Guido Van Hooydonk

Methods for accrediting publications to authors or countries: consequences for evaluation studies

One aim of science evaluation studies is to determine quantitatively the contribution of different players (authors, departments, countries) to the whole system. This information is then used to study the evolution of the system, for instance to gauge the results of special national or international programs. Taking articles as our basic data, we want to determine the exact relative contribution of each coauthor or each country. These numbers are then brought together to obtain country scores, or department scores, etc. It turns out, as we will show in this article, that different scoring methods can yield totally different rankings. In addition to this, a relative increase according to one method can go hand in hand with a relative decrease according to another counting method. Indeed, we present examples in which country (or author) c has a smaller relative score in the total counting system than in the fractional counting one, yet this smaller score has a higher importance than the larger one (fractional counting). Similar anomalies were constructed for total versus proportional counts and for total versus straight counts. Consequently, a ranking between countries, universities, research groups or authors, based on one particular accrediting method does not contain an absolute truth about their relative importance. Different counting methods should be used and compared. Differences are illustrated with a real-life example. Finally, it is shown that some of these anomalies can be avoided by using geometric instead of arithmetic averages.

Investigation of pigments in medieval manuscripts by micro Raman spectroscopy and total reflection X-ray fluorescence spectrometry

Analytical pigment investigation can reveal important information for art-historians. The use of two micro-analytical techniques, micro Raman-spectroscopy and total reflection X-ray fluorescence, is shown to be very successful. These techniques give complementary information: Raman spectroscopy allows the identification of the different materials the pigment grains consist of, and total reflection X-ray fluorescence gives the average elemental composition of the sample.The latter is helpful to distinguish between the different palettes used by different artists or workshops. Samples can be taken with cotton wool swabs (Q-tips), which cause no visible alteration to the artefact. Such a sample allows both Raman-spectroscopy and total reflection X-ray fluorescence to be applied using less than 1 μg of material. This approach is illustrated with the pigment investigation of seven late-medieval Mercatellis manuscripts, kept in the Ghent University Library.

Cuban scientific articles in ISI Citation Indexes and CubaCiencias databases (1988-2003)

SummaryThis comparative study covers the period 1988-2003 of the Institute for Scientific Information Databases (ISI-DBs), CD-ROM edition: Science Citation Index (SCI), Social Sciences Citation Index (SSCI) and Arts & Humanities Citation Index (A&HCI) as international databases and from the CubaCiencias (CubaCiencias) as an internal database. The number of articles published in Cuban journals, ISI-DBs, the author associativeness trend, the most important institutions and other indicators are collected. However, it is observed that CubaCiencias and ISI-DBs are not perfectly suitable for a study of the productivity of Cuban authors. It is necessary to properly standardize the author fields. For bibliometric studies, Cuba needs a database not only for the published papers in Cuban journals, but also for all the papers published by Cuban authors.This comparative study covers the period 1988-2003 of the Institute for Scientific Information Databases (ISI-DBs), CD-ROM edition: Science Citation Index (SCI), Social Sciences Citation Index (SSCI) and Arts & Humanities Citation Index (A&HCI) as international databases and from the CubaCiencias (CubaCiencias) as an internal database. The number of articles published in Cuban journals, ISI-DBs, the author associativeness trend, the most important institutions and other indicators are collected. However, it is observed that CubaCiencias and ISI-DBs are not perfectly suitable for a study of the productivity of Cuban authors. It is necessary to properly standardize the author fields. For bibliometric studies, Cuba needs a database not only for the published papers in Cuban journals, but also for all the papers published by Cuban authors.

A Universal Two-Parameter Kratzer-Potential and Its Superiority over Morse's for Calculating and Scaling First-Order Spectroscopic Constants of 300 Diatomic Bonds

After decades of intensive research, the question remains relations between the constants. We show that ionic potentials of generalized Kratzer-type (Varshni’s Vth whether or not a universal twoor three-parameter potential exists. For a large number of about 300 bonds, we now potential) and their ionic Coulomb-like asymptotes Ae/Re (with A close to 1) behave as simple universal two-parameter critically review the constraints for potentials and asymptotes, involved in three available scaling processes potentials. For both αe and ωexe, this potential gives percentage deviations 2 to 3 times smaller than Morse’s three (Varshni, Calder–Ruedenberg, and Graves–Parr). We show that the covalent Sutherland parameter can never be a parameter potential for hundreds of bonds. We also prove that the Graves–Parr scaling hypothesis is valid, despite universal scaling factor. This implies that the usual constraint U(R) = –De at R = ` for potentials is only desirable and that these authors’ own conclusion. We discuss various new relations between spectroscopic constants. the natural asymptote De is not even needed to explain the

A TXRF and Micro-Raman Spectrometric Reconstruction of Palettes for Distinguishing Between Scriptoria of Related Medieval Manuscripts

Assigning related medieval manuscripts to different workshops on the basis of codicological characteristics, is not straightforward. We present the first attempt to distinguish between scriptoria by means of a large-scale total reflection X-ray fluorescence (TXRF) analysis of pigment elements and an identification of pigment molecules with micro-Raman spectroscopy. We analyzed 324 colored items in 10 medieval manuscripts, of which 7 are folio-sized illuminated manuscripts, all ordered by Raphael de Mercatellis in the late 15th and early 16th century. Palettes in miniatures were not yet examined. Blue palettes are exclusively azurite-based and are easily differentiated by means of the respective amounts of Ti, Ba, and As. Differences for green palettes are also pronounced. The green Cu-based pigment was not yet identified, but it certainly is not malachite or verdigris. Red pigments used are HgS, vermilion, and Pb3O4, red lead. The Flemish gold-leaf technique is used. The 7 Mercatellis manuscripts show two different palettes, both different from the non-Mercatellis manuscripts. The grouping of the Mercatellis manuscripts according to date and to palettes is, in general, consistent with a grouping on the basis of a classical codicological analysis, although some conflicting results are obtained. A quantitative and qualitative reconstruction of palettes by means of TXRF- and Raman-spectra, provides with a complimentary and objective tool for distinguishing between scriptoria.

Citation analysis of cuban research. Part 1. A case study: the Cuban Journal of Agricultural Science.

Bibliometric analyses of research in developing countries are interesting for various reasons. The situation of Cuba is rather exceptional. The Cuban Journal of Agricultural Science (CJAS) is the only Cuban research journal, indexed by the Institute of Scientific Informations Web of Science (WoS). We explore the possibilities of a citation analysis for Cuban research publications in general and for those in CJAS in particular. For the period 1988–1999, we find that this journal represents 14% of Cuban research publications, cited in the WoS. We remark that the number of self citations is relatively high and even increases since 1995. The results are classified by disciplines and we use a co-citation matrix to discuss the different observed citation patterns.

Kratzer Potential for Vibrational Levels in Molecular Hydrogen

The vibrational part of the dihydrogen Hamiltonian obeys a quantized Sommerfeld-Kratzer potential, which takes into account internal H2 symmetries. All constants ωe, ke, and re needed for the H2 vibrational system derive from hydrogen mass. Ionic Kratzer bond theory gives covalent bond energy within 0.08% and all levels within 0.02%, which is 30 times better than with a Dunham oscillator and as accurate as early ab initio quantum mechanics.