Entry Conditions in Planetary Atmospheres: Emission Spectroscopy of Molecular Plasma Arcjets

2001 ◽  
Vol 15 (2) ◽  
pp. 168-175 ◽  
Author(s):  
V. Lago ◽  
A. Lebehot ◽  
M. Dudeck ◽  
S. Pellerin ◽  
T. Renault ◽  
...  
Keyword(s):  
Emission Spectroscopy ◽  
Planetary Atmospheres ◽  
Molecular Plasma

scholarly journals HNCO-based synthesis of formamide in planetary atmospheres

2018 ◽  
Vol 616 ◽  
pp. A150 ◽  
Author(s):  
M. Ferus ◽  
V. Laitl ◽  
A. Knizek ◽  
P. Kubelík ◽  
J. Sponer ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Fourier Transform ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Emission Spectroscopy ◽  
Planetary Atmospheres ◽  
Infrared Emission ◽  
Ab Initio Molecular Dynamics ◽  
Isocyanic Acid ◽  
Dynamics Simulations

Time-resolved Fourier transform infrared emission spectroscopy, Fourier transform absorption infrared spectroscopy, and high-resolution UV–ViS emission spectroscopy have been used to characterize the chemistry of isocyanic acid (HNCO) under glow discharge conditions in planetary atmospheres. HNCO mixtures (i.e., composed of di-hydrogen or ammonia) have been investigated in order to unveil the possible reaction pathways leading to the synthesis of the key prebiotic molecule formamide (HCONH2), upon planetary atmospheres containing isocyanic acid in presence of di-hydrogen and, separately, of ammonia. In addition, ab initio molecular dynamics simulations coupled with a modern metadynamics technique have been performed in order to identify the most likely chemical pathways connecting HNCO to formamide. It turned out that the direct hydrogenation of HNCO is thermodynamically favored. Incidentally, the experimental results – supplied by a simplified kinetic model – also proved the favorability of the reaction HNCO + H2→ HCONH2which, moreover, spontaneously takes place in unbiased ab initio molecular dynamics simulations carried out under the effect of intense electric fields.

Signal/Noise Ratio and Elemental Detectivity by Eels

1982 ◽  
Vol 40 ◽  
pp. 488-489
Author(s):  
R. F. Egerton
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Elemental Analysis ◽  
Electron Energy Loss Spectroscopy ◽  
Emission Spectroscopy ◽  
X Ray ◽  
Signal Noise ◽  
Characteristic Signal ◽  
Noise Ratio ◽  
Electron Energy Loss

An important parameter governing the sensitivity and accuracy of elemental analysis by electron energy-loss spectroscopy (EELS) or by X-ray emission spectroscopy is the signal/noise ratio of the characteristic signal.

Infrared Emission Spectroscopy as a Reliability Tool

1999 ◽  
Author(s):  
Q. Kim ◽  
S. Kayali
Keyword(s):  
Spatial Resolution ◽  
Emission Spectroscopy ◽  
Hot Spot ◽  
Cost Effective ◽  
Infrared Emission ◽  
Test System ◽  
Operating Conditions ◽  
Yield Enhancement ◽  
Infrared Emission Spectroscopy ◽  
Channel Temperature

Abstract In this paper, we report on a non-destructive technique, based on IR emission spectroscopy, for measuring the temperature of a hot spot in the gate channel of a GaAs metal/semiconductor field effect transistor (MESFET). A submicron-size He-Ne laser provides the local excitation of the gate channel and the emitted photons are collected by a spectrophotometer. Given the state of our experimental test system, we estimate a spectral resolution of approximately 0.1 Angstroms and a spatial resolution of approximately 0.9 μm, which is up to 100 times finer spatial resolution than can be obtained using the best available passive IR systems. The temperature resolution (<0.02 K/μm in our case) is dependent upon the spectrometer used and can be further improved. This novel technique can be used to estimate device lifetimes for critical applications and measure the channel temperature of devices under actual operating conditions. Another potential use is cost-effective prescreening for determining the 'hot spot' channel temperature of devices under normal operating conditions, which can further improve device design, yield enhancement, and reliable operation. Results are shown for both a powered and unpowered MESFET, demonstrating the strength of our infrared emission spectroscopy technique as a reliability tool.

scholarly journals Breathing in the Anthropocene: Thinking Through Scale with Containment Technologies

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
Alison Kenner ◽  
Aftab Mirzaei ◽  
Christy Spackman
Keyword(s):  
Potato Chip ◽  
Human Agency ◽  
Building Design ◽  
Planetary Atmospheres ◽  
Atmospheric Process ◽  
Advanced Capitalism ◽  
Significant Burden ◽  
Insight Into

Thinking at the scale of the Anthropocene highlights the significant burden on all life imposed by the residues of industrialization as well as continued pollution. But it also risks a disconnect between the functioning of planetary atmospheres and the functioning of local airs. In this thought-piece, we consider together the potato chip bag, the asthma inhaler, and climate positive building design as scalar practices of Anthropocene air. By figuring Anthropocene air as an interscalar vehicle, we show connections between matter and relations that seem distant and disconnected. We do this by honing in on respiration as a transformative atmospheric process that has been designed in advanced capitalism to extend life for some, while denying life for others. We point to seconds, hours, days, weeks, and seasons to highlight how containment technologies and respiratory processes function in the Anthropocene to remake air. These technologies and practices, which all too often go unnoticed in consumption landscapes, demonstrate that despite Anthropocene air’s tendency to exceed human agency, it is liable to engineering. Doing this offers insight into where different scales of action can be mobilized.

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