bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using maize to evaluate the Mohammadi–Khataar (M–K) model as a salinity weighting function (
Authors: Asadi Zahra , Mohammadi Mohammad Hossein , Shorafa Mehdi , Farahbakhsh Mohsen 
Published: May 2022

Context Soil water availability, as characterised by the integral water capacity, uses weighting functions based on models not yet evaluated using plants, especially in the context of saline soils. Without plant evaluation such weighting functions remain theoretical at best. Aims We aimed to use maize plants to evaluate Mohammadi and Khataar’s (2018) conceptual model for a salinity weighting function, against those used in Hydrus 1D. Methods We conducted glasshouse experiments with large columns of two sandy loams planted with maize irrigated using different salinities, and repeated without plants. Soil matric suction ranged between saturation and 100 cm, and we measured or predicted plant height, transpiration, evaporation, drainage, storage, and solute concentration over time. The soil water retention curve was measured and the weighted mean hydraulic conductivity was obtained using the van Genuchten model. Key results We found a correlation between our salinity weighting function and the relative transpiration rate of maize (grown in two different soils using irrigation water of three different salinities), particularly in the first few days of growth but not thereafter; errors were related to uncertainties in predicting drainage, salt concentration, and soil water storage in planted columns. Conclusions The deviation of transpiration rate from that predicted by our salinity weighting function at higher salinities may relate to the linear nature of the Maas–Hoffman salinity weighting function plus heterogeneity of soil water and solute distributions. Implications Improving the estimates of drainage and soil water storage in future would make our physical model more useful in larger scale hydrological predictions.
Transsynaptic cerebellin 4–neogenin 1 signaling mediates LTP in the mouse dentate gyrus
Authors: Liakath-Ali Kif , Polepalli Jai S. , Lee Sung-Jin , Cloutier Jean-Francois , Südhof Thomas C. 
Published: May 2022

SignificanceSynapses are controlled by transsynaptic adhesion complexes that mediate bidirectional signaling between pre- and postsynaptic compartments. Long-term potentiation (LTP) of synaptic transmission is thought to enable synaptic modifications during memory formation, but the signaling mechanisms involved remain poorly understood. We show that binding of cerebellin-4 (Cbln4), a secreted ligand of presynaptic neurexin adhesion molecules, to neogenin-1, a postsynaptic surface protein known as a developmental netrin receptor, is essential for normal LTP at entorhinal cortex→dentate gyrus synapses in mice. Cbln4 and neogenin-1 are dispensable for basal synaptic transmission and not involved in establishing synaptic connections as such. Our data identify a netrin receptor as a postsynaptic organizer of synaptic plasticity that collaborates specifically with the presynaptic neurexin–ligand Cbln4.
Lab courses for prospective physics teachers: what could we learn from the first COVID-19 lockdown?
Authors: Jelicic K , Geyer M-A , Ivanjek L , Klein P , Küchemann S , Dahlkemper M N , Susac A 
Published: May 2022

Abstract
At the universities of Dresden, Vienna, and Zagreb, a laboratory course for prospective physics teachers was transferred to an online environment because of the lockdown in March 2020 due to the COVID-19 pandemic. The aim of this paper is to present and compare students’ and instructors’ considerations about the experiences with this laboratory course at these three universities and to formulate guidelines for organizing lab courses for prospective physics teachers. The research was conducted in three steps: first, interviews were conducted with prospective physics teachers (N = 10); second, an online questionnaire was administered to course participants (N = 99); and third, lab course instructors completed an online questionnaire (N = 8). The results show that an increase in creativity and confidence was expressed when conducting home experiments. Students who received support and guidance benefited more from the online lab course, but some students also experienced a greater time commitment. On a positive note, all participants thought outside-the-box during this lab experience and found solutions that led to new ways of conducting labs. Our study suggests that in future online or regular lab courses, students should have the chance to make decisions about experiments and be creative, with an emphasis on peer discussions and support from instructors.
Evaporation of confined droplet between parallel chips with varying gap at room temperature
Authors: Dubey Vikas 
Published: May 2022

