Space environmental effects on LDEF composites: A leading edge coated graphite epoxy panel

The electronics module cover for the leading edge (Row D 9) experiment M0003-8 was fabricated from T300 graphite/934 epoxy unidirectional prepreg tape in a (O(sub 2), +/- 45, O(sub 2), +/- 45, 90, 0)(sub s) layup. This 11.75 in x 16.75 in panel was covered with thermal control coatings in three of the four quadrants with the fourth quadrant uncoated. The composite panel experienced different thermal cycling extremes in each quadrant due to the different optical properties of the coatings and bare composite. The panel also experienced ultraviolet (UV) and atomic oxygen (AO) attack as well as micrometeoroid and space debris impacts. An AO reactivity of 0.99 x 10(exp -24) cm(sup 3)/atom was calculated for the bare composite based on thickness loss. The white urethane thermal control coatings (A276 and BMS 1060) prevented AO attack of the composite substrate. However, the black urethane thermal control coating (Z306) was severely eroded by AO, allowing some AO attack of the composite substrate. An interesting banding pattern on the AO eroded bare composite surface was investigated and found to match the dimensions of the graphite fiber tow widths as prepregged. Also, erosion depths were greater in the darker bands. Five micrometeoroid/space debris impacts were cross sectioned to investigate possible structural damage as well as impact/AO interactions. Local crushing and delaminations were found to some extent in all of the impacts. No signs of coating undercutting were observed despite the extensive AO erosion patterns seen in the exposed composite material at the impact sites. An extensive microcrack study was performed on the panel along with modeling of the thermal environment to estimate temperature extremes and thermal shock. The white coated composite substrate displayed almost no microcracking while the black coated and bare composite showed extensive microcracking. Significant AO erosion was seen in many of the cracks in the bare composite

Low-Earth orbit effects on organic composite materials flown on LDEF

Over 35 different types of organic matrix composites were flown as part of 11 different experiments onboard the NASA Long Duration Exposure Facility (LDEF) satellite. This materials and systems experiment satellite flew in low-earth orbit (LEO) for 69 months. For that period, the experiments were subjected to the LEO environment including atomic oxygen (AO), ultraviolet (UV) radiation, thermal cycling, microvacuum, meteoroid and space debris (M&D), and particle radiation. Since retrieval of the satellite in January of 1990, the principal experiment investigators have been deintegrating, examining, and testing the materials specimens flown. The most detrimental environmental effect on all organic matrix composites was material loss due to AO erosion. AO erosion of uncoated organic matrix composites (OMC) facing the satellite ram direction was responsible for significant mechanical property degradations. Also, thermal cycling-induced microcracking was observed in some nonunidirectional reinforced OMC's. Thermal cycling and outgassing caused significant but predictable dimensional changes as measured in situ on one experiment. Some metal and metal oxide-based coatings were found to be very effective at preventing AO erosion of OMC's. However, M&D impacts and coating fractures which compromised these coatings allowed AO erosion of the underlying OMC substrates. The findings for organic matrix composites flown on the LDEF are summarized and the LEO environmental factors, their effects, and the influence on space hardware design factors for LEO applications are identified

Composite materials flown on the Long Duration Exposure Facility

Organic composite test specimens were flown on several LDEF experiments. Both bare and coated composites were flown. Atomic oxygen eroded bare composite material, with the resins being recessed at a greater rate than the fibers. Selected coating techniques protected the composite substrate in each case. Tensile and optical properties are reported for numerous specimens. Fiberglass and metal matrix composites were also flown

The application of systems approach for road safety policy making, Deliverable 8.1 of the H2020 project SafetyCube

