Effects of a cancer prevention education program on elementary school students' knowledge, attitude, self-efficacy, and intentions in South Korea.

OBJECTIVES: Most children and adolescents have low levels of cancer knowledge and awareness, and infrequently engage in preventive behaviors. This study examined the effects of a short classroom-based intervention for cancer prevention on knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions of fifth-grade elementary school students. METHODS: The study was based on a pre-post-follow-up, 2-group, quasi-experimental design. Participants in the intervention group attended two 40-minute sessions on cancer prevention education and watched a music video about cancer prevention, while participants in the control group were only exposed to the music video. Self-reported knowledge, attitude toward cancer preventability, self-efficacy, and behavioral intentions were assessed 1 week pre-intervention and post-intervention, as well as 3 months post-intervention. RESULTS: The 3-month post-intervention results revealed partial effects, indicating that the education intervention improved knowledge and attitudes toward cancer preventability; however, no effects were observed on self-efficacy and behavioral intentions 3 months after the intervention. CONCLUSIONS: Long-term regular booster sessions are required to improve not only social-cognitive factors, but also behavioral intentions, which could result in behavior changes promoting cancer prevention.

Dielectric functions of solution-processed GdAlO(x)/Si films measured with vacuum ultra-violet spectroscopic ellipsometry.

The dielectric functions of amorphous GdAlO(x) (GAO) films grown by the sol-gel process were investigated from 1.12 to 8.5 eV as a function of annealing temperature using spectroscopic ellipsometry (SE). A GAO precursor sol with a molar ratio of Gd:Al = 1:1 was prepared. Thin layers were formed by spin-coating on p-type Si substrates. The layers were sintered at 400 degrees C for 2 h in an ambient atmosphere, then rapid-thermal-annealed (RTA) at 700 or 800 degrees C for 1 min in an N2 ambient. The optical properties were measured via variable angle SE, at room temperature. The angle of incidence was varied from 50 to 70 degrees in 10 degrees steps. The dielectric functions of the resulting GAO films were obtained from the measured pseudodielectric functions by multilayer-structure calculations using the Tauc-Lorentz (TL) dispersion relation. The real and imaginary parts of the dielectric functions were found to increase with increasing RTA temperature. The film thicknesses and TL parameters (threshold energy E(g) and broadening C) decrease with increasing RTA temperature.

Investigation of the dielectric function of solution-processed InGaZnO films using ellipsometry.

The optical properties of InGaZnO (IGZO) films grown through the sol-gel process as a function of sintering time were investigated with spectroscopic ellipsometry (SE). The IGZO precursor sol was prepared by mixing In nitrate, Ga nitrate, and Zn acetate at a molar ratio of In:Ga:Zn = 3:1:1. The solution was deposited on a SiO2/Si substrate via spin coating. Sintering was performed at 400 degrees C for 1-15 h in an ambient atmosphere. The optical properties were measured over the range 1.12-6.52 eV via variable angle SE, at room temperature. The angle of incidence was varied from 50 to 70 degrees in 5 degree steps. To extract the pure optical properties of IGZO, multilayer-structure calculation with Tauc-Lorentz dispersion relation for IGZO was performed. The changes in the dielectric function of the IGZO films with varying sintering time were observed. The resultant optical properties can be related to the concentration of oxygen vacancies in the material, which can be controlled by the sintering time.

Investigation of the crystallization of amorphous Si by imaging ellipsometry.

We report results on a study of the formation of polycrystalline Si by thermally annealing amorphous Si films. The crystallization of amorphous Si is of increasing interest not only from a basic-physics point of view but also for its wide application in the semiconductor device area. The amorphous Si was deposited on a glass substrate coated with buffer layers and a small amount of Ni to stimulate crystallization. The process was followed with a spatial resolution of 3 microm using an imaging ellipsometer. Imaging ellipsometry constructs sample images from the differences in dielectric functions in different regions. In particular, we can easily detect the polycrystalline Si domains in an amorphous matrix. Results are shown as three-dimensional plots. These are then analyzed to show that the interfaces between domains are not abrupt, and that crystallization within the polycrystalline Si regions is not complete. The fundamental crystallization mechanism is the radial expansion of Ni-seeded needles, forming macroscopic disk-like domains.

Optical study of Mn-doped Bi4Ti3O,12 thin films by spectroscopic ellipsometry.

Mn-doped Bi4Ti3O12(B4T3) thin films grown at 400 degrees C on a Pt/Ti/SiO2/Si substrate through pulsed laser deposition (PLD) were analyzed via spectroscopic ellipsometry (SE). The PLD targets were produced through the conventional solid-state sintering method, and the film samples were annealed at 600 degrees C. The SE spectra of B4T3 films were measured using a rotating analyzer type ellipsometer within the 1.12 to 6.52 eV energy range, with the various incidence angles. The optical properties of the B4T3 films with increasing Mn-mol concentration were extracted using a multilayer model for the whole structure and the Tauc-Lorentz (TL) dispersion relation for the B4T3 film layer. The analysis results clearly showed that the significant changes in optical properties of B4T3 films are caused by thermal annealing procedure and the Mn-mol concentrations. X-ray diffraction (XRD) measurement was also performed to confirm the results of SE analysis.

Imaging of collapsed fatty acid films at air-water interfaces.

In situ imaging ellipsometry is employed to monitor the morphology of collapsed films of fatty acid Langmuir monolayers on pure water and on CaCl2 solution. The ellipsometry images reveal the existence of multilayer domains in the collapsed region, and analysis of the images yields the thicknesses of these domains. The multilayer films formed on water are mainly trilayers, while those on CaCl2 solution are mainly bilayers. The structure of the collapsed films also changes sensitively depending on the history of compression of the molecular layer.