Abstract
A theoretical study and experimental validation of the evaporation of a droplet confined between two parallel square chips with a free-standing top chip over a water meniscus is presented in this article. The analytical model describes the surface area of a negatively curved liquid–air interface, and the evaporation model was thus solved for this case. The dynamics of decreasing the gap between the two parallel chips show a linear dependency in time at room temperature. Two main regimes are observed in this case, the constant wetted area regime and the varying wetted area regime. The theoretical study was lastly validated through experiments.
Temperature and pressure effects on microchannels dimensions in hot embossing
Authors: Koochaksaraei Mohammad Mashhadban , Ahmadi Isa , Hajian Ramin , Mohammadi Mohammad Mostafa 
Published: May 2022

Abstract
Hot embossing is a microfabrication technique for making microchannels and microfluidic devices. Temperature and pressure along with the material thermos-mechanical properties are the key parameters in controlling the shape of embossed channels. In this paper, experimental and numerical investigations of pressure and temperature effects on channel dimensions are presented. The material used as workpieces is poly methyl methacrylate (PMMA). The depth, upper width and lower width are the main dimensions of microchannel which are studied in this work. Experiments were performed at temperatures of 140 °C, 150 °C, 160 °C, 170 °C and 180 °C and pressures of 235, 295 and 340 kPa. Numerical and experimental results show a good agreement, i.e. 6.7% difference in dimensional length in the worst case and less than 0.3% in the best case. Based on width and depth values obtained via both experiments and simulations an optimum condition of temperature and pressure is presented in this paper for forming of microchannel on PMMA. Based on performed experiments, 150 °C with 295 kPa is found to be the nearest condition to the optimum point.
Magneto-optical absorption properties of topological insulator thin films
Authors: Hieu Nguyen V , Kubakaddi S S , Hieu Nguyen N , Phuc Huynh V 
Published: May 2022

Abstract
We theoretically study the magneto-optical absorption coefficients (MOACs) and the refractive index changes (RICs) due to both intra- and inter-band transitions in topological insulator (TI) thin films. The interplay between Zeeman energy and hybridization contribution leads to a transition between the normal insulator phase and the TI phase. The difference in the optical response in these two phases as well as at the phase transition point has been analyzed. The influence of the electron density, magnetic field, and temperature on the MOACs and RICs in both intra- and inter-band transitions is investigated. Our results show that the electron density affects directly the threshold energy. At a finite temperature, the thermal excitation causes the triggering of some new transitions which do not appear at T = 0 K. Evidence of the half-peak feature of the first inter-band transition is also found in TI thin films.
A closed local-orbital unified description of DFT and many-body effects
Authors: Flores Fernando , Soler-Polo Diego , Ortega José 
Published: May 2022

Abstract
Density functional theory (DFT) is usually formulated in terms of the electron density as a function of position n(r). Here we discuss an alternative formulation of DFT in terms of the orbital occupation numbers {n

α
} associated with a local-orbital orthonormal basis set {ϕ

α
}. First, we discuss how the building blocks of DFT, namely the Hohenberg–Kohn theorems, the Levy–Lieb approach and the Kohn–Sham method, can be adapted for a description in terms of {n

α
}. In particular, the total energy is now a function of {n

α
}, E[{n

α
}], and a Kohn–Sham-like Hamiltonian is derived introducing the effects of the electron–electron interactions via effective potentials,

{

V

α

eff

=
∂

E

e
e

[

{

n

β

}

]

/
∂

n

α

}

. In a second step we consider the Hartree and exchange energies and discuss how to describe them, in the spirit of a DFT approach, in terms of the orbital occupation numbers. In this contribution special attention is paid to the description of the (intra-atomic) correlation energy and corresponding correlation potentials {V
corr,α
}. For this purpose, a model system is analyzed in detail, whereby an atomic Hamiltonian interacts with the environment via a simplified model; the use of this model allows us to obtain the correlation energy and potentials (in terms of {n

α
}) for different cases corresponding to low, intermediate and high electron correlations.
Electrostatic treatment of charged interfaces in classical atomistic simulations
Authors: Tao Cong , Mutter Daniel , Urban Daniel F , Elsässer Christian 
Published: May 2022

