bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum steerability of two qubits mediated by one-dimensional plasmonic waveguides
Authors: Zhang Ye-Qi , Ding Xiao-Ting , Sun Jiao , Wang Tian-Hu
Published: August 2022

We study the dynamics of the quantum steering between two separated qubits trapped in a one-dimensional plasmonic waveguide. By numerical methods, we calculate the quantum steerability and other quantum correlations, i.e., entanglement, discord, and coherence, for both cases with and without laser driving fields. It is found that steerability may exhibit a sudden disappearance and sudden reappearance phenomenon. Specifically, there exist time windows with no steerability but finite entanglement. The effects of plasmon wavenumber and the distance between the two qubits on steerability are also examined. Furthermore, we show that quantum steerability is tunable by adjusting the laser driving fields.
Magnonic band-pass and band-stop filters with structurally modulated waveguides
Authors: Feng Lai-He , Ma Mang-Yuan , Liu Zhi-Hua , Xie Kai-Le , Ma Fu-Sheng
Published: August 2022

Magnonics is a fascinating and emerging field, which mainly studies processing information with spin waves. Magnonic devices with in-plane magnetization have recently been realized. Because of the isotropic propagation, magnonic devices based on perpendicular magnetization are attracting extensive interest. Here, we numerically demonstrate two magnonic filters with out-of-plane magnetization using micromagnetic simulations. The band-pass and the band-stop functions have been realized in two structurally modulated waveguides, respectively. The intensity of spin waves is manipulated when they arrive at the uniformly/non-uniformly magnetized modulators, which results in the variation of transmission coefficients. It is found that the proposed filters can work at multiple frequencies, which can be further adjusted by the external magnetic field. Our designed magnonic devices with Néel-type skyrmion could promote the development of spin wave computing using spin textures.
Analysis of Ground Level Enhancement Events of 1989 September 29; 2001 April 15 and 2005 January 20
Authors: Ugwoke R. E. , Ubachukwu A. A. , Urama J. O. , Okike O. , Alhassan J. A. , Chukwude A. E.
Published: August 2022

We present the results of analyses of the ground level enhancements (GLEs) of cosmic ray (CR) events on 1989 September 29; 2001 April 15 and 2005 January 20. This involves examination of hourly raw CR counts of an array of neutron monitors (NMs) spread across different geographical latitudes and longitudes. Using awk script and computer codes implemented in R software, the pressure corrected raw data plots of the NMs were grouped into low-, mid- and high-latitudes. The results show both similarities and differences in the structural patterns of the GLE signals. In an attempt to explain why the CR count during the decay phase of GLEs is always higher than the count before peak, we interpreted all counts prior to the peak as coming from direct solar neutrons and those in the decay phase including the peak as coming from secondary CR neutrons generated by the interactions of primary CRs with the atoms and molecules in the atmosphere. We identified NMs that detected these primary neutrons and found that they are close in longitude. Previous authors seemingly identified these two species as impulsive and gradual events. Although there are a number of unexplained manifestations of GLE signals, some of the results suggest that geomagnetic rigidity effectively determines the intensity of CRs at low- and mid-latitudes. Its impact is apparently insignificant in high-latitude regions. Nevertheless, the results presented should be validated before making any firm statements. Principally, the contributions of the ever-present and intractable CR diurnal anisotropies to GLE signals should be accounted for in future work.
Photometric Analysis of Three Potential Red Nova Progenitors
Authors: Wadhwa Surjit S. , De Horta Ain , Filipović Miroslav D. , Tothill N. F. H. , Arbutina Bojan , Petrović Jelena , Djurašević Gojko
Published: August 2022

We present photometric analysis of three bright red nova progenitor contact binary systems: ASAS J082151-0612.6, TYC 7281-269-1 and TYC 7275-1968-1. The primary components in all three systems are solar-type low mass stars with radii somewhat larger than their zero age main sequence counterparts. The secondaries, as in most contact binary systems, have radii and luminosities well above their main sequence counterparts. All three have extremely low mass ratios ranging from 0.075 to 0.097 and two have high degrees of contact, in excess of 75%. All three have mass ratios and separations below the theoretical values for orbital stability. Chromospheric activity, a hallmark of magnetic activity and magnetic braking, considered important in mediating angular momentum loss, is also explored. All three systems demonstrate the O’Connell effect, and all systems require the introduction of star spots for a better light curve solution. In addition, we show that ASAS J082151-0612.6 and TYC 7281-269-1 have a UV color excess in the range indicating high chromospheric activity. Another measure of potential significant magnetic activity is X-ray luminosity; TYC 7275-1968-1 and probably also TYC 7281-269-1 have X-ray luminosity well above other contact binary systems. We conclude that it is likely that all three are unstable and hence are potential merger candidates.
Gyrokinetic modelling of the Alfvén mode activity in ASDEX Upgrade with an isotropic slowing-down fast-particle distribution
Authors: Vannini F. , Biancalani A. , Bottino A. , Hayward-Schneider T. , Lauber P. , Mishchenko A. , Poli E. , Rettino B. , Vlad G. , Wang X.
Published: August 2022

