bluuebunny/crossref_metadata_2025 huggingface dataset:
A general method for locating stationary points on the mixed-spin surface of spin-forbidden reaction with multiple spin states
Authors: Zhao Long , Zou Wenli
Published: June 2023

Some chemical reactions proceed on multiple potential energy surfaces and are often accompanied by a change in spin multiplicity, being called spin-forbidden reactions, where the spin–orbit coupling (SOC) effects play a crucial role. In order to efficiently investigate spin-forbidden reactions with two spin states, Yang et al. [Phys. Chem. Chem. Phys. 20, 4129–4136 (2018)] proposed a two-state spin-mixing (TSSM) model, where the SOC effects between the two spin states are simulated by a geometry-independent constant. Inspired by the TSSM model, we suggest a multiple-state spin-mixing (MSSM) model in this paper for the general case with any number of spin states, and its analytic first and second derivatives have been developed for locating stationary points on the mixed-spin potential energy surface and estimating thermochemical energies. To demonstrate the performance of the MSSM model, some spin-forbidden reactions involving 5d transition elements are calculated using the density functional theory (DFT), and the results are compared with the two-component relativistic ones. It is found that MSSM DFT and two-component DFT calculations may provide very similar stationary-point information on the lowest mixed-spin/spinor energy surface, including structures, vibrational frequencies, and zero-point energies. For the reactions containing saturated 5d elements, the reaction energies by MSSM DFT and two-component DFT agree very well within 3 kcal/mol. As for the two reactions OsO+ + CH4 → OOs(CH2)+ + H2 and W + CH4 → WCH2 + H2 involving unsaturated 5d elements, MSSM DFT may also yield good reaction energies of similar accuracy but with some counterexamples. Nevertheless, the energies may be remarkably improved by a posteriori single point energy calculations using two-component DFT at the MSSM DFT optimized geometries, and the maximum error of about 1 kcal/mol is almost independent of the SOC constant used. The MSSM method as well as the developed computer program provides an effective utility for studying spin-forbidden reactions.
Numerical study of ultrasonic Rayleigh wave fields scattered by vertical cracks buried in half-space
Authors: Zhang Shuzeng , Wang Lei , Li Xiongbing , Shi Wenze , Lu Chao
Published: June 2023

In this study, the properties of Rayleigh wave fields scattered at a surface from open vertical cracks with different shapes are investigated. The scattered Rayleigh wave is determined by both the incident Rayleigh wave and its interaction with the crack, and the wave fields are modeled using the Green's function method based on the reciprocity theorem. The reflection coefficient of the Rayleigh wave in two-dimensional coordinates is employed to simplify the area integration over the crack surface for the scattered Rayleigh wave to a line integration over the length of the crack. Numerical simulations are carried out, and the effects of the crack length and depth on the scattered Rayleigh wave fields are discussed. The results indicate that the distribution of a scattered Rayleigh wave field is mainly determined by the crack length, while the amplitude is closely related to the crack depth. Since the reflection coefficient becomes almost stable when the ratio of the crack depth to the Rayleigh wavelength is larger than 1, the variation in the scattered Rayleigh wave field is insignificant for cracks with the same length but varying depths. This work will be helpful for solving the inverse problem of evaluating crack geometry using ultrasonic Rayleigh waves and for further work on Rayleigh waves scattered by cracks with different directions of extension and angles with the surface.
Resonant states in 2D disordered photonic bandgap structures
Authors: Andueza Angel , Pérez-Conde Jesús , Sevilla Joaquín
Published: June 2023

During the last decades, 2D-ordered and disordered photonic systems have attracted intense attention as systems capable to control and modify the flow of light. These structures can also localize light into a bandgap by exciting states arising from cavities, defects, or photonic molecules. We report a controllable random disordered photonic system of silicon dielectric cylinders that presents a deep bandgap and, superimposed, two tunable resonant states generated from decagonal ring resonators embedded into it. These states show a high transmission intensity and a bandwidth that remains stable when its geometrical parameters for frequency tuning are modified. The ability to tune resonating frequencies with geometrical parameters of the system allows interesting applications such as sensing and filtering.
Interplay of multiple clusters and initial interface positioning for forward flux sampling simulations of crystal nucleation
Authors: Blow Katarina E. , Tribello Gareth A. , Sosso Gabriele C. , Quigley David
Published: June 2023

Forward flux sampling (FFS) is a path sampling technique widely used in computer simulations of crystal nucleation from the melt. In such studies, the order parameter underpinning the progress of the FFS algorithm is often the size of the largest crystalline nucleus. In this work, we investigate the effects of two computational aspects of FFS simulations, using the prototypical Lennard-Jones liquid as our computational test bed. First, we quantify the impact of the positioning of the liquid basin and first interface in the space of the order parameter. In particular, we demonstrate that these choices are key to ensuring the consistency of the FFS results. Second, we focus on the frequently encountered scenario where the population of crystalline nuclei is such that there are multiple clusters of size comparable to the largest one. We demonstrate the contribution of clusters other than the largest cluster to the initial flux; however, we also show that they can be safely ignored for the purposes of converging a full FFS calculation. We also investigate the impact of different clusters merging, a process that appears to be facilitated by substantial spatial correlations—at least at the supercooling considered here. Importantly, all of our results have been obtained as a function of system size, thus contributing to the ongoing discussion on the impact of finite size effects on simulations of crystal nucleation. Overall, this work either provides or justifies several practical guidelines for performing FFS simulations that can also be applied to more complex and/or computationally expensive models.
Effects of time-filtering the Navier–Stokes equations
Authors: Oberle Daniel , Pruett C. David , Jenny Patrick
Published: June 2023

