FlexEl (United States)

Qualification, which is the process of demonstrating that a product is capable of meeting specified requirements, is a costly and lengthy part of the product development process. This paper discusses the challenges that companies face when qualifying their products in an environment of abbreviated product development cycles, changing environmental regulations, which require the use of new materials or processes, and a complex and diffuse supply chain. A more comprehensive approach to product qualification involving the use of physics-of-failure principles, prognostics and health management techniques, and qualification at every stage of product development that builds on earlier work and industry standards is presented here.

For large trees without a continuous sequence of growth rings in their trunk, such as the African baobab (Adansonia digitata L.), the only accurate method for age determination is radiocarbon dating. As of today, this method was limited to dating samples collected from the remains of dead specimens. Our research extends significantly the dating of such trees to large live specimens with inner cavities. The new approach is based on collecting samples from the cavities and their subsequent radiocarbon dating. The giant two-stemmed Platland tree, also known as Sunland baobab, was investigated by using this new approach. AMS radiocarbon dates of the oldest sample segments originating from the two inner cavities indicate that the large stem I (364.5 m3) is 750 ± 75 years old, while the much smaller stem II (136.7 m3) has 1,060 ± 75 years. Results also show that stem I is still growing very fast, while the older stem II slowed down consistently its growth over the past 250 years. The complete mapping of Platland tree determined an overall wood volume of 501.2 m3. Dating results demonstrate that the size–age relation cannot be used for estimating accurately the age of African baobabs.

The article reports the first radiocarbon dating of a live African baobab (Adansonia digitata L.), by investigating wood samples collected from 2 inner cavities of the very large 2-stemmed Platland tree of South Africa. Some 16 segments extracted from determined positions of the samples, which correspond to a depth of up to 15–20 cm in the wood, were processed and analyzed by accelerator mass spectrometry (AMS). Calibrated ages of segments are not correlated with their positions in the stems of the tree. Dating results indicate that the segments originate from new growth layers, with a thickness of several centimeters, which cover the original old wood. Four new growth layers were dated before the reference year AD 1950 and 2 layers were dated post-AD 1950, in the post-bomb period. Formation of these layers was triggered by major damage inside the cavities. Fire episodes are the only possible explanation for such successive major wounds over large areas or over the entire area of the inner cavities of the Platland tree, able to trigger regrowth.