In the present paper, the evolution of the Alfvén modes (AMs) is studied in a realistic ASDEX Upgrade equilibrium by analyzing the results of simulations with the global, electromagnetic, gyrokinetic particle-in-cell code ORB5. The energetic particles (EPs) are modelled both via the newly implemented isotropic slowing-down and with Maxwellian distribution functions. The comparison of the numerical results shows that modelling the EPs with the equivalent Maxwellian rather than with the slowing-down, does not significantly affect the frequency of the driven AM, while its growth rate appears to be underestimated with a quantitative difference as large as almost 30%. Additionally the choice of the isotropic slowing-down allows a better description of the nonlinear modification of the dominant AM frequency, while an equivalent Maxwellian underestimates it. A good comparison with the experimental spectrogram is found.
Computer Modelling of Intrinsic Defects and Th Incorporation in MgF2: What we can Learn from Atomistic Modelling and DFT Approaches
Authors: Jackson R A , Valerio M E G
Published: August 2022

The doping of MgF2 with the 229 isotope of Th is of interest in the development of nuclear clock devices. This paper describes atomistic modelling of MgF2, its intrinsic defects and Th doping, and compares the results with a recent study using Density Functional Theory (DFT).
Multi-scale simulations and phase stability prediction of mixed Li2S1-xSex system
Authors: Masedi M C , Ngoepe P E
Published: August 2022

Lithium-sulfur (Li-S) batteries are a popular Li-ion alternative because they have a high capacity (1672 mAhg1) and energy density (2500 Wh kg1) while being inexpensive, environmentally friendly, and lightweight [1–3]. During cycling, Li/S is hampered by the low conductivity of S and the solubility of intermediary polysulfide species. Se and mixed SexSy have been shown to offer an appealing new class of cathode materials with good electrochemical performance in both Li and Na ion processes [4]. These new Se and Li/SexSy electrodes can cycle at ambient temperature, unlike existing Li/S batteries, which can only operate at high temperatures. Room temperature cycling is possible using Li/SexSy electrodes. Empirical interatomic potentials of Li2S were generated and confirmed against existing experimental and predicted structure, elastic properties, and phonon spectra in order to analyse large systems and the impact of temperature effectively. Complex high-temperature changes including Li2S melting were also replicated, as predicted by molecular dynamics simulations.
Computer Modelling of Defects in Ba2YNbO6
Authors: Figueiredo Derinaldo S. , Mattos Emanuel Felipe dos S. , Araujo Romel M.
Published: August 2022

The structural properties of Ba2YNbO6 were adjusted and compared with experimental data through an interatomic potential that was optimized here and is based on a model known as the shell model used in this work for oxygen ions. Intrinsic and extrinsic defects were calculated based on the minimization of the crystal lattice energy through computational modeling. Calculations showed that rare earth ions prefer to incorporate the Y3+ site and Mn4+ the Nb5+ site, thus being more energetically favorable.
Study of the dielectric relaxation mechanisms in KNbO3-based electro-ceramics
Authors: Silva M C O , Silva A C , Oliveira M A , Mendez-González Y , M’Peko J-C , Hernandes A C , Guerra J D S
Published: August 2022

Electro-ceramics based on the KNbO3 ferroelectric system were synthesized from the solid-state reaction sintering method. In particular, the electrical properties have been investigated at room temperature in the (1−x)KNbO3−xBaNi1/2Nb1/2O3−δ (KBNN) solid-solution. The dielectric relaxation mechanisms have been analyzed as a function of the oxygen vacancy (δ) concentration and the frequency dispersion of the complex dielectric permittivity was analyzed in a wide frequency range. The obtained results were discussed within the framework of the current models reported in the literature for the dielectric relaxation processes.
Structural study of the La-modified AgNbO3 lead-free ceramic system
Authors: Jesus K F S , Silva A C , Mendez-González Y , Guerra J D S
Published: August 2022

The structural properties in Ag1−x
La
x
NbO3 ceramics (where x = 0.005) have been systematically investigated at room temperature by using X-ray diffraction (XRD) technique and Raman spectroscopy. The studied sample has been synthesized via the conventional solid-state reaction method. The XRD result confirmed the formation of a single-phase with orthorhombic crystal structure for the studied composition. The signature of the Raman spectrum revealed structural modification with the inclusion of the doping element, with respect to the pure AgNbO3 system, showing additional modes in the middle wavenumbers range (570–758 cm−1).
On the structural characteristics of 45S5-xSFO bioglass-ceramic composites for medical applications
Authors: Santos L L , Mendez-González Y , Silva A C , Oliveira R C , Dantas N O , Guerra J D S
Published: August 2022