The underlying premise of temporal large eddy simulation (TLES) is that the attenuation of high-frequency content also attenuates the high-wavenumber content. Yet, to date, the effect in wavenumber space of removing high-frequency oscillations by time-domain filtering is not well understood. In this work, we numerically investigate the relationship between the frequency and wavenumber with particular attention to the role of the temporal residual-stress in TLES. Moreover, since under-resolved simulations that use high-order, non-dissipative numerical methods require some measure of artificial dissipation for stabilization, we also discuss the regularization term with practical relevance to under-resolved applications of TLES. Specifically, we analyze the effects of Eulerian time-domain filtering with a causal exponential filter on homogeneous isotropic turbulence. The data are generated by direct numerical simulation of the Navier–Stokes equations, which are driven to maintain an average Reynolds number (Reλ) of 200. A priori, Fourier transformations of the velocity fields were performed in order to compute the unfiltered and filtered energy and dissipation spectra in both wavenumber space and wavenumber–frequency space. Furthermore, the amount of unresolved dissipation of an insufficiently resolved simulation was approximated in an attempt to estimate the required additional artificial dissipation. The results indicate that the numerically motivated stabilization term can be reduced due to temporal filtering. Moreover, it has been shown that a sharp cutoff in the frequency domain does not translate into a sharp cutoff in the wavenumber space. Thus, a hybrid model that combines temporal filtering for the residual-stress and spatial filtering for stabilization might be advantageous.
Coarse-grained modeling of polymers with end-on and side-on liquid crystal moieties: Effect of architecture
Authors: Becerra Diego , Jois Pranav R. , Hall Lisa M.
Published: June 2023

Mesogens, which are typically stiff rodlike or disklike molecules, are able to self-organize into liquid crystal (LC) phases in a certain temperature range. Such mesogens, or LC groups, can be attached to polymer chains in various configurations including within the backbone (main-chain LC polymers) or at the ends of side-chains attached to the backbone in an end-on or side-on configuration (side-chain LC polymers or SCLCPs), which can display synergistic properties arising from both their LC and polymeric character. At lower temperatures, chain conformations may be significantly altered due to the mesoscale LC ordering; thus, when heated from the LC ordered state through the LC to isotropic phase transition, the chains return from a more stretched to a more random coil conformation. This can cause macroscopic shape changes, which depend significantly on the type of LC attachment and other architectural properties of the polymer. Here, to study the structure–property relationships for SCLCPs with a range of different architectures, we develop a coarse-grained model that includes torsional potentials along with LC interactions of a Gay–Berne form. We create systems of different side-chain lengths, chain stiffnesses, and LC attachment types and track their structural properties as a function of temperature. Our modeled systems indeed form a variety of well-organized mesophase structures at low temperatures, and we predict higher LC-to-isotropic transition temperatures for the end-on side-chain systems than for analogous side-on side-chain systems. Understanding these phase transitions and their dependence on polymer architecture can be useful in designing materials with reversible and controllable deformations.
Field dipole interaction and polarization effects in light-sheet optical fluorescence microscopy
Authors: Kumar Prashant , Mondal Partha Pratim
Published: June 2023

Polarization plays a crucial role in understanding the interaction of fluorescent molecules in a light field. We report the study on the effect of a field–dipole interaction under polarization light-sheet fluorescence microscopy using the vectorial theory of light. The molecule is suitably modeled as a radiating electric dipole in a polarized electric field (both linear and random), and the system point spread function (PSF) is determined for different orientations of the dipole (both fixed and random). PSF analysis and contour plots suggest distinct nature of a field distribution in each case, indicating the importance of a field–dipole interaction for high-quality fluorescence imaging. The analysis suggests that the field spreads gradually along the polarization axis at a high numerical aperture (NA) of the objective lens, whereas it is more isotropic and homogeneous at low NA. Moreover, fast changes are not observed at low NA (i.e., far from the central lobe in the field contour plots), suggesting the absence of high-frequency components. However, sidelobes are prominent for linear polarized (along x) light. On the other hand, rapid variations are evident for randomly polarized light, depicting the presence of high spatial frequencies in the system optical transfer function. The other significant observation is the distinct frequency spectrum (both kx and ky) for random and fixed dipoles, indicating the significance of dipole orientation in a light-sheet field. Compared to the point-illumination-based fluorescence microscopy, sheet based polarization technique provides a high signal-to-noise ratio, a uniform field, an order large field of view, and critical information (related to the micro-environment of a dipole and its short-range interactions). The study is expected to facilitate polarization-sensitive investigation of large biological specimens (both fixed and live).
Vacancy-type defects in AlInN/AlN/GaN structures probed by monoenergetic positron beam
Authors: Uedono Akira , Kimura Yasuki , Hoshii Takuya , Kakushima Kuniyuki , Sumiya Masatomo , Tsukui Masayuki , Miyano Kiyotaka , Mizushima Ichiro , Yoda Takashi , Tsutsui Kazuo
Published: June 2023

