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Beatriz Prieto Perla Ferrer Patricia Sanmartín Victor Cárdenes Benita Silva 《Journal of Cultural Heritage》2011,12(4):420
Substitution of slate roofing tiles is a conventional operation during building restoration, since tiles are very difficult to restore or clean because of the high degree of alteration they suffer. Criteria for replacement of historical building stones must be based on geological, geotechnical and esthetic parameters, among which color is of great importance. In this sense, this paper constitutes a comprehensive and useful colorimetric study of roofing slates from the Iberian Peninsula, for the purposes of restoration. The color of 50 commercial varieties of roofing slate mined in quarries from the 12 mining districts in the Iberian Peninsula was analyzed with a spectrophotometer device, by considering the CIELAB color space. The results of the study were used to develop a protocol for characterizing the color of roofing slate and to define the color range of roofing slate from the Iberian Peninsula. In addition, the similarities and differences in the color and microstructure of the different commercial varieties of Iberian roofing slate were established and the limit of acceptability of replacement of one type of slate by another was determined. Parameter hab was found to be the most important CIELAB color coordinate as regards the formation of homogeneous color groups, and the specular component excluded (SCE) mode was most sensitive as regards detecting color differences between two samples. 相似文献
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The purpose of this study was to investigate the factors associated with teenagers’ willingness to volunteer with elderly persons using an expanded model of the Theory of Planned Behavior (TPB). Participants consisted of 258 ninth-grade students at a large high school in the northern part of Israel. Participants completed a structured questionnaire consisting of 52 items, which examined their attitudes, subjective norms, perceived behavioral control, past behavior, personal identity, and perceived moral obligation. Their willingness to volunteer with elderly persons was assessed using six vignettes, varying in the severity of the elderly person's health and functional conditions described. Additionally, the students’ sociodemographic variables were examined. Overall, students’ willingness to volunteer with elderly persons was low; however, it increased when the elderly person in the vignette was described as relatively healthy. Statistically significant relationships were found between willingness to volunteer and personal identity, as well as between willingness to volunteer and attitudes toward volunteering with elderly persons. A statistically significant but moderate relationship was found between willingness to volunteer and subjective norms. Multiple regression analyses showed that attitudes, subjective norms, and personal identity were the main predictors of willingness to volunteer with elderly persons, explaining 58% of the variance. The expanded model of the Theory of Planned Behavior provided an appropriate framework for understanding the factors associated with teenagers’ willingness to volunteer with elderly persons. Our findings stress the need to develop educational intervention programs regarding gerontologically-related subjects and to disseminate them among the population in general, and among youth in particular. 相似文献
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Monica Favaro Pietro A. Vigato Alessia Andreotti Maria Perla Colombini 《Journal of Cultural Heritage》2005,6(4):295-305
The oil painting “La Medusa” executed by Caravaggio at the end of the XVI century on a wooden shield, was investigated by integrated physical–chemical and analytical methodologies in order to obtain scientific data capable of elucidating the state of conservation and the painting technique. Optical (OM) and electronic (SEM-EDS) microscopy, micro-FT-IR spectroscopy, gas chromatography–mass spectrometry (GC–MS) and pyrolysis GC–MS were applied on two microfragments and some organic samples obtained by solvent extraction using the swab cleaning technique. The obtained results indicated that Caravaggio probably reused an old shield as a previous gypsum preparation layer has been detected under the original painting layers. He used white lead, natural earths, verdigris and lead–tin yellow type I mixed with drying oils to paint. The considerable amount of amorphous particles of copper chlorides found in the green pigment verdigris suggests that it could have been produced according to the ancient recipe of verde salsum described by Theophilus. Mordant gilding has been identified on the upper part of the shield that can be related to an abandoned experiment to give the painting a mirror-like reflecting effect. Three different varnishes layers have been detected above the painted surface. The original and restoration varnishes have been identified and they contain a mixture of drying oil, mastic and turpentine and some beeswax. Cleaning tests, performed with different organic solvents, suggest the use of isopropyl alcohol as cleaning agent because it is less efficient in comparison to others solvents; thus it ensures a careful and controlled removal of the varnishes. 相似文献
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Kamilla B. Kalinina Ilaria Bonaduce Maria Perla Colombini Irina. S. Artemieva 《Journal of Cultural Heritage》2012,13(3):259-274
