Investigations regarding the behaviour of historic glass and its surface layers towards different wavelengths applied for laser cleaning     

Farideh Fekrsanati  Stefan Klein  Jens Hildenhagen  Klaus Dickmann  Yiorgos Marakis  Aleka Manousaki  Vassilis Zafiropulos   《Journal of Cultural Heritage》2001,2(4):187

The application of lasers for the removal of superficial deposits from historic stained glass is a comparatively new field of scientific interest. Experimental studies concerning the behaviour of glass substrates and the corresponding superficial deposits towards different laser wavelengths were carried out. The experiments were performed using wavelengths of λ = 193 nm (ArF-Excimer), 308 nm (XeCl-Excimer), 355 nm (Nd:YAG third harmonic) and 1 064 nm (Nd:YAG fundamental) in comparison to λ = 248 nm (KrF-Excimer). This comparison is due to the fact that the present knowledge is based on the 248 nm wavelength. Specially prepared model glass samples representing the original fragments and samples of organic polymers (formerly used as a protective material for historic stained glasses) were used to study the effects of laser radiation and were subsequently characterised by optical microscopy.  相似文献   

Beeinflussung muskulärer Parameter durch ein zehnwöchiges Dehnungstraining     

Klaus Wiemann 《Sportwissenschaft》1991,21(3):295-306

  相似文献   

Google Scholar and Web of Science: Examining gender differences in citation coverage across five scientific disciplines     

Jens Peter Andersen  Mathias Wullum Nielsen 《Journal of Informetrics》2018,12(3):950-959

Many studies demonstrate differences in the coverage of citing publications in Google Scholar (GS) and Web of Science (WoS). Here, we examine to what extent citation data from the two databases reflect the scholarly impact of women and men differently. Our conjecture is that WoS carries an indirect gender bias in its selection criteria for citation sources that GS avoids due to criteria that are more inclusive. Using a sample of 1250 U.S. researchers in Sociology, Political Science, Economics, Cardiology and Chemistry, we examine gender differences in the average citation coverage of the two databases. We also calculate database-specific h-indices for all authors in the sample. In repeated simulations of hiring scenarios, we use these indices to examine whether women's appointment rates increase if hiring decisions rely on data from GS in lieu of WoS. We find no systematic gender differences in the citation coverage of the two databases. Further, our results indicate marginal to non-existing effects of database selection on women's success-rates in the simulations. In line with the existing literature, we find the citation coverage in WoS to be largest in Cardiology and Chemistry and smallest in Political Science and Sociology. The concordance between author-based h-indices measured by GS and WoS is largest for Chemistry followed by Cardiology, Political Science, Sociology and Economics.  相似文献   

The Human Rights Approach to Education in International Organisations     

Klaus Hüfner 《European Journal of Education》2011,46(1):117-126

In this article, the work of three international governmental organisations (IGOs) dealing with human rights will be discussed, namely the United Nations Educational, Scientific and Cultural Organization (UNESCO), the United Nations Children's Fund (UNICEF)¹ and the Council of Europe (CoE). In the first section, the main characteristics of the three IGOs in terms of similarities and differences will be elaborated. Then, their human rights approach to education will be described, dealing with the legal foundations. In the final section, the different strategies of implementation based on both their official mission statements and their present strategy papers will be evaluated under the heading ‘competition vs. cooperation’.  相似文献   

Physics in upper secondary schools in Denmark     

H. Nielsen  P. V. Thomsen 《International Journal of Science Education》2013,35(2):189-202

This article is the third in a series reporting on the changes in attitudes and interests‐‐mainly with respect to physics‐of several hundred students as they proceed through the Danish upper secondary school (Gymnasium). It concentrates on the results of the final investigation which took place shortly before the students leave the school.  相似文献   

Television: The performance of nonresident students in the “economics U$A” telecourse     

Paul W. Grimes  Joyce E. Nielsen  James F. Niss 《The American journal of distance education》2013,27(2):36-43

