bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Nitrogen Oxide Emissions and San Joaquin Valley PM2.5 Impacts From Soils in California
Authors: Guo Lei , Chen Jianjun , Luo Dongmin , Liu Shang , Lee Hyung Joo , Motallebi Nehzat , Fong Angel , Deng Jia , Rasool Quazi Z. , Avise Jeremy C. , Kuwayama Toshihiro , Croes Bart E. , FitzGibbon Michael
Published: November 2020

Soils are a source of atmospheric nitrogen oxides (NOx), especially in regions with significant cropland where nitrogen (N) fertilizers are used to enhance crop yields. The magnitude of soil NOx emissions, however, varies substantially by region, depending on the local land use pattern and management activities. We estimated soil NOx emissions in California based on the DeNitrification‐DeComposition (DNDC) biogeochemical model, linked to a detailed spatial‐temporal differentiated California‐specific database. The DNDC‐generated surface fluxes were used in the Community Multiscale Air Quality (CMAQ) model to evaluate impacts of soil NOx emissions on formation of ambient particulate (PM2.5) nitrate in the San Joaquin Valley (SJV) where cropland is the dominant land use. The DNDC‐generated soil NOx emissions contribute approximately 1.1% of total anthropogenic NOx emissions in California, at an emission rate of roughly 24 t day−1 (as NO2) statewide and 9 t day−1 in the SJV. Cropland is the dominant source of soil NOx emissions in California, contributing nearly 60% of statewide soil NOx emissions, driven principally by fertilizer use. The PM2.5 nitrate concentrations simulated by CMAQ using the DNDC‐generated soil NOx emissions are compatible with those observed in the SJV, suggesting that soil NOx emissions have limited impacts on PM2.5 nitrate formation in the atmosphere. Our emission and air quality modeling results are further supported by long‐term ambient NOx‐to‐carbon monoxide (CO) and satellite NO2 data analyses in the SJV, which showed diurnal, monthly, and annual trends consistent with characteristics of NOx sources dominated by traffic combustion in both urban and agricultural regions.
Long‐Term Variability and Tendencies in Migrating Diurnal Tide From WACCM6 Simulations During 1850–2014
Authors: Ramesh K. , Smith Anne K. , Garcia Rolando R. , Marsh Daniel R. , Sridharan S. , Kishore Kumar K.
Published: November 2020

Long‐term variability and tendencies in migrating diurnal tide (DW1) are investigated for the first time using a three‐member ensemble of historical simulations by NCAR's Whole Atmosphere Community Climate Model, latest Version 6 (WACCM6) for 1850–2014 (165 years). The model reproduces the climatological features of the tide in temperature (T), zonal wind (U), and meridional wind (V). The amplitudes peak in the upper mesosphere and lower thermosphere (above ~0.001 hPa) at the equator forT(~10 K) and over 20–30°N and S latitudes forU(~15 m/s) andV(~25 m/s). The contributions of solar cycle (SC), quasi biennial oscillation (QBO) at 10 and 30 hPa, El Niño–Southern Oscillation (ENSO), ozone depleting substances (ODS), carbon dioxide (CO2), and stratospheric sulfate aerosols (volcanic eruptions) to change in annual mean amplitudes are analyzed using multiple linear regression. The tidal amplitudes in three components show a long‐term increase in the upper stratosphere (0.95–10.7 hPa) and the upper mesosphere (0.0001–0.01 hPa), predominantly due to increasing CO2with a smaller contribution from the trend in ENSO. Interestingly, the global mean tidal amplitude inTdecreases sharply after 1950–1960 until 1995 and then increases in association with changes in ODSs. The seasonal differences in tidal responses to the above indices can be as large as the overall signals. All the responses are stronger in the upper mesosphere; however, there is also a pronounced negative response of temperature tide to ODSs over middle to high latitudes around the stratopause (~1 hPa) during all seasons.
A Numerical Study of the Global Formation of Tropical Cyclones
Authors: Vu The‐Anh , Kieu Chanh , Chavas Daniel , Wang Quan
Published: November 2020

This study examines the large‐scale factors that govern global tropical cyclone (TC) formation and an upper bound on the annual number of TCs. Using idealized simulations for an aquaplanet tropical channel, it is shown that the tropical atmosphere has a maximum capacity in generating TCs, even under ideal environmental conditions. Regardless of how favorable the tropical environment is, the total number of TCs generated in the tropical channel possesses a consistent cap across experiments. Analyses of daily TC genesis events reveal further that global TC formation is intermittent throughout the year in a series of episodes at a roughly 2‐week frequency, with a cap of 8–10 genesis events per day. Examination of different large‐scale environmental factors shows that 600‐hPa moisture content, 850‐hPa absolute vorticity, and vertical wind shear are the most critical factors for this global episodic TC formation. Specifically, both the 850‐hPa absolute vorticity and the 600‐hPa moisture are relatively higher at the onset of TC formation episodes. Once TCs form and move to poleward, the total moisture content and the absolute vorticity in the main genesis region subside, thus reducing large‐scale instability and producing an unfavorable environment for TCs to form. It takes ∼2 weeks for the tropical atmosphere to remoisten and rebuild the large‐scale instability associated with the Intertropical Convergence Zone before a new TC formation episode can occur. These results offer new insight into the processes that control the upper bound on the global number of TCs in the range of 80–100 annually.
Late Pleistocene Carbon Cycle Revisited by Considering Solid Earth Processes
Authors: Köhler Peter , Munhoven Guy
Published: November 2020