Vacancy-type defects in AlInN(10 nm)/AlN(1–2 nm)/GaN were probed by using a positron annihilation technique. The crystal quality of the AlInN layer and atomic diffusion near heterointerfaces were also studied by x-ray diffraction reciprocal space mapping, transmission electron microscopy, and energy-dispersive x-ray spectroscopy. For an as-deposited sample without an AlN spacer layer (AlInN/GaN), Ga atoms diffused into the AlInN layer, and as a result, the concentration of Ga-vacancy-type defects in the GaN layer increased. The vacancy concentration was decreased by inserting the AlN layer, which was attributed to the suppression of out-diffusion of Ga from the GaN layer. The effect of the thickness of the AlN layer on the mobility of two-dimensional electron gas is discussed in terms of the introduction of vacancies into the channel region. The annealing behaviors of vacancies in the GaN layer and atomic exchange near heterointerfaces are also discussed.
Boron coordination change in barium borate melts and glasses and its contribution to configurational heat capacity, entropy, and fragility
Authors: Alderman O. L. G. , Benmore C. J. , Holland D. , Weber J. K. R.
Published: June 2023

High-energy x-ray diffraction from molten and glassy BaB2O4 and BaB4O7 has been performed using aerodynamic levitation and laser heating over a wide range of temperatures. Remarkably, even in the presence of a heavy metal modifier dominating x-ray scattering, it was possible to extract accurate values for the tetrahedral, sp3, boron fraction, N4, which declines with increasing temperature, using bond valence-based mapping from the measured mean B–O bond lengths while accounting for vibrational thermal expansion. These are used within a boron-coordination-change model to extract enthalpies, ΔH, and entropies, ΔS, of isomerization between sp2 and sp3 boron. The results for BaB4O7, ΔH = 22(3) kJ mol−1 boron, ΔS = 19(2) J mol−1 boron K−1, agree quantitatively with those found previously for Na2B4O7. Analytical expressions for N4(J, T) and associated configurational heat capacity, CPconf(J, T), and entropy, Sconf(J, T), contributions are extended to cover a wide composition range 0 ≤ J = BaO/B2O3 ≤ 3 using a model for ΔH(J) and ΔS(J) derived empirically for lithium borates. Maxima in the CPconf(J, Tg) and fragility index contributions are thereby predicted for J ≲ 1, higher than the maximum observed and predicted in N4(J, Tg) at J ≃ 0.6. We discuss the utility of the boron-coordination-change isomerization model in the context of borate liquids containing other modifiers and the prospect of neutron diffraction to aid in empirical determinations of modifier-dependent effects, illustrated by new neutron diffraction data on Ba11B4O7 glass, its well-known α-polymorph, and lesser-known δ-phase.
Wake up and retention in zinc magnesium oxide ferroelectric films
Authors: Jacques Leonard , Ryu Gyunghyun , Goodling Devin , Bachu Saiphaneendra , Taheri Rojin , Yousefian Pedram , Shetty Smitha , Akkopru-Akgun Betul , Randall Clive , Alem Nasim , Maria Jon-Paul , Trolier-McKinstry Susan
Published: June 2023

Zn0.64Mg0.36O (ZMO) is a newly discovered ferroelectric oxide with the wurtzite structure. Epitaxial Zn0.64Mg0.36O films from 0.036 to 0.5 μm in thickness are grown on Pt/sapphire with the crystallographic c-axis out of plane. At room temperature, the remanent polarization is ∼80 μC/cm2 and the coercive field is ∼3 MV/cm. The coercive field is strongly temperature dependent up to 240 °C with a pseudo-activation energy of 23 ± 0.3 meV, suggesting that polarization reversal occurs through an extrinsic process such as domain wall motion. ZMO films can be woken up in 20 electric field cycles on driving near the coercive field; they wake up in a single loop at fields in excess of 4 MV/cm. A thermally activated fluid imprint process, with a pseudo-activation energy of 67 ± 8 meV, enlarges the coercive field by several hundred kV cm−1 after switching the polarization. Additionally, ZMO films exhibit excellent retention characteristics; no reduction in the polarization is observed up to 1000 h from room temperature to 200 °C bakes. This current early generation of ZMO films can survive several thousand switching cycles before dielectric breakdown occurs.
On the phase behaviors of CH4–CO2 binary clathrate hydrates: Two-phase and three-phase coexistences
Authors: Tanaka Hideki , Matsumoto Masakazu , Yagasaki Takuma
Published: June 2023

