bluuebunny/crossref_metadata_2025 huggingface dataset:
Association between COVID-19 restrictions and emergency department presentations for paediatric mental health in Victoria, Australia
Authors: Hiscock Harriet , Chu Wanyu , O’Reilly Gerard , Freed Gary L , White Mary , Danchin Margie , Craig Simon
Published: July 2022

Objective To determine the association between coronavirus disease 2019 (COVID-19) restrictions and paediatric mental health emergency department presentations. Methods Secondary analysis of Victorian Emergency Minimum Dataset data from 38 Victorian public hospital emergency departments. Paediatric patients (birth to <18 years) attending emergency departments with an International Classification of Disease-Australian Modification (ICD-10-AM) diagnosis of a mental health problem between 1 January 2018 and 31 October 2020 were included. We compared pre-COVID-19 (1 January 2018–27 March 2020) to the COVID-19 period (28 March–26 October 2020) to examine the number of mental health presentations by patient age, socioeconomic status, location, and emergency department triage category. A Poisson regression prediction model was built for each diagnosis group to predict the presentation number in the COVID-19 period, assuming the pandemic and associated restrictions had not happened. Results There were 15 898 presentations (589 presentations/month on average) in the pre-COVID-19 period and 4747 presentations (678 presentations/month on average) in the COVID-19 period. Compared with predicted presentations, there was an increase in observed presentations for eating disorders throughout lockdown (on average, an increase of 36 presentations/month) and for anxiety (11/month) and self-harm (18/month). There were no meaningful changes for mood disorders or developmental and behavioural problems, and presentations for substance abuse mostly fell. Conclusions Pandemic restrictions were associated with increased emergency department presentations for eating disorders and, to a lesser extent, anxiety and self-harm. Given the ongoing pandemic, clinicians and policy makers must work together to find timely, accessible solutions to better manage these conditions.
Learning from successful long-term citizen science programs
Authors: Hansen Birgita , Bonney Patrick
Published: July 2022

Citizen science is increasingly recognised as an important, indeed necessary, contribution to environmental research and policy, as well as for fostering stronger relationships between scientists and the broader community. Well-established citizen science projects offer valuable insights by virtue of the long-term contribution of volunteers to sustained research and monitoring activities. Here we draw on two of Australia’s longest running citizen science projects, Waterwatch and the Australian Shorebird Monitoring Program (formerly Shorebirds 2020), to argue that such projects reflect successful citizen science in terms of their program persistence, reputation and impact. This success has been enabled by (1) developing a clear vision; (2) effective knowledge management; (3) relationship building; (4) meaningful volunteer engagement; and (5) a capacity to adapt to change. We recommend that new and emerging projects embed these principles in their program development, particularly those aiming to generate longitudinal datasets while building motivated, informed and connected communities.
Cuts through the manifold of molecular H
2
O potential energy surfaces in liquid water at ambient conditions
Authors: Pietzsch Annette , Niskanen Johannes , Vaz da Cruz Vinicius , Büchner Robby , Eckert Sebastian , Fondell Mattis , Jay Raphael M. , Lu Xingye , McNally Daniel , Schmitt Thorsten , Föhlisch Alexander
Published: July 2022

The fluctuating hydrogen bridge bonded network of liquid water at ambient conditions entails a varied ensemble of the underlying constituting H
2
O molecular moieties. This is mirrored in a manifold of the H
2
O molecular potentials. Subnatural line width resonant inelastic X-ray scattering allowed us to quantify the manifold of molecular potential energy surfaces along the H
2
O symmetric normal mode and the local asymmetric O–H bond coordinate up to 1 and 1.5 Å, respectively. The comparison of the single H
2
O molecular potentials and spectroscopic signatures with the ambient conditions liquid phase H
2
O molecular potentials is done on various levels. In the gas phase, first principles, Morse potentials, and stepwise harmonic potential reconstruction have been employed and benchmarked. In the liquid phase the determination of the potential energy manifold along the local asymmetric O–H bond coordinate from resonant inelastic X-ray scattering via the bound state oxygen 1
s
to

4

a
1

resonance is treated within these frameworks. The potential energy surface manifold along the symmetric stretch from resonant inelastic X-ray scattering via the oxygen 1
s
to

2

b
2

resonance is based on stepwise harmonic reconstruction. We find in liquid water at ambient conditions H
2
O molecular potentials ranging from the weak interaction limit to strongly distorted potentials which are put into perspective to established parameters, i.e., intermolecular O–H, H–H, and O–O correlation lengths from neutron scattering.
Phase-separating RNA-binding proteins form heterogeneous distributions of clusters in subsaturated solutions
Authors: Kar Mrityunjoy , Dar Furqan , Welsh Timothy J. , Vogel Laura T. , Kühnemuth Ralf , Majumdar Anupa , Krainer Georg , Franzmann Titus M. , Alberti Simon , Seidel Claus A. M. , Knowles Tuomas P. J. , Hyman Anthony A. , Pappu Rohit V.
Published: July 2022

