17,950 research outputs found
An innovative cooperative model for the Master Degree Project of Architecture. Overcoming the traditional system.
http://dx.doi.org/10.4995/HEAD17.2017.6713Although the Bologna’s process has highlighted the need to develop deep and structural changes in the educational institutions, there is a scarce bibliography on innovation projects in Master Degree Projects, specifically in the field of Architecture. This paper is part of a educational innovative reaserch project that is proposing a cooperative process-and-product model-based for MDP. The model is developed in three stages, from collaborative learning action groups to indivual project. At the end of the process the student has developed three documents: a presentation, a product and a daily-portfolio. Finally, MDP assessment is the sum of three evaluationsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Methodology for the metric restoration of the historical cartography applied to Francisco Coello's cartografic series of the Royal Site of Aranjuez
Hojas Kilométricas (Kilometric Sheets). Specifically, the study focuses on those sheets referring to the city centre and surrounding area of the Royal Site of Aranjuez, a town in the south of the Province of Madrid. The aim of this study is to restore the actual size and measurements of scanned images of the Hojas Kilométricas. This would allow us, among other things, to reestablish both the format and scale of the original plans. To achieve this goal it is necessary to rectify and then georeference these images, i.e. assign them a geographic reference system. This procedure is essential in the overlaying and comparison of the Hojas Kilométricas of the Royal Site with other historical cartography as well as other sources related to the same area from different time periods. Subsequent research would allow us, for example, to reconstruct the time-evolution of the urban area, to spot new construction and to pinpoint the locations of any altered or missing buildings or architectural features. In addition, this would allow us to develop and integrate databases for GIS models applicable to the management of our cultural heritage
Clinkering and hydration study of non-active and active Belite-Alite-Ye'elimite (BAY) cements
The aim of AIM is to promote industry-driven, interdisciplinary research in material science and engineering in order to provide leading-edge, sustainable solutions to the challenges facing engineers in today’s changing society and environment. http://www.ucl.ac.uk/aim/conference-info/37ccsThe manufacturing process of ye'elimite rich cements emit about 15-37% less CO2 to the atmosphere than OPC. Cements that contain belite, ye’elimite and ferrite, known as BYF cements, are promising eco-friendly binders. However, belite, their main phase, shows a slow hydrating behaviour; therefore the corresponding mortars present lower mechanical strengths than OPC at early ages. To solve this problem, BYF clinkers can be activated by: i) forming alite jointly with belite and ye’elimite during clinkering, known as BAY clinkers. The alite and ye’elimite reaction with water should develop high mechanical strengths at early ages, besides, belite contributes to later curing times. ii) A second activation is based on the stabilisation of alpha forms of belite by dopants. The objective of this work is to obtain two types of BAY clinkers (standard and active BAY) using CaF2 as mineraliser and borax as dopant agent to stabilize alpha forms of belite phase. After that, anhydrite was added as sulphate source to obtain the corresponding cements. The hydration behaviour of these cements has been studied through rheological and x-ray diffraction measurements, the latter combined with Rietveld quantitative phase analysis. In addition, mechanical and dimensional properties of BAY mortars are also presented and discussed.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Osteosarcoma extraóseo Presentación de 1 caso y revisión de la literatura
Se presenta un caso de los no frecuentes osteosarcomas extraóseos, con localización
en el muslo y que cursó con varias recidivas hasta su fallecimiento por metástasis pulmonares.
En la revisión de la bibliografía se puede comprobar que este tipo de tumores tienen una malignidad
mayor de la habitualmente reconocida, estando en algunos casos en relación con el empleo
de radiaciones ionizantes, con miositis osificantes, con extravasación de líquidos de contraste
y con inyecciones intramusculares. Su único tratamiento es la exéresis ablativa, aunque tienen una
alta tasa de recidivas.A case of extraosseous osteogenic sarcoma siting in the thigh with a warming
follow-up because he was complicated with several recurrences within two years until his exitus
is reported. In the revision of the literature is common to see that this tumour has a worse
malignant behaviour, and has also a clear relationship in some cases with the use of radiations,
with myositis ossificans following intramuscular inyection or by extravessels liquid inyection.