The importance of volcanic CO2 release, continental weathering, and coral reef growth on the global carbon cycle has been highlighted by several different studies. Based on these independent approaches, we here revisit the last 800 kyr with the box model BICYCLE, which has been extended to be able to address these solid Earth contributions to the carbon cycle. We show that the volcanic outgassing of CO2 as a function of sea level change from mid‐ocean ridges and hot spot island volcanoes cannot be the generic process that leads during phases of falling obliquity to a sea level‐CO2 decoupling as has been suggested before. The combined contribution from continental and marine volcanism, if both lagging sea level change by 4 kyr, might have added up to 13 ppm to the glacial/interglacial CO2 rise. Coral reef growth as suggested by an independent model is during glacial terminations about an order of magnitude too high to be reconciled with meaningful carbon cycle dynamics. Global riverine input of bicarbonate caused by silicate and carbonate weathering is suggested to have been stable over Termination I. However, if weathering fluxes are changed by up to 50% in sensitivity experiments, the corresponding bicarbonate input might contribute less than 20 ppm to the deglacial atmospheric CO2 rise. The overall agreement of results with the new process‐based sediment module and the previously applied time‐delayed response function to mimic carbonate compensation gives confidence in the results obtained in previous applications of the BICYCLE model without solid Earth processes.
Forecasting SYM‐H Index: A Comparison Between Long Short‐Term Memory and Convolutional Neural Networks
Authors: Siciliano F. , Consolini G. , Tozzi R. , Gentili M. , Giannattasio F. , De Michelis P.
Published: November 2020

Forecasting geomagnetic indices represents a key point to develop warning systems for the mitigation of possible effects of severe geomagnetic storms on critical ground infrastructures. Here we focus on SYM‐H index, a proxy of the axially symmetric magnetic field disturbance at low and middle latitudes on the Earth's surface. To forecast SYM‐H, we built two artificial neural network (ANN) models and trained both of them on two different sets of input parameters including interplanetary magnetic field components and magnitude and differing for the presence or not of previous SYM‐H values. These ANN models differ in architecture being based on two conceptually different neural networks: the long short‐term memory (LSTM) and the convolutional neural network (CNN). Both networks are trained, validated, and tested on a total of 42 geomagnetic storms among the most intense that occurred between 1998 and 2018. Performance comparison of the two ANN models shows that (1) both are able to well forecast SYM‐H index 1 h in advance, with an accuracy of more than 95% in terms of the coefficient of determination R2; (2) the model based on LSTM is slightly more accurate than that based on CNN when including SYM‐H index at previous steps among the inputs; and (3) the model based on CNN has interesting potentialities being more accurate than that based on LSTM when not including SYM‐H index among the inputs. Predictions made including SYM‐H index among the inputs provide a root mean squared error on average 42% lower than that of predictions made without SYM‐H.
Beamline and Flight Comparisons of the ARMAS Flight Module With the Tissue Equivalent Proportional Counter for Improving Atmospheric Radiation Monitoring Accuracy
Authors: Gersey Brad “Buddy” , Tobiska W. Kent , Atwell William , Bouwer Dave , Didkovsky Leonid , Judge Kevin , Wieman Seth , Wilkins Richard
Published: November 2020

Ionizing radiation at aircraft and commercial suborbital spaceflight altitudes is driven by space weather and is a health concern for crew and passengers. We compare the response functions of two radiation detectors that were exposed to four different ground‐based laboratory radiation fields as well as flown alongside each other on aircraft. The detectors were a tissue equivalent proportional counter (TEPC) and a Teledyne silicon micro dosimeter chip that was integrated into an Automated Radiation Measurements for Aerospace Safety Flight Module (ARMAS FM). Both detectors were flown onboard commercial and research aircraft. In addition, both detectors were exposed neutrons at the Los Alamos Neutron Science Center, protons at Loma Linda University Medical Center, 56Fe particles at the NASA Space Radiation Laboratory, and also a gamma radiation source at Lawrence Livermore National Laboratory. The response of each of these instruments as well as derived dosimetric quantities are compared for each radiation exposure and the ratio for converting ARMAS absorbed dose in silicon to an estimated absorbed dose in tissue is obtained. This process resulted in the first definitive calibration of the silicon‐based detector like ARMAS to TEPC. In particular, with seven flights of both instruments together, the ARMAS‐derived dose in tissue was then validated with the TEPC‐measured dose in tissue and these results are reported. This work provides a method for significantly improving the accuracy of radiation measurements relevant to human tissue safety using a silicon detector that is easy to deploy and can report data in real time.
Current biomarker-associated procedures of cancer modeling-a reference in the context of IDH1 mutant glioma
Authors: Mehrjardi Narges Zare , Hänggi Daniel , Kahlert Ulf Dietrich
Published: November 2020

