bluuebunny/crossref_metadata_2025 huggingface dataset:
Corrigendum to: Impacts of fire on soil organic carbon stocks in a grazed semi-arid tropical Australian savanna: accounting for landscape variability
Authors: Allen D. E. , Bloesch P. M. , Cowley R. A. , Orton T. G. , Payne J. E. , Dalal R. C.
Published: December 2021

Fire and grazing are commonplace in Australian tropical savannas and the effects of these management practices on soil organic carbon stocks (SOC) is not well understood. A long-term (20 years) experiment studying the effects of fire on a grazed semi-arid tropical savanna was used to increase this understanding. Treatments, including frequency of fire (every 2, 4 and 6 years), season of fire [early (June) vs late (October) dry season] and unburnt control plots, were imposed on Vertosol grassland and Calcarosol woodland sites, which were grazed. Additionally long-term enclosures [unburnt (except the Calcarosol in 2001) and ungrazed since 1973] on each soil type adjacent to each site were sampled, although not included in statistical analyses. SOC stocks were measured to a soil depth of 0.3m using a wet oxidation method (to avoid interference by carbonates) and compared on an equivalent soil mass basis. Significant treatment differences in SOC stocks were tested for, while accounting for spatial background variation within each site. SOC stocks (0–0.3m soil depth) ranged between 10.1 and 28.9tha–1 (Vertosol site) and 20.7 and 54.9tha–1 (Calcarosol site). There were no consistent effects of frequency or season of fire on SOC stocks, possibly reflecting the limited statistical power of the study and inherent spatial variability observed. Differences in the response to frequency and season of fire observed between these soils may have been due to differences in clay type, plant species composition and/or preferential grazing activity associated with fire management. There may also have been differences in C input between treatments and sites due to differences in the herbage mass and post-fire grazing activity on both sites and changed pasture composition, higher herbage fuel load, and a reduction in woody cover on the Vertosol site. This study demonstrated the importance of accounting for background spatial variability and treatment replication (in the absence of baseline values) when assessing SOC stocks in relation to management practices. Given the absence of baseline SOC values and the potentially long period required to obtain changes in SOC in rangelands, modelling of turnover of SOC in relation to background spatial variability would enable management scenarios to be considered in relation to landscape variation that may be unrelated to management. These considerations are important for reducing uncertainty in C-flux accounting and to provide accurate and cost-effective methods for land managers considering participation in the C economy.
¿Usté en Ciudá Real dice Madriz?
Authors: Kapović Marko
Published: December 2021

Abstracta

En este trabajo se estudia la variable realización de la -d en el final de palabra en la variedad de
Ciudad Real. Como una variedad transicional que se encuentra a medio camino entre las variedades fonéticamente innovadoras del sur y las
conservadoras del norte, la modalidad de Ciudad Real muestra características de ambas: con respecto a la variable en cuestión es la más
avanzada de las variedades castellanas, aunque no alcanza la categoricidad de la elisión de las hablas andaluzas. El proceso de la pérdida
de la -d final de palabra en Ciudad Real parece haber sido frenado en su fase final debido a las presiones desde arriba y
la situación se ha complicado adicionalmente con la aparición de la variante septentrional [θ], que se ha impuesto al alófono canónico [ð̞].
Aunque el contexto fónico siguiente es el predictor lingüístico más importante para la realización de -d
final de palabra, es asimismo muy llamativa la influencia del factor unidad léxica.
Central charges for AdS black holes
Authors: Perry Malcolm , Rodriguez Maria J
Published: December 2021

Nontrivial diffeomorphisms act on the horizon of a generic 4D black holes and create distinguishing features referred to as soft hair. Amongst these are a left–right pair of Virasoro algebras with associated charges that reproduce the Bekenstein–Hawking entropy for Kerr black holes. In this paper we show that if one adds a negative cosmological constant, there is a similar set of infinitesimal diffeomorphisms that act non-trivially on the horizon. The algebra of these diffeomorphisms gives rise to a central charge. Adding a boundary counterterm, justified to achieve integrability, leads to well-defined central charges with c
L = c
R. The macroscopic area law for Kerr-AdS black holes follows from the assumption of a Cardy formula governing the black hole microstates.
Inferring the gravitational binding energy and moment of inertia of PSR J0030 + 0451 and PSR J0740 + 6620 from new universal relations
Authors: Li Yuxi , Wang Jue , Wu Zehan , Wen Dehua
Published: December 2021

The neutron star interior composition explorer (NICER) recently simultaneously measured the gravitational mass (M
g) and radius (R) of PSR J0030 + 0451 and PSR J0740 + 6620, respectively. Inspired by the groundbreaking observations, we establish two high accuracy universal relations (with the relative error at 1% level) related to M
g and R to infer the gravitational binding energy (BE) (E
g) and moment of inertia (I) of the two pulsars. By combining these universal relations with the data of (M
g, R) released by NICER collaboration, the gravitational BE and moment of inertia of PSR J0030 + 0451 can be constrained within

|

E

g

|
=
0.2

1

−
0.03

+
0.03

M

⊙

and

I
=
1.9

5

−
0.50

+
0.70

×
1

0

45

g cm2 at 68% credible level, respectively. The gravitational BE and moment of inertia of PSR J0740 + 6620 can be constrained within

|

E

g

|
=
0.4

7

−
0.12

+
0.09

M

⊙

and

I
=
4.6

5

−
0.82

+
1.16

×
1

0

45

g cm2 at 68% credible level, respectively.
Darmois matching and C
3 matching
Authors: Gutiérrez-Piñeres Antonio C , Quevedo Hernando
Published: December 2021

