956 resultados para Structures in Reinforced Concrete
Resumo:
It has been analyzed samples of portland cement (PC) with and without admixtures, samples of calcium aluminate cement (CAC) with different content of Al2O3 and specimens of concrete made with PC and CAC using High Resolution Gamma Spectrometry. The activity concentration index (I) is much less than 0.5 mSv y-1 for all the concrete specimens according to the Radiation protection document 112 of the European Commission. The PC without admixtures (CEM I 52,5 R) and the PC with addition of limestone (CEM II/BL 32,5 N) also have an I value much lower than 0.5 and the PC with the addition of fly ash and blast furnace slag (CEM IV/B (V) 32,5 N and III/A 42.5 N/SR) have an I value close to 0.6. The I value of the CAC used in the manufacture of structural precast concrete is of the order of 1 mSv y-1. Some of the CAC used in refractory concrete reaches a value close to 2 mSv y-1.
Resumo:
This study is in the frame of the cooperative line that several Spanish Universities and other foreign partners started with the Haitian government in 2010. According to our studies (Benito et al. in An evaluation of seismic hazard in La Hispaniola, after the 2010 Haiti earthquake, 33rd General Assembly of the European Seismological Commission, Moscow, Russia, 2012) and recent scientific literature, the earthquake hazard in Haiti remains high (Calais et al. in Nat Geosci 3:794–799, 2010). In view of this, we wonder whether the country is currently ready to face another earthquake. In this sense, we estimated several damage scenarios in Port-au-Prince and Cap-Haitien associated to realistic possible major earthquakes. Our findings show that almost 50 % of the building stock of both cities would result uninhabitable due to structural damage. Around 80 % of the buildings in both cities have reinforced concrete structure with concrete block infill; however, the presence of masonry buildings becomes significant (between 25 and 45 % of the reinforced concrete buildings) in rural areas and informal settlements on the outskirts, where the estimated damage is higher. The influence of the soil effect on the damage spatial distribution is evident in both cities. We have found that the percentage of uninhabitable buildings in soft soil areas may be double the percentage obtained in nearby districts located in hard soil. These results reveal that a new seismic catastrophe of similar or even greater consequences than the 2010 Haiti earthquake might happen if the earthquake resilience is not improved in the country. Nowadays, the design of prevention actions and mitigation policies is the best instrument the society has to face seismic risk. In this sense, the results of this research might contribute to define measures oriented to earthquake risk reduction in Haiti, which should be a real priority for national and international institutions.
Resumo:
Light confinement and controlling an optical field has numerous applications in the field of telecommunications for optical signals processing. When the wavelength of the electromagnetic field is on the order of the period of a photonic microstructure, the field undergoes reflection, refraction, and coherent scattering. This produces photonic bandgaps, forbidden frequency regions or spectral stop bands where light cannot exist. Dielectric perturbations that break the perfect periodicity of these structures produce what is analogous to an impurity state in the bandgap of a semiconductor. The defect modes that exist at discrete frequencies within the photonic bandgap are spatially localized about the cavity-defects in the photonic crystal. In this thesis the properties of two tight-binding approximations (TBAs) are investigated in one-dimensional and two-dimensional coupled-cavity photonic crystal structures We require an efficient and simple approach that ensures the continuity of the electromagnetic field across dielectric interfaces in complex structures. In this thesis we develop \textrm{E} -- and \textrm{D} --TBAs to calculate the modes in finite 1D and 2D two-defect coupled-cavity photonic crystal structures. In the \textrm{E} -- and \textrm{D} --TBAs we expand the coupled-cavity \overrightarrow{E} --modes in terms of the individual \overrightarrow{E} -- and \overrightarrow{D} --modes, respectively. We investigate the dependence of the defect modes, their frequencies and quality factors on the relative placement of the defects in the photonic crystal structures. We then elucidate the differences between the two TBA formulations, and describe the conditions under which these formulations may be more robust when encountering a dielectric perturbation. Our 1D analysis showed that the 1D modes were sensitive to the structure geometry. The antisymmetric \textrm{D} mode amplitudes show that the \textrm{D} --TBA did not capture the correct (tangential \overrightarrow{E} --field) boundary conditions. However, the \textrm{D} --TBA did not yield significantly poorer results compared to the \textrm{E} --TBA. Our 2D analysis reveals that the \textrm{E} -- and \textrm{D} --TBAs produced nearly identical mode profiles for every structure. Plots of the relative difference between the \textrm{E} and \textrm{D} mode amplitudes show that the \textrm{D} --TBA did capture the correct (normal \overrightarrow{E} --field) boundary conditions. We found that the 2D TBA CC mode calculations were 125-150 times faster than an FDTD calculation for the same two-defect PCS. Notwithstanding this efficiency, the appropriateness of either TBA was found to depend on the geometry of the structure and the mode(s), i.e. whether or not the mode has a large normal or tangential component.
