bluuebunny/crossref_metadata_2025_split huggingface dataset:
An equation decoupling technique for identification of unstable aircraft with unsteady aerodynamic modelling
Authors: Singh J. , Raisinghani S. C. 
Published: March 2023

AbstractA simplified trailing vortex concept has been used to model unsteady aerodynamic effects onto the mathematical model for an augmented unstable aircraft. An output error method with, and without, an equation decoupling technique in the frequency domain has been used for the estimation of parameters. The two approaches of estimation are compared for the cases where unsteady effects are included or excluded from the estimation model. It is shown that the incorporation of the equation decoupling technique makes the estimation algorithm robust with respect to initial guess values of the parameters. Finally, the inclusion of unsteady aerodynamics is shown to reduce the variation in the parameter estimates due to different control input forms.
A generic harmonic rotor model for helicopter flight simulation
Authors: Chaimovich M. , Rosen A. , Rand O. 
Published: March 2023

AbstractA new rotor model for helicopter flight mechanics simulation is presented. The rotor dynamics are described using multiblade coordinates, and the aerodynamic loads include nonlinear effects such as stall and compressibility. These loads are described as harmonic series. The number of harmonics in the series determines the model accuracy. Thus by changing the number of harmonics from one to a large number, it is possible to obtain models that range between a quasi tip path plane approach and an accurate blade element model. The user of the model can very easily change the model accuracy and consequently its efficiency. The new rotor model is investigated and its application for trim and manoeuvre calculations is presented and discussed.
Scouting and Growing Diverse Undergraduate Talent: UCLA’s Race, Ethnicity, Politics & Society Lab
Authors: Pérez Efrén 
Published: March 2023

ABSTRACTThis article discusses the origins, metrics, and methods of UCLA’s Race, Ethnicity, Politics & Society Lab, which trains cadres of undergraduate researchers, many of whom are students of color. The article focuses intently on the connections between the professionalization of undergraduate researchers and the production of greater intellectual, racial, and gender diversity in a university setting. The article also provides a blueprint to steer undergraduate students toward producing peer-reviewed publications for major political science journals. Finally, specific strategies to initiate and sustain a research lab operation with undergraduate researchers in mind are offered.
Mapping Byzantine Sericulture in the Global Transfer of Technology
Authors: Wu Gang 
Published: March 2023

AbstractThe transfer of sericulture into Byzantium is a critical episode in the global dissemination of silk production technology. However, it is now widely accepted that the explanatory model portraying the transfer as a one-off event is at odds with the historical facts. This article seeks to reassess the transfer of this technology through the lens of appropriation, interpreted as a process. Based on a detailed analysis of the limited evidence available, it attempts to reconstruct the process from transregional and diachronic perspectives, embracing, on the one hand, the transmission of sericulture from China to Byzantium and, on the other, its development in Byzantium over time. This reconstruction offers an explanation for unresolved historical problems. It also constitutes a template for modelling the global transfer of technology in the premodern world, potentially of great value for an in-depth understanding of the transfer.
Authoritarian Gender Equality Policy Making: The Politics of Domestic Violence in Russia
Authors: Johnson Janet Elise 
Published: March 2023

AbstractThis article provides an analytical framework for understanding why and how many authoritarian regimes have recently adopted reforms that address gender equality. I illustrate and hone the framework by tracing three policy-making processes on domestic violence in Russia, an important and least-likely case for such reforms. While recent scholarship finds the importance of international leverage, strategic actions by women’s groups, and regime interest in sidelining religious extremists, this study highlights other opportunities and agents and specifies authoritarian mechanisms such as intra-elite conflict, signaling between the autocrat and elites, and selective responsiveness. Drawing on the scholarship on authoritarian regime dynamics, policy making in Russia, and gender policy making, this study contributes to the literature on the relationship between gender and regime type by focusing on the micrologics of authoritarian policy making.
The emotional fabric of populism during a public health crisis: How anger shapes the relationship between pandemic threat and populist attitudes
Authors: Filsinger Maximilian , Hofstetter Nathalie , Freitag Markus 
Published: March 2023

