scholarly journals Infrared spectroscopy of the merger candidate KIC 9832227

2018 ◽  
Vol 615 ◽  
pp. A120 ◽  
Author(s):  
Ya. V. Pavlenko ◽  
A. Evans ◽  
D. P. K. Banerjee ◽  
J. Southworth ◽  
M. Shahbandeh ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Binary Star ◽  
Circumstellar Envelope ◽  
Stellar Rotation ◽  
Coronal Activity ◽  
Orbital Phase ◽  
Solar Metallicity ◽  
Contact Binary ◽  
The Individual

Context. It has been predicted that the object KIC 9832227 – a contact binary star – will undergo a merger in 2022.2 ± 0.7. We describe the near-infrared (NIR) spectrum of this object as an impetus to obtain pre-merger data. Aims. We aim to characterise (i) the nature of the individual components of the binary and (ii) the likely circumbinary environment, so that the merger – if and when it occurs – can be interpreted in an informed manner. Methods. We use infrared (IR) spectroscopy in the wavelength range 0.7–2.5 μm, to which we fit model atmospheres to represent the individual stars. We use the binary ephemeris to determine the orbital phase at the time of observation. Results. We find that the IR spectrum is best fitted by a single component with effective temperature 5920 K, log[g] = 4.1, and solar metallicity, consistent with the fact that the system was observed at conjunction. Conclusions. The strength of the IR H lines is consistent with a high value of logg, and the strength of the Ca II triplet indicates the presence of a chromosphere, as might be expected from rapid stellar rotation. The He I absorption we observe likely arises in He excited by coronal activity in a circumstellar envelope, suggesting that the weakness of the Ca II triplet is also likely chromospheric in origin.

scholarly journals Near-Infrared Adaptive Optics Spectroscopy of Binary Brown Dwarfs HD 130948B and HD 130948C

2003 ◽  
Vol 211 ◽  
pp. 269-270
Author(s):  
M Goto ◽  
A.T. Tokunaga ◽  
M. Cushing ◽  
D. Potter ◽  
N. Kobayashi ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Binary System ◽  
Adaptive Optics ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Brown Dwarfs ◽  
Brown Dwarf ◽  
Low Mass ◽  
The Individual

We present near-infrared spectroscopy of low-mass companions in the HD 130948 system (Goto et al. 2002a). Adaptive optics on the Subaru Telescope allowed for spectroscopy of the individual components of the 0″.13 binary system. Based on a direct comparison with a series of template spectra, we determined the spectral types of HD 130948B and C to be L4 ± 1. We find they are most likely a binary brown dwarf system.

Near-infrared spectroscopy: rapid and effective tool for measuring fructose content

2021 ◽  
Vol 67 (1) ◽  
pp. 3259-3268
Author(s):  
Haruna Gado Yakubu ◽  
Zoltán Kovács ◽  
Flóra Vitális ◽  
György Bázár
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Health Risks ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Fructose Intake ◽  
High Fructose ◽  
The Individual ◽  
Analytical Technology ◽  
Detection And Quantification

Since high fructose intake was found to be associated with increased health risks, it is important to raise awareness towards the amount of this widely used sugar within foods and beverages. The rapid and accurate detection and quantification of sugar types is not an easy task using conventional laboratory technologies. Near-infrared (NIR) spectroscopy has been proven to be a useful tool in this regard, and the present study highlights the applicability of this rapid correlative analytical technology in the measurement of fructose concentration against that of other sugars in aqueous solutions of sweeteners. The presented NIR calibrations are accurate for the relative measure of °Brix (R2 = 0.84), and the direct measurement of the individual sugars (R2 > 0.90) even in solutions with multiple sugars.

Infrared Spectra of Cured and Uncured Rubbers

1959 ◽  
Vol 32 (2) ◽  
pp. 628-638
Author(s):  
G. A. Blokh ◽  
A. F. Mal'nev
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared ◽  
Infrared Absorption Spectrum ◽  
Infrared Region ◽  
Absorption Bands ◽  
Linear Absorption ◽  
Infrared Rays ◽  
Other Substances ◽  
The Individual

Abstract The newest physical-chemical methods of research enlarge the scope of study of the vulcanization process. There is a possibility of studying the structure changes during vulcanization of rubber by the application of infrared spectroscopy. Infrared rays are selectively absorbed. Therefore the infrared absorption spectrum can be used as a characteristic property of a substance and could be used for analytical purposes. The large spectral range of the infrared rays indicates their importance for the study of the properties and structure of substances; this makes possible the determination of the moments of inertia of atomic nuclei and molecules, isotopic mass, arrangement and strength of atomic bonds in the molecule and the frequencies of their vibrations. By knowing the frequencies for pure substances, molecular analyses of complicated mixtures of various organic rubbers, accelerators and other substances could be performed. The study of linear absorption spectra is the basis of the spectrographic method in the infrared region. Since the frequencies of near infrared radiation correspond to the characteristic frequencies of the atoms in the molecules, this method could be used to obtain interesting information concerning the structure of organic molecules, the chemical structure of high molecular weight compounds, the determination of the presence of specific groups or atoms in the rubber molecule, the character of the bonds between these groups and the order of arrangement of the individual chain links. This is true because the position of the absorption bands, which are specific for a given group of atoms, is practically the same for the different combinations in which the group occurs. The complicated process of polymerization of diene and vinyl compounds and the structure of different types of rubbers can be investigated with the aid of infrared spectroscopy. For example, Table I lists the characteristic absorption frequencies in the infrared region for some important chemical combinations.