Isocitrate dehydrogenases (IDH1/2) are central molecular markers for glioblastoma. Providing in vitro or in vivo models with mutated IDH1/2 can help prepare facilities to understand the biology of these mutated genes as glioma markers, as well as help, improve therapeutic strategies. In this review, we first summarize the biology principles of IDH and its mutations and outline the core primary findings in the clinical context of neuro-oncology. Given the extensive research interest and exciting developments in current stem cell biology and genome editing, the central part of the manuscript is dedicated to introducing various routes of disease modeling strategies of IDH mutation (IDHMut) glioma and comparing the scientific-technological findings from the field using different engineering methods. Lastly, by giving our perspective on the benefits and limitations of patient-derived and donor-derived disease modeling respectively, we aim to propose leading research questions to be answered in the context of IDH1 and glioma.
Revelation of the dislocations in the C-face of 4H-SiC substrates using a microwave plasma etching treatment
Authors: Yu Jinying , Yang Xianglong , Peng Yan , Hu Xiaobo , Wang Xiwei , Chen Xiufang , Xu Xiangang
Published: November 2020

A novel microwave plasma etching technique was used to reveal various types of dislocation on the C-face of 4H-SiC.
Perspective on multi-scale simulation of thermal transport in solids and interfaces
Authors: Hu Ming , Yang Zhonghua
Published: November 2020

Phonon-mediated thermal transport is inherently multi-scale. The nature of multi-scale thermal transport is that there are different heat transfer physics across different length scales with strong entanglement and interaction with each other.
Novel hierarchical CuNiAl LDH nanotubes with excellent peroxidase-like activity for wide-range detection of glucose
Authors: Wu Lihong , Zhou Xuechun , Wan Gengping , Tang Yulin , Shi Shaohua , Xu Xuefei , Wang Guizhen
Published: November 2020

Novel hierarchical CuNiAl layered double hydroxide (CuNiAl LDH) nanotubes were prepared with the help of atomic layer deposition (ALD) method and exhibited excellent peroxidase mimicking property.
Cobalt ferrite nanozyme for efficient symbiotic nitrogen fixation via regulating reactive oxygen metabolism
Authors: Ma Jun , Song Zhiyong , Yang Jianhong , Wang Youning , Han Heyou
Published: November 2020

A cobalt ferrite nanozyme enables efficient symbiotic nitrogen fixation (260%) by regulating ROS metabolism and promoting accumulation of leghemoglobin.
Lactobacillus plantarum Y44 alleviates oxidative stress by regulating gut microbiota and colonic barrier function in Balb/C mice with subcutaneous d-galactose injection
Authors: Gao Yuan , Liu Yujun , Ma Fenglian , Sun Mengying , Song Yinglong , Xu Dongxue , Mu Guangqing , Tuo Yanfeng
Published: November 2020

The effect of L. plantarum Y44 administration on oxidative stress in Balb/C mice included the recovery of the gut microbiota and intestinal barrier function, influencing the glycerophospholipid metabolism, and activating Nrf-2/Keap-1 pathway.
A novel bromelain-MnO2 biosensor for colorimetric determination of dopamine
Authors: Liu Shimeng , Zhou Xiayu , Lv Changyin , Liu Ran , Li Shiya , Yang Guiying
Published: November 2020

We report a method for determining dopamine in serum via colorimetric sensing. This new method adopts bromelain-templated MnO2 nanosheets that possess high oxidase activity. 3,3′,5,5′-Tetramethylbenzidine (TMB) can be directly oxidized by bromelain-MnO2 nanosheets to oxTMB products.
A dissolving and glucose-responsive insulin-releasing microneedle patch for type 1 diabetes therapy
Authors: Zhang Yujie , Wu Mingxin , Tan Di , Liu Quan , Xia Re , Chen Min , Liu Yuangang , Xue Longjian , Lei Yifeng
Published: November 2020

A dissolving microneedle patch for responsive insulin release and type 1 diabetes therapy.
Optoelectronic synaptic transistors based on upconverting nanoparticles
Authors: Lian Haixia , Liao Qiufan , Yang Baidong , Zhai Yongbiao , Han Su-Ting , Zhou Ye
Published: November 2020

Transistors based on upconverting nanoparticles enable the simulation of artificial synaptic functions.
An open‐circuit fault diagnosis method for a submodule in a high‐frequency‐link modular multilevel DC transformer
Authors: Zhang Zhaoyun , Lin Pu
Published: November 2020

A high‐frequency‐link modular multilevel DC/DC transformer (H‐M2DCT) is used to interconnect DC bus bars of different voltage levels, and its safe and stable operation helps ensure the reliability of the entire DC grid. However, there is little research on the open‐circuit failures of H‐M2DCT submodules. Based on an electrical characteristics analysis of the open‐circuit fault of the H‐M2DCT submodule, this paper proposes a submodule open‐circuit fault detection method based on wavelet analysis. By performing wavelet analysis on each arm current, the coefficient is used as a criterion to detect whether a submodule open‐circuit fault has occurred on the arm; in terms of fault location, an over‐voltage protection method based on the submodule capacitor voltage is adopted. The proposed method requires neither the establishment of a complicated mathematical model nor the installation of additional sensors; thus, rapid detection and localisation of the fault submodule are achieved while reducing computational demand. In addition, the validity and effectiveness of the proposed method can be verified on the MATLAB/Simulink simulation platform.
Prevention of the current transformer saturation by using negative resistance
Authors: Sanati Saeed , Alinejad‐Beromi Yousef
Published: November 2020

