Characterization of Archaeological Wood Stained with Bat Excretions Using Various Analytical Techniques (original) (raw)
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This paper focuses on investigating deterioration of archaeological wood which were used as architectural elements such as ceilings, doors, floors, domes, mashrabias. Nine samples were collected from different architectural elements, then a scanning electron microscope (SEM) study was undertaken, to monitor the significant structural changes in the wood samples according to their function. SEM data, however, show that loads and stresses affect the anatomical structure of wood badly, in addition to other deterioration factors, especially in the large wooden objects and structural wooden elements. The main problem is the separation and fractures resulting in the wood structure which might cause the structure to collapse. So, developing new materials and techniques that could be used in the treatment and conservation of archaeological wood subjected to this type of deterioration is restricted at understanding condition of this wood.
ASSESSMENT OF COMMONLY USED CLEANING METHODS ON THE ANATOMICAL STRUCTURE OF ARCHAEOLOGICAL WOOD
International Journal of Conservation Science, 2013
This study was conducted to diagnose and evaluate the effect of commonly used cleaning methods in Egypt on the anatomical structure of archaeological wood samples. Beech wood samples, which were taken from anonymous mashrabia, have been cleaned mechanically and chemically, then a scanning electron microscope (SEM) study was undertaken, to monitor any significant structural changes in wood samples due to cleaning processes. SEM data, however, show that cleaning procedures, both mechanical and chemical, affect the anatomical structure of wood, and do not achieve the best result. The main problem is that the effect of reagents cannot be easily removed from the wood structure. Ethyl alcohol proved to have the minimal effect on the wood structure in this study.
2016
The aim of this paper is to examine and analyze a wooden face that was covered with a transparent layer of wax after finishing the mask. The use of wax and encaustic painting was used in Ancient Egypt during the Greco-Roman period, but it was an extremely rare technique in the Egyptian dynasties. The wooden face that was chosen for this study was carefully examined using light microscopy to identify the wood, which proved to be native sycomore fig (Ficus sycomorus). Digital microscope and Scanning Electron Microscope (SEM) were used to assess decay of the outer exposed surface that had been covered in the past with a preparation layer composed of calcium carbonate. SEM micrographs showed clear decay of the cell walls due to the penetration of both the preparation layer and fungal hyphae. Microbiological investigation indicated the presence a bacterial and fungal infestation. The wood was infected infected by Aspergillus niger and Ulocladium sp fungi and Pediococcus dextrinicus bacteria. Further assessment was done by X-Ray Diffraction (XRD) to calculate the decrease of cellulose crystallinity according to Segal and Fourier Transform spectroscopy (FTIR) to detect the changes of the main wood components (cellulose, hemicellulose, lignin).
Archaeometry, 2009
A series of 112 waterlogged archaeological wood samples of different provenances, wood species, burial times and states of preservation were analysed with the aim of assessing the validity (in terms of limits and reliability) of procedures conventionally used in the pulp and paper industry, to evaluate the state of preservation of decayed wood. In particular, the extent of any damage wrought on decayed wood tissue by the repetitive cycles that characterize these procedures was evaluated as a function of the degradation of the samples. The results indicated that standard methodologies give reliable measurements regardless of the extent of wood decay. However, it is essential to compare these data with those of non-decayed wood that has been measured using the same procedures to take account of the errors that are inherent in these methodologies and that affect measurements.
Polymer Degradation and Stability, 2017
An in-depth investigation of the wood chemical changes induced by degrading agents in dry burial environments was undertaken by evaluating the degradation state of eleven wood samples from dry archaeological sites in Egypt was evaluated by combining the information obtained by scanning electron microscopy (SEM), wet chemical analysis (WCA), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and analytical pyrolysis gas chromatography mass spectrometry with in situ silylation (Py(HMDS)-GC-MS). The samples belonged to five different wood species (Faidherbia albida, Ficus sycomorus, Taxus baccata, Pinus sylvestris and Tamarix sp.) and came from three different archaeological sites corresponding to three different time periods (from ca. 1700 BC to ca. 1700 AD). The results were compared with sound reference wood of the same species. SEM enabled a fungal attack to be identified in some of the samples. Wet chemical analysis highlighted the preferential loss of lignin or carbohydrates in these samples, but also showed unusually high values of water-soluble substances in most of them. FTIR spectra acquired before and after the extraction of the samples revealed that this soluble fraction generally contained depolymerised carbohydrates and/or lignin units. Py(HMDS)-GC-MS was applied without any sample pre-treatment and was used to assess the alteration/depolymerisation of the individual wood components, thus complementing the picture regarding the chemical changes.