Macromolecular phase separation is thought to be one of the processes that drives the formation of membraneless biomolecular condensates in cells. The dynamics of phase separation are thought to follow the tenets of classical nucleation theory, and, therefore, subsaturated solutions should be devoid of clusters with more than a few molecules. We tested this prediction using in vitro biophysical studies to characterize subsaturated solutions of phase-separating RNA-binding proteins with intrinsically disordered prion-like domains and RNA-binding domains. Surprisingly, and in direct contradiction to expectations from classical nucleation theory, we find that subsaturated solutions are characterized by the presence of heterogeneous distributions of clusters. The distributions of cluster sizes, which are dominated by small species, shift continuously toward larger sizes as protein concentrations increase and approach the saturation concentration. As a result, many of the clusters encompass tens to hundreds of molecules, while less than 1% of the solutions are mesoscale species that are several hundred nanometers in diameter. We find that cluster formation in subsaturated solutions and phase separation in supersaturated solutions are strongly coupled via sequence-encoded interactions. We also find that cluster formation and phase separation can be decoupled using solutes as well as specific sets of mutations. Our findings, which are concordant with predictions for associative polymers, implicate an interplay between networks of sequence-specific and solubility-determining interactions that, respectively, govern cluster formation in subsaturated solutions and the saturation concentrations above which phase separation occurs.
ABA represses TOR and root meristem activity through nuclear exit of the SnRK1 kinase
Authors: Belda-Palazón Borja , Costa Mónica , Beeckman Tom , Rolland Filip , Baena-González Elena
Published: July 2022

The phytohormone abscisic acid (ABA) promotes plant tolerance to major stresses such as drought, partly by modulating growth through poorly understood mechanisms. Here, we show that ABA-triggered repression of cell proliferation in the
Arabidopsis thaliana
root meristem relies on the swift subcellular relocalization of SNF1-RELATED KINASE 1 (SnRK1). Under favorable conditions, the SnRK1 catalytic subunit, SnRK1α1, is enriched in the nuclei of root cells, and this is accompanied by normal cell proliferation and meristem size. Depletion of two key drivers of ABA signaling, SnRK2.2 and SnRK2.3, causes constitutive cytoplasmic localization of SnRK1α1 and reduced meristem size, suggesting that, under nonstress conditions, SnRK2s promote growth by retaining SnRK1α1 in the nucleus. In response to ABA, SnRK1α1 translocates to the cytoplasm, and this is accompanied by inhibition of target of rapamycin (TOR), decreased cell proliferation, and reduced meristem size. Blocking nuclear export with leptomycin B abrogates ABA-driven SnRK1α1 relocalization to the cytoplasm and ABA-elicited inhibition of TOR. Furthermore, fusing SnRK1α1 to an SV40 nuclear localization signal leads to defective ABA-dependent TOR repression. Altogether, we demonstrate that SnRK2-dependent changes in SnRK1α1 subcellular localization are crucial for inhibiting TOR and root growth in response to ABA. Rapid relocalization of central regulators such as SnRK1 may represent a general strategy of eukaryotic organisms to respond to environmental changes.
Charting the meningeal lymphatic network
Authors: Da Mesquita Sandro
Published: July 2022

A genuine network of lymphatic vessels can be found in the dural layer of the meninges that ensheathe the brain and spinal cord of mammalians. In this issue, Jacob et al. (2022. J. Exp. Med.https://doi.org/10.1084/jem.20220035) employ light sheet fluorescence imaging of intact mouse heads to provide a more comprehensive chart of the meningeal lymphatic vasculature and draw a parallel between lymphatic drainage of cerebrospinal fluid in mice and humans.
Forces on hockey players and conservation laws: on the theoretical efficiency of different techniques
Authors: Persson Rasmus A X
Published: July 2022

With a more comprehensive, yet still idealized, take on the analysis by Nässén et al (2019 Eur. J. Phys.
40 065005) regarding the efficiency of different ice skating strides, we find no superiority of the ‘angular momentum skating’ technique within their model. The fundamental reason is that for the ‘angular momentum stride’, there is a force component opposing the forward motion during the latter part of the stride, but not so for the traditional skating technique. We conclude with a short pedagogical discussion regarding conservation laws in physics.
An application of the Lyapunov stability theorem: a bead on a rotating hoop
Authors: Cao Yuxuan , Zhou Wenquan , Jiang Jiangang
Published: July 2022

The motion of a bead on a rotating hoop is a classical problem in mechanics. The problem describes that a bead is placed on the track of a hoop rotating around a vertical axis. Although this issue is researched by lots of scholars, this system is usually analyzed without considering the friction. However, when considering friction, it becomes difficult to analyze the stability. The purpose of this study is to investigate the stability of the system with friction more easily. We derive the equation of motion of the bead and use the Lyapunov stability theorem to analyze the stability. The stability is determined by the angular velocity of the hoop. If the angular velocity is less than or equal to the critical value the bead is asymptotically stable at origin (the bottom of the hoop) otherwise it is asymptotically stable at a non-zero position. In addition, we study the difference between mass point bead and rigid body bead and find that both have identical bifurcation diagram and stability, whereas the trajectories have a difference on the phase plane. In the end, the numerical simulation method is used to verify the conclusion above.
Quantum carpets in leaky boxes
Authors: Berry M V
Published: July 2022