In the power grid, various conditions may occur that saturate the core of a current transformer. Saturation of the protection core of the current transformers can cause a malfunction in the protection relays. To prevent malfunction of the protection relays caused by the current transformer saturation, software and hardware methods can be used. In the software method changes in the protection relay algorithm are used. In the hardware method special devices are used. A new hardware method is presented here, which uses compensation to prevent the occurrence of current transformer saturation. In the proposed method, compensation is done by controlling an applied voltage to the current transformer secondary terminals using negative resistance. The proposed method, despite its simplicity and cost‐effectiveness, has good performance in preventing saturation in various conditions. The high reliability in terms of the risk of secondary open circuit and its application in various saturation conditions, even in the case of severe saturation are the main advantages of the proposed method. Also, the proposed method does not produce distortion in the transformation of high‐order harmonics by the current transformer. To verify the effectiveness of the proposed method, prototype design and construction have been performed. The simulation and experimental results of laboratory tests have been presented and analysed.
Radio observations of HD 80606 near planetary periastron
Authors: de Gasperin F. , Lazio T. J. W. , Knapp M.
Published: November 2020

Context. All the giant planets in the Solar System generate radio emission via electron cyclotron maser instability, giving rise most notably to Jupiter’s decametric emissions. An interaction with the solar wind is at least partially responsible for all of these Solar System electron cyclotron masers. HD 80606b is a giant planet with a highly eccentric orbit, leading to predictions that its radio emission may be enhanced substantially near periastron.

Aims. This paper reports observations with the Low Frequency Array (LOFAR) of HD 80606b near its periastron in an effort to detect radio emissions generated by an electron cyclotron maser instability in the planet’s magnetosphere.

Methods. The reported observations are at frequencies between 30 and 78 MHz, and they are distinguished from most previous radio observations of extrasolar planets by two factors: (i) they are at frequencies near 50 MHz, much closer to the frequencies at which Jupiter emits (ν < 40 MHz) and lower than most previously reported observations of extrasolar planets; and (ii) sensitivities of approximately a few millijanskys have been achieved, an order of magnitude or more below nearly all previous extrasolar planet observations below 100 MHz.

Results. We do not detect any radio emissions from HD 80606b and use these observations to place new constraints on its radio luminosity. We also revisit whether the observations were conducted at a time when HD 80606b was super-Alfvénic relative to the host star’s stellar wind, which experience from the Solar System illustrates is a state in which an electron cyclotron maser emission can be sustained in a planet’s magnetic polar regions.
Phase reddening on asteroid Bennu from visible and near-infrared spectroscopy
Authors: Fornasier S. , Hasselmann P. H. , Deshapriya J. D. P , Barucci M. A. , Clark B. E. , Praet A. , Hamilton V. E. , Simon A. , Li J.-Y. , Cloutis E. A. , Merlin F. , Zou X.-D. , Lauretta D. S.
Published: November 2020

Context.The NASA mission OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer) has been observing near-Earth asteroid (101955) Bennu in close proximity since December 2018. In October 2020, the spacecraft collected a sample of surface material from Bennu to return to Earth.

Aims.In this work, we investigate spectral phase reddening – that is, the variation of spectral slope with phase angle – on Bennu using spectra acquired by the OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) covering a phase angle range of 8–130°. We investigate this process at the global scale and for some localized regions of interest (ROIs), including boulders, craters, and the designated sample collection sites of the OSIRIS-REx mission.

Methods.Spectra were wavelength- and flux-calibrated, then corrected for the out-of-band contribution and thermal emission, resampled, and finally converted into radiance factor per standard OVIRS processing. Spectral slopes were computed in multiple wavelength ranges from spectra normalized at 0.55μm.

Results.Bennu has a globally negative spectra slope, which is typical of B-type asteroids. The spectral slope gently increases in a linear way up to a phase angle of 90°, where it approaches zero. The spectral phase reddening is monotonic and wavelength-dependent with highest values in the visible range. Its coefficient is 0.00044μm−1 deg−1in the 0.55–2.5μm range. For observations of Bennu acquired at high phase angle (130°), phase reddening increases exponentially, and the spectral slope becomes positive. Similar behavior was reported in the literature for the carbonaceous chondrite Mukundpura in spectra acquired at extreme geometries. Some ROIs, including the sample collection site, Nightingale, have a steeper phase reddening coefficient than the global average, potentially indicating a surface covered by fine material with high micro-roughness.

Conclusions.The gentle spectral phase reddening effect on Bennu is similar to that observed in ground-based measurements of other B-type asteroids, but much lower than that observed for other low-albedo bodies such as Ceres or comet 67P/Churyumov-Gerasimenko. Monotonic reddening may be associated with the presence of fine particles at micron scales and/or of particles with fractal structure that introduce micro- and sub-micro roughness across the surface of Bennu.
The evolution of the gas fraction of quiescent galaxies modeled as a consequence of their creation rate
Authors: Gobat R. , Magdis G. , D’Eugenio C. , Valentino F.
Published: November 2020