AbstractWhile conventional wisdom connects crises and external threats to increasing support for populism, several questions remain unanswered. Following insights of affective intelligence theory (AIT), we posit that anger and fear elicited by pandemic threat relate differently to populist attitudes. While such relations have already been explored in the context of other hazards (such as financial turmoil, terrorism, or immigration), our study allows us to evaluate the emotional bedrocks of populism in the context of a threat that is not apparently connected to the classical political grievances underlying populism. Expanding the literature on psychological underpinnings of populism and on the political consequences of the pandemic, our analyses of original survey data support our contentions that pandemic threat-induced anger is positively related to populist attitudes while fear is negatively linked to populist stances. This holds in particular for anti-elitism and the Manichean outlook inherent in populism. Altogether, we provide new comparative evidence to the puzzle about the emotional bedrocks of populism by illuminating a domain that has not been systematically explored before.
Civilian victimization and ethnic attitudes in Africa
Authors: Villamil Francisco 
Published: March 2023

AbstractPrevious research shows that violence is an important factor driving ethnic identification and grievances, but most works that explore micro-level effects focus on specific cases and have limited external validity. This article looks at the individual-level consequences of civilian victimization in a large sample across Africa. Combining georeferenced survey data from several rounds of the Afrobarometer, victimization events from the UCDP-GED, and data on collective targeting from the ethnic one-sided violence dataset, it studies the effect of exposure to violence on ethnic identification and self-reported ethnic grievances. Results show that violence increases ethnic identification and ethnic grievances particularly when it is committed by state forces and among individuals who belong to an ethnic group that was collectively targeted in the past.
A novel passive shoulder exoskeleton for assisting overhead work
Authors: Ding Shuo , Reyes Francisco Anaya , Li Tong , Yu Haoyong 
Published: March 2023

Abstract
Shoulder exoskeletons (SEs) can assist the shoulder joint of workers during overhead work and are usually passive for good portability. However, current passive SEs face the challenge that their torque generators are often attached to the human arm, which adds a significant amount of weight to the user’s arms, resulting in additional energy consumption of the user. In this paper, we present a novel passive SE whose torque generator is attached to the user’s back and assists the shoulder joint through Bowden cables. Our approach greatly reduces the weight on the user’s arms and can accommodate complex shoulder joint movements with simple and lightweight mechanical structure based on Bowden cables. In addition, to match the nonlinear torque requirements of the shoulder joint, a unique spring-cam mechanism is proposed as the torque generator. To verify the effectiveness of the device, we conducted a usability test based on muscle activations of 10 healthy subjects. When assisting overhead work, the SE significantly reduced the mean and maximum electromyography signals of the shoulder-related muscles by up to 25%. The proposed SE contributes to further research on passive SE design to improve usability, especially in terms of reducing weight on human arms.
Effects of Issue- and Character-Based Narrative Political Ads on Ad Evaluations
Authors: Shen Fuyuan , Yang Guolan , Conlin Jeff , Diddi Pratiti 
Published: March 2023

Abstract: The purpose of the present study is to explore how narrative political ads interact with other message strategies in affecting recipients’ ad responses. To accomplish that, we conducted a 2 × 2 × 2 between-subjects experiment whereby participants viewed political ads manipulated by message format (non-narrative vs. narrative), message valence (negative vs. positive), and message focus (issue vs. character). Results suggested that narrative political ads elicited favorable advertising evaluations via increased transportation and reduced counterarguing. Moreover, when political ads attacked the competing candidate’s character, the narrative message led to higher levels of empathy and lower levels of counterarguing than the non-narrative message. Reduced counterarguing was the mechanism through which favorable ad evaluations were generated. These findings have both theoretical and practical implications.
Large Contribution of Ozone‐Depleting Substances to Global and Arctic Warming in the Late 20th Century
Authors: Sigmond M. , Polvani L. M. , Fyfe J. C. , Smith C. J. , Cole J. N. S. , England M. R. 
Published: March 2023

