Processing Method Effects on Solar Diameter Measurements: Use of Data Gathered by the Solar Disk Sextant

Solar Physics ◽  
2008 ◽  
Vol 247 (2) ◽  
pp. 225-248 ◽  
Author(s):  
D. Djafer ◽  
G. Thuillier ◽  
S. Sofia ◽  
A. Egidi
Keyword(s):  
Solar Disk ◽  
Processing Method ◽  
Solar Diameter ◽  
Use Of Data ◽  
Method Effects

OVERCOMING BLACK DROP EFFECT IN HIGH RESOLUTION ASTROMETRY: THE CASE OF SEA SUNSETS

2011 ◽  
Vol 20 (10) ◽  
pp. 2009-2012
Author(s):  
COSTANTINO SIGISMONDI
Keyword(s):  
High Resolution ◽  
Solar Disk ◽  
Contact Time ◽  
Diffraction Limit ◽  
Residual Error ◽  
Sea Surface ◽  
Analytical Function ◽  
The Sun ◽  
Solar Diameter ◽  
First Contact

Planetary transits on the Sun have been used to recover past values of the solar diameter. These results, as in 1832 Mercury transit, are different when different observers and instruments are considered, because of the black drop phenomenon. Sunsets above sea surface (near-zero almucantarat transit) show it clearly: the first contact between solar disk and the horizon is anticipated by luminous connections. The last instant of light is independent on detector's optics when the atmosphere is clear. The first contact time is obtained by fitting to data the analytical function of the intersection between Sun and sea horizon. This correction overcomes the black drop effect almost completely, the last residual error remains below the diffraction limit, as demonstrated by sunset timings.

High-Precision Measurements of the Solar Diameter and Oblateness by the Solar Disk Sextant (SDS) Experiment

Solar Physics ◽  
2006 ◽  
Vol 235 (1-2) ◽  
pp. 407-418 ◽  
Author(s):  
A. Egidi ◽  
B. Caccin ◽  
S. Sofia ◽  
W. Heaps ◽  
W. Hoegy ◽  
...  
Keyword(s):  
High Precision ◽  
Solar Disk ◽  
Precision Measurements ◽  
Solar Diameter

Low-temperature Mo-catalyzed growth of crystalline Si3N4 by CVD

1993 ◽  
Vol 51 ◽  
pp. 918-919
Author(s):  
K.L. More ◽  
R.A. Lowden ◽  
T.M. Besmann
Keyword(s):  
Vapor Deposition ◽  
Hot Isostatic Pressing ◽  
Chemical Vapor ◽  
Processing Method ◽  
Crystalline Material ◽  
Structural Ceramic ◽  
Alternative Processing ◽  
Strong Candidate ◽  
Hot Pressing Sintering ◽  
Processing Techniques

Silicon nitride possesses an attractive combination of thermo-mechanical properties which makes it a strong candidate material for many structural ceramic applications. Unfortunately, many of the conventional processing techniques used to produce Si3N4, such as hot-pressing, sintering, and hot-isostatic pressing, utilize significant amounts of densification aids (Y2O3, Al2O3, MgO, etc.) which ultimately lowers the utilization temperature to well below that of pure Si3N4 and also decreases the oxidation resistance. Chemical vapor deposition (CVD) is an alternative processing method for producing pure Si3N4. However, deposits made at temperatures less than ~1200°C are usually amorphous and at slightly higher temperatures, the deposition of crystalline material requires extremely low deposition rates (~5 μm/h). Niihara and Hirai deposited crystalline α-Si3N4 at 1400°C at a deposition rate of ~730 μm/h. Hirai and Hayashi successfully lowered the CVD temperature for the growth of crystalline Si3N4 by adding TiCl4 vapor to the SiCl4, NH3, and H2 reactants. This resulted in the growth of α-Si3N4 with small amounts of TiN at temperatures as low as 1250°C.