Bioactive ferromagnetic glass-ceramics composites have been prepared through the combination of the quenching and solid-state reaction (SSR) sintering methods, viewing their integration in biomedical applications. The material under study consists of a glassy system with the chemical formula (94-2x)SiO2−xNa2O−xCaO-6P2O5, which acts as host-matrix for the magnetic phase (strontium ferrite). The samples were obtained by a modified incorporation technique, where the magnetic phase, previously synthetized by the SSR method, was added to the glass-matrix in desired proportions. The physical properties were investigated considering the analysis of the X-ray diffraction as well as Raman spectroscopy techniques, both performed at room temperature. Results revealed the formation of partially crystallized bioglass-ceramics, with a strong influence of the magnetic phase on the crystallization kinetics, which suggests the obtained bioactive composites promising materials for clinical treatments.
Synthesis and characterization of Bi1−xLaxFeO3multiferroic thin films
Authors: Mariano M A S , Mendez-González Y , Silva A C , Guerra J D S
Published: August 2022

Lanthanum modified BiFeO3thin films were prepared via the sol-gel method and deposited through the dip-coating technique on ITO coated substrates. The structural properties were investigated at room temperature from X-ray diffraction as well as Raman spectroscopy. Results confirm the formation of the perovskite structure without secondary phases, thus corroborating the high-quality of the obtained thin films. Well-defined and nanometric scale grains have been obtained from atomic force microscopy, revealing indeed crack-free surfaces. From the technological point of view, this result is very important since residual stresses promoted by surface cracks led to additional conduction behavior, which could affect the real electric response of the sample to be used in electronic devices.
Performance of photosensors in a high-rate environment for gas Cherenkov detectors
Authors: Peng C. , Xie J. , Joosten S. , Meziani Z.-E. , Jones M. , Kaczanowicz E. , Rehfuss M. , Sparveris N. , Paolone M. , Foley M. , Minot M. , Popecki M.
Published: August 2022

The solenoidal large intensity device (SoLID) at Jefferson Lab will push the boundaries of luminosity for a large-acceptance detector, which necessitates the use of a light-gas threshold Cherenkov counter for online event selection. Due to the high luminosity, the single-photon background rate in this counter can exceed 160 kHz/cm2 at the photosensors. Therefore, it is essential to validate the high-rate limits of the planned photosensors and readout electronics in order to mitigate the risk of failure. We report on the design and an early set of studies carried out using a small Cherenkov counter in a high-rate environment up to 60 kHz/cm2, in Hall C at Jefferson Lab. Commercially available multi-anode photomultipliers (MaPMT) and low-cost large-area picosecond photodetectors (LAPPD) were tested using the JLab FADC250 modules for readout. The test beam results show that the MaPMT array and the internal stripline LAPPD can detect and identify single-electron and pair-production events in high-rate environments. Due to its higher quantum efficiency, the MaPMT array provided a better separation between the single-electron and the pair-production events compared to the internal stripline LAPPD. A GEANT4 simulation confirms the beam test performance of our counter device.
Biomaterials with stiffness gradient for interface tissue engineering
Authors: Cai Jialun , Wang Junjuan , Sun Chenxuan , Dai Jianwu , Zhang Can
Published: August 2022

Interface tissue engineering is a rapidly growing field that aims to develop engineered tissue alternates with the goal of promoting integration between multiple tissue types. Engineering interface tissues is a challenging process, which requires biomaterials with specific composition, stiffness, cell types, and biochemical molecules. Among these, stiffness-controllable substrates have been developed to investigate the effect of stiffness on cell behavior. Especially these substrates with graded stiffness are advantageous since they allow multiple cell types differentiation and the following tissue development. In this review, we highlight various types of manufacturing techniques that can be applied to fabricate scaffolds with stiffness gradient, discuss methods to characterize them, and gradient biomaterials for regulating cellular behavior including attachment, migration, proliferation, and differentiation. We also address fundamentals of interface tissue organization, and stiffness gradient biomaterials for interface tissue regeneration. Potential challenges and future prospects of this emerging field are also included.
Comparison of microscale traffic emission models for urban networks
Authors: Quaassdorff Christina , Smit Robin , Borge Rafael , Hausberger Stefan
Published: August 2022

Traffic-related air quality issues remain in urban areas worldwide. For this reason, there is an increasing need to estimate the contribution of road traffic to atmospheric emissions at local level with high temporal and spatial resolution. Modal models compute emission rates as a function of specific engine or vehicle operating conditions at the highest resolution (seconds). They can be applied for microscale studies being a cost-effective tool to emulate differences in emissions levels in road networks. Two modal emission models, the Australian PΔP (Power-delta-Power) and the simplified version of the European PHEM (Passenger Car and Heavy-duty Emission Model), PHEM-light model, have been used. Also, a comparison to the cycle-variable emission model VERSIT+micro (Netherlands organisation for applied scientific research state of the art traffic emission model) has been performed. For the comparison of both modal models, the main variables involved in traffic emission calculation were identified. 1 Hz speed-time profiles for individual vehicles were generated with the traffic microsimulation model VISSIM (Vehrkehr in Statden SIMulation) for different traffic conditions. To understand the response of modal models, detailed estimations of NO
X
emissions and fuel consumption were compared for different vehicle classes. Instantaneous emission profiles for individual driving patterns are highly sensitive to speed-acceleration profiles, vehicle mass, and road gradient, which are essential variables for the emission calculation. Although there are differences between European and Australian models, engine power and load were used to map vehicle classes for a more consistent comparison. It is essential to accurately define these parameters for each vehicle class in addition to detailed driving patterns to obtain high-resolution emissions estimates. In this sense, a larger number of vehicle classes included in the model provides more flexibility to develop representative emissions estimates. Emission predictions between modal models were reasonably consistent presenting larger differences with the cycle-variable model, despite both modal models being based on different on-road fleet measurements. In conclusion, analysing emission estimations for different traffic conditions demonstrates the importance of an accurate definition of the model parameters for a specific vehicle fleet.
ABM-IAM: optimal climate policy under bounded rationality and multiple inequalities
Authors: Safarzyńska Karolina , van den Bergh Jeroen C J M
Published: August 2022