AbstractWhile previous studies have suggested a substantial role of ozone‐depleting substances (ODSs) in historical climate change, their relative contribution to historical anthropogenic warming has not been quantified before. Analyzing all‐but‐one‐forcing, 20‐member ensembles of historical simulations with a state‐of‐the‐art Earth System Model, we find that over the 1955–2005 period ODSs are responsible for 30% of global warming, 37% of Arctic warming, and 33% of summertime Arctic sea ice loss. Effective Radiative Forcing (ERF) calculations reveal that the global warming response to ODSs per unit of ERF is about 20% larger than for CO2, which may be due to stronger feedbacks and the difference in temporal evolution with ODSs having leveled off and CO2 still increasing in 2005. While the response to both peaks in the Arctic, the ODS ERF opposes Arctic amplification more than the CO2 ERF. Our findings highlight the importance of the Montreal Protocol for mitigating future climate change.
Deciphering the Signatures of Oceanic Convective Rain Cells Using Simultaneous Observations From C‐Band Synthetic Aperture Radar Onboard EOS‐04 Satellite and GPM Measurements
Authors: Subrahmanyam Kandula V. , Bothale Rajashree V. , Swapna Mullukutla , Chauhan Prakash 
Published: March 2023

AbstractEarth Observation Satellite (EOS)‐04 launched on 14 February 2022, carries a C‐band Synthetic Aperture Radar (SAR) for Agriculture, Forestry, Hydrology, and Flood mapping applications. In this paper, we have used C‐band SAR images and near‐simultaneous observations from the global precipitation measurements (GPM) to study the signatures of multiple convective rain cells. The bright patches are found on C‐band SAR imagery, which depicts the information of hydrometeors such as graupels or hails in the melting layer. For the first time, unambiguously estimated the diameter of the convective core rain cells from the C‐band SAR backscattered signal and compared with near‐simultaneous observations from GPM‐GMI and Ku‐band radar to confirm our findings. Thus, the present study demonstrates the potential of C‐band SAR for identifying the signatures of convective rain cells.
Universal Time Variations in the Magnetosphere and the Effect of CME Arrival Time: Analysis of the February 2022 Event that Led to the Loss of Starlink Satellites
Authors: Lockwood M. , Owens M. J. , Barnard L. A. 
Published: March 2023

AbstractWe study Universal Time (UT) variations in the magnetospheric response to Coronal Mass Ejection (CME) impacts, using the example of the two CMEs that led to the destruction of 38 out of 49 Starlink satellites in early February 2022. We employ the Expanding‐Contracting Polar Cap model to analyze the variation in the size of the ionospheric polar caps and an eccentric dipole model of the geomagnetic field and thereby quantify the UT variations caused by the inductive effect of the diurnal motions of the geomagnetic poles in a “geocentric‐solar” frame of reference (i.e., a frame with an X axis that points from the center of the Earth to the center of the Sun). The results show that use of a quasi‐steady convection model predicts a similar global power deposition into the thermosphere as that inferred here, but does not give the same division of that power between the northern and southern hemispheres. We demonstrate that, through the combined effects of the Russell‐McPherron dipole‐tilt mechanism on solar‐wind magnetosphere coupling and of the diurnal polar cap motions in a geocentric‐solar frame, the power deposited varies significantly with the arrival UT of the CMEs at Earth. We also show that in the events of early February 2022, both CMEs arrived at almost the optimum UT to cause maximum thermospheric heating.
Using Dark Fiber and Distributed Acoustic Sensing to Characterize a Geothermal System in the Imperial Valley, Southern California
Authors: Cheng Feng , Ajo‐Franklin Jonathan B. , Nayak Avinash , Tribaldos Veronica Rodriguez , Mellors Robert , Dobson Patrick ,   the Imperial Valley Dark Fiber Team
Published: March 2023

