9 research outputs found

    Improving the collaboration between architects and energy consultants through design-integrated early BIM-tools

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    There is a lack of optimization of buildings towards energy performance in early design stages in practice. Interviews with architects and energy consultants showed that one reason is the inefficient communication between these two groups. This paper investigates how a design-integrated early-BIM tool can improve the relation between architects and energy consultants to support an optimization process in early design stages and facilitate issuing energy performance certificates. Two case studies show that the early-BIM tool provides meaningful results for the architects involved and can reduce the input time for energy consultants by 50%. Furthermore, the simple 3D model functions as boundary object between the two groups and supports the collaboration

    A set of essential requirements towards standardising the numerical simulation of blast-loaded windows and facades

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    The determination of the blast protection level of laminated glass windows and facades is of crucial importance, and it is normally done by using experimental investigations. In recent years numerical methods have become much more powerful also with respect to this kind of application. This report attempts to give a first idea of a possible standardisation concerning such numerical simulations. Attention is drawn to the representation of the blast loading and of the behaviour of the material of the mentioned products, to the geometrical meshing, as well as to the modelling of the connections of the glass components to the main structure. The need to validate the numerical models against reliable experimental data, some of which are indicated, is underlined

    Recommendations for the improvement of existing European norms for testing the resistance of windows and glazed fa\ue7ades to explosive effects

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    It is important to protect critical buildings (shopping centres, government buildings and embassies), infrastructure and utilities, train and underground stations from being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should enhance the resilience of buildings and infrastructures against explosion incidents. In order to protect the built infrastructure, testing methods are required which can answer the question whether certain building elements can withstand certain loading conditions created by an explosive event. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise together, to make it commonly available and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. The TG described in a fist report [JPC87202] the physical phenomena which have to be understood in order to ensure a proper testing of the elements and a correct interpretation of the results. In a second step, the differences between the existing standards for testing blast-resistant glazing and windows have been derived, and a basis for fundamental recommendations for the future development of the suite of European standards has been addressed [JRC94930]. Based on the prior findings, this report now formulates the proper enhancements of the existing standards in terms of actual recommendations for the improvement of the test standards

    Suggestions for adaptations of existing European norms for testing the resistance of windows and glazed fa\ue7ades to explosive effects

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    It is important to protect critical infrastructure buildings, such as shopping centres, government buildings and embassies as well as structures of traffic infrastructure (networks and utilities) from being damaged, destroyed or disrupted by deliberate acts of terrorism, criminal activity and malicious behaviour. Normal regulations and building guidelines do not generally take into account these unexpected threats. The introduction of appropriate regulations or guidelines, where deemed necessary, should enhance the resilience of buildings and infrastructures against explosion incidents. In order to protect the built infrastructure, testing methods are required which can answer the question as to whether specific building elements can withstand extraordinary high loading conditions created by an explosive event. The applicable state-of-the-art techniques may include either experimental or numerical methods, or a combination of both. Therefore, the thematic group (TG) on the resistance of structures to explosion effects was formed in order to bring the required expertise, to make it accessible and to find and define harmonised methods and solutions which can be provided to the decision-makers responsible for critical infrastructure protection. The TG described in a first report [JRC87202] the physical phenomena which have to be understood in order to ensure proper testing of the building elements and correct interpretation of the results. In a second step, the differences between the existing standards for testing blast-resistant glazing and windows have been derived, and a basis for fundamental recommendations for the future development of the suite of European Standards has been addressed [JRC94930]. It describes recommendations for improvements of the current test standards. The report at hand takes the findings of the report [JRC94930] into account. It formulates suggestions for the implementation of improvements of existing testing standards for the evaluation of explosive resistance of security glazing products. New and adapted text passages are provided as suggestions for improvements. Thereby the structure and the format of the existing testing standards EN13123-1 and EN13124-1 were taken as the basis. Thus, the original formulations and the suggestions for adaptations are provided in one document. This document presents only the suggestions for the modifications of the shock tube testing procedure. The recommended modifications to the existing standards EN13123-2 and EN13124-2 for arena testing based on the findings of [JRC94930] will be presented in another document

