Development of an improved toughness hyperpure silica reflective heat shield

High purity three dimensionally woven silica-silica materials were evaluated for use as a tough reflective heat shield for planetary entry probes. A special weave design was selected to minimize light piping effects through the heat shield thickness. Various weave spacings were evaluated for densification efficiency with an 0.7 micron particle size high purity silica. Spectral hemispherical reflectance was measured from 0.2 to 2.5 microns at room temperature. Reflectance increases due to densification and purity of material were measured. Reflectance of 3D hyperpure silica was higher than 3D astroquartz silica for all wavelengths. Mechanical properties were measured in beam flexure and beam shear tests. Results indicated strengths lower than reported for slip cast fused silica. Low strengths were attributed to low densities achieved through vacuum impregnation

Formation of pre-service teachers for religious education through experiential learning: The retreat leaders training program

This article reports on the formation of pre-service teachers for religious education through an experiential learning program called the Retreat Leaders Training Program (RLTP). First, the article examines the need for formation for pre-service RE teachers, especially as the formation relates to the development of three forms of teacher knowledge: content knowledge, pedagogical content knowledge and experiential content knowledge. Second, the article reviews the literature on the role of experiential learning in professional formation and the contribution live-in retreats may make in this formation. Third, the article presents the Retreat Leaders Training Program as an example of the formative influence of a retreat based on experiential learning. Fourth, feedback from pre-service teachers undertaking the 2011 program is reported. Lastly, the article discusses the outcomes of the RLTP and the significance of the program as a key ingredient in the formation of teacher knowledge for religious education

Estimation of tunnel blockage from wall pressure signatures: A review and data correlation

A method is described for estimating low speed wind tunnel blockage, including model volume, bubble separation and viscous wake effects. A tunnel-centerline, source/sink distribution is derived from measured wall pressure signatures using fast algorithms to solve the inverse problem in three dimensions. Blockage may then be computed throughout the test volume. Correlations using scaled models or tests in two tunnels were made in all cases. In many cases model reference area exceeded 10% of the tunnel cross-sectional area. Good correlations were obtained regarding model surface pressures, lift drag and pitching moment. It is shown that blockage-induced velocity variations across the test section are relatively unimportant but axial gradients should be considered when model size is determined

Effects of impingement of rocket exhaust gases and solid particles on a spacecraft Interim report, Mar. 18 - Oct. 25, 1966

Impingement damage to spacecraft from rocket exhaust gases and micron sized metal particle

Ground simulation and tunnel blockage for a jet-flapped, basic STOL model tested to very high lift coefficients

Ground effects experiments and large/small-tunnel interference studies were carried out on a model with a 20-inch (50.8 cm) span wing. The wing, which includes a highly deflected knee-blown flap can be fitted with unflapped tips and slats. A low-mounted tailplane can be fitted to the aft fuselage. Three-component balance meaurements, made with a fixed ground equipped with a single boundary-layer blowing slot, were compared with datum, moving-ground results. Good comparisons were obtained up to model blowing momentum coefficients of approximately two, after which the particular floor blowing settings used proved insufficient to prevent floor separation in the vicinity of the model. Skin friction measurements, taken routinely along the floor centerline, proved invaluable during the analysis of results, and their use is recommended as input to determination of floor BLC setting. A careful investigation was made of pitching moments, including tail-on, close-to-ground cases, with favorable results. Drag proved the most sensitive to the change from a moving to the boundary-layer controlled ground

Wilson loops, geometric operators and fermions in 3d group field theory

Group field theories whose Feynman diagrams describe 3d gravity with a varying configuration of Wilson loop observables and 3d gravity with volume observables at each vertex are defined. The volume observables are created by the usual spin network grasping operators which require the introduction of vector fields on the group. We then use this to define group field theories that give a previously defined spin foam model for fermion fields coupled to gravity, and the simpler quenched approximation, by using tensor fields on the group. The group field theory naturally includes the sum over fermionic loops at each order of the perturbation theory.Comment: 13 pages, many figures, uses psfra

Student ministry: Youth ‘step up’ to lead and serve

This article is about student leadership and service in Catholic secondary schools. Initially the concept of leadership through service is explored with particular reference to the educational setting. The concept of “student ministry” is then considered in the light of this leadership and service. The article subsequently reports on an exploratory research study that focused on the experiences and reflections of principals and selected staff from three Catholic secondary schools involved in student ministry. Their experiences and reflections indicate that student ministry has the capacity to offer all students the chance to develop their leadership potential through acts of service, and accentuate their civic, spiritual, religious and personal formation

