bluuebunny/crossref_metadata_2025 huggingface dataset:
An efficient and spectral accurate numerical method for computing SDE driven by multivariate Gaussian variables
Authors: Xie Hongling
Published: July 2022

There are many previous studies on designing efficient and high-order numerical methods for stochastic differential equations (SDEs) driven by Gaussian random variables. They mostly focus on proposing numerical methods for SDEs with independent Gaussian random variables and rarely solving SDEs driven by dependent Gaussian random variables. In this paper, we propose a Galerkin spectral method for solving SDEs with dependent Gaussian random variables. Our main techniques are as follows: (1) We design a mapping transformation between multivariate Gaussian random variables and independent Gaussian random variables based on the covariance matrix of multivariate Gaussian random variables. (2) First, we assume the unknown function in the SDE has the generalized polynomial chaos expansion and convert it to be driven by independent Gaussian random variables by the mapping transformation; second, we implement the stochastic Galerkin spectral method for the SDE in the Gaussian measure space; and third, we obtain deterministic differential equations for the coefficients of the expansion. (3) We employ a spectral method solving the deterministic differential equations numerically. We apply the newly proposed numerical method to solve the one-dimensional and two-dimensional stochastic Poisson equations and one-dimensional and two-dimensional stochastic heat equations, respectively. All the presented stochastic equations are driven by two Gaussian random variables, and they are dependent and have multivariate normal distribution of their joint probability density.
Degrading methyl orange via prepare high dispersed TiO2/Al2O3 photocatalyst by combining anodizing and hydro-thermal technology
Authors: Liu Dong-Jie , Lei Jia-Heng , Wei Song , Jiang Bai-Ling , Xie Yun-Tao
Published: July 2022

To improve the photocatalytic activity of titanium oxide, nanometer titanium oxide powder was mixed with a phosphoric acid solution to form an electrolyte for preparing TiO2/Al2O3 coating on the surface of an aluminum alloy. Hydrothermal technology has been used to adjust the crystalline structure of nanometer titanium oxide. Scanning electron microscope was used to observe the micromorphology of anodic coating before and after treatment using hydrothermal technology. Results indicated that the photocatalyst had a porous structure. Energy dispersive spectrometry, x-ray diffraction, and x-ray photoelectron spectroscopy were used to confirm that titanium oxide was dispersed in the coating. The photocatalyst was used to degrade the methyl orange solution, and its absorbance before and after treatment by catalyst was tested by UV–vis spectroscopy. The results indicated that methyl orange could be degraded when the doping amount of titanium oxide is 8 g/l for 100 min.
Self-sustained oscillations in oxidation of methane over palladium: Experimental study and mathematical modeling
Authors: Lashina Elena A. , Vinokurov Zakhar S. , Saraev Andrey A. , Kaichev Vasily V.
Published: July 2022

An experimental study of the catalytic oxidation of methane over Pd foil in a flow reactor revealed that regular temporal oscillations in the reaction rate can arise at atmospheric pressure under methane-rich conditions. CO, CO2, H2, and H2O were detected as products. The oscillations of partial pressures of products and reactants in the gas phase were accompanied by oscillations of the catalyst temperature. According to an operando x-ray diffraction and mass-spectrometry study, the oscillations originate due to spontaneous oxidation and reduction of palladium; the high active catalyst surface is represented by metallic palladium, and the transition to the low-active state is accompanied by the formation of the PdO phase. In addition, it was detected that carbon dissolves in near-surface layers of palladium to form the PdCx phase. To describe the oscillations in the oxidation of methane, a 17-step reaction mechanism and a corresponding kinetic model were developed. The mechanism considers direct dissociative adsorption of methane and oxygen, pyrolytic activation of methane, oxidation and reduction of palladium, and direct formation and desorption of CO, CO2, H2, and H2O. Numerical solutions from the mathematical model of the continuously stirred-tank reactor qualitatively reproduce experimentally observed oscillatory dynamics. We have also developed a model, which considers the reversible diffusion of adsorbed oxygen and carbon atoms into the Pd bulk that allows us to explain the long induction period preceding the appearance of the oscillations. Mathematical modeling shows that the concentrations of dissolved oxygen and carbon atoms also oscillate under reaction conditions.
Bloch point dynamics in exchange-spring heterostructures
Authors: Charilaou Michalis
Published: July 2022

Magnetization textures that are stabilized by topological constraints, such as skyrmions and chiral bobbers, as well as the emergent electrodynamics associated with their motion, provide a promising avenue toward novel energy-efficient nanomagnetic devices. Here, it is shown that exchange-spring-type heterostructures, where soft ferromagnets with azimuthal symmetry are exchange-coupled to a ferromagnetic layer with perpendicular magnetic anisotropy, can be used for the creation and control of skyrmion tubes and Bloch points during magnetization reversal of the soft ferromagnet, where the rapid motion of the Bloch points induces an emergent electric field with a magnitude of the order of megavolts per meter. The exchange coupling to the hard ferromagnet restores the system to its original configuration, making the process fully reversible and repeatable, and the duration of the magnetization processes and the motion of the Bloch points can be tuned by adjusting the size of the ferromagnet. Based on these numerical predictions, it is proposed that exchange-spring heterostructures could be used to generate picosecond electromagnetic pulses.
Characterizing the flow and turbulence structure near the last closed flux surface in L-mode plasmas of ASDEX Upgrade
Authors: Nishizawa T. , Manz P. , Grenfell G. , Griener M. , Wendler D. , Brida D. , Kriete D. M. , Dux R. , Kobayashi T. , Sasaki M. ,   ASDEX Upgrade Team
Published: July 2022

