Approaches for Monitoring Warfighter Blast-related Exposures in Training to Develop Effective Safety Standards

ABSTRACT Introduction Traumatic brain injuries are of concern to the sports and military communities because of the age of the participants and costly burden to society. To markedly reduce the impact of traumatic brain injury and its sequela (TBI-S), it is necessary to determine the initial vulnerability of individuals as well as identify new technologies that indicate early signs of TBI-S. Materials and Methods Currently, diverse methods have been used by the authors and others in laboratory settings to reveal early signs of persistent TBI-S including simulation modeling of the effect of rapid deceleration on the deviatoric strain (shear force) imposed on specific brain regions, auditory evoked potential (AEP) measurements to determine injury to the auditory cortex optokinetic nystagmus (OKN) measures sensitive to vestibular trauma, and optical coherence tomography (OCT) measures that reveal changes in central visual function obtained noninvasively by examination of the retina. Results Simulation studies provided technical information on maximal deviatoric strain at the base of the sulci and interface of gray and white matter consistent with results from neuropathology and from magnetic resonance imaging. The AEP and OKN reveal measurable injury to similar regions below the Sylvian fissure including auditory cortex and midbrain, and the OCT reveals changes to the retina consistent with forceful deceleration effects. Conclusions The studies and results are consistent with prior work demonstrating that noninvasive tests may be sensitive to the presence of TBI-S, potentially in the training field as advances in the portability of test instruments are underway. When combined with baseline data gathered from individuals in quantitative form, key variances can emerge. Therefore, it is hypothesized that AEP, OKN, and OCT, taken together, may yield faster objective and quantitative neurophysiological measures serving as a “signature” of neural injury and more indicative of potentially persistent TBI-S—recommending larger scale longitudinal studies.

Mechanisms and predictability of sudden stratospheric warming in winter 2018

In the beginning of February 2018 a rapid deceleration of the westerly circulation in the polar Northern Hemisphere stratosphere took place, and on 12 February the zonal-mean zonal wind at 60∘ N and 10 hPa reversed to easterly in a sudden stratospheric warming (SSW) event. We investigate the role of the tropospheric forcing in the occurrence of the SSW, its predictability and teleconnection with the Madden–Julian oscillation (MJO) by analysing the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble forecast. The SSW was preceded by significant synoptic wave activity over the Pacific and Atlantic basins, which led to the upward propagation of wave packets and resulted in the amplification of a stratospheric wavenumber 2 planetary wave. The dynamical and statistical analyses indicate that the main tropospheric forcing resulted from an anticyclonic Rossby wave breaking, subsequent blocking and upward wave propagation in the Ural Mountains region, in agreement with some previous studies. The ensemble members which predicted the wind reversal also reasonably reproduced this chain of events, from the horizontal propagation of individual wave packets to upward wave-activity fluxes and the amplification of wavenumber 2. On the other hand, the ensemble members which failed to predict the wind reversal also failed to properly capture the blocking event in the key region of the Urals and the associated intensification of upward-propagating wave activity. Finally, a composite analysis suggests that teleconnections associated with the record-breaking MJO phase 6 observed in late January 2018 likely played a role in triggering this SSW event.

The Relationship between Bus Drivers’ Improper Driving Behaviors and Abnormal Vehicle States Based on Advanced Driver Assistance Systems in Naturalistic Driving

In order to improve the adaptation of driver to the advanced driver assistance system (ADAS) and optimize the active safety control technology of vehicle under man-computer cooperative driving, this paper investigated the correlation between driver’s improper driving behaviors and abnormal vehicle states under the ADAS. Based on the warning data collected from the driver’s assistance warning system equipped on buses, the interaction between improper behaviors, between abnormal vehicle states, and between improper behaviors and abnormal vehicle states were quantitatively analyzed through the hierarchical clustering method and improved Apriori algorithm. The results showed that eye closure and yawn were high in concurrency (probability: 0.888) and interaction (average probability: 0.946); the interaction among lane departure, rapid acceleration, and rapid deceleration are frequent (average probability: 0.7224); eye closure (average probability: 0.452) and yawn (average probability: 0.444) are likely to induce abnormal vehicle states such as rapid acceleration and rapid deceleration. Some suggestions proposed based on the results are as follows. First, it is suggested that the ADAS should combine the warning modes of eye closure and yawn; second, when the driver closes eyes or yawns, the control of the ADAS over the lateral and longitudinal performance of vehicle should be enhanced; third, the extent of control by the ADAS should be determined according to the relationship probability; finally, the lateral control over the vehicle by the ADAS should be strengthened when there is a forward collision warning.

