Влияние семантики локализованности на текстовую внешнетемпоральную транспозицию

Языковая временная семантика в лингвистических исследованиях последних лет рассматривается как широкая сфера языковых/речевых отношений различных категорий (грамматических, функционально- семантических, текстовых), т.е. как область пересечения, иногда концентрации аспектуального, собственно темпорального, таксисного и другого аналогичного содержания, где центральное место принадлежит глагольной единице, потенциальные функциональные возможности которой и определяют указанные грамматические отношения

The Dynamics of CO 2 ‐Driven Granular Flows in Gullies on Mars

Martian gullies are landforms consisting of an erosional alcove, a channel, and a depositional apron. A significant proportion of Martian gullies at the mid‐latitudes is active today. The seasonal sublimation of CO2 ice has been suggested as a driver behind present‐day gully activity. However, due to a lack of in situ observations, the actual processes causing the observed changes remain unresolved. Here, we present results from flume experiments in environmental chambers in which we created CO2‐driven granular flows under Martian atmospheric conditions. Our experiments show that under Martian atmospheric pressure, large amounts of granular material can be fluidized by the sublimation of small quantities of CO2 ice in the granular mixture (only 0.5% of the volume fraction of the flow) under slope angles as low as 10°. Dimensionless scaling of the CO2‐driven granular flows shows that they are dynamically similar to terrestrial two‐phase granular flows, that is, debris flows and pyroclastic flows. The similarity in flow dynamics explains the similarity in deposit morphology with levees and lobes, supporting the hypothesis that CO2‐driven granular flows on Mars are not merely modifying older landforms, but they are actively forming them. This has far‐reaching implications for the processes thought to have formed these gullies over time. For other planetary bodies in our solar system, our experimental results suggest that the existence of gully like landforms is not necessarily evidence for flowing liquids but that they could also be formed or modified by sublimation‐driven flow processes

A new challenge for meteorological measurements: The meteoMet project-Metrology for meteorology

Climate change and its consequences require immediate actions in order to safeguard the environment and economy in Europe and in the rest of world. Aiming to enhance data reliability and reduce uncertainties in climate observations, a joint research project called MeteoMet-Metrology for Meteorology started in October 2011 coordinated by the Italian Istituto Nazionale di Ricerca Metrologica (INRiM). The project is focused on the traceability of measurements involved in climate change: surface and upper air measurements of temperature, pressure, humidity, wind speed and direction, solar irradiance and reciprocal influences between measurands. This project will provide the first definition at the European level of validated climate parameters with associated uncertainty budgets and novel criteria for interpretation of historical data series. The big challenge is the propagation of a metrological measurement perspective to meteorological observations. When such an approach will be adopted the requirement of reliable data and robust datasets over wide scales and long terms could be better met. © 2013 AIP Publishing LLC

Experimental Wind Characterization with the SuperCam Microphone under a Simulated martian Atmosphere

Located on top of the mast of the Mars 2020 Perseverance rover, the SuperCam instrument suite includes a microphone to record audible sounds from 100 Hz to 10 kHz on the surface of Mars. It will support SuperCam’s Laser-Induced Breakdown Spectroscopy investigation by recording laser-induced shock-waves but it will also record aeroacoustic noise generated by wind flowing past the microphone. This experimental study was conducted in the Aarhus planetary wind-tunnel under low CO2 pressure with wind generated at several velocities. It focused on understanding the wind-induced acoustic signal measured by microphones instrumented in a real scale model of the rover mast as a function of the wind speed and wind orientation. Acoustic spectra recorded under a wind flow show that the low-frequency range of the microphone signal is mainly influenced by the wind velocity. In contrast, the higher frequency range is seen to depend on the wind direction relative to the microphone. On the one hand, for the wind conditions tested inside the tunnel, it is shown that the Root Mean Square of the pressure, computed over the 100 Hz to 500 Hz frequency range, is proportional to the dynamic pressure. Therefore, the SuperCam microphone will be able to estimate the wind speed, considering an in situ cross-calibration with the Mars Environmental Dynamic Analyzer. On the other hand, for a given wind speed, it is observed that the root mean square of the pressure, computed over the 500 Hz to 2000 Hz frequency range, is at its minimum when the microphone is facing the wind whereas it is at its maximum when the microphone is pointing downwind. Hence, a full 360° rotation of the mast in azimuth in parallel with sound recording can be used to retrieve the wind direction. We demonstrate that the SuperCam Microphone has a priori the potential to determine both the speed and the direction of the wind on Mars, thus contributing to atmospheric science investigations

AVIATR - Aerial Vehicle for In-situ and Airborne Titan Reconnaissance A Titan Airplane Mission Concept