Since high density operation is advantageous for building an efficient fusion reactor, understanding the density limit in tokamaks has been seen as one of the most important issues. This paper reports a series of measurements around the last-closed flux surface (LCFS) in L-mode plasmas by using a thermal helium beam diagnostic. Fluctuation analysis has been employed to characterize the poloidal flow and the turbulence structure. A reversal of the poloidal flow in the scrape-off layer and concomitant cooling of the outer divertor plasma are observed as the density is raised. While, in the confined region, the change in the density barely affects the poloidal flow, a higher density shifts the fluctuation power spectral densities toward lower frequencies and wave numbers. The eddy tilting of this region is consistent with what is expected from the magnetic shear effect. A radially coherent low frequency mode appears in the case of the highest density investigated in this study (n¯e/ne,GW = 0.51), and higher frequencies near the LCFS are modulated by this mode.
The N3/TiO2 interfacial structure is dependent on the pH conditions during sensitization
Authors: Farah Yusef R. , Krummel Amber T.
Published: July 2022

The electronic structure of the N3/TiO2 interface can directly influence the performance of a dye sensitized solar cell (DSSC). Therefore, it is crucial to understand the parameters that control the dye’s orientation on the semiconductor’s surface. A typical step in DSSC fabrication is to submerge the nanoparticulate semiconductor film in a solution containing the dye, the sensitizing solution. The pH of the N3 sensitizing solution determines the distribution of the N3 protonation states that exist in solution. Altering the pH of the sensitizing solution changes the N3 protonation states that exist in solution and, subsequently, the N3 protonation states that anchor to the TiO2 substrate. We utilize the surface specific technique of heterodyne detected vibrational sum frequency generation spectroscopy to determine the binding geometry of N3 on a TiO2 surface as a function of the sensitizing solution pH conditions. It is determined that significant reorientation of the dye occurs in pH ≤2.0 conditions due to the lack of N3-dye carboxylate anchoring groups participating in adsorption to the TiO2 substrate. Consequently, the change in molecular geometry is met with a change in the interfacial electronic structure that can hinder electron transfer in DSSC architectures.
Dental data challenge the ubiquitous presence of
Homo
in the Cradle of Humankind
Authors: Zanolli Clément , Davies Thomas W. , Joannes-Boyau Renaud , Beaudet Amélie , Bruxelles Laurent , de Beer Frikkie , Hoffman Jakobus , Hublin Jean-Jacques , Jakata Kudakwashe , Kgasi Lazarus , Kullmer Ottmar , Macchiarelli Roberto , Pan Lei , Schrenk Friedemann , Santos Frédéric , Stratford Dominic , Tawane Mirriam , Thackeray Francis , Xing Song , Zipfel Bernhard , Skinner Matthew M.
Published: July 2022

The origins of
Homo
, as well as the diversity and biogeographic distribution of early
Homo
species, remain critical outstanding issues in paleoanthropology. Debates about the recognition of early
Homo
, first appearance dates, and taxonomic diversity within
Homo
are particularly important for determining the role that southern African taxa may have played in the origins of the genus. The correct identification of
Homo
remains also has implications for reconstructing phylogenetic relationships between species of
Australopithecus
and
Paranthropus
, and the links between early
Homo
species and
Homo erectus
. We use microcomputed tomography and landmark-free deformation-based three-dimensional geometric morphometrics to extract taxonomically informative data from the internal structure of postcanine teeth attributed to Early Pleistocene
Homo
in the southern African hominin-bearing sites of Sterkfontein, Swartkrans, Drimolen, and Kromdraai B. Our results indicate that, from our sample of 23 specimens, only 4 are unambiguously attributed to
Homo
, 3 of them coming from Swartkrans member 1 (SK 27, SK 847, and SKX 21204) and 1 from Sterkfontein (Sts 9). Three other specimens from Sterkfontein (StW 80 and 81, SE 1508, and StW 669) approximate the
Homo
condition in terms of overall enamel–dentine junction shape, but retain
Australopithecus
-like dental traits, and their generic status remains unclear. The other specimens, including SK 15, present a dominant australopith dental signature. In light of these results, previous dietary and ecological interpretations can be reevaluated, showing that the geochemical signal of one tooth from Kromdraai (KB 5223) and two from Swartkrans (SK 96 and SKX 268) is consistent with that of australopiths.
Emergent evolutionary forces in spatial models of luminal growth and their application to the human gut microbiota
Authors: Ghosh Olivia M. , Good Benjamin H.
Published: July 2022

