scholarly journals HDO and SO2 thermal mapping on Venus

2020 ◽  
Vol 639 ◽  
pp. A69 ◽  
Author(s):  
T. Encrenaz ◽  
T. K. Greathouse ◽  
E. Marcq ◽  
H. Sagawa ◽  
T. Widemann ◽  
...  
Keyword(s):  
Local Time ◽  
Mixing Ratio ◽  
Echelle Spectrograph ◽  
Imaging Spectrometer ◽  
Infrared Telescope ◽  
Depth Ratio ◽  
Time Period ◽  
Telescope Facility ◽  
Line Depth

Since January 2012, we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). Here, we present new data recorded in February and April 2019 in the 1345 cm−1 (7.4 μm) spectral range, where SO2, CO2, and HDO (used as a proxy for H2O) transitions were observed. The cloud top of Venus was probed at an altitude of about 64 km. As in our previous studies, the volume mixing ratio (vmr) of SO2 was estimated using the SO2/CO2 line depth ratio of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2 line depth ratio, assuming a D/H ratio of 200 times the Vienna standard mean ocean water. As reported in our previous analyses, the SO2 mixing ratio shows strong variations with time and also over the disk, showing evidence for the formation of SO2 plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We have used the 2019 data in addition to our previous dataset to study the long-term variations of SO2 and H2O. The data reveal a long-term anti-correlation with a correlation coefficient of −0.80; this coefficient becomes −0.90 if the analysis is restricted to the 2014–2019 time period. The statistical analysis of the SO2 plumes as a function of local time confirms our previous result with a minimum around 10:00 and two maxima near the terminators. The dependence of the SO2 vmr with respect to local time shows a higher abundance at the evening terminator with respect to the morning. The dependence of the SO2 vmr with respect to longitude exhibits a broad maximum at 120–200° east longitudes, near the region of Aphrodite Terra. However, this trend has not been observed by other measurements and has yet to be confirmed.

scholarly journals HDO and SO2 thermal mapping on Venus

2019 ◽  
Vol 623 ◽  
pp. A70 ◽  
Author(s):  
T. Encrenaz ◽  
T. K. Greathouse ◽  
E. Marcq ◽  
H. Sagawa ◽  
T. Widemann ◽  
...  
Keyword(s):  
Local Time ◽  
Mixing Ratio ◽  
Echelle Spectrograph ◽  
Imaging Spectrometer ◽  
Infrared Telescope ◽  
Telescope Facility ◽  
The Individual ◽  
Line Depth ◽  
Uv Range

Since January 2012 we have been monitoring the behavior of sulfur dioxide and water on Venus, using the Texas Echelon Cross-Echelle Spectrograph (TEXES) imaging spectrometer at the NASA InfraRed Telescope Facility (IRTF, Mauna Kea Observatory). We present here the observations obtained between January 2016 and September 2018. As in the case of our previous runs, data were recorded around 1345 cm−1 (7.4 μm). The molecules SO2, CO2, and HDO (used as a proxy for H2O) were observed, and the cloudtop of Venus was probed at an altitude of about 64 km. The volume mixing ratio of SO2 was estimated using the SO2/CO2 line depth ratios of weak transitions; the H2O volume mixing ratio was derived from the HDO/CO2 line depth ratio, assuming a D/H ratio of 200 times the Vienna Standard Mean Ocean Water (VSMOW). As reported in our previous analyses, the SO2 mixing ratio shows strong variations with time and also over the disk, showing evidence of the formation of SO2 plumes with a lifetime of a few hours; in contrast, the H2O abundance is remarkably uniform over the disk and shows moderate variations as a function of time. We performed a statistical analysis of the behavior of the SO2 plumes, using all TEXES data between 2012 and 2018. They appear mostly located around the equator. Their distribution as a function of local time seems to show a depletion around noon; we do not have enough data to confirm this feature definitely. The distribution of SO2 plumes as a function of longitude shows no clear feature, apart from a possible depletion around 100E–150E and around 300E–360E. There seems to be a tendency for the H2O volume mixing ratio to decrease after 2016, and for the SO2 mixing ratio to increase after 2014. However, we see no clear anti-correlation between the SO2 and H2O abundances at the cloudtop, neither on the individual maps nor over the long term. Finally, there is a good agreement between the TEXES results and those obtained in the UV range (SPICAV/Venus Express and UVI/Akatsuki) at a slightly higher altitude. This agreement shows that SO2 observations obtained in the thermal infrared can be used to extend the local time coverage of the SO2 measurements obtained in the UV range.