Abstract
Artificial electrostatic potentials can be present in supercells constructed for atomistic simulations of surfaces and interfaces in ionic crystals. Treating the ions as point charges, we systematically derive an electrostatic formalism for model systems of increasing complexity, both neutral and charged, and with either open or periodic boundary conditions. This allows to correctly interpret results of classical atomistic simulations which are directly affected by the appearance of these potentials. We demonstrate our approach at the example of a strontium titanite supercell containing an asymmetric tilt grain boundary. The formation energies of charged oxygen vacancies and the relaxed interface structure are calculated based on an interatomic rigid-ion potential, and the results are analyzed in consideration of the electrostatic effects.
Cloud chamber kit for active learning in a first-year undergraduate nuclear science seminar class
Authors: White A E 
Published: May 2022

Abstract
This paper presents the design and reports on the use of a simple and inexpensive cloud chamber kit that is compatible with active learning, experiential learning, and project-based learning strategies. The kit was developed for use in a first-year undergraduate nuclear science seminar class at a university in the US. Diffusion cloud chambers are commonly used in classroom demonstrations to teach students about cosmic rays and ionizing radiation. A variety of clever and novel cloud chambers found in the literature were built and tested as part of this work and are all suitable for instructor-led classroom demonstrations. However, each has drawbacks that limit its use in hands-on classroom activities as part of active learning, experiential learning, and project-based learning in the classroom. The purpose of this work was to develop a cloud chamber ‘kit’ that can be built in less than 10 min by students during class and guarantees student success in observing background radiation. The cloud chamber kit was found to be highly sensitive to background radiation, and several different types of high-energy particles, including muons or anti-muons, electrons or positrons, photoelectrons, and alpha particles, were detected and identified using the kits at a rate of over 20 tracks per minute measured indoors at sea level at latitude 42.3601° N. The simplicity of the cloud chamber kit presented here makes it compatible with a variety of best practices for active learning in the classroom and requires little preparation time outside of class.
Development of an educational device, based on Arduino, to facilitate the understanding of light diffraction
Authors: Hachmi A , El Hadi M , Essaadaoui R , Mommadi O , Ouariach A , El Moussaouy A 
Published: May 2022

Abstract
The Arduino board and its communication with several sensors are becoming more and more popular in the physical science community. They offer inspiring possibilities for learning different physical concepts. In this article, we focused on creating a very practical educational system for experimenting with diffraction of laser light and graphically visualizing the distribution of light intensity in space, which is impossible to perform it with the devices available in the educational laboratories of physics. The main elements of this configuration are the Arduino UNO microcontroller board, the BH1750 sensor and the NEMA17 motor and its A4990 driver. The results’ graph is displayed in real time on the computer using the Data Streamer add-in. We see that the abbreviated curve corresponds well to the theory. In addition, feedback from the participants in the test activity of the device showed that they were satisfied with its operation and its contribution to the understanding of diffraction. Therefore, we believe that the device presented can play a very important role in the diffraction phenomenon learning because of its high precision and reliability in the measurements.
A mask-compatible, radiolucent, 8-channel head and neck receive array for MRI-guided radiotherapy treatments and pre-treatment simulation
Authors: Zijlema Stefan E , Breimer Wico , Gosselink Mark W J M , Bruijnen Tom , Arteaga de Castro Catalina S , Tijssen Rob H N , Lagendijk Jan J W , Philippens Marielle E P , van den Berg Cornelis A T 
Published: May 2022

