Dr. rer. nat. Uwe Zscherpel, born in 1961, grew up in Meerane (Saxonia). After school (Abitur 1980) and 18 months military service he studied Physics from 1982 until 1987 (diploma in Experimental Physics) and received his PhD 1993 from the University of Leipzig on Fourier Transform Infrared Spectroscopy of Zeolites. In 1992 he changed to non-destructive testing and from 1996 – 2012 he was head of the working group “Digital Radiology and Image Analysis” at BAM Berlin. Today as Regierungsdirektor his area of expertise is digital image processing in industrial radiology, including NDT film digitization, digital image analysis, pattern recognition and digital reference catalogues for welds and castings. Additional working fields are the characteriszation of all types of radiographic image detectors like NDT film systems, imaging plates and digital detector arrays for industrial applications, standardization and reliability. He is married, has two daughters and one grandson. Phone: +49 30 8104 3677 Address: Division 8.3 Unter den Eichen 87 D-12205 Berlin Germany
Abstract The fundamental and combination vibrations of hydroxyl groups in zeolites (Y, ZSM-5) and... more Abstract The fundamental and combination vibrations of hydroxyl groups in zeolites (Y, ZSM-5) and silicoaluminophosphates (SAPO-5, -17, -34) are investigated. The influence of adsorbed molecules (C 6 F 6 , n-hexane) on the combination vibrations is also studied. Finally, remarks on quantitative evaluation of DRIFT spectra of NaHZSM-5 containing different amounts of bridging OH groups are given.
Vorstellung der Konzepte and Anwendungsbereiche der neuen Norm DIN EN 12681 in 2 Teilen: Film und... more Vorstellung der Konzepte and Anwendungsbereiche der neuen Norm DIN EN 12681 in 2 Teilen: Film und digitale Prufung
Detection and binarization of local objects of interest (defects and abnormalities) in radiograph... more Detection and binarization of local objects of interest (defects and abnormalities) in radiographic images is considered with application to industrial (non-destructive testing) and medical diagnostic imaging. The known standard approaches such as the histogram-based binarization or the method of dynamic thresholding yield poor segmentation results on the images containing small low-contrast objects and noisy background. The proposed method for object detection using binary segmentation has the following advantageous features. A model-based approach is applied which exploits the object multi-scale morphological representation in order to perform a time-effective image analysis. The intensity function is modeled by a polynomial regression representation with the so- called conformable two-region model. The estimation of the model parameters is made by using a robust non-linear estimation procedure. The concept of a multi-scale relevance function has been introduced for rapid location of local objects invariantly to the object shape, size, and orientation. The relevance function is a function that has the local maximum at the location center of an object of interest or its relevant part such as the corner edge. The developed segmentation method has been comparatively tested on radiographic images in non-destructive testing of weld joins and medical images from chest radiography.
The goal of this study was to determine the influence of adsorbed molecules on the OH bending vib... more The goal of this study was to determine the influence of adsorbed molecules on the OH bending vibration, which cannot be directly measured in the fundamental region (750 - 1050 cm-1) because of the strong lattice vibrations of the substrate. The only way is to measure the combination vibrations in the near infrared. The Diffuse Reflectance Infrared Fourier Transform (DRIFT) technique was used to study the whole spectral range from the fundamental vibrations of OH groups to the overtones in the near infrared (3000 - 7500 cm-1) on the same sample. Several OH groups with different acidity on silica and crystalline alumosilica (zeolites) have been investigated.
By using an IR diffuse reflectance technique it is possible to simplify various kinds of powder m... more By using an IR diffuse reflectance technique it is possible to simplify various kinds of powder measurements, thus eliminating traditional sample preparation steps of grinding and pellet pressing. In addition, various experimental in situ arrangements can be realized more easily than in the corresponding transmission arrangement. The DRIFT technique has a great advantage for detecting weak absorption bands compared with common IR transmission. This work aims to demonstrate the advantage of DRIFT measurements to solve various chemical problems.
