scholarly journals Characterization of exoplanetary atmospheres through a model-unbiased spectral survey methodology

2021 ◽  
Vol 657 ◽  
pp. A36
Author(s):  
A. Lira-Barria ◽  
P. M. Rojo ◽  
R. A. Mendez
Keyword(s):  
Spectral Line ◽  
Survey Methodology ◽  
Noise Levels ◽  
Relative Absorption ◽  
Successful Technique ◽  
Exoplanetary Atmospheres ◽  
Spectral Survey ◽  
Archive Data

Context. Collecting a large variety of exoplanetary atmosphere measurements is crucial to improve our understanding of exoplanets. In this context, it is likely that the field would benefit from broad species surveys, particularly using transit spectroscopy, which is the most successful technique of exoplanetary atmosphere characterization so far. Aims. Our goal is to develop a model-unbiased technique using transit spectroscopy to analyze every qualified atomic spectral line in exoplanetary transit data, and search for relative absorption, that is, a decrease in the flux of the line when the planet is transiting. Methods. We analyzed archive data from HDS at Subaru, HIRES at Keck, UVES at VLT, and HARPS at LaSilla to test our spectral survey methodology. It first filtered individual lines by relative noise levels. It also corrected for spectral offsets and telluric contamination. Our methodology performed an analysis along time and wavelength. The latter employed a bootstrap corroboration. Results. We highlight the possible detections of Mn I and V II in HD 209459b data taken by HDS at Subaru (5.9σ at 5916.4 Å, 5.1σ at 6021.8 Å). The previous detection of Ca I in the same planet is classified as inconclusive by our algorithm, but we support the previous detection of Sc II (3.5σ at 6604.6 Å). We also highlight the possible detection of Ca I, Sc II, and Ti II in HD 189733 data taken by UVES at VLT (4.4σ at 6572.8 Å, 6.8σ at 6604.6 Å, and 3.5σ at 5910.1 Å), in addition to the possible detection of Al I in WASP-74b data taken by UVES at VLT (5.6σ at 6696.0 Å).

scholarly journals Characterization of Noise Level Inside a Vehicle under Different Conditions

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2471 ◽  
Author(s):  
Daniel Flor ◽  
Danilo Pena ◽  
Luan Pena ◽  
Vicente A. de Sousa ◽  
Allan Martins
Keyword(s):  
Regression Analysis ◽  
Noise Level ◽  
Acoustic Noise ◽  
Experimental Setup ◽  
Strongly Correlated ◽  
Noise Levels ◽  
Noise Sources ◽  
Statistical Tools ◽  
Window Position

Vehicular acoustic noise evaluations are a concern of researchers due to health and comfort effects on humans and are fundamental for anyone interested in mitigating audio noise. This paper focuses on the evaluation of the noise level inside a vehicle by using statistical tools. First, an experimental setup was developed with microphones and a microcomputer located strategically on the car’s panel, and measurements were carried out with different conditions such as car window position, rain, traffic, and car speed. Regression analysis was performed to evaluate the similarity of the noise level from those conditions. Thus, we were able to discuss the relevance of the variables that contribute to the noise level inside a car. Finally, our results revealed that the car speed is strongly correlated to interior noise levels, suggesting the most relevant noise sources are in the vehicle itself.

An expert opinion survey on post-hazard restoration of roadways and bridges: Data and key insights

2020 ◽  
Vol 36 (2) ◽  
pp. 983-1004
Author(s):  
Sushreyo Misra ◽  
Jamie E Padgett ◽  
Andre R Barbosa ◽  
Bret M Webb
Keyword(s):  
Online Survey ◽  
Natural Hazard ◽  
Survey Methodology ◽  
Risk And Resilience ◽  
Opinion Survey ◽  
Bridge Inspection ◽  
Multiple Hazards ◽  
Time Required ◽  
Expert Opinion Survey

This article presents the data collected through an online survey of experts in the field of roadway and bridge inspection and repair, with an aim to understand and characterize post-hazard restoration timelines. Accurate characterization of natural hazard resilience of a community requires a thorough understanding of the restoration process. However, empirical data are lacking to systematically relate damage induced by multiple hazards to functionality for both roadways and bridges. Existing models, relying on survey data which are tailored for seismic damage to bridges, either fail to capture the entire restoration timeline or do not account for intermediate stages of restoration. To address these gaps, an online survey of experts eliciting recommended traffic closures and the estimated time required to remove traffic closures/partial restrictions is presented herein. This article contains a detailed description of the survey methodology with insights into the data collected from a total of 29 respondents to enable its use in the area of transportation infrastructure risk and resilience analysis under natural hazards.