The genetic composition of the gut microbiota is constantly reshaped by ecological and evolutionary forces. These strain-level dynamics are challenging to understand because they depend on complex spatial growth processes that take place within a host. Here we introduce a population genetic framework to predict how stochastic evolutionary forces emerge from simple models of microbial growth in spatially extended environments like the intestinal lumen. Our framework shows how fluid flow and longitudinal variation in growth rate combine to shape the frequencies of genetic variants in simulated fecal samples, yielding analytical expressions for the effective generation times, selection coefficients, and rates of genetic drift. We find that over longer timescales, the emergent evolutionary dynamics can often be captured by well-mixed models that lack explicit spatial structure, even when there is substantial spatial variation in species-level composition. By applying these results to the human colon, we find that continuous fluid flow and simple forms of wall growth alone are unlikely to create sufficient bottlenecks to allow large fluctuations in mutant frequencies within a host. We also find that the effective generation times may be significantly shorter than expected from traditional average growth rate estimates. Our results provide a starting point for quantifying genetic turnover in spatially extended settings like the gut microbiota and may be relevant for other microbial ecosystems where unidirectional fluid flow plays an important role.
Comparing human and chimpanzee temporal lobe neuroanatomy reveals modifications to human language hubs beyond the frontotemporal arcuate fasciculus
Authors: Sierpowska Joanna , Bryant Katherine L. , Janssen Nikki , Blazquez Freches Guilherme , Römkens Manon , Mangnus Margot , Mars Rogier B. , Piai Vitoria
Published: July 2022

The biological foundation for the language-ready brain in the human lineage remains a debated subject. In humans, the arcuate fasciculus (AF) white matter and the posterior portions of the middle temporal gyrus are crucial for language. Compared with other primates, the human AF has been shown to dramatically extend into the posterior temporal lobe, which forms the basis of a number of models of the structural connectivity basis of language. Recent advances in both language research and comparative neuroimaging invite a reassessment of the anatomical differences in language streams between humans and our closest relatives. Here, we show that posterior temporal connectivity via the AF in humans compared with chimpanzees is expanded in terms of its connectivity not just to the ventral frontal cortex but also to the parietal cortex. At the same time, posterior temporal regions connect more strongly to the ventral white matter in chimpanzees as opposed to humans. This pattern is present in both brain hemispheres. Additionally, we show that the anterior temporal lobe harbors a combination of connections present in both species through the inferior fronto-occipital fascicle and human-unique expansions through the uncinate and middle and inferior longitudinal fascicles. These findings elucidate structural changes that are unique to humans and may underlie the anatomical foundations for full-fledged language capacity.
Flint glass bottles cause white wine aroma identity degradation
Authors: Carlin Silvia , Mattivi Fulvio , Durantini Victoria , Dalledonne Stefano , Arapitsas Panagiotis
Published: July 2022

Due to marketing recommendations, white wines are often bottled in flint glass to improve aesthetics and showcase wine color. Although this practice is known to cause a wine fault, the influence of light on the fruity and flowery aromatic profile of wine is unknown. The aim of this study was to investigate the changes to the white wine volatilome under typical supermarket shelf conditions, using 1,052 bottles of 24 white wines. After only 7 d of shelf life in flint glass bottles, a dramatic loss in terpenes (10 to 30%) and norisoprenoids (30 to 70%) was recorded, whereas colored glass bottles did not evidence such behavior even after 50 d, and darkness preserved the wine’s fruity and flowery aromatic integrity. We also proposed an alternative mechanism for the insurgence of the lightstrike off-odor, which takes the varietal aroma loss into account. In light of this understanding of the flint glass negative impact on white wine aroma identity and sensorial character, this packaging should be strongly discouraged. The same findings should be valid for a wide range of several daily consumed foodstuff where transparent packaging is used.
Phase diagram of superconductivity in the integer quantum Hall regime
Authors: Schirmer Jonathan , Liu C.-X. , Jain J. K.
Published: July 2022

An interplay between pairing and topological orders has been predicted to give rise to superconducting states supporting exotic emergent particles, such as Majorana particles obeying non-Abelian braid statistics. We consider a system of spin polarized electrons on a Hofstadter lattice with nearest-neighbor attractive interaction and solve the mean-field Bogoliubov–de Gennes equations in a self-consistent fashion, leading to gauge-invariant observables and a rich phase diagram as a function of the chemical potential, the magnetic field, and the interaction. As the strength of the attractive interaction is increased, the system first makes a transition from a quantum Hall phase to a skyrmion lattice phase that is fully gapped in the bulk but has topological chiral edge current, characterizing a topologically nontrivial state. This is followed by a vortex phase in which the vortices carrying Majorana modes form a lattice; the spectrum contains a low-energy Majorana band arising from the coupling between neighboring vortex-core Majorana modes but does not have chiral edge currents. For some parameters, a dimer vortex lattice occurs with no Majorana band. The experimental feasibility and the observable consequences of skyrmions as well as Majorana modes are indicated.
Ablation of lysophosphatidic acid receptor 1 attenuates hypertrophic cardiomyopathy in a mouse model
Authors: Axelsson Raja Anna , Wakimoto Hiroko , DeLaughter Daniel M. , Reichart Daniel , Gorham Joshua , Conner David A. , Lun Mingyue , Probst Clemens K. , Sakai Norihiko , Knipe Rachel S. , Montesi Sydney B. , Shea Barry , Adam Leonard P. , Leinwand Leslie A. , Wan William , Choi Esther Sue , Lindberg Eric L. , Patone Giannino , Noseda Michela , Hübner Norbert , Seidman Christine E. , Tager Andrew M. , Seidman J. G. , Ho Carolyn Y.
Published: July 2022