scholarly journals Precise Near-Infrared Radial Velocities

2015 ◽  
Vol 10 (S314) ◽  
pp. 286-287
Author(s):  
Peter Plavchan ◽  
Peter Gao ◽  
Jonathan Gagne ◽  
Elise Furlan ◽  
Carolyn Brinkworth ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Near Infrared ◽  
M Dwarfs ◽  
Gas Cell ◽  
Methane Absorption ◽  
Infrared Telescope ◽  
Telescope Facility ◽  
Nasa Infrared Telescope Facility ◽  
Modeling Code

AbstractWe present the results of two 2.3 μm near-infrared (NIR) radial velocity (RV) surveys to detect exoplanets around 36 nearby and young M dwarfs. We use the CSHELL spectrograph (R ~ 46,000) at the NASA InfraRed Telescope Facility (IRTF), combined with an isotopic methane absorption gas cell for common optical path relative wavelength calibration. We have developed a sophisticated RV forward modeling code that accounts for fringing and other instrumental artifacts present in the spectra. With a spectral grasp of only 5 nm, we are able to reach long-term radial velocity dispersions of ~20–30 m s−1 on our survey targets.

scholarly journals The H 3 + ionosphere of Uranus: decades-long cooling and local-time morphology

2019 ◽  
Vol 377 (2154) ◽  
pp. 20180408 ◽  
Author(s):  
Henrik Melin ◽  
L. N. Fletcher ◽  
T. S. Stallard ◽  
S. Miller ◽  
L. M. Trafton ◽  
...  
Keyword(s):  
Local Time ◽  
Near Infrared ◽  
Molecular Ions ◽  
Upper Atmosphere ◽  
Infrared Observations ◽  
Infrared Telescope ◽  
Telescope Facility ◽  
Nasa Infrared Telescope Facility ◽  
Cooling Trend

The upper atmosphere of Uranus has been observed to be slowly cooling between 1993 and 2011. New analysis of near-infrared observations of emission from H 3 + obtained between 2012 and 2018 reveals that this cooling trend has continued, showing that the upper atmosphere has cooled for 27 years, longer than the length of a nominal season of 21 years. The new observations have offered greater spatial resolution and higher sensitivity than previous ones, enabling the characterization of the H 3 + intensity as a function of local time. These profiles peak between 13 and 15 h local time, later than models suggest. The NASA Infrared Telescope Facility iSHELL instrument also provides the detection of a bright H 3 + signal on 16 October 2016, rotating into view from the dawn sector. This feature is consistent with an auroral signal, but is the only of its kind present in this comprehensive dataset. This article is part of a discussion meeting issue ‘Advances in hydrogen molecular ions: H 3 + , H 5 + and beyond’.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

scholarly journals Sociolinguistic Markers of Friendship Among Persons With Dementia in Long-Term Care

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 575-575
Author(s):  
Pamela Saunders
Keyword(s):  
Social Interaction ◽  
Long Term Care ◽  
Ethnographic Study ◽  
Linguistic Features ◽  
Term Care ◽  
Socially Constructed ◽  
Time Period ◽  
Pronominal Reference ◽  
Field Notes

Abstract Sociolinguistics and discourse analysis provide tools through which to examine how friendship is socially constructed through language and communication. Research on social isolation and loneliness reveals the importance of social interaction on the psychological and physical health of older adults. Given that linguistic, communicative, and functional abilities decline as dementia progresses, it is challenging to identify markers of friendship. The Friendship Project is an ethnographic study of social interaction among persons with dementia living in a long-term care setting. The data are from transcripts and field-notes of social interactions among residents with a range of cognitive impairments over a six-month time period. Results reveal that persons with dementia employ specific linguistic features such as narrative, evaluation, evidentials, and pronominal reference to make meaning and create relationships over time. Practical implications will be discussed.

scholarly journals Long-Term Concrete Shrinkage Influence on the Performance of Reinforced Concrete Structures

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 254
Author(s):  
Alinda Dey ◽  
Akshay Vijay Vastrad ◽  
Mattia Francesco Bado ◽  
Aleksandr Sokolov ◽  
Gintaris Kaklauskas
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Structures ◽  
Tension Stiffening ◽  
Model Code ◽  
Concrete Shrinkage ◽  
Time Period ◽  
Governing Factor ◽  
Model Code 2010 ◽  
Mathematical Process