We apply the Darmois and the C
3 matching conditions to three different spherically symmetric spacetimes. The exterior spacetime is described by the Schwarzschild vacuum solution whereas for the interior counterpart we choose different perfect fluid solutions with the same symmetry. We show that Darmois matching conditions are satisfied in all the three cases whereas the C
3 conditions are not fulfilled. We argue that this difference is due to a non-physical behavior of the pressure on the matching surface.
Angled beam expander telescopes for the Michelson beams in third generation gravitational wave observatories
Authors: DeSalvo Riccardo , Blow Jeremy , Bosque Claudio Pineda , Selleri Stefano
Published: December 2021

The third generation of gravitational wave detectors like the Einstein telescope or the cosmic explorer will be Michelson interferometers with Fabry–Perot cavities in the arms, using mirror test masses with diameter at the limit of technical feasibility. Unlike other detectors, the Einstein telescope will have a 60° angle between the arms. Because of its larger incidence angle, at any given beam size, it would require beam splitters almost double in size and much heavier than the 90° case. It is proposed here to install beam expander telescopes with angled mirrors located inside the Michelson interferometer between the Fabry–Perot cavities and the beam splitter. In addition to reducing the beam sizes and the beam splitter to manageable sizes, the proposed solution allows to bring the optimal recombination angle to 90°. The proposed geometry also offers a natural way to separate the beam splitters of different detectors into individual, smaller and more stable caverns thus improving observatory observation-time efficiency, to provide needed beam diagnostic points and convenient degrees of freedom for beam alignment into both the Fabry Perot cavities and the beam splitter, as well as to provide a method for maintaining optimal mode matching of the two arms onto the beam splitter without thermal compensation plates.
Light/electric modulated approach for logic functions and artificial synapse behaviors by flexible IGZO TFTs with low power consumption
Authors: Guo Liqiang , Zhang Guifa , Han Hui , Hu Yongbin , Cheng Guanggui
Published: December 2021

In recent years, low power electronic devices have attracted increasing interest. Here, flexible thin-film transistors (TFTs) with In–Ga–Zn–O (IGZO) as the semiconductor channel material were fabricated on polyethylene terephthalate substrates. The device exhibits good electrical properties at low operating voltage, including a high on/off ratio of ∼7.8 × 106 and high electron mobility of ∼23.1 cm2 V−1 s−1. The device also has an excellent response to visible light. With the increase of visible light intensity, the threshold voltage of IGZO TFTs decreases continuously, but the electron mobility increases gradually. Based on the unique ability of the device to respond to light, we proposed and demonstrated that a single TFT can realize different logic operations under the light/electricity mixed modulation, including ‘AND’ and ‘OR’. In addition, we also simulated some basic artificial synaptic behaviors, including excitatory postsynaptic current and paired-pulse facilitation. Thus, IGZO TFTs operating at low voltages not only have the potential to construct multifunctional optoelectronic devices, but also provide a new idea for simplifying the design of programmable logic circuits.
Characterisation of silicon oxynitride thin films and their response to swift heavy-ion irradiation
Authors: Mota-Santiago P , Nadzri A , Kremer F , Bierschenk T , Canto C E , Rodriguez M D , Notthoff C , Mudie S , Kluth P
Published: December 2021

Silicon oxynitrides (a-SiO
x
N
y
) are materials whose composition ranges between two binary materials: a-SiO2 and a-Si3N4. In this work, we present a systematic study of the fine structure of the damaged regions produced by swift heavy-ions (SHIs), or ‘ion-tracks’ and quantify the density variation profiles with respect to composition. Thin films were deposited by plasma-enhanced chemical vapor deposition (CVD), where thickness, density, stoichiometry and bond configuration were initially determined. The fine structure and radial size of the ion tracks was determined using small angle x-ray scattering. The tracks exhibit a core–shell cylindrical geometry, with an under-dense core surrounded by an over-dense shell with a smooth transition between the two regions. We observed two trends with composition: a constant increasing ion track radius is observed when the O/Si ratio is below one (

0
≤
x
≤
1
)

. And saturation of the radial dimensions above this value, being similar to a-SiO2. The IR spectra allowed to quantify the bond configuration and its evolution with fluence. After irradiation, the energy deposited by the SHI irradiation leads to a preferential damage of Si–N bonds. IR spectroscopy also showed the formation of new Si–H bonds with increasing fluences and resulting in a rather complex ion-induced structural modification of the a-SiO
x
N
y
network.
Non-Markovian transients in transport across chiral quantum wires using space–time non-equilibrium Green functions
Authors: Babu Nikhil Danny , Setlur Girish S
Published: December 2021