While the absorption of X-rays and gamma radiation is determined by the Z-number of the elements ... more While the absorption of X-rays and gamma radiation is determined by the Z-number of the elements a specimen is composed of, it is the hydrogen making an effective contrast with neutron imaging. As a consequence, interrogating with neutrons presents a suitable tool to study the distribution of organic consolidants in materials such as wood as encountered in impregnated wooden artworks. Four different examples of objects are presented here to demonstrate the potential of neutron CT: 1) small wooden pieces of ship wrecks (< 2 cm thickness) interrogated with cold neutrons (0.5 meV at the ANTARES facility of the FRM II in Garching) to demonstrate the potential and the limitation of using low energy neutrons, 2) a wooden statue soaked with carbolineum (fission neutrons 1.8 MeV at the NECTAR facility of the FRM II), 3) a smaller wooden figure of a skull heavily soaked with carbolineum so it was too tight for the fission neutrons used before with accelerator neutrons (broad range about 5...
The direct detection of X-ray photons into electrical signals is enabled by usage of highly absor... more The direct detection of X-ray photons into electrical signals is enabled by usage of highly absorbing photo conducting materials (e.g. CdTe) as detection layer of an underlying CMOS semiconductor X-ray image detector. If the read-out speed is high enough (ca. 50 - 100 ns dead time) single X-ray photons can be counted and their energy measured. Read-out noise and dark image correction can be diminished. By setting energy thresholds, selected energy ranges of the X-ray spectrum can be detected or suppressed. This allows material discrimination or reduction of scattered radiation, which results in an enhanced contrast sensitivity.
Throughout human history, wood has been used for various purposes: for building shelters, houses ... more Throughout human history, wood has been used for various purposes: for building shelters, houses and bridges, for manufacturing furniture and household or agricultural appliances (from ploughs to spoons), as burning material or simply as walking sticks. Contemporarily, vast amounts of wood are going into paper production. As a consequence, different qualities of wood are selected appropriately for the various applications. Beams incorporated into buildings and constructions have to be sturdy and durable; boards for furniture are supposed to be free of knots or are expected to have certain ornamental structures. As long as wood is not simply destined for burning it should be free of undesired knots or internal damages such as rot or worm holes. Particularly in cases of infestation with wood destroying fungi that definitely impairs mechanical strength and even may generate hollows such damages are frequently invisible from the outside. Radiographic methods are capable to detect internal damages as well as hidden knots without the need of drilling holes or cutting a specimen to pieces. The most thoroughly method to visualise the interior of a wooden specimen is tomography which shows annual growth rings in their complete circumference and all the knots or damages that might be included. However, some of them as well as patterns of annual rings suitable for dendrological investigations are recognisable with a less laborious method that might be applicable even in the field, i.e. contemporary digital radiography combined with image processing. Samples of lumber shall be presented showing the typical annual ring structures and some infested areas.
Presentation of the final compromise reached in 2018 for revision of ISO 24497, final draft for v... more Presentation of the final compromise reached in 2018 for revision of ISO 24497, final draft for voting at ISO can be prepared now.
Abstract The fundamental and combination vibrations of hydroxyl groups in zeolites (Y, ZSM-5) and... more Abstract The fundamental and combination vibrations of hydroxyl groups in zeolites (Y, ZSM-5) and silicoaluminophosphates (SAPO-5, -17, -34) are investigated. The influence of adsorbed molecules (C 6 F 6 , n-hexane) on the combination vibrations is also studied. Finally, remarks on quantitative evaluation of DRIFT spectra of NaHZSM-5 containing different amounts of bridging OH groups are given.
Vorstellung der Konzepte and Anwendungsbereiche der neuen Norm DIN EN 12681 in 2 Teilen: Film und... more Vorstellung der Konzepte and Anwendungsbereiche der neuen Norm DIN EN 12681 in 2 Teilen: Film und digitale Prufung
Detection and binarization of local objects of interest (defects and abnormalities) in radiograph... more Detection and binarization of local objects of interest (defects and abnormalities) in radiographic images is considered with application to industrial (non-destructive testing) and medical diagnostic imaging. The known standard approaches such as the histogram-based binarization or the method of dynamic thresholding yield poor segmentation results on the images containing small low-contrast objects and noisy background. The proposed method for object detection using binary segmentation has the following advantageous features. A model-based approach is applied which exploits the object multi-scale morphological representation in order to perform a time-effective image analysis. The intensity function is modeled by a polynomial regression representation with the so- called conformable two-region model. The estimation of the model parameters is made by using a robust non-linear estimation procedure. The concept of a multi-scale relevance function has been introduced for rapid location of local objects invariantly to the object shape, size, and orientation. The relevance function is a function that has the local maximum at the location center of an object of interest or its relevant part such as the corner edge. The developed segmentation method has been comparatively tested on radiographic images in non-destructive testing of weld joins and medical images from chest radiography.
