scholarly journals Substance Use Dose Unit

2020 ◽  
Author(s):  
Keyword(s):  
Substance Use ◽  
Dose Unit

Computer averaging of lattice images of poly-4-methyl-pentene-1 (P4mp1): Noise created artifacts

1987 ◽  
Vol 45 ◽  
pp. 388-389
Author(s):  
P. Pradère ◽  
J.F. Revol ◽  
R. St. John Manley
Keyword(s):  
Low Dose ◽  
Polymer Concentration ◽  
Processing System ◽  
Limiting Factor ◽  
Dilute Solution ◽  
New Techniques ◽  
Dose Unit ◽  
Lattice Images ◽  
Dose Imaging ◽  
Imaging Conditions

Although radiation damage is the limiting factor in HREM of polymers, new techniques based on low dose imaging at low magnification have permitted lattice images to be obtained from very radiation sensitive polymers such as polyethylene (PE). This paper describes the computer averaging of P4MP1 lattice images. P4MP1 is even more sensitive than PE (total end point dose of 27 C m-2 as compared to 100 C m-2 for PE at 120 kV). It does, however, have the advantage of forming flat crystals from dilute solution and no change in d-spacings is observed during irradiation.Crystals of P4MP1 were grown at 60°C in xylene (polymer concentration 0.05%). Electron microscopy was performed with a Philips EM 400 T microscope equipped with a Low Dose Unit and operated at 120 kV. Imaging conditions were the same as already described elsewhere. Enlarged micrographs were digitized and processed with the Spider image processing system.

Construct Validity of Sensation Seeking: A Psychometric Investigation

1999 ◽  
Vol 20 (3) ◽  
pp. 155-171 ◽  
Author(s):  
André Beauducel ◽  
Burkhard Brocke ◽  
Alexander Strobel ◽  
Anja Strobel
Keyword(s):  
Substance Use ◽  
Construct Validity ◽  
Psychometric Properties ◽  
Factor Structure ◽  
Sensation Seeking ◽  
German Version ◽  
Trait Theory ◽  
Multilevel Theory ◽  
Sensation Seeking Scale ◽  
Psychometric Investigation

Abstract: Zuckerman postulated a biopsychological multilevel theory of Sensation Seeking, which is part of a more complex multi-trait theory, the Alternative Five. The Sensation Seeking Scale Form V (SSS V) was developed for the measurement of Sensation Seeking. The process of validation of Sensation Seeking as part of a multilevel theory includes analyses of relations within and between several levels of measurement. The present study investigates validity and basic psychometric properties of a German version of the SSS V in a broader context of psychometric traits. - The 120 participants were mainly students. They completed the SSS V, the Venturesomeness- and Impulsiveness-Scales of the IVE, the BIS/BAS-Scales, the ZKPQ and the NEO-FFI. - The results reveal acceptable psychometric properties for the SSS V but with limitations with regard to factor structure. Indications for criterion validity were obtained by prediction of substance use by the subscales Dis and BS. The results of a MTMM analysis, especially the convergent validities of the SSS V were quite satisfying. On the whole, the results yielded sufficient support for the validity of the Sensation Seeking construct or the instrument respectively. They also point to desirable modifications.

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