759 b, using photometric time series from the Transiting Exoplanet Survey Satellite (TESS) and near-infrared spectropolarimetric data from the Spectro-Polarimètre Infra Rouge (SPIRou) on the Canada-France-Hawaii Telescope. TOI-1759 b orbits a moderately active M0V star with an orbital period of 18.849975 ± 0.000006 days, and we measured a planetary radius and mass of 3.06 ± 0.22 R⊕ and 6.8 ± 2.0 M⊕. Radial velocities were extracted from the SPIRou spectra using both the cross-correlation function and the line-by-line methods, optimizing the velocity measurements in the near-infrared domain. We analyzed the broadband spectral energy distribution of the star and the high-resolution SPIRou spectra to constrain the stellar parameters and thus improve the accuracy of the derived planet parameters. A least squares deconvolution analysis of the SPIRou Stokes V polarized spectra detects Zeeman signatures in TOI-1759. We modeled the rotational modulation of the magnetic stellar activity using a Gaussian process regression with a quasi-periodic covariance function and find a rotation period of 35.65−0.15+0.17 days. We reconstructed the large-scale surface magnetic field of the star using Zeeman-Doppler imaging, which gives a predominantly poloidal field with a mean strength of 18 ± 4 G. Finally, we performed a joint Bayesian Markov chain Monte Carlo analysis of the TESS photometry and SPIRou radial velocities to optimally constrain the system parameters. At 0.1176 ± 0.0013 au from the star, the planet receives 6.4 times the bolometric flux incident on Earth, and its equilibrium temperature is estimated at 433 ± 14 K. TOI-1759 b is a likely gas-dominated sub-Neptune with an expected high rate of photoevaporation. Therefore, it is an interesting target to search for neutral hydrogen escape, which may provide important constraints on the planetary formation mechanisms responsible for the observed sub-Neptune radius desert.
Strong Lyman continuum emitting galaxies show intense C IV λ1550 emission
Authors: Schaerer D. , Izotov Y. I. , Worseck G. , Berg D. , Chisholm J. , Jaskot A. , Nakajima K. , Ravindranath S. , Thuan T. X. , Verhamme A.
Published: February 2022

Using the Space Telescope Imaging Spectrograph, we have obtained ultraviolet spectra from ∼1200 to 2000 Å of known Lyman continuum (LyC) emitting galaxies at low redshift (z ∼ 0.3 − 0.4) with varying absolute LyC escape fractions (fesc ∼ 0.01 − 0.72). Our observations include in particular the galaxy J1243+4646, which has the highest known LyC escape fraction at low redshift. While all galaxies are known Lyman alpha emitters, we consistently detect an inventory of additional emission lines, including C IV λ1550, He II λ1640, O III] λ1666, and C III] λ1909, whose origin is presumably essentially nebular. C IV λ1550 emission is detected above 4σ in six out of eight galaxies, with equivalent widths of EW(C IV) = 12 − 15 Å for two galaxies, which exceeds the previously reported maximum emission in low-z star-forming galaxies. We detect C IV λ1550 emission in all LyC emitters with escape fractions fesc >  0.1 and find a tentative increase in the flux ratio C IV λ1550/C III] λ1909 with fesc. Based on the data, we propose a new criterion to select and classify strong leakers (galaxies with fesc >  0.1): C IV λ1550/C III] λ1909 ≳ 0.75. Finally, we also find He II λ1640 emission in all the strong leakers with equivalent widths from 3 to 8 Å rest frame. These are among the highest values observed in star-forming galaxies and are primarily due to a high rate of ionizing photon production. The nebular He II λ1640 emission of the strong LyC emitters does not require harder ionizing spectra at > 54 eV compared to those of typical star-forming galaxies at similarly low metallicity.
Simulation quantique avec des atomes froids. Comment manipuler et sonder des systèmes quantiques à l’échelle de l’atome individuel
Authors: Yefsah Tarik , Sayrin Clément
Published: February 2022

Les systèmes physiques à grand nombre de particules, d’une importance capitale en physique, sont incroyablement complexes. Leur comportement, en effet, « ne doit pas être compris à travers une simple extrapolation des propriétés de quelques particules. Au contraire, à chaque niveau de complexité, des propriétés entièrement nouvelles émergent (…) » (P.W. Anderson [1]).

