Analysis and conservation of modern modeling materials found in Auguste Rodin's sculptures     

Juliette Langlois  Guylaine Mary  Hélène Bluzat  Agnès Cascio  Nathalie Balcar  Yannick Vandenberghe 《文物保护研究》2017,62(5):247-265

Prior to the exhibition Portrait-making, Rodin and his models (2009), the Rodin museum wanted to restore two busts of Hanako and Clemenceau. Interestingly, these two sculptures contain pieces of modern modeling materials (MMMs) invented at the end of the nineteenth century as an alternative to clay or waxes. The poor state of conservation of the two portraits made any handling and exhibition impossible. Accordingly, the purpose of this article is twofold: to contribute to technical art history and conservation. Elemental and chemical analyses were done on samples from 12 sculptures (SEM–EDX, FTIR, GC–MS, GC–FID, XRD, synchrotron-based µXRF, µXANES, and µFTIR) aimed at identifying the composition of MMMs used by Rodin on plaster sculptures and establishing hypotheses about the origins of their degradation. This thorough study of their composition and degradation was necessary to implement an appropriate restoration plan. The development of conservation protocols adapted to such materials is rarely documented. Different tests were performed on mock-ups (pH, solubility, adhesion, consolidation, and cleaning). In particular, a protocol based on laser cleaning was developed and successfully applied to remove superficial dust and crusts so that the sculptures regained their original aspect.  相似文献   

Cytocompatible cellulose nanofibers from invasive plant species Agave americana L. and Ricinus communis L.: a renewable green source of highly crystalline nanocellulose     

Evdokimova  Olga L.  Alves  Carla S.  Krsmanović Whiffen  Radenka M.  Ortega  Zaida  Tomás  Helena  Rodrigues  João 《Journal of Zhejiang University. Science. B》2021,22(6):450-461

In this study, the fibers of invasive species Agave americana L. and Ricinus communis L. were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers. Cellulose nanofibers were obtained by two methods, based on either alkaline or acid hydrolysis. The morphology, chemical composition, and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM) together with energy-dispersive X-ray spectroscopy(EDX), dynamic light scattering(DLS), X-ray diffraction(XRD), and Fourier transform infrared(FTIR)spectroscopy. The crystallinity indexes(CIs) of the cellulose nanofibers extracted from A. americana and R. communis were very high(94.1% and 92.7%, respectively). Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T) cells were also performed. The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e., 0-500 μg/mL). Our results showed that the nanocellulose extracted from A. americana and R. communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.  相似文献   

Supporting children's participation in second‐language stories in an Irish‐language preschool     

Máire Mhic Mhathúna 《Early Years: An International Journal of Research and Development》2008,28(3):299-309

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The development of analogical reading in Spanish     

Núria Sebastian-Gallés  Ana Parreño Vacchiano 《Reading and writing》1995,7(1):23-38

The use and development of analogical processes in learning to read in Spanish are presented. In the first experiment, the results show that children of 6 years old show analogical effects in reading pseudowords and that the magnitude of this effect is the same as with 10 years old children. However, it is found that children of 10 years old make many lexicalizations when reading pseudowords (about 50% of the items). In experiment 2 this finding is further analyzed. The results show that 9 years old children make more lexicalizations than adult control subjects do. It is suggested that the development of analogical procedures is a fast process (6 years old children already have done it), but that the precise control of lexical information over perceptual one is a later process.  相似文献   

The Use of Different Translation Devices to Analyze Knowledge-Building in a University Chemistry Classroom     

Barreto  Lucas Passos  Rodrigues  Adriana Araújo Dutra  de Oliveira  Giordanna Camilla Bié  de Almeida  Laila Thayanne Gomes  Felix  Matheus Augusto Campelo  Silva  Penha de Souza  Quadros  Ana Luiza  Macedo  Andrea Mara  Mortimer  Eduardo Fleury 《Research in Science Education》2021,51(1):135-152

Research in Science Education - This research draws on Legitimation Code Theory (LCT) to understand the epistemic dimension of the higher education classroom discourse of a professor who is well...  相似文献   

Uncertain Foundations     

Ferreirós  José 《Metascience》2004,13(1):79-82

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Developing and assessingPracticing Spoken French: A multimedia program for improving speaking skills     

Isabel Borrás 《Educational technology research and development : ETR & D》1993,41(4):91-103

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They have gone,and now what? Understanding re-enrolment patterns in the Catalan public higher education system     

David Rodríguez-Gómez  Julio Meneses  Joaquín Gairín  Mònica Feixas  José Luís Muñoz 《高等教育研究与发展》2016,35(4):815-828

Studies of student re-enrolment patterns in higher education constitute, along with traditional studies of persistence and dropout, a key element for improving the quality of higher education institutions. However, these studies tend to be limited as they are centred on a single institution, due to the lack of national-scale data sets for monitoring students between different institutions. Using a longitudinal population-based data set provided by the Catalan University Assurance Agency (AQU), which includes information records on 21,473 undergraduate students, this paper aims to develop and test an exploratory model of student re-enrolment, specifically in the Catalan public university system. We are not only interested in student re-enrolment, but also in whether they do so during the first year after dropout or in the same area of knowledge. Results from logistic regression analysis revealed that although most students return to the university system in the first year after dropout, many of these change to a different area of knowledge, which is clear evidence of dysfunctional and inefficient guidance systems and university entrance. Findings provide a more accurate and complete picture of student re-enrolment behaviour and suggest the need to develop targeted policies to improve the efficiency and effectiveness of our university systems.  相似文献   

A Framework for Epistemological Discussion on Integrated STEM Education     

Ortiz-Revilla  Jairo  Adúriz-Bravo  Agustín  Greca  Ileana M. 《Science & Education》2020,29(4):857-880

Science & Education - In primary and secondary schools, the disciplines encompassed in “STEM”—Science, Technology, Engineering and Mathematics—have usually been studied...  相似文献   

Higher education policies in Brazil: 1970–90     

Lúcia Klein  Simon Schwartzman 《Higher Education》1993,25(1):21-34

Under the authoritarian regime, policies on higher education were mostly produced by the Excutive. First of all, an Educational Reform made up for the rapid expansion of a huge private sector where small teaching institutions prevail and which now absorbs over 60% of Brazilian students. The public sector, in turn, was substantially improved: the number of full time faculty increased and teachers in the federal universities were encouraged to apply for a M.A. or a Ph.D. and to get involved with research activities. Meanwhile, a dual funding system (teaching and research) emerged which was responsible both for the creation of graduate programmes all over the country and for the expansion of a research infrastructure. The civilian government (1985 on) brought policy making out of the bureaucracy and into the Congress. The new Constitution granted the university a degree of autonomy it had never enjoyed before which, however, is still to be regulated by further legislation. Policy initiatives driving at institutional differentiation and at performance assessment have systematically failed to become effective due to resistances within the university itself. Meanwhile financial stringency at a time of recession necessarily leads to reductions in funding, notably for research.  相似文献