We study a system of two non-interacting quantum wires with fermions of opposite chirality with a point contact junction at the origin across which tunneling can take place when an arbitrary time-dependent bias between the wires is applied. We obtain the exact dynamical non-equilibrium Green function by solving Dyson’s equation analytically. Both the space–time dependent two and four-point functions are written down in a closed form in terms of simple functions of position and time. This allows us to obtain, among other things, the I–V characteristics for an arbitrary time-dependent bias. Our method is a superior alternative to competing approaches to non-equilibrium as we are able to account for transient phenomena as well as the steady state. We study the approach to steady state by computing the time evolution of the equal-time one-particle Green function. Our method can be easily applied to the problem of a double barrier contact whose internal properties can be adjusted to induce resonant tunneling leading to a conductance maximum. We then consider the case of a finite bandwidth in the point contact and calculate the non-equilibrium transport properties which exhibit non-Markovian behaviour. When a subsequently constant bias is suddenly switched on, the current shows a transient build up before approaching its steady state value in contrast to the infinite bandwidth case. This transient property is consistent with numerical simulations of lattice systems using time-dependent density matrix renormalization group suggesting thereby that this transient build up is merely due to the presence of a short distance cutoff in the problem description and not on the other details.
Phase transitions of liposomes: when light meets heat
Authors: Velez-Saboyá C S , Guzmán-Sepúlveda J R , Ruiz-Suárez J C
Published: December 2021

Phase transitions of liposomes are normally studied by differential scanning calorimetry. A suspension of liposomes is subjected to an increase (decrease) of temperature and when heat is absorbed (released), the liposomes transit from a gel (liquid) to a liquid (gel) phase. This endothermic (exothermic) process takes place at a temperature called the melting temperature T
m, which is distinctive of the type of lipids forming the vesicles. The vesicles, though, also modify their size in the transition. Indeed, the thickness of the membranes decreases (increases) because carbon tails misalign (align). Concomitant with the modifications in the membrane thickness, the diameter (D) of the liposomes changes too. Therefore, when they are inspected by light, the scattered signal carries information from such dilatation (contraction) process. We performed careful experiments using dynamic light scattering as a function of temperature to detect the size changes of different liposomes. Gaussian fits of the derivatives of the D vs T curves coincide within 1% with thermograms, which hints to the possibility of performing thermodynamic studies of lipid systems employing light.
Surface defect detection of vehicle light guide plates based on an improved RetinaNet
Authors: Li Junfeng , Wang Hao
Published: December 2021

Aiming at the vehicle navigation light guide plate (LGP) image characteristics, such as complex and gradient textures, uneven brightness, and small defects, this paper proposes a visual inspection method for LGP defects based on an improved RetinaNet. First, we use ResNeXt50 with higher accuracy under the same parameters as the backbone network, and propose the lightweight module Ghost_module to replace the 1 × 1 convolution in the lower half of the ResNeXt_block. This can reduce the resource parameters and consumption, and speed up training and inference. Second, we propose and use an improved feature pyramid network module to improve the feature fusion network in RetinaNet. It can more effectively fuse the shallow semantic information and high-level semantic information in the backbone feature extraction network, and further improve the detection ability of small target defects. Finally, the defect detection dataset constructed based on the vehicle LGP images collected at a industrial site, and experiments are performed on the vehicle LGP dataset and Aluminum Profile Defect Identification dataset (Aluminum Profile DID). The experimental results show that the proposed method is both efficient and effective. It achieves a better average detection rate of 98.6% on the vehicle LGP dataset. The accuracy and real-time performance can meet the requirements of industrial detection.
Investigating optimal region for thermal and electrical properties of epoxy nanocomposites under high frequencies and temperatures
Authors: Awais Muhammad , Chen Xiangrong , Dai Chao , Wang Qilong , Meng Fan-Bo , Hong Zelin , Paramane Ashish , Tanaka Yasuhiro
Published: December 2021

This research investigates the optimal region to achieve balanced thermal and electrical insulation properties of epoxy (EP) under high frequency (HF) and high temperature (HT) via integration of surface-modified hexagonal boron nitride (h-BN) nanoparticles. The effects of nanoparticle content and high temperature on various electrical (DC, AC, and high frequency) and thermal properties of EP are investigated. It is found that the nano h-BN addition enhances thermal performance and weakens electrical insulation properties. On the other side, under HF and HT stress, the presence of h-BN nanoparticles significantly improves the electrical performance of BN/EP nanocomposites. The EP has superior insulation properties at low temperature and low frequency, whereas the BN/EP nanocomposites exhibit better insulation performance than EP under HF and HT. The factors such as homogeneous nanoparticle dispersion in EP, enhanced thermal conductivity, nanoparticle surface modification, weight percent of nanoparticles, the mismatch between the relative permittivity of EP and nano h-BN, and the presence of voids in nanocomposites play the crucial role. The optimal nanoparticle content and homogenous dispersion can produce suitable EP composites for the high frequency and high temperature environment, particularly solid-state transformer applications.
Iterative dynamic dual-energy CT algorithm in reducing statistical noise in multi-energy CT imaging
Authors: Yao Yidi , Li Liang , Chen Zhiqiang
Published: December 2021

