bluuebunny/crossref_metadata_2025 huggingface dataset:
Mesoscale Structures in Earth's Magnetotail Observed Using Energetic Neutral Atom Imaging
Authors: Keesee A. M. , Buzulukova N. , Mouikis C. , Scime E. E.
Published: December 2020

Mesoscale structures in Earth's magnetotail are a primary feature of particle transport to the inner magnetosphere during storms and substorms. We demonstrate that such structures can be observed in energetic neutral atom (ENA) data which can provide remote, global images of the magnetosphere. In particular, we present localized regions of increased ion temperatures that appear in equatorial ion temperature maps calculated from Two Wide‐angle Imaging Neutral‐atom Spectrometers (TWINS) ENA data. These regions are associated with a dipolarization front with bursty ion flows measured by Magnetospheric MultiScale (MMS) and are concurrent with substorm features observed in field aligned currents (FAC) from Active Magnetosphere and Planetary Electrodynamics Response Experiment measurements. We conduct a magnetohydrodynamics simulation of the same event and show simulated ion temperatures, ion flows, and FACs that agree with the measurements. However, the observed plasma heating is less intense in the simulated results than in the TWINS and MMS data, indicating that some heating processes may be missing from the model.
Evidence for Nonadiabatic Oxygen Energization in the Near‐Earth Magnetotail From MMS
Authors: Bingham S. T. , Nikoukar R. , Cohen I. J. , Mauk B. H. , Turner D. L. , Mitchell D. G. , Burch J. L. , Gomez R. G. , Fuselier S. A. , Torbert R. B.
Published: December 2020

We present Magnetospheric Multiscale (MMS) mission observations of substorm‐related ion injections at magnetotail positions between ∼7.5 RE and 8.5 RE. Energization of supra‐thermal ions (50 keV–1,000 keV) is strongly species dependent, with oxygen reaching significantly higher peak energies than protons. Using a previously established correlation technique, we confirm that the highest energy (>400 keV) oxygen ions are multiply charged of solar wind origin, enabling them to reach high energies in rough proportion to their charge states. Significantly, we conclude that oxygen ions between 130 keV and 330 keV are singly charged, and that they sometimes achieve higher energizations relative to protons, that is, higher than expected based on their charge states. We conclude that nonadiabatic processes can boost the energies of the oxygen ions. The technique does not depend on “before injection” and “after injection” spectral comparisons, and therefore likely represents the most definitive test yet of nonadiabaticity.
Complexity of Mesoscale Eddy Diffusivity in the Ocean
Authors: Kamenkovich Igor , Berloff Pavel , Haigh Michael , Sun Luolin , Lu Yueyang
Published: December 2020

Stirring of water by mesoscale currents (“eddies”) leads to large‐scale transport of many important oceanic properties (“tracers”). These eddy‐induced transports can be related to the large‐scale tracer gradients, using the concept of turbulent diffusion. The concept is widely used to describe these transports in the real ocean and to represent them in climate models. This study focuses on the inherent complexity of the corresponding coefficient tensor (“K‐tensor”) and its components, defined here in all its spatio‐temporal complexity. Results demonstrate that this comprehensive K‐tensor is space‐, time‐, direction‐ and tracer‐dependent. Using numerical simulations with both idealized and comprehensive models of the Atlantic circulation, we show that these properties lead to upgradient eddy fluxes and the potential importance of all tensor components. The uncovered complexity of the eddy transports calls for reconsideration of how they are estimated in practice, included in the general circulation models and theoretically interpreted.
A Numerical Study of Onshore Ripple Migration Using a Eulerian Two‐phase Model
Authors: Salimi‐Tarazouj Ali , Hsu Tian‐Jian , Traykovski Peter , Cheng Zhen , Chauchat Julien
Published: December 2020

A new modeling methodology for ripple dynamics driven by oscillatory flows using a Eulerian two‐phase flow approach is presented in order to bridge the research gap between near‐bed sediment transport via ripple migration and suspended load transport dictated by ripple induced vortices. Reynolds‐averaged Eulerian two‐phase equations for fluid phase and sediment phase are solved in a two‐dimensional vertical domain with a k‐ε closure for flow turbulence and particle stresses closures for short‐lived collision and enduring contact. The model can resolve full profiles of sediment transport without making conventional near‐bed load and suspended load assumptions. The model is validated with an oscillating tunnel experiment of orbital ripple driven by a Stokes second‐order (onshore velocity skewed) oscillatory flow with a good agreement in the flow velocity and sediment concentration. Although the suspended sediment concentration far from the ripple in the dilute region was underpredicted by the present model, the model predicts an onshore ripple migration rate that is in very good agreement with the measured value. Another orbital ripple case driven by symmetric sinusoidal oscillatory flow is also conducted to contrast the effect of velocity skewness. The model is able to capture a net offshore‐directed suspended load transport flux due to the asymmetric primary vortex consistent with laboratory observation. More importantly, the model can resolve the asymmetry of onshore‐directed near‐bed sediment flux associated with more intense boundary layer flow speed‐up during onshore flow cycle and sediment avalanching near the lee ripple flank which force the onshore ripple migration.
Potential and Challenges of Investigating Intrinsic Uncertainty of Hydrological Models With Stochastic, Time‐Dependent Parameters
Authors: Reichert Peter , Ammann Lorenz , Fenicia Fabrizio
Published: December 2020