The present Deliverable (D8.1) describes the co-ordination of the analysis of risks and measures using a systems framework within the SafetyCube project. It outlines the results of Task 8.1 of Work Package (WP) 8 of SafetyCube. This has involved (i) defining the systems approach to be used within SafetyCube, (ii) developing a taxonomy of risks and measures, (iii) identifying a common set of accident scenarios and (iv) initiating work on the Decision Support System (DSS) development. WP8 of the SafetyCube project has a number of specific aims, including developing the European DSS for supporting evidence-based policy making. It also aims to co-ordinate analysis undertaken in other WPs ensuring integrated research outputs, compilation of the project outputs into a suitable form to be incorporated within the DSS and the European Road Safety Observatory, and finally to develop tools to enable the continued support of evidence based road safety policies beyond SafetyCube. Evidence-based policy making enables policy makers to make justified decisions in the complex reality of road safety interventions. It refers to the use of objective, scientifically-based evidence in all stages of the policy making process. Two important pillars for evidence-based road safety policy making are road safety data and statistics and scientific knowledge (Wegman et al, 2015). This type of policy making can be beneficial (e.g. helps to identify road safety problems and select most appropriate interventions) but also has it’s challenges (e.g. a lot of information at varying levels of detail is required to inform decisions). The DSS that is being developed within SafetyCube aims to support decision makers as well as other stakeholders in their evidence-based policy making. In addition to evidence-based policy making, SafetyCube and in particular the DSS is grounded in the systems approach. The systems approach aims to steer away from the more traditionally ‘human error’ blame focussed approach to road safety, and instead takes into account all ‘components’ in a system (i.e. road users, vehicles, roads) which contribute to a risk of an accident occurring. In SafetyCube, the systems approach is being integrated in the DSS in two main ways. First, the risk factors which relate to the road user, the road or the vehicle will be linked to measures in any or all of these areas if appropriate. Second, to clarify the added value of complementary measures rather than measures in isolation, where appropriate, a description of a measure will pay special attention to and link to supporting measures. The SafetyCube DSS is underpinned by four taxonomies; Road User Behaviour (WP4), Infrastructure (WP5), Vehicles (WP6) and Post Impact Care (WP7). The taxonomy is a main structural part of the DSS system, it can be used as a search option in the DSS, it creates a uniform structure over all work packages and it can be used as a basis for linking risk factors with their corresponding measures. The structure consists of three levels, which are topic, subtopic and specific topic. Thirteen main topics were identified for Road User Behaviour (WP4), 10 main topics for Infrastructure (WP5) and six main topics for Vehicle (WP6). Four topics (based on the DaCoTA webtext on Post Impact Care, 2012), were included in WP7 (Post Impact Care). As expected, there was found to be some overlap between risk factors in one taxonomy and risk factors in another (e.g. is poor vehicle maintenance a Vehicle or Road User-related risk factor?), and some overlaps where a topic could be a risk factor or a countermeasure. Discussions between WPs ensured decisions could be made about how to overcome these ambiguities. Accident scenarios are used within SafetyCube. These are considered to be a classification system for crashes whereby crash types may be grouped according to similar characteristics under a particular scenario heading, creating specific clusters. In total, nine high level accident scenarios will form an entry point to the DSS. Each high level has multiple sub-levels which provide more detailed information about the conflict situation (before the crash). A total of 63 sub-level scenarios are considered. The task of linking risks and measures is currently underway within the SafetyCube project. The accident scenarios will provide a useful and systematic way by which to link risks and measures. They will be used, in order to generate a meaningful set of links, between risks related to specific situations, and measures to address them. The primary objective of the DSS is to provide the European and Global road safety community a user friendly, web-based, interactive Decision Support Tool which will enable policy-makers and stakeholders to select and implement the most appropriate strategies, measures and cost-effective approaches to reduce casualties and crash severity for all road users. It consists of information such as risk factors, road safety measures, cost-benefit, casualty reduction effectiveness estimates. In order to develop the DSS, a review of current existing Decision Support Systems was carried out to provide a first insight into such tools (e.g. Crash Modification Factors Clearinghouse, PRACT Repository, Road Safety Engineering Kit, iRAP). No European DSS were found in the search and of the DSS reviewed, the majority focussed on infrastructure and no risk factors were included. The SafetyCube DSS addresses these gaps. To understand user needs better, three stakeholders workshops were carried out, which allowed participants to comment on the proposed DSS and suggest ‘hot topics’ (i.e. important risk factors) to address in SafetyCube, and the findings of these workshops found that the DSS should be suitable for use by a wide range of users, should be impartial, include robust data and access to all studies used and generated results. A comprehensive common SafetyCube methodology was designed, which included: a complete taxonomy of human behaviour, infrastructure and vehicle; a detailed and recorded literature review and the development of a template for coding research studies and existing results to be stored in a database linked to the DSS. The DSS is being created on the basis of a number of design principles (e.g. modern web-based tool, ergonomic interface, simple, easily updated…). As well as a consistent layout the content itself is also of high importance (e.g. quantitative results over qualitative, methodologically sound, clarity). The DSS itself consists of the backend (relational database), the front end (website) and the way they integrate (queries). The heart of the DSS consists of the searchable/dynamic and static aspects, which consists of five entry points and three levels. The design principles of the DSS ensure a smooth integration of the Work Packages in two ways, firstly that the SafetyCube common methodology is applied and secondly that the fully linked search allows the end user to better perceive the interactions between various components in road safety. There are five entry points into DSS: ‘text search’, ‘risk factors’, ‘road safety measures’, ‘road user groups’ and ‘accident scenarios’. Once a search has been undertaken using one of these five entry points, a results page is shown to the user, which consists of a table listing the available synopses1 (overview of the topic created by synthesising findings from the coding of existing studies), meta-analysis and other studies in the database. From this, the user can then also access the individual study pages for each study listed in the results. Finally, a Tools page allows the user to access other SafetyCube tools (e.g. cost-benefit calculator, methodology information, glossary). 1 More details about the synopses can be found in the Milestone M3.1 (Martensen 2016). So far, more than 500 studies have been analysed in the area of road risks with more than 3,500 risk estimates, summarised in more than 60 synopses (including approximately 10 meta-analyses), and the related measures analyses are in progress. This wealth of information will all be incorporated into the DSS and become its core outputs. The overall design of the DSS is finalised and is currently available, with the next stage being the DSS development, including all risk factors and measures. The DSS Pilot Operation will occur later in the project, followed by the final opening of the DSS, with continual updates from the end of the project onwards. The SafetyCube DSS is intended to have a life well beyond the end of the SafetyCube research project