Observation of the Berreman Effect in Infrared Reflection-Absorption Spectra of Amorphous Titanium Oxide Thin Films Deposited on Aluminum

2000 ◽  
Vol 54 (5) ◽  
pp. 687-691 ◽  
Author(s):  
B. C. Trasferetti ◽  
C. U. Davanzo ◽  
N. C. da Cruz ◽  
M. A. B. de Moraes
Keyword(s):  
Thin Films ◽  
Absorption Spectra ◽  
Optical Constants ◽  
Polarized Light ◽  
Chemical Vapor ◽  
Layered System ◽  
Infrared Reflection ◽  
Fresnel Equation ◽  
Successful Technique

Infrared reflection-absorption spectra of plasma-enhanced chemical vapor deposition (PECVD) amorphous TiO2 thin films on aluminum were obtained with s- and p-polarized light and oblique incidence angles. Such spectra were analyzed by means of spectral simulations based on a Fresnel equation for a three-layered system. The optical constants used in the simulations were obtained through the Kramers–Krönig analysis of the reflectance spectra of a pellet of powdered amorphous TiO2. LO-TO energy-loss functions were also calculated from these optical constants, and a splitting was observed. A good qualitative agreement between experimental and simulated spectra was achieved, and the Berreman effect was observed in both cases when p-polarized light was used. It was shown, therefore, that the Berreman effect makes infrared reflection-absorption spectroscopy a successful technique for the characterization of an amorphous TiO2 thin layer on aluminum.

Diagnostic characterization of a prepulsed carbon fiber Z pinch using spectral line intensity analyses

1999 ◽  
Vol 70 (2) ◽  
pp. 1425-1429 ◽  
Author(s):  
A. Lorenz ◽  
N. J. Peacock ◽  
M. G. O’Mullane ◽  
David Neely
Keyword(s):  
Carbon Fiber ◽  
Spectral Line ◽  
Line Intensity ◽  
Spectral Line Intensity ◽  
Z Pinch

Characterization of a Pt-Ne hollow cathode spectral line source

1990 ◽  
Vol 29 (19) ◽  
pp. 2951 ◽  
Author(s):  
Jules Z. Klose ◽  
George F. Hartig ◽  
William J. Rosenberg
Keyword(s):  
Spectral Line ◽  
Hollow Cathode ◽  
Line Source

scholarly journals Noise Pollution Analysis of Reserved Areas: Case Study of the Isparta Ayazmana Promenade Area

2021 ◽  
pp. 10-18
Author(s):  
Candan Kus Sahin ◽  
Busra Onay ◽  
Beyza Sava
Keyword(s):  
City Planning ◽  
Survey Methodology ◽  
Noise Pollution ◽  
Survey Study ◽  
Noise Levels ◽  
City Center ◽  
Open Spaces ◽  
Sporting Activities

The sustainable landscpe design is a strategic framework in city planning and urban recreational areas, important for the quality of life of an increasingly urbanized society. This study deals with a better understanding of visitors demand and noise properties of Ayazmana promenade area, located in Isparta city center, Turkiye. The approach in the study is an exploration one with a base in site observations, interviews and survey. However, the average noise levels of the area was measured between 43.1 to 58.1 dB(A) in Autumn and 50.2 to 62.0 dB(A) in Spring, respectively. The recreational characteristics of Ayazmana promenade area were further evaluated with survey methodology on total of 100 respondents. Moreover, majority of participants (79) reported to be visiting of that promenade area for cheating with friends, followed by 78 for traveling, 70 for walking, 65 for sitting in green open spaces and for picnic, 57 for listening music and 53 for sporting activities, respectively. It is noticeable that most of the respondents (92%) were described the Ayazmana promenade area is somewhat noisy. At the end of survey study, it was requested to assessed the Ayazmana promenade area with some suggestions by respondents.