Analysis of the performance of electrodynamic tethers with autonomous electron generation

Currently, electric rocket engines have largely reached the efficiency limits determined by the principle of rocket thrust. Electrodynamic tethers, interacting with an external magnetic field and actually being jet engines, are devoid of such restrictions. However, their thrust is limited by the concentration of the external plasma and depends on its fluctuations. The paper is the first to propose to create a current in the tether by propellant ionization, receiving a large thrust from a relatively short tether and a strong magnetic field deflecting charged cosmic particles. The numerical analysis showed that the length of the tether of hundreds of meters near the Earth provides a specific impulse of up to hundreds of kilometers per second and its proper acceleration of the power plant at a level of 0.01 m / s2, as well as protection of the central region of the tether from particles with an energy of more than 1 MeV. This makes it possible to consider it for maneuvering satellites with practically no restrictions on the delta-V, for performing fast high-energy inter-orbital flights and for radiation protection of a high-latitude orbital station. In the future, such a tether can be used for rapid deceleration of orbital objects, launching into geostationary orbit, interplanetary transfers and protection of objects from charged particles. The study describes possible areas of application and directions for further research of the concept of such a tether.

FORECAST OF TEMPERATURE ANOMALIES IN EUROPE AND RUSSIA BY THEIR CORRELATION WITH CHANGES IN THE EARTH'S ROTATION SPEED

The article provides information about the relationship between changes in the global temperature on the Earth and variations in the speed of its rotation. Special attention is paid to the study of the correlation between the onset of abnormal warm and cold winters of the Eurasian continent and sharp changes in the Earth's rotation speed. It been observed, that during periods of rapid deceleration in the 20th and 21st century, there were abnormally cold winters, and during periods of acceleration, abnormally warm ones. Thus, the periods of acceleration and deceleration of the Earth's rotation speed fell respectively on warm or cold winters in all cases, except for the winter of 1964/65 g., when the Earth's rotation occurred relatively evenly. Based on the obtained 90 % correlation of the number of coincidences of anamal winters with sharp changes in the speed of EW, as well as the calculated forecast of the Earth's rotation speed up to 2030, it is concluded that from 2024 to 2026 g, anamol cold winter should be expected in Russia and Europe

FLASHING: New high-velocity H2O masers in IRAS 18286−0959

We discovered new high-velocity components of H2O maser emission in one of the “water fountain” sources, IRAS 18286−0959, which has been monitored using the Nobeyama 45 m telescope in the FLASHING (Finest Legacy Acquisitions of SiO- and H2O-maser Ignitions by Nobeyama Generation) project since 2018 December. The maser spectra show new components with extremely high expansion velocities (>200 km s−1 projected in the line of sight), some of which are located symmetrically in the spectrum with respect to the systemic velocity. They were also mapped with KaVA (KVN and VERA Combined Array) in 2019 March. We located some of these maser components closer to the central stellar system than other high-velocity components (50–200 km s−1) that have been confirmed to be associated with the known bipolar outflow. The new components would have flashed in the fast collimated jet at a speed of over 300 km s−1 (soon) after 2011 when they had not been detected. The fastest of the new components seem to indicate rapid deceleration in these spectra; however, our present monitoring is still too sparse to unambiguously confirm it (up to 50 km s−1 yr−1) and too short to reveal their terminal expansion velocity, which will be equal to the expansion velocity that has been observed ($v$exp ∼ 120 km s−1). Future occurrences of such extreme-velocity components may provide a good opportunity to investigate possible recurrent outflow ignitions. Thus, the sculpture of the parental envelope will be traced by the dense gas that is entrained by the fast jet and exhibits spectacular distributions of the relatively stable maser features.