Genetic characterization of the HrpL regulon of the fire blight pathogen Erwinia amylovora reveals novel virulence factors

The bacterial pathogen Erwinia amylovora is the causal agent of fire blight, an economically significant disease of apple and pear. Disease initiation by E. amylovora requires the translocation of effector proteins into host cells via the hypersensitive response and pathogenicity (hrp) type III secretion system (T3SS). The alternative sigma factor HrpL positively regulates the transcription of structural and translocated components of the T3SS via hrp promoter elements. To characterize genome-wide HrpL-dependent gene expression in E. amylovora Ea1189, wild-type and Ea1189ΔhrpL strains were cultured in hrp-inducing minimal medium, and total RNA was compared using a custom microarray designed to represent the annotated genes of E. amylovora ATCC 49946. The results revealed 24 genes differentially regulated in Ea1189ΔhrpL relative to Ea1189 with fold-change expression ratios greater than 1.5; of these, 19 genes exhibited decreased transcript abundance and five genes showed increased transcript abundance relative to Ea1189. To expand our understanding of the HrpL regulon and to elucidate direct versus indirect HrpL-mediated effects on gene expression, the genome of E. amylovora ATCC 49946 was examined insilico using a hidden Markov model assembled from known Erwinia spp. hrp promoters. This technique identified 15 putative type III novel hrp promoters, seven of which were validated with quantitative polymerase chain reaction based on expression analyses. It was found that HrpL-regulated genes encode all known components of the hrp T3SS, as well as five putative type III effectors. Eight genes displayed apparent indirect HrpL regulation, suggesting that the HrpL regulon is connected to downstream signalling networks. The construction of deletion mutants of three novel HrpL-regulated genes resulted in the identification of additional virulence factors as well as mutants displaying abnormal motility and biofilm phenotypes

SafetyCube: Building a decision support system on risks and measures

The EU research project SafetyCube (Safety CaUsation, Benefits and Efficiency) is developing an innovative road safety Decision Support System (DSS) collecting the available evidence on a broad range of road risks and possible countermeasures. The structure underlying the DSS consists of (1) a taxonomy identifying risk factors and measures and linking them to each other, (2) a repository of studies, and (3) synopses summarizing the effects estimated in the literature for each risk factor and measure, and (4) an economic efficiency evaluation (E3-calculator). The DSS is implemented in a modern web-based tool with a highly ergonomic interface, allowing users to get a quick overview or go deeper into the results of single studies according to their own needs

The European road safety decision support system on risks and measures

The European Road Safety Decision Support System (roadsafety-dss.eu) is an innovative system providing the available evidence on a broad range of road risks and possible countermeasures. This paper describes the scientific basis of the DSS. The structure underlying the DSS consists of (1) a taxonomy identifying risk factors and measures and linking them to each other, (2) a repository of studies, and (3) synopses summarizing the effects estimated in the literature for each risk factor and measure, and (4) an economic efficiency evaluation instrument (E3-calculator). The DSS is implemented in a modern web-based tool with a highly ergonomic interface, allowing users to get a quick overview or go deeper into the results of single studies according to their own needs

