3,427 research outputs found
Operation and Utilisation of the High Flux Reactor
The High Flux Reactor (HFR) at Petten is managed by the Institute for Energy (IE) of the EC - DG JRC and operated by NRG who are also licence holder and responsible for commercial activities.
The HFR operates at 45 MW and is of the tank-in-pool type, light water cooled and moderated. It is one of the most powerful multi-purpose materials testing reactors in the world and one of the world leaders in target irradiation for the production of medical radioisotopes.JRC.F.3-Energy securit
Operation and Utilisation of the High Flux Reactor - Annual Report 2006
The High Flux Reactor (HFR) of Petten is owned by the Institute for Energy (IE) of the EC-DG JRC and managed and operated by NRG who are also responsible for commercial activities. The HFR, operated at 45 MW of the tank-in-pool type, light water cooled and moderated, is one of the most powerful multi-purpose materials testing reactors in the world and one of the world leaders in target irradiation for the production of medical radioisotopes.JRC.F.3-High Flux and Future Reactor
Comparison of Muscle Activity Between the Tsunami Barbell\u3csup\u3eTM\u3c/sup\u3e and an Olympic Barbell
Magnetic fields in barred galaxies. IV. NGC 1097 and NGC 1365
We present 3.5cm and 6.2cm radio continuum maps in total and polarized
intensity of the barred galaxies NGC 1097 and NGC 1365. Both galaxies exhibit
radio ridges roughly overlapping with the massive dust lanes in the bar region.
The contrast in total intensity across the radio ridges is compatible with
compression and shear of an isotropic random magnetic field. The contrast in
polarized intensity is significantly smaller than that expected from
compression and shearing of the regular magnetic field; this could be the
result of decoupling of the regular field from the dense molecular clouds. The
regular field in the ridge is probably strong enough to reduce significantly
shear in the diffuse gas (to which it is coupled) and hence to reduce magnetic
field amplification by shearing. This contributes to the misalignment of the
observed field orientation with respect to the velocity vectors of the dense
gas. Our observations, for the first time, indicate that magnetic forces can
control the flow of the diffuse interstellar gas at kiloparsec scales. The
total radio intensity reaches its maximum in the circumnuclear starburst
regions, where the equipartition field strength is about 60\mu G, amongst the
strongest fields detected in spiral galaxies so far. The regular field in the
inner region has a spiral shape with large pitch angle, indicating the action
of a dynamo. Magnetic stress leads to mass inflow towards the centre,
sufficient to feed the active nucleus in NGC 1097. We detected diffuse X-ray
emission, possibly forming a halo of hot gas around NGC 1097.Comment: 32 pages with 45 PostScript figures. Accepted for publication in A&A;
Typos corrected 12/10/200
Critical Metals in Strategic Energy Technologies - Assessing Rare Metals as Supply-Chain Bottlenecks in Low-Carbon Energy Technologies
Due to the rapid growth in demand for certain materials, compounded by political risks associated with the geographical concentration of the supply of them, a shortage of these materials could be a potential bottleneck to the deployment of low-carbon energy technologies. In order to assess whether such shortages could jeopardise the objectives of the EU’s Strategic Energy Technology Plan (SET-Plan), an improved understanding of these risks is vital. In particular, this report examines the use of metals in the six low-carbon energy technologies of SET-Plan, namely: nuclear, solar, wind, bioenergy, carbon capture and storage (CCS) and electricity grids. The study looks at the average annual demand for each metal for the deployment of the technologies in Europe between 2020 and 2030. The demand of each metal is compared to the respective global production volume in 2010. This ratio (expressed as a percentage) allows comparing the relative stress that the deployment of the six technologies in Europe is expected to create on the global supplies for these different metals. The study identifies 14 metals for which the deployment of the six technologies will require 1% or more (and in some cases, much more) of current world supply per annum between 2020 and 2030. These 14 significant metals, in order of decreasing demand, are tellurium, indium, tin, hafnium, silver, dysprosium, gallium, neodymium, cadmium, nickel, molybdenum, vanadium, niobium and selenium. The metals are examined further in terms of the risks of meeting the anticipated demand by analysing in detail the likelihood of rapid future global demand growth, limitations to expanding supply in the short to medium term, and the concentration of supply and political risks associated with key suppliers. The report pinpoints 5 of the 14 metals to be at high risk, namely: the rare earth metals neodymium and dysprosium, and the by-products (from base metals) indium, tellurium and gallium. The report explores a set of potential mitigation strategies, ranging from expanding European output, increasing recycling and reuse to reducing waste and finding substitutes for these metals in their main applications. A number of recommendations are provided which include:
• ensuring that materials used in significant quantities are included in the Raw Materials Yearbook proposed by the Raw Materials Initiative ad hoc Working Group,
• the publication of regular studies on supply and demand for critical metals,
• efforts to ensure reliable supply of ore concentrates at competitive prices,
• promoting R&D and demonstration projects on new lower cost separation processes, particularly those from by-product or tailings containing rare earths,
• collaborating with other countries/regions with a shared agenda of risk reduction,
• raising awareness and engaging in an active dialogue with zinc, copper and aluminium refiners over by-product recovery,
• creating incentives to encourage by-product recovery in zinc, copper and aluminium refining in Europe,
• promoting the further development of recycling technologies and increasing end-of-life collection,
• measures for the implementation of the revised WEEE Directive, and
• investing broadly in alternative technologies.