    RadioAstron gravitational redshift experiment: Status update

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    A test of a cornerstone of general relativity, the gravitational redshift effect, is currently being conducted with the RadioAstron spacecraft, which is on a highly eccentric orbit around Earth. Using ground radio telescopes to record the spacecraft signal, synchronized to its ultra-stable on-board H-maser, we can probe the varying flow of time on board with unprecedented accuracy. The observations performed so far, currently being analyzed, have already allowed us to measure the effect with a relative accuracy of 4 7 10−4. We expect to reach 2.5 7 10−5 with additional observations in 2016, an improvement of almost a magnitude over the 40-year old result of the GP-A mission

    Geodetic data analysis of VGOS experiments

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    Very Long Baseline Interferometry (VLBI) serves as one of the common geodetic methods to define the global reference frames and monitor Earth\u27s orientation variations. The technical upgrade of the VLBI method known as the VLBI Global Observing System (VGOS) includes a critical re-design of the observed frequencies from the dual band mode (S and X band, i.e. 2 GHz and 8 GHz) to observations in a broadband (2-14 GHz). Since 2019 the first VGOS experiments are available for the geodetic analysis in free access at the International VLBI service for Geodesy and Astrometry (IVS). Also regional-only subnetworks such as European VLBI stations have succeeded already in VGOS mode. Based on these brand-new observations we review the current geodetic data analysis workflow to build a bridge between geodetic observed delays derived from different bands

    Mutation in the mouse histone gene <em>Hist2h3c1</em> leads to degeneration of the lens vesicle and severe microphthalmia.

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    During an ENU (N-ethyl-N-nitrosourea) mutagenesis screen, we observed a dominant small-eye mutant mouse with viable homozygotes. A corresponding mutant line was established and referred to as Aey69 (abnormality of the eye #69). Comprehensive phenotyping of the homozygous Aey69 mutants in the German Mouse Clinic revealed only a subset of statistically significant alterations between wild types and homozygous mutants. The mutation causes microphthalmia without a lens but with retinal hyperproliferation. Linkage was demonstrated to mouse chromosome 3 between the markers D3Mit188 and D3Mit11. Sequencing revealed a 358 A- &gt; C mutation (I1e120Leu) in the Hist2h3c1 gene and a 71 T- &gt; C (Val24Ala) mutation in the Gja8 gene. Detailed analysis of eye development in the homozygous mutant mice documented a perturbed lens development starting -from the lens vesicle stage including decreasing expression of crystallins as well as of lens-specific transcription - factors like PITX3 and FOXE3. In contrast, we observed an early expression of retinal progenitor cells characterized by several markers including BRN3 (retinal ganglion cells) and OTX2 (cone photoreceptors). The changes in the retina at the early embryonic stages of E11.5-E15.5 happen in parallel with apoptotic processes in the lens at the respective stages. The excessive retinal hyperproliferation is characterized by an increased level of Ki67. The hyperproliferation, however, does not disrupt the differentiation and appearance of the principal retinal cell types at postnatal stages, even if the overgrowing retina covers finally the entire bulbus of the eye. Morpholino-mediated knock-down of the hist2h3ca1 gene in zebrafish leads to a specific perturbation of lens development. When injected into zebrafish zygotes, only the mutant mouse mRNA leads to severe malformations, ranging from cyclopia to severe microphthalmia. The wild-type Hist2h3c1 mRNA can rescue the morpholino-induced defects corroborating its specific function in lens development. Based upon these data, it is concluded that the ocular function of the Hist2h3c1 gene (encoding a canonical H3.2 variant) is conserved throughout evolution. Moreover, the data highlight also the importance of Hist2h3c1 in the coordinated formation of lens and retina during eye development

    Risk for Major Bleeding in Patients Receiving Ticagrelor Compared With Aspirin After Transient Ischemic Attack or Acute Ischemic Stroke in the SOCRATES Study (Acute Stroke or Transient Ischemic Attack Treated With Aspirin or Ticagrelor and Patient Outcomes)

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    Second asymptomatic carotid surgery trial (ACST-2) : a randomised comparison of carotid artery stenting versus carotid endarterectomy

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    Background: Among asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence. Methods: ACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362. Findings: Between Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86-1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91-1·32; p=0·21). Interpretation: Serious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable
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