Horizontal gene transfer is a significant driver of gene innovation in dinoflagellates

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Genome Biology and Evolution 5 (2013): 2368-2381, doi:10.1093/gbe/evt179.The dinoflagellates are an evolutionarily and ecologically important group of microbial eukaryotes. Previous work suggests that horizontal gene transfer (HGT) is an important source of gene innovation in these organisms. However, dinoflagellate genomes are notoriously large and complex, making genomic investigation of this phenomenon impractical with currently available sequencing technology. Fortunately, de novo transcriptome sequencing and assembly provides an alternative approach for investigating HGT. We sequenced the transcriptome of the dinoflagellate Alexandrium tamarense Group IV to investigate how HGT has contributed to gene innovation in this group. Our comprehensive A. tamarense Group IV gene set was compared with those of 16 other eukaryotic genomes. Ancestral gene content reconstruction of ortholog groups shows that A. tamarense Group IV has the largest number of gene families gained (314–1,563 depending on inference method) relative to all other organisms in the analysis (0–782). Phylogenomic analysis indicates that genes horizontally acquired from bacteria are a significant proportion of this gene influx, as are genes transferred from other eukaryotes either through HGT or endosymbiosis. The dinoflagellates also display curious cases of gene loss associated with mitochondrial metabolism including the entire Complex I of oxidative phosphorylation. Some of these missing genes have been functionally replaced by bacterial and eukaryotic xenologs. The transcriptome of A. tamarense Group IV lends strong support to a growing body of evidence that dinoflagellate genomes are extraordinarily impacted by HGT.J.H.W. was supported by the NSF IGERT Program in Comparative Genomics at the University of Arizona (grant number DGE-0654435). This work was supported by grants from the National Science Foundation (grant numbers OCE-0723498, EF-0732440) and funding provided by the BIO5 Institute at the University of Arizona to J.D.H

Student Ministry: Preparing Young People as Leaders for the 21st Century

Ministry with young people has never been more important. Ever-increasing local, national and global concerns demand that schools must do more than prepare young people as responsible citizens. They must prepare young people as emerging leaders with a civic conscience who proactively seek solutions to issues such as increased poverty, the plight of refugees, terrorism, climate change, and corporate greed. This article is about student ministry. Student ministry, as defined in this article, specifically aims to build leadership capacity in school students. In particular, the article attempts to highlight the distinctiveness of student ministry and those ways it promotes and develops the innate leadership potential of all students. Three other forms of ministry to young people, pastoral ministry, youth ministry and campus ministry, are initially described by way of contrast. An understanding of student ministry follows this description. The need for student ministry in Catholic schools is then explored. The article concludes with a brief outline of the authors pilot study, the findings of which will be presented at the conference

The conduct of Australian Indigenous primary health care research focusing on social and emotional wellbeing: a systematic review

Objectives and importance of study: Values and ethics: guidelines for ethical conduct in Aboriginal and Torres Strait Islander health research (Values and ethics) describes key values that should underpin Aboriginal and Torres Strait Islander (Indigenous)-focused health research. It is unclear how research teams address this document in primary health care research. We systematically review the primary health care literature focusing on Indigenous social and emotional wellbeing (SEWB) to identify how Values and ethics and community preferences for standards of behaviour (local protocols) are addressed during research. Systematic review in accordance with PRISMA Guidelines and MOOSE Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies. We searched four databases and one Indigenous-specific website for qualitative, quantitative and mixed-method studies published since Values and ethics was implemented (2003). Included studies were conducted in primary health care services, focused on Indigenous SEWB and were conducted by research teams. Using standard data extraction forms, we identified actions taken (reported by authors or identified by us) relating to Values and ethics and local protocols. A total of 25 studies were included. Authors of two studies explicitly mentioned the Values and ethics document, but neither reported how their actions related to the document's values. In more than half the studies, we identified at least three actions relating to the values. Some actions related to multiple values, including use of culturally sensitive research processes and involving Indigenous representatives in the research team. Local protocols were rarely reported. Addressing Values and ethics appears to improve research projects. The academic community should focus on culturally sensitive research processes, relationship building and developing the Indigenous research workforce, to facilitate acceptable research that affects health outcomes. For Values and ethics to achieve its full impact and to improve learning between research teams, authors should be encouraged to report how the principles are addressed during research, including barriers and enablers that are encountered