It is also recommended that a similar study should be carried out to identify the metal requirements and associated bottlenecks in other green technologies, such as electric vehicles, low-carbon lighting, electricity storage and fuel cells and hydrogen.JRC.F.7-Energy systems evaluatio
Top of the class report on the inquiry into teacher education, University of Melbourne Faculty of Education submission.
Critical Metals in the Path towards the Decarbonisation of the EU Energy Sector: Assessing Rare Metals as Supply-Chain Bottlenecks in Low-Carbon Energy Technologies
In order to tackle climate change, to increase energy supply security and to foster the sustainability and
competitiveness of the European economy, the EU has made the transition to a low-carbon economy a
central policy priority. This report builds on the first study conducted in 2011 (Critical Metals in Strategic
Energy Technologies), where critical metals were identified which could become a bottleneck to the
supply-chain of various low-carbon energy technologies. The first study concentrated on the six SET-Plan
technologies, namely: wind, solar (both PV and CSP), CCS, nuclear fission, bioenergy and the electricity
grid. Fourteen metals were identified to be a cause for concern. After taking into account market and
geopolitical parameters, five metals were labelled ‘critical’, namely: tellurium, indium, gallium, neodymium
and dysprosium. The potential supply chain constraints for these materials were most applicable to
the deployment of wind and solar energy technologies. In the follow-up study reported here, other
energy and low-carbon technologies are investigated that not only play an important role in the EU's path
towards decarbonisation but also may compete for the same metals as identified in the six SET-Plan
technologies. Eleven technologies are analysed including fuel cells, electricity storage, electric vehicles
and lighting. As in the first report, sixty metals, i.e. metallic elements, metallic minerals and metalloids
are considered; only iron, aluminium and radioactive elements were specifically excluded. Graphite was
also included, reflecting its status as a critical raw material. Where possible, the study models the implications
for materials demand as a result of the scenarios described in the EU Energy Roadmap 2050.
Consequently, the results obtained in the first study are updated to reflect the data that has become
available in the roadmap. This second study found that eight metals have a high criticality rating and are
therefore classified as ‘critical’. These are the six rare earth elements (dysprosium, europium, terbium,
yttrium, praseodymium and neodymium), and the two metals gallium and tellurium. Four metals (graphite,
rhenium, indium and platinum) are found to have a medium-to-high rating and are classified as ‘near
critical’, suggesting that the market conditions for these metals should be monitored in case the markets
for these metals deteriorate thereby increasing the risk of supply chain bottlenecks. Metals demand in
the electric vehicle, wind, solar and lighting sectors were identified to be of particular concern. As in the
first report, ways of mitigating the supply-chain risks for the critical metals are considered. These fall into
three categories; increasing primary supply, reuse/recycling and substitution In addition, a number of
topics were identified as possibly meriting further research, but could not be considered within the
immediate scope of this study. These include conducting further studies to look at raw materials requirements
for hybrid and electric vehicles for a wider range of technology uptake and penetration
scenarios; developing new and more detailed scenarios for the uptake and technology mix of options for
stationary energy storage; undertaking similar studies in defence and aerospace; improving statistics on
the contribution of recycling to world production for a number of metals; and investigating the contribution
of greater traceability and transparency to reducing raw materials supply risk. Finally, it is important
not to overstate the bottlenecks due to the risks of raw material shortages for key decarbonisation
technologies. This is because there are still many years before the large uptake of some technologies and
in the coming years, there are numerous options that will become available to mitigate the risks identified.JRC.F.6-Energy systems evaluatio
Avaliar a validade da avaliação das carteiras de acreditação
This study examines one part of a validity argument for portfolio assessments of teaching practice used as an indicator of teaching quality to inform a licensure decision. We investigate the relationship among portfolio assessment scores, a test of teacher knowledge (ETS’s Praxis I and II), and changes in student achievement (on Touchstone’s Degrees of Reading Power Test [DRP]). Key questions are the extent to which the assessment of teaching practice (a) predict gains in students’ achievement and (b) contribute unique information to this prediction beyond what is contributed by the tests of teacher knowledge. The venue for our study is Connecticut State Department of Education’s (CSDE) support and licensure system for beginning teachers, the Beginning Educator Support and Training (BEST) program (as it was implemented at the time of our study). We investigated whether elementary teachers’ mean effects on their students’ reading achievement support the use of BEST elementary literacy portfolio scores as a measure of teaching quality for licensure, using a data set gathered from both State and two urban school district sources. The HLM findings indicate that BEST portfolio scores do indeed distinguish among teachers who were more and less successful in enhancing their students’ achievement. An additional analysis indicated that the BEST portfolios add information that is not contained in the Praxis tests, and are more powerful predictors of teachers’ contributions to student achievement gains.Este estudio examina una parte de un argumento de validez para las evaluaciones de los cartera