We discuss the evolution of the interstellar medium of quiescent galaxies, currently emerging from recent analyses, with the help of a simple model based on well-established empirical relations such as the stellar mass functions and the main sequence of star formation. This model is meant to describe observed quantities without making specific assumptions on the nature of quenching processes, but relying on their observable consequences. We find that the high gas fractions seen or suggested at high redshift in quiescent galaxies, and their apparent mild evolution at early times, can be mostly attributed to a progenitor effect where recently quenched galaxies with ∼10% gas fractions dominate the quiescent galaxy population until z ∼ 1. In the same context, the much lower gas and dust fractions measured in local early-type galaxies are interpreted as the product of the steady depletion of their interstellar medium on a ∼2 Gyr timescale, coupled with a higher fraction of more gas-exhaustive events.
Chemical mutagenesis of a GPCR ligand: Detoxifying “inflammo-attraction” to direct therapeutic stem cell migration
Authors: Lee Jean-Pyo , Zhang Runquan , Yan Maocai , Duggineni Srinivas , Wakeman Dustin R. , Niles Walter L. , Feng Yongmei , Chen Justin , Hamblin Milton H. , Han Edward B. , Gonzalez Rodolfo , Fang Xiao , Zhu Yinsong , Wang Juan , Xu Yan , Wenger David A. , Seyfried Thomas N. , An Jing , Sidman Richard L. , Huang Ziwei , Snyder Evan Y.
Published: November 2020

Significance

While inflammatory chemokines, constitutively produced by pathologic regions, are pivotal for attracting reparative stem cells, one would certainly not want to further “inflame” a diseased brain by instilling such molecules. Exploiting the fact that receptors for such cytokines (G protein-coupled receptors [GPCR]) possess two “pockets”—one for binding, the other for signaling—we created a synthetic GPCR-agonist that maximizes interaction with the former and narrows that with the latter. Homing is robust with no inflammation. The peptide successfully directed the integration of human induced pluripotent stem cell derivatives (known to have muted migration) in a model of a prototypical neurodegenerative condition, ameliorating symptomatology.
Functional redundancy of type I and type II receptors in the regulation of skeletal muscle growth by myostatin and activin A
Authors: Lee Se-Jin , Lehar Adam , Liu Yewei , Ly Chi Hai , Pham Quynh-Mai , Michaud Michael , Rydzik Renata , Youngstrom Daniel W. , Shen Michael M. , Kaartinen Vesa , Germain-Lee Emily L. , Rando Thomas A.
Published: November 2020

Significance

Myostatin and activin A are secreted signaling molecules that act to limit skeletal muscle growth. Here, we show that myostatin and activin A utilize four receptor components to signal directly to muscle fibers. These findings have implications for strategies to target this signaling pathway for clinical applications to treat patients with muscle loss.
Towards webs of equivalence and the political nomad in agonistic debate
Authors: Bartlett Tom , Montesano Montessori Nicolina
Published: November 2020

Discourse theorists often defend their discursive stance on ‘reality’ and the material with reference to Laclau and Mouffe’s quote that, while an “earthquake or the falling of a brick…exist externally to thought,” they cannot “constitute themselves as objects outside any discursive conditions of emergence”.

While fully endorsing this statement, we argue that it does not licence discourse theorists to consider discursive formations divorced from their material context, but obliges us to account for the constraints and affordances of the material conditions on the structuring of the discursive field itself. Drawing on previous work, we argue that material conditions may render discourse systems incommensurate, such that they cannot be articulated through chains of equivalence within a radically restructured field. We suggest as a way forward the concept of the nomadic politician continually traversing between equivalential systems in order to reconfigure and renegotiate key signifiers within the materially-constrained discursive fields of each.
The (discursive) limits of (left) populism
Authors: Stavrakakis Yannis
Published: November 2020

As far as the study of (left) populism is concerned, Political Discourse Theory has been largely associated with a novel and challenging take on populist politics, first emerging in Laclau’s work in the 1970s and preoccupying Laclau, Mouffe and their co-travellers continuously since then. What has not been adequately articulated yet is what would be the limits of (left) populism as a political strategy from a discursive perspective. This short paper aims at remedying this lacuna in the relevant literature indicating certain ways forward for the discursive analysis of populism. The argument operates both at a theoretical and conceptual level as well as at the level of historical, empirical analysis.
Logics, discourse theory and methods
Authors: Glynos Jason , Howarth David , Flitcroft Ryan , Love Craig , Roussos Konstantinos , Vazquez Jimena
Published: November 2020

Logics of Critical Explanation proposed a methodological approach that could render the insights of Poststructuralist Discourse Theory (PDT) and post-Marxist political theory more conducive to critical empirical research. It also offered a language with which to counter positivist tendencies to colonize the space of methods and research strategies, showing how PDT could facilitate both explanatory and critical endeavours. Since its publication in 2007, a number of studies have applied the logics framework to empirical cases, while critically engaging with its methodological and theoretical arguments. The main purpose of this article is to evaluate some of these developments, and to set out some future challenges faced by this research programme.
“Symbolic photographs” as floating and empty signifiers
Authors: Tomanić Trivundža Ilija , Vezovnik Andreja
Published: November 2020

