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This paper presents a novel experimental method for the study of flow induced noise from underwater vehicles. Here, buoyancy driven models are combined with a hydrophone array in a large water tank. The advantage of the methodology is that the noise comes exclusively from the model. The data were processed using conventional beamforming in two configurations, by either using the whole signal or dividing it into several individual time segments, the so-called short-time beamforming method. The beamforming maps are accurate given the small number of sensors. The second method enabled to track the model location during its travel. The results for each test were consistent especially at high frequencies (from 2 kHz).

Objectives Changes in clot microstructure are increasingly implicated in the pathology of atherosclerosis although most data are from techniques in the remote laboratory using altered blood. We validate the novel biomarker Gel Point in STEMI patients and assess therapeutic interventions. Gel Point marks the transition of blood from a visco-elastic liquid to visco-elastic solid and is rapidly measured using unadulterated blood. The Gel Point provides measurements of three parameters to reflect clot microstructure (fractal dimension ( d f )), real-time clot formation time ( T GP ) and blood clot strength (elasticity at the Gel Point ( G ′ GP )). Methods We prospectively recruited 38 consecutive patients with STEMI undergoing primary percutaneous coronary intervention (pPCI). Venous blood samples were collected on admission, after pPCI and 24 h after admission for assessment of the new biomarkers, standard coagulation tests and scanning electron microscopy (SEM). Results d f after pPCI was lower than d f on admission (mean 1.631 [SD 0.063] vs 1.751 [0.052], p d f at 24 h was similar to that on admission. G ′ GP also showed similar trend to d f (p T GP was prolonged at after-PCI measurement compared with admission (median 854 s [IQR 581–1801] vs 217 [179–305], p d f and G ′ GP were consistent with changes in the SEM images of the mature clot. Conclusions We characterise Gel Point derived markers of clot microstructure in patients admitted with emergency arterial thrombosis. This point of care test can potentially be used to assess the efficacy of therapeutic interventions by measuring changes in clot microstructure.

The development of pulse charging equipment for the unique application to submarine lead acid batteries is described. A prototype pulse charger has been developed and applied to individual twin cell submarine batteries, plus a 20 twin cell pulse charger has been commissioned at the battery manufacturing facility. The paper provides a description of the pulse charging equipment and preliminary test results and analyses using the prototype twin-cell pulse charger, based on application of a range of positive and negative pulse parameters. The tests so far indicate potential benefits may arise from this form of charging, including enhancement of battery charge levels, reduced gas charging (stage 3) times and reduced gas evolution rates.