de la práctica docente utilizados como un indicador de la calidad docente para informar una decisión licencia. Investigamos la relación entre los resultados de la evaluación de cartera , una prueba de conocimientos del profesorado ( Praxis I del ETS y II), y los cambios en los logros del estudiante ( en grados de piedra de toque de la prueba eléctrica de la lectura [ DRP ] ) . Las cuestiones clave son la medida en que la evaluación de la práctica docente ( a) predecir las ganancias en el rendimiento de los estudiantes y ( b ) contribuir información única a esta predicción más allá de lo aportado por las pruebas de conocimiento de los maestros . El lugar elegido para nuestro estudio es el Departamento de apoyo y otorgamiento de licencias ( CSDE ) Sistema de Educación para los maestros principiantes del Estado de Connecticut , el Principio Educador , y la programa (BEST ) (como se implementó en el momento de nuestro estudio ) Adiestramiento. Hemos investigado si los "efectos medias en sus alumnos los profesores elementales logros en lectura apoyan el uso de las mejores puntuaciones de la cartera de alfabetización primaria como una medida de calidad de la enseñanza para obtener la licencia , el uso de un conjunto de datos recogidos de Estado y de dos fuentes distrito escolar urbano . Los hallazgos indican que las puntuaciones HLM mejor cartera de hecho distinguen entre los profesores que se encontraban cada vez menos éxito en la mejora de los logros de sus alumnos. Un análisis adicional indicó que los mejores carteras añadir información que no está contenida en las pruebas Praxis , y son más potentes predictores de las contribuciones de los profesores a las ganancias de rendimiento de los estudiantes .O presente estudo analisa uma parte de um argumento de validade para avaliação da carteira de prática de ensino utilizadas como um indicador da qualidade do ensino para informar a decisão de licença. Nós investigamos a relação entre os resultados do portfólio de avaliação, um teste de conhecimentos e competências ( ETS Praxis I e II) , e as mudanças no desempenho do aluno (em graus pedra de toque de teste elétrico leitura [ DRP ] ) . As questões-chave são a medida em que a avaliação da prática docente ( a) prever ganhos no desempenho dos alunos e ( b) contribuir com informações exclusivas para a predição além da evidência fornecida pelo conhecimento dos professores. O local escolhido para o nosso estudo é o suporte Departamento e licenciamento ( CSDE ) Sistema de Educação para professores iniciantes do Estado de Connecticut, o Educador Começando , eo programa (BEST ) (como implementado no momento do nosso estudo ) Treinamento. Nós investigamos se os "efeitos médios em seus professores elementares de leitura os alunos realização apoiar o uso das melhores pontuações da carteira de alfabetização primária como uma medida da qualidade da educação para o licenciamento , o uso de um conjunto de dados coletados fontes do Estado e dois distrito escolar urbano . os resultados indicam que as pontuações melhor portfolio HLM realmente distinguir entre os professores que estavam menos bem sucedido de sempre na melhoria da realização dos seus alunos. Uma análise indicou ainda que os melhores portfolios adicionar informações não contidas nos testes Praxis , e são preditores mais poderosos de contribuições dos professores para os ganhos de desempenho dos alunos
Standard Penetration Test-Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential
This paper presents new correlations for assessment of the likelihood of initiation (or “triggering”) of soil liquefaction. These new correlations eliminate several sources of bias intrinsic to previous, similar correlations, and provide greatly reduced overall uncertainty and variance. Key elements in the development of these new correlations are (1) accumulation of a significantly expanded database of field performance case histories; (2) use of improved knowledge and understanding of factors affecting interpretation of standard penetration test data; (3) incorporation of improved understanding of factors affecting site-specific earthquake ground motions (including directivity effects, site-specific response, etc.); (4) use of improved methods for assessment of in situ cyclic shear stress ratio; (5) screening of field data case histories on a quality/uncertainty basis; and (6) use of high-order probabilistic tools (Bayesian updating). The resulting relationships not only provide greatly reduced uncertainty, they also help to resolve a number of corollary issues that have long been difficult and controversial including: (1) magnitude-correlated duration weighting factors, (2) adjustments for fines content, and (3) corrections for overburden stress
Interrogating the Generalizability of Portfolio Assessments of Beginning Teachers: A Qualitative Study
This qualitative study is intended to illuminate factors that affect the generalizability of portfolio assessments of beginning teachers. By generalizability, we refer here to the extent to which the portfolio assessment supports generalizations from the particular evidence reflected in the portfolio to the conception of competent teaching reflected in the standards on which the assessment is based. Or, more practically, “The key question is, ‘How likely is it that this finding would be reversed or substantially altered if a second, independent assessment of the same kind were made?’” (Cronbach, Linn, Brennan, and Haertel, 1997, p. 1). In addressing this question, we draw on two kinds of evidence that are rarely available: comparisons of two different portfolios completed by the same teacher in the same year and comparisons between a portfolio and a multi-day case study (observation and interview completed shortly after portfolio submission) intended to parallel the evidence called for in the portfolio assessment. Our formative goal is to illuminate issues that assessment developers and users can take into account in designing assessment systems and appropriately limiting score interpretations
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