Ursula Baumer - Academia.edu (original) (raw)

Papers by Ursula Baumer

Studies in Conservation, 2006

European Journal of Archaeology, 2001

Any new knowledge that goes beyond the stone tools and techniques used in the Palaeolithic and Me... more Any new knowledge that goes beyond the stone tools and techniques used in the Palaeolithic and Mesolithic is most significant as it reveals the cultural and technical capabilities of the people living in these periods. In 1963, two pitch finds were discovered in a lignite open-mining pit in the northern foothills of the Harz Mountains, in a layer the geological age of which was dated as being older than 80,000 years. The great significance of these finds was therefore immediately apparent. One of the finds showed a fingerprint as well as the imprints of a flint stone tool and the structure of wood cells. This was indicative of the pitch piece having served as an adhesive to secure a wooden haft to a flint stone blade.Over 30 years later these finds were transferred to the Doerner Institut for investigation. The GC and GC/MS analyses revealed that, in both cases, birch pitches, well-known historical adhesives, had been used. These consist predominantly of pentacyclic triterpenoid components of the lupane type, with betulin forming the major component. The comparison with birch bark extracts showed that the biological peak profile (bio-marker) was surprisingly well preserved in these pitch finds and that hardly any degradation products were present.Today, comparable pitches can easily be produced with modern technical methods, i.e. using airtight laboratory flasks and temperature control facilities. However, any attempt at simulating the conditions of the Neandertal period and at producing these birch pitches without any of these modern facilities will soon be met with many difficulties. This implies that the Neandertals did not come across these pitches by accident but must have produced them with intent. Conscious action is, however, always a clear sign of considerable technical capabilities.

ICOMOS – Hefte des Deutschen Nationalkomitees, Jun 22, 2015

Zeitschrift für Naturforschung B, May 1, 2003

Zeitschrift für Naturforschung C, Aug 1, 1994

Archaeometry, Aug 1, 2005

Analytical Chemistry, Aug 1, 1998

Nature, 1998

Our knowledge of the conservation techniques used in the Old Kingdom of ancient Egypt is limited.... more Our knowledge of the conservation techniques used in the Old Kingdom of ancient Egypt is limited. Examinations of a clavicle fragment of the mummy of Idu II, secretary general of the pine wood trade office (2150 plusminus 50 BC), revealed saturation with a wealth of ...

Deutscher Kunstverlag eBooks, 2016

Dans cet article sont presentes les resultats d'analyses recentes effectuees sur deux fragmen... more Dans cet article sont presentes les resultats d'analyses recentes effectuees sur deux fragments de resine decouverts en 1963 et 1964 lors de fouilles de sauvetages dans une mine de lignite pres de Kοnigsaue. Si de nouvelles datations C14 ont confirme l'origine prehistorique de ces fragments (Paleolithique moyen), la nature de leur composition a pu etre egalement determinee. Il s'agit dans les deux cas de poix fabriquee a partir d'ecorce de bouleau.

Wernersche Verlagsgesellschaft, Nov 23, 2020

No abstract available

Zeitschrift für Naturforschung. C. A journal of biosciences, 1994

Schon 1998 am Rheinischen Landesmuseum Bonn und der Antikensammlung Berlin durchgeführte Forschun... more Schon 1998 am Rheinischen Landesmuseum Bonn und der Antikensammlung Berlin durchgeführte Forschungen zur Herstellungstechnik römischer Reiterhelmmasken aus Neuss, Köln und Dormagen warfen Fragen nach der Montage von Überzügen aus Metall, wie Silber oder Kupferlegierungen, an römischen Reiterhelmen auf. Im Zuge eines weiteren Forschungsprojektes zur Reiterhelmmaske aus Kalkriese konnte nun erstmals eine Möglichkeit der Montage nachgewiesen werden. Hierbei handelt es sich um eine organische Metallklebemasse, die an einem römischen Prunkhelm des 1. Jh. n. Chr. analytisch nachgewiesen werden konnte. Der Helm befindet sich im Besitz des LVR-LandesMuseums Bonn und wurde 1986 in den Auskiesungsarealen im Norden der Colonia Ulpia Traiana in Xanten-Wardt bei Ausgrabungen geborgen. Schon bei seiner Restaurierung in den Werkstätten des Bonner Museums stellte sich die Frage nach der Befestigungsmethode des wertvollen Überzugs. Erst durch eine erneute Autopsie des Helms ist es am einem Fragment einer Wangenklappe gelungen eine bislang unbeobachtete Klebemasse zu identifizieren. Die Analyse selbst erfolgte mit Unterstützung des Doerner-Instituts in München.

To better understand the painting technique of a given period, information from different sources... more To better understand the painting technique of a given period, information from different sources are usually combined: written statements by the artist or his contemporaries, art technological study of paintings, and chemical analysis. However, does the information obtained from different sources fit together and form an integral picture? Based on a case study of a painting by Arnold Böcklin this question was evaluated. It was found that the correlation between binding media and the properties of paints manufactured from them is not clear and straight-forward as is usually believed. To understand these correlations, colloid chemistry is indispensable. This paper presents concepts of a colloidal description of paints consisting of pigment, egg and drying oil. Various methods for the preparation of such paints and their resulting properties are discussed considering aspects of colloid chemistry and rheology, such as stability of emulsions, gel formation, interactions between pigment ...