Spectroscopy of a Solar Prominence with the Narrow-Bandpass Filter

1994 ◽  
Vol 144 ◽  
pp. 343-344
Author(s):  
P. Rudawy
Keyword(s):  
Optical Thickness ◽  
Large Scale ◽  
Bandpass Filter ◽  
Solar Limb ◽  
Physical Parameters ◽  
Two Dimensional ◽  
Line Profiles ◽  
Solar Prominence ◽  
Quiescent Prominence ◽  
Made In

AbstractObservations and analysis of a quiescent prominence above the solar limb are presented. The set of quasi-monochromatic images of the prominence made in a few wavelengths of Hα, Hβand D3lines have been used for reconstruction of the coarse line profiles. Two-dimensional maps of the main physical parameters of the prominence matter-macroscopic and turbulent velocities, electron temperature, density and optical thickness have been constructed. Presented method of low-resolution spectroscopy is useful for investigations of the variety of large-scale solar phenomena.

Electron Densities in Solar Prominences

1994 ◽  
Vol 144 ◽  
pp. 381-383
Author(s):  
J. E. Wiik ◽  
P. Heinzel ◽  
B. Schmieder
Keyword(s):  
Optical Thickness ◽  
Field Of View ◽  
Line Of Sight ◽  
Two Dimensional ◽  
Line Profiles ◽  
Quiescent Prominence ◽  
Electron Densities ◽  
Solar Prominences ◽  
Thickness Variations ◽  
Limiting Values

AbstractObservations of a quiescent prominence made with the MSDP spectrograph at the Pic du Midi Observatory provided Hαline profiles in each pixel of a 2D field of view. Comparing the absolute observed intensities with values derived from NLTE computations, we estimated the range ofelectron densitiesNe≈ 1 – 5 × 1010cm−3,source functionsS/Ic≈ 0.07 – 0.12, andoptical thicknessτ ≈ 0.3 – 8.0 within the observed prominence. Two dimensional maps of the electron densities are presented assuming two limiting values of the geometrical thickness along the line-of-sight. It is shown that if we consider geometrical thickness variations within a factor of about four, the electron density will be determined to within a factor of two, just by measuring the Hαline intensity.

scholarly journals Small-scale turbulence characteristics of two-dimensional bluff body wakes

2002 ◽  
Vol 459 ◽  
pp. 67-92 ◽  
Author(s):  
R. A. ANTONIA ◽  
T. ZHOU ◽  
G. P. ROMANO
Keyword(s):  
Porous Body ◽  
Large Scale ◽  
Bluff Body ◽  
Inertial Range ◽  
Small Scale ◽  
Bluff Bodies ◽  
Two Dimensional ◽  
The Difference ◽  
Scale Turbulence ◽  
Made In

Measurements have been made in nominally two-dimensional turbulent wakes generated by five different bluff bodies. Each wake has a different level of large-scale organization which is reflected in different amounts of large-scale anisotropy. Structure functions of streamwise (u) and lateral (v) velocity fluctuations at approximately the same value of Rλ, the Taylor microscale Reynolds number, indicate that inertial-range scales are significantly affected by the large-scale anisotropy. The effect is greater on v than u and more pronounced for the porous-body wakes than the solid-body wakes. In particular, ‘relative’ values of the scaling (or power-law) exponents indicate that the magnitude of the transverse exponents can exceed that of the longitudinal ones in the porous-body wakes. This is supported by the inertial-range behaviour of the spectra of u and v. The difference between the transverse and longitudinal exponents appears to depend on the large-scale anisotropy of the flow, as measured by the ratio of the variances of v and u and ratio of the integral length scales of v and u. The spanwise vorticity spectra are much less affected by the anisotropy than the spectra of u and v.

scholarly journals Prominence Emission Lines Observed With SUMER and Two Ground-based Telescopes

1998 ◽  
Vol 167 ◽  
pp. 196-200
Author(s):  
C.R. de Boer ◽  
G. Stellmacher ◽  
E. Wiehr
Keyword(s):  
Optical Thickness ◽  
Emission Lines ◽  
Two Dimensional ◽  
Quiescent Prominence ◽  
Euv Emission ◽  
Ionization Temperature ◽  
Balmer Lines ◽  
Higher Temperature ◽  
Line Widths ◽  
Emission Ratios

AbstractTwo sets of H, He, and Ca+ emission lines were observed in a quiescent prominence simultaneously with the VTT and the Gregory telescope on Tenerife. At the same time, SUMER took two scans of low-ionized EUV emission lines.The emission ratios of Ca+–to–Balmer lines from ground vary little in the prominence, indicating a largely constant gas-pressure. In contrast, the ratio of He–to–Balmer from the ground shows the (known) increase toward the prominence borders, indicating higher temperature there. Similarly, the two-dimensional distributions of the ratios S IV/N II and C III/He I show pronounced bright prominence rims.The reduced He 537Å and He 584Å line widths are 2.6 and 3.6 times larger, respectively, than those of He D3 and He 3888Å. Explaining this by the optical thickness yields τ0 = 104 and τ0 = 2 · 105 for the two EUV lines. The total He 584 emission amounts to 13 watt/m2 ster in the main prominence body where the D3 line yields 4 watt/m2 ster; existing models, however, predict a factor 0.18.The widths of simultaneously observed optical lines with different atomic weights yield thermal and non-thermal broadening parameters of Tkin ≈ 8000 K and 2.5 < ξ < 6.5 km/s. The EUV lines, however, show line widths which correspond to much higher temperatures and non-thermal velocities. Assuming for each ion the corresponding ionization temperature, the line widths require non-thermal velocities of 15–40 km/s which is similar to values for the quiet corona.