Stochastic hydrological process models have two conceptual advantages over deterministic models. First, even though water flow in a well‐defined environment is governed by deterministic differential equations, a hydrological system, at the level we can observe it, does not behave deterministically. Reasons for this behavior are unobserved spatial heterogeneity and fluctuations of input, unobserved influence factors, heterogeneity and variability in soil and aquifer properties, and an imprecisely known initial state. A stochastic model provides thus a more realistic description of the system than a deterministic model. Second, hydrological models simplify real processes. The resulting structural deficits can better be accounted for by stochastic than by deterministic models because they, even for given parameters and input, allow for a probability distribution of different system evolutions rather than a single trajectory. On the other hand, stochastic process models are more susceptible to identifiability problems and Bayesian inference is computationally much more demanding. In this paper, we review the use of stochastic, time‐dependent parameters to make deterministic models stochastic, discuss options for the numerical implementation of Bayesian inference, and investigate the potential and challenges of this approach with a case study. We demonstrate how model deficits can be identified and reduced, and how the suggested approach leads to a more realistic description of the uncertainty of internal and output variables of the model compared to a deterministic model. In addition, multiple stochastic parameters with different correlation times could explain the variability in the time scale of output error fluctuations identified in an earlier study.
Distinguishing intrinsic photon correlations from external noise with frequency-resolved homodyne detection
Authors: Lüders Carolin , Aßmann Marc
Published: December 2020

In this work, we apply homodyne detection to investigate the frequency-resolved photon statistics of a cw light field emitted by a driven-dissipative semiconductor system in real time. We demonstrate that studying the frequency dependence of the photon number noise allows us to distinguish intrinsic noise properties of the emitter from external noise sources such as mechanical noise while maintaining a sub-picosecond temporal resolution. We further show that performing postselection on the recorded data opens up the possibility to study rare events in the dynamics of the emitter. By doing so, we demonstrate that in rare instances, additional external noise may actually result in reduced photon number noise in the emission.
Environmental patterns of brown moss- and Sphagnum-associated microbial communities
Authors: Tveit Alexander Tøsdal , Kiss Andrea , Winkel Matthias , Horn Fabian , Hájek Tomáš , Svenning Mette Marianne , Wagner Dirk , Liebner Susanne
Published: December 2020

Northern peatlands typically develop through succession from fens dominated by the moss family Amblystegiaceae to bogs dominated by the moss genusSphagnum. How the different plants and abiotic environmental conditions provided in Amblystegiaceae andSphagnumpeat shape the respective moss associated microbial communities is unknown. Through a large-scale molecular and biogeochemical study spanning Arctic, sub-Arctic and temperate regions we assessed how the endo- and epiphytic microbial communities of natural northern peatland mosses relate to peatland type (Sphagnumand Amblystegiaceae), location, moss taxa and abiotic environmental variables. Microbial diversity and community structure were distinctly different between Amblystegiaceae andSphagnumpeatlands, and within each of these two peatland types moss taxon explained the largest part of microbial community variation.Sphagnumand Amblystegiaceae shared few (< 1% of all operational taxonomic units (OTUs)) but strikingly abundant (up to 65% of relative abundance) OTUs. This core community overlapped by one third with theSphagnum-specific core-community. Thus, the most abundant microorganisms inSphagnumthat are also found in all theSphagnumplants studied, are the same OTUs as those few shared with Amblystegiaceae. Finally, we could confirm that these highly abundant OTUs were endophytes inSphagnum, but epiphytes on Amblystegiaceae. We conclude that moss taxa and abiotic environmental variables associate with particular microbial communities. While moss taxon was the most influential parameter, hydrology, pH and temperature also had significant effects on the microbial communities. A small though highly abundant core community is shared betweenSphagnumand Amblystegiaceae.
Associating Emergency Medical Services personnel’s workload, trauma exposure, and health with the cortisol, endocannabinoid, and N-acylethanolamine concentrations in their hair
Authors: Behnke Alexander , Karabatsiakis Alexander , Krumbholz Aniko , Karrasch Sarah , Schelling Gustav , Kolassa Iris-Tatjana , Rojas Roberto
Published: December 2020

In their line of duty, Emergency Medical Services (EMS) personnel are exposed to chronically stressful working conditions and recurrent traumatic events, which increase their risk for detrimental health outcomes. Here, we investigated whether this risk is due to altered regulation of the hypothalamus–pituitary–adrenal (HPA) axis and the endocannabinoid system. Therefore, 1 cm hair strands were collected from a cohort of 72 German EMS personnel in order to measure concentrations of cortisol, endocannabinoids [i.e., anandamide (AEA), 2-arachidonoylglycerol (2-AG)], and N-acylethanolamines [i.e., stearoylethanolamide (SEA), oleoylethanolamide (OEA), and palmitoylethanolamide (PEA)]. Rank correlation analyses were conducted to test associations of cortisol, endocannabinoid, and N-acylethanolamine concentrations with the EMS personnel’s workload, lifetime trauma exposure, and mental and physical health problems. We found a negative correlation between cortisol and 2-AG concentrations in hair. Higher hair cortisol was associated with higher workload. Reported traumatic stress during childhood and later in life as well as more severe depressive and physical stress symptoms were associated with elevated 2-AG, SEA, OEA, and PEA concentrations. Future longitudinal research needs to address the prospect of tracing biomolecular markers of glucocorticoid, endocannabinoid, and N-acylethanolamine activity as a predicting value of the long-term course of mental and physical well-being.
An optimised MALDI-TOF assay for phosphatidylcholine-specific phospholipase C
Authors: Sharma Nabangshu , Langley Ries J. , Eurtivong Chatchakorn , Leung Euphemia , Dixon Ryan Joseph , Paulin Emily K. , Rees Shaun W. P. , Pilkington Lisa I. , Barker David , Reynisson Jóhannes , Leung Ivanhoe K. H.
Published: December 2020