Despite considerable concern about potentially inequitable effects of climate policy, models fall short in assessing their implications for policy design. To address this issue, we develop an agent-based climate-economy model, ABM-IAM, as a disaggregated, behavioural approach to integrated climate assessment. It describes networks of heterogeneous consumers, banks, power plants and firms, and is calibrated on patterns of growth and carbon dioxide emissions generated by the DICE model of Nordhaus. Whereas the latter assumes full employment and abstains from a financial sector and inequality considerations, our approach relaxes these restrictions to obtain a more reliable assessment of climate policy impacts. We show that inequalities in labour and capital income serve as essential but overlooked links between climate-change damages and optimal climate policy. Our result show that lower inequalities of labour income increase the social cost of carbon (SCC), while the impact of capital income inequalities on the SCC depends on the share of population receiving capital rents.
Generalized hydrodynamics of the KdV soliton gas
Authors: Bonnemain Thibault , Doyon Benjamin , El Gennady
Published: August 2022

We establish the explicit correspondence between the theory of soliton gases in classical integrable dispersive hydrodynamics, and generalized hydrodynamics (GHD), the hydrodynamic theory for many-body quantum and classical integrable systems. This is done by constructing the GHD description of the soliton gas for the Korteweg–de Vries equation. We further predict the exact form of the free energy density and flux, and of the static correlation matrices of conserved charges and currents, for the soliton gas. For this purpose, we identify the solitons’ statistics with that of classical particles, and confirm the resulting GHD static correlation matrices by numerical simulations of the soliton gas. Finally, we express conjectured dynamical correlation functions for the soliton gas by simply borrowing the GHD results. In principle, other conjectures are also immediately available, such as diffusion and large-deviation functions for fluctuations of soliton transport.
(Dis)assortative partitions on random regular graphs
Authors: Behrens Freya , Arpino Gabriel , Kivva Yaroslav , Zdeborová Lenka
Published: August 2022

We study the problem of assortative and disassortative partitions on random d-regular graphs. Nodes in the graph are partitioned into two non-empty groups. In the assortative partition every node requires at least H of their neighbors to be in their own group. In the disassortative partition they require less than H neighbors to be in their own group. Using the cavity method based on analysis of the belief propagation algorithm we establish for which combinations of parameters (d, H) these partitions exist with high probability and for which they do not. For

H
>

⌈

d

2

⌉

we establish that the structure of solutions to the assortative partition problems corresponds to the so-called frozen-one-step replica symmetry breaking. This entails a conjecture of algorithmic hardness of finding these partitions efficiently. For

H
⩽

⌈

d

2

⌉

we argue that the assortative partition problem is algorithmically easy on average for all d. Further we provide arguments about asymptotic equivalence between the assortative partition problem and the disassortative one, going through a close relation to the problem of single-spin-flip-stable states in spin glasses. In the context of spin glasses, our results on algorithmic hardness imply a conjecture that gapped single spin flip stable states are hard to find which may be a universal reason behind the observation that physical dynamics in glassy systems display convergence to marginal stability.
Detection of bacterial contaminants via frequency manipulation of amino-groups functionalized Fe3O4 nanoparticles based resonant sensor
Authors: Kale Vivek , Chavan Chetan , Bhapkar Sunil , Girija K G , Kale S N
Published: August 2022

Bacterial infections have a large impact on public health. Through this study, we report on the development of complementary split-ring resonators (CSRR) supplemented by functionalized nanoparticles to detect bacteria in the aqueous medium. Iron oxide (Fe3O4) nanoparticles were functionalized with amino groups using (3-aminopropyl) triethoxysilane (APTES) to form (APTES@Fe3O4) nanoparticles, which have a specific affinity towards the bacterial species. This affinity was evaluated using the Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacterial species. The resonant sensor was tuned at 430 MHz and the CSRR sensor bed was further activated using APTES@Fe3O4 nanoparticles. Bacterial detection was studied over a range of concentrations from 2.66 × 109 cells to 2.66 × 108 cells. The sensor actively responded to small changes in bacterial concentration, showing an overall shift in resonance frequency of ∼44 MHz (∼40 MHz/cell count) for E. coli and ∼55 MHz (50.43 MHz/cell count) for S. aureus. Dextran sulphate and Chitosan were used as the references. The magnetic character of the conjugated system exhibited strong interaction of the bacterial species with APTES@Fe3O4, justifying the high selectivity towards these species. This demonstrates the feasibility of a sensitive, fast, portable device, against the traditionally used time-consuming bio-assays.
FSS bandwidth design using miniaturized elements for angular stability in transmission
Authors: Littman Nickolas , O’Keefe Steven G , Galehdar Amir , Espinosa Hugo G , Thiel David V
Published: August 2022

