177,830 research outputs found
Giant hyracoid from basal Middle Miocene deposits at Gebel Zelten, Libya
No full textPrevious records of the presence of the hyracoid Prohyrax sp. at Gebel Zelten are unsubstantiated and the original material seems to have been lost. A distal metapodial of a large hyracoid collected by R. Savage at locality W, Gebel Zelten, is similar in morphology and dimensions to a fossil from Nova, South Africa provisionally attributed to Parapliohyrax. Large hyracoids were thus present in Libya during the early part of the Middle Miocene.Los registros previos de la presencia del hyracoideo Prohyrax sp. en Gebel Zelten son insuficientes y el material original parece haberse perdido. Un fragmento distal de metápodo de un gran hyracoideo recolectado por R. Savage en la localidad W, Gebel Zelten es similar en morfología y dimensiones al fósil de Nova, Sudáfrica provisionalmente atribuidos a Parapliohyrax. Los grandes hyracoideos estuvieron presentes en Libia durante la primera parte del Mioceno Medio
New suoid specimens from Gebel Zelten, Libya
No full textA restricted collection of suoids from Gebel Zelten was made in the 1990’s by the Spanish-Libyan Palaeontology Expedition. Dr Dolores Soria filmed the specimens with a video camera and took measurements of the teeth with vernier calipers. This paper uses the images from the video, which, even though somewhat limited in terms of picture quality, are of interest because they represent the first known snout of the gigantic suid Megalochoerus khinzikebirus. The images reveal that it is basically an enlarged version of Libycochoerus massai, but with relatively small premolars. The sanithere specimens from the site were photographed with an Olympus 1.4 megapixel digital camera, and the image quality is better than from the video camera. These specimens throw light on the degree of sexual dimorphism exhibited by sanitheres, a feature that was previously inferred from isolated teeth, but which can now be confirmed on the basis of the two mandible fragments from Gebel Zelten. This paper is dedicated to the memory of Dr Soria. This paper takes into account a few undescribed suid post-cranial bones from Gebel Zelten housed in the Natural History Museum, London, collected during the 1960’s by R. Savage.Una limitada colección de suoideos procedentes de Gebel Zelten fue hecha a finales de los años 1990 por una expedición paleontológica internacional, con participación española y libia. La Dra. Dolores Soria filmó los ejemplares con una cámara de vídeo y tomó las medidas de los dientes con calibre. En este trabajo se utilizan las imágenes filmadas, que, aunque algo limitadas en términos de calidad fotográfica, son interesantes porque representan las primeras conocidas del rostro del suido gigante Megalochoerus khinzikebirus. Las imágenes revelan que básicamente es una versión agrandada de Libycochoerus massai, pero con premolares relativamente más pequeños. Los ejemplares de saniterios fueron fotografiados con una cámara digital Olympus de 1,4 megapixeles, y la calidad de las imágenes son mejores que las de la cámara de vídeo. Estos ejemplares arrojan nueva luz sobre el grado de dimorfismo sexual exhibido por los saniterios, un hecho que había sido previamente inferido sólo a partir de dientes aislados, pero que ahora puede ser confirmado en base a dos fragmentos de mandíbula de Gebel Zelten. Este trabajo está dedicado a la memoria de la Dra. Soria. En este trabajo se consideran algunos huesos postcraneales inéditos procedentes de Gebel Zelten, depositados en el Natural History Museum de Londres y recolectados durante los años 1960 por R. Savage
Gebel Adda Cemeteries 3 and 4 (1963-1964)
No full textThe excavation team of the American Research Center in
Egypt, under the direction of Dr Nicholas B. Millet, first
arrived at Gebel Adda in January 1963, for what were to
be four excavation seasons. Excavations started in Cemetery
1, which included numerous tumuli, extending over
c. 450m from the southern end of the concession to north
east of the Citadel (Millet 1963). Work began in the south
of the cemetery and excavated c. 127 tumuli, dated to the
later post-Meroitic (X-Group) period. In the same area,
amongst the tumuli, c. 30 medieval (Christian) graves were
also found, thought likely to date to the earliest period
of Christianization at Gebel Adda. Four examples of the
double domed mud-brick tombs of the post-medieval
(Islamic) period were also excavated in Cemetery One.