In this manuscript, we report our work in the development and optimisation of a MALDI-TOF mass spectrometry assay to monitor the kinetics and inhibition of PC-PLC, a phospholipase that catalyses the hydrolysis of phosphatidylcholines.
B-Doped core–shell Fe@BC nanozymes: active site identification and bacterial inhibition
Authors: Jiang Xingxing , Liu Kang , Li Qiang , Liu Min , Yang Minghui , Chen Xiang
Published: December 2020

A B-doped core–shell Fe@BC peroxidase mimic was rationally designed using an optimal BCO2 active site for bacterial inhibition.
Organophosphate flame retardants and diesters in the urine of e-waste dismantling workers: associations with indoor dust and implications for urinary biomonitoring
Authors: Qin Rui-Xin , Tang Bin , Zhuang Xi , Lei Wei-Xiang , Wang Mei-Huan , Zhang Luo-Hong , Hu Ke-Mei
Published: December 2020

Indoor dust ingestion is one of the main pathways for human exposure to organophosphate flame retardants (PFRs).
Development and experimental evaluation of a mathematical model to predict polymer-enhanced nanoparticle mobility in heterogeneous formations
Authors: Mohammadnejad Hamed , Marion Bonnie A. , Kmetz Anthony A. , Johnson Keith P. , Pennell Kurt D. , Abriola Linda M.
Published: December 2020

A mathematical model is developed and evaluated for polymer-facilitated nanoparticle transport. Results demonstrate that the model can reproduce experimental observations of nanoparticle migration and attachment in a heterogeneous packed flow cell.
Low concentrations of Cu2+ in synthetic nutrient containing wastewater inhibit MgCO3-to-struvite transformation
Authors: Barčauskaitė Karolina , Drapanauskaitė Donata , Silva Manoj , Murzin Vadim , Doyeni Modupe , Urbonavicius Marius , Williams Clinton F. , Supronienė Skaidrė , Baltrusaitis Jonas
Published: December 2020

Magnesite has been used to produce struvite from nutrient rich wastewater in the presence of Cu2+ and Zn2+, and the effects of this fertilizer material on soil microflora have been reported.
Boron carbonitride with tunable B/N Lewis acid/base sites for enhanced electrocatalytic overall water splitting
Authors: Shi Dong , Chang Bin , Ai Zizheng , Jiang Hehe , Chen Fuzhou , Shao Yongliang , Shen Jianxing , Wu Yongzhong , Hao Xiaopeng
Published: December 2020

Lewis acid–base theory and DFT results showed that different enrichment degrees of B and N elements in BCN can improve the adsorption energy of OH*/H2O. BCN exhibits optimum electrocatalytic overall water splitting performance after adjustments.
Three-dimensional atomic structure of supported Au nanoparticles at high temperature
Authors: Liu Pei , Arslan Irmak Ece , De Backer Annick , De wael Annelies , Lobato Ivan , Béché Armand , Van Aert Sandra , Bals Sara
Published: December 2020

The 3D atomic structure of supported Au nanoparticles is characterized as a function of temperature and their dynamic structural evolution at elevated temperatures is investigated by using HAADF-STEM images acquired along a single viewing direction.
Origins of pressure-induced enhancement in thermal conductivity of hybrid inorganic–organic perovskites
Authors: Giri Ashutosh
Published: December 2020

The thermal conductivity of hybrid perovskites can be tuned by more than an order of magnitude through application of hydrostatic pressure, thus emphasizing the potential in enhancing their efficiencies in photovoltaic applications.
Effect of backbone and end-group regioisomerism on thermomechanical properties of vanillin-based polyurethane networks
Authors: Rangamani Adithya , Alabi Christopher A.
Published: December 2020

Monomer composition, geometry, cross-link density, and cross-link distribution are the primary determinants of material properties in thermosetting networks.
Observing the three-dimensional dynamics of supported metal complexes
Authors: Paterson Alexander L. , Liu Da-Jiang , Kanbur Uddhav , Sadow Aaron D. , Perras Frédéric A.
Published: December 2020

The dynamics of heterogeneous catalysts are linked to their activity and selectivity but are poorly understood. NMR enables for the determination of high-resolution dynamic structures for such sites and the mapping of accessible conformations.
Identification of the peptide epimerase MslH responsible for d-amino acid introduction at the C-terminus of ribosomal peptides
Authors: Feng Zhi , Ogasawara Yasushi , Dairi Tohru
Published: December 2020