Assembly of Annual Statistical Report and Basic Fact Sheets - 2012

La base de datos CARE reúne los datos desagregados de los accidentes de tránsito y las víctimas de toda Europa , al combinar las bases de datos nacionales sobre accidentes que son mantenidos por todos los estados miembros de la UE . El acceso a la base de datos CARE se limita , sin embargo , por lo que es importante que una amplia gama de publicaciones sobre la base de estos datos sea accesible al público en general . Este proceso se inició en el proyecto SafetyNet que se llevó a cabo entre 2004 y 2008 , y el concepto de la Hoja de Datos Básicos ( BFS ) Hojas de datos básicos y el Informe Anual ( ASR ) se ha desarrollado. En 2008, doce hojas informativas se están preparando anualmente por investigadores de cinco institutos y un informe estadístico . Una de las tareas de Dacota Paquete de Trabajo 3 ha sido la de continuar desarrollando esta área de trabajo . Se han actualizado Estos doce de la BFS y el nuevo contenido se ha añadido . Se han desarrollado de seis nuevos BFS , y se enumeran las de BFS dieciocho a continuación junto con el socio responsable de la preparación de la versión 2012 . Las Hojas Informativas presentan una visión general destacando los principales hechos de un tema específico. Siempre que sea posible , las medidas de riesgo se calculan relacionando el número de víctimas mortales de CARE a los datos de exposición disponibles de otras fuentes. La mayoría de las Hojas Informativas examinaron las tendencias en el período 2001-2010 , con análisis más detallados de los datos de 2010 . Estos socios también trabajaron para elaborar el Informe Estadístico Anual de 2008 , dirigido por KFV . Más recientes datos de accidentes de tráfico de la base de datos CARE, para que más países se incorporaron . El Informe Estadístico Anual consta de un gran número de tablas y figuras con los datos recuperados de la base de datos CARE, sin mayor análisis o comentario . Incluye un glosario con las definiciones de las variables y los valores utilizados en el Informe Estadístico Anual . El Informe Estadístico Anual de 2012 proporciona las características básicas de los accidentes de tráfico en los 26 estados miembros de la Unión Europea y Suiza para el período 2001-2010 , y los datos más detallados para el último año disponible. Se compone de 56 tablas y 26 figuras con la combinación más interesante de los datos de accidentes de tráfico de CARE sobre los principales temas de seguridad vial , dando la descripción general de la situación de la seguridad vial en la UE y el desarrollo de las muertes en los países a través del tiempo . Efectuará un seguimiento de las tendencias utilizando series de tiempo de datos fatales de la década y también analiza los datos sobre muertes y de accidentes fatales para los diferentes atributos relacionados con accidentes como el tiempo , el tipo de zona , la red de carreteras y el modo de transporte.The CARE database brings together the disaggregate details of road accidents and casualties across Europe, by combining the national accident databases that are maintained by all EU member states. Access to the CARE database is restricted, however, so it is important that a comprehensive range of publications based on these data be accessible to the general public. This process was begun in the SafetyNet project that was carried out between 2004 and 2008, and the concept of the Basic Fact Sheet (BFS) Basic Fact Sheets and Annual Statistical Report (ASR) was developed. By 2008, twelve Fact Sheets were being prepared annually by researchers at five institutes and one Statistical Report. One of the tasks of DaCoTA Work Package 3 has been to continue to develop this area of work. These twelve BFS’s have been updated and new content has been added. Six new BFS’s have been developed, and the eighteen BFS’s are listed below together with the partner responsible for the preparation of the 2012 version. The Fact Sheets present an overview highlighting the main facts for a specific topic. Wherever possible, measures of risk are calculated by relating the number of fatalities from CARE to exposure data available from other sources. Most Fact Sheets examined trends over the period 2001-2010, with more detailed analyses of data from 2010. These partners also worked to develop the Annual Statistical Report of 2008, led by KfV. More recent road accident data from the CARE database, for more countries, were incorporated. The Annual Statistical Report consists of a large number of Tables and Figures with data retrieved from the CARE database, without further analysis or comment. It includes a Glossary with the definitions of the variables and values used in the Annual Statistical Report. The Annual Statistical Report of 2012 provides the basic characteristics of road accidents in 26 member states of the European Union and Switzerland for the period 2001-2010, and more detailed data for the last available year. It consists of 56 Tables and 26 Figures with the most interesting combination of CARE road accident data on major road safety topics, giving the overall description of the road safety situation in the EU and the development of fatalities in the countries over time. It monitors trends using time series of fatal data from the decade and also analyses data on fatalities and fatal accidents for different accident-related attributes like time, area type, road network and mode of transport

OpenSAFELY: a platform for analysing electronic health records designed for reproducible research

Electronic health records (EHRs) and other administrative health data are increasingly used in research to generate evidence on the effectiveness, safety, and utilisation of medical products and services, and to inform public health guidance and policy. Reproducibility is a fundamental step for research credibility and promotes trust in evidence generated from EHRs. At present, ensuring research using EHRs is reproducible can be challenging for researchers. Research software platforms can provide technical solutions to enhance the reproducibility of research conducted using EHRs. In response to the COVID-19 pandemic, we developed the secure, transparent, analytic open-source software platform OpenSAFELY designed with reproducible research in mind. OpenSAFELY mitigates common barriers to reproducible research by: standardising key workflows around data preparation; removing barriers to code-sharing in secure analysis environments; enforcing public sharing of programming code and codelists; ensuring the same computational environment is used everywhere; integrating new and existing tools that encourage and enable the use of reproducible working practices; and providing an audit trail for all code that is run against the real data to increase transparency. This paper describes OpenSAFELY’s reproducibility-by-design approach in detail