We develop a statistical mechanical theory on clathrate hydrates in order to explore the phase behaviors of clathrate hydrates containing two kinds of guest species and apply it to CH4–CO2 binary hydrates. The two boundaries separating water and hydrate and hydrate and guest fluid mixtures are estimated, which are extended to the lower temperature and the higher pressure region far distant from the three-phase coexisting conditions. The chemical potentials of individual guest components can be calculated from free energies of cage occupations, which are available from intermolecular interactions between host water and guest molecules. This allows us to derive all thermodynamic properties pertinent to the phase behaviors in the whole space of thermodynamic variables of temperature, pressure, and guest compositions. It is found that the phase boundaries of CH4–CO2 binary hydrates with water and with fluid mixtures locate between simple CH4 and CO2 hydrates, but the composition ratios of CH4 guests in hydrates are disproportional to those in fluid mixtures. Such differences arise from the affinities of each guest species to the large and small cages of CS-I hydrates and significantly affect occupation of each cage type, which results in a deviation of the guest composition in hydrates from that in fluid on the two-phase equilibrium conditions. The present method provides a basis for the evaluation of the efficiency of the guest CH4 replacement to CO2 at the thermodynamic limit.
Changing patterns of otitis media in the Waikato region during the COVID-19 pandemic
Authors: Becker Andre , Nguyen Ha , Becker Michael , Wood Andrew , Lawrenson Ross
Published: June 2023

Introduction Acute otitis media (AOM) is a common condition of children encountered in general practice. A proportion of children develop otitis media with effusion (OME), which may require tympanostomy and ventilation tube insertion. Aim The aim of the study was to compare the incidence of AOM in Māori and New Zealand (NZ) European children in general practice and the referral practices to secondary care for tympanostomy and ventilation tube insertion. Methods The study was conducted in two parts: (1) an analysis of the incidence of AOM and OME in a rural Waikato general practice (Ōtorohanga) with a high Māori population over a 2-year period; and (2) an analysis of all referrals to the otorhinolaryngology (ORL) department at Waikato District Health Board and tympanostomy and ventilation tube insertion by this service over the same period. Results The incidence of AOM was similar in Māori compared with NZ European children. The incidence declined significantly between 2019 and 2020 and 50% of children with AOM were treated with antibiotics. Referral rates to the ORL department were greater for Māori compared with NZ European children as were tympanostomy and ventilation tube insertion rates. Discussion Although AOM is common, OME was rarely diagnosed. The clinical guidelines regarding antibiotic use for common conditions are not being readily adopted and further research is needed into this matter. The COVID-19 pandemic had a substantial effect on demand both in general practice and in the hospital sector. This may have been due to a reduction in the incidence of AOM or due to system changes caused by the pandemic.
The melatonin system is expressed in the ovine uterus: effect of the day of the oestrous cycle and undernutrition
Authors: Sosa C. , Laurenzana E. , de Brun V. , Meikle A. , Abecia J. A.
Published: June 2023

Context Melatonin influences female reproduction, but expression of the melatonin system has not been characterised in the ovine uterus. Aims We aimed to determine whether synthesising enzymes (arylalkylamine N-acetyltransferase (AANAT) and N-acetylserotonin-O-methyltransferase (ASMT)), melatonin receptors 1 and 2 (MT1 and MT2), and catabolising enzymes (myeloperoxidase (MPO) and indoleamine 2,3-dioxygenase 1 and 2 (IDO1 and 2)), are expressed in the ovine uterus, and if they are influenced by the oestrous cycle (Experiment 1) or by undernutrition (Experiment 2). Methods In Experiment 1, gene and protein expression was determined in sheep endometrium samples collected on days 0 (oestrus), 5, 10 and 14 of the oestrous cycle. In Experiment 2, we studied uterine samples from ewes fed either 1.5 or 0.5 times their maintenance requirements. Key results We have demonstrated the expression of AANAT and ASMT in the endometrium of sheep. AANAT and ASMT transcripts, and AANAT protein were more elevated at day 10, then decreased to day 14. A similar pattern was observed for MT2, IDO1, and MPO mRNA, which suggests that the endometrial melatonin system might be influenced by ovarian steroid hormones. Undernutrition increased AANAT mRNA expression, but seemed to decrease its protein expression, and increased MT2 and IDO2 transcripts, whereas ASMT expression was unaffected. Conclusions The melatonin system is expressed in the ovine uterus and is affected by oestrous cycle and undernutrition. Implications The results help explain the adverse effects of undernutrition on reproduction in sheep, and the success of exogenous melatonin treatments in improving reproductive outcomes.
Contrastive learning in protein language space predicts interactions between drugs and protein targets
Authors: Singh Rohit , Sledzieski Samuel , Bryson Bryan , Cowen Lenore , Berger Bonnie
Published: June 2023

Sequence-based prediction of drug–target interactions has the potential to accelerate drug discovery by complementing experimental screens. Such computational prediction needs to be generalizable and scalable while remaining sensitive to subtle variations in the inputs. However, current computational techniques fail to simultaneously meet these goals, often sacrificing performance of one to achieve the others. We develop a deep learning model, ConPLex, successfully leveraging the advances in pretrained protein language models (“PLex”) and employing a protein-anchored contrastive coembedding (“Con”) to outperform state-of-the-art approaches. ConPLex achieves high accuracy, broad adaptivity to unseen data, and specificity against decoy compounds. It makes predictions of binding based on the distance between learned representations, enabling predictions at the scale of massive compound libraries and the human proteome. Experimental testing of 19 kinase-drug interaction predictions validated 12 interactions, including four with subnanomolar affinity, plus a strongly binding EPHB1 inhibitor (
K