scholarly journals Interbrain Synchrony in the Expectation of Cooperation Behavior: A Hyperscanning Study Using Functional Near-Infrared Spectroscopy

2020 ◽  
Vol 11 ◽  
Author(s):  
Mingming Zhang ◽  
Huibin Jia ◽  
Mengxue Zheng
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Mirror Neuron System ◽  
Cooperative Behavior ◽  
Inferior Frontal Gyrus ◽  
Neural Substrates ◽  
Environmental Cues ◽  
Functional Near Infrared Spectroscopy ◽  
The Individual

Expectation of others’ cooperative behavior plays a core role in economic cooperation. However, the dynamic neural substrates of expectation of cooperation (hereafter EOC) are little understood. To fully understand EOC behavior in more natural social interactions, the present study employed functional near-infrared spectroscopy (fNIRS) hyperscanning to simultaneously measure pairs of participants’ brain activations in a modified prisoner’s dilemma game (PDG). The data analysis revealed the following results. Firstly, under the high incentive condition, team EOC behavior elicited higher interbrain synchrony (IBS) in the right inferior frontal gyrus (rIFG) than individual EOC behavior. Meanwhile, the IBS in the IFG could predict the relationship between empathy/agreeableness and EOC behavior, and this prediction role was modulated by social environmental cues. These results indicate the involvement of the human mirror neuron system (MNS) in the EOC behavior and the different neural substrates between team EOC and individual EOC, which also conform with theory that social behavior was affected by internal (i.e., empathy/agreeableness) and external factors (i.e., incentive). Secondly, female dyads exhibited a higher IBS value of cooperative expectation than male dyads in the team EOC than the individual EOC in the dorsal medial prefrontal cortex (DMPFC), while in the individual EOC stage, the coherence value of female dyads was significantly higher than that of male dyads under the low incentive reward condition in the rIFG. These sex effects thus provide presumptive evidence that females are more sensitive to environmental cues and also suggest that during economic social interaction, females’ EOC behavior depends on more social cognitive abilities. Overall, these results raise intriguing questions for future research on human cooperative behaviors.

scholarly journals Recent advances in cerebral oximetry. Assessment of cerebral autoregulation with near-infrared spectroscopy: myth or reality?

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1615 ◽  
Author(s):  
Anneliese Moerman ◽  
Stefan De Hert
Keyword(s):  
Blood Pressure ◽  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Cerebral Autoregulation ◽  
Near Infrared ◽  
Cerebral Oximetry ◽  
Cerebral Oxygen ◽  
Pressure Management ◽  
Major Step ◽  
The Individual

In recent years, the feasibility of near-infrared spectroscopy to continuously assess cerebral autoregulation has gained increasing interest. By plotting cerebral oxygen saturation over blood pressure, clinicians can generate an index of autoregulation: the cerebral oximetry index (COx). Successful integration of this monitoring ability in daily critical care may allow clinicians to tailor blood pressure management to the individual patient’s need and might prove to be a major step forward in terms of patient outcome.

scholarly journals Guiding functional near-infrared spectroscopy optode-layout design using individual (f)MRI data: Effects on signal quality and sensitivity

2020 ◽  
Author(s):  
A. Benitez-Andonegui ◽  
M. Lührs ◽  
L. Nagels-Coune ◽  
D. Ivanov ◽  
R. Goebel ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Probabilistic Approach ◽  
Layout Design ◽  
Signal Quality ◽  
Measured Signal ◽  
Functional Near Infrared Spectroscopy ◽  
Cortical Regions ◽  
The Individual

AbstractDesigning optode layouts is an essential step for functional near-infrared spectroscopy (fNIRS) experiments as the quality of the measured signal and the sensitivity to cortical regions-of-interest depend on how optodes are arranged on the scalp. This becomes particularly relevant for fNIRS-based brain-computer interfaces (BCIs), where developing robust systems with few optodes is crucial for clinical applications. Available resources often dictate the approach researchers use for optode-layout design. Here we compared four approaches that incrementally incorporated subject-specific magnetic resonance imaging (MRI) information while participants performed mental-calculation, mental-rotation and inner-speech tasks. The literature-based approach (LIT) used a literature review to guide the optode layout design. The probabilistic approach (PROB), employed individual anatomical data and probabilistic maps of functional MRI (fMRI)-activation from an independent dataset. The individual fMRI (iFMRI) approach used individual anatomical and fMRI data, and the fourth approach used individual anatomical, functional and vascular information of the same subject (fVASC). The four approaches resulted in different optode layouts and the more informed approaches outperformed the minimally informed approach (LIT) in terms of signal quality and sensitivity. Further, PROB, iFMRI and fVASC approaches resulted in a similar outcome. We conclude that additional individual MRI data leads to a better outcome, but that not all the modalities tested here are required to achieve a robust setup. Finally, we give preliminary advice to efficiently using resources for developing robust optode layouts for BCI and neurofeedback applications.

