The Absolute Spectrophotometry of 170 Planetary Nebulae

1968 ◽  
pp. 57-58 ◽  
Author(s):  
B. A. Vorontsov-Velyaminov ◽  
E. B. Kostjakova ◽  
O. D. Dokuchaeva ◽  
V. P. Arhipova
Keyword(s):  
Planetary Nebulae ◽  
The Absolute

scholarly journals VLBA H2O and SiO maser observations in the pPN OH 231.8+4.2

2007 ◽  
Vol 3 (S242) ◽  
pp. 338-339
Author(s):  
J.-F. Desmurs ◽  
C. Sánchez Contreras ◽  
V. Bujarrabal ◽  
J. Alcolea ◽  
F. Colomer
Keyword(s):  
High Resolution ◽  
Water Vapour ◽  
Planetary Nebulae ◽  
Absolute Position ◽  
Long Baseline ◽  
The Absolute ◽  
Very Long Baseline Array

AbstractWe report high-resolution observations of H2O, 61,6−52,3 and 28SiO v=2, J=1-0 maser emissions obtained with the Very Long Baseline Array in the bipolar pre-planetary nebulae OH 231.8+4.2 (see Desmurs et al., 2007). A phase referencing technique was used to recover the absolute position of both emissions. We detected two groups of water vapour emission oriented nearly north-south. SiO masers are tentatively found to be placed between the two H2O maser emitting regions.

scholarly journals The Absolute Spectrophotometry of 170 Planetary Nebulae

1968 ◽  
Vol 34 ◽  
pp. 55-58 ◽  
Author(s):  
B.A. Vorontsov-Velyaminov ◽  
E.B. Kostjakova ◽  
O.D. Dokuchaeva ◽  
V.P. Arhipova
Keyword(s):  
Emission Line ◽  
Planetary Nebulae ◽  
Homogeneous System ◽  
Astronomical Institute ◽  
Line Intensities ◽  
Objective Prism ◽  
The Absolute

An investigation of planetary nebulae has been underway at the Sternberg State Astronomical Institute in Moscow for several years. It was begun with the measurement of the emission-line intensities of planetary nebulae in an homogeneous system in absolute units. More than 300 long-exposure objective prism spectrograms were obtained with the 50-cm Maksutov telescope at the Crimean Station of the Institute and with the 70-cm meniscus telescope of the Abastumani Observatory. The dispersion of the spectrograms was 190 and 160 Å/mm at Hγ respectively.

scholarly journals A New Method for Observational Testing of the Planetary Nebulae Nuclei Evolution

1989 ◽  
Vol 131 ◽  
pp. 539-539
Author(s):  
R. Szczerba
Keyword(s):  
Stellar Evolution ◽  
Planetary Nebulae ◽  
Central Star ◽  
The Other ◽  
New Method ◽  
Evolutionary Status ◽  
Applied Method ◽  
Other Hand ◽  
Visual Magnitude ◽  
The Absolute

Planetary nebulae (PNe) are very useful as a tool for testing the theory of stellar evolution. The most widely applied method in this respect is the Hertzsprung-Russell (H-R) diagram. However, the observed positions of planetary nebulae nuclei (PNNi) on the H-R diagram are subject to large uncertainties, mostly due to inaccurate distances to them. On the other hand, the (absolute visual magnitude, age)-diagram also is not free of this problem. Therefore, an attempt has been done to develop a new method which is distance-independent. For comparison between theory and observations we propose the I (Hell λ 4686) /I(H β) versus log [I(H β, PN)/IC (H β, PNN)] diagram. Both ratios reflect the evolutionary status of the central star and the surrounding nebula. Consequently, such diagram is a valuable tool for studying common evolution of the PNN-PN system.

scholarly journals Molecular Hydrogen Microstructures in Planetary Nebulae

Galaxies ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 30
Author(s):  
Stavros Akras ◽  
Denise R. Gonçalves ◽  
Gerardo Ramos-Larios ◽  
Isabel Aleman
Keyword(s):  
Molecular Hydrogen ◽  
Planetary Nebulae ◽  
Central Star ◽  
Morphological Type ◽  
Evolutionary Stage ◽  
The Absolute

Molecular hydrogen (H 2 ) emission is commonly detected in planetary nebulae (PNe), specially in objects with bipolar morphologies. New studies showed that H 2 gas is also packed in microstructures embedded in PNe of any morphological type. Despite the presence of H 2 in cometary knots being known for years, only in the last five years, much deeper imagery of PNe have revealed that H 2 also exists in other types of low-ionisation microstructures (LISs). Significant differences are found between the host PNe of cometary knots and other types of LISs, such as nebula age, central star temperature (evolutionary stage) and the absolute sizes of the microstructure itself.

Bulk standards for low-temperature biological x-ray microanalysis

1984 ◽  
Vol 42 ◽  
pp. 282-283
Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  
Keyword(s):  
Phase Separation ◽  
Low Temperature ◽  
Analytical Method ◽  
Salt Solutions ◽  
Absolute Concentration ◽  
Cooling Process ◽  
X Ray ◽  
The Absolute ◽  
Analytical Procedures ◽  
Electrical Conductors

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.