The article discusses the use of “symbolic photographs”  – images in news reporting which have no direct connection to
reported events – in news reporting. Such images deviate not only from the self-professed journalistic norm of factual reporting but also
fundamentally challenge the act of civic eyewitnessing constitutive for visual journalism. Concepts of floating and empty signifiers from
Discourse Theory are applied to “symbolic photographs” to analyse their ambivalent act of signification, their particular mode of iconicity
and, by extension, the journalistic and political implications of their repetitive use.
Critical fantasy studies
Authors: Glynos Jason
Published: November 2020

Many scholars have drawn attention to the affective power that aspects of discourse and practice exert in our social and political life. Fantasy is a concept that, like structures of feeling, rhetoric, myth, metaphor, and utopia, has generated illuminating explanatory and interpretive insights with which to better understand the operation of this power. In this piece I argue that there are distinctive virtues in affirming the value of the category of fantasy, from a theoretical point of view. Importantly, however, I also argue that the qualification ‘critical’ in Critical Fantasy Studies captures something about how such studies can draw out the normative, ideological, and politico-strategic implications of psychoanalytic insights and observations, and thus become part of a broader enterprise in critical theoretical and empirical research.
Moving discourse theory forward
Authors: De Cleen Benjamin , Goyvaerts Jana , Carpentier Nico , Glynos Jason , Stavrakakis Yannis
Published: November 2020

This article assesses the current state of play of the poststructuralist and post-Marxist discourse theory associated with Laclau and Mouffe and the ‘Essex school’, and identifies ways forward at the level of theory development, research practice and critique. The article starts by disentangling the different meanings of the notion of ‘discourse’ in ‘discourse theory’, clarifying the specificities of discourse theory as a theoretical and analytical framework and situating discourse theory in, but also beyond, critical discourse studies. It then moves to an assessment of the current state of discourse theory, its main contributions, and the identification of shortcomings and ways forward. This discussion is organized around five topics: methodology and the theory-analysis dialectic; the logics approach; the discursive-material relation; the role of fantasy and other psychoanalytic categories; and populism.
Politics as construction of the unthinkable
Authors: Laclau Ernesto , Liisberg Marianne , Borriello Arthur , De Cleen Benjamin
Published: November 2020

This article is the English translation of a text originally published by Ernesto Laclau in French in 1981 as part of the
proceedings of the colloquium Materialités Discursives held in Nanterre on 24–26 April 1980. In this text, Ernesto Laclau reflects on the
subject of hegemony as a discursively constructed phenomenon. Building on research on the discursive construction of the acceptability of
popular front politics in 1935 during the Seventh Congress of the Komintern, the author proposes a number of broader arguments on the notion
of antagonism and on some of the problems related to the Marxist conception of totality.
Promoting plurilingual and pluricultural competence in language learning through audiovisual translation
Authors: Baños Rocío , Marzà Anna , Torralba Gloria
Published: November 2020

The effectiveness of audiovisual translation (AVT) for language learning has been widely discussed and demonstrated by scholars in the past (cf.Lertola 2019). Nevertheless, many areas in this field of investigation are still underexplored, such as the usefulness of AVT for the acquisition of plurilingual and pluricultural competence (PPC). This is of paramount importance in the multilingual and multicultural societies we live in, and also given the emphasis the CEFRCompanion Volume(Council of Europe 2018) places on mediation and PPC. The latter has been the focus of the research project PluriTAV (2017–2019), in which the authors of this paper have taken part, aimed at developing a set of activities involving the use of AVT for the acquisition of PPC in the language classroom. This paper sets out to illustrate the theoretical framework sustaining the PluriTAV project and to reflect on the potential of AVT for the acquisition of PPC. This will be achieved by establishing links between AVT modes, transfer/mediation skills, and the descriptors developed within theFramework of Reference for Pluralistic Approaches to Languages and Cultures(FREPA) (Candelier et al. 2012), as well as referring to sample and specific activities developed within PluriTAV. In line with this project, the emphasis will be on language teaching in Higher Education, yet the discussion and the activities suggested could be easily extrapolated and adapted to other educational contexts and levels of language ability.
Who is most affected by the Corona crisis? An analysis of changes in stress and well-being in Switzerland
Authors: Kuhn Ursina , Klaas Hannah S. , Antal Erika , Dasoki Nora , Lebert Florence , Lipps Oliver , Monsch Gian-Andrea , Refle Jan-Erik , Ryser Valérie-Anne , Tillmann Robin , Voorpostel Marieke
Published: November 2020

This study analyses the consequences of the Covid-19 crisis on stress and well-being in Switzerland. In particular, we assess whether vulnerable groups in terms of social isolation, increased workload and limited socioeconomic resources are affected more than others. Using longitudinal data from the Swiss Household Panel, including a specific Covid-19 study, we estimate change score models to predict changes in perceived stress and life satisfaction at the end of the semi-lockdown in comparison to before the crisis. We find no general change in life satisfaction and a small decrease in stress. Yet, in line with our expectations, more vulnerable groups in terms of social isolation (young adults, Covid-19 risk group members, individuals without a partner), workload (women) and socioeconomic resources (unemployed and those who experienced a deteriorating financial situation) reported a decrease in life satisfaction. Stress levels decreased most strongly among high earners, workers on short-time work and the highly educated.
Regularity and uniqueness of Kelvin-Voigt models for nonhomogeneous and incompressible fluids
Authors: Antontsev S N , de Oliveira H B , Khompysh Kh
Published: November 2020

