2,512 research outputs found

    LSA silicon material task closed-cycle process development

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    The initial effort on feasibility of the closed cycle process was begun with the design of the two major items of untested equipment, the silicon tetrachloride by product converter and the rotary drum reactor for deposition of silicon from trichlorosilane. The design criteria of the initial laboratory equipment included consideration of the reaction chemistry, thermodynamics, and other technical factors. Design and construction of the laboratory equipment was completed. Preliminary silicon tetrachloride conversion experiments confirmed the expected high yield of trichlorosilane, up to 98 percent of theoretical conversion. A preliminary solar-grade polysilicon cost estimate, including capital costs considered extremely conservative, of $6.91/kg supports the potential of this approach to achieve the cost goal. The closed cycle process appears to have a very likely potential to achieve LSA goals

    Determining the feasibility of chemical vapor deposition process for the production of dispersoid strengthened chromium alloys Final report

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    Chemical vapor deposition process for production of high purity chromium metal containing thorium oxide dispersion materia

    Dinosaur tracks from the Kilmaluag Formation (Bathonian, Middle Jurassic) of Score Bay, Isle of Skye, Scotland, UK

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    Tracks of a juvenile theropod dinosaur with footprint lengths of between 2 and 9 cm as well as adults of the same ichnospecies with footprints of about 15–25 cm in length were found in the Bathonian (Middle Jurassic) Kilmaluag Formation of Score Bay, northwestern Trotternish Peninsula, Isle of Skye, Scotland, UK. Two footprint sizes occur together on the same bedding plane in the central portion of Score Bay, both in situ and on loose blocks. Another horizon containing footprints above this was also identified. The footprints from the lowest horizon were produced in a desiccated silty mud that was covered with sand. A close association of both adults and juveniles with similar travel direction indicated by the footprints may suggest post-hatching care in theropod dinosaurs. Other footprints, produced on a rippled sandy substrate, have been found on the slightly higher bedding plane at this locality. Loose blocks found 130 m to the northeast in the central part of Score Bay have not been correlated with any in situ sediments, but were preserved in a similar manner to those from the higher bedding plane. These tracks represent the youngest dinosaur remains yet found in Scotland

    HIV type 1 that select tRNA(His) or tRNA(Lys1,2) as primers for reverse transcription exhibit different infectivities in peripheral blood mononuclear cells.

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    The replication in human peripheral blood mononuclear cells (PBMC) of unique HIV-1 that select tRNA(His) or tRNA(Lys1,2) for reverse transcription was compared to the wild-type virus that uses tRNA(Lys,3). HIV-1 with only the primer-binding site (PBS) changed to be complementary to these alternative tRNAs initially replicated more slowly than the wild-type virus in PBMC, although all viruses eventually reached equivalent growth as measured by p24 antigen. Viruses with only a PBS complementary to the 3' terminal 18 nucleotides of tRNA(His) or tRNA(Lys1,2) reverted to use tRNA(Lys3). HIV-1 with mutations in the U5-PBS to allow selection of tRNA(His) and tRNA(Lys1,2) following long-term growth in SupT1 cells were also evaluated for growth and PBS stability following replication in PBMC. Although both viruses initially grew slower than wild type, they maintained a PBS complementary to the starting tRNA and did not revert to the wild-type PBS after long-term culture in PBMC. Analysis of the U5-PBS regions following long-term culture in PBMC also revealed few changes from the starting sequences. The virus that stably used tRNA(His) was less infectious than the wild type. In contrast, the virus that stably used tRNA(Lys1,2) evolved to be as infectious as wild-type virus following extended culture in PBMC. The results of these studies highlight the impact of the host cell on the tRNA primer selection process and subsequent infectivity of HIV-1

    Access to and experience of education for children and adolescents with cancer: a scoping review protocol

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    BACKGROUND: Cancer diagnosis in childhood or adolescence impacts significantly on school attendance, experience and educational outcomes. While there is longstanding recognition in clinical practice that these effects span the whole illness trajectory and continue beyond treatment completion, further clarity is required on the specific barriers and facilitators to education during cancer treatment and beyond, as well as on the experiences of children and adolescents across the full range of education settings (hospital, home, virtual, original school of enrolment), in order to determine which interventions are successful in improving access and experience from their perspective. The aim of this review is to identify what is known from the existing literature about access to and experience of education for children and adolescents with cancer during and post treatment. METHODS: We have planned a scoping literature review searching the following databases from inception onwards: MEDLINE (Ovid), Embase and Embase Classic, Web of Science Core Collection, Education Resources Index, Sociological Abstracts, APA PsycINFO, SCOPUS, CINAHL Plus, Emcare and The Cochrane Library. In addition, DARE, conference abstracts, key journals, and institutional websites will be searched. Arksey and O'Malley's six-step process will be followed, including a consultation exercise. Studies, reports and policies from any country providing care and treatment for children and adolescents with cancer published in English will be considered eligible for inclusion. Two reviewers will independently screen all citations, full-text articles and abstract data. A narrative summary of findings will be conducted. Data analysis will involve quantitative (e.g., frequencies) and qualitative (e.g., content and thematic analysis) methods. DISCUSSION: This is a timely examination given the increased incidence of childhood cancer, more intensive treatment regimens and improved survival rates for childhood cancer. The inclusion of a substantive consultation exercise with families and professionals will provide an important opportunity to examine the scoping review outputs. Findings will assist the childhood cancer community in developing a comprehensive evidence-based understanding of a significant associated bio-psychosocial impact of cancer diagnosis and treatment and will form the first step towards developing effective interventions and policies to mitigate identified detrimental effects. SYSTEMATIC REVIEW REGISTRATION: Open Science Framework (osf/io/yc4wt)

    Low cost silicon solar arrays

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    The economic production of silicon solar cell arrays circumvents p-n junction degradation by nuclear doping, in which the Si-30 transmutes to P-31 after thermal neutron capture. Also considered are chemical purity specifications for improved silicon bulk states, surface induced states, and surface states

    CMS Monte Carlo production in the WLCG computing Grid

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    Monte Carlo production in CMS has received a major boost in performance and scale since the past CHEP06 conference. The production system has been re-engineered in order to incorporate the experience gained in running the previous system and to integrate production with the new CMS event data model, data management system and data processing framework. The system is interfaced to the two major computing Grids used by CMS, the LHC Computing Grid (LCG) and the Open Science Grid (OSG). Operational experience and integration aspects of the new CMS Monte Carlo production system is presented together with an analysis of production statistics. The new system automatically handles job submission, resource monitoring, job queuing, job distribution according to the available resources, data merging, registration of data into the data bookkeeping, data location, data transfer and placement systems. Compared to the previous production system automation, reliability and performance have been considerably improved. A more efficient use of computing resources and a better handling of the inherent Grid unreliability have resulted in an increase of production scale by about an order of magnitude, capable of running in parallel at the order of ten thousand jobs and yielding more than two million events per day
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