Quantum waves evolving or propagating inside one-dimensional boxes generate ‘quantum carpets’: intricate patterns in spacetime. The formally equivalent patterns in classical paraxial optics are observed as the Talbot effect. Boxes that are leaky, i.e. with penetrable walls, can be modelled by representing the walls as nonhermitian boundaries. The waves are superpositions of discrete eigenmodes with complex eigenvalues. Several different boundary conditions are explored, in which the Robin parameter—ratio of the mode derivatives and their values at the walls—may or may not depend on the eigenvalue. Nonhermitian models, which ignore the waves leaking outside the box, or represent them in simplified form, are approximations. For one physical model, the evolving wave in the full space can be calculated exactly, indicating that the nonhermitian model for the wave inside is highly accurate. Leaky boxes can be useful pedagogically: as introductory examples of nonhermiticity and biorthogonality (left and right eigenvectors), and as a rich source of postgraduate or advanced undergraduate student projects, exploring many variants.
Temperature-activated dielectric relaxation in lead-free halide perovskite single crystals
Authors: Paul Rajashik , Tailor Naveen Kumar , Mahaptra Apurba , Yadav Pankaj , Satapathi Soumitra
Published: July 2022

Lead-free metal-halide perovskites have recently appeared as a promising candidate in optoelectronics and photovoltaics because of their non-toxicity, stability, and unique photophysical properties. Much scientific research has been done on optoelectronic characteristics and photovoltaic applications of lead-free perovskites, but the dielectric characteristics and insight into the relaxation phenomenon remain elusive. Here, we study the dielectric relaxation and conduction mechanism in the single crystalline (SC) A3Bi2X9 (A = MA+/FA+) perovskite using temperature-dependent electrochemical impedance spectroscopy in correlation with the modulus spectroscopy. With increasing temperature, the peak of −Z″(ω) shifts toward a high-frequency regime which specifies the thermally dependent relaxation mechanism in both crystals. The activation energy was estimated as 381 meV for MA3Bi2I9 (MBI) crystal and 410 meV for the FA3Bi2I9 (FBI) crystal suggesting hopping of mobile ions between lattice sites. The connected orientational polarization with the thermal motion of molecules leads to the enhancement in the dielectric constant (ϵ′) with temperature. The ϵ″(ω) in these crystals shows the significant ionic conductivity with a typical 1/fγ
type characteristics (in the low-frequency regime) where γ is found to be in the range of 0.93–1.0 for MBI crystal and 0.88–0.98 for FBI crystal. The correlated imaginary part of impedance (−Z″) and modulus (M″) demonstrate the temperature-activated delocalized relaxation (non-Debye toward the Debye type) in these crystals. Stevels model suggests that the contribution of traps reduces with temperature rise and therefore conductivity enhances. Our study provides a comprehensive analysis and in-depth knowledge about the dielectric and conductivity relaxation mechanism in these lead-free perovskite SCs, which will help to implement efficient energy storage devices using these materials.
Current-driven periodic domain walls injection in a ferromagnetic nanostrip with a modified perpendicular magnetic anisotropy region
Authors: Zhou Xiuping , Ren Hanyu , Jiang Congying , Wang Fan , He Xinyan , Chen Zhenzhen , Qiu Yang , Zhu Mingmin , Yu Guoliang , Zhou Haomiao
Published: July 2022

Effective control of domain wall (DW) injection and motion in a ferromagnetic nanostrip is of great significance for the development of DW-based spintronic devices. In this work, we exploit the properties of 90° magnetization walls induced by a modified perpendicular magnetic anisotropy (PMA) between the out-of-plane and in-plane magnetized regions of Pt/Co, with spin-transfer torque (STT) being used to control the injection of DWs into a ferromagnetic nanostrip. We demonstrate that this STT stimulus combined with the modified PMA enables the continuous and synchronous injection of a series of head-to-head and tail-to-tail transverse in-plane DWs. Furthermore, micromagnetic simulation results show that the presence of a 90° magnetized transition region is a prerequisite for magnetic DW injection, and that the generation frequency can be controlled reversibly from the MHz to the multi-GHz range. Our findings demonstrate the feasibility of a highly tunable and direct-current-controlled transverse in-plane DW signal source, which could pave the way toward compact and integrated DW circuits and oscillators.
Sn2Pd: a possible superconducting material with topological surface states
Authors: Sharma M M , Awana V P S
Published: July 2022

In this article, we report the detailed magneto transport measurements of topological semimetal candidate, Sn2Pd. Single crystal of Sn2Pd is synthesized through self-flux method. Phase purity and crystalline morphology are confirmed through powder x-ray diffraction pattern and field emission scanning electron microscopy image. Signatures of superconducting transition are seen in both transport and magneto transport measurements, which are further supported by the AC magnetization studies. Sn2Pd is found to show superconductivity onset at below 2.8 K, but not the zero resistivity down to 2 K. Although, isothermal magneto resistivity measurements below superconducting onset (2.8 K) clearly exhibited superconductor like behavior, but is not observed in heat capacity measurements, indicating the same to be of weak nature. Magneto transport measurements performed in normal state of Sn2Pd show the presence of weak antilocalization effect, which is confirmed by modelling of low field magneto-conductivity through Hikami Larkin Nagaoka formalism. Here, it is worth mentioning that the present article is the first report on magneto transport measurements of Sn2Pd, which show the same to be a topological material with weak superconducting phase below around 2.8 K.
Birkhoff normal form and twist coefficients of periodic orbits of billiards*
Authors: Jin Xin , Zhang Pengfei
Published: July 2022

