Microstructure evolution of Al–Mg–B thin films by thermal annealing

The growth of Al–Mg–B thin films on SiO2/Si(100) substrates was performed by nanosecond pulsed laser deposition at three different substrate temperatures (300 K, 573 K, and 873 K). The as-deposited films were then annealed at 1173 K or 1273 K for 2 h. X-ray photoelectron spectroscopy,x-ray diffraction(XRD), and atomic force microscope were employed to investigate the effects of processing conditions on the composition, microstructure evolution, and surface morphology of the Al–Mg–B films. The substrate temperatures were found to affect the composition of as-deposited films in that the Mg content decreases and C content increases at higher substrate temperatures, in particular for the 873 K-deposited film.XRD results show that the as-deposited films were amorphous, and this structure may be stable up to 1173 K. Annealing at 1273 K was found to fully crystallize the room temperature and 573 K-deposited Al–Mg–B films with the formation of the polycrystalline orthorhombic AlMgB14 phase, accompanied by the development of a pronounced (011) preferred orientation. Nevertheless, high C incorporation in the 873 K-deposited Al–Mg–B film inhibits the crystallization and the amorphous structure remains stable even during 1273 K annealing. The presence of Si in the room-temperature-deposited 1273 K-annealed film due to the interdiffusion between the substrate and film leads to the formation of an additional tetragonal α-FeSi2 phase, which is thought to cause the surface cracking and microstructural instability observed in this film

Electrical transport in amorphous semiconducting AlMgB14 films

The electrical transport properties of semiconducting AlMgB14films deposited at room temperature and 573K are reported in this letter. The as-deposited films are amorphous, and they exhibit high n-type electrical conductivity, which is believed to stem from the conduction electrons donated by Al, Mg, and/or Fe impurities in these films. The film deposited at 573K is less conductive than the room-temperature-deposited film. This is attributed to the nature of donor or trap states in the band gap related to the different deposition temperatures

Predictors of medication-related problems among medicaid patients participating in a pharmacist-provided telephonic medication therapy management program

STUDY OBJECTIVE: To identify predictors of medication-related problems (MRPs) among Medicaid patients participating in a telephonic medication therapy management (MTM) program. DESIGN: Retrospective analysis of data from patients enrolled in a previously published study. DATA SOURCES: Two Medicaid administrative claims file databases (for health care utilization and prescription dispensing information) and one pharmacy organization file for MTM program information. PATIENTS: Seven hundred twelve adult Medicaid patients who participated in a statewide pharmacist-provided telephone-based MTM program and who received an initial medication therapy review. MEASUREMENTS AND MAIN RESULTS: The primary dependent variable was the number of MRPs detected during the initial medication therapy review. Secondary dependent variables were the detection of one or more MRPs related to indication, effectiveness, safety, and adherence. Predictor variables were selected a priori that, from the literature and our own practice experiences, were hypothesized as being potentially associated with MRPs: demographics, comorbidities, medication use, and health care utilization. Bivariate analyses were performed, and multivariable models were constructed. All predictor variables with significant associations (defined a priori as p<0.1) with the median number of MRPs detected were then entered into a three-block multiple linear regression model. The overall model was significant (p<0.001, R(2) = 0.064). Significant predictors of any MRPs (p<0.05) were total number of medications, obesity, dyslipidemia, and one or more emergency department visits in the past 3 months. For indication-related MRPs, the model was significant (p<0.001, R(2) = 0.049), and predictors included female sex, obesity, dyslipidemia, and total number of medications (p<0.05). For effectiveness-related MRPs, the model was significant (p<0.001, R(2) = 0.054), and predictors included bone disease and dyslipidemia (p<0.05). For safety-related MRPs, the model was significant (p<0.001, R(2) = 0.046), and dyslipidemia was a predictor (p<0.05). No significant predictors of adherence-related MRPs were identified. CONCLUSION: This analysis supports the relative importance of number of medications as a predictor of MRPs in the Medicaid population and identifies other predictors. However, given the models' low R(2) values, these findings indicate that other unknown factors are clearly important and that criteria commonly used for determining MTM eligibility may be inadequate in identifying appropriate patients for MTM in a Medicaid population

Direct and mediated effects of a social-emotional and character development program on adolescent substance use

Mitigating and preventing substance use among adolescents requires approaches that address the multitude of factors that influence this behavior. Such approaches must be tested, not only for evidence of empirical effectiveness, but also to determine the mechanisms by which they are successful. The aims of the present study were twofold: 1) To determine the effectiveness of a school-based social-emotional and character development (SECD) program, Positive Action (PA), in reducing substance use (SU) among a sample of U.S. youth living in a low-income, urban environment, and 2) to test one mechanism by which the program achieves its success. We used longitudinal mediation analysis to test the hypotheses that: 1) students attending PA intervention schools engage in significantly less SU than students attending control schools, 2) students attending PA intervention schools show significantly better change in SECD than students attending control schools, and 3) the effect of the PA intervention on SU is mediated by the change in SECD. Analyses revealed program effects on both SECD and SU, a relationship between SECD and SU, and the effects of PA on SU were completely mediated by changes in SECD. Future research directions and implications for schoolbased social-emotional and character development efforts and substance use prevention are addressed.peer-reviewe

Statistical Communication Theory

Contains reports on six research projects.National Science Foundation (Grant GP-2495)National Institutes of Health (Grant MH-04737-04)National Aeronautics and Space Administration (Grant NsG-496

Abstract This study applied the Model of Acidification

of Groundwater in Catchments (MAGIC) to estimate the sensitivity of 66 watersheds in the Southern Blue Ridge Province of the Southern Appalachian Mountains, United States, to changes in atmospheric sulfur (S) deposition. MAGIC predicted that stream acid neutralizing capacity (ANC) values were above 20 μeq/L in all modeled watersheds in 1860. Hindcast simulations suggested that the media

Ohta-Jasnow-Kawasaki Approximation for Nonconserved Coarsening under Shear

We analytically study coarsening dynamics in a system with nonconserved scalar order parameter, when a uniform time-independent shear flow is present. We use an anisotropic version of the Ohta-Jasnow-Kawasaki approximation to calculate the growth exponents in two and three dimensions: for d=3 the exponents we find are the same as expected on the basis of simple scaling arguments, that is 3/2 in the flow direction and 1/2 in all the other directions, while for d=2 we find an unusual behavior, in that the domains experience an unlimited narrowing for very large times and a nontrivial dynamical scaling appears. In addition, we consider the case where an oscillatory shear is applied to a two-dimensional system, finding in this case a standard t^1/2 growth, modulated by periodic oscillations. We support our two-dimensional results by means of numerical simulations and we propose to test our predictions by experiments on twisted nematic liquid crystals.Comment: 25 RevTeX pages, 7 EPS figures. To be published in Phys. Rev.