Multi-energy spectral CT has a broader range of applications with the recent development of photon-counting detectors. However, the photons counted in each energy bin decrease when the number of energy bins increases, which causes a higher statistical noise level of the CT image. In this work, we propose a novel iterative dynamic dual-energy CT algorithm to reduce the statistical noise. In the proposed algorithm, the multi-energy projections are estimated from the dynamic dual-energy CT data during the iterative process. The proposed algorithm is verified on sufficient numerical simulations and a laboratory two-energy-threshold PCD system. By applying the same reconstruction algorithm, the dynamic dual-energy CT’s final reconstruction results have a much lower statistical noise level than the conventional multi-energy CT. Moreover, based on the analysis of the simulation results, we explain why the dynamic dual-energy CT has a lower statistical noise level than the conventional multi-energy CT. The underlying idea is to sample sparse in the energy dimension, which can be done because there is a high correlation between projection data of different energy bins.
On the compact modelling of Si nanowire and Si nanosheet MOSFETs
Authors: Cerdeira A , Estrada M , Pavanello M A
Published: December 2021

In this paper, three-dimensional technology computer aided design simulations are used to show that the electron concentration, current density, and electric field distribution from the interface at the lateral channels and from the top channel to the centre of the silicon wire, in nanowire and nanosheet structures, are practically same. This characteristic makes it possible to consider that the total channel width for these structures is equal to the perimeter of the transistor sheet, allowing to extend of the application of the symmetric doped double-gate model (SDDGM) model to nanowires and nanosheets metal-oxide-semiconductor field effect transistors, with no need to include new parameters. The model SDDGM is validated for this application using several measured and simulated structures of nanowires and nanosheets transistors, with different aspect ratios of fin width and fin height, showing very good agreement between measured or simulated characteristics and modelled. SDDGM is encoded in Verilog-A language and implemented in the SmartSPICE circuit simulator.
Superconducting NbN thin films on various (X/Y/Z-cut) lithium niobate substrates
Authors: Si Mengting , Wang Chengli , Yang Can , Peng Wei , You Lixing , Li Zhongxu , Zhang Hui , Huang Jia , Xiao You , Xiong Jiamin , Zhang Lu , Pan Yiming , Ou Xin , Wang Zhen
Published: December 2021

Lithium niobate (LN) exhibits outstanding properties in various application of photonics, electronics, and optoelectronics, showing potentials in integration. Due to the directional dependence of LN tensor properties, optical elements made up by LN favor the type of LN substrate. To introduce high-performance superconducting nanowire single-photon detectors (SNSPDs) to LN-integrated photonics chips, superconducting NbN thin films with thicknesses from 3 to 50 nm were deposited on X-cut, Y-cut, and Z-cut LN substrates using magnetron sputtering at room temperature. The different thickness dependencies of T
c, δT
c, and residual resistance ratios are observed in NbN thin films on different LN substrates. NbN thin films on X-cut and Y-cut LN substrates are polycrystalline with a transition temperature (T
c) of ∼6 K for a 6 nm thick film. While NbN thin films are epitaxially textured on Z-cut LN substrates with T
c of 11.5 K for a 6 nm thick film. NbN-SNSPD on X-cut LN substrates shows a weak saturation trend of its system detection efficiency; however, the performance of NbN-SNSPD on Z-cut LN substrates is limited. We evaluated the selection of cuts and concluded that X-cut and Y-cut LN are more suitable to be a platform of integrated LN photonic chips from the aspect of NbN-SNSPD. This study helps fabricate high-performance SNSPDs on fully integrated photonics chips on LN substrates.
Highly ordered nanoscale phosphomolybdate-grafted polyaniline/metal hybrid layered structures prepared via secondary sputtering phenomenon as high-performance pseudocapacitor electrodes
Authors: Yoon Eun Seop , Choi Bong Gill , Jeon Hwan-Jin
Published: December 2021

The development of energy storage electrode materials is important for enhancing the electrochemical performance of supercapacitors. Despite extensive research on improving electrochemical performance with polymer-based materials, electrode materials with micro/nanostructures are needed for fast and efficient ion and electron transfer. In this work, highly ordered phosphomolybdate (PMoO)-grafted polyaniline (PMoO-PAI) deposited onto Au hole-cylinder nanopillar arrays is developed for high-performance pseudocapacitors. The three-dimensional nanostructured arrays are easily fabricated by secondary sputtering lithography, which has recently gained attention and features a high resolution of 10 nm, a high aspect ratio greater than 20, excellent uniformity/accuracy/precision, and compatibility with large area substrates. These 10 nm scale Au nanostructures with a high aspect ratio of ∼30 on Au substrates facilitate efficient ion and electron transfer. The resultant PMoO-PAI electrode exhibits outstanding electrochemical performance, including a high specific capacitance of 114 mF cm−2, a high-rate capability of 88%, and excellent long-term stability.
Radiation effect on three-dimensional stagnation point flow involving copper-aqueous titania hybrid nanofluid induced by a non-Fourier heat flux over a horizontal plane surface
Authors: Khan Umair , Zaib A , Ishak A , Bakar S Abu , Sherif El-Sayed M , Muhammad Noor
Published: December 2021

