Radovan Despot

Upgrading of spruce wood with ethanolamine treatment

Wood is the most abundant non-toxic, recycable and biodegradable natural material, valued as a construction material because of its appearance and its high strength at low density. On the other hand its biodegradability is an important drawback. Improvement of decay resistance of wood with ethanolamine is described in this paper. Ethanolamine chemically reacts with wood (Norway spruce sapwood) and does not evaporate from it. During this reaction, significant amounts of oxygen are consumed. Upgraded specimens show increased fungal activity and increased combustibility. The treatment of the spruce wood samples with aqueous solutions of ethanolamine resulted in colour changes.

Changes in physical, mechanical and chemical properties of wood during sterilisation by gamma radiation

Abstract Gamma irradiation, which is an easy, fast and effective method for wood sterilisation, changes molecular structures not only in pest cells, but also in wood cell walls. Radiation-induced depolymerisation causes significant changes in some properties of wood crucial for restoration and for laboratory testing of wood-preservative effectiveness, as demonstrated by experimental data. The influence of gamma radiation on maximum swelling (αMAX), resistance to impact milling (RIM), and the total amount of water-soluble carbohydrates (TSC) was investigated. Cobalt (60Co) was used as a gamma source and Scots pine wood (Pinus sylvestris L.) was irradiated at doses of 30, 90 and 150 kGy. A strong linear correlation was found between TSC and radiation dosage. Leached irradiated specimens showed significantly greater TSC content than non-irradiated controls. RIM decreased significantly and linearly with increasing radiation dosage. After leaching, the linearity between these parameters improved. Gamma radiation had no significant effect on αMAX and the time elapsed after irradiation did not influence αMAX, RIM or TSC.

Scenes from the Past: CT-guided Endoscopic Recovery of a Foreign Object from the Cranial Cavity of an Ancient Egyptian Mummy

The aim of this study was to test the value of computed tomography (CT)-guided endoscopy in the scientific study of mummified remains and the recovery of unidentified objects from ancient mummified remains. CT-guided endoscopy was performed on an Egyptian mummy from the Late Period to help retrieve an unidentified object from its skull. The combined use of CT and endoscopy facilitated the recovery of the object, minimizing further damage to the remains and to the object itself. The successful recovery of the brittle object allowed detailed analysis of the item to be performed in an attempt to determine the nature of its presence in the cranial cavity. It was confirmed that the object was a monocotyledon stem fragment. Relying on the existing literature on mummification and excerebration methods in ancient Egypt, we concluded that the stick was probably used for transnasal removal of the brain. The results of this study demonstrate the great potential of CT-guided endoscopy for minimally invasive recovery of small unidentified items from mummies that could yield important information about mummification procedures and the materials used to preserve bodies.

Changes in Selected Properties of Wood Caused by Gamma Radiation

Gamma radiation – as an easy, fast, and effective sterilisation method – changes molecular structures not only in pest’s living cells, but also in wooden cell walls. Radiation-induced depolymerisation causes significant changes in some properties of wood crucial for restoration and for laboratory testing the resistance of wood and wooden products against wood-destroying organisms. Overview of up to date data on the influence of gamma radiation onto some physical, mechanical and chemical properties and on biological resistance against fungal decay are presented.

The Echo (Jeka) Pavilion in Forest-Park Maksimir Zagreb - Restoration and Health Monitoring

The wooden pavilion Jeka (Echo) was built in 1843 according to the plans of the Austrian Empire garden architect Franz Schücht. Echo pavilion is the only remaining one of ten similar pavilions that were placed in the Forest-park Maksimir during the 19th century. Since 1964 the Echo pavilion has been protected by law and declared as cultural monument of garden architecture together with the whole park Maksimir, in which it is situated. Although the pavilion was restored several times (last time in 1986) it was in very bad condition. The reconstruction and preservation of the complete pavilions wooden construction were done after a careful analysis of its recent state in 2000. Restoration of the “Echo” Pavilion was started because its construction was in poor condition and because the whole pavilion was unsafe. There was a severe decay of the lower parts of the poles, particularly those faced to the North. New poles or only the new parts of the poles were made of glued spruce core surrounded by larch heartwood. Organic solvent Tebuconazole and WOODCAP products were used in wood preservation. The restoration of the Pavilion can be seen as an attempt to extend the life time of a severely damaged cultural monument, or at least in those parts of the monument where the amendments were possible. During reconstruction a monitoring system for wood moisture content at three different positions inside the roof construction was installed. Twice a year the pavilion is being carefully visually inspected and data from data logger downloaded and correctness of the equipment verified.This example of the “Echo” Pavilion is showing that moisture monitoring systems can considerably contribute to prevent cultural heritage from decay. The installed inexpensive and simple monitoring system of early warning proved to be feasible and saved costs in the conservation of wooden cultural heritage. In times of tight budgets and increasing rates of decay moisture monitoring systems will become increasingly important.