Generalized Kelvin-Voigt equations governing nonhomogeneous and incompressible fluids are considered in this work. In this work, we establish the existence of weak solutions to the considered model. Sufficient conditions ensuring more regular solutions and its uniqueness are also considered.
The research of the dynamics and the form of supercavities during separate and simultaneous motion of strikers under hydroballistic track conditions
Authors: Afanas’eva S A , Burkin V V , Diachkovskiy A S , Ischenko A N , Rogaev K S , Ju Sammel A , Sidorov A D , Chupashev A V
Published: November 2020

The research considers high-speed separate and simultaneous movement of an elongated metal strikers at supercavitation conditions. In the zone around a striker in water the high pressure area appears which makes the adjacent layers of water move. In case of a parallel high-velocity motion of a set of strikers, it is reasonable to assume the availability of the effects caused by their mutual close location.
The load exerted on a rigid wall by a highly porous cylinder during impact
Authors: Belov G V , Markov V A , Popov Yu V , Pusev V I , Selivanov V V , Frolov V V
Published: November 2020

The paper shows the directions to improve the assessment of the external load on a rigid structure during the crash of an aircraft. Our estimates describe the modeling of initial stage of impact (deformation of the nose compartment). The main goal is to evaluate the correctness and applicability of the Riera approach to mechanical equivalent of onboard equipment. Volume-perforated samples of the aluminum alloy D16T were used as mechanical equivalents in numerical and experimental studies. Both our model which uses constitutive equations of high-porous elastoplastic medium (Carroll-Holt model) and direct 3D modeling of the structure of volume-perforated samples by finite element method in the LS-DYNA allows us to obtain the history of load on a rigid wall. We demonstrate the features and differences between this approaches and the Riera approach.
Mathematical problems of calculation and optimization of composite structures
Authors: Golushko Sergey
Published: November 2020

Mathematical problems of solving direct and inverse problems of mechanics of composite structures are formulated. The problems of strength calculation and optimal design of composite overwrapped pressure vessels are investigated. The solutions of the optimization problem have been recieved and verified by solving the direct problems with obtained design parameters using the classical and improved shell theories. Numerical solutions were obtained using the spline collocation and discrete optimization methods.
Effect of nitrocellulose and 1-methyl-3-nitro-1,2,4-triazole on properties of CuO/Al and Bi2O3/Al nanothermites
Authors: Gordeev V V , Kazutin M V , Kozyrev N V
Published: November 2020

Here we examined how the addition of high-energy materials such as nitrocellulose and 1-methyl-3-nitro-1,2,4-triazole (1Me-3N) would influence the properties of Bi2O3/Al and CuO/Al nanothermite composites. The additives allowed the improvement in explosion force (F) and burning rate (u) of the composites, achieving the maxima at concentrations of 5 % NC and 9 % 1Me-3N for the Bi2O3/Al/1Me-3N mixture, and of 15 % 1Me-3N for CuO/Al/1Me-3N. A further increase in concentrations of the additives decreased the combustion performance of the composites. The effect of the said additives on the properties of nanothermite composites has been considered herein from the standpoint of a simplified model of convective burning in a single pore.
Influence of vibration excitation on the zone of laminar–turbulent transition on a plate
Authors: Grigoryev Y N , Ershov I V
Published: November 2020

Influence of thermal nonequilibrium on the laminar–turbulent transition is studied on the basis of the eN
-method for two widespread flow regimes of a supersonic boundary layer at Mach number M = 4.5. The set of actual frequencies of spatial disturbances was determined from the neutral stability curves for temporal disturbances. The families of N-factor curves were calculated for selected frequencies. The transition Reynolds number was determined for a given transition factor NT
= 8 from the envelopes of the families of N-factor curves. Calculations show that for the level of the vibrational excitation below the dissociation limit and for NT
= 8 the transition zone shifts downstream by 12÷14 % compared to a perfect gas.
The nonlinear relationship between local and macroscopic parameters of dynamic fracture in brittle composite materials
Authors: Grigoriev A S , Shilko E V
Published: November 2020

The paper describes results of a numerical study of the influence of composite structure parameters on the strength and fracture time of brittle materials under dynamic loading. The study is carried out on model concrete samples with different volume fractions of reinforcing inclusions and micropores. Simulation results show that the conventional principle of proportionality of the change in the incubation time of the fracture to the change in the linear dimensions of the fracture region is not applicable when a change in the spatial scale of the region is accompanied by a qualitative change in the parameters of the composite structure. The key factor determining the nonlinear nature of the change in the fracture incubation time during the transition from macroscale to lower scale representative volumes is the factor of phase interfaces, on which primary damage is predominantly localized. This conclusion is confirmed by much more pronounced dependence of the fracture time and dynamic strength of concrete samples on the quantitative concentration of inclusions (i.e. the characteristic distance between zirconia aggregates or micropores) than on volume fraction of inclusions.
Kinematics of the shaped charge jet formation process
Authors: Grif E M , Guskov A V , Milevskii K E
Published: November 2020