In this paper we study the Birkhoff normal form around elliptic periodic points for a variety of dynamical billiards. We give an explicit construction of the Birkhoff transformation and obtain explicit formulas for the first two twist coefficients in terms of the geometric parameters of the billiard table. As an application, we obtain characterizations of the nonlinear stability and local analytic integrability of the billiards around the elliptic periodic points.
A novel method to measure the thermal diffusivity of transparent materials
Authors: Lee Wen-Tang , Lin Fong-Feng , Lou Yu-You
Published: July 2022

The refractive index of a liquid is known to depend strongly on the temperature gradient of liquids. When a laser beam passes through a transparent material going through thermal diffusion, the light projected onto a screen will be displaced in relation to the thermal diffusivity. A simple apparatus is used to measure the time evolution t of the laser beam displacement h and/vs. the position of the laser beam on the liquid container y whose liquid medium is going through thermal diffusion. Thermal diffusion dynamics can then be revealed. The thermal diffusivity of glycerol, ethanol, DI water, and NaCl aqueous solution has been measured. This simple procedure can demonstrate refractive index and thermal diffusivity in advanced high school physics courses.
Observation of libration and change in apparent diameter of the Moon with a pinhole camera
Authors: Matsutani Akihiro
Published: July 2022

We demonstrated that an optimally designed pinhole camera can be used as an astronomical tool to observe the libration and apparent diameter change of the Moon at night. The libration and apparent diameter change of the Moon were observed using a handmade pinhole camera with a diameter of 0.65 mm and a focal length of 400 mm. It was found that the lunar mare with its characteristic pattern can be observed using this pinhole camera with a resolution of 2.5 arcmin. It was also found that the apparent diameter change of the Moon of about 10% can be observed with this pinhole camera. The pinhole camera used in this experiment is very useful as a handmade scientific educational material for learning the principles of optics and the movement of the Moon.
A zero power current and frequency sensor for smart grid applications
Authors: Aragonez Omar , Jackson Nathan
Published: July 2022

Obtaining real time feedback on the amplitude and frequency of current flowing through power lines is of significant importance to smart grids. This paper investigates the use of a zero power multifunctional device (sensor and energy harvester) to solve this challenging problem. The passive device combines a piezoelectric cantilever with a hard magnet mass in order to couple the AC magnetic field from the power line to the device to generate an oscillating kinetic force at the frequency of the current. The proposed device is passive, but the transmission of the data requires the use of wireless sensor nodes, which requires power. The piezoelectric cantilever acts as both a passive sensor and a kinetic energy harvester to power the wireless sensor nodes. This study investigates the effects on both the sensor sensitivity and energy harvesting power density as a function of the type of wire (stranded vs solid wires), stiffness of the cantilever, and pull strength of the magnet for high current applications. The results demonstrate that stranded wires have a slight reduction in sensitivity from 1.12 V A−1 to 0.98 V A−1 for solid and stranded wire. The stiffness of the cantilever also affects the sensitivity and energy harvesting performance, where stiffer beams resulted in high power density and sensitivity. Increasing the magnet thickness and pull strength resulted in increased power density and bandwidth but it also effects the optimal spatial location of the magnet in relation to the wire. The device was also validated as a frequency sensor with a resolution of <1 Hz, and could be further optimized in the future. The results of this study validate the potential use of the device as a multifunctional sensor/energy harvester for smart grid applications.
An optical transition-edge sensor with high energy resolution
Authors: Hattori Kaori , Konno Toshio , Miura Yoshitaka , Takasu Sachiko , Fukuda Daiji
Published: July 2022

Optical transition-edge sensors (TESs) have shown an energy resolution for resolving the number of incident photons at the telecommunication wavelength. However, a higher energy resolution is required for biological imaging and microscopic spectroscopy. In this study, we tested an Au/Ti (10/20 nm) bilayer TES that showed a high energy resolution. The high energy resolution was achieved by lowering the critical temperature

T

c

to 115 mK, and the resultant energy resolution was 67 meV full width at half maximum (FWHM) at 0.8 eV. When

T

c

was reduced to 115 mK, the theoretical resolution would scale up to 30 meV FWHM, considering that the typical energy resolution of optical TESs was 150 meV and

T

c

was 300 mK. To investigate the difference between the theoretical expectation (30 meV) and the measured value (67 meV), we measured the complex impedance and current noise of the TES. We found excess Johnson noise in the TES; the excess Johnson noise term M was 1.5 at a bias point where the resistance was 10% of the normal resistance. For reference, the above mentioned TES was compared with a TES showing typical energy resolution (156 meV FWHM). We also discussed factors that improved or inhibited the energy resolution.
Dynamics of charged aerosols relevant to transmission of airborne infections
Authors: Karimov A R , Stenflo L , Yu M Y
Published: July 2022

A simple model including the effects of initial velocity, air drag, gravity, and electrostatics on the dynamics of airborne droplets emitted from humans is presented. It is found that relatively large droplets can also travel far if their charge and/or the atmospheric electric field is sufficiently large.
Non-relativistic scattering by a shield barrier and by an elliptical aperture
Authors: Schmidt Alexandre G M , de Jesus Anderson L
Published: July 2022