Question Wording Effects in the Assessment of Global Self-Esteem

2000 ◽  
Vol 16 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Martin Dunbar ◽  
Graeme Ford ◽  
Kate Hunt ◽  
Geoff Der
Keyword(s):  
Reading Ability ◽  
Factor Model ◽  
Self Esteem ◽  
Reading Scores ◽  
Poor Reading ◽  
Method Effect ◽  
Two Samples ◽  
Positive Item ◽  
Method Effects ◽  
Best Fit

Summary: Marsh (1996) produced evidence that method effects associated with negatively worded items might be responsible for the results of earlier factor analytic studies that reported finding positive and negative self-esteem factors in the Rosenberg Global self-esteem scale ( Rosenberg, 1965 ). He analyzed data collected from children using a 7-item self-esteem measure. This report details attempts to replicate Marsh 's analysis in data collected from two samples of adults who completed the full 10-item Global Self-Esteem (GSE) scale. The results reported here are similar to those given by Marsh in so much as a correlated uniquenesses model produced a superior fit to the data than the simple one factor model (without correlated uniquenesses) or the often reported two factor (positive and negative self-esteem) model. However, whilst Marsh reported that the best fit was produced by allowing negative item uniquenesses to correlate with each other, the model that produced the best fit to these data was one that contained correlated positive item uniquenesses. Supporting his claim that differential responding to negative and positive self-esteem items reflects a method effect associated with reading ability, Marsh also showed that factors associated with negative and positive items were most distinct among children who had poor reading scores. We report a similar effect among a sample of older adults where the correlation between these factors was compared across two groups who were selected according to their scores on a test of verbal reasoning.

Mindfulness or Mindlessness?

2011 ◽  
Vol 27 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Volkmar Höfling ◽  
Helfried Moosbrugger ◽  
Karin Schermelleh-Engel ◽  
Thomas Heidenreich
Keyword(s):  
Construct Validity ◽  
Model Fit ◽  
Factor Analyses ◽  
Confirmatory Factor Analyses ◽  
Mindful Attention ◽  
Confirmatory Factor ◽  
Item Wording ◽  
Method Effects

The 15 items of the Mindful Attention and Awareness Scale (MAAS; Brown & Ryan, 2003 ) are negatively worded and assumed to assess mindfulness. However, there are indications of differences between the original MAAS and a version with the positively rephrased MAAS items (“mirror items”). The present study examines whether the mindfulness facet “mindful attention and awareness” (MAA) can be measured with both positively and negatively worded items if we take method effects due to item wording into account. To this end, the 15 negatively worded items of the MAAS and additionally 13 positively rephrased items were assessed (N = 602). Confirmatory factor analyses (CFA) models with and without regard to method effects were carried out and evaluated by means of model fit. As a result, the positively and negatively worded items should be seen as different methods that influence the construct validity of mindfulness. Furthermore, a modified version of the MAAS (MAAS-Short) with five negatively worded items (taken from the MAAS) and five positively worded items (“mirror items”) was introduced as an alternative to assess MAA. The MAAS-Short appears superior to the original MAAS. The results and the limitations of the present study are discussed.

The Beck Hopelessness Scale

2016 ◽  
Vol 32 (2) ◽  
pp. 111-118 ◽  
Author(s):  
Marianna Szabó ◽  
Veronika Mészáros ◽  
Judit Sallay ◽  
Gyöngyi Ajtay ◽  
Viktor Boross ◽  
...  
Keyword(s):  
Binary Data ◽  
Factor Model ◽  
Clinical Sample ◽  
Analytical Techniques ◽  
Cross Cultural ◽  
Cultural Validity ◽  
Beck Hopelessness Scale ◽  
Method Effects ◽  
Hungarian Population ◽  
Components Analysis

Abstract. The aim of the present study was to examine the construct and cross-cultural validity of the Beck Hopelessness Scale (BHS; Beck, Weissman, Lester, & Trexler, 1974 ). Beck et al. applied exploratory Principal Components Analysis and argued that the scale measured three specific components (affective, motivational, and cognitive). Subsequent studies identified one, two, three, or more factors, highlighting a lack of clarity regarding the scale’s construct validity. In a large clinical sample, we tested the original three-factor model and explored alternative models using both confirmatory and exploratory factor analytical techniques appropriate for analyzing binary data. In doing so, we investigated whether method variance needs to be taken into account in understanding the structure of the BHS. Our findings supported a bifactor model that explicitly included method effects. We concluded that the BHS measures a single underlying construct of hopelessness, and that an incorporation of method effects consolidates previous findings where positively and negatively worded items loaded on separate factors. Our study further contributes to establishing the cross-cultural validity of this instrument by showing that BHS scores differentiate between depressed, anxious, and nonclinical groups in a Hungarian population.

Trait and method effects in employment interview dimension ratings

2003 ◽  
Author(s):  
James M. Conway ◽  
Allen I. Huffcutt ◽  
Bridget Settino
Keyword(s):  
Employment Interview ◽  
Method Effects
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