Abstract

Correspondence study represents the first and most persistent distance education format in American universities. Later called independent study, it enabled universities to disseminate instruction far beyond their campuses. Yet, national‐level leadership provided by the National University Continuing Education Association (NUEA) and its divisions has been relatively restrained. In contrast, leadership in the private correspondence school sector has been assertive, and sometimes even aggressive. The NUEA and its members shunned this approach, choosing instead to lead by persuasion and example. The NUEA developed standards of practice concerned primarily with replicating on‐campus teaching styles and values, rather than the promotion of distance education. With the abolition of its division structure, the NUEA's successor, the University Continuing Education Association (UCEA), has opted out of a leadership role in independent study. This paper concludes that the NUEA's initial attempt at leadership in distance education— while reasoned and principled—contained flaws that made failure inevitable.  相似文献   

The endless spiral     

Henry Nielsen 《Science & Education》1993,2(2):169-181

A Danish textbook on the history of technology,Skruen uden ende — Den vestlige teknologis historie (The Endless Spiral: A History of Western Technology), was published in 1990. In the present article, one of the authors presents some of the background to this event and puts the work into historical perspective by describing a number of different traditions for writing textbooks on the history of technology. Next follows a discussion of why history of technology ought to be an important ingredient in upper secondary education and why only the contextualist tradition — inspired by the rapidly developing school of research centered around the journalTechnology & Culture — offers any real hope for providing meaningful teaching materials on history of technology. The paper ends with a brief outline of the textbook's contents, with special emphasis on one of its several case studies describing the development of certain mainstream technologies in the context of the scientific, economic, social and cultural developments existing when the particular technology came into being.  相似文献   

The emergence and institutional co-determination of sustainability as a teaching topic in interdisciplinary science teacher education     

Klaus Rasmussen 《Environmental Education Research》2017,23(3):348-364

This paper takes an institutional perspective on the topic of sustainability in order to analyse how this ‘idea’ enters science teacher education through an interdisciplinary approach. It shows how the development and implementation of a course for Danish pre-service teachers was conditioned and constrained by a complex web of interactions in and among the teaching disciplines of biology, geography and physics/chemistry and among the institutions of school, teacher college and university. The data collected are used to identify influences among the disciplines as well as disciplinary differences, conceptualised through a new reference model that separates the analysis from the usual sustainability dimensions. The findings reveal how sustainability as a teaching topic can be a unifying idea in an interdisciplinary setting. Disciplinary differences evidently impact course planning and implementation significantly, but not exclusively. By elaborating on the interactions between these circumstances, the paper provides insight into the processes of developing interdisciplinary teacher education.  相似文献   

How to measure research efficiency in higher education? Research grants vs. publication output     

Sabine Gralka  Klaus Wohlrabe  Lutz Bornmann 《Journal of Higher Education Policy & Management》2019,41(3):322-341

An ongoing debate in the literature on the efficiency of higher education institutions concerns the indicator for research output for use in empirical analysis. While several studies have chosen to use the number of publications as this indicator, others rely on the amount of research grants. The present study investigates whether both measures lead to a similar assessment of universities. In addition, the number of publications belonging to the 10% and 1% most frequently cited papers in the corresponding subject category and publication year are evaluated. We show that there is a high correlation of efficiency values between the estimations using these indicators. This correlation is slightly higher when the efficiency values result from a data envelopment analysis than when they are determined with a stochastic frontier analysis. The results of this study provide helpful guidelines for researchers evaluating the efficiency of universities and are valueable for decision-makers in science policy.  相似文献   

The importance of morphemic awareness to reading achievement and the potential of signing morphemes to supporting reading development     

Nielsen DC  Luetke B  Stryker DS 《Journal of deaf studies and deaf education》2011,16(3):275-288

The ability to access and understand the meaning of multi-morphemic words is essential for age-appropriate literacy growth as well as for achievement in other participants, such as science and social studies, which are so print-dependent. This paper provides a theoretical basis for focusing on the morphology of English when teaching students who are deaf or hard of hearing to read through a review of the literature on the role of morphology in reading for both hearing students and those with a hearing loss. In addition, the authors review the empirical literature on Signing Exact English (SEE), a system of signing English constructed in which the morphology of words is made visible to children who might not be able to hear them. The authors propose that students' use of SEE can provide a bridge to developing the morphemic awareness so necessary for age-appropriate reading development and achievement.  相似文献