The application of near infrared spectroscopy to predict faecal nitrogen and phosphorus in multiple ruminant herbivore species

2020 ◽  
Vol 42 (6) ◽  
pp. 415
Author(s):  
D. R. Tolleson ◽  
J. P. Angerer
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Coefficient Of Determination ◽  
Individual Species ◽  
Nitrogen And Phosphorus ◽  
Faecal Nitrogen ◽  
Herbivore Species ◽  
The Individual ◽  
Leave One Out

Near infrared spectroscopy (NIRS) was applied to determine faecal nitrogen and phosphorus using a temporo-spatially diverse dataset derived from multiple ruminant herbivore species (i.e. cattle, bison, deer, elk, goats, and sheep). Single-species NIRS calibrations have previously been developed to predict faecal constituents. Multi-species NIRS calibrations have previously been developed for herbivore faecal nitrogen but not for faecal phosphorus. Faecal samples representing a herd or flock composite were analysed via NIRS (400–2498nm). Calibration sets for faecal nitrogen and phosphorus were developed from: (1) all samples from all six species, (2) all cattle samples only, (3) all samples except those from bison, (4) all samples except those from deer, (5) all samples except those from elk, (6) all samples except those from goats, and (7) all samples except those from sheep. Validation sample sets included: (1) each of the individual species (predicted with a cattle only-derived calibration), and (2) each of the individual species (other than cattle) predicted with a multi-species calibration constructed from all cattle samples plus those samples from the remaining four species (i.e. ‘leave-one-out’). All multiple coefficient of determination (R2) values for faecal nitrogen calibrations were ≥0.97. Corresponding standard error of cross validation (SECV) values were ≤0.13. Validation simple coefficient of determination (r2) and standard error of prediction (SEP) of each alternate species using the cattle-derived calibration ranged from 0.76 to 0.84, and 0.28 to 0.5 respectively. Similar values for the sequential species leave-one-out validation for faecal nitrogen were 0.67 to 0.89, and 0.17 to 0.47 respectively. All R2 values for faecal phosphorus calibrations were ≥0.79; corresponding SECV were ≤0.14. Validation r2 and SEP of each alternate species using the cattle-derived phosphorus calibration were ≤0.63 and ≥0.13 respectively. Similar values for the sequential species leave-one-out validation were ≤0.66 and ≥0.22 respectively for faecal phosphorus. Multi-species faecal NIRS calibrations can be developed for monitoring applications in which determination of faecal nitrogen is appropriate, e.g. free-ranging herbivore nutrition, nitrogen deposition from animal faeces on rangelands with declining forage quality, or runoff from confined animal feeding operations. Similar calibrations for faecal phosphorus require additional research to ascertain their applicability.

scholarly journals GG Tauri A: dark shadows on the ringworld

2019 ◽  
Vol 628 ◽  
pp. A88 ◽  
Author(s):  
R. Brauer ◽  
E. Pantin ◽  
E. Di Folco ◽  
E. Habart ◽  
A. Dutrey ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Near Infrared ◽  
Binary Star ◽  
Scattered Light ◽  
Circumstellar Disks ◽  
Infrared Emission ◽  
Close Binary ◽  
Spectral Energy ◽  
Multiple Star ◽  
The Individual

Context. With its high complexity, large size, and close distance, the ringworld around GG Tau A is an appealing case to study the formation and evolution of protoplanetary disks around multiple star systems. However, investigations with radiative transfer models usually neglect the influence of the circumstellar dust around the individual stars. Aims. We investigate how circumstellar disks around the stars of GG Tau A influence the emission that is scattered at the circumbinary disk and if constraints on these circumstellar disks can be derived. Methods. We performed radiative transfer simulations with the POLArized RadIation Simulator (POLARIS) to obtain spectral energy distributions and emission maps in the H-Band (near-infrared). Subsequently, we compared them with observations to achieve our aims. Results. We studied the ratio of polarized intensity at different locations in the circumbinary disk. We conclude that the observed scattered-light near-infrared emission is best reproduced if the circumbinary disk lies in the shadow of at least two coplanar circumstellar disks surrounding the central stars. This implies that the inner wall of the circumbinary disk is strongly obscured around the midplane, while the observed emission is actually dominated by the upper-most disk layers. In addition, the inclined dark lane (“gap”) on the western side of the circumbinary disk, which has been a stable, nonrotating, feature for approximately 20 yr, can only be explained by the self-shadowing of a misaligned circumstellar disk surrounding one of the two components of the secondary close-binary star GG Tau Ab.

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