The biosynthesis of d-tryptophan containing lasso peptide MS-271 involves the epimerization of a ribosomal peptide MslA catalyzed by a novel class of metal- and cofactor-independent peptide epimerase MslH.
Enabling high-performance room-temperature sodium/sulfur batteries with few-layer 2H-MoSe2embellished nitrogen-doped hollow carbon spheres as polysulfide barriers
Authors: Dong Chunwei , Zhou Hongyu , Jin Bo , Gao Wang , Lang Xingyou , Li Jianchen , Jiang Qing
Published: December 2020

A novel functional separator is designed and prepared for high-performance RT-Na/S batteries, in which 2H-MoSe2/N-HCS is used as not only the key component of the modified separator but also the sulfur host.
Utilization of electron-beam irradiation under atomic-scale chemical mapping for evaluating the cycling performance of lithium transition metal oxide cathodes
Authors: Shim Jae-Hyun , Kang Hyosik , Lee Sanghun , Kim Young-Min
Published: December 2020

A true chemical information of Ni-rich cathode materials at the atomic scale was obtained.
Oxygen defect-stabilized heterogeneous single atom catalysts: preparation, properties and catalytic application
Authors: Zhang Lei , Zhao Xiufei , Yuan Zhengqiu , Wu Ming , Zhou Hu
Published: December 2020

In this review, the effect of oxygen vacancies on SAC stabilization is summarized and recent applications in molecular catalysis are discussed in detail.
Multi‐scene upgrade and renovation method of existing park‐level integrated energy system based on comprehensive analysis
Authors: Cao Yan , Mu Yunfei , Jia Hongjie , Qi Yan , Wang Congshan
Published: December 2020

Some of the existing park‐level integrated energy systems (PIESs) experience problems such as mismatch between energy supply and demand, high operation costs, and low renewable energy consumption capacity. To improve the energy supply level of the existing PIES, the multi‐scene upgrade and renovation method of the existing PIES based on comprehensive analysis is proposed. First, the physical model of the existing PIES for renovation is constructed, including expansion of existing equipment and newly added candidate equipment. Second, to determine the deficiencies, the current situation of the existing PIES is analysed based on the planning and operation data as well as indexes including economy, photovoltaic consumption capacity, and so on. On this basis, multiple renovation scenes are set up, and the upgrade and renovation model is constructed, assuming minimal investment, operation, and maintenance costs to be the objective function. Thereafter, the equipment allocation scheme of each scene is solved, for which comprehensive evaluation is performed. Finally, considering an existing PIES as an example, the weak energy storage and heating links are upgraded and renovated, effectively improving the performance of the existing PIES in reducing costs and carbon emissions, and improving energy utilisation efficiency.
Data‐driven transient frequency stability assessment: A deep learning method with combined estimation‐correction framework
Authors: Wen Yunfeng , Zhao Rongzhen , Huang Mingzeng , Guo Chuangxin
Published: December 2020

Transient frequency stability assessment (TFSA) is important for operators to understand dynamic power system frequency characteristics. However, because of the problem of combinatorial explosion, exacerbated by uncertain renewable generation and various contingencies, applying traditional time‐domain simulation methods is very time‐consuming for TFSA of a low‐inertia power system. To address this, this study evaluates a fast and online TFSA using a data‐driven tool, based on deep learning. A novel combined estimation–correction learning framework is proposed. In the estimation step, a deep neural network is used to obtain the network parameters based on actual input–output feature data, which effectively realize automatic dimension reduction and feature extraction. In the subsequent correction step, the multidimensional frequency metrics produced by the deep neural network‐based estimator are input to a stacked extreme learning machine‐based corrector to further reduce the prediction error. A case study on a modified IEEE RTS‐79 system demonstrates that the proposed approach has extremely high computation speed, compared to the time‐domain simulation method, and achieves higher prediction accuracy and superior generalisation performance in comparison with other state‐of‐the‐art algorithms.
Deterministic proxies for stochastic unit commitment during hurricanes
Authors: Mohammadi Farshad , Jafarishiadeh Fatemehalsadat , Xue Jiayue , Sahraei‐Ardakani Mostafa , Ou Ge
Published: December 2020

Severe weather threatens the reliability of the power supply by damaging the network. In the case of hurricanes, tens of elements may fail, which would lead to power outages. Under such circumstances, preventive unit commitment methods can model the probabilistic failure forecasts and minimise the power outages. Preventive stochastic unit commitment is an effective method to consider failure forecasts to reduce the power outage. Although stochastic unit commitment produces high‐quality solutions, it is computationally burdensome. Thus, this paper evaluates proxy deterministic methods with lighter computational compared with stochastic unit commitment on both the solution time and quality. Adjusted spinning reserve requirements, engineering judgment‐based rules, and robust preventive operation are among the evaluated methods. Numerical results are obtained for the synthetic grid on the footprint of Texas with 2000 buses. The results suggest that while some proxy methods, such as standard spinning‐reserve and adjusted spinning‐reserve with 6% to 30% of the spinning capacity, may not be as effective as the stochastic method, others, such as robust optimisation, deliver the majority of the stochastic benefits with substantially less (85%) computational time. Monte Carlo simulations are used to evaluate the quality of solutions in reducing the expected unserved load and over‐generation.
Selective focus saliency model driven by object class‐awareness
Authors: Zhao Danpei , Yuan Bo , Shi Zhenwei , Jiang Zhiguo
Published: December 2020