The treatment must be a complete ablative surgery although the number of recurrences is
ussually high
Rietveld Quantitative Phase Analysis of Oil Well Cement: in Situ Hydration Study at 150 Bars and 150 °C
Oil and gas well cements are multimineral materials that hydrate under high pressure
and temperature. Their overall reactivity at early ages is studied by a number of techniques
including through the use of the consistometer. However, for a proper understanding of the
performance of these cements in the field, the reactivity of every component, in real‐world
conditions, must be analysed. To date, in situ high energy synchrotron powder diffraction studies
of hydrating oil well cement pastes have been carried out, but the quality of the data was not
appropriated for Rietveld quantitative phase analyses. Therefore, the phase reactivities were
followed by the inspection of the evolution of non‐overlapped diffraction peaks. Very recently, we
have developed a new cell specially designed to rotate under high pressure and temperature. Here,
this spinning capillary cell is used for in situ studies of the hydration of a commercial oil well
cement paste at 150 bars and 150 °C. The powder diffraction data were analysed by the Rietveld
method to quantitatively determine the reactivities of each component phase. The reaction degree
of alite was 90% after 7 hours, and that of belite was 42% at 14 hours. These analyses are accurate,
as the in situ measured crystalline portlandite content at the end of the experiment, 12.9 wt%,
compares relatively well with the value determined ex situ by thermal analysis, i.e., 14.0 wt%. The
crystalline calcium silicates forming at 150 bars and 150 °C are also discussed.This research was funded by Spanish MINECO, grant number BIA2017‐82391‐R which is co‐funded
by FEDER.
We thank Marc Malfois for his help during the experiment performed at NCD‐SWEET
beamline at ALBA synchrotron. We also thank Marcus Paul (Dyckerhoff GmbH) for providing the OWC
sample with its characterization and helpful discussions
Early hydration study of standard and doped Alite-Belite-Ye’elimite (ABY) cements through Synchrotron Radiation
The manufacturing of ye'elimite-rich cements releases from 15 to 37%, depending on their
composition, less CO2 to the atmosphere than ordinary Portland cement (OPC). BYF cements
containing belite, ye’elimite and ferrite as main crystalline phases, are promising eco-friendly binders.
Nevertheless, belite, its main phase, shows a slow hydrating behaviour and the mechanical strengths
are lower than OPC at early ages. Some alternatives to solve this problem are: i) forming alite jointly
with belite and ye’elimite during clinkering, Alite Belite Ye’elimite (ABY) clinkers. The hydration of alite
and ye’elimite would develop high mechanical strengths at early ages, and belite contributes to later
curing times; ii) a second alternative is the stabilisation of alpha forms of belite using dopants such as
boron named here after dABY.
In this work, two different types of ABY clinkers (standard and doped) have been prepared and
characterized to understand their different hydration mechanisms at the same water-to-cement (w/c)
ratio. The clinkers have been prepared using CaF2 and ZnO as mineralizers, and borax as dopant
agent to stabilize alpha forms of belite (’H-C2S). Afterwards, 14 wt% of anhydrite (as soluble sulphate
source) was added to prepare the corresponding cements. Finally, the hydration study was performed
at w/c ratio of 0.5. Here, an in-situ hydration study using synchrotron X-ray powder diffraction (SXRPD)
for the first 14 hours of hydration is reported. Moreover, these results will be combined with the ex-situ
laboratory X-ray powder diffraction study (LXRPD) at 1 day of hydration and calorimetric results.
Rietveld quantitative phase analysis has been used to establish the phase evolution across the time.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
MINECO ( BIA2017-82391-R), co-funded by FEDER, and I3 [IEDI-2016-0079]
Water-to-cement ratio influence on low-carbon cements performances
Portland Cement (PC) is the most important active ingredient in most of the construction concrete. However, the PC production is associated with a high carbon dioxide release (around 1 ton of CO2 per ton of PC). One approach to reduce CO2 emissions consists on the reformulation of the clinker with less calcite demanding phases, such as, belite rich clinkers. The drawback of this kind of clinkers is the low reactivity of belite (beta-belite). In order to compensate this problem, belite rich clinkers can be prepared with ye’elimite and ferrite or with alite [known as belite-ye’elimite-ferrite (BYF) and belite-alite-ye’elimite (BAY), respectively]. In addition, it can be improved by using a high reactive belite polymorph, such as alpha-belite.