L’avènement des technologies quantiques, et tout particulièrement de la simulation quantique, permet aujourd’hui d’aborder d’une façon nouvelle et prometteuse la physique de ces systèmes à N corps en interaction. Nous présentons ici l’apport des dispositifs à atomes froids, à travers deux exemples d’expériences aujourd’hui en construction au Laboratoire Kastler Brossel.
Les nouvelles diodes électroluminescentes pour l’émission UV
Authors: Brault Julien , Damilano Benjamin , Duboz Jean-Yves , Gil Bernard
Published: February 2022

Les propriétés germicides des rayonnements ultraviolets (UV) suscitent un intérêt de plus en plus important dans les domaines d’applications stratégiques que sont l’environnement et la santé. Les diodes électroluminescentes (LEDs) semi-conductrices à base de nitrure d’aluminium et de gallium représentent les nouvelles sources d’émission UV qui pourront répondre à cette demande. Leurs performances, bien qu’encore modestes, progressent chaque jour et nous vivons le point de bascule entre le laboratoire et le domaine grand public. Pour définitivement parvenir à s’imposer, elles doivent associer efficacité, forte capacité de développement, ainsi que souplesse et facilité d’utilisation, performances qu’aucune source UV n’a encore atteint jusqu’à présent.
Des cellules solaires dont la transparence et la production d’énergie s’adaptent aux conditions d’ensoleillement
Authors: Demadrille Renaud
Published: February 2022

En laboratoire, les cellules solaires à colorant démontrent aujourd’hui des efficacités supérieures à 14% et peuvent être semi-transparentes, colorées et très efficaces sous de faibles irradiations. Elles ont récemment amorcé leur développement industriel avec des exemples d’intégration dans des façades de bâtiments.

Dans cet article, nous rappellerons le principe de fonctionnement de ces cellules, puis nous reviendrons sur nos travaux visant à développer des colorants applicables en cellules semitransparentes. Enfin, nous présenterons une nouvelle classe de photosensibilisateurs qui permettent d’obtenir des cellules solaires capables de changer de couleur et d’auto-ajuster simultanément leur transparence et leur production d’énergie en fonction des conditions d’ensoleillement.
Use of Rapid Molecular Polymerase Chain Reaction in Early Detection of Bacteremia in Neonates Prior to Blood Culture Positivity: A Pilot Study
Authors: Massa-Buck Beri , Mendoza Salome , Keiser John , Mohamed Mohamed A.
Published: February 2022

Objective There has been national strive to decrease the time needed to identify microorganisms in blood culture samples to reduce antibiotic use. This study evaluated rapid molecular polymerase chain reaction (PCR) use in identifying microorganisms in negative culture bottles from neonates with suspected bacterial blood stream infection at 20 to 24 hours of incubation.

Study Design All blood specimens from neonates with suspected blood stream infection were included. Specimens were incubated using a standard blood culturing instrument that would flag positive if bacterial growth was detected. If the specimen was flagged positive at <20 hours, it was tested by PCR and plated for identification as per standard protocol. In our design, if specimen was not flagged at 20 hours of incubation, the bottle was sterilely accessed and a sample was obtained for PCR testing. The bottle would be returned for incubation for 120 hours or until flagged positive.

Results A total of 192 blood specimens were included. Four specimens flagged positive at <20 hours and were all found to be positive by PCR. All other samples did not flag positive by 20 hours of incubation and were tested by PCR between 20 and 24 hours. One sample tested positive via PCR at 21.6 hours then flagged positive on the culturing instrument at 23.5 hours. All other specimens were negative by PCR and remained culture negative at 120 hours. The positive and negative predictive value of PCR verified by blood culture were both equal to 1.0.

Conclusion Using rapid molecular PCR on blood culture specimens at 20 to 24 hours of incubation provides 100% true negative results possibly allowing providers to discontinue antibiotics at 24 hours.

