AVCOAT Density Characterization for Orion Multi-Purpose Crew Vehicle

The Orion Multi-Purpose Crew Vehicle (MPCV) will transport four crew members to and from lunar-class orbital destinations. The first orbital Exploration Flight Test (EFT-1) is scheduled for December 2014 and will provide valuable data on several systems, including the heat shield. The heat shield material is AvcoatTM, a mid-density ablator. Specifically, the heat shield contains a fiberglass-phenolic honeycomb structure filled with an ablative epoxy novolac resin. Post-flight characterization of the EFT-1 thermal protection system will be conducted in order to study the material response and measure the char front of the material. Avcoat density profiling will be conducted to study three critical material zones: char, pyrolysis, and virgin states as a function of material depth. As part of a ground test campaign, Avcoat coupons are tested at the NASA Ames Research Center Arc Jet Complex. The test campaign is set forth to study material response based on environments, perform Avcoat material density characterization, and compare the char depths from the HEAT sensor and density profiling studies. These investigations will then be compared to flight data in order to improve upon TPS material response models

O USO DO VDC SCORECARD NA VALIDAÇÃO DE MÉTODOS PARA ANÁLISE DE DESEMPENHO DA GESTÃO DO PROCESSO DE PROJETO NO CENÁRIO BRASILEIRO

The implementation of information technologies for civil construction such asVirtual Design and Construction/Building Information Modeling (VDC/BIM) represents a newperspective on better practices in the Architecture, Engineering, Construction, and, Operation(AECO). However, in the Brazilian scene, these practices are need methods for measuringand process performance analysis of the information in the design process management,demonstrating the lack of criteria documentation and indicators selection that contribute tothe improvement in the civil construction sector. It is a descriptive research exploring theVDC Scorecard method and its application to Brazilian reality, based on existing literatureand documentary research in international and national databases, exploring the followingaspects: registered benefits; difficulties for implementation; and good practices in projectmanagement. The research validates the importance of performance methods that areappropriate to a national context, enabling the integration and control of information amongstakeholders in a collaborative virtual building model and the data ownership throughperformance models configured by continuous analysis of the processes, organization andproduct. This comprehension enables the documentation of effective practices in a databasefor the design process management setting the model’s performanceA implementação de tecnologias da informação na construção civil, como Virtual Design and Construction / Building Information Modeling (VDC/BIM) representam uma nova perspectiva para melhores práticas na AECO (Arquitetura; Engenharia; Construção; Operação). Contudo, no cenário brasileiro, estas práticas carecem de métodos para medição e análise de desempenho processual da informação na gestão do processo de projeto, demonstrando a deficiência da documentação de critérios e seleção de indicadores que contribuam para melhoria do setor da construção civil. Trata-se de uma pesquisa descritiva sobre a exploração do método VDC Scorecard e a adaptação à realidade brasileira, tendo por base pesquisa bibliográfica e documental existentes em bases de dados internacionais e nacionais explorando os seguintes aspectos: benefícios registrados; dificuldades na implementação; boas práticas na gestão do projeto. A pesquisa valida a importância dos métodos de desempenho que se adequem ao contexto nacional, viabilizando a integração e controle da informação entre agentes envolvidos num modelo colaborativo de edificação virtual e apropriação de dados por meio dos modelos de desempenho configurados através da análise contínua dos processos, da organização e do produto. Esta apropriação possibilita a documentação de um banco de dados de práticas eficientes para gestão de processos de projeto configurando o desempenho do modelo

Development of a coupled simulation toolkit for computational radiation biology based on Geant4 and CompuCell3D

