scholarly journals Multi-scale measurements of mesospheric aerosols and electrons during the MAXIDUSTY campaign

2019 ◽  
Vol 12 (4) ◽  
pp. 2139-2153
Author(s):  
Tarjei Antonsen ◽  
Ove Havnes ◽  
Andres Spicher
Keyword(s):  
Cloud System ◽  
Sounding Rocket ◽  
Small Scale ◽  
Plasma Parameters ◽  
Multi Scale ◽  
System A ◽  
Power Spectral ◽  
Good Agreement ◽  
Strong Spin

Abstract. We present in situ measurements of small-scale fluctuations in aerosol populations as recorded through a mesospheric cloud system from the Faraday cups DUSTY and MUDD during on the MAXIDUSTY-1 and 1B sounding rocket payloads launched in the summer of 2016. Two mechanically identical DUSTY probes mounted with an inter-spacing of ∼10 cm recorded very different currents, with strong spin modulation, in certain regions of the cloud system. A comparison to auxiliary measurement show similar tendencies in the MUDD data. Fluctuations in the electron density are found to be generally anti-correlated to the negative aerosol charge density on all length scales; however, in certain smaller regions the correlation turns positive. We have also compared the spectral properties of the dust fluctuations, as extracted by wavelet analysis, to polar mesospheric summer echo (PMSE) strength. In this analysis, we find a relatively good agreement between the power spectral density (PSD) at the radar Bragg scale inside the cloud system; however the PMSE edge is not well represented by the PSD. A comparison of proxies for PMSE strength, constructed from a combination of derived dusty plasma parameters, shows that no simple proxy can reproduce PMSE strength well throughout the cloud system. Edge effects are especially poorly represented by the proxies addressed here.

scholarly journals Multi-scale Measurements of Mesospheric Aerosols and Electrons During the MAXIDUSTY Campaign

2018 ◽  
Author(s):  
Tarjei Antonsen ◽  
Ove Havnes ◽  
Andres Spicher
Keyword(s):  
Spectral Properties ◽  
Cloud System ◽  
Small Scale ◽  
Plasma Parameters ◽  
Multi Scale ◽  
System A ◽  
Spin Modulation ◽  
Power Spectral ◽  
Good Agreement ◽  
Strong Spin

Abstract. We present measurements of small scale fluctuations in aerosol populations as recorded through a mesospheric cloud system by the Faraday cups DUSTY and MUDD during the MAXIDUSTY-1B flight on the 8th of July, 2016. Two mechanically identical DUSTY probes mounted with an inter-spacing of ~ 10 cm, recorded very different currents, with strong spin modulation, in certain regions of the cloud system. A comparison to auxiliary measurement show similar tendencies in the MUDD data. Fluctuations in the electron density are found to be generally anti-correlated on all length scales, however, in certain smaller regions the correlation turns positive. We have also compared the spectral properties of the dust fluctuations, as extracted by wavelet analysis, to PMSE strength. In this analysis, we find a relatively good agreement between the power spectral density (PSD) at the radar Bragg scale inside the cloud system, however the PMSE edge is not well represented by the PSD. A comparison of proxies for PMSE strength, constructed from a combination of derived dusty plasma parameters, show that no simple proxy can reproduce PMSE strength well throughout the cloud system. Edge effects are especially poorly represented by the proxies addressed here.

scholarly journals Simultaneous in situ measurements of small-scale structures in neutral, plasma, and atomic oxygen densities during WADIS sounding rocket project

2019 ◽  
Author(s):  
Boris Strelnikov ◽  
Martin Eberhart ◽  
Martin Friedrich ◽  
Jonas Hedin ◽  
Mikhail Khaplanov ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Atomic Oxygen ◽  
Density Fluctuations ◽  
Sounding Rocket ◽  
Small Scale ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Mlt Region ◽  
Diffusion Properties

Abstract. In this paper we present an overview of measurements conducted during the WADIS-2 rocket campaign. We investigate the effect of small-scale processes like gravity waves and turbulence on the distribution of atomic oxygen and other species in the MLT region. Our analysis suggests that density fluctuations of atomic oxygen are coupled to fluctuations of other constituents, i.e., plasma and neutrals. Our measurements show that all measured quantities, including winds, densities, and temperatures, reveal signatures of both waves and turbulence. We show observations of gravity wave saturation and breakdown together with simultaneous measurements of generated turbulence. Atomic oxygen inside turbulence layers shows two different spectral behaviors, which might imply change of its diffusion properties.

scholarly journals Feasibility Study and Demonstration of an Aluminum and Ice Solid Propellant

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Timothee L. Pourpoint ◽  
Tyler D. Wood ◽  
Mark A. Pfeil ◽  
John Tsohas ◽  
Steven F. Son
Keyword(s):  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Sounding Rocket ◽  
Small Scale ◽  
Solid Propellants ◽  
Aluminum Particles ◽  
Underwater Propulsion ◽  
Binary Formulation