Key Points
Chemically realistic coarse-grained models for polyelectrolyte solutions
Authors: Kaur Supreet , Yethiraj Arun
Published: February 2022

Polyelectrolyte solutions are of considerable scientific and practical importance. One of the most widely studied polymer is polystyrene sulfonate (PSS), which has a hydrophobic backbone with pendant charged groups. A polycation with similar chemical structure is poly(vinyl benzyltri methyl) ammonium (PVBTMA). In this work, we develop coarse-grained (CG) models for PSS and PVBTMA with explicit CG water and with sodium and chloride counterions, respectively. We benchmark the CG models via a comparison with atomistic simulations for single chains. We find that the choice of the topology and the partial charge distribution of the CG model, both play a crucial role in the ability of the CG model to reproduce results from atomistic simulations. There are dramatic consequences, e.g., collapse of polyions, with injudicious choices of the local charge distribution. The polyanions and polycations exhibit a similar conformational and dynamical behavior, suggesting that the sign of the polyion charge does not play a significant role.
Compact topological waveguide for acoustic enhanced directional radiation
Authors: Tong Shuaishuai , Ren Chunyu , Tao Jun
Published: February 2022

Enhanced directional radiation is important for various applications such as lasers and antennas. However, almost all existing enhanced directional emitters rely on the use of materials or structures that provide multiple reflections, which are often bulky, lossy, and difficult to fabricate. Here, we theoretically propose and experimentally demonstrate acoustic enhanced directional radiation with topological interface states in a specially designed acoustic waveguide with subwavelength width and no additional structure for multiple reflections. This waveguide is an acoustic analog of the double Su–Schrieffer–Heeger chain, in which a topological bandgap can be created by opening degenerate points away from the boundary of the Brillouin zone. Topological interface states between two topologically different waveguides were experimentally observed. A leaky-wave design is proposed for acoustic enhanced directional radiation. This leaky-wave waveguide can improve the radiation resistance and efficiency of a point source, and the radiation direction is locked by the momentum of the degenerate points. Acoustic enhanced directional radiation with more than ten times energy enhancement is observed in the experiment. The proposed strategy shows potential in the subwavelength wave manipulation and can be applied to acoustic communication, nondestructive evaluation, and biomedical imaging.
Exploring cesium–tellurium phase space via high-throughput calculations beyond semi-local density-functional theory
Authors: Saßnick Holger-Dietrich , Cocchi Caterina
Published: February 2022

Boosted by the relentless increase in available computational resources, high-throughput calculations based on first-principles methods have become a powerful tool to screen a huge range of materials. The backbone of these studies is well-structured and reproducible workflows efficiently returning the desired properties given chemical compositions and atomic arrangements as sole input. Herein, we present a new workflow designed to compute the stability and the electronic properties of crystalline materials from density-functional theory using the strongly constrained and appropriately normed approximation (SCAN) for the exchange–correlation potential. We show the performance of the developed tool exploring the binary Cs–Te phase space that hosts cesium telluride, a semiconducting material widely used as a photocathode in particle accelerators. Starting from a pool of structures retrieved from open computational material databases, we analyze formation energies as a function of the relative Cs content and for a few selected crystals, we investigate the band structures and density of states unraveling interconnections among the structure, stoichiometry, stability, and electronic properties. Our study contributes to the ongoing research on alkali-based photocathodes and demonstrates that high-throughput calculations based on state-of-the-art first-principles methods can complement experiments in the search for optimal materials for next-generation electron sources.
Enregistering “gender ideology”
Authors: Borba Rodrigo
Published: February 2022

Mobilizations against gender equality and sexual diversity have gained political traction globally despite their hyperbolic modes of action and conspiracist rhetoric. These anti-gender campaigns rally around “gender ideology,” a trope used to anathemize feminist and LGBTQIA+ activism/scholarship. This paper argues that anti-genderism is a register – a conventionalized aggregate of expressive forms and enactable person-types – of which “gender ideology” is the most famous shibboleth. The paper shows how inchoate collections of words, modes of action, and images of people (i.e. signs) have been enregistered into the cohesive but heterogeneous whole of anti-genderism through semiotic processes of clasping, relaying, and grafting (Gal 2018;2019). The paper offers a sociolinguistic analysis of anti-genderism to understand the challenges it poses to the enfranchisement of women, queer, trans, and nonbinary people.
Entanglement entropy of disjoint spacetime intervals in causal set theory
Authors: Duffy Callum F , Jones Joshua Y L , Yazdi Yasaman K
Published: February 2022