AbstractThe Imperial Valley, CA, is a tectonically active transtensional basin located south of the Salton Sea; the area hosts numerous geothermal fields, including significant hidden hydrothermal resources without surface manifestations. Development of inexpensive, rugged, and highly sensitive exploration techniques for undiscovered geothermal systems is critical for accelerating geothermal power deployment as well as unlocking a low‐carbon energy future. We present a case study utilizing distributed acoustic sensing (DAS) and ambient noise interferometry for geothermal reservoir imaging, utilizing unlit fiber‐optic telecommunication infrastructure (dark fiber). The study exploits two days of passive DAS data acquired in early November 2020 over a ∼28‐km section of fiber from Calipatria, CA to Imperial, CA. We apply ambient noise interferometry to retrieve coherent signals from DAS records and develop a bin stacking technique to attenuate the effects from persistent localized noise sources and to enhance retrieval of coherent surface waves. As a result, we are able to obtain high‐resolution two‐dimensional (2D) S wave velocity (Vs) structure to 3 km depth, based on joint inversion of both the fundamental and higher overtones. We observe a previously unmapped high Vs and low Vp/Vs ratio feature beneath the Brawley geothermal system, which we interpret to be a zone of hydrothermal mineralization and lower porosity. This interpretation is consistent with a host of other measurements including surface heat flow, gravity anomalies, and available borehole wireline data. These results demonstrate the potential utility of DAS deployed on dark fiber for geothermal system exploration and characterization in the appropriate geological settings.
Observational and Model Impact of Tonga Volcano Eruption on Schumann Resonance
Authors: Mezentsev A. , Nickolaenko A. P. , Shvets A. V. , Galuk Yu. P. , Schekotov A. Yu. , Hayakawa M. , Romero R. , Izutsu J. , Kudintseva I. G. 
Published: March 2023

AbstractTonga volcano eruption on 15 January 2022 was accompanied by an unprecedentedly high lightning activity in the volcano plume which significantly exceeded the lightning activity level of the whole globe. We compare model computations with the observed effect of the Tonga volcano eruption on the global electromagnetic Schumann resonance (SR). This SR disturbance was detected at many observatories covering the whole globe. SR power spectral density was computed using the updated model of the Earth‐ionosphere cavity, with the global lightning detections recorded by the World Wide Lightning Location Network, as a source. The modeled dynamics of the SR disturbances during Tonga eruption agrees qualitatively and quantitatively with SR recordings from six globally separated observatories. Unprecedentedly high lightning activity during the active phase of eruption caused significant suppression of the global lightning detection rate without noticeable effect on real global thunderstorm activity.
Estimating Net Carbon and Greenhouse Gas Balances of Potato and Pea Crops on a Conventional Farm in Western Canada
Authors: Quan Ningyu , Lee Sung‐Ching , Chopra Chitra , Nesic Zoran , Porto Paula , Pow Patrick , Jassal Rachhpal S. , Smukler Sean , Krzic Maja , Knox Sara H. , Black T. Andrew 
Published: March 2023

AbstractQuantifying the emissions of the three main biogenic greenhouse gases (GHGs), carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4), from agroecosystems is crucial. In this study continuous measurements of N2O, and CH4 emissions from potato and pea crops in southwest British Columbia, Canada were made using the eddy‐covariance (EC) technique. Flux footprint analysis, coupled with EC and manual nonsteady state chamber measurements, was used to address the spatial heterogeneity resulting from the field edge at the study site. Flux footprint corrections had a larger effect on N2O fluxes than CO2 fluxes because of a more pronounced difference in N2O fluxes between the crop and edge areas. After flux footprint corrections, the potato and pea crops were both weak CO2 sinks with annual net ecosystem exchange values of −57 ± 9 and −97 ± 16 g C m−2 yr−1, respectively. However, after taking carbon (C) export via crop harvest and C import via seeding into account, the potato crop shifted to being a moderate C source of 284 ± 55 g C m−2 yr−1, while the pea crop became near C neutral, sequestering only 30 ± 26 g C m−2 yr−1. Annual GHG balances, quantified by converting N2O and CH4 to CO2 equivalents as pulse emissions using respective global warming potentials on a 100‐year timescale, were 417 ± 88 and 152 ± 106 g CO2e m−2 yr−1 for the potato and pea crops, respectively, with N2O contributing the largest proportion to annual total GHG balances and outweighing the CO2 uptake from the atmosphere.
An Urban Scheme for the ECMWF Integrated Forecasting System: Global Forecasts and Residential CO2 Emissions
Authors: McNorton J. , Agustí‐Panareda A. , Arduini G. , Balsamo G. , Bousserez N. , Boussetta S. , Chericoni M. , Choulga M. , Engelen R. , Guevara M. 
Published: March 2023