Myocardial fibrosis is a key pathologic feature of hypertrophic cardiomyopathy (HCM). However, the fibrotic pathways activated by HCM-causing sarcomere protein gene mutations are poorly defined. Because lysophosphatidic acid is a mediator of fibrosis in multiple organs and diseases, we tested the role of the lysophosphatidic acid pathway in HCM. Lysphosphatidic acid receptor 1 (LPAR1), a cell surface receptor, is required for lysophosphatidic acid mediation of fibrosis. We bred HCM mice carrying a pathogenic myosin heavy-chain variant (403+/−) withLpar1-ablated mice to create mice carrying both genetic changes (403+/−LPAR1−/−) and assessed development of cardiac hypertrophy and fibrosis. Compared with 403+/−LPAR1WT, 403+/−LPAR1−/−mice developed significantly less hypertrophy and fibrosis. Single-nucleus RNA sequencing of left ventricular tissue demonstrated thatLpar1was predominantly expressed by lymphatic endothelial cells (LECs) and cardiac fibroblasts.Lpar1ablation reduced the population of LECs, confirmed by immunofluorescence staining of the LEC markers Lyve1 and Ccl21a and, by in situ hybridization, forRelnandCcl21a.Lpar1ablation also altered the distribution of fibroblast cell states. FB1 and FB2 fibroblasts decreased while FB0 and FB3 fibroblasts increased. Our findings indicate thatLpar1is expressed predominantly by LECs and fibroblasts in the heart and is required for development of hypertrophy and fibrosis in an HCM mouse model. LPAR1 antagonism, including agents in clinical trials for other fibrotic diseases, may be beneficial for HCM.
Antiprion systems in yeast cooperate to cure or prevent the generation of nearly all [

PSI
+

] and [URE3] prions
Authors: Son Moonil , Wickner Reed B.
Published: July 2022

[

PSI
+

] and [URE3] are prions of
Saccharomyces cerevisiae
based on amyloids of Sup35p and Ure2p, respectively. In normal cells, antiprion systems block prion formation, cure many prions that arise, prevent infection by prions, and prevent toxicity of those prions that escape the other systems. The
upf1Δ
,
ssz1Δ
, and
hsp104
T160M
single mutants each develop [

PSI
+

] at 10- to 15-fold, but the triple mutant spontaneously generates [

PSI
+

] at up to ∼5,000-fold the wild-type rate. Most such [

PSI
+

] variants are cured by restoration of any one of the three defective antiprion systems, defining a previously unknown type of [

PSI
+

] variant and proving that these three antiprion systems act independently. Generation of [

PSI
+

] variants stable in wild-type cells is also increased in
upf1Δ ssz1Δ hsp104
T160M
strains 25- to 500-fold. Btn2 and Cur1 each cure 90% of [URE3] prions generated in their absence, but we find that
btn2Δ
or
cur1Δ
diminishes the frequency of [

PSI
+

] generation in an otherwise wild-type strain. Most [

PSI
+

] isolates in a wild-type strain are destabilized on transfer to a
btn2Δ
or
cur1Δ
host. Single
upf1Δ
or
hsp104
T160M
mutants show the effects of
btn2Δ
or
cur1Δ
but not
upf1Δ ssz1Δ hsp104
T160M
or
ssz1Δ hsp104
T160M
strains. The disparate action of Btn2 on [URE3] and [

PSI
+

] may be a result of [

PSI
+

]’s generally higher seed number and lower amyloid structural stability compared with [URE3]. Thus, prion generation is not a rare event, but the escape of a nascent prion from the surveillance by the antiprion systems is indeed rare.
Remarks on gapless relative clauses and complement clauses in Mandarin Chinese
Authors: Pan Haihua
Published: July 2022

This paper makes remarks on the syntactic status of Gapless Relative Clauses (GRCs) in Mandarin Chinese and shows
that the arguments for their complement status are not supported by the facts in Mandarin Chinese, as almost all the arguments for
the complement clause analysis of GRCs, as presented in Huang (2016), could be argued
to be evidence for the relative clause (RC) analysis of GRCs. The following RC recoverability hierarchy, Argument RC > Adjunct
RC > GRC, is proposed to explain the contrasts discussed in Huang (2016) and this
paper, and the relevant facts and differences could be accounted for if one assumes that the RCs further to the right in the
hierarchy above are more difficult to be recovered than the RCs further to the left in the above hierarchy and should thus occur
closer to the head noun. This paper demonstrates that GRCs are really RCs licensed by a covert semantic variable, and suggests
that the gapless requirement on complement clauses be replaced by the following two conditions: (a) no syntactic gap or semantic
variable exists in the relevant clause that is related to the head noun in question and (b) a semantic condition, to be specified
in this paper, is necessary on the relationship between the clause in question and the modified head noun.
Is it possible to prove the Altaic theory on the basis of negative forms in Mongolian, Manchu and Turkish?
Authors: Dolińska Joanna
Published: July 2022