Abstract
Immobilization masks are used to prevent patient movement during head and neck (H&N) radiotherapy. Motion restriction is beneficial both during treatment, as well as in the pre-treatment simulation phase, where magnetic resonance imaging (MRI) is often used for target definition. However, the shape and size of the immobilization masks hinder the use of regular, close-fitting MRI receive arrays. In this work, we developed a mask-compatible 8-channel H&N array that consists of a single-channel baseplate, on which the mask can be secured, and a flexible 7-channel anterior element that follows the shape of the mask. The latter uses high impedance coils to achieve its flexibility and radiolucency. A fully-functional prototype was manufactured, its radiolucency was characterized, and the gain in imaging performance with respect to current clinical setups was quantified. Dosimetry measurements showed an overall dose change of −0.3%. Small, local deviations were up to −2.7% but had no clinically significant impact on a full treatment plan, as gamma pass rates (3%/3 mm) only slightly reduced from 97.9% to 97.6% (clinical acceptance criterion: ≥95%). The proposed H&N array improved the imaging performance with respect to three clinical setups. The H&N array more than doubled (+123%) and tripled (+246%) the signal-to-noise ratio with respect to the clinical MRI-simulation and MR-linac setups, respectively. G-factors were also lower with the proposed H&N array. The improved imaging performance resulted in a clearly visible signal-to-noise ratio improvement of clinically used TSE and DWI acquisitions. In conclusion, the 8-channel H&N array improves the imaging performance of MRI-simulation and MR-linac acquisitions, while dosimetry suggests that no clinically significant dose changes are induced.
Developments on auxetic closed cell foam pressure vessel fabrications
Authors: Duncan O , Leslie G , Moyle S , Sawtell D , Allen T 
Published: May 2022

AbstractAuxetic foam can have higher indentation resistance, better protection under impact and higher vibration damping than conventional foam. Unlike auxetic open cell foam, with established, commercially viable options for manufacturing, methods for making auxetic closed cell foam are not established. We revisited pressure-vessel methods, proposed in 1996, for making auxetic closed cell foam. We processed low-density polyethylene foam for 6 h at 400–700 kPa and 100 °C, causing foams to shrink by a factor of two to five. The volumetric compression kinked cell walls, producing negative Poisson’s ratios as low as −0.2 and Young’s moduli from 0.2 to 1.2 MPa. Trends between applied volumetric compression and Poisson’s ratio agree with those for open cell foam—initially decreasing to negative values as volume reduced by a factor of two after processing, then plateauing or slightly increasing as volume decreased by a factor of two to five. Foams of different sizes and shapes (15–75 mm sides) processed in the same conditions (700 kPa, 6 h, 100 °C) shrank evenly in all three axes and had similar final volume ratios. We noticed a long settling period, of up to three months, where foams slowly shrank. Placing foam in a vacuum after processing reduced the settling period to within 24 h.
Scanning high-sensitive x-ray polarization microscopy
Authors: Marx-Glowna B , Grabiger B , Lötzsch R , Uschmann I , Schmitt A T , Schulze K S , Last A , Roth T , Antipov S , Schlenvoigt H-P , Sergueev I , Leupold O , Röhlsberger R , Paulus G G 
Published: May 2022

Abstract
We report on the realization of an extremely sensitive x-ray polarization microscope, allowing to detect tiniest polarization changes of 1 in 100 billion (10−11) with a μm-size focused beam. The extreme degree of polarization purity places the most stringent requirements on the orientation of the polarizer and analyzer crystals as well as the composition and the form fidelity of the lenses, which must not exhibit any birefringence. The results show that these requirements are currently only met by polymer lenses. Highly sensitive scanning x-ray polarization microscopy thus is established as a new method. It can provide new insights in a wide range of applications ranging from quantum electrodynamics and quantum optics to x-ray spectroscopy, materials research, and laser physics.
A new look at the C
0-formulation of the strong cosmic censorship conjecture
Authors: Iyer Aditya , Yosifov Alexander Y , Vedral Vlatko 
Published: May 2022

Abstract
We examine the C
0-formulation of the strong cosmic censorship conjecture (SCC) from a quantum complexity-theoretic perspective and argue that for generic black hole parameters as initial conditions for the Einstein equations, corresponding to the expected geometry of a hyperbolic black hole, the metric is C
0-extendable to a larger Lorentzian manifold across the Cauchy horizon. To demonstrate the pathologies associated with a hypothetical validity of the C
0 SCC, we prove it violates the ‘complexity = volume’ conjecture for a low-temperature hyperbolic AdS
d+1 black hole dual to a CFT living on a (d − 1)-dimensional hyperboloid H

d−1, where in order to preserve the gauge/gravity duality we impose a lower bound on the interior metric extendability of order the classical recurrence time.
Chaotic shadows of black holes: a short review
Authors: Wang Mingzhi , Chen Songbai , Jing Jiliang 
Published: May 2022