We describe a mission concept for a stand-alone Titan airplane mission: Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR). With independent delivery and direct-to-Earth communications, AVIATR could contribute to Titan science either alone or as part of a sustained Titan Exploration Program. As a focused mission, AVIATR as we have envisioned it would concentrate on the science that an airplane can do best: exploration of Titan's global diversity. We focus on surface geology/hydrology and lower-atmospheric structure and dynamics. With a carefully chosen set of seven instruments-2 near-IR cameras, 1 near-IR spectrometer, a RADAR altimeter, an atmospheric structure suite, a haze sensor, and a raindrop detector-AVIATR could accomplish a significant subset of the scientific objectives of the aerial element of flagship studies. The AVIATR spacecraft stack is composed of a Space Vehicle (SV) for cruise, an Entry Vehicle (EV) for entry and descent, and the Air Vehicle (AV) to fly in Titan's atmosphere. Using an Earth-Jupiter gravity assist trajectory delivers the spacecraft to Titan in 7.5 years, after which the AVIATR AV would operate for a 1-Earth-year nominal mission. We propose a novel 'gravity battery' climb-then-glide strategy to store energy for optimal use during telecommunications sessions. We would optimize our science by using the flexibility of the airplane platform, generating context data and stereo pairs by flying and banking the AV instead of using gimbaled cameras. AVIATR would climb up to 14 km altitude and descend down to 3.5 km altitude once per Earth day, allowing for repeated atmospheric structure and wind measurements all over the globe. An initial Team-X run at JPL priced the AVIATR mission at FY10 $715M based on the rules stipulated in the recent Discovery announcement of opportunity. Hence we find that a standalone Titan airplane mission can achieve important science building on Cassini's discoveries and can likely do so within a New Frontiers budget

Modelling the Effect of Electrification on Volcanic Ash Aggregation

The fine ash released into the atmosphere (particles 200 µm). Besides providing a theoretical framework to quantify the effect of charge, our findings demonstrate that aggregation models that do not account for electrification significantly underestimate the amount of fine ash that sediments in the form of aggregates, leading to an overestimation of the residence time of fine ash in the atmosphere after explosive volcanic eruptions

Experimental simulations of volcanic ash resuspension by wind under the effects of atmospheric humidity

Ash deposited during volcanic eruptions can be resuspended by wind and become hazardous for health and infrastructure hours to decades after an eruption. Accurate resuspension forecasting requires accurate modelling of the threshold friction velocity of the volcanic particles (Uth*), which is the key parameter controlling volcanic ash detachment by wind. Using an environmental wind tunnel facility this study provides much needed experimental data on volcanic particle resuspension, with the first systematic parameterization of Uth* for ash from the regions Campi Flegrei in Italy and also Eyjafjallajökull in Iceland. In this study atmospheric relative humidity (and related ash moisture content) was systematically varied, from 90%, which in the case of the Eyjafjallajökull fine ash (<63 μm) produced a twofold increase in Uth*. Using the Campi Flegrei fine ash (<63 μm) an increase in Uth* of only around a factor of 1.5 was observed. Reasonable agreement with force balance resuspension models was seen, which implied an increase in interparticle adhesion force of up to a factor of six due to high humidity. Our results imply that, contrary to dry conditions, one single modelling scheme may not satisfy the resuspension of volcanic ash from different eruptions under wet conditions.Funded by Europlanet 2020 RI under the European Union’s Horizon 2020 research and innovation programme and grant agreement No 654208, Conv. INGV-DPC B2 2016 - Centro di Pericolosità Vulcanica, and by the Marie Curie Initial Training Network ‘VERTIGO’, funded through the European Seventh Framework Programme (FP7 2007–2013) under Grant Agreement number 607905. Optical granunlometry, SEM and Helium Pycnometer analyses are from HP-HT Laboratories of Experimental Volcanology and Geophysics at INGV- Roma.Published145095V. Processi eruttivi e post-eruttivi6V. Pericolosità vulcanica e contributi alla stima del rischioJCR Journa

Stability of volcanic ash aggregates and break-up processes

Numerical modeling of ash plume dispersal is an important tool for forecasting and mitigating potential hazards from volcanic ash erupted during explosive volcanism. Recent tephra dispersal models have been expanded to account for dynamic ash aggregation processes. However, there are very few studies on rates of disaggregation during transport. It follows that current models regard ash aggregation as irrevocable and may therefore overestimate aggregation-enhanced sedimentation. In this experimental study, we use industrial granulation techniques to artificially produce aggregates. We subject these to impact tests and evaluate their resistance to break-up processes. We find a dependence of aggregate stability on primary particle size distribution and solid particle binder concentration. We posit that our findings could be combined with eruption source parameters and implemented in future tephra dispersal models