We study the non-relativistic quantum mechanical scattering of a plane wave by a shield barrier and an elliptical aperture modeled as Dirac delta functions running along a coordinate surface of the sphero-conal coordinate system. The scattering problem is formulated via Lippmann-Schwinger (LS) equation in the position representation. In order to solve the LS equation, we first calculate the free Green's function of the problem and obtain its bilinear expansion in terms of the eigenfunctions of the scalar Helmholtz equation—which are products of spherical Bessel (or first kind Hankel) functions and Lamé polynomials. Such bilinear expansion allows us to obtain an integral equation with a separable kernel and solve the scattering problem. Then, we calculate the wavefunctions in the internal and external domains and the scattering amplitudes.
The QCD phase transition behind a PBH origin of LIGO/Virgo events?
Authors: Iguaz Joaquim , Serpico Pasquale D. , Franco-Abellán Guillermo
Published: July 2022

The best-motivated scenario for a sizable primordial black hole (PBH) contribution to the LIGO/Virgo binary black hole mergers invokes the QCD phase transition, which naturally enhances the probability to form PBH with masses of stellar scale. We reconsider the expected mass function associated not only to the QCD phase transition proper, but also the following particle antiparticle annihilation processes, and analyse the constraints on this scenario from a number of observations: the specific pattern in cosmic microwave background (CMB) anisotropies induced by accretion onto PBHs, CMB spectral distortions, gravitational wave searches, and direct counts of supermassive black holes (SMBHs) at high redshift. We find that the scenario is not viable, unless an ad hoc mass evolution for the PBH mass function and a cutoff in power-spectrum very close to the QCD scale are introduced by hand. Despite these negative results, we note that a future detection of coalescing binaries involving sub-solar PBHs has the potential to check the cosmological origin of SMBHs at thee±annihilation epoch, if indeed the PBH mass function is shaped by the changes to the equation of state driven by the thermal history of the universe.
Optical Observations of the Nearby Type Ia Supernova 2021hpr
Authors: Zhang Yu , Zhang Tianmeng , Danzengluobu  , Li Zhitong , Zhao Pinsong , Zhang Bingqing , Du Lin , Zhu Yinan , Wu Hong
Published: July 2022

We present the optical photometric and spectroscopic observations of the nearby Type Ia supernova (SN) 2021hpr. The observations covered the phase of −14.37 to +63.68 days relative to its maximum luminosity in the B band. The evolution of multiband light/color curves of SN 2021hpr is similar to that of normal Type Ia supernovae (SNe Ia) with the exception of some phases, especially a plateau phase that appeared in the V − R color curve before peak luminosity, which resembles that of SN 2017cbv. The first spectrum we observed at t ∼ −14.4 days shows a higher velocity for the Si ii
λ6355 feature (∼21,000 km s−1) than that of other normal velocity (NV) SNe Ia at the same phase. Based on the Si ii
λ6355 velocity of ∼12,420 km s−1 around maximum light, we deduce that SN 2021hpr is a transitional object between high velocity (HV) and NV SNe Ia. Meanwhile, the Si ii
λ6355 feature shows a high velocity gradient (HVG) of about 800 km s−1 day−1 from roughly −14.37 to −4.31 days relative to the B-band maximum, which indicates that SN 2021hpr can also be classified as an HVG SN Ia. Despite SN 2021hpr having a higher velocity for the Si ii
λ6355 and Ca ii near-IR (NIR) triplet features in its spectra, its evolution is similar to that of SN 2011fe. Including SN 2021hpr, there have been six supernovae observed in the host galaxy NGC 3147; the supernovae explosion rate in the last 50 yr is slightly higher for SNe Ia, while for SNe Ibc and SNe II it is lower than expected rate from the radio data. Inspecting the spectra, we find that SN 2021hpr has a metal-rich (12 + log(O/H) ≈ 8.648) circumstellar environment, where HV SNe tend to reside. Based on the decline rate of SN 2021hpr in the B band, we determine the distance modulus of the host galaxy NGC 3147 using the Phillips relation to be 33.46 ± 0.21 mag, which is close to that found by previous works.
Parametrisation of target heat flux distribution and study of transport parameters for boundary modelling in W7-X
Authors: Bold David , Reimold Felix , Niemann Holger , Gao Yu , Jakubowski Marcin , Killer Carsten , Winters Victoria R.
Published: July 2022

Modelling the scrape-off layer (SOL) of a stellarator is challenging due to the complex magnetic 3D geometry. The here presented study analyses simulations of the SOL of the stellarator Wendelstein 7-X using the EMC3-EIRENE code for the magnetic standard configuration. Comparing with experimental observations, the transport model is validated. Based on the experimentally observed strike line width, the anomalous transport coefficients, used as input to the code are determined to around 0.2 m2 s−1. This is however in disagreement with upstream measurements, where such small cross-field transport leads to temperatures higher than measured experimentally.
Analysis of discrepancies between D1S and R2S results of 2016 DD JET Campaign
Authors: Alguacil J. , Catalan J.P. , Sauvan P. , Villari R. , Batistoni P. , Sanz J.
Published: July 2022