Frequency-selective surfaces (FSSs) are commonly employed at microwave frequencies in electromagnetic filtering applications. This paper reports the use of cascaded dual miniaturized elements for radio secure environments where miniaturized elements have been used creating a reduced unit cell (<0.1 wavelengths), and exceptional angular stability. Thin, flexible and optically transparent FSS samples were fabricated by laser engraving elements into a conductive aluminium layer, with a supporting Mylar substrate (relative permittivity 2.7), and thickness of 65 μm. The linearly polarized transmission response was investigated numerically by exploring the scattering parameters and the surface currents at resonance. Miniaturized elements in both single and cascaded FSS structures, have been explored to create both broadband and multiband responses across the L and S frequency bands. The theoretical and experimental results were in good agreement for the fabricated dual element dual layer translated band-stop FSS, displaying a resonant frequency reduction of 70% compared to a square loop with the same dimensions, along with significantly broad operation bandwidths of 118% and 104% for simulated and measured, respectively. These improvements were due to the selection of the individual elements in the array, their geometric arrangement, and the introduction of additional layers with lateral offsets.
Rayleigh-Sommerfeld scalar diffraction by rotating apertures
Authors: Bhattacharyya Rhitabrata , Bhattacharyya Saugata , Biswas Shyamal
Published: August 2022

We have analytically explored the Rayleigh-Sommerfeld scalar diffraction for various rotating apertures such as rotating single-slit, rotating double-slit, rotating linear diffraction grating, and rotating regular polygonal aperture. Here the apertures are considered to be uniformly rotating along the axes perpendicular to the plane of the apertures and the diffracted fields are analysed in the far-field zone. We have compared the time-averaged intensity distributions for the rotating apertures with the intensity distributions for static circular apertures of the same area. We also have obtained angular speed of rotation dependent Fraunhofer diffraction formulae for the rotating apertures, in particular, the rotating single-slit, the rotating double-slit, and the rotating linear diffraction grating.
Effectiveness of emissions standards on automotive evaporative emissions in Europe under normal and extreme temperature conditions
Authors: Tipton Matthew J , Lathem Terry L , Fu Joshua S , Tschantz Michael F
Published: August 2022

Non-methane volatile organic compounds (NMVOCs) are primary precursors for the formation of ozone and secondary organic aerosol which contribute to increased public health risks. Throughout Europe, passenger vehicles contribute significantly to NMVOC emissions due to automotive evaporative emissions controls that are less stringent than those in the United States, Canada, China, and Brazil. Evaporative NMVOC emissions increase significantly, and associated air quality impacts are exacerbated, during periods of high temperature such as heatwaves, which continue to increase in frequency, duration, and intensity. Adoption of strict evaporative emission standards and controls such as onboard refueling vapor recovery systems (ORVR) can significantly reduce evaporative emissions during such events; however, emissions inventories used to inform policy decisions are developed using average temperature profiles which fail to capture the impact of heatwave events on evaporative emissions. This study evaluates the effectiveness of the previous generation (Euro5), current (Euro6d), and proposed (Euro7) emission control standards on evaporative emissions at high temporal and spatial resolution in western and central Europe during July 2019, a month in which a significant heatwave swept through the region. Using temperatures obtained from the Weather Research and Forecasting (WRF) model with observation data and an improved method for estimating evaporative emissions, it is estimated that per-vehicle evaporative NMVOC emissions within the study domain and period are reduced by 25.0% under current Euro6d standards and controls relative to Euro5 standards, and that proposed Euro7 controls, including ORVR, would provide an additional 35.3% emissions reduction relative to Euro6d. During heatwave periods, Euro7 controls demonstrate improved attenuation of temperature-driven emissions increases relative to Euro6d controls, with associated emissions within the study period and domain increasing by 23.4% on average under Euro7 controls versus 29.4% under Euro6d controls. While this study does not quantify the effect of heatwaves and emissions controls on total annual emissions, the results for the study period of July 2019, combined with the low implementation cost of proposed Euro7 evaporative controls and projected continued dominance of petrol vehicles in the European fleet through the middle of this century, suggest that significant NMVOC emissions reductions and associated air quality and health impacts are achievable through the adoption of these more stringent standards and control systems.
Fabrication of Al-Ni-Al2O3 metal matrix composite coating on AA1100 wrought aluminium alloy by Gas Tungsten Arc (GTA) coating technique
Authors: Kumar Anand , Kumar Das Anil
Published: August 2022

