108 research outputs found
Electrophysiological Brain-Cardiac Coupling in Train Drivers during Monotonous Driving
Electrophysiological research has previously investigated monotony and the cardiac health of drivers independently; however, few studies have explored the association between the two. As such the present study aimed to examine the impact of monotonous train driving (indicated by electroencephalogram (EEG) activity) on an individual's cardiac health as measured by heart rate variability (HRV). Sixty-three train drivers participated in the present study, and were required to complete a monotonous train driver simulator task. During this task, a 32 lead EEG and a three-lead electrocardiogram were recorded from each participant. In the present analysis, the low (LF) and high frequency (HF) HRV parameters were associated with delta (p < 0.05), beta (p = 0.03) and gamma (p < 0.001) frequency EEG variables. Further, total HRV was associated with gamma activity, while sympathovagal balance (i.e., LF:HF ratio) was best associated fronto-temporal delta activity (p = 0.02). HRV and EEG parameters appear to be coupled, with the parameters of the delta and gamma EEG frequency bands potentially being the most important to this coupling. These relationships provide insight into the impact of a monotonous task on the cardiac health of train drivers, and may also be indicative of strategies employed to combat fatigue or engage with the driving task
Electric-Field-Induced Mott Insulating States in Organic Field-Effect Transistors
We consider the possibility that the electrons injected into organic
field-effect transistors are strongly correlated. A single layer of acenes can
be modelled by a Hubbard Hamiltonian similar to that used for the
kappa-(BEDT-TTF)(2)X family of organic superconductors. The injected electrons
do not necessarily undergo a transition to a Mott insulator state as they would
in bulk crystals when the system is half-filled. We calculate the fillings
needed for obtaining insulating states in the framework of the slave-boson
theory and in the limit of large Hubbard repulsion, U. We also suggest that
these Mott states are unstable above some critical interlayer coupling or
long-range Coulomb interaction.Comment: 9 pages, 7 figure
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Deportation Stigma and Re-migration
Many, if not most, of those who are forcibly expelled from the country to which they have migrated will not settle in the country to which they have been returned but will leave again. A recent article examined some of the reasons why this should be so. It was argued that in addition to the factors that had caused the original migration, such as fear of persecution, continuing conflict, insecurity, poverty and lack of opportunity, deportation creates at least three additional reasons that make re-migration the most likely outcome. These were debt, family commitments and the shame of failure and or ‘contamination’ leading to stigmatisation. In this article, we explore the stigma of failure and of contamination attached to those deported, and the ways in which they respond to and manage this stigmatisation, including by re-migrating. We use Goffman's concept of stigma and the refinement offered by to further nuance understanding of the impact of deportation
Chitosan-Based Polyelectrolyte Complex in Combination with Allotropic Forms of Carbon as a Basis for Thin-Film Organic Electronics
Received: 30.05.2024. Revised: 11.06.2024. Accepted: 19.06.2024. Available online: 28.06.2024.Samples of a new polymer composite material based on a PEC doped with various allotropic forms of carbon were prepared.Based on the films studied, field-effect transistors were created and their output and transfer characteristics were measured.If a combination of both GO and SWCNT is incorporated into the nanocomposite, the mobility of carriers increases sharply.Using atomic force microscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy, the morphology and mobility of charge carriers in composite films with a thickness of no more than 500 nm obtained on the basis of a polyelectrolyte complex of chitosan and chitosan succinamide with addition of particles of carbon materials were studied and estimated. The following carbon materials were used: single-walled carbon nanotubes, graphene oxide, and carbon-containing sorbents with different specific surfaces (Carboblack C and Carbopack). Moreover, the studied materials in the form of films were used as a transport layer in the structure of field-effect transistors. The output and transfer characteristics of the transistors obtained were measured. According to the measurement results, the mobility of charge carriers, μ, ranges from 0.341 to 1.123 cm2 V–1·s–1, depending on the type of carbon material added. The best result was demonstrated by films based on a composite containing simultaneously single-walled carbon nanotubes and graphene oxide (μ = 10.972 cm2 V–1·s–1).This work was supported by the Ministry of Science and Higher Education of the Russian Federation (scientific code FZWU-2023-0002) and by the Russian Science Foundation (Grant № 23-73-00119), https://rscf.ru/project/23-73-00119/
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Gangster in guerilla face: A transnational mirror of production between the USA and El Salvador
Doble cara (double/two-faced) is a key trope in Salvadoran political folklore. It is a folk theory of mimesis, which attempts to 'master the absent presence of the other' through a discourse of conspiracy. The term has a history in the US-funded Salvadoran civil war. In this article, I consider how doble cara has come to be deployed around a new and pivotal social subject - Salvadoran immigrant gang youth deported from the USA - and how these deported youth emerge as a packed and displaced sign for the trauma of post-civil war violence, the failed promise of peace, and ongoing entanglements between the USA and El Salvador. The article is written in conversation with Begoña Aretxaga, who inspired many of the questions explored here. Copyright © 2007 SAGE Publications
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Fools banished from the Kingdom: Remapping geographies of gang violence between the Americas (Los Angeles and San Salvador)
Spectroscopy and Dynamics of Jet-Cooled Styrene-Ammonia Clusters
Author Institution: The Hebrew University of Jerusalem, Jerusalem, IsraelThe absorption and emission spectra of styrene have been analyzed with the help of an ab-initio calculation. It was found that out-of-plane vibrations undergo, in general, a red shift upon electronic excitation, while in-plane ones are not appreciably changed. An important exception to this rule is the mode, which is similar the mode of benzene - it shows a considerable frequency increase upon excitation. The analysis led to some new assignments of certain vibronic transitions. In addition, the spectra of styrene-ammonia adducts were recorded. Cluster formation affects the frequencies of some normal modes of to a small but easily measured extent. It was found that in general, out-of-plane modes were blue shifted with respect to the bare molecule, while in-plane modes were essentially unchanged. Vibronic bands leading to out-of-plane in the cluster appear to be less intense than in the bare molecule; in contrast, some bands at about are found to have a considerably more intense than the corresponding bare molecule ones. These bands are due to a mode similar to the mode of benzene, responsible for the vibronic coupling that makes the transition weakly allowed. The dissociation energy of the styrene-ammonia cluster was roughly determined, by recording the dispersed emission spectra following excitation of the cluster to different vibronic levels. It was found to be for and for
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