The research question posed in this article is whether the Altaic theory is possible, if it is discussed on the basis of chosen negative forms in Mongolian, Turkish, Manchu and its Sibe dialect. The supporters of the Altaic theory assume that these languages (and some include Japanese, Korean and Ainu to this list (Miller, 1967)) emerged from the same root. The opponents of this theory think that the similarities in these languages have resulted from historical contacts between their speakers (Doerfer, 1966, p.122). This article consists of the analysis of negative forms in various stages of Mongolian, Manchu and Turkish languages carried out on the basis of literary monuments and contemporary resources. The conclusions concerning the possibility of the Altaic theory based on the described negative forms have been presented at the end, accompanied by the Index of negative particles and suffixes.
Imaging of PbWO4 crystals for G experiment test masses using a laser interferometer
Authors: Assumin-Gyimah K T A , Holt M G , Dutta D , Snow W M
Published: July 2022

It is highly desirable for future measurements of Newton’s gravitational constant G to use test/source masses that allow nondestructive, quantitative internal density gradient measurements. High density optically transparent materials are ideally suited for this purpose since their density gradient can be measured with laser interferometry, and they allow in-situ optical metrology methods for the critical distance measurements often needed in a G apparatus. We present an upper bound on possible internal density gradients in lead tungstate (PbWO4) crystals determined using a laser interferometer. We placed an upper bound on the fractional atomic density gradient in two PbWO4 test crystals of

1

ρ

d
ρ

d
x

<
2.1
×
1

0

−
8

cm−1. This value is more than two orders of magnitude smaller than what is required for G measurements. They are also consistent with but more sensitive than a recently reported measurements of the same samples, using neutron interferometry. These results indicate that PbWO4 crystals are well suited to be used as test masses in G experiments. Future measurements of internal density gradients of test masses used for measurements of G can now be conducted non-destructively for a wide range of possible test masses.
Understanding the nature of students’ experience of pre-university practical work in physics
Authors: Dunnett K
Published: July 2022

Introductory practical work in university physics degrees is dominated by highly constrained and instructions-based tasks with limited value for developing students’ scientific and critical thinking skills. One possible explanation for this may be the assumptions made about new students’ prior experiences. Over the course of 5 years, approximately 800 first year physics students completed a simple survey of the nature of their prior experiences of physics practical work. An informative means of presenting the data and understanding their experiences as either passive or practical, or in terms of their freedom to make decisions, is developed. Most new undergraduate students have some experience of decision making in relation to physics practical work, which should be incorporated into course design. The data also indicates that different education systems provide different opportunities for decision making, illustrating the need to align practical training at a local level.
DFT insights into the selective NH3 sensing mechanism of two dimensional ZnTe monolayer
Authors: Chang Xiao , Li Xiaofang , Xue Qingzhong
Published: July 2022

Exploring novel NH3 sensing materials is crucial in chemical industries, fertilizing plants and medical fields. Herein, for the first time, the NH3 sensing behaviors and sensing mechanisms of two dimensional (2D) ZnTe monolayer are systematically investigated by density functional theory calculations. It is shown that 2D ZnTe monolayer exhibits excellent selective NH3 sensing properties. (220) crystal facet of ZnTe possesses a higher NH3 adsorption energy (−1.59 eV) and a larger charge transfer (0.195e) than (111) and (311) crystal facets. The positive charges could enhance NH3 sensing while the negative charges could reduce NH3 sensing. The NH3 adsorption strengths are significantly improved in O2 atmosphere while it is negligibly affected by N2 atmosphere and H2O atmosphere. Moreover, the presence of Zn vacancy and Fe, Co, Ni doping could improve the NH3 sensing of ZnTe. Additionally, the experimental results confirms that ZnTe possesses a low detection limit of 0.1 ppm NH3. These theoretical predictions and experimental results present a wide range of possibilities for the further development of ZnTe monolayer in NH3 sensing fields.
Elastometry of clot phantoms via magnetomotive ultrasound-based resonant acoustic spectroscopy
Authors: Levy Benjamin E , Oldenburg Amy L
Published: July 2022

