Research and development program on magnetic electrical conductor, electrical insulation, and bore seal materials - Electrical conductor and electrical insulation materials topical report

Electrical, mechanical, and thermo-physical properties of conductor and insulation materials for application to advanced space electric power system

Use of combinatorial analysis for the study of new material for solar cells applications

This paper presents a combinatorial method for the deposition and characterization of new metallic precursors for photovoltaic materials. Onedimensional thin film alloy “libraries” were electrodeposited on Mo-coated glass. The library elements were deposited in two consecutive baths and then heated in a reducing atmosphere to promote interdiffusion of the elements. At the end of this process, the libraries possessed a composition gradient along their lengths, with single elements at their two opposite ends and one or more alloys and/or a solid state solution in between. This continuous range of compositions can therefore be considered a collection of specific precursors that can be interrogated by examining their corresponding locations, with the crystallographic structure along the library changing in accordance with the phase diagram for the metals. The libraries were then sulphurised or selenised by heating in a sulphur-rich or selenium rich atmosphere; this converted the metallic precursors in a continuous range of materials, candidates for potential solar cells absorbers. The libraries were analysed by X-ray diffraction and energy dispersive X-ray spectrometry. The X-ray diffraction results show phase changes across the libraries, which can be correlated with the original precursor concentration at that particular p

Thermal and Non-thermal Plasmas in the Galaxy Cluster 3C 129

We describe new Chandra spectroscopy data of the cluster which harbors the prototypical "head tail" radio galaxy 3C 129 and the weaker radio galaxy 3C 129.1. We combined the Chandra data with Very Large Array (VLA) radio data taken at 0.33, 5, and 8 GHz (archival data) and 1.4 GHz (new data). We also obtained new HI observations at the Dominion Radio Astrophysical Observatory (DRAO) to measure the neutral Hydrogen column density in the direction of the cluster with arcminute angular resolution. The Chandra observation reveals extended X-ray emission from the radio galaxy 3C 129.1 with a total luminosity of 1.5E+41 erg/s. The X-ray excess is resolved into an extended central source of ~2 arcsec (1 kpc) diameter and several point sources with an individual luminosity up to 2.1E+40 erg/s. In the case of the radio galaxy 3C 129, the Chandra observation shows, in addition to core and jet X-ray emission reported in an earlier paper, some evidence for extended, diffuse X-ray emission from a region east of the radio core. The 12 arcsec x 36 arcsec (6 kpc x 17 kpc) region lies "in front" of the radio core, in the same direction into which the radio galaxy is moving. We use the radio and X-ray data to study in detail the pressure balance between the non-thermal radio plasma and the thermal Intra Cluster Medium (ICM) along the tail of 3C 129 which extends over 15 arcmin (427 kpc). Depending on the assumed lower energy cutoff of the electron energy spectrum, the minimum pressure of the radio plasma lies a factor of between 10 and 40 below the ICM pressure for a large part of the tail. We discuss several possibilities to explain the apparent pressure mismatch.Comment: Accepted for publication in MNRAS. Refereed manuscript. 14 pages, 8 figures, additional panel of Fig. 3 shows asymmetric ICM distributio

Connecting the Old to the New: What Technology-Crazed Adolescents tell us about Teaching Content Area Literacy

This article describes a study where Personal Digital Assistants (PDAs) were integrated into two eighth grade social studies classrooms to create a bridge that connected traditional textbook teaching with new technology. This article will explore the motivation for this type of integration, give specific details about the study, and share what we learned from students about how using the technology gave them control over their reading, connected to their lives, and gave a new spin on the old in terms of content area literacy strategies. Finally, this article will conclude with future directions for educational implications for research and practice

Forces between functionalized silica nanoparticles in solution

To prevent the flocculation and phase separation of nanoparticles in solution, nanoparticles are often functionalized with short chain surfactants. Here we present fully-atomistic molecular dynamics simulations which characterize how these functional coatings affect the interactions between nanoparticles and with the surrounding solvent. For 5 nm diameter silica nanoparticles coated with poly(ethylene oxide) (PEO) oligomers in water, we determined the hydrodynamic drag on two approaching nanoparticles moving through solvent and on a single nanoparticle as it approaches a planar surface. In most circumstances, acroscale fluid theory accurately predicts the drag on these nano-scale particles. Good agreement is seen with Brenner's analytical solutions for wall separations larger than the soft nanoparticle radius. For two approaching coated nanoparticles, the solvent-mediated (velocity-independent) and lubrication (velocity-dependent) forces are purely repulsive and do not exhibit force oscillations that are typical of uncoated rigid spheres.Comment: 4 pages, 3 fig

Group Approach to Narrative Therapy: A Review of the Literature

This article is a review of the current literature on the application of Narrative Therapy (NT) to a group setting. Sixteen peer-reviewed articles were found using the search terms narrative, group, and therapy. Databases used include Science Direct, Social Sciences Citation Index, PsychINFO, CINAHL Plus, ERIC, SocINDEX, and EBSCOhost. The articles describe the composition and efficacy of various groups that utilized NT to treat children, adults, and older adults. Narrative Group Therapy (NGT) was utilized for substance abuse, body image concerns, social phobia, grief associated with acquired brain injury, physical and sexual abuse and neglect, attention deficit/hyperactivity disorder, intimacy within couples, transition out of homelessness, depression, anxiety, trauma, and severe mental illnesses. This review of the literature highlights the benefits and limitations of using NGT and offers a suggested direction for continued study

The susceptibility of roots to infection by an arbuscular mycorrhizal fungus in relation to age and phosphorus supply

An apparatus in which plant roots may be challenged uniformly with inoculum of arbuscular mycorrhizal fungi is described. Seedlings of leek (Allium porrum L.) or clover (Trifolium repens L.) were first grown non-symbiotically in the apparatus for 21 d at three rates of phosphorus (P) addition to soil (1 50 (PI), 450 (P3) and 750 (P5) mg P kg-1 soil). The positions of individual root tips were recorded, and the root systems then challenged with inoculum of Glomus mosseae (Nicol & Gerd.) Gerdemann & Trappe. Roots were excised 14 d later, and the probability of occurrence of internal infection in successive 3 mm (clover) or 5 mm (leek) sections of root was estimated in first-order laterals (clover) or main axes (leek) from the proportion of sections at each location of replicate roots that bore internal fungal structures. Only in the region of a root proximal to the position of the root tips at inoculation could data be used to investigate change of probability of infection with cell age. Here, there were sharp declines in probability of infection with proximal distance, in both hosts and in all P treatments. The decline of probability was greater in clover: when expressed in terms of cell age at the time of challenge, there was no infection at Pl in cells > 10 d old in leek and none in cells > 7 d old in clover. Models of the form log(e) [p(i)/(1-p(i))] = alpha + beta x distance, where p(i) is the estimated probability of infection and alpha and beta are constants, were fitted to these data. The odds on infection are [p(i)/(1-p(i))]. For leek, 8 was unaltered by P addition (P3 and P5 curves were parallel to P1) but from alpha it could be calculated that on average the odds on successful infection at any particular distance were reduced by 3 7 % and 70 % by P3 and P5 rates of P addition respectively. In clover the curves for the three P treatments were not parallel. Addition of P appeared to reduce the odds on infection of clover much more than those of leek. We conclude that the simplest explanation for the patterns of infection in leek is that P addition increased the time taken for soil inoculum of G. mosseae to infect roots: the mechanism in clover might be more complex