Andreas Burmester | Technical University of Munich (original) (raw)
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Papers by Andreas Burmester
Phosphorus and Sulfur and the Related Elements, 1980
Das Fluoratom in 2,2-Diphenyl-2-fluor-2,3-dihydro-1,3,2-benzoxazaphospholen A ist sehr reaktiv, s... more Das Fluoratom in 2,2-Diphenyl-2-fluor-2,3-dihydro-1,3,2-benzoxazaphospholen A ist sehr reaktiv, so daß verschiedene nucleophile Reaktionen mit guten Ausbeuten möglich sind. Bei Einwirkung metallorganischer Verbindungen entstehen 2,2,2-Triorganyl-dihydrophosphole bzw. die entsprechenden (o-Hydroxyphenyl)-iminophosphorane. Durch Umsetzung mit Natriumalkoholaten kann in glatter Reaktion das Fluor gegen eine Alkoxygruppe ausgetauscht werden. Die so dargestellten p-Alkoxydihydro-benzoxazaphosphole lassen sich zu den durch Ringöffnung entstehenden entsprechenden Iminophosphoranyl-phenoxylen oxidieren. Die Strukturen der neu dargestellten Verbindungen werden insbesondere durch NMR- (H, P, N) und ESR-Spektren gesichert.The reactivity of the fluoro atom in the 2,2-diphenyl-2-fluoro-2,3-dihydro-1,3,2-benzoxazaphospholes A permits several nucleophilic reactions. The yields of the products obtained are generally good. Addition of metalorganic compounds to A leads to (o-hydroxyphenyl)-iminophosphoranes. In the reaction of A with sodium alcoholates an exchange of the fluoro atom by an alkoxy group takes place. Oxydation of these p-alkoxy-dihydro-benzoxazaphospholes proceeds under ring opening to the corresponding iminophosphoranyl phenoxyles. The structures of the new compounds are investigated mainly by nmr (H, P, N) and esr spectroscopy.
Recording Systems: High-Resolution Cameras and Recording Devices and Laser Scanning and Recording Systems, 1993
ABSTRACT This paper proposes a new approach to monitor the condition of a painting. That is the a... more ABSTRACT This paper proposes a new approach to monitor the condition of a painting. That is the acquisition of the surface structure of the painting. As transportation damages are known to affect the crack pattern, very detailed images (cracks < 0.1 mm) are required. A compromise between this requirement and today's feasibility consists in using resolutions of about 20 pixel/mm with 8 bit, meaning images of 20k X 20k for a painting of 1 m X 1 m. A Kontron ProgRes 3000 on a high precision 3D motorized frame (repositioning accuracy < 0.01 mm) is used for the acquisitions before and after transportation. Each pair of images is resampled to compensate for geometrical distortions. The crack network is then detected by using line detection algorithms derived from mathematical morphology. The images are finally superimposed and changes can be detected manually or automatically. While the main focus of this contribution is spent on technical details, case studies are used to discuss recent applications.
Studies in Conservation, 1998
ABSTRACT The pigments used in 13 paintings by Albrecht Dürer have been identified: azurite, ultra... more ABSTRACT The pigments used in 13 paintings by Albrecht Dürer have been identified: azurite, ultramarine, verdigris, lead-tin yellow, brown and, occasionally, yellow ochres, cinnabar, red lead, red lakes, basic lead white as well as plant and bone black. Dürer mentions only four of these in his diaries and letters, and, except for ultramarine, there are no indications of where he obtained his pigments. Mediaeval documentary sources indicate that artists' pigments were available from pharmacies. Examination of fifteenth/sixteenth-century pharmacy price lists shows that all the pigments Dürer used were available. The composition of the palette depended to a certain degree on the cost of the pigments. This is exemplified by the blues, and we focus on Dürer's use of azurite and ultramarine. The nomenclature, origin, production and trade in azurite in late mediaeval times are discussed in more detail.
Studies in Conservation, 2000
Close Document Image Close Document Printer Image Print This Document! Conservation Information N... more Close Document Image Close Document Printer Image Print This Document! Conservation Information Network (BCIN). Author: Feller, Robert L. Editor: Feller, Robert L. Roy, Ashok FitzHugh, Elisabeth West Berrie, Barbara Hepburn ...