D

= 1.3 nM). Furthermore, ConPLex embeddings are interpretable, which enables us to visualize the drug–target embedding space and use embeddings to characterize the function of human cell-surface proteins. We anticipate that ConPLex will facilitate efficient drug discovery by making highly sensitive in silico drug screening feasible at the genome scale. ConPLex is available open source at
https://ConPLex.csail.mit.edu
.
Spreading processes with mutations over multilayer networks
Authors: Sood Mansi , Sridhar Anirudh , Eletreby Rashad , Wu Chai Wah , Levin Simon A. , Yağan Osman , Poor H. Vincent
Published: June 2023

A key scientific challenge during the outbreak of novel infectious diseases is to predict how the course of the epidemic changes under countermeasures that limit interaction in the population. Most epidemiological models do not consider the role of mutations and heterogeneity in the type of contact events. However, pathogens have the capacity to mutate in response to changing environments, especially caused by the increase in population immunity to existing strains, and the emergence of new pathogen strains poses a continued threat to public health. Further, in the light of differing transmission risks in different congregate settings (e.g., schools and offices), different mitigation strategies may need to be adopted to control the spread of infection. We analyze a multilayer multistrain model by simultaneously accounting for i) pathways for mutations in the pathogen leading to the emergence of new pathogen strains, and ii) differing transmission risks in different settings, modeled as network layers. Assuming complete cross-immunity among strains, namely, recovery from any infection prevents infection with any other (an assumption that will need to be relaxed to deal with COVID-19 or influenza), we derive the key epidemiological parameters for the multilayer multistrain framework. We demonstrate that reductions to existing models that discount heterogeneity in either the strain or the network layers may lead to incorrect predictions. Our results highlight that the impact of imposing/lifting mitigation measures concerning different contact network layers (e.g., school closures or work-from-home policies) should be evaluated in connection with their effect on the likelihood of the emergence of new strains.
“What’s your name?”
Authors: Park Yujong
Published: June 2023

This study investigates the role of identification and frame mismatch in Korean telephone call openings using conversation analysis on a series of problematic telephone calls made to the emergency center from a Korean governor (Moon-Soo, Kim) in 2011. Close examination of the problematic interaction indicates how delivering emergency care as a public service may evolve into a dispute in the Korean cultural context of kwandungsengmyeng (“identifying oneself by official status”). A mismatch between frames (Tracy, 1997) can be identified when the governor asks for the name of the answerer instead of presenting the reason for the call. Comparable examples from Korean conversational telephone calls are noted in which the answerer provides their name in the opening moments of the interaction, thereby depicting a strong expectation for identification and recognition in Korean openings. This paper argues that the governor’s actions can be explained by a mismatch between the public and private frames in relation to identification practices. The study findings may highlight the important role that identification and recognition plays in Korean culture and suggest methods through which future problematic emergency calls can be prevented.
A role of functional morphemes in Korean categorial grammars
Authors: Park Jungyeul , Kim Mija
Published: June 2023

This study discusses a role of functional morphemes in Korean categorial grammars, providing the reviews of various types of Korean categorial grammars that have never been conducted so far, notwithstanding many previous studies on them. Previous work has presented different morphological segmentation because of Korean’s agglutinative characteristics, implying that Korean words may contain a different segmentation sequence of morphemes. We focus on functional morphemes in Korean categorial grammars, which have been explored in different ways by previous work. We present detailed analyses for postpositions and verbal endings in categorial grammars, insisting that the functional morphemes in Korean should be treated as part of a word, with the result that their categories do not require to be assigned individually in a syntactic level, and also that it would be more efficient to assign the syntactic categories on the fully inflected lexical word derived by the lexical rule of the morphological processes in the lexicon.
Improvement of predictive ability of self-association model to segregation of liquid Zn−Bi alloys
Authors: Ding Guo-Hua , Liang Li-Meng
Published: June 2023

The self-association model is an effective theoretical method for determining the thermodynamic parameters of immiscible molten binary alloys. However, two important parameters (the ratios of numbers of two atoms in the cluster n and the interchange energy W) in the model had confusing temperature dependences, which prevented the statistical mechanical model from accurately predicting the physical and chemical properties at various temperatures. The ratios of the two atoms in the cluster and the interchange energy were proposed in this study to be linear with temperature, respectively, to analyze the segregation of liquid Zn–Bi alloys. The hypothesis about two key parameters is helpful to predict the segregating nature of liquid Zn–Bi alloys, as evidenced by the good accordance of the predicted thermophysical properties (activity, free energy of mixing, miscibility gap, entropy of mixing, partial molar entropy, and concentration fluctuation) with the existing experimental data.
Numerical simulation of workpiece temperature field during radial shear rolling of biomedical Co-Cr-Mo alloy
Authors: Kin T Yu , Gamin Yu V , Galkin S P , Skugorev A V
Published: June 2023

