The conservation of a wooden nabataean coffin box from jordan – application of non-destructive ultrasonic technique

In this study, a wooden Nabataean coffin box from Jordan was examined and investigated for its conservation. The previously neglected coffin box was subject to various problems such as fragility, structural disintegration, and biological degradation. Microscopic examination using transmitted light microscope and scanning electron microscope showed the coffin box to be constructed of Lebanon cedar wood. Microbiological investigations allowed the isolation and identification of the fungal and bacterial species that have contributed to the biological degradation of the object. Non-destructive ultrasonic velocity measurements were carried out on the coffin wood to evaluate its deterioration level and to assess the effectiveness of consolidation treatments. Based on these analyses, several conservation processes were carried out on the object. These include cleaning, sterilization, consolidation, and reconstruction. For the consolidation of the coffin box, four different consolidation products were tested. Using ultrasonic technique, Paraloid B72 proved to be the most effective consolidation material for application on the coffin.

Resonance and time-of-flight methods for evaluating the modulus of elasticity of particleboards at different humid conditions

Non-destructive testing of wood panels by either resonance or time-of-flight (TOF) methods provides possibilities for predicting their static bending properties. In the present study, three non-destructive devices (BING – Beam Identification by Non-destructive Grading by CIRAD, Montpellier, France, Fakopp Ultrasonic Timer and Sylvatest TRIO) were used for measuring the dynamic stiffness of different particleboard types. Fakopp Ultrasonic Timer and Sylvatest TRIO produce ultrasonic pulses to measure the sound velocity while BING uses resonance frequencies. Commercially produced particleboards with different thickness and densities were used to measure the dynamic modulus of elasticity (MOEdyn) in two directions (parallel and perpendicular to the production line) and at three different humidity levels (dry – 35%, standard – 65% and wet – 85% RH in constant temperature of 20°C ). MOEdyn of particleboards were correlated with the static moduli of elasticity (MOEstat) and rupture (MORstat). It was found that the non-destructive methods gave higher MOEdyn values in both production directions than that of MOEstat values. MOEdyn was found to decrease from dry to wet conditions. A very strong and statistically significant correlation existed between MOEdyn and static bending properties. MOEdyn correlated stronger to MOEstat than MORstat. At different humidity level, all three methods- Fakopp Ultrasonic Timer, BING and Sylvatest TRIO analyses showed good predicting capabilities to estimate MOEstat and MORstat of different particleboard types with high level of accuracy.