scholarly journals Prisma the Instruments

1993 ◽  
Vol 137 ◽  
pp. 672-674
Author(s):  
Andrew Jones
Keyword(s):  
High Resolution ◽  
Stellar Structure ◽  
Quality Data ◽  
The Sun ◽  
Calibration Point ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Very High ◽  
Selection Of

Our understanding of Solar structure has increased dramatically in the last couple of decades thanks mainly to the opening of new windows of observation providing high quality data to theoreticians with access to powerful computing facilities. Two of the new windows were UV and X-ray images of the Sun, allowing a detailed view of the upper solar atmosphere, and the development of very high resolution spectrometers allowing us to exploit the solar oscillations to probe the internal structure of the Sun. It is the goal of PRISMA to extend these techniques to other stars, which using the Sun as a calibration point will allow us to explore stellar structure and evolution in ways not possible now.In this poster I will present a possible selection of instruments able to achieve this goal, and explain some of the rationale in their design. A more general overview is presented by T. Appouchaux also in these proceedings. It must be stressed that these are not the definitive instruments to be flown on PRISMA, but rather result from a study to show the feasibility of such a mission. Should PRISMA be chosen as the next ESA medium sized mission, an ‘Announcement of Opportunity’ wiH be issued by ESA and the responses of all people interested in constructing the instrument will be considered.

scholarly journals The Sun at high resolution: first results from the Sunrise mission

2010 ◽  
Vol 6 (S273) ◽  
pp. 226-232 ◽  
Author(s):  
S. K. Solanki ◽  
P. Barthol ◽  
S. Danilovic ◽  
A. Feller ◽  
A. Gandorfer ◽  
...  
Keyword(s):  
High Resolution ◽  
Solar Observatory ◽  
Quality Data ◽  
The Sun ◽  
Stabilization System ◽  
High Quality ◽  
High Quality Data ◽  
Image Stabilization ◽  
Solar Convection ◽  
First Results

AbstractThe Sunrise balloon-borne solar observatory consists of a 1m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system and further infrastructure. The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and magnetic fields at a resolution of around 100 km in the quiet Sun. Here we describe very briefly the mission and the first results obtained from the Sunrise data, which include a number of discoveries.

scholarly journals R factors in Rietveld analysis: How good is good enough?

2006 ◽  
Vol 21 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Brian H. Toby
Keyword(s):  
Rietveld Analysis ◽  
Poor Quality ◽  
Quality Data ◽  
High Quality ◽  
High Quality Data ◽  
Poor Quality Data ◽  
Error Index ◽  
R Factors ◽  
Very High

The definitions for important Rietveld error indices are defined and discussed. It is shown that while smaller error index values indicate a better fit of a model to the data, wrong models with poor quality data may exhibit smaller values error index values than some superb models with very high quality data.

Selection of a Set of High-Quality Data for B Cell Antigen Analysis

1984 ◽  
pp. 69-71
Author(s):  
W. H. Marshall ◽  
G. Sierp ◽  
T. Barbalho ◽  
F. T. Christiansen ◽  
S. Scholz ◽  
...  
Keyword(s):  
B Cell ◽  
Quality Data ◽  
High Quality ◽  
High Quality Data ◽  
Cell Antigen ◽  
Selection Of

scholarly journals X-ray Variability of the Flare Star CC Eri

1995 ◽  
Vol 151 ◽  
pp. 170-170
Author(s):  
H.C. Pan ◽  
C. Jordan
Keyword(s):  
Binary Star ◽  
Emission Measure ◽  
Quality Data ◽  
Spectral Variability ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Spectroscopic Binary ◽  
Two Temperature ◽  
Continuous Temperature

The flare/spotted spectroscopic binary star CC Eri (HD 16157) was observed in the periods 1990 July 9-11 and 1992 January 26-27 with the ROSAT PSPC detector (Pan and Jordan 1995). These high quality data give the first information on the temporal and spectral variability of CC Eri in the X-ray energy band.During the ROSAT observations the X-ray intensity of the source is variable on timescales from a few minutes to several hours. The X-ray luminosity is in the range 2.5 – 6.8 × 1029 erg s−1, which is similar to values found from previous measurements with the Einstein IPC and EXOSAT LE. On 1990 July 10 an X-ray flare-like event was detected with an exponential rise time of about one hour and a decay time of about two hours. The X-ray spectrum of CC Eri can be described by current thermal plasma codes with two temperature components or with a continuous temperature distribution. The spectral results show that plasma at Te ∼ 107 K exists in the corona of CC Eri. We find that the X-ray spectrum is also variable and the variations of the emission measure, and to a lesser extent of the temperature, are correlated with the source intensity.

scholarly journals Oscillations in the Sun with SONG: Setting the scale for asteroseismic investigations

2019 ◽  
Vol 623 ◽  
pp. L9 ◽  
Author(s):  
M. Fredslund Andersen ◽  
P. Pallé ◽  
J. Jessen-Hansen ◽  
K. Wang ◽  
F. Grundahl ◽  
...  
Keyword(s):  
Power Spectrum ◽  
Quality Data ◽  
Scaling Relations ◽  
The Sun ◽  
Average Amplitude ◽  
Echelle Spectrograph ◽  
High Quality ◽  
Data Set ◽  
High Quality Data ◽  
High Cadence