Chemische Berichte, 1981
Zahlreiche am Phosphor unterschiedlich substituiene 1,3,2-Benzoxazaphospholine (8 -11, 16 -28, s.... more Zahlreiche am Phosphor unterschiedlich substituiene 1,3,2-Benzoxazaphospholine (8 -11, 16 -28, s. Tab. 1) zeigen im Bereich der 31P-NMR-Absorption des pentavalenten Phosphors zwei Signale.
Chemische Berichte, 1981
Die Synthese zahlreicher (AlkyI-2-hydroxyphenylimino)phosphorane wird beschrieben. Fur das bei di... more Die Synthese zahlreicher (AlkyI-2-hydroxyphenylimino)phosphorane wird beschrieben. Fur das bei diesen Verbindungen zu beobachtende und friiher diskutierte Gleichgewicht zwischen zwei tautomeren Formen A und B konnen durch ' H-NMR-Untersuchungen die Aktivierungsparameter bestimmt werden. Die Lebensdauern von A und B liegen bei 298 K zwischen 0.1 und 10 s.
In recent years digital imaging has proved to be a useful tool for documenting and examining pain... more In recent years digital imaging has proved to be a useful tool for documenting and examining paintings. These techniques can yield permanent records that are potentially more accurate than photographic images. The key applications in which digital imaging is superior to other techniques are those where short- or long-term changes are measured. The paper describes the imaging systems developed in a ten-year collaboration between the National Gallery, London and the Doerner-Institut, Munich and the geometric transformation algorithms which have allowed accurate comparisons of ‘before’ and ‘after’ images to be made. Recent results obtained from a long-term study of colour changes caused by display in the museum and short-term changes caused by transportation to loan exhibitions are presented. Improvements made to the procedure for acquiring, processing and presenting infrared reflectogram mosaics are also detailed. Finally, other conservation-related and archival uses for the colour-accurate, high-resolution digital images are discussed.
Phosphorus and Sulfur and the Related Elements, 1980
Das Fluoratom in 2,2-Diphenyl-2-fluor-2,3-dihydro-1,3,2-benzoxazaphospholen A ist sehr reaktiv, s... more Das Fluoratom in 2,2-Diphenyl-2-fluor-2,3-dihydro-1,3,2-benzoxazaphospholen A ist sehr reaktiv, so daß verschiedene nucleophile Reaktionen mit guten Ausbeuten möglich sind. Bei Einwirkung metallorganischer Verbindungen entstehen 2,2,2-Triorganyl-dihydrophosphole bzw. die entsprechenden (o-Hydroxyphenyl)-iminophosphorane. Durch Umsetzung mit Natriumalkoholaten kann in glatter Reaktion das Fluor gegen eine Alkoxygruppe ausgetauscht werden. Die so dargestellten p-Alkoxydihydro-benzoxazaphosphole lassen sich zu den durch Ringöffnung entstehenden entsprechenden Iminophosphoranyl-phenoxylen oxidieren. Die Strukturen der neu dargestellten Verbindungen werden insbesondere durch NMR- (H, P, N) und ESR-Spektren gesichert.The reactivity of the fluoro atom in the 2,2-diphenyl-2-fluoro-2,3-dihydro-1,3,2-benzoxazaphospholes A permits several nucleophilic reactions. The yields of the products obtained are generally good. Addition of metalorganic compounds to A leads to (o-hydroxyphenyl)-iminophosphoranes. In the reaction of A with sodium alcoholates an exchange of the fluoro atom by an alkoxy group takes place. Oxydation of these p-alkoxy-dihydro-benzoxazaphospholes proceeds under ring opening to the corresponding iminophosphoranyl phenoxyles. The structures of the new compounds are investigated mainly by nmr (H, P, N) and esr spectroscopy.
