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A hypersonic shock tunnel is a primary tool used for basic experimental research and may be used in engineering and university courses to study compressible flows involving shock waves. In the present study, a pneumatically operated shock tunnel is demonstrated for hypersonic flow studies. The high-pressure nitrogen gas is used to drive a pneumatic cylinder, which is used to burst the thin metal diaphragms. Tunnel-free stream conditions are quantified using the measured pressure values and by applying shock tube relations. The free-stream Mach number of 5.5–7.2 is achieved by varying the bursting pressure and test gas pressure from 2.1 to 4.5 bars and 0.2 to 0.5 bar, respectively. The simulation is performed and the shock standoff distance quantified, and the stagnation pressures measured. The results demonstrate that the pneumatically operated tunnel enhanced operation capacity compared to the manually operated tunnel and well suits the academic hypersonic research and developmental activities.

Aim This work aims to determine the glycerophospholipid (GPL) abundance between Oesophageal adenocarcinoma (OA) and proximal non-cancerous tissue at multiple levels using Desorption Electrospray Ionisation Mass spectrometry (DESI-MS) tissue imaging. Background & Methods The prevalence of Oesophageal cancer in the United Kingdom has steadily risen since the 1970s. The prognosis for most patients is poor, with two thirds presenting with incurable disease. The abundance of lipids in OA has been shown to be atypical of normal cellular metabolism.1 This work utilises mass spectrometry imaging to identify variations in lipid abundance between OA and normal oesophagus (NO). Tissue was sampled from specimens dissected immediately post-resection from the tumour and at 5-centimetre intervals in the proximal oesophagus. DESI-MS tissue imaging, an ambient form of Mass Spectrometry, was performed to identify GPLs.2 DESI-MS images were correlated with Hematoxylin and Eosin staining (current gold standard). Principle component analysis with a supervised model classified tissue types by sensitivity and specificity. Results Tissue analysis confirmed unsaturated Phosphatidylglycerols and Phosphatidic acids were most abundant in OA compared to NO (p The abundance of several unsaturated GPL classes decreased proportionally in tissue sections at 5 and 10 centimetres from the primary tumour. Gene set enrichment has demonstrated potential dysregulation of this pathway in the literature. Conclusions This work highlights an important variant of lipid metabolism in OA, identified by DESI-MS. There is a significant overabundance of unsaturated Phosphatidylglycerol’s in OA compared to proximal NO. In addition, the unsaturated GPL classes found in the cancer become increasingly saturated at 5cm and 10cm from the tumour site. This variation in lipid molecular structure suggests a novel pathway for potential therapeutic modulation.