A Quantitative Ultrastructural Study of Peripheral Blood Lymphocytes Containing Parallel Tubular Arrays in Epstein-Barr Virus and Cytomegalo-Virus Mononucleosis

1981 ◽  
Vol 39 ◽  
pp. 454-455
Author(s):  
C. M. Payne ◽  
P. M. Tennican
Keyword(s):  
Peripheral Blood ◽  
Lymphocyte Count ◽  
Epstein Barr Virus ◽  
Absolute Lymphocyte Count ◽  
Peripheral Blood Lymphocytes ◽  
Clinical State ◽  
Barr Virus ◽  
The Absolute ◽  
Epstein Barr ◽  
Tubular Arrays

In the normal peripheral circulation there exists a sub-population of lymphocytes which is ultrastructurally distinct. This lymphocyte is identified under the electron microscope by the presence of cytoplasmic microtubular-like inclusions called parallel tubular arrays (PTA) (Figure 1), and contains Fc-receptors for cytophilic antibody. In this study, lymphocytes containing PTA (PTA-lymphocytes) were quantitated from serial peripheral blood specimens obtained from two patients with Epstein -Barr Virus mononucleosis and two patients with cytomegalovirus mononucleosis. This data was then correlated with the clinical state of the patient.It was determined that both the percentage and absolute number of PTA- lymphocytes was highest during the acute phase of the illness. In follow-up specimens, three of the four patients' absolute lymphocyte count fell to within normal limits before the absolute PTA-lymphocyte count.In one patient who was followed for almost a year, the absolute PTA- lymphocyte count was consistently elevated (Figure 2). The estimation of absolute PTA-lymphocyte counts was determined to be valid after a morphometric analysis of the cellular areas occupied by PTA during the acute and convalescent phases of the disease revealed no statistical differences.

Polarity Determination in Sphalerite and Wurtzite Structures

1990 ◽  
Vol 48 (2) ◽  
pp. 500-501
Author(s):  
Stuart McKernan ◽  
C. Barry Carter
Keyword(s):  
Opposite Polarity ◽  
Single Domain ◽  
Polar Material ◽  
Electron Microscopic ◽  
Dynamical Interaction ◽  
X Ray ◽  
Polarity Determination ◽  
The Absolute ◽  
Microscopic Techniques

The determination of the absolute polarity of a polar material is often crucial to the understanding of the defects which occur in such materials. Several methods exist by which this determination may be performed. In bulk, single-domain specimens, macroscopic techniques may be used, such as the different etching behavior, using the appropriate etchant, of surfaces with opposite polarity. X-ray measurements under conditions where Friedel’s law (which means that the intensity of reflections from planes of opposite polarity are indistinguishable) breaks down can also be used to determine the absolute polarity of bulk, single-domain specimens. On the microscopic scale, and particularly where antiphase boundaries (APBs), which separate regions of opposite polarity exist, electron microscopic techniques must be employed. Two techniques are commonly practised; the first [1], involves the dynamical interaction of hoLz lines which interfere constructively or destructively with the zero order reflection, depending on the crystal polarity. The crystal polarity can therefore be directly deduced from the relative intensity of these interactions.

516: A Simplified Method to Estimate the Absolute Renal Uptake of 99MTC-DMSA: Evaluation with a New Model using the Radioactivity of Nephrectomy Specimens as Reference

2005 ◽  
Vol 173 (4S) ◽  
pp. 140-141
Author(s):  
Mariana Lima ◽  
Celso D. Ramos ◽  
Sérgio Q. Brunetto ◽  
Marcelo Lopes de Lima ◽  
Carla R.M. Sansana ◽  
...  
Keyword(s):  
New Model ◽  
Renal Uptake ◽  
Simplified Method ◽  
The Absolute

Translocation Relative to Range

Methodology ◽  
2008 ◽  
Vol 4 (3) ◽  
pp. 132-138 ◽  
Author(s):  
Michael Höfler
Keyword(s):  
Risk Difference ◽  
Binary Outcomes ◽  
Number Needed To Treat ◽  
Likert Scales ◽  
Psychological Science ◽  
The Absolute ◽  
The Difference ◽  
Variance Parameters ◽  
Standardized Index ◽  
Maximum Possible Magnitude

A standardized index for effect intensity, the translocation relative to range (TRR), is discussed. TRR is defined as the difference between the expectations of an outcome under two conditions (the absolute increment) divided by the maximum possible amount for that difference. TRR measures the shift caused by a factor relative to the maximum possible magnitude of that shift. For binary outcomes, TRR simply equals the risk difference, also known as the inverse number needed to treat. TRR ranges from –1 to 1 but is – unlike a correlation coefficient – a measure for effect intensity, because it does not rely on variance parameters in a certain population as do effect size measures (e.g., correlations, Cohen’s d). However, the use of TRR is restricted on outcomes with fixed and meaningful endpoints given, for instance, for meaningful psychological questionnaires or Likert scales. The use of TRR vs. Cohen’s d is illustrated with three examples from Psychological Science 2006 (issues 5 through 8). It is argued that, whenever TRR applies, it should complement Cohen’s d to avoid the problems related to the latter. In any case, the absolute increment should complement d.

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