A more complete understanding of entanglement entropy in a covariant manner could inform the search for quantum gravity. We build on work in this direction by extending previous results to disjoint regions in 1 + 1D. We investigate the entanglement entropy of a scalar field in disjoint intervals within the causal set framework, using the spacetime commutator and correlator, i
Δ and W (or the Pauli–Jordan and Wightman functions). A new truncation scheme for disjoint causal diamonds is presented, which follows from the single diamond truncation scheme. We investigate setups including two and three disjoint causal diamonds, as well as a single causal diamond that shares a boundary with a larger global causal diamond. In all the cases that we study, our results agree with the expected area laws. In addition, we study the mutual information in the two disjoint diamond setup. The ease of our calculations indicate our methods to be a useful tool for numerically studying such systems. We end with a discussion of some of the strengths and future applications of the spacetime formulation we use in our entanglement entropy computations, both in causal set theory and in the continuum.
Measurement techniques for aeroacoustics: from aerodynamic comparisons to aeroacoustic assimilations
Authors: Ragni Daniele , Avallone Francesco , Casalino Damiano
Published: February 2022

Sustainability has encouraged studies focusing on lowering the aeroacoustic impact of new aerodynamically optimized mechanical systems for several applications in wind-energy, aviation, automotive and urban air-mobility. The deployment of effective noise-reduction strategies starts with a deep understanding of the underlying mechanisms of noise generation. To elucidate the physics behind the onset of aerodynamic sources of sound, experimental techniques used for aerodynamic purposes have been combined with acoustic measurements. In the last decades, new experimental post-processing techniques have additionally been developed, by leveraging aeroacoustic analogies in a new multi-disciplinary framework. New approaches have been proposed with the intent of translating near-field velocity and pressure information into sound. The current review describes how such breakthroughs have been achieved, briefly starting from a historical overview, to quickly bridge to the measurement techniques and the facilities employed by the scientific community. Being the measurement principles already reported in the literature, this review only focuses on the most relevant studies trying to relate the near-field information to the perceived sound in the far-field. Aspects related to the uncertainty of the measurement techniques will be thus very briefly discussed, together with their relation to the background noise of the testing facilities, including acoustic reflections/refractions, and issues related to the instrumentation.
Optimization-based self-alignment method for stationary SINS with geographical latitude uncertainty
Authors: Li Jingchun , Duan Haibin , Yuan Guangsong , Zhang Ya
Published: February 2022

To solve the self-alignment problem of strapdown inertial navigation system (SINS) with geographical latitude uncertainty, an optimization-based self-alignment (OSA) method and its improvement for stationary SINS without using the latitude information are proposed. We use only the accelerometer and gyroscope measurements, without the aid of the external latitude information, to determine the Earth rate in the navigation frame. Then we formulate the SINS self-alignment process as a Wahba problem to overcome the disturbances of random noise, and use the estimated Earth rate vector and multiple measurements from the accelerometer and gyroscope to formulate the nonlinear objective function. Moreover, the alignment errors of the OSA method are also presented, based on which we propose a two-position OSA to estimate and compensate the horizontal accelerometer biases to further improve the alignment accuracy. The results of simulation and experiments demonstrate that the proposed OSA method and its improvement perform robust to the noise disturbances and achieve better alignment accuracy than conventional self-alignment methods.
Characterisation and optimisation of targets for plasma wakefield acceleration at SPARC_LAB
Authors: Costa G , Anania M P , Arjmand S , Biagioni A , Del Franco M , Del Giorno M , Galletti M , Ferrario M , Pellegrini D , Pompili R , Romeo S , Rossi A R , Zigler A , Cianchi A
Published: February 2022