This paper describes the analysis of temperature field of workpiece during radial shear rolling (RSR) of biomedical Co-28Cr-6Mo alloy. In the process of hot metal forming, the temperature distribution in the deformation zone has a significant influence on the quality and properties of the final product. In some cases, the deformation within a narrow temperature range is required to provide the desired properties. To obtain data on change in temperature, the computer simulation of RSR was carried out using finite element method. According to simulation results, the temperature distribution of bar depending on the variable process parameters such as temperature of workpiece, rotary velocity of rolls, elongation ratio, diameter of workpiece, and temperature of tool was evaluated. It was determined that the most significant parameters influencing on the distribution of the temperature field are the workpiece heating temperature and the rolling speed. The RSR process makes it possible to effectively manage the distribution of temperature field due to selecting technological parameters and, thereby, control the formation of the alloy structure. The data obtained can be useful for developing the modes of RSR of Co–Cr–Mo alloy.
Frequency dependent impedance response analysis of nanocrystalline ZnO chemiresistors
Authors: P V Abhijith , Tom Abin , Urs Kusuma , Prajapati K N , S Sajana , Mitra J , Jaiswal-Nagar Deepshikha , Kamble Vinayak B
Published: June 2023

ZnO is a widely studied gas sensor material and is used in many commercial sensor devices. However, selectivity towards any particular gas remains an issue due to lack of complete knowledge of the gas sensing mechanism of oxide surfaces. In this paper, we have studied the frequency dependent gas sensor response of ZnO nanoparticles of a diameter of nearly 30 nm. A small rise of synthesis temperature from 85 °C to 95 °C in the solvothermal process, shows coarsening by joining and thereby distinct loss of grain boundaries as seen from transmission electron micrographs. This leads to a substantial reduction in impedance, Z (GΩ to MΩ), and rises in resonance frequency f
res (from 1 to 10 Hz) at room temperature. From temperature dependent studies it is observed that the grain boundaries show a Correlated Barrier Hopping mechanism of transport and the hopping range in the grain boundary region is typically 1 nm with a hopping energy of 153 meV. On the other hand, within the grain, it shows a change of transport type from low temperature tunneling to beyond 300 °C as polaron hopping. The presence of disorder (defects) as the hopping sites. The temperature dependence of f
res agrees with different predicted oxygen chemisorbed species between 200 °C to 400 °C. As opposed to the traditional DC response, the AC response in the imaginary part of (Z″) shows gas specific resonance frequencies for each gas, such as NO2, ethanol, and H2. Among the two reducing gases, ethanol and hydrogen; the former shows good dependence on concentration in Z″ whereas the latter shows a good response in f
res as well as capacitance. Thus, the results of frequency dependent response allow us to investigate greater details of the gas sensing mechanism in ZnO, which may be exploited for selective gas sensing.
Calibration of a three-state cell death model for cardiomyocytes and its application in radiofrequency ablation
Authors: Petras Argyrios , Leoni Massimiliano , Guerra Jose M , Gerardo-Giorda Luca
Published: June 2023

Objective. Thermal cellular injury follows complex dynamics and subcellular processes can heal the inflicted damage if insufficient heat is administered during the procedure. This work aims to the identification of irreversible cardiac tissue damage for predicting the success of thermal treatments. Approach. Several approaches exist in the literature, but they are unable to capture the healing process and the variable energy absorption rate that several cells display. Moreover, none of the existing models is calibrated for cardiomyocytes. We consider a three-state cell death model capable of capturing the reversible damage of a cell, we modify it to include a variable energy absorption rate and we calibrate it for cardiac myocytes. Main results. We show how the thermal damage predicted by the model response is in accordance with available data in the literature on myocytes for different temperature distributions. When coupled with a computational model of radiofrequency catheter ablation, the model predicts lesions in agreement with experimental measurements. We also present additional experiments (repeated ablations and catheter movement) to further illustrate the potential of the model. Significance. We calibrated a three-state cell death model to provide physiological results for cardiac myocytes. The model can be coupled with ablation models and reliably predict lesion sizes comparable to experimental measurements. Such approach is robust for repeated ablations and dynamic catheter-cardiac wall interaction, and allows for tissue remodelling in the predicted damaged area, leading to more accurate in-silico predictions of ablation outcomes.
Experimental study on the spatial structures of filament during ELM crash in ELMy H-mode discharge on EAST
Authors: Li(李邦) Bang , Ming(明廷凤) Tingfeng , Li(李彦龙) Yanlong , Zhuang(庄清) Qing , Shi(石奇奇) Qiqi , Deng(邓荣婧) Rongjing , Hou(侯善伟) Shanwei , Long(龙飞飞) Feifei , Wu(邬潇河) Xiaohe , Liu(刘晓菊) Xiaoju , Zeng(曾龙) Long , Xia(夏天阳) Tianyang , Gao(高翔) Xiang , Li(李国强) GuoQiang
Published: June 2023