AbstractThe impact of urbanization on local weather patterns affects over half the global population. Global numerical weather prediction systems have reached a resolution at which urban conurbations can be spatially resolved, justifying their representation within land surface parameterizations with the aim of improving local predictions. Additionally, real‐time atmospheric monitoring of trace gas emissions can utilize weather variables relevant for urban areas. We investigated whether a simple single‐layer urban canopy scheme can be used within a global forecast model to jointly improve predictions of near‐surface weather variables and residential CO2 emissions. The scheme has been implemented in the Integrated Forecast System used operationally at the European Centre for Medium‐Range Weather Forecasts running at ∼9 km horizontal resolution. First, we selected a suitable urban land cover map (ECOCLIMAP‐SG) based on comparisons with regional data and land surface temperature MODIS retrievals. The urban scheme is verified by providing improved 2 m temperature (∼10%) and 10 m wind (∼17%) RMSE values for both summer and winter months around urban environments. The influence of the scheme was most noticeable at night. Additionally, we have implemented a simple temperature‐dependent residential emissions model to calculate real‐time CO2 heating emissions. These were validated against existing offline products, national reporting and by comparing atmospheric simulations with total column CO2 observations. The results show an improved temporal variability of emissions, which arise from synoptic scale temperature changes. Given the improved predictability from the urban scheme for both weather and emissions, it will be operationally implemented in an upcoming model cycle.
Deep Electron Density Depletion Near Sunset Terminator on St. Patrick's Day Storm and Its Impacts on Skywave Propagation
Authors: Ankita M. , Tulasi Ram S. , Ajith K. K. , Sripathi S. 
Published: March 2023

AbstractThe plasma density distribution in the equatorial and low latitude ionosphere can often be severely disturbed during active space weather events that can have paramount impacts on the long‐distance high frequency (HF) radio wave (Skywave) communications through the ionosphere. On the St. Patrick's Day storm of 17 March 2015, a deep depletion of plasma with more than two orders of magnitude was observed over a narrow longitudinal sector near the sunset terminator. The controlled SAMI2 (Sami2 is Another Model of the Ionosphere) simulations indicate that a large equatorial vertical drift around sunset terminator can produce such a deep electron density depletion and strong reinforcement of equatorial ionization anomaly. The impacts of these ionospheric density disturbances on the Skywave communication systems have been investigated using an HF propagation simulator that solves the propagation path of radio waves under given background ionospheric conditions. The results clearly demonstrate that the usable HF spectrum for Skywave communications is reduced by more than 50% over the region of depletion. Further, large areas of skip zones, where the Skywave signals are not receivable, are produced due to low ionospheric densities over this region. This study can have important applications in the planning and operation of Skywave systems during the active space weather periods.
Sub-50 nm optical imaging in ambient air with 10× objective lens enabled by hyper-hemi-microsphere
Authors: Wu Guangxing , Zhou Yan , Hong Minghui 
Published: March 2023

AbstractOptical microsphere nanoscope has great potential in the inspection of integrated circuit chips for semiconductor industry and morphological characterization in biology due to its superior resolving power and label-free characteristics. However, its resolution in ambient air is restricted by the magnification and numerical aperture (NA) of microsphere. High magnification objective lens is required to be coupled with microsphere for nano-imaging beyond the diffraction limit. To overcome these challenges, in this work, high refractive index hyper-hemi-microspheres with tunable magnification up to 10× are proposed and realized by accurately tailoring their thickness with focused ion beam (FIB) milling. The effective refractive index is put forward to guide the design of hyper-hemi-microspheres. Experiments demonstrate that the imaging resolution and contrast of a hyper-hemi-microsphere with a higher magnification and larger NA excel those of a microsphere in air. Besides, the hyper-hemi-microsphere could resolve ~50 nm feature with higher image fidelity and contrast compared with liquid immersed high refractive index microspheres. With a hyper-hemi-microsphere composed microscale compound lens configuration, sub-50 nm optical imaging in ambient air is realized by only coupling with a 10× objective lens (NA = 0.3), which enhances a conventional microscope imaging power about an order of magnitude.