The goal of this study was to determine the influence of adsorbed molecules on the OH bending vib... more The goal of this study was to determine the influence of adsorbed molecules on the OH bending vibration, which cannot be directly measured in the fundamental region (750 - 1050 cm-1) because of the strong lattice vibrations of the substrate. The only way is to measure the combination vibrations in the near infrared. The Diffuse Reflectance Infrared Fourier Transform (DRIFT) technique was used to study the whole spectral range from the fundamental vibrations of OH groups to the overtones in the near infrared (3000 - 7500 cm-1) on the same sample. Several OH groups with different acidity on silica and crystalline alumosilica (zeolites) have been investigated.
By using an IR diffuse reflectance technique it is possible to simplify various kinds of powder m... more By using an IR diffuse reflectance technique it is possible to simplify various kinds of powder measurements, thus eliminating traditional sample preparation steps of grinding and pellet pressing. In addition, various experimental in situ arrangements can be realized more easily than in the corresponding transmission arrangement. The DRIFT technique has a great advantage for detecting weak absorption bands compared with common IR transmission. This work aims to demonstrate the advantage of DRIFT measurements to solve various chemical problems.
While the absorption of X-rays and gamma radiation is determined by the Z-number of the elements ... more While the absorption of X-rays and gamma radiation is determined by the Z-number of the elements a specimen is composed of, it is the hydrogen making an effective contrast with neutron imaging. As a consequence, interrogating with neutrons presents a suitable tool to study the distribution of organic consolidants in materials such as wood as encountered in impregnated wooden artworks. Four different examples of objects are presented here to demonstrate the potential of neutron CT: 1) small wooden pieces of ship wrecks (< 2 cm thickness) interrogated with cold neutrons (0.5 meV at the ANTARES facility of the FRM II in Garching) to demonstrate the potential and the limitation of using low energy neutrons, 2) a wooden statue soaked with carbolineum (fission neutrons 1.8 MeV at the NECTAR facility of the FRM II), 3) a smaller wooden figure of a skull heavily soaked with carbolineum so it was too tight for the fission neutrons used before with accelerator neutrons (broad range about 5...
The direct detection of X-ray photons into electrical signals is enabled by usage of highly absor... more The direct detection of X-ray photons into electrical signals is enabled by usage of highly absorbing photo conducting materials (e.g. CdTe) as detection layer of an underlying CMOS semiconductor X-ray image detector. If the read-out speed is high enough (ca. 50 - 100 ns dead time) single X-ray photons can be counted and their energy measured. Read-out noise and dark image correction can be diminished. By setting energy thresholds, selected energy ranges of the X-ray spectrum can be detected or suppressed. This allows material discrimination or reduction of scattered radiation, which results in an enhanced contrast sensitivity.
Throughout human history, wood has been used for various purposes: for building shelters, houses ... more Throughout human history, wood has been used for various purposes: for building shelters, houses and bridges, for manufacturing furniture and household or agricultural appliances (from ploughs to spoons), as burning material or simply as walking sticks. Contemporarily, vast amounts of wood are going into paper production. As a consequence, different qualities of wood are selected appropriately for the various applications. Beams incorporated into buildings and constructions have to be sturdy and durable; boards for furniture are supposed to be free of knots or are expected to have certain ornamental structures. As long as wood is not simply destined for burning it should be free of undesired knots or internal damages such as rot or worm holes. Particularly in cases of infestation with wood destroying fungi that definitely impairs mechanical strength and even may generate hollows such damages are frequently invisible from the outside. Radiographic methods are capable to detect internal damages as well as hidden knots without the need of drilling holes or cutting a specimen to pieces. The most thoroughly method to visualise the interior of a wooden specimen is tomography which shows annual growth rings in their complete circumference and all the knots or damages that might be included. However, some of them as well as patterns of annual rings suitable for dendrological investigations are recognisable with a less laborious method that might be applicable even in the field, i.e. contemporary digital radiography combined with image processing. Samples of lumber shall be presented showing the typical annual ring structures and some infested areas.
Presentation of the final compromise reached in 2018 for revision of ISO 24497, final draft for v... more Presentation of the final compromise reached in 2018 for revision of ISO 24497, final draft for voting at ISO can be prepared now.
Uploads
Papers by Uwe Zscherpel