Optimisation of the Photostimulated Luminescence (PSL) Tests to Detect Irradiated Dietary Supplements: Experimental Studies of Pre-Concentration, Depletion Rate Analysis and Multiwavelength PSL Analysis

No abstract available

Observed distribution functions of H, He, C, O, and Fe in corotating energetic particle streams: Implications for interplanetary acceleration and propagation

Distribution functions for H, He, C, O, and Fe derived from our IMP 8 measurements of approximately 0.15 to approximately 8 MeV/nucleon particles in three corotating streams observed near earth are shown to have a simple exponential dependence on the particle speed. The e-folding speed, v sub o, is typically 0.01c, is found to be the same for the distribution functions of all elements examined, and varies little from one corotating event to the next. The relative abundances of energetic particles in these events resemble most closely the solar coronal composition and, thus, presumably that of the solar wind. These results may imply that the acceleration of these particles, which occurs in corotating interaction regions at several AU from the sun, is by a statistical process

Unconventional critical scaling of magnetization in uranium ferromagnetic superconductors UGe2_2 and URhGe

We report a dc magnetization study of the critical phenomenon around the ferromagnetic transition temperature T_C in high-quality single crystals of uranium ferromagnetic superconductors UGe2 and URhGe. The critical exponents, beta for the temperature dependence of the magnetization below T_C, gamma for the magnetic susceptibility, and delta for the magnetic isothermal at T_C have been determined with a modified Arrott plot, a Kouvel-Fisher plot, and the scaling analysis. Magnetization in the ferromagnetic state has strong uniaxial magnetic anisotropy in the two compounds. However, the universality class of the critical phenomena do not belong to the three dimensional (3D) Ising system. Although the values of beta in UGe2 and URhGe are close to those in the 3D magnets, the values of gamma are close to unity, that expected from the mean field theory. Similar critical exponents have been reported previously for the 3D Ising ferromagnet UIr where superconductivity appears under high pressure. The critical behavior may be limited to a very narrow Ginzburg critical region of 1 mK because of the strong itinerant character of the 5f electrons in the ferromagnetic superconductor UCoGe where the mean field behavior of the magnetization has been reported. The unconventional critical scaling of magnetization in UGe2, URhGe and UIr cannot be explained via previous approaches to critical phenomena. The ferromagnetic correlation between the 5f electrons differs from that in the 3D Ising system and this difference may be a key point for the understanding of the ferromagnetism where superconductivity emerges.Comment: 8 pages, 5 figure

Strong Correlation between Anomalous Quasiparticle Scattering and Unconventional Superconductivity in Hidden Order Phase of URu2_2Si2_2

The pressure dependent electrical resistivity of URu$_2$Si$_2$ has been studied at high pressure across the first order phase boundary of $P_x$ where the ground state switches under pressure from "hidden order" (HO) to large moment antiferromagnetic (LAFM) states. The electrical transport in URu$_2$Si$_2$ at low temperatures shows a strong sample dependence. We have measured an ultra-clean single crystal whose quality is the highest among those used in previous studies. The generalized power law ${\rho}{\,}={\,}{\rho_0}+{\,}{A_n}T{^n}$ analysis finds that the electric transport property deviates from Fermi liquid theory in the HO phase but obeys the theory well above $P_x$. The analysis using the polynomial in $T$ expression ${\rho}{\,}={\,}{\rho_0}+{\,}{{\alpha}_1}T+{\,}{{\alpha}_2}T{^2}$ reveals the relation ${{\alpha}_1}/{{\alpha}_2}$ $\propto$ $T_{sc}$ in the HO phase. While the pressure dependence of ${{\alpha}_2}$ is very weak, ${{\alpha}_1}$ is roughly proportional to $T_{sc}$. This suggests a strong correlation between the anomalous quasiparticle scattering and the superconductivity and that both have a common origin. The present study clarifies a universality of the HO phase inherent in strongly correlated electron superconductors near quantum criticality

Examining the Relationship Between Self-Efficacy and Health Behaviors Among College Students

Adolescents’ transition into adulthood often coincides with significant developmental change processes. Behavioral patterns established during this period can determine risk and quality of life trajectories (Ben-Shlomo & Kuh, 2002, Halfon & Hochstein, 2002). Social support facilitates health behavior change and college students have ready access to peers with shared goals. In addition to social support, self-efficacy has also been associated with student health as a protective and predictive factor of healthy behaviors (Von Ah, Ebert, Ngamvitroj, Park, & Kang, 2004). Research indicates a strong relationship between self-efficacy and health behaviors; however, the direction of causality is unclear and there is little understanding of how self-efficacy changes. The current experiment examined the effects of observational learning/modeling and social support created through course-related, small groups or Accountability Teams (ATs) on individual self-efficacy and physical activity. The primary hypothesis was that individual health self-efficacy of students would interact with types of ATs, affecting students’ general self-efficacy, perception of health, and physical activity. Participants in this experiment were undergraduate students enrolled in a lifelong fitness health course. Self-report measures of health self-efficacy (HSE), general self-efficacy, quality of life, and general health were distributed and completed by participants. Additionally, students submitted measurements of body fat percentage and physical activity (e.g., number of steps taken). Participants were assigned to support groups called “Accountability Teams” within their respective health class. Teams were assigned based on students’ HSE; each group consisted of either matched HSE (i.e., all students were low or high HSE) or mixed health self-efficacy (i.e., students in the AT were a mix of low and high HSE). The results indicate interactions in which students of Hi/Lo HSE respond differently in ATs. Overall, results suggest that LoHSE students placed in matched (homogenous) HSE groups had the best outcomes on multiple dimensions of health and health behaviors, followed by HiHSE students in mixed HSE groups. HiHSE students in matched groups has poor outcomes. The poorest outcomes were for LoHSE students in the mixed AT condition. These results are discussed within a self-efficacy frame and implications for behavioral health courses and therapy are discussed