RESTORATION AND PRESERVATION OF THE WOODEN CEILING OF AL-ASHRAF QAYTBAY MADRESSA, CAIRO EGYPT
The painted ceilings of Qaitbay's madrassa is one of the Egypt's great monuments and among the oldest in the Islamic civilization, dating back to the Garkssy Mamluk period (879 AH/1474 AD). It represents an exceptional example of the quality and extent of medieval woodworking in Egypt. The wooden ceiling of Qaitbay's madrassa had been affected by an extensive deterioration due to many factors, such as loss of colors, cracking, soot deposition, and losses of materials/units, insects' holes, and fungi growth, in addition to formation of corrosion products of its metallic parts. The main aim of the present paper is the characterization and investigation of the different components employed in the decorated ceiling of Madrassa of Qaytbay as wood units, painting ground, pigments, gilding, binding media and products of deterioration. Scanning Electron Microscope coupled with EDX analysis, Optical Light Microscope, X-ray diffraction and Infrared analysis were applied for investigation. Biological study was done. We present the results of identifying the wood species and insects of the ceiling of the Qaitbay's madrassa, which the aim of the providing information not only of the benefit to restoration but also to the historical- artistic background of the artifacts. Also this paper includes the present of its state of conservation for preservation the study will include the documentation, investigation, and analysis before the intervention process. The treatment steps were documented before, during and after the restoration. Preservation of the wood ceiling was carried out including the following: cleaning (mechanical and chemical cleaning), treatment of fungi infection, consolidation and restoration.
PlosOne, 2019
Abydos is a large, complex archaeological site located approximately 500 km south of Cairo in Upper Egypt. The site has served as a cemetery for thousands of years and is where most of the Early Dynastic royal tombs are located. North Abydos includes the Middle Cemetery and the North Cemetery, which are separated from each other by a wadi. The Middle Cemetery was the burial ground for important Sixth Dynasty (2407-2260 BC) officials and over time for thousands of elite and non-elite individuals as well. Excavations at the core area of the Old Kingdom mortuary landscape have revealed many culturally important wooden objects but these are often found with extensive deterioration that can compromise their preservation. The objectives of this study were to characterize the biodegradation that has taken place in excavated wooden objects, elucidate the type of wood degradation present , obtain information on soil properties at the site and identify fungi currently associated with the wood and soils. Light and scanning electron microscopy studies were used to observe the micromorphological characteristics of the wood, and culturing on different media was done to isolate fungi. Identification of the fungi was done by examining morphological characteristics and extracting rDNA from pure cultures and sequencing the ITS region. Wooden objects, made from Cedrus, Juniperus and Acacia as well as several unidentified hardwoods, were found with extensive degradation and were exceedingly fragile. Termite damage was evident and frass from the subterranean termites along with sand particles were present in most woods. Evidence of soft rot attack was found in sections of wood that remained. Fungi isolated from wood and soils were identified as species of Asper-gillus, Chaetomium, Cladosporium, Fusarium, Penicillium, Stemphylium Talaromyces and Trichoderma. Results provide important information on the current condition of the wood and gives insights to the identity of the fungi in wood and soils at the site. These results provide needed information to help develop conservation plans to preserve these degraded and fragile wooden objects. PLOS ONE | https://doi.org/10.1371/journal.pone.
A preliminary study on using enzymes in cleaning archaeological wood
Journal of Archaeological Science, 2012
The main goal of this study was to study and evaluate the effect of hydrolyzing enzymes on the anatomical structure and chemical composition of archaeological wood samples. Pine and beech wood samples, which were taken from anonymous mashrabia, have been cleaned with three types of enzymes then a scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) study were undertaken, to see if any significant structural or chemical differences could be detected between "untreated" and "treated" wood. No dramatic changes in functional groups on the wood surface, as monitored by infrared spectroscopy, occurred in the samples before and after enzymatic cleaning. SEM data, however, show that protease and lipase enzymes may give good results in cleaning wood surface, but the enzyme residues remaining on the cell walls of archaeological wood are another point to consider.