scholarly journals A Novel Approach for the Determination of the Height of the Tropopause from Ground-Based GNSS Observations

2020 ◽  
Vol 12 (2) ◽  
pp. 293 ◽  
Author(s):  
Jorge Mendez Astudillo ◽  
Lawrence Lau ◽  
Yu-Ting Tang ◽  
Terry Moore
Keyword(s):  
Refractive Index ◽  
Lapse Rate ◽  
Radiosonde Data ◽  
Precision Data ◽  
Novel Approach ◽  
Radio Signals ◽  
High Precision Data ◽  
Novel Method ◽  
Gnss Data

In this paper, we present a new method to calculate the height of the second lapse-rate tropopause (LRT2) using GNSS high-precision data. The use of GNSS data for monitoring the atmosphere is possible because as the radio signals propagate through the troposphere, they are delayed according to the refractive index of the path of the signal. We show that by integrating the vertical profile of the refractive index in the troposphere, we are able to determine the altitude of LTR2. Furthermore, as GNSS data is available from many stations around all latitudes of the globe and make up a network with high spatial and temporal resolution, we can monitor the diurnal cycle of the variables related to the refractive index of the path of the signal. A comparison between the heights of the LRT2 obtained with radiosonde data and with this novel method is presented in the paper, and it shows good agreement. The average difference found is ≤1 km for stations between the latitudes of 30°S and 30°N.

scholarly journals Updated astrometry and masses of the LUH 16 brown dwarf binary

2018 ◽  
Vol 618 ◽  
pp. A111 ◽  
Author(s):  
P. F. Lazorenko ◽  
J. Sahlmann
Keyword(s):  
High Precision ◽  
Photographic Plate ◽  
Brown Dwarf ◽  
Precision Data ◽  
Orbital Parameters ◽  
Very Large Telescope ◽  
High Precision Data ◽  
The Absolute ◽  
The Individual

The nearest known binary brown dwarf WISE J104915.57–531906.1AB (LUH 16) is a well-studied benchmark for our understanding of substellar objects. Previously published astrometry of LUH 16 obtained with FORS2 on the Very Large Telescope was affected by errors that limited its use in combination with other datasets, thereby hampering the determination of its accurate orbital parameters and masses. We improve upon the calibration and analysis of the FORS2 astrometry with the help of Gaia DR2 to generate a high-precision dataset that can be combined with present and future LUH 16 astrometry. We demonstrate its use by combining it with available measurements from the Hubble Space Telescope (HST) and Gemini/GeMS and deriving updated orbital and mass parameters. Using Gaia DR2 as astrometric reference field, we derived the absolute proper motion and updated the absolute parallax of the binary to 501.557 ± 0.082 mas. We refined the individual dynamical masses of LUH 16 to 33.5 ± 0.3 M Jup (component A) and 28.6 ± 0.3 M Jup (component B), which corresponds to a relative precision of ∼1% and is three to four times more precise than previous estimates. We found that these masses show a weak dependence on one datapoint extracted from a photographic plate from 1984. The exact determination of a residual mass bias, if any, will be possible when more high-precision data can be incorporated in the analysis.

scholarly journals Fundamental parameters of B type stars

2014 ◽  
Vol 9 (S307) ◽  
pp. 129-130
Author(s):  
María-Fernanda Nieva
Keyword(s):  
Mass Range ◽  
Eclipsing Binaries ◽  
Precision Data ◽  
Hydrogen Burning ◽  
Fundamental Parameters ◽  
Accuracy And Precision ◽  
High Precision Data ◽  
Ob Associations ◽  
Better Than

AbstractFundamental parameters of 26 well-studied sharp-lined single early B-type stars in OB associations and in the field within a distance of ≤400 pc from the Sun are compared to high-precision data from detached eclipsing binaries (DEBs). Fundamental parameters are derived from accurate and precise atmospheric parameters determined earlier by us from non-LTE analyses of high-quality spectra, utilising the new Geneva stellar evolution models in the mass-range ~6 to 18 M⊙ at metallicity Z = 0.014. Evolutionary masses, radii and luminosities are determined to better than typically 5%, 10%, and 20% uncertainty, respectively, facilitating the mass-radius and mass-luminosity relationships to be recovered for single core hydrogen-burning objects with a similar precision as derived from DEBs. Good agreement between evolutionary and spectroscopic masses is found. Absolute visual and bolometric magnitudes are derived to typically ~0.15-0.20 mag uncertainty. Metallicities are constrained to better than 15-20% uncertainty and tight constraints on evolutionary ages of the stars are provided. The spectroscopic distances and ages of individual sample stars agree with independently derived values for the host OB associations. The accuracy and precision achieved in the determination of fundamental stellar parameters from the quantitative spectroscopy of single early B-type stars comes close (within a factor 2-4) to data derived from DEBs.

