Your search resulted in 8 documents.
Conservation of wooden cultural property
1994 - IRG/WP 94-30038
A survey of the conservation of wooden archtitectual monuments, art objects and archaeological finds is presented. Each of the three areas has typical conservation problems which reqire the use of selected wood preservatives and consolidation agents. Furthermore specific protection and consolidation methods are necessary. A precise damage diagnosis with non-destructive testing methods is the first step in a careful conservation work.
A Unger, W Unger
Analysis of volatile emissions as an aid in the diagnosis of dry rot
1992 - IRG/WP 92-2393
The dry rot fungus, Serpula lacrymans was grown in pure culture on malt extract and on sapwood of pine. The volatile compounds emitted from the cultures were determined by diffusion sampling on tubes filled with Tenax TA, thermal desorption and gas-chromatography-mass-spectrometry in order to find markers for attack of the fungus.
J Bjurman, J Kristensson
Morphological and Molecular Diagnosis of Leptographium spp. in Canadian Softwoods
2003 - IRG/WP 03-10479
Sapstaining fungi that affect commercially important softwood species mainly belong to the genera Ceratocystis, Ophiostoma and Leptographium. Our 1997-1999 fungal surveys confirmed that this is the case in Canada. The work reported here addresses identifying the morphologically plastic Leptographium at the species level, which is difficult using conventional methods. We assessed the morphological and physiological characteristic of survey isolates grown on artificial media and wood, and then compared them with reference cultures. The morphological data obtained from isolates grown on wood were less variable and, therefore, more conclusive, than those grown on artificial media. Microscopic observation of isolates grown on wood, differentiated them into three known Leptographium groups: aureum, clavigerum, and abietinum. Preliminary DNA sequence data for the ITS2 rDNA and β-tubulin genes confirmed the identity of the three species, but also indicated two additional groups. Ongoing biological work and sequencing of other genes will clarify the relationships between these species and discrepancies between morphological and molecular data.
S Alamouti, Jae-Jin Kim, A Uzunovic, C Breuil
rDNA-ITS sequence of Serpula lacrymans and other important indoor rot fungi and taxon-specific priming PCR for their detection
1999 - IRG/WP 99-10298
Taxon-specific priming polymerase chain reaction (TSPP) is a powerful molecular tool for fungal diagnosis. For its application to indoor rot fungi, the internal transcribed spacer (ITS) of the ribosomal DNA (rDNA) of the main fungal species causing wood rot in European buildings was amplified with the polymerase chain reaction (PCR). The ITS region was sequenced. The complete sequences are presented. From base sequence divergency among the fungi, species-specific oligonucleotide primers were designed for TSPP. These marker molecules were suitable for the differential diagnosis of the dry rot fungus, Serpula lacrymans, the wild merulius, S. himantioides, the oak polypore, Donkioporia expansa, the brown cellar fungus, Coniophora puteana, the broad-spored white polypore, Antrodia vaillantii, the sap polypore, Tyromyces placenta, and the yellow-red gill polypore, Gloeophyllum sepiarium. Each specific marker identified isolates of its respective target species. Cross reaction with 'foreign' fungi was the exception. Species identification from unknown field samples from rot damage in buildings is also possible, because DNA from contaminating organisms does not response to the specific primers. Our variant of the technique is fast, because no preceding fungal pure cultures, no special DNA extraction/purification, and no restriction by endonucleases are necessary.
O Schmidt, U Moreth
Diagnosis of failures in wood beams from historical house in Banská Štiavnica – Relations between ultrasonic measurements and bending properties
2010 - IRG/WP 10-20437
Various degrees of rot and other damages in ceiling beams with dimensions of 6500-8800 x 160-200 x 240-310 mm (length x height x width) situated in one historical bourgeois house in the UNESCO town Banská Štiavnica, Slovakia were determined visually and by the PUNDIT-plus ultrasonic device. Subsequently, for seventeen of the most bio-damaged fir (Abies alba Mill.) beams chosen for exchange were carried out other ultrasonic tests and also “in vitro” ultrasonic and bending tests on small specimens (300x20x20 mm). “In situ” measurements have shown that the lowest velocity of ultrasonic waves is usually in the ends of beams, i.e. in their direct contact with walls it was only 300-400 m/s, while 0.5-1 m from their ends it was usually higher from 700 to 1100 m/s. “In vitro” measurements (the modulus of elasticity determined either by ultrasonic test – Ed, or by bending test – E; the bending strength “modulus of rupture” – fm) depended significantly on the density of tested fir specimens. High correlations were observed also between values of the dynamic and static modulus of elasticity, and between values of the modulus of elasticity and values of the bending strength. Achieved “in situ” and “in vitro” results could help at evaluation of bio-damages in other wooden heritage structures, as well.