In the frame of the WPJET3-DT Technology project within the EUROfusion Consortium program, neutronics experiments are being carried out in preparation for the current deuterium–tritium campaign on JET (DTE2). The experiments are conducted to validate the neutronics codes and tools used in ITER, thus reducing the related uncertainties and the associated risks in the machine operation. Recently, the shutdown dose rate (SDR) results of the 2016 DD campaign have been analyzed using the D1S and R2S computational methodologies showing relevant differences between the results provided by both methods. The greatest discrepancies, found in the SDR calculated in the second octant at 6 h after shutdown, are a factor 2 of difference in the total decay photon flux and a different peak location close to 0.511 MeV. This article presents a detailed analysis of the D1S and R2S simulations performed to find the causes of these discrepancies. The conclusions of the analysis determine that the use of the typical neutron and gamma energy structures used in common R2S simulations can tend to a photon flux significant overestimation or a shift in the output spectrum, respectively. In addition to alerting about this important problem in R2S calculations, this article also proposes a solution to mitigate each effect that can be implemented in R2S codes. The application of the proposed solutions significantly reduces the differences between the photon spectrum calculated with D1S and R2S methods.
Survival probability of random walks and Lévy flights with stochastic resetting
Authors: Godrèche Claude , Luck Jean-Marc
Published: July 2022

We perform a thorough analysis of the survival probability of symmetric random walks with stochastic resetting, defined as the probability for the walker not to cross the origin up to time n. For continuous symmetric distributions of step lengths with either finite (random walks) or infinite variance (Lévy flights), this probability can be expressed in terms of the survival probability of the walk without resetting, given by Sparre Andersen theory. It is therefore universal, i.e. independent of the step length distribution. We analyze this survival probability at depth, deriving both exact results at finite times and asymptotic late-time results. We also investigate the case where the step length distribution is symmetric but not continuous, focusing our attention onto arithmetic distributions generating random walks on the lattice of integers. We investigate in detail the example of the simple Polya walk and propose an algebraic approach for lattice walks with a larger range.
Analysis and optimization of Dual secondary fuel injector for Thrust vector control
Authors: Sharma Kuldeep , Manohar P M S S , Mishra Ankit Kumar
Published: July 2022

The motive of this analysis is to compare the performance parameters of a single secondary fuel injector and performance of Dual Secondary fuel injector system for Thrust Vector Control (SITVC) in a supersonic nozzle for different distances between the two ports. With the help of Computational Fluid Dynamics (CFD) the performance characteristics of SITVC has been analyzed. Experimental and numerical investigations have been done with various circumstances to examine the performance augmentations of the 2-D nozzle.
Computer-Aided Simulation of Automotive Air Conditioning System
Authors: Suriyakumar J. , Anbazhagan G.
Published: July 2022

Traditionally, automotive air conditioning systems have been developed by selecting the appropriate components to meet the heat load estimates of a vehicle. The practical approach of component selection and testing to get desired output is expensive and time-consuming. Hence, computer-aided simulation plays a vital role to achieve optimal results without loss of money and time. For this purpose, this research work develops and implements a simulation methodology that accurately estimates the performance of the air conditioning system. An integrated model comprising of sub-models for heat exchangers, compressors, and expansion valves has been developed. The simulation model involves assigning each component a functional and a performance model that forms an analysis cycle.
Analysis on Fiber Reinforced Epoxy Concrete Composite for Industrial Flooring – A Review
Authors: Prabakaran E. , Vasanth Kumar D , Jaganathan A. , Ashok Kumar P , Veeerapathran M.
Published: July 2022

Fiber composites are the having an good scope in construction industry as they are light in weight, durable, economic, and resistant to temperatures. Many researchers concentrate on the composites for the industrial flooring with the fibers. The main objective of this paper is to review the fiber reinforced epoxy for industrial flooring. Epoxy can be used as flooring elements in industries as they deliver good performance. Since, natural and synthetic fibres can be used with filler matrices, which are very much cheaper than the conventional steel fibres reinforced composite concrete flooring and other type of composites here fibre is considered for reinforcing with epoxy or polymer concrete filler matrix. Fibre-polymer and fibre-concrete composite properties has been reviewed for testing procedure for flexural test, bending test, tensile test and based on the results, it is clear that the fibre-polymer concrete composite, which has good mechanical properties and performance than the mentioned composites, can be made for industrial flooring
Cylinder deactivation technique in multi-cylinder engines for fuel consumption reduction
Authors: Vinod kumar MN , Thamotharan C. , Naveenchandran P. , Raja E.
Published: July 2022

Cylinder deactivation is well-known in spark-ignited (SI) engines and compression-ignited (CI) engines. The major reason why the efficiency of these engines is decreased at part load is due to flow restriction in the intake system caused by partially closing throttle valves, which causes increased pumping losses. In order to resolve this issue, the cylinder deactivation system can be implemented in SI engines with four cylinders by developing a suitable control system. Half of the engine's cylinders had their fuel injectors and valve trains turned off, enabling cylinder deactivation (CDA). Fuel consumption was reduced by reducing engine impelling work and decreasing heat transmission to the walls of the cylinder. CDA techniques are tested for their impact on in-cylinder pressure and pumping loss. This work reveals that all of these cylinder deactivation solutions minimize pumping losses and fuel consumption thereby enhancing the engine's thermal efficiency. These findings suggest that closing both intake and exhaust valves is the most effective way of triggering CDA, and lowering BSFC (Brake-specific fuel consumption).
Neural fuzzy network configurator for calculating a residual life of production equipment
Authors: Semenov M E , Ilina S A , Rutskov A L
Published: July 2022