Mechanisms and predictability of Sudden Stratospheric Warming in winter 2018

In the beginning of February 2018 a rapid deceleration of the westerly circulation in the polar Northern Hemisphere stratosphere took place and on 12 February the zonal mean zonal wind at 60° N and 10 hPa reversed to easterly in a Sudden Stratospheric Warming (SSW) event. We investigate the role of the tropospheric forcing in the occurrence of the SSW, its predictability and teleconnection with the Madden-Julian oscillation (MJO) by analysing the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble forecast. The SSW was preceded by significant synoptic wave activity over the Pacific and Atlantic basins, which led to the upward propagation of wave packets and resulted in the amplification of a stratospheric wavenumber 2 planetary wave. The dynamical and statistical analyses indicate that the main tropospheric forcing resulted from an anticyclonic Rossby wave breaking, subsequent blocking and upward wave propagation in the Ural Mountains region, in agreement with some previous studies. The ensemble members which predicted the wind reversal, also reasonably reproduced this chain of events, from the horizontal propagation of individual wave packets to upward wave activity fluxes and the amplification of wavenumber 2. On the other hand, the ensemble members which failed to predict the wind reversal, also failed to properly capture the blocking event in the key region of the Urals and the associated intensification of upward propagating wave activity. Finally, a composite analysis suggests that teleconnections associated with the record-breaking MJO phase 6 observed in the late January 2018 likely played a role in triggering this SSW event.

#ALL versus ALL in American Sign Language (ASL)

This paper extends a visible pattern (‘iconicity’) that has been observed in sign language verbs and adjectives to quantification in American Sign Language (ASL). The Event Visibility Hypothesis (EVH) states that boundedness is morphophonologically encoded in articulation of a rapid deceleration of movement at the end of a sign (aka end-marking). Here the EVH is applied to the two ASL quantifiers glossed #ALL and ALL. Doing so accounts for the semantic distinction between them: ALL is definite (bounded), whereas #ALL is underspecified for definiteness (unbounded).

Formation of detrital clay grain coats by dewatering of deep-water sands and significance for reservoir quality

ABSTRACT Well-developed detrital clay grain coats are observed in deep-marine sandstones of the Upper Cretaceous Springar Formation of the Vøring Basin in the Norwegian Sea. The detrital clay coats form thin and compact rims on individual sand grains and meniscus-shaped bridges between grains. These well-developed coats are found in high-density turbidites and proximal hybrid event beds with common to pervasive dewatering structures deposited in proximity to the base of a syndepositionally active basin high. Here, in one exploration well, detrital clay grain coats are common throughout a sandstone package 100 m thick. High-density turbidites and proximal and distal hybrid event beds drilled in mid- to distal-fan settings unaffected by seismically resolved seafloor topography show common dewatering features, but have only scattered detrital clay coats confined to individual dewatering pipes or dish structures. Hence, we propose that intense sediment dewatering has the potential to form detrital clay coats in deep-marine sandstones by a combination of elutriation and reorganization of clays during fluid escape from sediment bodies with pore fluid pressures significantly higher than the hydrostatic pressure. In submarine fan systems, deposition of sediment with coeval trapping of large volumes of interstitial pore fluid is most likely to occur where gravity flows undergo rapid deceleration in response to an abrupt decrease in confinement or gradient. Such environments include the channel–lobe transition and settings in proximity to seabed topography. The investigated sandstones are quartz arenites and subarkoses, with minor to moderate volumes of quartz cement (up to 6%). However, strongly to completely quartz-cemented intergranular pore space is observed where detrital clay coats or matrix does not cover quartz grains in the deepest part of the studied formation. Modeling of quartz cementation predicts that most intergranular macroporosity in the lower part of the Springar Formation would be quartz cemented if the sandstones were free of detrital clays. Based on our observations and modeling results we propose that intense sediment dewatering has the potential to form detrital clay coats, which can be important for retaining porosity in deeply buried sandstones and in basins with high present or past heat flow.