L Reinprecht, M Pánek
Diagnosis and control of pathology of wood used in the Alahambra Palace, Santiago de Chile
2015 - IRG/WP 15-40711
In 2008, the National Monuments Council, invites bids for the work control termite infestation in the Alhambra Palace, located in Santiago. As part of this service our company decides to make a pathological diagnosis to allow us to make the minimum of damage to the building but maximum control first. The collection of information in the field, the use of advanced technologies and our experience and knowledge, allowed us to successfully perform this purpose because they fail to understand the pathological genesis present, based on which we could implement a program of Integrated Management plague, initially based on proper use of chemicals with different modes of action, but as strategically located within the diagnosis. We accomplished superior control 95% of the pest from 6 months of applying the treatments, which remained until 2014, during the last inspection visit to the Alhambra Palace. Making small interventions focused retreat at the end of 2009 and 2011. To date our companies have made about 50 pathological diagnoses in heritage buildings in Chile, several of which have also performed control treatments successfully in each of the cases. Including the 16 Churches of Chiloé declared World Heritage Site.
J Poblete Escanilla, P Astaburuaga Merino
Evaluation of timber bridges with special consideration of detail design
2017 - IRG/WP 17-40781
Since 1997 the use of wood in bridge construction has been increasingly criticized by the Hamburg federal state authority supposedly because of shortened service life due to decay. With regard to wood research, however, it is often suggested that use of timber is suitable for weathered structures as long as constructive protection measures will be observed. In order to unravel the reasons for the shortened service life in Hamburg, several bridges were examined by visual assessment focussing on decay and especially on design. Thus, details of design which affect the durability of individual bridge components and favour damage propagation as well as subsequent decay were primarily detected. In this respect, faulty planning measures and insufficient wood protection is consequently considered as the main cause of the short service life in Hamburg. Giving examples of pedestrian timber bridges, this practical report illustrates several essential faults of protective design which are still being made in planning and construction of naturally weathered timber structures. However, proven solutions are already available and emphasis is placed on constructive solutions with a positive influence on structure durability.
K Robbers, J Fromm, E Melcher
Role of microbiota in wood degradation by Reticulitermes grassei and Bursaphelenchus xylophilus
2022 - IRG/WP 22-20684
Xylophagous organisms can cause damage both in forests and in felled wood. Bursaphelenchus xylophilus, which causes "Sudden Pine Wilting" in coniferous forest masses, and is currently considered a quarantine organism in the European Union. On the other hand, structural and carpentry wood is affected by subterranean termites (Reticulitermes spp.), that cause serious damage, both in buildings and furniture. Solutions for the control of both organisms have been evaluated, and mainly based on chemical or physical treatments. Lately more eco-sustainable biocontrol and/or bioprotection techniques are being investigated. Among these techniques, the modification of the associated microbiota is being studied, in nematode or entomopathogenic microorganisms, with metabolites that are capable of controlling both organisms. As these products are of biological origin they may minimize the environmental impact. The application of these latest techniques requires a deep understanding of the associated microbiota. Therefore, the objective of this work has been to identify the microbiota present in Bursaphelenchus xylophilus and Reticulitermes grassei, as well as their main enzymatic activities and how they may play important roles in the degradation of wood. The results have shown cellulase, chitinase and protease activities, enzymes that could serve as indicative parameters in the control of both organisms. This study opens future treatment techniques against both pests, within a sustainable bioeconomy.
L Robertson, S Rames, M Uriel, J M González, F Llinares, S M Santos, M T Troya