This research numerically investigates 3D stagnation-point flow (SPF) past a horizontal plane surface conveying copper-aqueous titania hybrid nanofluid induced by non-Fourier heat flux (NFHF) that utilized in heat transfer processes. A Tiwari-Das model is engaged to examine the fluid flow dynamics and the heat transfer features of the hybrid nanofluid with thermal radiation effect. With aid of similarity variables, the leading nonlinear system involving partial differential equations (PDEs) is reduced to a system of ordinary differential equations (ODEs). This set of dimensionless coupled ODEs is then tackled through the bvp4c solver in MATLAB. For hybrid nanofluid, the graphical findings of the pertaining parameters as well as the saddle/nodal indicative parameter are disclosed and explained with the assist of figures and tables. The results illustrate that the rise of hybrid nanoparticles declines the motion of the fluids in both axes of coordinates (

x
−

and

y
−

directions), while the temperature enhances. In addition, the temperature distribution declines due to relaxation parameter but uplifts due to radiation. Also, the thermal relaxation parameter reduces the temperature. Moreover, the present solution displays an excellent agreement with earlier published works in the limited cases of normal fluid and nanofluid.
Analytical calculation of the parameters of light bullets propagating in the tunnel ionization regime
Authors: Bugay Aleksandr N , Khalyapin Vyacheslav A
Published: December 2021

Analytic estimation of the parameters of light bullets formed in the anomalous group dispersion region of transparent dielectrics under conditions of tunneling photoionization was performed. For this purpose, the system of the ordinary differential equations for the laser pulse’s parameters such as amplitude, temporal duration, chirp parameter, temporal delay, frequency shift, radius and curvature were obtained. The stationary solution of this system and conditions of the quasi-stable regime of propagation were found.
Measurements of charge sharing in a hybrid pixel photon counting CdTe detector
Authors: Krzyzanowska A.
Published: December 2021

Hybrid pixel radiation detectors working in a single-photon counting mode have gained increasing attention due to their noiseless imaging and high dynamic range. Due to the fact that sensors of different materials can be attached to the readout circuit, they allow operation with a wide range of photon energies. The performance of the single photon counting detectors is limited by pile-up. To allow a detector to work under high flux conditions, the pixel size is reduced, which minimizes detector dead time. However, with smaller pixel sizes the charge sharing effect, a phenomenon that deteriorates both detection efficiency and spatial resolution is more profound.

The influence of charge sharing on the detector performance can be quantified using parameterization of the s-curve obtained in the spectral response measurements. The article presents the measurements of the response function of a hybrid pixelated photon counting detector for certain primary energy, which corresponds to the probability of detecting a photon as a function of its energy deposition. The measurements were carried out using an X-ray tube by performing a threshold scan during illumination with X-ray photons of a 1.5 mm and 0.75 mm thick CdTe detector with 100 µm pixel pitch. The charge size cloud depends on the sensor material, the bias voltage, and the sensor thickness. Therefore, the experimental data from a sensor biased with different bias voltages are compared to the theoretical results based on a cascaded model of a single-photon counting segmented silicon detector. The study of the charge sharing influence on the spatial resolution of the CdTe detector will serve for a further study of the possible implementations of the algorithms achieving subpixel resolution, in which the charge sharing becomes the desired effect since the charge division in the pixels is used to interpolate the photon interaction position.
Studies of high-field QED with the LUXE experiment at the European XFEL
Authors: Borysova M.
Published: December 2021

The LUXE experiment aims at studying high-field QED in electron-laser and photon-laser interactions, with the 16.5 GeV electron beam of the European XFEL and a laser beam with power of up to 350 TW. The experiment will measure the spectra of electrons and photons in non-linear Compton scattering where production rates in excess of 109 are expected per 1 Hz bunch crossing. At the same time positrons from pair creation in either the two-step trident process or the Breit-Wheeler process will be measured, where the expected rates range from 10−3 to 104 per bunch crossing, depending on the laser power and focus. These measurements have to be performed in the presence of low-energy high radiation-background. To meet these challenges, for high-rate electron and photon fluxes, the experiment will use Cherenkov radiation detectors, scintillator screens, sapphire sensors as well as lead-glass monitors for back-scattering off the beam-dump. A four-layer silicon-pixel tracker and a compact sampling electromagnetic calorimeter will be used to measure the positron spectra. The layout of the experiment and the expected performance under the harsh radiation conditions will be presented.
On the use of neural networks for energy reconstruction in high-granularity calorimeters
Authors: Akchurin N. , Cowden C. , Damgov J. , Hussain A. , Kunori S.
Published: December 2021