Objective. An ultrasound-based system capable of both imaging thrombi against a dark field and performing quantitative elastometry could allow for fast and cost-effective thrombosis diagnosis, staging, and treatment monitoring. This study investigates a contrast-enhanced approach for measuring the Young’s moduli of thrombus-mimicking phantoms. Approach. Magnetomotive ultrasound (MMUS) has shown promise for lending specific contrast to thrombi by applying a temporally modulated force to magnetic nanoparticle (MNP) contrast agents and measuring resulting tissue displacements. However, quantitative elastometry has not yet been demonstrated in MMUS, largely due to difficulties inherent in measuring applied magnetic forces and MNP densities. To avoid these issues, in this work magnetomotive resonant acoustic spectroscopy (MRAS) is demonstrated for the first time in ultrasound. Main results. The resonance frequencies of gelatin thrombus-mimicking phantoms are shown to agree within one standard deviation with finite element simulations over a range of phantom sizes and Young’s moduli with less than 16% error. Then, in a proof-of-concept study, the Young’s moduli of three phantoms are measured using MRAS and are shown to agree with independent compression testing results. Significance. The MRAS results were sufficiently precise to differentiate between thrombus phantoms with clinically relevant Young’s moduli. These findings demonstrate that MRAS has potential for thrombus staging.
A study on MOCVD growth window for high quality N-polar GaN for vertical device applications
Authors: Soman Rohith , Noshin Maliha , Chowdhury Srabanti
Published: July 2022

Lateral N-polar GaN devices have outperformed Ga-polar GaN counterparts in mm-wave applications. A vertical N-polar GaN device structure with higher breakdown voltage is expected to further improve the output power density. This paper is aimed at understanding the growth conditions for such a vertical N-polar GaN device stack. A vertical device stack requires high-quality n-GaN layer with low unintentional dopant concentration and high electron mobility for better ON resistance–breakdown voltage performance. A systematic study by varying reactor temperature, pressure and NH3 flow rate is performed in the metal organic chemical vapor deposition growth of N-polar GaN for vertical device structure. Structural quality of the sample is increased with increase growth temperature and higher NH3 flow rate, yet an increase in surface roughness is observed for highest temperature used. The N-polar GaN grown at the optimized conditions exhibited a x-ray diffraction rocking curve full width half maximum of symmetric (0002) and skew-symmetric (20

2
ˉ

1
ˉ

) scans of 358″ and 569″ respectively with a low oxygen and carbon concentration of 6 × 1016 cm−3 and 5 × 1016 cm−3, respectively. The optimized sample exhibited a low screw dislocation density of 2.5 × 108 cm−2 on sapphire substrate. A gradual increase in the bulk mobility of electrons with decrease in screw dislocation density in N-polar GaN is also reported.
Evolutionary algorithm to design high-cooperativity optical cavities
Authors: Karpov Denis , Horak Peter
Published: July 2022

Using an evolutionary algorithm combined with a gradient descent (GD) method we design optical cavities with significantly enhanced strong coupling rates between cavity photons and a single quantum emitter. Our approach allows us to find specially designed non-spherical mirrors which lead to high-finesse cavity eigenmodes with large field enhancement at the center of the cavity. The method is based on adding consecutive perturbations to an initial spherical mirror shape using the GD method for optimization. We present mirror profiles which demonstrate higher cavity cooperativity than any spherical cavity of the same size. Finally, we demonstrate numerically how such a cavity enhances the operation frequency and purity of coupling a Ca+ ion to an optical fiber photon.
Quantum entangled fractional Fourier transform based on the IWOP technique
Authors: Zhang Ke , Li Lan-Lan , Yu Pan-Pan , Zhou Ying , Guo Da-Wei , Fan Hong-Yi
Published: July 2022

In our previous papers, the classical fractional Fourier transform theory was incorporated into the quantum theoretical system using the theoretical method of quantum optics, and the calculation produced quantum mechanical operators corresponding to the generation of fractional Fourier transform. The core function of the coordinate–momentum exchange operators in the addition law of fractional Fourier transform was analyzed too. In this paper, the bivariate operator Hermite polynomial theory and the technique of integration within an ordered product of operators (IWOP) are used to establish the entanglement fractional Fourier transform theory to the extent of quantum. A new function generating formula and an operator for generating quantum entangled fractional Fourier transform are obtained using the fractional Fourier transform relationship in a pair of conjugated entangled state representations.
Fiber cladding dual channel surface plasmon resonance sensor based on S-type fiber
Authors: Wei Yong , Zhao Xiaoling , Liu Chunlan , Wang Rui , Jiang Tianci , Li Lingling , Shi Chen , Liu Chunbiao , Zhu Dong
Published: July 2022

Fiber cladding surface plasmon resonance (SPR) sensors have few structures, and a clad SPR sensor based on S-type fiber is proposed in this paper. This new type of fiber cladding SPR sensor was formed by electrofusing an S-shaped structure on the fiber to couple the light in the fiber core to the cladding. In this paper, the effects of fiber parameters on the performance of the sensor were studied by simulation and experiment. Based on the conclusion that the smaller the core diameter is, the closer the working band of the SPR resonance is to long wavelengths, and that the geometric characteristics mean that a multimode fiber can receive the fiber cladding light from a small core diameter few-mode fiber, a dual channel SPR sensor with a double S-type fiber cascade was proposed. In the refractive index detection range of 1.333–1.385 refractive index units (RIU), the resonant working band of channel I is 627.66 nm–759.78 nm, with an average sensitivity of 2540.77 nm/RIU, and the resonant working band of channel II is 518.24 nm–658.2 nm, with an average sensitivity of 2691.54 nm/RIU. The processing method for the S-type fiber cladding SPR sensor is simple, effectively solving the problem of this type of SPR sensor structure and the difficult realization of a dual channel. The sensor is expected to be used in the fields of medical treatment and biological analysis.
Plasma flow measurements based on charge exchange recombination spectroscopy in the Wendelstein 7-X stellarator
Authors: Alonso J.A. , Ford O.P. , Vanó L. , Äkäslompolo S. , Buller S. , McDermott R. , Smith H.M. , Baldzuhn J. , Beidler C.D. , Beurskens M. , Bozhenkov S. , Brunner K.J. , Calvo I. , Carralero D. , Dinklage A. , Estrada T. , Fuchert G. , Geiger J. , Knauer J. , Langenberg A. , Pablant N.A. , Pasch E. , Poloskei P.Zs. , Velasco J.L. , Windisch T. , the W7-X Team
Published: July 2022