A high-speed vacuum ultraviolet imaging (VUVI) system with both high temporal and spatial resolutions in the Experimental Advanced Superconducting Tokamak has been developed for the study of the edge/pedestal plasma. Edge localized mode (ELM)-induced filamentary structures have been successfully visualized by the VUVI system during the ELMy high confinement mode (H-mode) discharges. The poloidal mode spacing and the pitch angle are employed to quantitatively characterize the spatial structure of the observed filamentary structures in the imaging data. The poloidal mode spacing of the filamentary structure is found to be proportional to the plasma current. The dominant toroidal mode number decreases as the plasma current ramps up. In addition, the temporal evolution of the pitch angle during an ELM crash was quantitatively investigated. No significant change in the pitch angle is observed during an ELM crash. The dominant toroidal mode number gradually decreases in the rise phase and increases in the decay phase in one ELM crash, respectively.
Plasma-relevant fast electron impact study of difluoromethane
Authors: Li Heng-Hui , Wang Shu-Xing , Zhu Jian-Hui , Nie Zhi-Wei , Chen Jin-Feng , Wang Li-Han , Ma Wan-Lu , Zhu Lin-Fan
Published: June 2023

Difluoromethane (

C

H
2

F
2

) is a commonly used etching gas in manufacturing very-large-scale integrated circuits as the fluorine source. Electron impact excitation cross sections for

C

H
2

F
2

are important input data for modeling the reactive etching plasmas. In this work, we present the experimental generalized oscillator strengths for the

3
s
←
2

b
2

,

1
1

A
2

←
X

1

A
1

, and

3
p
←
2

b
2

transitions on the absolute scale. The measurement was realized by employing the crossed-beam based relative flow technique at an angle-resolved electron energy loss spectrometer, operating at an incident energy of 1500 eV and a resolution of 80 meV. The dipole-forbidden transition

1
1

A
2

←
X

1

A
1

at around 9.7 eV is identified for the first time. The measured data are fitted with the well-known Lassettre formula to yield analytical expressions and optical oscillator strengths at

K

2

=
0

for dipole-allowed transitions. The analytical expressions enable integrations over momentum transfer to obtain the Born integral cross sections for electron impact excitations from the threshold to 5000 eV. The integral cross sections for dipole-allowed transitions are scaled to a more reliable level by using the BE-scaling method. The experimental data can benchmark theoretical calculations and supplement the molecular database for plasma modelers.
Theory of critical phenomena with long-range temporal interaction
Authors: Zeng Shaolong , Zhong Fan
Published: June 2023

We systematically develop theories of critical phenomena with a prior formed memory of a power-law decaying long-range temporal interaction parameterized by a constant θ > 0 for a space dimension d both below and above an upper critical dimension d

c
= 6 − 2/θ. We first provide more evidences to confirm the previous theory that a dimensional constant

d

t

is demanded to rectify a hyperscaling law, to produce correct unique mean-field critical exponents via an effective spatial dimension originating from temporal dimension, and to transform the time and change the dynamic critical exponent. Next, for d < d

c
, we develop a renormalization-group theory by employing the momentum-shell technique to the leading nontrivial order explicitly and to higher orders formally in ϵ = d

c
− d but to zero order in ε = 1 − θ and find that more scaling laws besides the hyperscaling law are broken due to the breaking of the fluctuation-dissipation theorem. Moreover, because dynamics and statics are intimately interwoven, even the static critical exponents involve contributions from the dynamics and hence do not restore the short-range exponents even for θ = 1 and the crossover between the short-range and long-range fixed points is discontinuous contrary to the case of long-range spatial interaction. In addition, a new scaling law relating the dynamic critical exponent with the static ones emerges, indicating that the dynamic critical exponent is not independent. However, once

d

t

is displaced by a series of ϵ and ε such that most values of the critical exponents are changed, all scaling laws are saved again, even though the fluctuation-dissipation theorem keeps violating. Then, for d ≥ d

c
, we develop an effective-dimension theory by carefully discriminating the corrections of both temporal and spatial dimensions and find three different regions. For d ≥ d

c0 = 4, the upper critical dimension of the usual short-range theory, the usual Landau mean-field theory with fluctuations confined to the effective-dimension equal to d

c0 correctly describe the critical phenomena with memory, while for d

c
< d ≤ 4, there exist new universality classes whose critical exponents depend only on the space dimension but not at all on θ. Yet another region consists of d = d

c
only and the previous theory is retrieved. All these results show that the dimensional constant

d

t

is the fundamental ingredient of the theories for critical phenomena with memory. However, its value continuously varies with the space dimension and vanishes exactly at d = 4, reflecting the variation of the amount of the temporal dimension that is transferred to the spatial one with the strength of fluctuations. Moreover, special finite-size scaling appears ubiquitously except for d = d

c0.
GaAs0.95P0.05 single junction solar cell with InP QW in p-i-n region for sub-bandgap photon absorption
Authors: Verma Manish , Routray Soumya R , Sahoo Girija Shanker , Mishra Guru Prasad
Published: June 2023