We contrasted the performance of deep neural networks —
Convolutional Neural Network (CNN) and Graph Neural Network (GNN)
— to current state of the art energy regression methods in a
finely 3D-segmented calorimeter simulated by GEANT4. This
comparative benchmark gives us some insight to assess the particular
latent signals neural network methods exploit to achieve superior
resolution. A CNN trained solely on a pure sample of pions achieved
substantial improvement in the energy resolution for both single
pions and jets over the conventional approaches. It maintained good
performance for electron and photon reconstruction. We also used
the Graph Neural Network (GNN) with edge convolution to assess the
importance of timing information in the shower development for
improved energy reconstruction. We implement a simple simulation
based correction to the energy sum derived from the fraction of
energy deposited in the electromagnetic shower component. This
serves as an approximate dual-readout analogue for our benchmark
comparison. Although this study does not include the simulation of
detector effects, such as electronic noise, the margin of
improvement seems robust enough to suggest these benefits will
endure in real-world application. We also find reason to infer that
the CNN/GNN methods leverage latent features that concur with our
current understanding of the physics of calorimeter measurement.
Numerical modeling of a proton spin-flipping system in the spin transparency mode at an integer spin resonance in JINR's Nuclotron
Authors: Filatov Yu.N. , Kondratenko A.M. , Kondratenko M.A. , Vorobyov V.V. , Vinogradov S.V. , Tsyplakov E.D. , Butenko A.V. , Syresin E.M. , Kostromin S.A. , Derbenev Ya.S. , Morozov V.S.
Published: December 2021

In this paper we propose a lattice insertion for the Nuclotron ring called a “spin navigator” that can adjust any direction of the proton polarization in the orbital plane using weak solenoids. The polarization control is realized in the spin transparency mode at the energy of 108 MeV, which corresponds to the integer spin resonance γ G = 2. The requirements on the navigator solenoid fields are specified considering the criteria for stability of the spin motion during any manipulation of the polarization direction in an experiment. The paper presents the results of numerical modeling of the proton spin dynamics in the Nuclotron ring operated in the spin transparency mode. The verified spin navigator is aimed at an experimental study of a spin-flipping system using the Nuclotron ring. The results are relevant to the NICA (JINR), EIC (BNL) and COSY (FZJ) facilities where the spin transparency mode can be applied for polarization control.
Crab-inspired compliant leg design method for adaptive locomotion of a multi-legged robot
Authors: Zhang Jun , Liu Qi , Zhou Jingsong , Song Aiguo
Published: December 2021

Chinese mitten crab has unique limb structures composed of a hard exoskeleton and flexible muscles. They enable the crab to locomote adaptively and safely on various terrains. In this work, we investigated the limb structures, motion principle, and gaits of the crab using a high-speed camera and a press machine. Then, a novel compliant robot leg design method is proposed, inspired by the crab limb. The leg comprises six hard scleromeres and a flexible thin-wall spring steel sheet (FSSS) mimicking the exoskeleton and muscle. The scleromeres connected one by one with rotational joints are designed with slots. The front end of the FSSS is fixed on the scleromere close to the ground. The rear end crosses the slots and is mounted at the shaft of a linear actuator installed at the rear scleromere. The leg bends and stretches when the actuator pushes and pulls the FSSS, respectively. The kinematic modeling, rigid-flexible coupling dynamic simulations, and leg prototype tests are conducted, which verify the leg design approach. Thirdly, we put forward a multi-legged robot with eight compliant legs and design its gait using the gaits of the crab. Finally, the robot’s performance is evaluated, including the capabilities of walking on different terrains at adjustable speeds and body heights, traversing low channels, walking on slopes, and carrying loads. The results prove that the single-motor-actuated compliant legs and their dynamic coupling with the rigid robot body frame can enable them to have the ground clearance ability and realize the adaptive walking of the robot. The leg design methodology can be used to design multi-legged robots with the merits of compact, light, low mechanical complexity, high safety, and easy to control, for many applications, such as environmental monitoring, search and rescue.
Exploiting maleimide-functionalized hyaluronan hydrogels to test cellular responses to physical and biochemical stimuli
Authors: Mazzocchi Andrea , Yoo Kyung Min , Nairon Kylie G , Kirk L Madison , Rahbar Elaheh , Soker Shay , Skardal Aleksander
Published: December 2021

Current in vitro three-dimensional (3D) models of liver tissue have been limited by the inability to study the effects of specific extracellular matrix (ECM) components on cell phenotypes. This is in part due to limitations in the availability of chemical modifications appropriate for this purpose. For example, hyaluronic acid (HA), which is a natural ECM component within the liver, lacks key ECM motifs (e.g. arginine–glycine–aspartic acid (RGD) peptides) that support cell adhesion. However, the addition of maleimide (Mal) groups to HA could facilitate the conjugation of ECM biomimetic peptides with thiol-containing end groups. In this study, we characterized a new crosslinkable hydrogel (i.e. HA-Mal) that yielded a simplified ECM-mimicking microenvironment supportive of 3D liver cell culture. We then performed a series of experiments to assess the impact of physical and biochemical signaling in the form of RGD peptide incorporation and transforming growth factor ß (TGF-ß) supplementation, respectively, on hepatic functionality. Hepatic stellate cells (i.e. LX-2) exhibited increased cell–matrix interactions in the form of cell spreading and elongation within HA-Mal matrices containing RGD peptides, enabling physical adhesions, whereas hepatocyte-like cells (HepG2) had reduced albumin and urea production. We further exposed the encapsulated cells to soluble TGF-ß to elicit a fibrosis-like state. In the presence of TGF-ß biochemical signals, LX-2 cells became activated and HepG2 functionality significantly decreased in both RGD-containing and RGD-free hydrogels. Altogether, in this study we have developed a hydrogel biomaterial platform that allows for discrete manipulation of specific ECM motifs within the hydrogel to better understand the roles of cell–matrix interactions on cell phenotype and overall liver functionality.
Optimized, visible light-induced crosslinkable hybrid gelatin/hyaluronic acid scaffold promotes complete spinal cord injury repair
Authors: Zhao Xinhao , Wang Huiru , Zou Yunlong , Xue Weiwei , Zhuang Yang , Gu Rui , Shen He , Dai Jianwu
Published: December 2021