Aluminum-water reactions have been proposed and studied for several decades for underwater propulsion systems and applications requiring hydrogen generation. Aluminum and water have also been proposed as a frozen propellant, and there have been proposals for other refrigerated propellants that could be mixed, frozen in situ, and used as solid propellants. However, little work has been done to determine the feasibility of these concepts. With the recent availability of nanoscale aluminum, a simple binary formulation with water is now feasible. Nanosized aluminum has a lower ignition temperature than micron-sized aluminum particles, partly due to its high surface area, and burning times are much faster than micron aluminum. Frozen nanoscale aluminum and water mixtures are stable, as well as insensitive to electrostatic discharge, impact, and shock. Here we report a study of the feasibility of an nAl-ice propellant in small-scale rocket experiments. The focus here is not to develop an optimized propellant; however improved formulations are possible. Several static motor experiments have been conducted, including using a flight-weight casing. The flight weight casing was used in the first sounding rocket test of an aluminum-ice propellant, establishing a proof of concept for simple propellant mixtures making use of nanoscale particles.

scholarly journals Reconstruction of the Parker spiral with the Reverse In situ data and MHD APproach - RIMAP

2020 ◽  
Author(s):  
Ruggero Biondo ◽  
Alessandro Bemporad ◽  
Andrea Mignone ◽  
Fabio Reale
Keyword(s):  
Interplanetary Medium ◽  
Small Scale ◽  
Reconstruction Technique ◽  
The Sun ◽  
Plasma Parameters ◽  
In Situ Data ◽  
Mhd Simulations ◽  
Solar Eruptions ◽  
In Situ Observations

The reconstruction of plasma parameters in the interplanetary medium is very important to understand the interplanetary propagation of solar eruptions and for Space Weather application purposes. Because only a few spacecraft are measuring in situ these parameters, reconstructions are currently performed by running complex numerical Magneto-hydrodynamic (MHD) simulations starting from remote sensing observations of the Sun. Current models apply full 3D MHD simulations of the corona or extrapolations of photospheric magnetic fields combined with and semiempirical relationships to derive the plasma parameters on a sphere centered on the Sun (inner boundary). The plasma is then propagated in the interplanetary medium up to the Earth’s orbit and beyond. Nevertheless, this approach requires significant theoretical and computational efforts, and the results are only in partial agreement with the in situ observations. In this paper we describe a new approach to this problem called RIMAP - Reverse In situ data and MHD APproach. The plasma parameters in the inner boundary at 0.1 AU are derived directly from the in situ measurements acquired at 1 AU, by applying a back reconstruction technique to remap them into the inner heliosphere. This remapping is done by using the Weber and Davies solar wind theoretical model to reconstruct the wind flowlines. The plasma is then re-propagated outward from 0.1 AU by running a MHD numerical simulation based on the PLUTO code. The interplanetary spiral reconstructions obtained with RIMAP are not only in a much better agreement with the in situ observations, but are also including many more small-scale longitudinal features in the plasma parameters that are not reproduced with the approaches developed so far.

PMWE creation mechanism inferred from sounding rocket measurements

2021 ◽  
Author(s):  
Boris Strelnikov ◽  
Keyword(s):  
Electron Density ◽  
Current Knowledge ◽  
Sounding Rocket ◽  
Small Scale ◽  
Sounding Rockets ◽  
Smoke Particles ◽  
The North ◽  
Air Turbulence ◽  
Rocket Measurements

<p>A first sounding rocket campaign dedicated to investigate the creation mechanism of Polar Mesosphere Winter Echoes (PMWE) was conducted in April 2018 from the north Norwegian Andøya Space Center (69°N, 16°E). Two instrumented sounding rockets were launched on 13th and 18th of April under PMWE and no-PMWE conditions, respectively.</p><p>In this paper we give a brief summary of our current knowledge of PMWE and an overview of the PMWE sounding rocket mission. We describe and discuss some results of combined in situ and ground-based measurements which allow <span>to</span> <span>check</span> the existing PMWE theories.</p><p>Our measurements clearly show that the coherent structures in refractive index variations (forming PMWE) are accompanied by neutral air turbulence, which is reflected in small-scale structures (down to some meters) of neutral and electron density. We show that the behavior of the structures under investigation together with the atmospheric background is consistent with the interpretation, that PMWE were created by turbulence. Rocket measurements ultimately show that polar winter mesosphere is abounded with meteor smoke particles (MSP) and intermittent turbulent layers. Furthermore, it becomes clear that charged Meteor Smoke Particles (MSP) and background electron density can only enhance SNR, while turbulence is a prerequisite for their formation.</p>

scholarly journals Simultaneous in situ measurements of small-scale structures in neutral, plasma, and atomic oxygen densities during the WADIS sounding rocket project

2019 ◽  
Vol 19 (17) ◽  
pp. 11443-11460 ◽  
Author(s):  
Boris Strelnikov ◽  
Martin Eberhart ◽  
Martin Friedrich ◽  
Jonas Hedin ◽  
Mikhail Khaplanov ◽  
...  
Keyword(s):  
Atomic Oxygen ◽  
Lower Thermosphere ◽  
Density Fluctuations ◽  
Sounding Rocket ◽  
Small Scale ◽  
Scale Structures ◽  
Small Scale Structures ◽  
Mlt Region ◽  
Diffusion Properties

Abstract. In this paper we present an overview of measurements conducted during the WADIS-2 rocket campaign. We investigate the effect of small-scale processes like gravity waves and turbulence on the distribution of atomic oxygen and other species in the mesosphere–lower thermosphere (MLT) region. Our analysis suggests that density fluctuations of atomic oxygen are coupled to fluctuations of other constituents, i.e., plasma and neutrals. Our measurements show that all measured quantities, including winds, densities, and temperatures, reveal signatures of both waves and turbulence. We show observations of gravity wave saturation and breakdown together with simultaneous measurements of generated turbulence. Atomic oxygen inside turbulence layers shows two different spectral behaviors, which might imply a change in its diffusion properties.