Recording Systems: High-Resolution Cameras and Recording Devices and Laser Scanning and Recording Systems, 1993
ABSTRACT This paper proposes a new approach to monitor the condition of a painting. That is the a... more ABSTRACT This paper proposes a new approach to monitor the condition of a painting. That is the acquisition of the surface structure of the painting. As transportation damages are known to affect the crack pattern, very detailed images (cracks < 0.1 mm) are required. A compromise between this requirement and today's feasibility consists in using resolutions of about 20 pixel/mm with 8 bit, meaning images of 20k X 20k for a painting of 1 m X 1 m. A Kontron ProgRes 3000 on a high precision 3D motorized frame (repositioning accuracy < 0.01 mm) is used for the acquisitions before and after transportation. Each pair of images is resampled to compensate for geometrical distortions. The crack network is then detected by using line detection algorithms derived from mathematical morphology. The images are finally superimposed and changes can be detected manually or automatically. While the main focus of this contribution is spent on technical details, case studies are used to discuss recent applications.
Studies in Conservation, 1998
ABSTRACT The pigments used in 13 paintings by Albrecht Dürer have been identified: azurite, ultra... more ABSTRACT The pigments used in 13 paintings by Albrecht Dürer have been identified: azurite, ultramarine, verdigris, lead-tin yellow, brown and, occasionally, yellow ochres, cinnabar, red lead, red lakes, basic lead white as well as plant and bone black. Dürer mentions only four of these in his diaries and letters, and, except for ultramarine, there are no indications of where he obtained his pigments. Mediaeval documentary sources indicate that artists' pigments were available from pharmacies. Examination of fifteenth/sixteenth-century pharmacy price lists shows that all the pigments Dürer used were available. The composition of the palette depended to a certain degree on the cost of the pigments. This is exemplified by the blues, and we focus on Dürer's use of azurite and ultramarine. The nomenclature, origin, production and trade in azurite in late mediaeval times are discussed in more detail.
Studies in Conservation, 2000
Close Document Image Close Document Printer Image Print This Document! Conservation Information N... more Close Document Image Close Document Printer Image Print This Document! Conservation Information Network (BCIN). Author: Feller, Robert L. Editor: Feller, Robert L. Roy, Ashok FitzHugh, Elisabeth West Berrie, Barbara Hepburn ...
Chemische Berichte, 1981
Zahlreiche am Phosphor unterschiedlich substituiene 1,3,2-Benzoxazaphospholine (8 -11, 16 -28, s.... more Zahlreiche am Phosphor unterschiedlich substituiene 1,3,2-Benzoxazaphospholine (8 -11, 16 -28, s. Tab. 1) zeigen im Bereich der 31P-NMR-Absorption des pentavalenten Phosphors zwei Signale.
Chemische Berichte, 1981
Die Synthese zahlreicher (AlkyI-2-hydroxyphenylimino)phosphorane wird beschrieben. Fur das bei di... more Die Synthese zahlreicher (AlkyI-2-hydroxyphenylimino)phosphorane wird beschrieben. Fur das bei diesen Verbindungen zu beobachtende und friiher diskutierte Gleichgewicht zwischen zwei tautomeren Formen A und B konnen durch ' H-NMR-Untersuchungen die Aktivierungsparameter bestimmt werden. Die Lebensdauern von A und B liegen bei 298 K zwischen 0.1 und 10 s.
In recent years digital imaging has proved to be a useful tool for documenting and examining pain... more In recent years digital imaging has proved to be a useful tool for documenting and examining paintings. These techniques can yield permanent records that are potentially more accurate than photographic images. The key applications in which digital imaging is superior to other techniques are those where short- or long-term changes are measured. The paper describes the imaging systems developed in a ten-year collaboration between the National Gallery, London and the Doerner-Institut, Munich and the geometric transformation algorithms which have allowed accurate comparisons of ‘before’ and ‘after’ images to be made. Recent results obtained from a long-term study of colour changes caused by display in the museum and short-term changes caused by transportation to loan exhibitions are presented. Improvements made to the procedure for acquiring, processing and presenting infrared reflectogram mosaics are also detailed. Finally, other conservation-related and archival uses for the colour-accurate, high-resolution digital images are discussed.