Severe microenvironmental changes after spinal cord injury (SCI) present serious challenges in neural regeneration and tissue repair. Gelatin (GL)- and hyaluronic acid (HA)-based hydrogels are attractive scaffolds because they are major components of the extracellular matrix and can provide a favorable adjustable microenvironment for neurogenesis and motor function recovery. In this study, three-dimensional hybrid GL/HA hydrogel scaffolds were prepared and optimized. The hybrid hydrogels could undergo in situ gelation and fit the defects perfectly via visible light-induced crosslinking in the complete SCI rats. We found that the transplantation of the hybrid hydrogel scaffold significantly reduced the inflammatory responses and suppressed glial scar formation in an HA concentration-dependent manner. Moreover, the hybrid hydrogel with GL/HA ratios less than 8/2 effectively promoted endogenous neural stem cell migration and neurogenesis, as well as improved neuron maturation and axonal regeneration. The results showed locomotor function improved 60 days after transplantation, thus suggesting that GL/HA hydrogels can be considered as a promising scaffold for complete SCI repair.
Multifractal analysis of ultrasonically machined surfaces of cylindrical quartz crystals: the effect of the abrasive grits
Authors: Ţălu Ştefan , Guzzo Pedro L , Astinchap Bandar , Ghanbaripour Hamta
Published: December 2021

Since synthetic quartz is essential to produce 3D resonators for numerous applications in precision electronics, in this work the surface topography of cylindrical quartz bars is investigated using the multifractal technique. The cylindrical bars were manufactured with ultrasonic machining using five SiC grits ranging from 6 to 50 μm. The machined surfaces were initially characterized by contact profilometry and scanning electron microscopy (SEM). The multifractality of the machined surfaces was scrutinized using a box-counting method applied to the images obtained with 500X magnification. The multifractal spectrum indicated that the fractal dimension f(α) and the width of the fractal spectrum Δα are dependent on the grit size, but this dependence is not monotonic. The lowest (negative) value for Δf(α) was found for 25 μm grits indicating that for these grits the lower frequency events (grooves with tens μm width occurring along the USM direction) control the surface topography much more than high-frequency events related to brittle microcracking. The abrasive wear due to the continuous slurry recycling in lateral tool-workpiece interfaces contributed to smooth the groove texture as well as the sharpness of microscopic indentations, which remained observed on the surfaces machined with 50 μm grits. The opposite paths observed for the arithmetical mean deviation of the measured profile (Ra) and Δf(α) parameters with the cutting rate measured for each grit size were valuable to differentiate flat-rough and unlevelled-rough topographies in quartz bars.
Picture this
Authors: Hiscott Laura
Published: December 2021

Laura Hiscott reviews 99 Maps to Save the Planet by KATAPULT
The climate-change outsider
Authors: Perkowitz Sidney
Published: December 2021

Climate science has a long and multidisciplinary history, with contributions from scientists both within and outside academia.
Prize endeavours
Authors: Durrani Matin
Published: December 2021

Climate physics has at long last been recognized with a Nobel prize.
Help me if you can
Authors: McKenzie James
Published: December 2021

In his latest article on funding hi-tech firms, James McKenzie looks at the help on offer for businesses to innovate and grow.
Clearing the bar
Authors: Atkins Chris
Published: December 2021

A clarification on the letter “The missing mass”, concerning the pole vault in question 8 of the decathlon puzzle “Sporting chance”.
Sterile neutrinos ruled out by MicroBooNE experiment
Authors: Johnston Hamish
Published: December 2021

The first results from the Micro-BooNE neutrino detector at Fermilab in the US suggest that the mysterious signals seen in two other neutrino detectors are not the result of hypothetical particles called sterile neutrinos.
The quantum revolution
Authors: Durrani Matin
Published: December 2021

Welcome to this special issue celebrating the rise of quantum technologies.
Explicit Vologodsky integration for hyperelliptic curves
Authors: Kaya Enis
Published: December 2021

Vologodsky’s theory of

p
p

-adic integration plays a central role in computing several interesting invariants in arithmetic geometry [Mosc. Math. J. 3 (2003), pp. 205–247, 260]. In contrast with the theory developed by Coleman [Invent. Math. 69 (1982), pp. 171–208; Duke Math. J. 52 (1985), pp. 765–770; Ann. of Math. (2) 121 (1985), pp. 111–168; Invent. Math. 93 (1988), pp. 239-266], it has the advantage of being insensitive to the reduction type at

p
p

. Building on recent work of Besser and Zerbes [Vologodsky integration on curves with semi-stable reduction, to appear in Israel J. Math], we describe an algorithm for computing Vologodsky integrals on bad reduction hyperelliptic curves. This extends previous joint work with Katz [Int. Math. Res. Not. IMRN 8 (2022), pp. 6038–6106] to all meromorphic differential forms. We illustrate our algorithm with numerical examples computed in Sage.
Sutured ECH is a natural invariant
Authors: Kutluhan Çağatay , Sivek Steven , Taubes C.
Published: December 2021