One of the most important features of plasma-based accelerators is their compactness because plasma modules can have dimensions of the order of mm

cm

−
1

, providing very high-accelerating fields up to hundreds of GV

m

−
1

. The main challenge regarding this type of acceleration lies in controlling and characterising the plasma itself, which then determines its synchronisation with the particle beam to be accelerated in an external injection stage in the laser wakefield acceleration (LWFA) scheme. This issue has a major influence on the quality of the accelerated bunches. In this work, a complete characterisation and optimisation of plasma targets available at the SPARC_LAB laboratories is presented. Two plasma-based devices are considered: supersonic nozzles for experiments adopting the self-injection scheme of laser wakefield acceleration and plasma capillary discharge for both particle and laser-driven experiments. In the second case, a wide range of plasma channels, gas injection geometries and discharge voltages were extensively investigated as well as studies of the plasma plumes exiting the channels, to control the plasma density ramps. Plasma density measurements were carried out for all the different designed plasma channels using interferometric methods in the case of gas jets, spectroscopic methods in the case of capillaries.
A novel 3300 V trench IGBT with P-N-doped polysilicon split gate for low EMI noise
Authors: Wang Tongyang , Li Zehong , Zhao Yishang , Li Luping , Yang Yang , Xia Ziming , Ren Min , Li Wei , Zhang Jinping
Published: February 2022

A novel 3300 V trench insulated gate bipolar transistor (IGBT) with p-n-doped polysilicon split gate (PNSG-IGBT) is proposed for low electromagnetic interference noise. The reverse-biased polysilicon PN junction is laterally depleted and charged by displacement current during the turn-off transient, which raises electrostatic potential in n-region of the polysilicon PN junction (V
N) and electrostatic potential under the gate oxide (V
ACC) simultaneously. By technology computer aided design simulation, during the turn-on transient, the maximum dV
ACC
/dt is 57.1% lower than that of the split gate (SG)-IGBT with the same R
G and the excess V
GE overshoot caused by reverse displacement current is effectively suppressed. Moreover, for the same E
ON, the maximum reverse recovery dV
KA
/dt of the freewheeling diode can be reduced by 77.3% and 30.7% compared with that of the floating P region-IGBT and the SG-IGBT respectively, which is of great merit in suppressing dV/dt noise. Consequently, the PNSG-IGBT shows less common-mode noise at high frequency, especially in the range of 20–40 MHz.
Statistics of coarse-grained cosmological fields in stochastic inflation
Authors: Tada Yuichiro , Vennin Vincent
Published: February 2022

We present a generic framework to compute the one-point
statistics of cosmological perturbations, when coarse-grained at an
arbitrary scale R, in the presence of quantum diffusion. Making
use of the stochastic-δ N formalism, we show how it can be
related to the statistics of the amount of expansion realised until
the scale R crosses out the Hubble radius. This leads us to
explicit formulae for the probability density function (PDF) of the
curvature perturbation, the comoving density contrast, and the
compaction function. We then apply our formalism to the calculation
of the mass distribution of primordial black holes produced in a
single-field model containing a “quantum well” (i.e. an exactly
flat region in the potential). We confirm that the PDFs feature
heavy, exponential tails, with an additional cubic suppression in
the case of the curvature perturbation. The large-mass end of the
mass distribution is shown to be mostly driven by
stochastic-contamination effects, which produce black holes more
massive than those naively expected. This work bridges the final gap
between the stochastic-inflation formalism and the calculation of
the mass distribution of astrophysical objects such as primordial
black holes, and opens up various prospects that we finally discuss.
Beyond-mean-field dynamical correlations for nuclear mass table in deformed relativistic Hartree-Bogoliubov theory in continuum *
Authors: Sun Wei , Zhang Kai-Yuan , Pan Cong , Fan Xiao-Hua , Zhang Shuang-Quan , Li Zhi-Pan
Published: February 2022

We extend the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) to go beyond-mean-field framework by performing a two-dimensional collective Hamiltonian. The influences of dynamical correlations on the ground-state properties are examined in different mass regions, picking Se, Nd, and Th isotopic chains as representatives. It is found that the dynamical correlation energies (DCEs) and the rotational correction energies

in the cranking approximation have an almost equivalent effect on the description of binding energies for most deformed nuclei, and the DCEs can provide a significant improvement for the (near) spherical nuclei close to the neutron shells and thus reduce the rms deviations of

by

17%. Furthermore, it is found that the DCEs are quite sensitive to the pairing correlations; taking