RL acknowledges support from Consortium for Risk Evaluation and Stakeholder Participation (http://cresp.org). JAG acknowledges support from National Science Foundation grant NSF 1720625 and National Institutes of Health, National Institute of General Medical Sciences grants U01 GM111243 and R01 GM076692, JAG and MS acknowledge support from National Institutes of Health, National Institute of General Medical Sciences grant R01 GM122424.Understanding and designing clinical radiation therapy is one of the most important areas of state-of-the-art oncological treatment regimens. Decades of research have gone into developing sophisticated treatment devices and optimization protocols for schedules and dosages. In this paper, we presented a comprehensive computational platform that facilitates building of the sophisticated multi-cell-based model of how radiation affects the biology of living tissue. We designed and implemented a coupled simulation method, including a radiation transport model, and a cell biology model, to simulate the tumor response after irradiation. The radiation transport simulation was implemented through Geant4 which is an open-source Monte Carlo simulation platform that provides many flexibilities for users, as well as low energy DNA damage simulation physics, Geant4-DNA. The cell biology simulation was implemented using CompuCell3D (CC3D) which is a cell biology simulation platform. In order to couple Geant4 solver with CC3D, we developed a "bridging" module, RADCELL, that extracts tumor cellular geometry of the CC3D simulation (including specification of the individual cells) and ported it to the Geant4 for radiation transport simulation. The cell dose and cell DNA damage distribution in multicellular system were obtained using Geant4. The tumor response was simulated using cell-based tissue models based on CC3D, and the cell dose and cell DNA damage information were fed back through RADCELL to CC3D for updating the cell properties. By merging two powerful and widely used modeling platforms, CC3D and Geant4, we delivered a novel tool that can give us the ability to simulate the dynamics of biological tissue in the presence of ionizing radiation, which provides a framework for quantifying the biological consequences of radiation therapy. In this introductory methods paper, we described our modeling platform in detail and showed how it can be applied to study the application of radiotherapy to a vascularized tumor.PostprintPeer reviewe

Solution structure of the dimerization domain of ribosomal protein P2 provides insights for the structural organization of eukaryotic stalk

The lateral stalk of ribosome is responsible for kingdom-specific binding of translation factors and activation of GTP hydrolysis that drives protein synthesis. In eukaryotes, the stalk is composed of acidic ribosomal proteins P0, P1 and P2 that constitute a pentameric P-complex in 1: 2: 2 ratio. We have determined the solution structure of the N-terminal dimerization domain of human P2 (NTD-P2), which provides insights into the structural organization of the eukaryotic stalk. Our structure revealed that eukaryotic stalk protein P2 forms a symmetric homodimer in solution, and is structurally distinct from the bacterial counterpart L12 homodimer. The two subunits of NTD-P2 form extensive hydrophobic interactions in the dimeric interface that buries 2400 Å2 of solvent accessible surface area. We have showed that P1 can dissociate P2 homodimer spontaneously to form a more stable P1/P2 1 : 1 heterodimer. By homology modelling, we identified three exposed polar residues on helix-3 of P2 are substituted by conserved hydrophobic residues in P1. Confirmed by mutagenesis, we showed that these residues on helix-3 of P1 are not involved in the dimerization of P1/P2, but instead play a vital role in anchoring P1/P2 heterodimer to P0. Based on our results, models of the eukaryotic stalk complex were proposed

Solution structure of the dimerization domain of ribosomal protein P2 provides insights for the structural organization of eukaryotic stalk

The lateral stalk of ribosome is responsible for kingdom-specific binding of translation factors and activation of GTP hydrolysis that drives protein synthesis. In eukaryotes, the stalk is composed of acidic ribosomal proteins P0, P1 and P2 that constitute a pentameric P-complex in 1: 2: 2 ratio. We have determined the solution structure of the N-terminal dimerization domain of human P2 (NTD-P2), which provides insights into the structural organization of the eukaryotic stalk. Our structure revealed that eukaryotic stalk protein P2 forms a symmetric homodimer in solution, and is structurally distinct from the bacterial counterpart L12 homodimer. The two subunits of NTD-P2 form extensive hydrophobic interactions in the dimeric interface that buries 2400 Å2 of solvent accessible surface area. We have showed that P1 can dissociate P2 homodimer spontaneously to form a more stable P1/P2 1 : 1 heterodimer. By homology modelling, we identified three exposed polar residues on helix-3 of P2 are substituted by conserved hydrophobic residues in P1. Confirmed by mutagenesis, we showed that these residues on helix-3 of P1 are not involved in the dimerization of P1/P2, but instead play a vital role in anchoring P1/P2 heterodimer to P0. Based on our results, models of the eukaryotic stalk complex were proposed

Chapter 9 Outdoor air pollutants sources, characteristics, and impact on human health and the environment

In this chapter, sources and characteristics of outdoor air pollutants are presented along with their effects on human health and the environment. In addition, emphasis is given to air pollutant monitoring by exploring the type of monitoring programs, sampling methods, and emission standards and by presenting the case of air pollution monitoring in the United Arab Emirates. Finally, the chapter explores the case of climate change by looking into its causes and economic and environmental impacts