In this paper, an intelligent fault diagnosis scheme based on big data analysis method and adaptive neuro-fuzzy inference system (ANFIS) is proposed. An experimental study is given on the example of an electric drive of a stirrer of a hydrogenator reactor to illustrate the effectiveness of the proposed method and algorithmic solutions. Numerical experiments demonstrated the possibility of scaling proposed methodology for a wide class of similar process objects with the achievement of accuracy not less than 96.5%. The residual life calculation based on the ANFIS model have been carried out.
Construction of digital terrain models for testing active-pulse television measuring systems
Authors: Zakhlebin A , Movchan A , Kuryachiy M
Published: July 2022

The paper considers algorithm for creating a dense cloud of points and an orthomosaic plan of the terrain based on images obtained from a television camera of an unmanned aircraft. Geographic referencing of models is carried out using control points, the exact coordinates of which are determined by the instrumental method in the required coordinate system. The analysis of the number of identification marks involved influence in photogrammetric processing on the final model accuracy is carried out. The possibility of using the obtained models for testing active-pulse television measuring systems is considered.
Influence of the shield on the ultrashort pulse decomposition in a modal filter realized on a double-sided printed circuit board
Authors: Samoylichenko M A , Gazizov T R
Published: July 2022

A modal filter (MF) with four reference conductors (at the edges of the MF on the outer layers) and with the removal of two diagonal reference conductors is simulated. Using the example of two MFs, the influence of connecting the reference conductors with the shield is evaluated. It is shown that connecting the reference conductors with each other with a shield can eliminate their influence, and the shield can be used as reference conductors. The influence of the shield on the decomposition of the ultrashort pulse in two MF is estimated. The increase in the distance from the conductors to the shield is investigated. It is shown that with increasing the distance, the difference in per-unit-length delays becomes smaller for two MFs. In addition, the amplitude of the first pulse decreases and of the second pulse increases. A greater influence of the shield in the MF without two conductors is revealed.
Continuous wave THz imaging of multi-walled carbon nanotubes polymer composites
Authors: Berdyugin A I , Badin A V , Kuleshov G E , Trofimow E A , Smygalina P P , Dorozhkin K V , Schematilo T N , Gursky R P
Published: July 2022

In this paper, the problem of creating homogeneous composites with on carbon nanotubes is described. To control the quality of the manufactured composites, a system of terahertz visualization of material inhomogeneity using a continuous radiation source is used. An increase in the homogeneity of the composite based on multi-walled carbon nanotubes with an increase in the time of ultrasonic processing during polymerization is noted. The advantages of THz imaging in comparison with optical microscopy are shown.
Research of light diffraction on multilayer PPM-LC diffraction structures under conditions of external electrical influence
Authors: Rastrigin D S , Ivanchenko V G , Dolgirev V O , Sharangovich S N
Published: July 2022

The paper presents a theoretical model of light diffraction on multilayer PPM-LC diffraction structures. A numerical calculation of the diffraction characteristics of four-layer PPM-LC diffraction structures under the influence of external electrical action is also given. The possibility of controlling the type of selective response under the influence of an external electric field on each layer of the structure is shown.
Numerical modeling of discharge characteristics of a planar magnetron with injection of electrons from auxiliary discharge
Authors: Zolotukhin D B
Published: July 2022

We present here a numerical model of a planar magnetron with electron injection from the plasma of an auxiliary discharge with the hollow cathode. The model is based on solving a system of stationary equations using the method of successive approximations. The model takes into account the effects of the current of the injected electrons, the operating gas pressure, the magnetic field induction, the flow of the target material into the plasma, and the change in the plasma mass-to-charge composition due to cathode sputtering by ion bombardment. Typical volt-ampere characteristics of a magnetron discharge with electron injection, as well as the mass-to-charge composition of the created gas-metal plasma, are calculated.
Development of the NPA based diagnostic complex in ITER
Authors: Afanasyev V.I. , Chernyshev F.V. , Kozlovsky S.S. , Melnik A.D. , Marinin G.V. , Mironov M.I. , Navolotsky A.S. , Nesenevich V.G. , Petrov M.P. , Petrov S.Ya. , Yatsenko A.V. , Chugunov I.N. , Doinikov D.N. , Iliasova M.V. , Gin D.B. , Khilkevitch E.M. , Polunovsky I.A. , Shevelev A.E. , Artemev K.K. , Krasilnikov V.A. , Kormilitsyn T.M. , Kovalev A.O. , Mokeev A.N. , Turnyanskiy M.R.
Published: July 2022

The NPA based diagnostic complex in ITER consists of four diagnostics: the neutral particle analyzers, the diamond neutral particle spectrometer, the gamma-ray spectrometer, and the neutron spectrometer. The diagnostics are located in equatorial port #11 and share the same vacuum channel. The present paper considers the physical basis of the diagnostic complex and its measurement capabilities in ITER. In addition, the design of the complex and the engineering solutions implemented to meet the ITER requirements are described.
Practical considerations in developing nuclear detectors for tokamak harsh environments
Authors: Angelone M. , Raj P.
Published: July 2022