Current many salient object detection (SOD) models only focus on highlighting visual conspicuous region but fail to make saliency detection for specific targets. In this paper, a selective focus saliency model driven by object class‐awareness (SF‐OCA) to run saliency detection is proposed. The framework consists of a visual saliency detection flow, a segmentation‐classification flow, and a class‐awareness selection module. It combines bottom‐up visual perception with a top‐down task‐driven manner, which is capable of detecting specific category salient targets and eliminating the interference from other saliency areas, providing a new idea for saliency detection. Experimental results show that the method achieves comparable performance with state‐of‐the‐art models on four public saliency datasets. In addition, a new dataset was also built to test the proposed framework for the selective focus saliency detection. Compared with other SOD methods, the method not only highlights visual saliency regions but can choose more important or more noteworthy targets in a class‐awareness manner. The method also shows better robustness under a variety of conditions including multi‐targets, small targets and complex background.
An eight‐switch five‐level inverter with zero leakage current
Authors: Kumari Sangeeta , Verma Arun Kumar , N Sandeep , Yaragatti Udaykumar R. , Pota Hemanshu Roy
Published: December 2020

This paper examines a multilevel transformer‐less grid‐tied inverter topology is proposed for PV applications. Nowadays, transformer‐less inverters are more desirous due to their small filter size, cheaper and higher efficiency. However, the removal of transformer results in the existence of leakage current due to absence of galvanic isolation. The flow of leakage current is the cause of personal safety and deteriorating power quality. A transformer‐less inverter topology is proposed which is able to solve the leakage current issue. Besides, it has the ability to generate the boosted voltage without the need of magnetic component or boosting circuit. It works on the principle of flying/switched capacitor which are able to naturally balance the voltage. Hence, it does not have the limitation of modulation index and no need of complex control scheme to balance or regulate the voltage across an auxiliary capacitor. The performance of the proposed topology is verified by implementing a laboratory prototype which validates the operation and performance of the proposed topology. Results depicting the output voltage, load current and voltage across the auxiliary capacitor are presented for various operating conditions. Moreover, a comprehensive comparison is done, in terms of component count, level and boosting ability of output voltage with leakage current condition.
Is Appropriate Administration of Antenatal Corticosteroids Associated with Maternal Race?
Authors: Ondusko Devlynne S. , Garg Bharti , Caughey Aaron B. , Pilliod Rachel A. , Carter Emily H.
Published: December 2020

Objective Antenatal corticosteroids (ACSs) improve outcomes for premature infants; however, not all pregnant women at risk for preterm delivery receive ACS. Racial minorities are less likely to receive adequate prenatal care and more likely to deliver preterm. The objective of this study was to determine if maternal race is associated with a lower rate of ACS administration in Washington for women at risk of preterm labor (between 23 and 34 weeks).

Study Design This was a population-based retrospective cohort study of singleton, nonanomalous, premature deliveries in Washington state between 2007 and 2014. Descriptive data included maternal sociodemographics, pregnancy complications, facility of birth, and neonatal characteristics. The primary outcome was maternal receipt of ACS and the independent variable was maternal race/ethnicity. The secondary outcomes included neonatal need for assisted ventilation, both initially and for more than 6 hours, and administration of surfactant. Data were analyzed using chi-square tests and logistic regression models.

Results A total of 8,530 nonanomalous, singleton neonates were born between 23 and 34 weeks' gestation. Of those, 55.8% of mothers were self-identified as white, 7.5% as black, 21.4% as Hispanic, 10.9% as Asian, and 4.3% as Native American. After adjusting for confounders, black woman–neonate dyads had significantly lower odds of receiving ACS, (adjusted odds ratio [aOR] = 0.62; 95% confidence interval [CI]: 0.51–0.76), assisted ventilation immediately following delivery (aOR = 0.76; 95% CI: 0.61–0.94) and for more than 6 hours (aOR = 0.64; 95% CI: 0.49–0.84) and surfactant therapy (aOR = 0.62; 95% CI: 0.42–0.92) as compared with whites.

Conclusion These findings contribute to the current body of literature by describing racial disparities in ACS administration for pregnant women at risk for preterm delivery. To better understand the association between black race and administration of ACS, future studies should focus on differences within and between hospitals (including quality, location, resources), patient health literacy, social determinants of health, and exposure to systemic racism and discrimination.

Key Points
Airborne drying of respiratory droplets exposes fewer viral particles than on surfaces
Authors: Ishimaru Matthew
Published: December 2020

Researchers use acoustic levitation to study midair evaporation and desiccation of COVID-19 respiratory droplets.
Performance limits of reservoir computers at the edge of chaos
Authors: Ishimaru Matthew
Published: December 2020

Research shows that dynamic effects caused by approaching chaos sometimes degrade overall performance.
Microrheology for biomaterial design
Authors: Joyner Katherine , Yang Sydney , Duncan Gregg A.
Published: December 2020

Microrheology analyzes the microscopic behavior of complex materials by measuring the diffusion and transport of embedded particle probes. This experimental method can provide valuable insight into the design of biomaterials with the ability to connect material properties and biological responses to polymer-scale dynamics and interactions. In this review, we discuss how microrheology can be harnessed as a characterization method complementary to standard techniques in biomaterial design. We begin by introducing the core principles and instruments used to perform microrheology. We then review previous studies that incorporate microrheology in their design process and highlight biomedical applications that have been supported by this approach. Overall, this review provides rationale and practical guidance for the utilization of microrheological analysis to engineer novel biomaterials.
Phase-field-crystal description of active crystallites: Elastic and inelastic collisions
Authors: Ophaus Lukas , Kirchner Johannes , Gurevich Svetlana V. , Thiele Uwe
Published: December 2020