We show that sutured embedded contact homology is a natural invariant of sutured contact33-manifolds which can potentially detect some of the topology of the space of contact structures on a33-manifold with boundary. The appendix, by C. H. Taubes, proves a compactness result for the completion of a sutured contact33-manifold in the context of Seiberg–Witten Floer homology, which enables us to complete the proof of naturality.
The Oxford Encyclopedia of Curriculum Studies
Authors: Schubert William H. , He Ming Fang
Published: December 2021

115 entries

The Oxford Encyclopedia of Curriculum Studies (OECS) addresses the central question of Curriculum Studies as: What is worthwhile? The articles show how the public, personal and educational concerns about composing lives are the essence of curriculum. Writ large, Curriculum Studies pertains to what human beings should know, need, experience, do, be, become, overcome, contribute, share, wonder, imagine, invent, and improve. While the OECS treats curriculum as definitely central to schooling, it also shows how curriculum scholars also work on myriad other institutionalized and non-institutionalized dimensions of life that shape the ways humans learn to perceive, conceptualize, and act in the world. Thus, while OECS treats perennial curriculum categories (e.g., curriculum theory, history, purposes, development, design, enactment, evaluation), it does so through a critical eye that provides counter-narratives to neoliberal, colonial, and imperial forces that have too often dominated curriculum thought, policy, and practice. Thus, OECS presents contemporary perspectives on prevailing topics such as science, mathematics, social studies, literacy/reading/literature/language arts, music, art, physical education, testing, special education, liberal arts, many OECS articles also show how curriculum is embedded in ideology, human rights, mythology, museums, media, literature/film, geographical spaces, community organizing, social movements, cultures, race relations, gender, social class, immigration, activist work, popular pedagogy, revolution, diasporic events, and much more. To provide such perspectives, articles draw upon diverse scholarly traditions in addition to (though including) established qualitative and quantitative approaches (e.g., feminist, womanist, oral, critical theory, critical race theory, critical dis/ability studies, Indigenous ways of knowing, documentary, dialogue, postmodern, cooperative, posthuman, and diverse modes of expression). Moreover, such orientations (often drawn from neglected work Asia, the Global South, Aboriginal regions, and other often excluded realms) reveal positions that counter official or dominant neo-liberal impositions by emphasizing hidden, null, outside, material, embodied, lived, and transgressive curricula that foster emancipatory, ecologically interdependent, and continuously growing constructs.
Darwin’s and Wallace’s Fascinations With Oversized Morphology and the Question of Developmental Plasticity
Authors: Kawano Kazuo
Published: December 2021

Darwin in his book, The Descent of Man and Selection in Relation to Sex, described his fascination with a male Chiasognathus grantii Stephens (Coreptera, Lucanidae), a stag beetle species with enormous mandibles. Wallace in his book, The Malay Archipelago, recorded his enchantment with a male Euchirus longimanus L. (Coreptera, Scarabaeoidae), a ‘chafer’ species with ‘immense fore-arms’ (tibia or femora). These oversized traits have been interpreted as the results of allometry through sexual selection. Both Darwin and Wallace were aware that there was a large variation in these oversized traits intraspecifically, leading to the question of the role of variability in species-level evolution. To answer this question, I studied the variation in developmental plasticity (DP; the individual ability to react to external environment) of the stag beetles, which shows a great variation in external morphology. These observations indicated that 1) DP (measured in body length) is independent of allometry of the mandibles, 2) allometry of the mandibles had been ingrained in most members of the Family before the differentiation of DP took place, 3) DP is indirectly related to sexual selection through elongated mandibles that are used for fighting or securing the mate, as evidenced by the close correlation of DP with the mandible length, and 4) the enormous mandibles of stag beetles are the product of enlarged DP through allometry and sexual selection. From these results, I add enhanced DP as an independent element in the evolution of seemingly oversized traits seen in many beetle species.
Baicalein-ameliorated cerebral ischemia-reperfusion injury dependent on calpain 1/AIF pathway
Authors: Li Shanshan , Zhang Yaoshuai , Fei Lili , Zhang Yuhan , Pang Jinlong , Gao Wei , Fan Fangtian , Xing Yadong , Li Xian
Published: December 2021

Cerebral ischemia reperfusion (CIR) has become the leading cause of death and disability. Baicalein is a natural bioactive ingredient extracted from Scutellaria baicalensis Georgi and has neuroprotective activity. In our work, baicalein was found to reduce neurological deficits, brain water content, infarct area, and neuronal death of rats induced by middle cerebral artery occlusion/reperfusion. In vitro, oxygen–glucose deprivation/reperfusion induced inordinate ROS production and apoptosis that could be reversed by baicalein. Our study revealed for the first time that baicalein has the potential to bind and inhibit the activity of calpain 1, thereby inhibiting AIF nuclear translocation. These findings demonstrated that baicalein protected against CIR injury via inhibiting AIF nuclear translocation by inhibiting calpain 1 activity.