The initial operation of neutral beams in Wendelstein 7-X enabled the first measurements of carbon (C6+) temperature and rotation with a multi-chord charge exchange recombination spectroscopy system. In this article we analyse the velocity measurements obtained with this system to infer the profiles of radial electric field, E
r, and net parallel velocity of fully stripped carbon ions, V
‖. We include a general treatment of the flow geometry and the velocity corrections due to the energy dependence of the charge exchange cross section. The inverted profiles are compared with neoclassical calculations for various plasma conditions and two magnetic configurations. It is found that both the E
r and V
‖ experimental profiles agree in sign and order of magnitude with the neoclassical expectations and reproduce the expected dependencies on plasma parameters and magnetic configuration, within the reduced dataset presented. However, quantitative differences with respect to the neoclassical profiles are observed above the estimated errors in various conditions.
Implementation of microseismic monitoring for iron ore mines
Authors: Bakai A V
Published: July 2022

The seismic station of the Subbot Institute of Geophysics of the NAS of Ukraine (IGP), in Kriviy Rih (Ukraine) ten earthquakes were registered from 2007 to 2013. Such activity is not typical for this region. One of the reasons is mining of mineral resources in this area, leading to irreversible changes in the stress-strain state of the massif, which activate dangerous natural and man-made processes (landslides, flooding, earthquakes, mountain strikes, etc.) The collapse of the mountain massif and the exit of the funnels occurs when the limit value of the loading in the massif is reached. Limit value warning of the stress-strain state of the massif is a condition for the danger of the zone. The task of control is to prevent the stress-strain state of the massif. Any unloading of the massif is accompanied by the formation of a crack, which is characterized by a burst of amplitude and a certain frequency of oscillations. For the geographic information system of mines, it is important to highlight significant phenomena by types of energy, affiliation to the mining allotment of the mine (distance to the hypocenter) and the nature of the primary source - technical or natural. The goal of research is to define a significant phenomena for identifying the stress-strain state of the massif using the microseismic monitoring. To increase noise immunity, it is advisable to use both physical filtration methods and software selection of significant phenomena against the background of man-made noise. To form conclusions, it is necessary to form a sample, so for reliable identification of the stress - strain state of the massif it is necessary to perform statistical processing of the measurement results. The usage of microseismic control at mining enterprises will reduce the possibility of mining shocks, landslides, which will reduce material damage. This will increase the safety of mining operations and ability to prevent man-made earthquakes of magnitude more than five.
Stress environment around head entries with pillarless gobside entry retaining through numerical simulation incorporating the two type of filling wall
Authors: Sakhno I G , Sakhno S V , Kamenets V I
Published: July 2022

Longwall mining is the most productive system for underground extraction of coal. Many coal mines use a pillarless mining. Reserving a gateroad for the usage of next panel mining is a popular gob-side entry retaining. Thus, the conventional entry retaining method requires an installation of filling walls. The mechanical properties of filling materials largely determine the quality of job-side entry retaining. Stress field evolution study around head entries when main roof console length increase with two variants of filling wall. Ansys code was used to analyze the stress evolution law under different mining conditions. As a result of numerical simulation, it was found that in the case of gob-side entry retaining, the localization of maximum stresses in surrounding rock is determined by the length console of the main roof, which hanging on the border with the gob, and the filling walls deformation module. Potential location of roof cutting, stress gradient and extremum stress in the main roof define the stability of entries. Main roof console length and filling material parameters control can help to the formation of a stable structure around the entry to meet the requirements of the next working face.
Immobilization of boronic acid derivative onto the magnetic Gd-containing composites
Authors: Pylypchuk Ie V , Kovach V O , Iatsyshyn Anna V , Farrakhov O V , Bliznyuk V N , Kutsenko V O
Published: July 2022