The active Phase-Field-Crystal (aPFC) model combines elements of the Toner–Tu theory for self-propelled particles and the classical Phase-Field-Crystal (PFC) model that describes the transition between liquid and crystalline phases. In the liquid-crystal coexistence region of the PFC model, crystalline clusters exist in the form of localized states that coexist with a homogeneous background. At sufficiently strong activity (related to self-propulsion strength), they start to travel. We employ numerical path continuation and direct time simulations to first investigate the existence regions of different types of localized states in one spatial dimension. The results are summarized in morphological phase diagrams in the parameter plane spanned by activity and mean density. Then we focus on the interaction of traveling localized states, studying their collision behavior. As a result, we distinguish “elastic” and “inelastic” collisions. In the former, localized states recover their properties after a collision, while in the latter, they may completely or partially annihilate, forming resting bound states or various traveling states.
Self-radiography of imploded shells on OMEGA based on additive-free multi-monochromatic continuum spectral analysis
Authors: Epstein R. , Mancini R. C. , Cliche D. T. , Shah R. C. , Collins T. J. B. , Stoeckl C. , McKenty P. W. , Radha P. B. , Regan S. P. , Goncharov V. N.
Published: December 2020

Radiographs of pure-DT cryogenic imploding shells provide critical validation of progress toward ignition-scalable performance of inertial confinement fusion implosions [J. Nuckolls et al., Nature 239, 139 (1972)]. Cryogenic implosions on the OMEGA Laser System [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] can be self-radiographed by their own core spectral emission near ≈2 keV. Utilizing the distinct spectral dependences of continuum emissivity and opacity, the projected optical-thickness distribution of imploded shells, i.e., the shell radiograph, can be distinguished from the structure of the core emission distribution in images. Importantly, this can be done without relying on spectral additives (shell dopants), as in previous applications of implosion self-radiography [V. A. Smalyuk et al., Phys. Rev. Lett. 87, 155002 (2001); L. A. Pickworth et al., ibid. 117, 035001 (2016)]. Demonstrations with simulated data show that this technique is remarkably well-suited to cryogenic implosions and can also be applied to self-radiography of imploded room-temperature CH shells at higher spectral energy (hv ≈ 3–5 keV) based on the very similar continuum spectrum of carbon. Experimental demonstration of additive-free self-radiography with warm CH shell implosions on OMEGA will provide an important proof of principle for future applications to cryogenic DT implosions.
High-resolution measurement of atomic force microscope cantilever resonance frequency
Authors: Xu Bowen , Saygin Verda , Brown Keith A. , Andersson Sean B.
Published: December 2020

The atomic force microscope (AFM) is widely used in a wide range of applications due to its high scanning resolution and diverse scanning modes. In many applications, there is a need for accurate and precise measurement of the vibrational resonance frequency of a cantilever. These frequency shifts can be related to changes in mass of the cantilever arising from, e.g., loss of fluid due to a nanolithography operation. A common method of measuring resonance frequency examines the power spectral density of the free random motion of the cantilever, commonly known as a thermal. While the thermal is capable of reasonable measurement resolution and speed, some applications are sensitive to changes in the resonance frequency of the cantilever, which are small, rapid, or both, and the performance of the thermal does not offer sufficient resolution in frequency or in time. In this work, we describe a method based on a narrow-range frequency sweep to measure the resonance frequency of a vibrational mode of an AFM cantilever and demonstrate it by monitoring the evaporation of glycerol from a cantilever. It can be seamlessly integrated into many commercial AFMs without additional hardware modifications and adapts to cantilevers with a wide range of resonance frequencies. Furthermore, this method can rapidly detect small changes in resonance frequency (with our experiments showing a resolution of ∼0.1 Hz for cantilever resonances ranging from 70 kHz to 300 kHz) at a rate far faster than with a thermal. These attributes are particularly beneficial for techniques such as dip-pen nanolithography.
Quantifying non-centrosymmetric orthorhombic phase fraction in 10 nm ferroelectric Hf0.5Zr0.5O2 films
Authors: Mukundan Vineetha , Consiglio Steven , Triyoso Dina H. , Tapily Kandabara , Schujman Sandra , Mart Clemens , Kämpfe Thomas , Weinreich Wenke , Jordan-Sweet Jean , Clark Robert D. , Leusink Gert J. , Diebold Alain C.
Published: December 2020