A Simple Method for Determination of the Elastic Modulus of Thin Films on a Substrate

1993 ◽  
Vol 308 ◽  
Author(s):  
M.V. Swain ◽  
E.R. Weppelmann
Keyword(s):  
Thin Films ◽  
High Precision ◽  
Elastic Contact ◽  
Precision Data ◽  
Simple Method ◽  
Tin Film ◽  
High Precision Data ◽  
Properties Of Materials ◽  
Force Displacement

ABSTRACTHigh precision force displacement indenting instruments are now widely used for the determination of the mechanical properties of materials. However, for thin films attached to a substrate, the basis of any analysis of such high precision data is still limited. In this study the force displacement data has been generated using spherically tipped indenters of radii from 5 to 150 μm loaded onto a 2.74 μm thick TiN film on a silicon substrate as well as onto the substrate directly. Data have been generated using two loading procedures, continuous and load partial-unloading, almost entirely within the elastic contact regime. The results are analysed to determine the modulus of the TiN film.

scholarly journals The nearby triple star HIP 101955

2017 ◽  
Vol 12 (S330) ◽  
pp. 356-357
Author(s):  
Fang Xia
Keyword(s):  
Kinematic Parameters ◽  
Precision Data ◽  
Body Model ◽  
Dynamical State ◽  
High Precision Data ◽  
Three Body ◽  
Astrometric Data ◽  
Triple Star

AbstractThe nearby triple star HIP 101955 with strongly inclined orbit still remains. Thus the long-term dynamical stability deserves to be discussed based on the new dynamical state parameters (component masses and kinematic parameters) derived from fitting the accurate three-body model to the radial velocity, the Hipparcos Intermediate Astrometric Data (HIAD), and the accumulated speckle and visual data. It is found that the three-body system remains integrated and most likely undergoes Kozai cycles. With the already accumulated high-precision data, the three-body effects cannot always be neglected in the determination of the dynamical state. And it is expected that this will be the general case under the available Gaia data.

scholarly journals Fast Cross-Linking-Characterization of Waveguide-Polymers on Wafers by Imaging Low-Coherence Interferometry

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1046
Author(s):  
Christopher Taudt ◽  
Bryan Nelsen ◽  
Sandra Schlögl ◽  
Edmund Koch ◽  
Peter Hartmann
Keyword(s):  
Refractive Index ◽  
Cross Linking ◽  
Imaging Spectrometer ◽  
Low Coherence ◽  
Spatially Resolved ◽  
Low Coherence Interferometry ◽  
Novel Method ◽  
Phase Data

This work introduces a novel method to characterize cross-linking differences in spincast polymers for waveguide applications. The method is based on a low-coherence interferometer which utilizes an imaging spectrometer to gather spatially resolved data along a line without the need for scanning. The cross-linking characterization is performed by the determination of the wavelength-dependent optical thickness. In order to do this, an algorithm to analyze the wrapped phase data and extract refractive index information is developed. Finally, the approach is tested on photo-lithographically produced samples with lateral refractive index differences in pitches of 50 μm.

scholarly journals Inelastic neutron scattering: a novel approach towards determination of equilibrium isotopic fractionation factors. Size effects on heat capacity and beta-factor of diamond

2020 ◽  
Vol 22 (23) ◽  
pp. 13261-13270
Author(s):  
Andrey A. Shiryaev ◽  
Veniamin B. Polyakov ◽  
Stephane Rols ◽  
Antonio Rivera ◽  
Olga Shenderova
Keyword(s):  
Neutron Scattering ◽  
Size Effects ◽  
Inelastic Neutron Scattering ◽  
Isotopic Fractionation ◽  
Inelastic Neutron ◽  
Novel Approach ◽  
Novel Method ◽  
Bulk Diamond ◽  
Fractionation Factors