Aiming to develop new magnetic materials for neutron shielding applications, B- and Gd-containing magnetic nanoparticles were synthesized. Following bottom-up synthetic approach, core-shell Fe
3
O
4/Gd
2
O
3 nanocomposite particles were synthesized at the first stage. In the next stage, magnetic core-shell particles were modified with amino groups followed by grafting onto their surface of the boronic acid derivative. Such a multifunctional material, containing both boron (B) and gadolinium (Gd) atoms is a promising candidate for developing films and membranes, strongly interacting with neutrons. Due to the presence of boronic acids and bound to the indicator (Alizarin Red S), the material can induce color changes while immersed in sugar-containing solutions. Such a feature enables a possibility to estimate the number of boron atoms left after interaction with neutrons, thus allowing to check composite neutron-capture recourse.
Human-centered management in polyergatic information systems. Multi-criteria distribution of functions between operators
Authors: Lavrov E A , Siryk O E , Chybiriak Y I , Zolkin A L , Sedova N A
Published: July 2022

The article considers the problem of human factor in complex polyergatic systems with a flow of applications for functions (problem solving) arising at random moments of time. The structure of a decision support system for the operator-manager, including subsystems of monitoring, forecasting and decision-making, is justified. The system of criteria relevant to solving the tasks of functions distribution was substantiated and its multi-criteria nature was shown. The technology of multi-criteria evaluation and choice of alternatives based on the methodology of hierarchical system analysis of problems and the method of analysis of hierarchies Thomas Saaty has been proposed. The decision-making system, which has been tested in the operation of control systems of various complex technical and production objects, has been implemented. The proposed method differs from the known approaches in that this method is aimed at prompt decision-making, as well as in that it uses a multi-criteria approach and both pragmatic and ergonomic criteria are used as criteria.
Adapting engineering education to challenges of sustainable development
Authors: Derkach T M , Shuhailo Ya V
Published: July 2022

Textile and clothing industries generate a lot of waste at both production stages and in the process of wearing garments. Every inhabitant of developed countries annually wastes up to 30 kg of used but still suitable clothes, which decompose very slowly in natural conditions. The broadest possible implementation of textile waste processing technologies, such as downcycling and upcycling, is the key to ensuring the successful operation of the textile and clothing industries under conditions of sustainable development. The paper goal is to determine factors controlling students’ upcycling behaviour to strengthen the educational components and meet sustainable development challenges for the garment industry. Based on interpersonal and planned behaviour models, 93 students of 1-6 years majoring in clothing technology, design and sectoral professional education were surveyed to understand their upcycling behaviour. The surveyed students are divided into similar-sized groups of optimists (practice upcycling more than once every three months) and pessimists (less than once a year). Upcycling behaviour was shown to correlate with intentions, which are, in turn, affected by social factors, attitude, and perceived behaviour control. Perceived habits and facilitating conditions have a relatively small impact. There is almost no difference between students of different years of study and specialities. Students’ understanding of the benefits of upcycling is shallow and does not change with training years. Amid a highly-positive attitude towards upcycling, a low level of knowledge of the benefits and lack of progress with years indicate existing problems in developing upcycling behaviour in the learning process.
Seafarers high quality training provision by means of VR technologies in the context of maritime transport sustainability
Authors: Voloshynov S A , Popova H V , Dyagileva O S , Fedorova O V , Bobrysheva N N
Published: July 2022

The solution to a number of global problems nowadays depends on the nature of human interaction with the world’s oceans. The constant growth in shipping operations requires ensuring the environmental safety of the planet and belongs to strategic targets of the environmental policy of IMO Convention (International Maritime Organization) in the context of sustainable development of the maritime industry. The aim of the study is the necessity to form ecological consciousness of future seafarers by means of educational VR technologies. The issue of the effective use of cloud computing and VR technologies is considered throughout the research. The definitions of simulation and distance educational technologies, their role in the formation of environmental competence of seafarers are revealed on the example of applying the “Safe Tank Cleaning Operation” course with the use of projected virtual reality simulator. According to the experiment’s results the quality of environmental competence formation in experimental group is 88% and in control group - 82%. The research reflects modern approaches and describes a methodology for acquiring practical skills by means of VR simulation technologies. The authors have shown the effectiveness of practical skills mastering by using VR simulators in the process of forming the environmental competence of seafarers.
Seeds on a parachute: the technology of greening
Authors: Zdeshchyts A V , Zdeshchyts V M
Published: July 2022

To strengthen the sides of tailing dams and stockpiles, it growing forests from trees, shrubs and plant grass. Due to the difficult topography of the terrain, greening technologies require new ideas and material support. The objective of the research is to develop a technology for sowing large areas of plants with seeds from the air. In order to sow large areas with plants, it proposed to scatter seeds (grains) from a height onto hard-to-reach slopes, attached to a parachute system of a special design. Thousands of swarms of miniature capsules with seeds lifted by the drone and released by it at a given height will be scattered by the wind over large cultivated areas. The capsule filled with grain, fertilizer, humus and a compartment with water (gel). The parachute system is a three-dimensional paper platform that allows the capsule attached to it to fall smoothly and slowly. The hooked plumage of the platform provides its reliable grip on the ground. The platform is also soaked with seed nutrients before launch. Analytical, computational and experimental studies have confirmed the highly efficient aerodynamic properties of the developed parachute systems. 3D flying platforms demonstrated controlled rotation kinematics (18 rad/s) and low final speeds of 1.6-1.9 m/s.