scholarly journals Diagnostic Characterization of Laser-Irradiated dot Targets

1988 ◽  
Vol 102 ◽  
pp. 375-378
Author(s):  
G. Charatis ◽  
G.E. Busch ◽  
B.K.F. Young ◽  
R.E. Stewart
Keyword(s):  
Steady State ◽  
Spectral Line ◽  
Holographic Interferometry ◽  
Line Ratio ◽  
X Ray ◽  
Preliminary Results ◽  
Spatial Gradients ◽  
Simultaneous Measurements ◽  
Series Of Experiments

AbstractWe have conducted a series of experiments at the KMS CHROMA facility using dot spectroscopy techniques to characterize uncertainties associated with spectral line ratio models commonly applied in determining electron temperatures and densities. Temperatures determined from the slope of the H-like free-bound continuum and densities via holographic interferometry, are compared to line ratio methods. Dot targets of (typically 100µmD Mg or Al) are irradiated with 2 to 40 × 1013W/cm2of 0.53µmlight. Time and spatial gradients are resolved using 4 diagnostics: a 4-frame holographic interferometer, an x-ray streak crystal spectrograph with a spatial imaging slit, a framing crystal x-ray spectrometer, and a conventional space-resolved time-integrating crystal spectrograph used for survey and calibration purposes. Preliminary results indicate the ionization distribution of these laser produced plasmas is not steady-state which plays an important role in measuring the temperature and and density. Electron temperatures derived from line-ratio techniques, assuming steady state conditions, disagree dramatically from simultaneous measurements using the slope of the H-like continuum. Electron densities using He-like triplet to singlet line ratios also differ from densities measured interferometrically.

scholarly journals An optical transmission spectrum of the ultra-hot Jupiter WASP-33 b

2019 ◽  
Vol 622 ◽  
pp. A71 ◽  
Author(s):  
C. von Essen ◽  
M. Mallonn ◽  
L. Welbanks ◽  
N. Madhusudhan ◽  
A. Pinhas ◽  
...  
Keyword(s):  
Light Curves ◽  
Atmospheric Composition ◽  
Data Sets ◽  
Hot Jupiters ◽  
High Data ◽  
Trace Species ◽  
Exoplanetary Atmospheres ◽  
Combined Data ◽  
Hot Jupiter

There has been increasing progress toward detailed characterization of exoplanetary atmospheres, in both observations and theoretical methods. Improvements in observational facilities and data reduction and analysis techniques are enabling increasingly higher quality spectra, especially from ground-based facilities. The high data quality also necessitates concomitant improvements in models required to interpret such data. In particular, the detection of trace species such as metal oxides has been challenging. Extremely irradiated exoplanets (~3000 K) are expected to show oxides with strong absorption signals in the optical. However, there are only a few hot Jupiters where such signatures have been reported. Here we aim to characterize the atmosphere of the ultra-hot Jupiter WASP-33 b using two primary transits taken 18 orbits apart. Our atmospheric retrieval, performed on the combined data sets, provides initial constraints on the atmospheric composition of WASP-33 b. We report a possible indication of aluminum oxide (AlO) at 3.3-σ significance. The data were obtained with the long slit OSIRIS spectrograph mounted at the 10-m Gran Telescopio Canarias. We cleaned the brightness variations from the light curves produced by stellar pulsations, and we determined the wavelength-dependent variability of the planetary radius caused by the atmospheric absorption of stellar light. A simultaneous fit to the two transit light curves allowed us to refine the transit parameters, and the common wavelength coverage between the two transits served to contrast our results. Future observations with HST as well as other large ground-based facilities will be able to further constrain the atmospheric chemical composition of the planet.

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