Resumo:
Over the past seventeen years Canada has decentralized many social programmes, moving responsibility from the federal government to 13 provinces and territories through bilateral federal-provincial agreements. In contrast, the European Union (EU) has moved in the opposite direction, building pan-European approaches and establishing new processes to facilitate multilateral collaboration among the 28 EU member states. This has been done through a new governance approach called the Open Method of Coordination (OMC). Using a detailed case study − employment policy − this paper explores whether Canada could learn from OMC governance ideas to re-build a pan-Canadian dimension to employment policy and improve the performance of its intergovernmental relations system. Concrete lessons for Canada to improve decentralized governance are suggested: consolidating the different bilateral agreements; using benchmarking instead of controls in fiscal transfers; undertaking research, analysis, and comparisons in order to facilitate mutual learning; revitalizing intergovernmental structures in light of devolution; and engaging social partners, civil society and other stakeholders. Post-devolution Canada is not doing badly in managing employment policy, but could do better. Looking to the EU for ideas on new ways to collaborate provides a chance for setting a forward looking agenda that could ultimately result not only in better labour market outcomes, but also improvements to one small part of Canada’s often fractious federation.
Resumo:
Israel figures among the world-leaders in R&D expenditure and has a high-performing scientific community. Since the 1990s it has been associated with the Scientific Policy of the European Union via the European Research Framework Programmes (FP). The cooperation between Israel and the EU in this domain has gradually increased and benefits the scientific communities on both sides. In 2014 the association of Israel to the latest and biggest European FP ever adopted (Horizon 2020) was renewed for the fourth time. Based on all the scientific evidence provided, the elaboration of a European Research Policy can be identified as a highly regulated domain, offering relevant ‘channels of influence’. These channels offer Israel the opportunity to act within the Research Policy system. Being a member of several formal EU bodies in charge of implementing EU Research Policy, Israel is able to introduce its positions effectively. This is accompanied by an outstanding level of activity by Israel in linking concrete EU Research Policy measures to the Israeli Scientific Community at the national level. To carry out this task, Israel relies on an effective organization, which remodels the provided EU structures: European ‘National Contact Points’ (NCPs) are concentrated within the ‘Europe Israel R&D Directorate’ (ISERD). ISERD connects efficiently all the relevant actors, forums and phases of EU-Israeli Research Policy. ISERD can be recognized as being at the heart of Israel's research cooperation with the EU, and its structure may be a source of in
Resumo:
"September 1998."
Resumo:
Includes index.
Resumo:
Mode of access: Internet.
Resumo:
Vols. 7-13 have added t.p.: Schlomann-Oldenbourgh illustrierte technische wörterbücher, unter mitwirkung hervorragender fachieute des in- und auslandes, hrsg. von Alfred Schlomann ... Müchen und Berlin, Druck und verlag von R. Oldenbourg; London, Constable & Co., etc.
Resumo:
"Verzeichnis von Abhandlung über Eisenbeton-Balkenbrücken in verschiedenen Fachzeitschriften," vol.1, p.185-187; "Verzeichnis von neueren Abhandlungen über Eisenbeton-Wölbbrücken in verschiedenen Fachzeitschriften," vol.2, p.195-198.
Resumo:
Mode of access: Internet.
Resumo:
Mode of access: Internet.
Resumo:
"March 1998."
Resumo:
"Report no. IL-PRR-140"--Technical report documentation page.
Resumo:
Mode of access: Internet.