884 resultados para Helmet Standards.
Resumo:
Utilizing the neutron-irradiation parameter J is one of the major uncertainties in 40Ar/39Ar dating. The associated error of the individual J-value for a sample of unknown age depends on the accuracy of the age of the geological standards, the fast-neutron fluence distribution in the reactor and the distances between standards and samples during irradiation. While it is generally assumed that rotating irradiation evens out radial neutron fluence gradients, we observed axial and radial variations of the J-values in sample irradiations in the rotating channels of two reactors. To quantify them, we included three-dimensionally distributed metallic fast- (Ni) and thermal- (Co) neutron fluence monitors in three irradiations and geological age standards in three more. Two irradiations were carried out under Cd-shielding in the FRG1 reactor in Geesthacht, Germany, and four without Cd-shielding in the LVR-15 reactor in Rez, Czech Republic. The 58Ni(nf,p)58Co activation reaction and ?-spectrometry of the 811 keV peak associated with the subsequent decay of 58Co to 58Fe allow to calculate the fast-neutron fluence. The fast-neutron fluences at known positions in the irradiation container correlate with the J-values determined by mass-spectrometric 40Ar/39Ar measurements of the geological age standards. Ra-dial neutron fluence gradients are up to 1.8 %/cm in FRG1 and up to 2.2 %/cm in LVR-15; the corre-sponding axial gradients are up to 5.9 and 2.1 %/cm. We conclude that sample rotation might not al-ways suffice to meet the needs of high-precision dating and gradient monitoring can be crucial.
Resumo:
This paper uses firm-level data to examine the impact of chemical safety regulations imposed by importing countries such as RoHS and REACH on the production costs and export performance of firms in Malaysia and Vietnam. We find that in addition to the initial setup costs for compliance, EU RoHS and REACH implementation causes firms to incur additional variable production costs by requiring additional labor and capital expenditures of around 12% of the variable costs, respectively. We also find that compliance with RoHS and REACH significantly increases the probability of export. Furthermore, we find that compliance with EU RoHS and REACH helps firms to penetrate into a greater variety of countries. Also, we find that multinational enterprises and firms participating in global value chains generally exhibit better export performance and their costs rise less steeply.
Resumo:
Despite the acknowledged need of providing a personalized and adaptive learning process for all, current learning management systems do not properly cover personalization and accessibility issues and they are still struggling to support the reusability requirements coming from the pervasive usage of standards. There is a lack of frameworks for providing layered-based infrastructure covering the interoperability required to manage the whole range of standards, applications and services needed to meet accessibility and adaptations needs of lifelong learning services.
Resumo:
In recent years, a variety of systems have been developed that export the workflows used to analyze data and make them part of published articles. We argue that the workflows that are published in current approaches are dependent on the specific codes used for execution, the specific workflow system used, and the specific workflow catalogs where they are published. In this paper, we describe a new approach that addresses these shortcomings and makes workflows more reusable through: 1) the use of abstract workflows to complement executable workflows to make them reusable when the execution environment is different, 2) the publication of both abstract and executable workflows using standards such as the Open Provenance Model that can be imported by other workflow systems, 3) the publication of workflows as Linked Data that results in open web accessible workflow repositories. We illustrate this approach using a complex workflow that we re-created from an influential publication that describes the generation of 'drugomes'.
Resumo:
The aeronautical information plays an essential rolein air safety, chief objective of the aeronautical industry. Community policies and projects are being currently developed for the adequate management of a single European air space. To make this possible, an appropriate information management and a set of tools that allow sharing and exchanging this information, ensuring its interoperability and integrity, are necessary. This paper presents the development and implementation of a metadata profile for description of the aeronautical information based on international regulations and recommendations applied within the geographic scope. The elements taken into account for its development are described, as well as the implementation process and the results obtained.
Resumo:
Within the European Union, member states are setting up official data catalogues as entry points to access PSI (Public Sector Information). In this context, it is important to describe the metadata of these data portals, i.e., of data catalogs, and allow for interoperability among them. To tackle these issues, the Government Linked Data Working Group developed DCAT (Data Catalog Vocabulary), an RDF vocabulary for describing the metadata of data catalogs. This topic report analyzes the current use of the DCAT vocabulary in several European data catalogs and proposes some recommendations to deal with an inconsistent use of the metadata across countries. The enrichment of such metadata vocabularies with multilingual descriptions, as well as an account for cultural divergences, is seen as a necessary step to guarantee interoperability and ensure wider adoption.
Resumo:
Brick facades are a construction type, strongly linked to local construction characteristics and methods. In Spain, particularly in Castilla, the facades have been built since the '80s with Castilian half foot (11.5 cm), resting on the edge of slabs. The design of these facades, to horizontal loads from wind, depending on the codes used, can lead to completely different valid solutions. Applying same loads, the facades studied with current European standard (Eurocode 6), have a maximum length of 7.1 m between supports, while the Spanish code, Technical Building Code - Structural Safety Masonry, (CTE SE-F), 8.4 m can be achieved. This represents an increase of flexural strength, depending on the calculation model used, which can reach until 8 times. This is due to the difference of the calculation method and the structural model in one and another standard, depending on if this facade is analyzed as a vertical or horizontal beam or by formation of a vertical or horizontal archh. This paper analyzes the constructive solution of the brick facades that results from applying Spanish or European standards and how it affects the model applied in the safety of the resulting facade.
Resumo:
Monte Carlo calculations were carried out to characterize the neutron field produced by the calibration neutron sources of the Neutron Standards Laboratory at the Research Center for Energy, Environment and Technology (CIEMAT) in Spain. For 241AmBe and 252Cf neutron sources, the neutron spectra, the ambient dose equivalent rates and the total neutron fluence rates were estimated. In the calibration hall, there are several items that modify the neutron field. To evaluate their effects different cases were used, from point-like source in vacuum up to the full model. Additionally, using the full model, the neutron spectra were estimated to different distances along the bench; with these spectra, the total neutron fluence and the ambient dose equivalent rates were calculated. The hall walls induce the largest changes in the neutron spectra and the respective integral quantities. The free-field neutron spectrum is modified due the room return effect.
Resumo:
The Connecticut State Medical Society (CSMS) reviews and accredits the continuing medical education (CME) programs offered by Connecticut's hospitals. As part of the survey process, the CSMS assesses the quality of the hospitals' libraries. In 1987, the CSMS adopted the Medical Library Association's (MLA's) “Minimum Standards for Health Sciences Libraries in Hospitals.” In 1990, professional librarians were added to the survey team and, later, to the CSMS CME Committee. Librarians participating in this effort are recruited from the membership of the Connecticut Association of Health Sciences Librarians (CAHSL). The positive results of having a qualified librarian on the survey team and the invaluable impact of adherence to the MLA standards are outlined. As a direct result of this process, hospitals throughout the state have added staffing, increased space, and added funding for resources during an era of cutbacks. Some hospital libraries have been able to maintain a healthy status quo, while others have had proposed cuts reconsidered by administrators for fear of losing valuable CME accreditation status. Creating a relationship with an accrediting agency is one method by which hospital librarians elsewhere may strengthen their efforts to ensure adequate library resources in an era of downsizing. In addition, this collaboration has provided a new and important role for librarians to play on an accreditation team.