Development of an In-Situ Curemeter

1993 ◽  
Vol 66 (1) ◽  
pp. 83-91
Author(s):  
A. N. Gent ◽  
Kefu Xie
Keyword(s):  
Mold Wall ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Small Scale ◽  
Theoretical Treatment ◽  
Rubber Compound ◽  
Loss Angle ◽  
Rubber Compounds ◽  
Good Agreement

Abstract An in-situ curemeter has been developed to follow the cure of thick articles during molding, by measuring continuously the dynamic mechanical properties (shear modulus and loss angle). It is a small-scale version of the Oscillating Disk Rheometer, designed to operate through the mold wall. An approximate theoretical treatment has been developed to relate the observed torque and loss angle to the dynamic properties of the rubber compound. Experiments were carried out with both unfilled and carbon-black-filled natural rubber compounds. Cure times measured by the curemeter were about the same as those obtained with the Oscillating Disk Rheometer. Modulus values inferred from the measured torques were compared with directly-measured values obtained from load-deflection curves for fully-cured specimens. Good agreement was found.

Atomic Layer Deposition of LiF and Lithium Ion Conducting (AlF3)(LiF)x Alloys Using Trimethylaluminum, Lithium Hexamethyldisilazide and Hydrogen Fluoride

2017 ◽  
Author(s):  
Younghee Lee ◽  
Daniela M. Piper ◽  
Andrew S. Cavanagh ◽  
Matthias J. Young ◽  
Se-Hee Lee ◽  
...  
Keyword(s):  
Lithium Ion ◽  
Atomic Layer ◽  
Mass Gain ◽  
Alloy Film ◽  
Ex Situ ◽  
X Ray ◽  
Layer Deposition ◽  
Ion Conducting ◽  
Good Agreement

<div>Atomic layer deposition (ALD) of LiF and lithium ion conducting (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloys was developed using trimethylaluminum, lithium hexamethyldisilazide (LiHMDS) and hydrogen fluoride derived from HF-pyridine solution. ALD of LiF was studied using in situ quartz crystal microbalance (QCM) and in situ quadrupole mass spectrometer (QMS) at reaction temperatures between 125°C and 250°C. A mass gain per cycle of 12 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C and decreased at higher temperatures. QMS detected FSi(CH<sub>3</sub>)<sub>3</sub> as a reaction byproduct instead of HMDS at 150°C. LiF ALD showed self-limiting behavior. Ex situ measurements using X-ray reflectivity (XRR) and spectroscopic ellipsometry (SE) showed a growth rate of 0.5-0.6 Å/cycle, in good agreement with the in situ QCM measurements.</div><div>ALD of lithium ion conducting (AlF3)(LiF)x alloys was also demonstrated using in situ QCM and in situ QMS at reaction temperatures at 150°C A mass gain per sequence of 22 ng/(cm<sup>2</sup> cycle) was obtained from QCM measurements at 150°C. Ex situ measurements using XRR and SE showed a linear growth rate of 0.9 Å/sequence, in good agreement with the in situ QCM measurements. Stoichiometry between AlF<sub>3</sub> and LiF by QCM experiment was calculated to 1:2.8. XPS showed LiF film consist of lithium and fluorine. XPS also showed (AlF<sub>3</sub>)(LiF)x alloy consists of aluminum, lithium and fluorine. Carbon, oxygen, and nitrogen impurities were both below the detection limit of XPS. Grazing incidence X-ray diffraction (GIXRD) observed that LiF and (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film have crystalline structures. Inductively coupled plasma mass spectrometry (ICP-MS) and ionic chromatography revealed atomic ratio of Li:F=1:1.1 and Al:Li:F=1:2.7: 5.4 for (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film. These atomic ratios were consistent with the calculation from QCM experiments. Finally, lithium ion conductivity (AlF<sub>3</sub>)(LiF)<sub>x</sub> alloy film was measured as σ = 7.5 × 10<sup>-6</sup> S/cm.</div>

scholarly journals Upscaling THM modeling from small-scale to full-scale in-situ experiments in the Callovo-Oxfordian claystone

2021 ◽  
Vol 144 ◽  
pp. 104582
Author(s):  
D.M. Seyedi ◽  
C. Plúa ◽  
M. Vitel ◽  
G. Armand ◽  
J. Rutqvist ◽  
...  
Keyword(s):  
Full Scale ◽  
Small Scale ◽  
In Situ Experiments
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