In this work, the hydration and mechanical behaviour of BYF and BAY cements (with beta and/or alpha-belite) with different water-to-cement ratios have been studied. The clinkers were produced using natural raw materials, and were mixed with anhydrite (CaSO4) to prepare the corresponding cements. At early ages, the main hydration products of these cements were ettringite, calcium monosulfoaluminate and amorphous aluminium hydroxide. At later ages, stratlingite, katoite and amorphous C-S-H were found. The compressive strength values of the corresponding mortars were correlated with the mineralogy evolution of the pastes (mainly obtained by XRD and TGA).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
I3-Ramón y Cajal
Universidad de Malag
Advanced synchrotron studies of ye'elimite-based cement pastes
Synchrotron characterization techniques [1] are being used to study Portland-based cements and recently also CSA and related cements. A key property of these techniques is that they do not require sample preparation, so the microstructures of the pastes can be preserved. The classical application of synchrotron tools is powder diffraction used to determine the crystalline phase content evolution with hydration including the overall amorphous fraction. Furthermore, other most advanced techniques are being applied to ye'elimite-containing pastes such as i) Total Scattering Synchrotron Powder Diffraction (TS-SXPD), and ii) Ptychographic Synchrotron X-ray Computed Tomography (PSXCT). All these applications will be reviewed here.
TS-SXPD data coupled with the Pair Distribution Function (PDF) analysis methodology [2] allows having a better insight about the nanocrystalline/amorphous atomic arrangements in the gels. It has been very recently shown that nanogibbsite with very small particles, 3nm, is the main constituent of ye'elimite-gypsum hydration paste [2]. Nanogibbsite particles being smaller than those originated from the hydration of monocalcium aluminate. In addition, PSXCT is a tomographic technique that profits from the partly coherent nature of the synchrotron beam to provide better (smaller) resolution, which can be lower than 100 nm. It also provides the mass densities if the chemical stoichiometries are known. This technique has been applied to ye'elimite hydration to determine the microstructure and chiefly the bulk densities of nanogibbsite [3]. The microstructure evolution at early age was also followed [4]. Figure 1 shows an example of a slide of the electron density tomogram for a ye'elimite paste at 8 days of hydration and the corresponding histogram for the full volume with all phases identified.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.This work has been supported by Spanish MINECO through BIA2014-57658-C2 and BIA2017-82391-R, which are co-funded by FEDER
A near zero consumption building as an urban acupuncture for a vertical slum. A case study in the city of Malaga, Spain
Vertical slum is defined as a particularly vulnerable height building, with serious problems of functionality, safety and habitability. Venezuela’s Tower of David is a famous example. Vertical slums are associated with an important level of physical degradation, coupled with a precarious socioeconomic situation of its occupants. Their inability to create a community for proper and mandatory maintenance increases their physical deterioration. The abandonment of the original owners is replaced by a system of occupation and illegal activities. In many cases, with an interest in maintaining the building in a state of precariousness, which annuls any attempt to rehabilitate it
Facing this situation, the intervention is proposed through an urban acupuncture project, understood as a project of expropriation and physical rehabilitation of the building, associated to a project of social rehabilitation in a disadvantaged environment. It is about creating a hybrid building associated with four objectives
1- Create a hybrid building with a mixed offer of social and housing services: sheltered housing for seniors, residence and accommodation for young entrepreneurs. The idea of a social condenser is related to studies of the hybrid building such as the Downtown Athletic Club in New York, or the Rokade Tower and Maartenshof residence (Groningen, The Netherlands).
2- Incorporate the sustainability parameters directed to a building almost zero.
3- Incorporate a model of provision of housing services, managed by the municipality, but with the possibility of incorporating NGOs
4- Design a social rehabilitation project that facilitates the creation of a web of social-based companies or cooperatives that fosters entrepreneurship, and that can actively participate in the rehabilitation and maintenance of the neighborhood itself.
This paper applies these principles to a building in Malaga as a case study and 10 strategies are developed and analysed in regards to its physical, social and sustainable transformation.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Synchrotron x-ray pair distribution function: A tool to characterize cement gels
Cement matrices contain large amounts of crystalline phases jointly with amorphous and/or nanocrystalline phases. Consequently, their analyses are very challenging. Synchrotron powder diffraction in combination with the pair distribution function (PDF) methodology is very useful to characterize such complex cement pastes. This work is focused on the study of the short and medium range atomic arrangement(s) in the different nanocrystalline gels which are present in the cement pastes through total scattering Pair Distribution Function quantitative phase analyses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Acknowledgments: We thank CELLS-ALBA (Barcelona, Spain) for providing synchrotron beam time and the financial support by BIA2014-57658-C2-1-R and BIA2014-57658-C2-2-R, which is co-funded by FEDER. We also thank Dr. Monica Dapiaggi for her contribution with the PDF study of Ca(OH)2 monolayer
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