The contribution of concrete to the tensile stiffness (tension stiffening) of a reinforced concrete (RC) member is a key governing factor for structural serviceability analyses. However, among the current tension stiffening models, few consider the effect brought forth by concrete shrinkage, and none studies take account of the effect for very long-term shrinkage. The present work intends to tackle this exact issue by testing multiple RC tensile elements (with different bar diameters and reinforcement ratios) after a five-year shrinking time period. The experimental deformative and tension stiffening responses were subjected to a mathematical process of shrinkage removal aimed at assessing its effect on the former. The results showed shrinkage distinctly lowered the cracking load of the RC members and caused an apparent tension stiffening reduction. Furthermore, both of these effects were exacerbated in the members with higher reinforcement ratios. The experimental and shrinkage-free behaviors of the RC elements were finally compared to the values predicted by the CEB-fib Model Code 2010 and the Euro Code 2. Interestingly, as a consequence of the long-term shrinkage, the codes expressed a smaller relative error when compared to the shrinkage-free curves versus the experimental ones.

ON THE CONSUMPTION/DISTRIBUTION THEOREM UNDER THE LONG-RUN GROWTH CRITERION SUBJECT TO A DRAWDOWN CONSTRAINT

2010 ◽  
Vol 13 (06) ◽  
pp. 931-957 ◽  
Author(s):  
MICHAEL J. KLASS ◽  
KRZYSZTOF NOWICKI
Keyword(s):  
Growth Rate ◽  
Short Term ◽  
Long Run ◽  
Time Period ◽  
Total Capital ◽  
Growth Criterion ◽  
Drawdown Constraint ◽  
Riskless Asset ◽  
Distribution Theorem

Consider any discrete time sequence of investment fortunes Fn which has a finite long-run growth rate [Formula: see text] when subject to the present value capital drawdown constraint Fne-rn ≥ λ* max 0≤k≤nFke-rk, where 0 ≤ λ* < 1, in the presence of a riskless asset affording a return of er dollars per time period per dollar invested. We show that money can be withdrawn for consumption from the invested capital without either reducing the long-run growth rate of such capital or violating the drawdown constraint for our capital sequence, while simultaneously increasing the amount of capital withdrawn for consumption at the identical long-term rate of V(r, λ*). We extend this result to an exponentially increasing number of consumption categories and discuss how additional yearly contributions can temporarily augment the total capital under management. In addition, we assess the short-term practicality of creating such an endowment/consumption/distribution program.

Long-term Safety and Efficacy of Mexiletine in Myotonic Dystrophy Types 1 and 2

2021 ◽  
pp. 10.1212/CPJ.0000000000001073
Author(s):  
Christina Mousele ◽  
Emma Matthews ◽  
Robert Pitceathly ◽  
Michael Hanna ◽  
Susan McDonald ◽  
...  
Keyword(s):  
Myotonic Dystrophy ◽  
Sodium Channels ◽  
Genetic Disorders ◽  
Clinical Feature ◽  
Efficacy And Safety ◽  
Voltage Gated Sodium Channels ◽  
Time Period ◽  
Mean Time

AbstractBackground:Myotonic dystrophy types 1 and 2 are progressive multisystem genetic disorders, whose core clinical feature is myotonia. Mexiletine, an antagonist of voltage-gated sodium channels, is a recommended anti-myotonic agent in the non-dystrophic myotonias, but its use in myotonic dystrophy is limited due to lack of data regarding its long-term efficacy and safety profile.Methods:To address this issue, this study retrospectively evaluated patients with myotonic dystrophy receiving mexiletine over a mean time-period of 32.9 months (range 0.1 to 216 months).Results:This study demonstrated that 96% of patients reported some improvement in myotonia symptoms with mexiletine treatment. No clinically relevant cardiac adverse events were associated with the long-term use of mexiletine.Conclusions:These findings support that mexiletine is both safe and effective when used long-term in myotonic dystrophy.Classification of Evidence:This study provides class IV evidence that mexiletine is a well-tolerated and effective treatment for myotonic dystrophy types 1 and 2.

Space Infrared Telescope Facility (SIRTF) Science Instruments

1988 ◽  
Author(s):  
R Ramos ◽  
S. M. Hing ◽  
C. A. Leidich ◽  
G. Fazio ◽  
J R. Houck ◽  
...  
Keyword(s):  
Infrared Telescope ◽  
Telescope Facility ◽  
Infrared Telescope Facility
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