In this Letter, we report the percentage of the ferroelectric phase in a 10-nm-thick Hf0.5Zr0.5O2 (HZO) film deposited in a metal-insulator-metal stack by atomic layer deposition. The ferroelectric behavior was confirmed by polarization measurements and piezoresponse force microscopy. Ferroelectric behavior in this material has been attributed most likely to the formation of the polar non-centrosymmetric orthorhombic phase [Müller et al., Appl. Phys. Lett. 99, 102903 (2011)], which is difficult to distinguish from the tetragonal phase in x-ray diffraction due to peak overlap. Using a model for each of the crystal phases of hafnia-zirconia, the phase percentages were estimated using a Rietveld refinement method applied to grazing incidence x-ray diffraction data and a linear combination fit analysis procedure [McBriarty et al., Phys. Status Solidi 257, 1900285 (2020)] applied to grazing incidence extended x-ray absorption fine structure data. Using these methods, it was found that the tetragonal (P42/nmc) phase is the most prevalent at 48–60% followed by the polar non-centrosymmetric orthorhombic (Pca21) phase at 35%–40% with the remainder consisting of the monoclinic (P21/c) phase. Understanding the details of the effect of the phase structure on the electrical properties of these materials is extremely important for device engineering of HZO for logic and emerging nonvolatile memory applications.
A microstructure model for viscoelastic–thixotropic fluids
Authors: Le-Cao K. , Phan-Thien N. , Mai-Duy N. , Ooi S. K. , Lee A. C. , Khoo B. C.
Published: December 2020

A microstructure model to describe the viscoelasticity and thixotropy properties of complex fluids is proposed. The model is based on the Lodge–Yamamoto network theory and is an extension of the Phan-Thien–Tanner model, with a kinetic process in which specific forms of creation and destruction rates are assumed. The final equation is simple with a small number of empirical parameters required and can be conveniently employed in engineering simulations. The predictions based on the model in a variety of shear and oscillatory shear flows are given. The stress response obtained from the model prediction agrees well with experiments on both shear and oscillatory flow histories.
Altered Cl
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homeostasis hinders forebrain GABAergic interneuron migration in a mouse model of intellectual disability
Authors: Maset Andrea , Galla Luisa , Francia Simona , Cozzolino Olga , Capasso Paola , Goisis Rosa Chiara , Losi Gabriele , Lombardo Angelo , Ratto Gian Michele , Lodovichi Claudia
Published: December 2020

Significance

Intellectual disability associated with Oligophrenin 1 (OPHN1) mutation is a neurodevelopmental disorder characterized by a wide range of cognitive and social dysfunction. Here, we dissected the impact of OPHN1 mutation on the postnatal migration of inhibitory interneurons, a process that is thought to play a key role in postnatal developmental plasticity. We found that loss of function of OPHN1 led to an early maturation of the morphofunctional properties of the neuronal precursors that impaired their migration and resulted in a dramatically lower number of cells reaching their target area. We identified pharmacological treatments able to rescue the abnormal development of neuronal precursors and their migration.
Selective Aster inhibitors distinguish vesicular and nonvesicular sterol transport mechanisms
Authors: Xiao Xu , Kim Youngjae , Romartinez-Alonso Beatriz , Sirvydis Kristupas , Ory Daniel S. , Schwabe John W. R. , Jung Michael E. , Tontonoz Peter
Published: December 2020

Significance

The Aster proteins are transporters that move cholesterol between the plasma membrane and the ER. Here, we develop and characterize small molecules that selectively inhibit one or more Aster proteins. Importantly, we identify compounds that block Aster-mediated cholesterol transport without interfering with other sterol regulatory proteins, including NPC1 and SREBP2. Cell studies reveal that inhibition of Aster function by small molecules blocks the movement of LDL-derived cholesterol from the plasma membrane to the ER, thus positioning the nonvesicular Aster pathway downstream of the NPC1 vesicular pathway in the movement of LDL-derived cholesterol.
The Duhumbi perspective on Proto-Western Kho-Bwa onsets
Authors: Bodt Timotheus Adrianus
Published: December 2020

The eight Western Kho-Bwa varieties are spoken in western Arunachal Pradesh in Northeast India and form a small, coherent
sub-group of the Tibeto-Burman (Trans-Himalayan / Sino-Tibetan) language family.

This paper presents 96 sound correspondences, mainly between the two Western Kho-Bwa varieties Duhumbi and Khoitam, with
additional evidence from other Western Kho-Bwa varieties and other Tibeto-Burman languages whenever deemed illustrative. On basis of these
sound correspondences, I propose 282 Western Kho-Bwa proto-forms including a total of 92 onsets. The less common reconstructed Western
Kho-Bwa onsets are the uvular onsets and the voiceless nasal and approximant onsets.

A unique innovation of the Western Kho-Bwa languages, and indeed the Kho-Bwa languages in general, is the correspondence
of initial *s- in other Tibeto-Burman languages to a vocal onset in Proto-Western Kho-Bwa and its descendent varieties. Another relatively
unique innovation is the correspondence between Western Kho-Bwa obstruent onsets *b- and *g- ~ *kʰ- ~ *k- and other Tibeto-Burman nasal
onsets *m- and *ŋ-, respectively.
Methodology for building the optimal test bench of software and hardware complexes of control systems
Authors: Zhuravlev A V , Aksyonov K A , Knyazev R O
Published: December 2020

The paper considers the issue of creating unified approaches to building test stands for software and hardware control systems. A universal architecture of the test bench is proposed and the author’s method of constructing optimal test stands, obtained as a result of research in the field of complex automation of the test process, is described. The algorithm of directed search for the best test stand configuration is considered by example and the results of the implementation of the proposed method are demonstrated.
Analysis of the methods for accounting the renewable and non-renewable resources in scheduling
Authors: Antonova A S , Aksyonov K A
Published: December 2020