The present paper describes about the Al-Ni-Al2O3 composite coating, which was developed on AA1100 aluminium alloy by gas tungsten arc (GTA) cladding method. The coating was developed by use of different composition of Al, Ni and Al2O3 mixed powders. Scanning electron microscopy (SEM) with energy dispersive x-ray (EDS) and x-ray diffractometry (XRD) were used to examine the microstructure and phase formation of the coating. Vickers microhardness and dry sliding wear test were used to study the mechanical and tribological properties of the coated layer under various normal loading conditions. It was observed that the increase in percentage composition of Al2O3 improved the metallurgical and mechanical properties of the coated layer. It was found that due to the development of Al2O3 reinforced intermetallic matrix composite the hardness and wear resistance of coated layer increased as compare to the AA11000 aluminium alloy substrate. It was also found that due to these phases the coefficient of friction of coated layer was lower than the substrate and the wear resistance of coated layer was higher than that of the substrate. The maximum hardness of coated layer was found to be nearly 26 times higher than that of the AA1100 aluminium alloy substrate. Also, the wear resistance of coated layer was nearly five to eight times higher than that of the AA1100 aluminium alloy substrate.
Contribution of Increases in Late Systolic Ejection Volume to the Impact of Heart Rate on Central Arterial Pulse Pressure in a Community Sample
Authors: Mthembu Nonhlanhla , Norton Gavin R , Peterson Vernice R , Naran Ravi , Yusuf Suraj M , Tade Grace , Bello Hamza , Bamaiyi Adamu , Libhaber Carlos D , Dessein Patrick , Peters Ferande , Sareli Pinhas , Woodiwiss Angela J
Published: August 2022

BACKGROUND

A lower heart rate (HR) increases left ventricular (LV) ejection volume. Whether this contributes to the adverse effects of HR on central pulse pressure (PPc) through reservoir volume effects is uncertain.

METHODS

Using noninvasive central pressure, aortic velocity, and diameter measurements in the outflow tract (echocardiography), we assessed the role of LV ejection volume as a determinant of HR relations with PPc in 824 community participants.

RESULTS

A lower HR was independently associated with both stroke volume (SV) (P < 0.001) and a shift in ejection volume from early (until the first systolic shoulder) to late (from first systolic shoulder to peak PP) systole (P < 0.05 to P < 0.005). Adjustments for LV end diastolic volume markedly diminished HR relations with SV and indexes of the shift in ejection volume to late systole. A lower HR was also independently associated with increases in forward traveling pressure waves (Pf) and PPc (P < 0.0001). However, adjustments for neither SV, nor indexes of a shift in ejection volume to late systole modified HR-Pf or PPc relations. This was despite relationships between indexes of a shift in ejection volume to late systole and both Pf and PPc (P < 0.0001). In contrast, adjustments for the increases in re-reflected and backward traveling wave pressures with a lower HR, eliminated HR-Pf and PPc relations.

CONCLUSIONS

In contrast to current thought, a lower HR is not associated with increases in PPc through an impact of increases in late systolic ejection volume on aortic reservoir volume, but rather through increases in backward wave pressures.
The Children of Other Lands and the Strategic Dissonance of Migrant Marginality
Authors: Miller Joshua L
Published: August 2022

This essay takes up a long-forgotten book series to argue for an overlooked historical role of early migrant narratives. These works pursued innovative formal experimentation in the era of literary realism rather than obsolete realist techniques in the time of modernisms. Migrant writers adapted techniques drawn from naturalism (by exchanging radical contingency for determinism) to depict lives buffeted by unpredictable global as well as national forces. These authors infused their works with productive distortion, turning the methods of anthropology and sociology into offbeat narratives that loop time, shuffle perspectives, mix genres and use photographs that interrogate their own evidentiary status. Not only did these writers anticipate later narrative modes of prominent modernists and postmodernists, but they also developed forms and aesthetics that long predate innovations by twentieth-century writers of migrancy, such as Carlos Bulosan and Maxine Hong Kingston. Despite twenty-first century expectations that earlier eras had simpler notions of transnational subjectivity, early US migrant narratives not only eschewed the unified paradigms formulated by contemporaries, but the emergent genre of migrant narrative preceded those paradigms. To combat the massification of immigrant experience, migrant intellectuals fashioned self-reflexive narrative forms to represent their native-informant narrator-protagonists simultaneously as both social scientific observers and the objects of analysis.