Nd as an example, a 10% enhancement of pairing strength can raise the DCE by

37%.
Time evolution of a mean-field generalized contact process
Authors: Chariker Logan , Lebowitz Joel L
Published: February 2022

We investigate the macroscopic time evolution and stationary states of a mean field discrete voltage neuron model, or equivalently, a generalized contact process in

R

d

. The model is described by a coupled set of nonlinear integral-differential equations. It was inspired by a model of neurons with discrete voltages evolving by a stochastic integrate and fire mechanism. We obtain a complete solution in the spatially uniform case and partial solutions in the general case. The system has one or more fixed points and also traveling wave solutions.
Analysis of Impact of Distributed Photovoltaic on Main Transformer Gap Protection
Authors: Tian G , Yan P , Hu X K , Luo P , Su C , Zhang Q
Published: February 2022

Distributed photovoltaic is one of the important energy supplies in new-type power system. Notably, when the main transformer is operated in non-directly grounded mode and distributed photovoltaic is connected to the low-voltage side, faults such as single-phase grounding short-circuit may cause overvoltage problems at the neutral point of the transformer, thereby posing a threat to the insulation at the neutral point. For the main transformer neutral point voltage offset and gap protection problems, this paper first analyzes the fault characteristics of the network, the operation of the line protection and the neutral point voltage offset after the fault occurs. Furthermore, combined with the distributed photovoltaic output characteristics after the near-system protection action, this paper analyzes that the distributed photovoltaic access after the line protection action may cause the neutral point over-voltage offset to deteriorate further. Moreover, under different matching degrees of distributed capacity and local load, the degree of neutral point voltage deviation when a single-phase fault occurs in a substation with distributed photovoltaic is derived. On this basis, the criterion of gap breakdown of the main transformer and relevant suggestions for installing gap protection are given. Finally, based on the simulation analysis of the single-phase ground fault of the grid-connected line, the boundary of neutral breakdown at different fault moments are obtained, thereby effectively guiding distributed photovoltaic to access new-type power system friendly.
Effects of Building Physics Form on Energy Consumption for Buildings
Authors: Yang Yuting , Wang Peng
Published: February 2022

The building sector plays an important role in urban energy conservation and CO2 emissions reduction. Therefore, it is necessary to fundamentally explore the influencing factors and mechanisms of building energy consumption. This study aims to explore the impact of building physical form on energy consumption for buildings. Firstly, this study uses different types of buildings as research objects. And method of combining EnergyPlus and GIS is used to calculate building energy consumption. Then adopting regression analysis to evaluate the impact of six building form indicators on building energy use. The results show that building coverage ratio (BCR) has a positive relationship with point-type building energy consumption. And among mix-type buildings, sky view factor (SVF) has a positive impact on energy consumption, and building coverage ratio (BCR) has a negative impact on it. As for slab-type buildings, total wall surface area (WSA) has a positive effect on energy consumption, and building floor (BF) has a negative effect on energy consumption. However, the indicators are not enough to explain the building energy consumption, and further exploration is needed.
Research on Market Mechanism of Thermal Power Flexible Transformation to Promote Clean Energy Consumption
Authors: Shi Yu , Jiang Minglei , Gao Xuefeng , Zhang Yuanmei , Li Hao
Published: February 2022

By continuously developing a new power system aiming at “double carbon”, the peak shaving pressure of the power system continues to rise and the existing peak shaving ability is slightly weakened. But the historic energy structure in Northeast China has more features of thermal power generation. Therefore, it is urgent to improve the demand for deep peak shaving by a flexible combination of thermal power plants to realize renewable energy consumption. In view of this, this paper analyzes the current power market mechanism in Northeast China, constructs a new energy consumption model for flexible transformation of thermal power, and makes a simulation analysis in the area with wind fire ratio of 1:4. Finally, through flexible conversion of thermal power unit, wind power consumption can be better realized and the problem of wind abandonment can be solved. The research results can provide reference for formulating relevant policies and production models.
Experimental Investigation of Plume Diffusion Behavior of LNG Accident Release Underwater
Authors: Zhang Y X , Hu J , Zhu J L , Li Y X
Published: February 2022