Fusion tokamaks (FT) and hybrid fusion-fission reactors (HFFR) present harsh working conditions characterized by intense neutron and gamma fluxes (>1012 cm−2 s−1), high working temperatures (up to 600 °C) and corrosive environment. The breeding blanket region (BB) of these plants are resulting very hostile to the detectors used to monitor/measure fundamental nuclear parameters such as neutron/gamma fluxes and energy spectra, and tritium production. Presently no detectors are ready for being hosted in the harsh environment of the BB and R&D activity is needed to develop and test the candidate detectors. Some important lessons can be learned from past activities carried out in the EU and devoted to studying and realizing nuclear detector prototypes for the European Test Blanket Modules (TBM) of ITER. Amongst the other, these studies pointed out the need for intense neutron fields and calibration facilities closely reproducing the expected working environments to be used for reliable testing and calibration of the prototypes.

Accurate simulation by Monte Carlo technique of the proposed detectors allows to mimic and foresee the response and performances of the detectors pointing out several fundamental and critical aspects on the physical response of the detector so helping in understanding the detectors response. This can help in selecting the best performing detector. The selection is based upon a multi-step procedure.

The lesson learned for ITER-TBM can be helpful to study and develop nuclear detectors to be used in HFFR reactors and in next fusion machines like DEMO this because, despite the difference, the ITER-TBMs and the BB of fusion devices and HFFR reactors experience a number of similarities in terms of radiation level, temperature and nuclear quantities to be measured.

In this paper, after discussing the requirements to be fulfilled by the nuclear detectors that must operate in the harsh environments we will discuss an example of detector development by considering the case of a self-power neutron detector (SPND) with chromium emitter studied and developed for ITER-TBM. The detailed Monte Carlo analysis is also reported and the many issues not yet solved are highlighted and the possible follow up to HFFR instrumentation discussed.
A low power clock generator 400–1800 MHz for ADPLL
Authors: Atkin E. , Ivanov P. , Normanov D.
Published: July 2022

This paper describes a low-power all-digital clock generator (ADCG) designed for reading and processing signals from detectors of large physical experiments. The clock generator operates with a reference clock frequency of 10 to 50 MHz and generates an output signal ranging from 400 to 1800 MHz in 10 MHz steps. The clock generator has been approved in 28 nm CMOS technology of TSMC. The power consumption and chip area of the block are 1.5 mW and 80 × 80 μm2 correspondingly. A wide range of reference and output frequencies makes this block versatile in application.
Proton Sound Detector for beam range/dose measurement in FLASH hadron therapy
Authors: Vallicelli E.A. , Baschirotto A. , De Matteis M.
Published: July 2022

Proton Sound Detectors (ProSDs) sense (at low latency, <1 ms) the thermoacoustic signal generated by the fast energy deposition at the Bragg peak of a proton beam penetrating an energy absorber. ProSDs are especially promising for experimental monitoring of high pulse rate (FLASH) hadron therapy treatments working in-sync with the beam. This paper presents a mixed signal detector, capable of sensing and processing high rate (1k beam shots/sec) ionacoustic signals with low latency (<1 ms). The system was validated by measuring the dose deposition of a 20 MeV proton beam in water, achieving 3.43% precision (±2.75 GyRMS) after 50 ms acquisition (77.56 Gy total dose deposition).
Ion temperature spectroscopic measurements in high rotation discharges by means of X-ray diagnostic at JET
Authors: Kozioł Karol , Brosławski Andrzej , Patel Ashwin , Weisen Henri , Rzadkiewicz Jacek
Published: July 2022

Measurement of the X-ray spectra of the He-like Ni ions (Ni26+) and their dielectronic satellites (Ni25+, Ni24+, and Ni23+) plays a crucial role in determination of electronic and ion temperature of plasma in the JET device. Because n ⩾ 3 satellites of Ni25+ overlap with resonance line of Ni26+, it is important to reconstruct the structure of these satellites reliably. It is especially important in the cases when plasma rotation is high which may result in an additional broadening of the resonance line. This work is an attempt to identify possible causes of the additional broadening of the resonance line due to the effect of overlapping the dielectronic satellites with the resonance line of Ni26+ and the effect of toroidal plasma rotation shear.
A programmable readout system for 3He/BF3 neutron detectors
Authors: Venturini Y. , Abba A. , Garosi P. , Paoli N. , Tintori C. , Venaruzzo M.
Published: July 2022

CAEN SpA has developed a 19″ rack-mount solution for the readout of 3He/BF3 tubes. It is a scalable system allowing the user to put together few to hundreds neutron detectors. It is composed of a CAEN R803x high voltage board, CAEN R1443 preamplifier specifically designed to work at best with 3He/BF3 tubes and CAEN R5560 14-bit 125 MS/s open FPGA digitizer. Thanks to its firmware programmability, this readout system can perform specific filtering to achieve the best charge, timing and position measurements. CAEN provides a DAQ software to remotely manage the system and acquire waveforms, energy, ToF spectra and perform position reconstruction. Moreover, the R5560 offers the possibility to use SCI-Compiler, a block-diagram-based software which allows to easily implement custom pulse processing algorithms in the board FPGA.