588 research outputs found
Electrical pulses protect concrete
No full textEven concrete is not as hard as it looks. Sea water, salt on icy roads, and indirectly even carbon dioxide from the air can corrode the steel of the reinforcing bars and so threaten the strength and integrity of a bridge pier, jetty, or viaduct. Dessi Koleva, a chemical engineer from Bulgaria, spent her doctoral research at the Faculty of Civil Engineering and Geosciences devising a method for the cathodic protection of steel rebars. The method is cheaper and also has fewer side effects on the microstructure of concrete.Civil Engineering and Geoscience
Physical education in aid of health education using the test «SF-36» as a monitoring of the healthy condition of students
No full textNestorova D. Physical education in aid of health education using the test «SF-36» as a monitoring of the healthy condition of students / D. Nestorova, T. Koleva // Проблеми формування здорового способу життя у молоді: зб. матеріалів VI Всеукр. наук.-практ. конф. молодих учен. та студ. з міжнар. участю, Одеса, 5-6 листоп. 2013 р. / ОНАХТ, Пром. торг. компанія Шабо.-О., 2013. – P. 5-6 : fig
Managing multiple spaces
No full textThis paper is about our experiences of space in the Equator project (www.equator.ac.uk), in particular, the way in which multiple spaces, both virtual and physical, can co-exist. By this we mean that people and objects may have locations in and relationships to both physical space and one or more virtual spaces, and that these different spaces together interact to give an overall system behaviour and user experience. The concepts we develop in this chapter are driven partly by practical experience, and partly by previous theoretical work such as the models and taxonomies of spatial context in (Dix et al., 2000), the models for mixed reality boundaries (Koleva et al., 1999) and capturing human spatial understanding exposed in sources such maps, myths and mathematics (Dix, 2000). We are also building on established work on informal reasoning about space from the AI and GIS communities (Grigni et al, 1995; Papadias et al., 1996) similar to Allen’s well known temporal relations (Allen, 1991)
Le Currency board comme institution: une comparaison des expériences bulgare, estonienne et lithuanienne
No full textLe Currency board comme institution: une comparaison des expériences bulgare, estonienne et lithuanienne
No full textUCDS IN THE COMA CLUSTER
No full textAs part of the HST/ACS Coma Cluster Treasury Survey, we have undertaken a Keck/LRIS spectroscopic campaign to determine membership for faint dwarf galaxies. In the process, we discovered a population of Ultra Compact Dwarf galaxies (UCDs) in the core region of the Coma Cluster. At the distance of Coma, UCDs are expected to have angular sizes 0.01 <R-e <0.2 arcsec. With ACS imaging, we can resolve all but the smallest ones with careful fitting. Candidate UCDs were chosen based on magnitude, color, and degree of resolution. We spectroscopically confirm 27 objects as bona fide UCD members of the Coma Cluster, a 60% success rate for objects targeted with M-R <-12. We attribute the high success rate in part to the high resolution of HST data and to an apparent large population of UCDs in Coma. We find that the UCDs tend to be strongly clustered around giant galaxies, at least in the core region of the cluster, and have a distribution and colors that are similar to globular clusters. These findings suggest that UCDs are not independent galaxies, but rather have a star cluster origin.</p
Medical costs of glaucoma and ocular hypertension in Italian referral centres: a prospective study
No full textAim: This study analyzes the resource utilization and costs of ocular hypertension and glaucoma (staged by severity) in Italian ophthalmology departments. Methods: The project was a multi-centre observational study conducted in 17 Italian ophthalmology departments throughout the country. A total of 659 patients were recruited and followed prospectively for 1 year. For the purpose of analysis, the patients were divided into 3 groups according to the severity at onset: ocular hypertension, glaucoma and advanced glaucoma. Results:The subgroups differed significantly in the main demographic and clinical variables. As expected, greater severity was associated with older mean age and worse visual acuity, and with higher resource consumption and costs. The annual average cost per patient was EUR 788.7 and rose significantly with disease severity (EUR 572.0 for ocular hypertension, EUR 734.3 for glaucoma and EUR 1,054.9 for advanced glaucoma). Drugs and specialist consultations were by far the largest cost components. Conclusions: This study offers some information on the medical costs of glaucoma in Italy potentially useful for decision-making in the health care services. Health care resources and costs increased with disease severity
BVOC emissions, photosynthetic characteristics and changes in chloroplast ultrastructure of Platanus orientalis L. exposed to elevated CO2 and high temperature
No full textDevelopment of Smart Corrosion Inhibitors for Reinforced Concrete Structures Exposed to a Microbial Environment
No full textReinforced concrete deterioration due to acidification of the environment from microbial activity in view of steel performance is seldom reported and still a debate. An initial scrutiny of several inhibitors indicated methylene blue dye and trisodium-phosphate as the most promising candidates for mild steel protection in diluted H2SO4. Such compounds were combined together into two organic/inorganic hybrids composed of hydroxyapatite (HAP) or vaterite porous matrixes impregnated with methylene blue dye. The novel hybrid systems were characterized by means of scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis. The electrochemical response of steel specimens in a simulated environment containing loaded and empty HAP host was monitored by means of linear polarization resistance and electrochemical impedance spectroscopy. The results confirmed the inhibitive properties of the chosen compounds in acidic medium, pointing out a synergistic effect resulting from the release of the organic compound and the dissolution of the inorganic matrix
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