Context. We present the first high-cadence multiwavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar échelle spectrograph at the Hertzsprung SONG Telescope operating at the Teide Observatory. Aims. Our aim was to produce a high-quality data set and reference values for the global helioseismic parameters νmax, ⊙ and Δν⊙ of the solar p-modes using the SONG instrument. The obtained data set or the inferred values should then be used when the scaling relations are applied to other stars showing solar-like oscillations observed with SONG or similar instruments. Methods. We used different approaches to analyse the power spectrum of the time series to determine νmax, ⊙: simple Gaussian fitting and heavy smoothing of the power spectrum. We determined Δν⊙ using the method of autocorrelation of the power spectrum. The amplitude per radial mode was determined using the method described in Kjeldsen et al. (2008, ApJ, 682, 1370). Results. We found the following values for the solar oscillations using the SONG spectrograph: νmax, ⊙ = 3141 ± 12 μHz, Δν⊙ = 134.98 ± 0.04 μHz, and an average amplitude of the strongest radial modes of 16.6 ± 0.4 cm s−1. These values are consistent with previous measurements with other techniques.

scholarly journals Monitoring the TROPOMI-SWIR module instrument stability using desert sites

2021 ◽  
Author(s):  
Tim A. van Kempen ◽  
Filippo Oggionni ◽  
Richard M. van Hees
Keyword(s):  
Quality Data ◽  
Light Sources ◽  
High Quality ◽  
High Quality Data ◽  
Signal Stability ◽  
Independent Validation ◽  
Internal Calibration ◽  
Global Coverage ◽  
Operational Data ◽  
Very High

Abstract. Since its launch in 2017, the TROPOMI instrument on S-5P has provided very high quality data using daily global coverage for a number of key atmospheric trace gasses. Over its first 1,000 days in operations, the SWIR module has been very stable and the continuously monitored calibration has remained of high quality. This calibration relies on a combination of extensive pre-launch and post-launch measurements, complemented by regular monitoring of internal light sources and background measurements. In this paper we present a method and results for independent validation of the SWIR module calibration and instrument stability by examining the signal stability of a sample of 23 pseudo-invariant calibration desert sites. The data covers over two years of operational data. With a Lambertian surface assumption, the results show that the SWIR module has little to no instrument degradation down to an accuracy of about 0.3 % per year, validating results obtained from the internal calibration suite. The method presented here will be used as ongoing validation of the SWIR calibration.

scholarly journals Intact NMR spectroscopy: slow high-resolution magic angle spinning chemical shift imaging

The Analyst ◽  
2020 ◽  
Vol 145 (7) ◽  
pp. 2520-2524 ◽  
Author(s):  
Covadonga Lucas-Torres ◽  
Alan Wong
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Chemical Shift ◽  
Chemical Shift Imaging ◽  
Magic Angle Spinning ◽  
Quality Data ◽  
Magic Angle ◽  
High Quality ◽  
High Quality Data ◽  
Angle Spinning

A slow sample spinning strategy was implemented and evaluated as a highly informative NMR profiling approach for intact specimens, with high quality data and feasibility.

scholarly journals Accurate Prediction of Hydration Sites of Proteins Using Energy Model With Atom Embedding

2021 ◽  
Vol 8 ◽  
Author(s):  
Pin Huang ◽  
Haoming Xing ◽  
Xun Zou ◽  
Qi Han ◽  
Ke Liu ◽  
...  
Keyword(s):  
Protein Structures ◽  
Score Function ◽  
Quality Data ◽  
Model Quality ◽  
High Quality ◽  
High Quality Data ◽  
Arbitrary Position ◽  
Placement Algorithm ◽  
Protein Dataset ◽  
Selection Of

We propose a method based on neural networks to accurately predict hydration sites in proteins. In our approach, high-quality data of protein structures are used to parametrize our neural network model, which is a differentiable score function that can evaluate an arbitrary position in 3D structures on proteins and predict the nearest water molecule that is not present. The score function is further integrated into our water placement algorithm to generate explicit hydration sites. In experiments on the OppA protein dataset used in previous studies and our selection of protein structures, our method achieves the highest model quality in terms of F1 score, compared to several previous studies.

A fibre-based crystal mounting technique for protein cryocrystallography

2012 ◽  
Vol 45 (2) ◽  
pp. 362-366 ◽  
Author(s):  
Michihiro Sugahara
Keyword(s):  
Data Collection ◽  
Success Rate ◽  
Single Crystals ◽  
Conventional Technique ◽  
Synthetic Zeolite ◽  
Quality Data ◽  
High Quality ◽  
High Quality Data ◽  
X Ray ◽  
Loop Technique

The CryoFibre, a crystal mounting tool, has been developed for protein cryocrystallography. The technique attaches single crystals to the tips of polyester fibres, allowing removal of excess liquid around each crystal. Single-wavelength anomalous dispersion phasing using a Cu Kα X-ray source (Cu SAD) was applied to crystals from five proteins without any derivatization, demonstrating a clear improvement in the success rate of Cu SAD compared with the conventional loop technique. In addition, a xylanase crystal on the surface of a synthetic zeolite as a hetero-epitaxic nucleant was directly mounted on the CryoFibre without separation treatment of the crystal from the zeolite. The crystal had a lower mosaicity than that observed using the conventional technique, indicating that the fibre technique is suitable for high-quality data collection from zeolite-mediated crystals.

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