Based on the review of scientific and technical literature, an analysis is made of the problems of the modern theory of formation, extension and destruction of the shaped jet. The focus of the research is on the kinematics of the formation of a shaped jet based on the approach of operating with the characteristics of a real metal when the velocity vector of the cumulative jet is the result of three vectors: strain, strain and displacement of the shaped jet’s material. The numerical experiment of the functioning of the shaped charge is carried out, and the procedure for evaluating the calculation results is proposed. The obtained data correlate with existing knowledge about the physics of the cumulation process.
On the effect of plasma electrolytic oxidation on the fatigue strength of V96Ts1 (Al-Zn-Mg-Cu) aluminum alloy
Authors: Zakharchenko K , Kapustin V , Zverkov I , Legan M , Larichkin A , Lukianov Ya
Published: November 2020

One of the tasks of modern material science is to obtain new functional high-strength resistant coatings on structural materials like aluminum alloys. This paper shows the effect of plasma electrolytic oxidation (PEO) on the fatigue strength of V96Ts1 (Al-Zn-Mg-Cu) aluminum alloy. Fatigue tests were carried out with uniaxial loading in accordance with the harmonic law with a constant stress of 205 MPa. The modification of the PEO-coated surface layer led to a 5-fold decrease in the cyclic durability of the V96Ts1 alloy. The dependencies of the temperature of dissipative heating and the accumulated strain on the amplitude of the effective load were obtained for the inelastic cyclic strain of V96Ts alloy samples, with and without a PEO-coated surface layer. These dependencies describing material degradation correlate with the data of the fatigue tests. A fractographic analysis of the destroyed samples was also performed.
On three-dimensional boundary layer stability analysis on curved aerodynamic surfaces
Authors: Kirilovskiy S V , Boiko A V , Poplavskaya T V
Published: November 2020

Numerical simulation of three-dimensional flow past a prolate spheroid located at an angle of attack of 10° accompanied by the laminar-turbulent transition was performed for subsonic (M∞ = 0.136) and transonic (M∞ = 0.75) velocities. The general-purpose gas-dynamic package ANSYS Fluent in integration with a laminar-turbulent transition module based on software bundle LOTRAN 3 was used. The principles of numerical simulation of the main flow are discussed: requirements for the near-wall region allocation and independence of the results from various methods of presetting the position of forced turbulence. It was shown that two instability mechanisms take place in the boundary layer of the spheroid: the Tollmien-Schlichting instability and the cross-flow instability with a predominance of the last on side surfaces. A comparison of predicted position of the transition for different flow regimes was performed.
Investigation of residual stress in composites produced by explosion welding with ultrasound
Authors: Kuz’min E V , Korolev M P , Kuz’min S V , Lysak V I
Published: November 2020

The paper presents the results of experimental studies of residual stress in homogeneous steel samples obtained by explosion welding with simultaneous exposure to ultrasound. For experimental determination of residual stress in composites, a method based on sequential removal of thin metal layers from the sample surface and measurement of deformations of the sample from the opposite side using strain gages was chosen. It is shown that the introduction of ultrasound in the process of explosion welding leads to both a redistribution of residual stress and a significant decrease in their maximum values measured in the immediate vicinity of the junction zone of steel samples.
Comparative testing of MOST and Mac-Cormack numerical schemes to calculate tsunami wave propagation
Authors: Lavrentiev M , Marchuk An , Oblaukhov K , Romanenko A
Published: November 2020

The problem of fast, reliable, and accurate calculation of tsunami wave propagation is addressed. Based on the shallow water approximation, two numerical approaches to calculate tsunami wave propagation are compared at the same computational mesh. To evaluate precision of numerical solutions the available exact solutions (for the cases of sloping and parabolic bottom) are used. Results of several numerical tests are presented. Time required to obtain tsunami wave height maxima distribution is briefly discussed, too.
On the possible of the abnormally high damping effective properties of dispersion-reinforced composites and fibrous composites
Authors: Lurie S
Published: November 2020

We study the effective energy dissipation properties of solid polymer matrixes filled with coated spherical and fibrous inclusions coated with a layer of lossy viscoelastic material. The matrix and the inclusions are assumed to be separated by equal-thickness interfacial layers of a lossy viscoelastic material. We show that the remarkable loss amplification mechanism is operative in such particulate-morphology materials when the effective loss properties of composite can exceed the loss properties of the pure matrix by more than 20 times.
A mathematical model of stationary charging processes in polar dielectrics: theoretical analysis
Authors: Maksimova Nadezhda , Maslovskaya Anna
Published: November 2020

We address some global solvability issues for non-linear stationary convection-reaction-diffusion problems. Global solvability of the boundary value problem for the stationary model of a charging process of polar dielectrics under non-equilibrium external conditions is proved. The maximum principle for volume charge density is established.
One-dimensional hemodynamics in vessels with elastic walls, multicomponent approach
Authors: Mamontov Alexander , Prokudin Dmitriy
Published: November 2020

A review of hemodynamic models (blood movements in the human arterial system) is carried out taking into account the elasticity of the vessel walls. A generalization of the model is formulated regarding blood as a multicomponent medium.
On the global unique solvability of a problem for one-dimensional equations of dynamics of mixtures of viscous compressible heat-conducting fluids
Authors: Mamontov A E , Prokudin D A
Published: November 2020

One-dimensional equations of the multi-velocity model of the dynamics of mixtures of viscous compressible heat-conducting fluids and their approximation are considered. The existence and uniqueness of a strong solution to the initial-boundary value problem is proved globally in time.