Despite twenty-first century expectations that earlier eras had simpler notions of transnational subjectivity, early US migrant narratives not only eschewed the unified paradigms formulated by contemporaries, but . . . preceded those paradigms and actively, if vainly, sought to counter [them].
Racial Capitalism and the Border
Authors: Hyoung Song Min
Published: August 2022

What is racial capitalism? This is a term that comes up frequently in the articles in this all-too-timely special essay on Exiles, Migrants, and Refugees. With the help of Cedric Robinson, Jodi Melamed, and Robin D. G. Kelley—and loosely modeled on Ruth Wilson Gilmore’s famous definition of racism—this commentary defines racial capitalism as a system for the production of surplus value through the maintenance and exaggeration of human group differences, made possible by the movement of large groups of people. The commentary then considers how this term guides the contributors of this special issue in thinking about a wide range of historical periods, geographical locations, and groups of people as they have experienced, again and again, a physical mobility that has been coerced or compulsory more often than voluntary. As much as racial capitalism might keep such groups apart from others, it also brings them into contact with one another and makes new social relations possible. It concludes with a call for greater attention to climate change and its significance for understanding the growing strength of anti-immigrant populism and the militarization of national borders all over the world.
scWMC: weighted matrix completion-based imputation of scRNA-seq data via prior subspace information
Authors: Su Yanchi , Wang Fuzhou , Zhang Shixiong , Liang Yanchun , Wong Ka-Chun , Li Xiangtao
Published: August 2022

Motivation

Single-cell RNA sequencing (scRNA-seq) can provide insight into gene expression patterns at the resolution of individual cells, which offers new opportunities to study the behavior of different cell types. However, it is often plagued by dropout events, a phenomenon where the expression value of a gene tends to be measured as zero in the expression matrix due to various technical defects.

Results

In this article, we argue that borrowing gene and cell information across column and row subspaces directly results in suboptimal solutions due to the noise contamination in imputing dropout values. Thus, to impute more precisely the dropout events in scRNA-seq data, we develop a regularization for leveraging that imperfect prior information to estimate the true underlying prior subspace and then embed it in a typical low-rank matrix completion-based framework, named scWMC. To evaluate the performance of the proposed method, we conduct comprehensive experiments on simulated and real scRNA-seq data. Extensive data analysis, including simulated analysis, cell clustering, differential expression analysis, functional genomic analysis, cell trajectory inference and scalability analysis, demonstrate that our method produces improved imputation results compared to competing methods that benefits subsequent downstream analysis.

Availability and implementation

The source code is available at https://github.com/XuYuanchi/scWMC and test data is available at https://doi.org/10.5281/zenodo.6832477.

Supplementary information

Supplementary data are available at Bioinformatics online.
What is a Digital Twin?
Authors: Morvan Michel
Published: August 2022

A digital twin isn’t just about exacting graphics, the technology enables fully working models of complete systems. We explore these virtual worlds and learn about the possibilities with Cosmo Tech’s CEO Michel Morvan.
Driving into the Cloud: What is Finops?
Authors: Bryant Jon
Published: August 2022

Organisations need to take a structured and proactive approach to predicting, tracking and managing the cost of their cloud services to meet their financial objectives, writes Jon Bryant MBCS CITP, Consultant with Strategic Blue.
The Art of Pure CSS
Authors: Melsom Blair
Published: August 2022

Diana Smith, Senior Frontend Web Developer and reluctant CSS master, speaks to Blair Melsom MBCS about creative coding at its finest.
The effect of orthodontic treatment on facial attractiveness: a systematic review and meta-analysis
Authors: Kouskoura Thaleia , Ochsner Tatjana , Verna Carlalberta , Pandis Nikolaos , Kanavakis Georgios
Published: August 2022

Background

Facial and smile attractiveness are significant motivating factor for patients to seek orthodontic treatment. Although there is a general belief that orthodontic treatment improves facial appearance, this has yet not been systematically evaluated.

Objective

The objective of this study was to assess the current evidence on the effect of orthodontic treatment on facial attractiveness.

Search Methods

Systematic and unrestricted search of nine databases were performed up to January 2022.

Selection Criteria

Studies evaluating facial attractiveness before and after orthodontic treatment.

Data Collection and Analysis

Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality, and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomized studies and with RoB-2 for randomized controlled trials (RCTs). Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were performed.

Results

Twenty studies were included in data synthesis; three randomized controlled clinical trials and 17 non-randomized clinical studies of retrospective or prospective design. One of the RCTs was found to have low risk of bias, one presented some concerns and the third showed a high risk of bias. All non-randomized studies showed either unclear or high risk of bias. Data syntheses showed that orthodontic treatment improved facial attractiveness ratings by 9% when compared with untreated controls (MD: 9.05/95% CI: 4.71; 13.39). A combination of orthodontics and orthognathic surgery also showed a positive effect of 5.5% (MD: 5.51/95% CI: 1.55; 9.47) when compared with orthodontic treatment alone. There was no difference in effect between extraction and non-extraction treatments (MD: −0.89/ 95% CI: −8.72; 6.94) or between different types of Class II correctors (MD: 2.21/95% CI: −16.51; 20.93).

Limitations

With the exception of two RCTs, included studies were of unclear or low quality.

Conclusions

Orthodontic treatment has a clinically weak effect on facial attractiveness when compared to no treatment. The same is true when a combined orthodontic/surgical treatment is compared to orthodontics alone.