This paper presents the first extensive investigation of the composition of both the organic and inorganic media used by Lorenzo Lotto, one of the outstanding artists of the Italian Renaissance in the early 16th century. By investigating four paintings from The State Hermitage Museum collection (Saint-Petersburg, Russia), new insights into the artist's painting techniques were obtained, which contribute to our understanding of the transition from egg tempera to oil painting techniques that took place in Italian paintings between the 15th to the mid 16th century. Inorganic materials were determined using SEM-EDX and PLM, revealing information on the artist's palette. Of particular note was the powdered colourless glass found in the priming layer of the Madonna delle Grazie, which was most likely used as dryer. Organic materials were analysed in individual paint layers using GC-MS, and revealed a mature use of drying oils as paint binders, skilfully mixed with other organic materials and inorganic driers, to obtain the desired aesthetical and technical qualities of the paint. The study revealed that Lotto used the tempera grassa technique through most of his creative life. 相似文献
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Schemes are said to underly cognitive processes, including problem solving in Mathematics. An attempt to test the impact of schemes in solving 2-step word-problems was made in an instructional study where two computerized environments were compared. In the S.P.A. (Schemes for Problem Analysis) software, the user works with schemes in order to analyze and solve the problems. When using S.P.A., the solver has to fill in the data in a scheme which is presented graphically. From the scheme the operation is derived in a deterministic manner, and the user (solver) can then calculate the solution. A feedback mechanism follows. In the A.P. (Algebraic Proposer) software the user fills in a table with the data given in the word-problem and then has to find out which operation to use in order to find the solution. The effectiveness of S.P.A. vs. A.P. was empirically examined in an instructional experiment which studied two sixth grade classes during a four month period. The results of the experiment concluded that, in solving easy word problems, both of the two software systems were equally helpful. In harder word-problems, however, those who learned with the S.P.A. experienced more success than those who had learned with A.P. It was also found that S.P.A. was more instrumental in helping low achieving students cope with hard word-problems. 相似文献
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The process of transition from a novice's state to that of an expert, in the constrained domain of decimals, is described in terms of explicit, intermediate, and transitional rules which are consistent, yet erroneous. These rules can be traced to former rules already established in earlier knowledge domains. Empirical data from children at grades 6, 7, 8 and 9 will demonstrate the evolution of an expert's knowledge through an elaborated learning path. 相似文献
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Ilaria Bonaduce Catharina Blaensdorf Patrick Dietemann Maria Perla Colombini 《Journal of Cultural Heritage》2008,9(1):103-108
The “Terracotta Army” is a worldwide known archaeological finding in China. It is a part of the burial complex of the emperor Qin Shihuangdi (259–210 BC), which is still under excavation and study. The fact that the sculptures, chariots and weapons of the First Chinese Emperor's Terracotta Army were originally all painted in bright colours is still not widely known. The chemical characterisation of the paint medium was performed through an analytical procedure based on GC-MS. The proteinaceous binder was identified for the first time through a desalting procedure used in proteomics. The identification of egg as a paint binder is extremely interesting in terms of the historical significance of the work of art itself and important in terms of the method of conservation. Moreover it represents one of the first steps towards an understanding of the painting technique used on ancient sculptures in China, of which – despite their fame – nothing is yet known. 相似文献
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Jiang Yang Popov Vitaliy Li Yaoran Myers Perla L. Dalrymple Odesma Spencer Joi A. 《Journal of Science Education and Technology》2021,30(6):877-888
Research suggests that the likelihood of students entering into science, technology, engineering, and mathematics (STEM) careers can be increased by promoting and maintaining students’ interest in STEM during middle school years, a critical developmental stage when students’ interests begin to solidify. One way to attract students to STEM is through technology-enhanced learning environments and experiences, which can spark and cultivate the long-term interest needed to pursue STEM careers. Virtual reality (VR) can potentially increase access to such STEM-related experiences for all students due to its educational and technological affordances. Currently, there has been little exploration of the intersection between VR and career development for K-12 students. This study, therefore, aims to address this gap by exploring the use of VR 360 videos for STEM career exploration. Data were collected using focus group interviews with 39 primarily Latinx middle school students who participated in the summer enrichment program. These interviews were conducted immediately after a VR 360 video activity that featured female characters and/or characters from racial minorities in order to best support students who are underrepresented in STEM fields. The findings support the potential of VR as a tool for career development as long as content, possible physical side effects, and scaffolding are considered. The implications for research and practice are discussed.
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