Pollutants and their potential degradation of paintings have been measured for the first time in microclimate frames (mc-frames), which are used to protect paintings. The pollutants that were measured include both inorganic pollutants, which originate mainly from external sources, and organic pollutants from mainly internal sources. Those originating from the outdoors enter rooms and subsequently mc-frames at a rate depending on the ventilation rates (air exchange rates) of the mc-frames. The concentration of gaseous pollutants emitted within the mc-frames will depend on net emission rates of the materials used to make the mc-frames, their design, and their ventilation rates. In the EU PROPAINT project measurements of gaseous air pollutants and climatic conditions were performed at various locations both inside and outside different state-of-the-art mc-frames. Diffusive passive pollution gas samplers were used together with different types of dosimeters. Results show that the dosimeters respond to either the photo-oxidizing conditions or the level of volatile organic acids in the environments both in the museums and within the mc-frames. Two dosimeters, the Early Warning Organic (EWO) made from a synthetic polymer and the Resin Mastic coated Piezo electric Quartz Crystals (RM-PQC) respond to photo-oxidation and showed higher values outside than inside the mc-frames. Two other dosimeters, the Glass Slide Dosimeter (GSD) and the Lead coated Piezo electric Quartz Crystals (L-PQC) respond to volatile organic acids and yielded higher values inside than outside the mc-frames. This study emphasizes the need for further work to determine environmental damage functions for paintings, in particular for the effects of organic acids. Such information is essential for the evaluation of the protective effects of mc-frames for paintings. The use of mc-frames is increasing and it is very important to know that this protective measure does not introduce new risks. 相似文献
The purpose of this work was to determine if public communication of science and technology (PCST) has any influence on people's decision to become dedicated to scientific research. For this reason, a national survey involving 852 researchers from all disciplines was conducted in Argentina. The results showed that the factors affecting scientific vocation are many, and that, regardless of differences in gender, age or discipline, the greatest influence on the decision to go into scientific research is exerted by teachers. The analysis also demonstrated that different manifestations of PCST (science books, press articles, audiovisual material, and activities such as visits to science museums) play a significant role in awakening the vocation for science. From these results it may be stated that PCST--in addition to its function of informing and forming citizens--exerts a significant influence in fostering scientific vocation. 相似文献
This paper studies the social side of pre-service teacher education and draws on social network analysis to explore the relation between the social capital of pre-service teachers and their academic and professional success. An online survey was applied to a sample of 321 students enrolled full time either in Preschool Education or Primary Education programmes at the Ramon Llull University-FPCEE Blanquerna in Catalonia, Spain. The instrument consisted of a combination of social network questions and rating scale attributes. Findings allow us to understand the relationship between aspects of the cohort’s social network and key development constructs and demonstrate the importance of considering informal interactions within the programme to improve the performance of pre-service teachers. 相似文献
This study employed open-ended questions on a survey, a focus group interview and participant observations to document the perspectives of Latina paraeducators concerning the challenges and support systems they encountered in order to complete college and gain admission to a teacher certification program. Findings reveal that their challenges included a lack of knowledge about higher education, unresponsive institutional bureaucracies, and the need for financial aid. Family and a cohort group of peers were identified as important sources of support and motivation. As a result of the struggles they experienced these paraeducators expressed a strong commitment of helping others to pursue academic and professional goals. This work highlights the need to critique and transform fundamental inequities within institutional structures that obstruct equal educational opportunities and hinder the recruitment of bicultural teachers.These authors are affiliated with Department of Elementary and Bilingual Education, California State University Fullerton, CA. 相似文献
It is well documented in the literature that early pre-K reading experiences prepare children for the benefits of formal literacy instruction in the later grades. This is particularly true for young children from nonmainstream backgrounds. The objective of this article is to share the findings of a 4-year qualitative study investigating the relationships forged and teaching ideologies constructed by Latino pre-K teachers via critical “storying” within a culturally responsive professional learning community. Findings suggest that as teachers learned to recognize, listen to, and learn from the personal/professional individual and collective life histories of each other, their teaching efficacy was enhanced increasing their ability to develop effective literacy instruction that was culturally and linguistically responsive to the needs of young children. 相似文献
Early Childhood Education Journal - Head Start (HS) teachers are central to providing constructive adult–child interactions that prepare preschool-age students for school and future... 相似文献
Due to its fundamental role for the consolidation of Maxwell’s equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory–experiment relationship). Despite the consensus among physics educators concerning the relevance of the topic, there are many possible ways to interpret and justify the need for the displacement current term. With the goal of understanding the didactical transposition of this topic more deeply, we investigate three of its domains: (1) The historical development of Maxwell’s reasoning; (2) Different approaches to justify the term insertion in physics textbooks; and (3) Four lectures devoted to introduce the topic in undergraduate level given by four different professors. By reflecting on the differences between these three domains, significant evidence for the knowledge transformation caused by the didactization of this episode is provided. The main purpose of this comparative analysis is to assist physics educators in developing an epistemological surveillance regarding the teaching and learning of the displacement current. 相似文献
The aim of this work was to compare the curricula of three different agricultural engineering courses and to determine the competence of graduating students in three subject areas in order to identify possible shortfalls in the number of hours of instruction (HI) required for full competence to be attained.
A total of 132 students sat a voluntary examination in the final year of their studies to determine their competence in three subject areas: electrical facilities, machinery and construction. The degree courses completed by these students are meant to provide them with the legal standing required to undertake infrastructure projects in agricultural installations.
This work detected significant differences in the competence of graduates in the mentioned subjects, depending on the number of HI they had received. Students who had received under 120 HI in these subjects were found to be significantly less competent than those who had received more. 相似文献
Abstract The aim of this study was to examine differences in traditional heart rate variability measurements and heart rate complexity (sample entropy) in young adults grouped by objectively measured achievement of either moderate or both moderate and vigorous physical activity recommendations. Of 168 young adults tested (86 females, 82 males; age 20.5 ± 1.2 years), 119 achieved only recommendations for moderate physical activity (moderate group) and 49 achieved recommendations for both moderate and vigorous physical activity (vigorous group). Analysis of covariance controlling for sex, weekly minutes of moderate physical activity, and percentage of body fat was used to assess between-group differences in heart rate variability and heart rate complexity. Logistic regression analysis was used to determine the group characteristics that best predicted high heart rate complexity and vagal indices of heart rate variability. The majority of the autonomic measures were higher (P < 0.05) in the vigorous group, and regression analysis showed that vigorous physical activity was the only multivariate predictor of higher heart rate complexity and higher heart rate variability. Young adults engaged in regular vigorous physical activity were more than twice as likely to have high heart rate complexity than those involved in predominantly moderate exercise. These findings suggest that vigorous physical activity is more closely associated with high heart rate complexity than moderate physical activity in young adults. 相似文献