To improve the the absorption of the incoming light spectrum in the cell, the bandgap modulation is performed in the cell. such a cell is designed here, with the help of quantum well region of InP material and GaInP barrier region. The bandgap engineered GaAsP solar cell having the bandgap of 1.48 eV is utilized along with the InP quantum well material with bandgap energy of 1.35 eV. The quantum well absorbs the lower bandgap photon energy, which improves the photo carriers. A type-A bandgap structure is formed in the quantum well region, which results in enhanced utilization of lower bandgap photon energy. The Analysis show the significant absorption of the incoming light spectrum, which reflects in the improvement of the current density. The trade-off between the short circuit current and open circuit voltage, which happens due to the bandgap modulation, leads to the 20% drop in the open circuit voltage. But, due to larger improvement of 31.06% in the short circuit current leads to the improvement of 4.75% in overall efficiency of the cell. The quantum efficiency of the cell is well above 90%. The bandgap modulated quantum well solar cell achieves 25.76% efficiency for the formation of the p-i-n region. AM1.5 G environment under 1-Sun spectrum is used to illuminate the designed solar cell.
Computational study on the effect of aspect ratio on Young’s modulus of boron nitride nanosheets
Authors: Kumari Nisha , Sarangi Saroj Kumar
Published: June 2023

The effect of the aspect ratio on Young’s modulus (E) of boron nitride nanosheets (BNNS) was evaluated using molecular dynamics simulation techniques employing the Tersoff potential field. The aspect ratio (L/B) of BNNS may influence the elastic properties; therefore, the values are varied from 2 to 12. Our results revealed that the E of BNNS decreased with an increase in the aspect ratio up to 9 and then became stable in both the armchair and zigzag directions. It is anticipated that the result will provide a beneficial understanding of the elastic properties of BNNS, which can aid in the design and implementation of structured and tailored NEMS devices, transistors, sensors, lightweight materials, and automotive sectors.
A circulant inertia three Hopfield neuron system: dynamics, offset boosting, multistability and simple microcontroller- based practical implementation
Authors: Balaraman Sundarambal , Nzoulewa Dountsop Sandrine , Kengne Jacques , Rajagopal Karthikeyan
Published: June 2023

This work investigates the dynamics and implementation of a circulant inertia three Hopefield neuron model with each neuron activated by a non-monotonic Crespi function. Owing its source to the work previously done by Song and co-authors [Song et al (2019) Mathematical Biosciences and Engineering
16. 6406–6426], we propose a network made up of three neurons connected cyclically. We demonstrate that the model is capable of the coexistence of two, three, four, six, seven, eight and ten attractors basing on different initial states. The system is dissipative and presents fifteen unstable equilibrium points for a given rank of parameters. Accordingly, we demonstrate the Hopf bifurcation in the model when the bifurcation parameter is the first synaptic weight. Moreover, using bifurcation diagrams, Maximum Lyapunov Exponent diagram, phase portraits, two parameters Lyapunov diagrams, double-sided Poincaré section and basin of attraction, intriguing phenomena have been revealed such as hysteresis, coexistence of parallel branches of bifurcation, antimonotonicity and transient chaos to name a few. A number of coexisting attractors have been developed by the new network which can be used to build sophisticated cryptosystem or to explain the possible tasks of a brain in normal or abnormal cases. To verify the feasibility of the model, a microcontroller-based implementation has been used to demonstrate the period-doubling route to chaos obtained numerically.
Investigation of energetic ion losses induced by long-lived saturated internal mode with energetic particle diagnostics in the HL-2A tokamak
Authors: Zhang Jie , Zhang Yipo , Chen Wei , Cheng Shikui , Ogawa Kunihiro , He Xiaofei , Wang Yongqin , Liu Yi , Xu Min , Isobe Mitsutaka , Zhu Yuxuan , Zhan Xuwen , Zhou Jianhang , Zhang Jinglong , Liu Liang , He Xiaoxue , Li Dong , Li Yonggao , Guo Wenping , Yu Liming , Hao Guangzhou , Li Bo , Shi Zhongbing , Ji Xiaoquan , Zhong Wulv
Published: June 2023

Several sets of energetic particle diagnostics, including a set of neutron flux monitoring systems, a solid-state neutral particle analyzer and a fast ion loss probe (FILP), have been used to investigate the energetic ion losses induced by the long-lived saturated internal mode (LLM) in the HL-2A tokamak. Clear experimental evidence for different levels of energetic ion losses induced by LLM, sawtooth and minor disruption has been observed. A numerical calculation for the evolution of neutron emissions was carried out with the FBURN code, and it shows that the neutron emission drop rate linearly increases with the LLM amplitude and no threshold perturbation amplitude exists, illustrating that the loss mechanism for LLM induced energetic ion loss is dominantly convective. In addition, measurement results of the FILP demonstrate that LLM tends to expel energetic ions with relatively low energy (

E
<
27

keV) and high pitch angle (

θ
>

60

∘

), and can suppress the prompt loss of energetic ions with high energy and low pitch angle to a certain degree. Furthermore, the physical process for LLM induced energetic ion loss can be explained by orbit calculations, which show that LLM induced lost energetic ions will transport from center to peripheral region first, and then get lost out of plasma. The experimental observations are successfully reproduced by calculations using the ORBIT code combined with both the NUBEAM code and the MARS-K code. The paper clearly describes the whole physical process of LLM induced energetic ion loss for the first time in the HL-2A tokamak.