In March 1963 excavations were also begun in Cemetery
3, lying some 160m south east of the Citadel hill (Figure
1, Plate 1), an area covered with much wind-blown sand,
exposing c. 400 tombs during the first season (Millet 1963,
154). This work was continued in the second (1963-1964)
season (Millet 1964) and the third season, for which no
preliminary report was published (see also Millet 1967b;
1968; 2005; Grzymski 2010).
Some preliminary observations of this area were published
as the excavations were still underway by Millet (Millet 1963;
1964), but little else relating to this important work has yet
been published. However, the first author (RH), as a member
of the ARCE team, can throw some further light on some features of the excavations. Most importantly, having carried
out much of the original preparation of site plans, it has been
possible to reconstruct here some partial plans of Cemetery
3, which together with personal photographs of the site
provide some useful new information concerning this part of
the Gebel Adda excavations. Until the surviving site archives
are more fully studied, and hopefully published, this brief
report, as with previous reports (Huber and Edwards 2009;
2010), can provide a few further insights into the fascinating
and clearly complex history of the Gebel Adda cemeteries
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Zwei Bemerkungen zu Gebel es-Silsila Nr. 100
No full textThe stela of Shoshenq I at Gebel es-Silsila contains a verb mtj thai has beeil considered as an early example of mtj/mtr, 'to be pleased' (attested mainly in demotic). This paper tries to show that it belongs to the stem mtn/mtn, 'to reward'. A writing of the Infinitive o f / r / o n this same stela a&jr.rin is attested several times at the beginning of
the Twenty-second Dynasty
Hygrothermal aging of Nafion (R)
No full textCollette, Floraine M. Lorentz, Chantal Gebel, Gerard Thominette, FrancetteThe membrane durability is a critical issue for the development of Proton Exchange Membrane Fuel Cells (PEMFC). Since PEMFC in situ tests were not conclusive to determine Nafion (R) membrane degradation mechanism, ex situ aging tests were performed on Nafion (R) 112 in practical fuel cell usage conditions. The polymer chemical structure evolution was investigated by infrared spectroscopy (IR) and Nuclear Magnetic Resonance (NMR) while its hydrophilicity, directly linked to its protonic conductivity, is established through sorption isotherms by Dynamical Vapour Sorption (DVS). Durability studies over a period of 400 days revealed membrane degradation through a modification of sulfonic acid end-groups. Formation of sulfonic anhydride (from the condensation of sulfonic acids) was strongly demonstrated by IR spectroscopy and, indirectly, by NMR. The substitution of ionic end-groups by less hydrophilic anhydrides leads to a significant decrease of water uptake and thus of its hydrophilicity. Surprisingly, kinetic study reveals that the hygrometric level accelerates this condensation reaction. (C) 2009 Elsevier B.V. All rights reserved
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
New perspectives on the agricultural development of gebel and pre-desert in Roman Tripolitania.
No full textMattingly David J. New perspectives on the agricultural development of gebel and pre-desert in Roman Tripolitania.. In: Revue de l'Occident musulman et de la Méditerranée, n°41-42, 1986. Désert et montagne au Maghreb, sous la direction de P.-R. Baduel. pp. 45-65
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
H.G. Gebel and S.K. Kozlowski (eds), 1994. - Neolithic chipped stone industries of the Fertile Crescent. Studies in Early Near Estem Production, Subsistence and Environment I.
No full textValla F. R. H.G. Gebel and S.K. Kozlowski (eds), 1994. - Neolithic chipped stone industries of the Fertile Crescent. Studies in Early Near Estem Production, Subsistence and Environment I.. In: Paléorient, 1996, vol. 22, n°2. pp. 143-145
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