The paper discusses a scheduling problem taking into account the constraints on the renewable and non-renewable resources and availability of the works due dates. For the problem, an overview of the scheduling methods is given. The considered scheduling methods include approximate optimization algorithms and hybrid algorithms based on the genetic algorithm. It is concluded that it is necessary to use heuristic methods to find a solution. A new hybrid scheduling method based on multi-agent simulation is proposed. Application of agent-based simulation allows one to take into account the life cycle of the non-renewable resources and to distribute the renewable resources during scheduling. The genetic algorithm ensures search for the effective schedule with aim at the minimum cost of attracting the additional renewable resources in order to maintain the works deadlines.
Software Development Life Cycle early phases and quality metrics: A Systematic Literature Review
Authors: Ergasheva Shokhista , Kruglov Artem
Published: December 2020

Most of the currently used software development metrics are concentrated on the latter stages like development and testing. However, early revealing of errors during the SDLC(Software Development Life Cycle) tremendously affects the efficiency of the team work by spending more time on prevention and less on correction in later stages.

Furthermore, reworking in later stages increase the cost of quality, lead to extra waste of time of the development team. The objective of this review is to examine the classification of the existing SDLC(Software Development Life Cycle) early phases and define the set of software process quality metrics. Based on the SRL research protocol, we selected the most relevant studies from overall 200 publications by the use of search keywords and inclusion/exclusion criteria for quality assessment of primary studies. This systematic literature review yields the correlation of cost, time and software product quality with the SDLC stages.
Development of cluster models for municipal educational institutions of Tomsk region
Authors: Kvasnikova I K , Lepustin A V , Katsman Yu Ya , Lepustina E V
Published: December 2020

This paper describes the cluster models construction for schools in the Tomsk region. K-means method is used to distribute objects between clusters using the multidimensional vector of variables (socio-economic status of students, qualification and age of teaching staff, students’ participation in academic competitions, students in difficult living conditions, etc.). The cluster models were constructed for urban schools (regional center), country and ungraded schools. The computer simulation using STATISTICA system was performed due to large amount of source data and complexity of the developed models. The analysis showed the relationship between the values of cluster variables and the results of Unified State Exams (USE).
Application of multi-agent approach in the electric power control systems within the active energy complex
Authors: Zhavoronkov A E , Aksyonova O P
Published: December 2020

This paper provides an analytical overview of artificial intelligence technologies used in the tasks of technological management of the electric power industry. The relevance of using multi-agent systems is proved for solving energy problems. The concept of an intelligent energy system is considered with an active adaptive network (IES AAN). A block diagram of the electric power system management system is given within the IES AAN. It is shown that the developed centralized management principles are not fully applicable for small distribution networks – microgrid, with the use of storage devices and renewable sources. The article describes the active energy complex in Russia in the context of an analog of the Microgrid concept. The required functionality of a intelligent controllable connection (ICC) is studied, the main algorithm of the ICC operation is given, and the proposed structure is described for building a distributed system of intelligent multi-agent control of the AEC that implements the required functions.
Single-phase ion trap with cylindrical zero-potential surface
Authors: Kosternoi I. , Kokorina O. , Romanova A. , Rydyi S.
Published: December 2020

In the present article, we discuss an electrostatic field around four-bar trap, where in-phase AC voltage is applied to all electrodes. We consider shielding effect on trap’s field distribution. The ideal octupole field is obtained using a cylindrical grounded surface. Single-phase trap gives an opportunity to form an n-order multipole field within n + 1 number of electrodes. This approach reduces the number of electrodes in comparison with the classical case.
Oriented nanonetworks and submicron fibres of nickel as a conducting coating
Authors: Nizameev I R , Morozov M V , Nizameeva G R , Spiridonov S V , Kadirov M K
Published: December 2020

Within the framework of the work, a methodology was developed for applying oriented nickel nanonetworks to glass, combined into a single system with an oriented network of submicron nickel fibres. The applying technique is original and has not been previously reported in the literature. The basis of the technique is precipitation from the liquid phase by chemical reduction of the nickel salt. The created coating could be interesting for the application in the transparent electrodes field.
Influence of Fe2+ doping concentration on the structure and spectroscopic properties of transparent glass-ceramics based on Fe2+:ZnAl2O4 nanocrystals
Authors: Eremeev K , Dymshits O , Khubetsov A , Alekseeva I , Zapalova S , Tsenter M , Zhilin A. , Basyrova L , Loiko P , Popkov V
Published: December 2020

Zinc aluminosilicate glasses nucleated by titanium dioxide, both undoped and doped with 0.6 and 1.0 wt% FeO were prepared by conventional melt-quenching technique and subsequently converted to glass-ceramics by controlled nucleation and crystallization in the temperature range of 720 – 1200 °C. The glasses and glass-ceramics were characterized by X-ray diffraction, Raman and optical spectroscopy. The addition of FeO speeds up the liquid phase separation of the initial glasses and gahnite (ZnAl2O4), rutile (TiO2) and cristobalite (SiO2) crystallization. Ferrous ions enter the gahnite crystals leading to a variation of the absorption spectra of glass-ceramics as compared to those of glasses. The glass-ceramics exhibit a broadband (1.5-2.5 μm) absorption due to the 5E → 5T2 (5D) transition of Fe2+ ions in tetrahedral sites in gahnite nanocrystals. They are promising as materials for gain media and saturable absorbers of mid-infrared lasers.