AbstractWe give a brief review on the formation and the calculation of black hole shadows. Firstly, we introduce the concept of a black hole shadow and the current works on a variety of black hole shadows. Secondly, we present the main methods of calculating photon sphere radius and shadow radius, and then explain how the photon sphere affects the boundary of black hole shadows. We review the analytical calculation for black hole shadows which have analytic expressions for shadow boundary due to the integrable photon motion system. And we introduce the fundamental photon orbits which can explain the patterns of black hole shadow shape. Finally, we review the numerical calculation of black hole shadows with the backward ray-tracing method and introduce some chaotic black hole shadows with self-similar fractal structures. Since the gravitational waves from the merger of binary black holes have been detected, we introduce a couple of shadows of binary black holes, which all have eyebrowlike shadows around the main shadows with the fractal structures. We discuss the invariant phase space structures of the photon motion system in black hole space-time, and explain the formation of black hole shadow is dominated by the invariant manifolds of certain Lyapunov orbits near the fixed points.
Self-phase modulation via similariton solutions of the perturbed NLSE Modulation instability and induced self-steepening
Authors: Abdel-Gawad H I 
Published: May 2022

Abstract
The perturbed nonlinear Schrodinger equation (PNLSE) describes the pulse propagation in optical fibers, which results from the interaction of the higher-order dispersion effect, self-steepening (SS) and self-phase modulation (SPM). The challenge between these aforementioned phenomena may lead to a dominant one among them. It is worth noticing that the study of modulation instability (MI) leads to the inspection of dominant phenomena (DPh). Indeed, the MI triggers when the coefficient of DPh exceeds a critical value and it may occur that the interaction leads to wave compression. The PNLSE is currently studied in the literature, mainly on finding traveling wave solutions. Here, we are concerned with analyzing the similarity solutions of the PNLSE. The exact solutions are obtained via introducing similarity transformations and by using the extended unified method. The solutions are evaluated numerically and they are shown graphically. It is observed that the intensity of the pulses exhibits self steepening which progresses to shock soliton in ultra-short time (or near t = 0). Also, it is found that the real part of the solution exhibits self-phase modulation in time. The study of (MI) determines the critical value for the coefficients of SS, SPM, or high dispersivity to occur.
A new concept for a gas proportional scintillation counter: the annular anode
Authors: Silva P.A.O.C. , Azevedo C.D.R. , Fernandes L.M.P. , dos Santos J.M.F. , Monteiro C.M.B. 
Published: May 2022

Abstract
A new design of a Gas Proportional Scintillation Counter (GPSC) for X-ray spectrometry is presented and a proof of concept is demonstrated. The proposed design is much simpler, having only one electrode, the anode. In addition, this electrode has an annular shape with its axis aligned with the photosensor axis. Since the scintillation region is limited to a small region near the anode, the solid angle subtended by the photocathode is similar relative to any position in the scintillation region and the amount of scintillation reaching the photosensor is independent from the position where the radiation interaction occurs. Standard GPSCs with uniform electric field design have the scintillation region parallel to the photosensor active area resulting in a dependence of the amount of light collected by the photosensor on the axial distance of the radiation interaction due to solid angle effects. These effects impose limitations on the size of the detector radiation window relative to the photosensor active area. Therefore, the annular anode allows to obtain a GPSC design with a larger radiation window relative to the photosensor area. A first GPSC prototype with a 10-cm diameter annular anode placed at a distance of 4.4 cm from the photosensor has an energy resolution of 14% for anode voltages of 8 kV and, according to simulations, it can reach 11% for anode voltages of 12 kV. This is worse than the values of 8–9% obtained with a standard GPSC which, on the other hand, have a window-to-photosensor diameter ratio lower than 0.8. Simulations have shown that the main factor degrading the energy resolution in this new design is the low number of photons impinging the photosensor due to the low solid angle subtended by the photosensor relative to the electroluminescence region of the detector. A compromise has to be made between the anode-to-photosensor diameter ratio as well as between the anode-to-photosensor distance and the energy resolution that can be achieved with the annular anode design.