DIGITALIZATION AND DATA MANAGEMENT IN AIRCRAFT MAINTENANCE BASED ON THE EXAMPLE OF THE COMPOSITE REPAIR PROCESS

The digital transformation poses a major challenge to the aviation industry with its diverse fields of operations and its mostly historically evolved organizational structure. But there is a lot of potential in the individual organizations for increasing efficiency and reducing obstacles for interoperability by establishing different digitalization concepts. In the past, research has been conducted on various technologies such as assistance systems, automation or inspection and image processing methodologies in the field of composite repair. However, digitalizing individual process steps using a new technology does not necessarily mean that it will also result in a more efficient overall process. For more efficient processes and the implementation of the vision of a digital twin, the digitalization and consideration of the respective holistic process is necessary. Data consistency, which should run like a thread through all process stages is a key factor and requires a corresponding data management concept. The repair process for fiber-reinforced composite structures, see Figure 1, is the basis for the development of a vision for a digital transformation in this work. The reason for this is, that the tasks in this process are usually carried out manually. The resulting media disruptions during the technical execution as well as during the final documentation limit the usability of information. This leads to an additional effort for information interpretation during the process execution and inhibits the potential for a data-based learning and improvement process. In the first part of this paper, the individual process steps are presented according to the current state of the art. This is followed by a process modification doing research regarding suitable technology concepts, which could be used to allow the complete digitalization of the process flow. Based on this, a corresponding data management system for the modified process will is designed, that enables an interaction between the process itself and the digital twin

Imaging incorporation of circulating docosahexaenoic acid into the human brain using positron emission tomography

Docosahexaenoic acid (DHA; 22:6n-3) is a critical constituent of the brain, but its metabolism has not been measured in the human brain in vivo. In monkeys, using positron emission tomography (PET), we first showed that intravenously injected [1-11C]DHA mostly entered nonbrain organs, with ∼0.5% entering the brain. Then, using PET and intravenous [1-11C]DHA in 14 healthy adult humans, we quantitatively imaged regional rates of incorporation (K*) of DHA. We also imaged regional cerebral blood flow (rCBF) using PET and intravenous [15O]water. Values of K* for DHA were higher in gray than white matter regions and correlated significantly with values of rCBF in 12 of 14 subjects despite evidence that rCBF does not directly influence K*. For the entire human brain, the net DHA incorporation rate Jin, the product of K*, and the unesterified plasma DHA concentration equaled 3.8 ± 1.7 mg/day. This net rate is equivalent to the net rate of DHA consumption by brain and, considering the reported amount of DHA in brain, indicates that the half-life of DHA in the human brain approximates 2.5 years. Thus, PET with [1-11C]DHA can be used to quantify regional and global human brain DHA metabolism in relation to health and disease