To deal with the significantly serious problem of environmental pollution, the use of clean energy is vigorously promoted by governments and corporations in all countries. Therefore, the offshore transportation and trade of LNG has become the main way of energy supplication in cross regional. The potential risk of LNG release from ships or offshore pipelines may cause disastrous consequences, which requires a better consideration and evaluation of the consequences of LNG accidental release. The main purpose of this paper is to understand the special physical phenomena of LNG underwater leakage and the dynamic behavior of rising plume. A small-scale indoor underwater leakage experimental platform was designed and built in a wind tunnel. The plume rising behavior of underwater release of the cryogenic liquid were recorded by a high-speed camera. Through the image processing techniques, the physical model of cryogenic liquid heat transfer underwater was established and verified. In addition, the effects of different sizes and pattern of the orifices and release pressures on plume radius were evaluated. An empirical relationship for predicting the plume diffusion radius under different pool sizes was established based on the method of dimensionless analysis.
Model Extraction Attack and Defense on Deep Generative Models
Authors: Liu Shengyi
Published: February 2022

The security issues of machine learning have aroused much attention and model extraction attack is one of them. The definition of model extraction attack is that an adversary can collect data through query access to a victim model and train a substitute model with it in order to steal the functionality of the target model. At present, most of the related work has focused on the research of model extraction attack against discriminative models while this paper pays attention to deep generative models. First, considering the difference of an adversary` goals, the attacks are taxonomized into two different types: accuracy extraction attack and fidelity extraction attack and the effect is evaluated by 1-NN accuracy. Attacks among three main types of deep generative models and the influence of the number of queries are also researched. Finally, this paper studies different defensive techniques to safeguard the models according to their architectures.
Convolutional neural networks for shower energy prediction in liquid argon time projection chambers
Authors: Carloni K. , Kamp N.W. , Schneider A. , Conrad J.M.
Published: February 2022

When electrons with energies of O(100) MeV pass through a
liquid argon time projection chamber (LArTPC), they deposit energy
in the form of electromagnetic showers. Methods to reconstruct the
energy of these showers in LArTPCs often rely on the combination of
a clustering algorithm and a linear calibration between the shower
energy and charge contained in the cluster. This reconstruction
process could be improved through the use of a convolutional neural
network (CNN). Here we discuss the performance of various CNN-based
models on simulated LArTPC images, and then compare the best
performing models to a typical linear calibration algorithm. We
show that the CNN method is able to address inefficiencies caused by
unresponsive wires in LArTPCs and reconstruct a larger fraction of
imperfect events to within 5 % accuracy compared with the linear
algorithm.
Beam dynamics simulation study for longitudinal bunch length measurement of RF modulated thermionic electron gun at VECC, Kolkata
Authors: Naser M.Z.A. , Dechoudhury S. , Dutta D.P. , Hazra D. , Naik V. , Bandyopadhyay A.
Published: February 2022

A superconducting electron linac (e-linac) photo-fission
driver is under construction at VECC for the upcoming rare isotope
beam facility called ANURIB. Electron gun and straight low energy
beam transport (LEBT) line has been installed and is operational at
a test area, delivering electron beam of 100 keV. We discuss beam
dynamics and analytical calculations leading to optimal parameters
of analysing section of LEBT line and RF deflector cavity that will
be used for measuring longitudinal characteristics for the low
energy electron beam.
Berry phase with tunable topological charge in Sagnac interferometer
Authors: Srinivasan Hemanth , Viswanathan Nirmal K
Published: February 2022