Inelastic neutron scattering is a novel method for determination of thermodynamic and isotopic properties of nanoparticles. Influence of surface can be evaluated. The Cv of nanodiamonds is higher and the β-factor is lower than those of bulk diamond.

scholarly journals QCD Analysis of Leading-Neutron Production at HERA: Determination of Neutron Fracture Functions

2018 ◽  
Vol 47 ◽  
pp. 1860094
Author(s):  
Samira Shoeibi ◽  
F. Taghavi-Shahri ◽  
Kurosh Javidan
Keyword(s):  
Large Fraction ◽  
Neutron Production ◽  
Production Data ◽  
Precision Data ◽  
Wide Range ◽  
High Precision Data ◽  
Leading Neutron ◽  
Qcd Analysis ◽  
Hessian Method

The last two decades have seen a growing trend towards the experimental efforts at the electron-proton collider HERA in which have collected high precision data on the spectrum of leading neutron (LN) and leading-proton (LP) carrying a large fraction of the proton’s energy. In our recent study [Phys. Rev. D 95 (2017), 074011], we have proposed an approach based on the Fractures Functions (FF) formalism and have extracted the neutron Fracture Functions (neutron FFs) from a global QCD analysis of LN production data measured by H1 and ZEUS collaborations at HERA. We have shown that considering the approach based on the framework of Fracture Functions, one could phenomenologically parametrize the neutron FFs at the input scale. In order to access the uncertainties for the obtained neutron FFs as well as the LN structure functions and cross section, associated with the uncertainties in the data, we have made an extensive use of the “Hessian method”. Our theory predictions based on the obtained neutron FFs are in satisfactory agreement with all LN data analyzed, for a wide range of [Formula: see text] and [Formula: see text].

The coexistence curve of GeH4 and correction-to-scaling

1983 ◽  
Vol 61 (9) ◽  
pp. 1301-1304 ◽  
Author(s):  
D. Balzarini ◽  
O. G. Mouritsen ◽  
P. Palffy-Muhoray
Keyword(s):  
Refractive Index ◽  
Renormalization Group ◽  
High Precision ◽  
Focal Plane ◽  
Coexistence Curve ◽  
Theoretical Expression ◽  
Precision Data ◽  
High Precision Data ◽  
Correction To Scaling ◽  
Reduced Temperature

High-precision data for the coexistence curve of GeH4 covering the reduced temperature range 10−6 < t < 5 × 10−2 have been derived from measurements of the refractive index by focal plane interference methods. The data are analyzed in terms of correction-to-scaling confluent singularities, [Formula: see text], to yield the nonuniversal amplitudes. This is done by fitting the proposed theoretical expression to the data and by fixing the exponents to their renormalization group values. The data support the theoretical expression for [Formula: see text].

scholarly journals High-Precision AMS 14C Results on TIRI/FIRI Turbidite

Radiocarbon ◽  
2003 ◽  
Vol 45 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Thomas P Guilderson ◽  
John R Southon ◽  
Thomas A Brown
Keyword(s):  
Standard Deviation ◽  
High Precision ◽  
Weighted Average ◽  
Precision Data ◽  
Average Fraction ◽  
High Precision Data ◽  
Fractional Error ◽  
Counting Statistics

Unleached aliquots of TIRI/FIRI turbidite were analyzed by accelerator mass spectronomy (AMS) over a timespan of 18 months. Individual analyses ranged from 18,090–18,245 yr BP with reported errors between 30–50 yr. The weighted average fraction modern (FM) of these 28 measurements is 0.10378 ± 0.00008 (which equates to 18,199 ± 8 yr BP) and the measurements show a 1 standard deviation scatter of 0.00044 (±35 yr). The fractional error of these results indicates reproducibility of individual measurements at the 4 (1σ) level, which is consistent with the quoted counting-statistics-based errors. Laboratories engaged in the determination of 14C results at reasonably high precision should consider taking advantage of the TIRI and FIRI sample materials in the role of process standards. Additional suites of high-precision data are necessary to refine the accuracy of these sample materials.

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