New measurement and evaluation of the excitation function of Ni(p,n) reaction for the production of Cu

One of the radioisotopes for which a growing interest exists in nuclear medicine is ⁶⁴Cu. Its branched decay makes it suitable for both diagnostic and therapeutic purposes. Activation cross sections of the proton induced reaction on enriched ⁶⁴Ni have been studied using the stacked foil technique up to 24 MeV. The experimental cross sections are compared with values available from literature. Thick target yields, based on the discrete measured values of the cross sections are calculated and allow a better estimation of the optimum production parameters.     

THERMALLY INDUCED VIBRATIONS OF COMPOSITE BEAMS WITH INTERLAYER SLIP

Thermally excited vibrations of composite viscoelastic two-layer beams with interfacial slip are analyzed. Geometrically linearized conditions are considered, and the Bernoulli-Euler hypothesis is applied to each layer. At the interface a linear viscoelastic slip law is assigned. The resulting sixth-order initial boundary value problem of the deflection is solved in the time domain by separating the dynamic response in a quasistatic and a complementary dynamic portions. The quasistatic solution is determined in closed form, and the remaining complementary dynamic part is approximated by a truncated modal series that exhibits accelerated convergence. Numerical results are obtained for single-span composite beams with interlayer slip by means of a time-stepping procedure based on the linear interpolation of the driving terms within the time intervals.     

Pr-doped ZBLA fluoride glasses for visible laser emission

Praseodymium doped Fluoride glasses were studied in order to fabricate compact solid state laser sources emitting in the visible range for lighting application and for quantum information processing. The objective of this study is focused on red, green and orange emissions. ZBLA bulk glasses (57%ZrF₄ - 34%BaF₂ - (5 − x)%LaF₃ - 4%AlF₃ - x%PrF₃) have been synthesized under dry argon atmosphere. Physicochemical and optical properties such as density, glass transition temperature, composition, transmission and refractive index have been investigated. Spectroscopic studies have been performed to optimize the rare earth doping level in order to reach the best compromise respecting a good optical quality, a highest lifetime and efficient emission intensity at 635, 605 and 520 nm. Spectroscopic measurements have been carried out on bulk samples with Pr³⁺ concentrations ranging from 0.1 to 3 mol% and first characterizations of ion exchanged Pr: ZBLA waveguides are reported.     

English speakers attend more strongly than Spanish speakers to manner of motion when classifying novel objects and events.

Three experiments provide evidence that the conceptualization of moving objects and events is influenced by one's native language, consistent with linguistic relativity theory. Monolingual English speakers and bilingual Spanish/English speakers tested in an English-speaking context performed better than monolingual Spanish speakers and bilingual Spanish/English speakers tested in a Spanish-speaking context at sorting novel, animated objects and events into categories on the basis of manner of motion, an attribute that is prominently marked in English but not in Spanish. In contrast, English and Spanish speakers performed similarly at classifying on the basis of path, an attribute that is prominently marked in both languages. Similar results were obtained regardless of whether categories were labeled by novel words or numbered, suggesting that an English-speaking tendency to focus on manner of motion is a general phenomenon and not limited to word learning. Effects of age of acquisition of English were also observed on the performance of bilinguals, with early bilinguals performing similarly in the 2 language contexts and later bilinguals showing greater contextual variation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physiological compliance and team performance

Physiological compliance (PC) refers to the correlation between physiological measures of team members over time. The goals of this study were to examine ways of measuring PC in heart rate variability (HRV) data and the relationship between PC and team performance. Teams were tasked with entering both real and simulated rooms and “shooting” individuals with a weapon and identifying individuals without a weapon. The linear correlation and directional agreement PC methods were shown to be the most sensitive to differences in performance, with greater PC being associated with better performance. The correlation method when applied to a measure of respiratory sinus arrhythmia (RSA) revealed a significant difference between high and low performers (t[8] = −2.31, p = 0.03) and the directional agreement applied to inter-beat-intervals and RSA revealed trend-level differences (t[4.62] = −1.86, p = 0.06 and t[8] = −1.68, p = 0.07). These results suggest that PC may have merit for predicting team performance.     

Thermal effects in packaging high power light emitting diode arrays

The package and system level temperature distributions of a high power (>1 W) light emitting diode (LED) array have been investigated using numerical heat flow models. For this analysis, a thermal resistor network model was combined with a 3D finite element submodel of an LED structure to predict system and die level temperatures. The impact of LED array density, LED power density, and active versus passive cooling methods on device operation were calculated. In order to help understand the role of various thermal resistances in cooling such compact arrays, the thermal resistance network was analyzed in order to estimate the contributions from materials as well as active and passive cooling schemes. Finally, an analysis of a ceramic packaging architecture is performed in order to give insight into methods to reduce the packaging resistance for high power LEDs.     

Metal recovery from jarosite waste – A resin screening study

Work has been carried out screening hydrometallurgical resins for application in the valorization of industrially produced jarosite. Of the seven resins tested, anion exchange resins performed poorly for valuable metal recovery. Purolite S950+ and S957, along with a strong acid resin, show good extraction properties, but are selective for Fe³⁺ over the other (divalent) metals. Purolite S930+ (iminodiacetic acid-functionalized resin) demonstrates selectivity for Cu²⁺ over Fe³⁺, but poor selectivity for Ni²⁺, Zn²⁺, and Co²⁺. Dowex M4195 (bispicolylamine-functionalized resin) demonstrates promise for extracting metals of value away from a mixed metal pregnant liquor solution (PLS). A three-stage column-based recovery process is proposed for jarosite leachate treatment.     

The Role of Thyroid Hormone Signaling in the Prevention of Digestive System Cancers

Thyroid hormones play a critical role in the growth and development of the alimentary tract in vertebrates. Their effects are mediated by nuclear receptors as well as the cell surface receptor integrin α_Vβ₃. Systemic thyroid hormone levels are controlled via activation and deactivation by iodothyronine deiodinases in the liver and other tissues. Given that thyroid hormone signaling has been characterized as a major effector of digestive system growth and homeostasis, numerous investigations have examined its role in the occurrence and progression of cancers in various tissues of this organ system. The present review summarizes current findings regarding the effects of thyroid hormone signaling on cancers of the esophagus, stomach, liver, pancreas, and colon. Particular attention is given to the roles of different thyroid hormone receptor isoforms, the novel integrin α_Vβ₃ receptor, and thyroid hormone-related nutrients as possible protective agents and therapeutic targets. Future investigations geared towards a better understanding of thyroid hormone signaling in digestive system cancers may provide preventive or therapeutic strategies to diminish risk, improve outcome and avert recurrence in afflicted individuals.