A Sagnac interferometer’s ring structure causes electromagnetic waves traversing it to periodically encounter the same optical elements. Due to this discrete translational symmetry, the frequency spectrum of the clockwise and counter-clockwise modes acquire a band structure with a characteristic band gap. When the interferometer is rotated, an additional non-reciprocal phase shift between the counter propagating modes arises and it results in the loss of time reversal symmetry. While prior understanding of the impact of Sagnac rotation on the band structure exists, the prevalence of topological geometric phase in Sagnac interferometer under rotation has not been prominently discussed. We propose a coupled mode theory with the required time reversal symmetry properties which influences the Berry curvature and we show that it leads to the accumulation of Berry phase with tunable topological charge.
Prognosis in dysphagic patients who are eating and drinking with acknowledged risk: results from the evaluation of the FORWARD project
Authors: Sommerville Peter , Hayton Jonathan , Soar Naomi , Archer Sally , Fitzgerald Adam , Lang Alex , Birns Jonathan
Published: February 2022

Background

patients with a permanently unsafe swallow may choose to eat and drink with acknowledged risk (EDAR). Informed decision-making and advance care planning depend on prognosis, but no data have yet been published on outcomes after EDAR decisions.

Methods

the study was undertaken in 555 hospital inpatients’ (mean [SD] age: 83 {12}) EDAR supported by the Feeding via the Oral Route with Acknowledged Risk of Deterioration care bundle between January 2015 and November 2019. Data were collected prospectively on clinical characteristics, dates of discharge, readmissions and death (where relevant). Kaplan-Meier survival functions and readmission risks per surviving patient per month were calculated.

Results

mortality is 56% in the first 3 months after discharge but then mortality risk sharply decreases. The 3-month survival in EDAR patients was more likely in those <75 years of age, those with Parkinson’s disease or a structural oral lesion as the dominating cause of dysphagia and those with mental capacity regarding EDAR decisions. Readmission risk in the 3 months post-discharge is 21% but reduces to 12% thereafter (P < 0.001). Thirty-eight percent of readmissions are secondary to EDAR-linked conditions such as chest infections and reduced oral intake.

Conclusion

there is a high mortality and readmission risk after an EDAR decision but much of this is frontloaded into the first 3 months, with a relatively favourable prognosis thereafter. This may be an appropriate time-point to reassess the plan for eating and drinking such that it continues to reflect the most appropriate balance of risk, comfort and nutrition.
Potential determinants of unfavourable healthcare utilisation trajectories during the last year of life of people with incident Alzheimer Disease or Related Syndromes: a nationwide cohort study using administrative data
Authors: Elyn Antoine , Gardette Virginie , Renoux Axel , Sourdet Sandrine , Nourhashemi Fati , Sanou Brigitte , Dutech Michel , Muller Philippe , Gallini Adeline
Published: February 2022

Background

people approaching the end-of-life frequently face inappropriate care. With Alzheimer Disease or Related Syndromes (ADRS), end-of-life is characterised by progressive decline, but this period remains difficult to identify. This leads to a lack of anticipation and sometimes with unfavourable healthcare utilisation trajectories (HUTs).

Objective

to quantify unfavourable HUTs during the last year of life and identify their potential determinants in both community and nursing-home settings.

Design

nationwide cohort study using administrative database.

Setting

French community and nursing-home residents.

Subjects

incident ADRS people identified in 2012, who died up to 31 December 2017.

Methods

we used multidimensional clustering to identify 15 clusters of HUTs, using 11 longitudinal healthcare dimensions during the last year of life. Clusters were qualitatively assessed by pluri-disciplinary experts as favourable or unfavourable HUTs. Individual and contextual potential determinants of unfavourable HUTs were studied by setting using logistic random-effect regression models.

Results

62,243 individuals died before 31 December 2017; 46.8% faced unfavourable end-of-life HUTs: 55.2% in the community and 31.8% in nursing-homes. Individual potential determinants were identified: younger age, male gender, ADRS identification through hospitalisation, shorter survival, life-limiting comorbidities, psychiatric disorders, acute hospitalisations and polypharmacy. In the community, deprivation and autonomy were identified as potential determinants. Contextual potential determinants raised mostly in the community, such as low nurse or physiotherapist accessibilities.

Conclusions

Nearly half of people with ADRS faced unfavourable HUTs during their last year of life. Individual potential determinants should help anticipate advance care planning and palliative care needs assessment. Contextual potential determinants suggest geographical disparities and health inequalities.