Spectrophotometric measurements of objective-prism spectra

1966 ◽  
Vol 24 ◽  
pp. 118-119
Author(s):  
Th. Schmidt-Kaler
Keyword(s):  
Progress Report ◽  
Two Dimensional ◽  
Objective Prism ◽  
Made In

I should like to give you a very condensed progress report on some spectrophotometric measurements of objective-prism spectra made in collaboration with H. Leicher at Bonn. The procedure used is almost completely automatic. The measurements are made with the help of a semi-automatic fully digitized registering microphotometer constructed by Hög-Hamburg. The reductions are carried out with the aid of a number of interconnected programmes written for the computer IBM 7090, beginning with the output of the photometer in the form of punched cards and ending with the printing-out of the final two-dimensional classifications.

scholarly journals Comparison of Some Physical Parameters of Whole and Scored Lisinopril and Lisinopril/Hydrochlorthiazide Tablets

2008 ◽  
Vol 8 (4) ◽  
pp. 391-395 ◽  
Author(s):  
Edina Vranić ◽  
Alija Uzunović
Keyword(s):  
Large Scale ◽  
Testing Procedure ◽  
Physical Parameters ◽  
Hardness Testing ◽  
Disintegration Time ◽  
Adequate Dose ◽  
Response Information ◽  
Tablet Splitting ◽  
Good Patient Compliance ◽  
Accepted Practice

Tablets are one of the most popular and preferred solid dosage forms because they can be accurately dosed, easily manufactured and packaged on a large scale, have good physical and chemical stability, and can contribute to good patient compliance given their ease of administration. The ability to match doses to patients depends on the availability of multiple dose sizes and adequate dose-response information. These are not always provided, so splitting of the tablets is sometimes necessary, Tablet splitting is an accepted practice in dispensing medication, It has been used when a dosage form of the required strength is not available commercially. The aim of our study was to compare some physical parameters of whole and scored lisinopril and lisinopril/hydrochlorthiazide tablets and to accept or exclude their influence on the obtaining of required dosage.According to the results obtained, we may conclude that tablets from batch “I” “IL “III” and “IV” satisfied pharmacopeial requirements concerning crushing strength, friability, disintegration time and mass uniformity. The hardness testing showed acceptable reproducibility and indicate that the data variation was primarily from the irreversible changes in the structure of tablet samples. The act of compacting powders stores energy within the tablets, by shifting or compressing the intermolecular bonds within the particles. The tablets have a natural tendency to relax once pressure is removed, and this tendency works against the interparticle bonding formed during compression. Hardness testing procedure causes irreversible changes in this structure.

Wrist strength limitations to manual exertion capability

1998 ◽  
Vol 1 (2) ◽  
pp. 107-121
Author(s):  
Khaled W. Al-Eisawi ◽  
Carter J. Kerk ◽  
Jerome J. Congleton
Keyword(s):  
Biomechanical Modeling ◽  
Two Dimensional ◽  
Wrist Flexion ◽  
College Age ◽  
Biomechanical Models ◽  
Radial Deviation ◽  
Flexion Strength ◽  
Made In

This study evaluated wrist strength limitations to manual exertion capability in two-dimensional static biomechanical modeling. The researchers hypothesized that wrist strength does not limit manual exertion capability - an assumption commonly made in many strength biomechanical models. An experiment was conducted on 15 right-handed males of college age. Isometric wrist flexion strength was measured at two elbow angles: 90 degree and 135 degree and in two wrist positions: neutral and 45 degree extended. Isometric wrist radial deviation strength was measured at the same two elbow angles and in two wrist positions: neutral and 30 degree ulnarly deviated. Minimum wrist strength limits for which wrist strength does not limit maximal moments about the elbow in manual hand exertions were calculated and compared to their corresponding measured wrist strength moments using paired t-tests. In general, wrist strength was non-limiting. However, wrist flexion strength in the 45 degree extended wrist posture was limiting. Weak-wrist subjects showed more wrist strength limitations than strong-wrist subjects.

Solution‐Processed Large‐Scale Concentric‐Ring Laser on Two‐Dimensional Ruddlesden–Popper Perovskites Thin Films

2021 ◽  
pp. 2100193
Author(s):  
Peng Liu ◽  
Bingqian Zhang ◽  
Qing Liao ◽  
Guifen Tian ◽  
Chunling Gu ◽  
...  
Keyword(s):  
Thin Films ◽  
Ring Laser ◽  
Large Scale ◽  
Two Dimensional ◽  
Concentric Ring ◽  
Solution Processed
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