Registration

PROSPERO #: CRD42020169904
Selfish evolution of placental hormones
Authors: Keegan Grace , Patten Manus M
Published: August 2022

We hypothesize that some placental hormones—specifically those that arise by tandem duplication of genes for maternal hormones—may behave as gestational drivers, selfish genetic elements that encourage the spontaneous abortion of offspring that fail to inherit them. Such drivers are quite simple to evolve, requiring just three things: a decrease in expression or activity of some essential maternal hormone during pregnancy; a compensatory increase in expression or activity of the homologous hormone by the placenta; and genetic linkage between the two effects. Gestational drive may therefore be a common selection pressure experienced by any of the various hormones of mammalian pregnancy that have arisen by tandem gene duplication. We examine the evolution of chorionic gonadotropin in the human lineage in light of this hypothesis. Finally, we postulate that some of the difficulties of human pregnancy may be a consequence of the action of selfish genes.
Clinical applications of heart rhythm monitoring tools in symptomatic patients and for screening in high-risk groups
Authors: Carrington Mafalda , Providência Rui , Chahal C Anwar A , Ricci Fabrizio , Epstein Andrew E , Gallina Sabina , Fedorowski Artur , Sutton Richard , Khanji Mohammed Y
Published: August 2022

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on symptom frequency. The choice of the most appropriate heart rhythm test should be guided by clinical evaluation and optimized following accurate characterization of underlying symptoms, ‘red flags’, risk factors, and consideration of cost-effectiveness of the different tests. This review provides evidence-based guidance for assessing suspected arrhythmia in patients who present with symptoms or in the context of screening, such as atrial fibrillation or advanced conduction disturbances following transcatheter aortic valve implantation in high-risk groups. This is intended to help clinicians choose the most appropriate diagnostic tool to facilitate the management of patients with suspected arrhythmias.
SLX5 deletion confers tolerance to oxidative stress in Saccharomyces cerevisiae
Authors: Thomas Pınar B , Kaluç Nur , Aybastıer Önder
Published: August 2022

Slx5, a subunit of a SUMO-targeted ubiquitin ligase (STUbL) in yeast, has been implicated in maintenance of genomic stability. SUMOylation is an important post-translational modification involved in the regulation of several important cellular processes and cellular response to various environmental stressors. Oxidative stress occurs when production of reactive oxygen species (ROS) exceeds the antioxidant defense capacity of the cell. Elevated ROS levels cause oxidative damage to important cellular macromolecules such as DNA, lipids, and proteins, which is associated with several diseases. Herein, we investigated the role of Slx5 in oxidative stress tolerance in Saccharomyces cerevisiae. We show that deletion of SLX5 increases survival of yeast cells in response to H2O2-induced oxidative stress in a cell cycle independent manner. Accumulation of intracellular ROS as well as DNA and lipid damages were reduced; expressions of antioxidant defense mechanism-related genes were increased in slx5Δ cells compared to wild type (WT) under oxidative stress. We also show that slx5Δ cells have increased intracellular ROS levels and oxidative damage to DNA and lipids compared to WT in the absence of oxidative stress. Thus, our data together suggest that an adaptive stress induced by SLX5 deletion increases tolerance to oxidative stress in slx5∆ cells.
Dementia and Sexuality: A Story of Continued Renegotiation
Authors: Claes Frauke , Enzlin Paul
Published: August 2022

This article presents a new conceptual framework that shows how dementia may affect the sexual relationship between partners, and how different actors become progressively more involved in “managing” the sexual relationship during consecutive phases of dementia, that is, the premorbid, preclinical, and clinical phases. Each phase challenges couples in different ways and these challenges may affect the expression of sexuality in their relationship. The person living with dementia and/or the partner’s desire to continue to be sexually active may result in conflicts with health care professionals and family members who want to protect the person living with dementia from becoming the perpetrator and/or the victim of “inappropriate” or “harming” sexual behavior. The framework posits that a diagnosis of dementia instigates a journey of renegotiating sexuality in which gradually more actors—who often approach sexuality from a sex-negative point of view—become involved. Therefore, the new framework starts from a sex-positive perspective and is presented together with a new research agenda that ensues from this framework. Research based on this framework that starts from the experience of both people living with dementia and their partners will help us to better understand the relational and sexual effects of a dementia diagnosis. This knowledge will enable health care professionals to provide tailored care with respect for the sexual needs of couples living with dementia. Hence, clinical implications arising from the framework are presented.
Refusing the Colonial Discourse of Animality: Insects, Farmworkers, and Ecological Solidarity in Helena María Viramontes’ Under the Feet of Jesus
Authors: Fink Lisa
Published: August 2022

This article explores the role of insects in Helena Maria Viramontes’ 1995 novel Under the Feet of Jesus. Drawing on decolonial theory and critical animal studies, it argues that the novel refuses the colonial discourse of animality, thereby offering a vision of ecological solidarity between farmworkers and insects. Close readings of insects demonstrate how the novel witnesses the mutual precarity of farmworkers and insects, as well as their collective resilience, in the landscape of US industrial agriculture. In this way, Viramontes’ novel presents an environmental imaginary that challenges the linked logics of human exceptionalism and white supremacy.