Spring Based Connection of External Wires to a Thin Film Temperature Sensor Integrated Inside a Solid Oxide Fuel Cell.

Thermal management of SOFCs (solid oxide fuel cell) is important for helping to minimise high temperature-related performance losses and maximising cell/stack lifetime. Thin film sensor technology is proposed as an excellent candidate to measure the cell temperature during operation due to its negligible mass, minimal disturbance to normal operation and higher temporal and spatial resolutions. However, the effective application of such sensors in SOFC systems is a challenging endeavour and predicated on incorporating the external wire attachments to complete the electrical circuit. This is because of the high sensitivity of SOFC materials to any interference to operation, limited available space and harsh operating conditions. In this paper, a new concept of packaging external wire attachments to the thin film sensor is described to enable the integration of the sensor in the SOFC system. Temperature measurements have been monitored under OCV and operating condition with the thin film sensor directly from SOFC cathode surface via proposed spring-based wire connection, from room temperature to SOFC operating temperature. The impact of the parameters including contact resistance (Rc) between sensor pads and attached wire on monitored temperature has also been analysed with the contribution of conductive paste. High temporal and spatial resolutions have been obtained with the implemented sensor.

Programmatic change leads to enhanced resource utilization and efficiency in port placement.

BACKGROUND: Central venous port (CVP) placement is performed by a variety of surgeons in different subspecialties, and our previous work suggests that individual surgeons-regardless of training-are the strongest predictor of outcomes. We sought to prospectively evaluate a programmatic shift toward a resource-conscious, patient-focused algorithm for this common and simple surgical procedure. MATERIALS AND METHODS: After implementation of a systems-level program for efficient CVP placement, 78 CVPs were placed by a single surgeon. Primary outcomes were procedure time, total operating room (OR) time, total facility time, and procedure-related complications. These prospective data were compared with retrospective cohorts of surgically placed and interventional radiology-placed CVP. Demographic data were analyzed by chi-square analysis, whereas time data were analyzed by the Wilcoxon rank-sum test. RESULTS: The programmatic delivery (prospective) set showed significantly shorter procedural (median 16 min versus 26-40, P <0.05), OR times (median 36 min versus 46-70, P <0.05), and facility times (median 235 min versus 299-319, P <0.05) except for the interventional radiology facility time (median 187 versus 235, P <0.05). The range of OR time savings with the prospective versus comparison groups was 10-34 min, representing 22%-49% reductions in OR time (P <0.05). Complication rates were not significantly different (P = 0.13). CONCLUSIONS: Through a programmatic change emphasizing efficiency and patient-centered outcomes, procedural/OR/facility time can be reduced greatly without changing complication rates. These data provide compelling evidence that common and ostensibly simple operative procedures can be substantially improved upon with thoughtful, data-driven systems-level enhancements.

Surgeon, not technique, defines outcomes after central venous port insertion.

BACKGROUND: Although central venous access for port placement is common and relatively safe, complications and poor resource utilization occur. We hypothesized that despite the simplicity of port placement, surgeon and/or resident performance-rather than technique-is associated with clinical outcomes and operating room efficiency. MATERIALS AND METHODS: Medical records of 1200 patients who underwent port placement between 2012 and 2015 at our institution were retrospectively reviewed. Insertion route (subclavian, internal jugular, cephalic cutdown), individual surgeon (A-G), surgeon volume, body mass index, patient age, and resident presence were evaluated to determine their association with operating room time, complications, and need for alternate insertion route. RESULTS: On univariate analysis, operating room times were significantly different among individual surgeons, with surgeons E and F having the longest operating room times (50 and 63 versus 31-40 min; P < 0.01) and switching to an alternate method more frequently (13.5% and 21.3%, versus 0%-10.3%, P < 0.01). On multivariate analyses, operating time was increased with elevated body mass index, resident presence, and switching to an alternate method. Individual surgeons had varied effects on operating time with two surgeons found to be the predominant drivers (OR 19 and 27; P < 0.01). With residents excluded, these two surgeons continued to increase operating times (OR 15 and 29; P < 0.01) and procedural complications (OR 3.2 and 5.9; P < 0.05). CONCLUSIONS: Although port placement is ostensibly simple, individual surgeon performance is the primary driver of patient outcome and operative efficiency. In an era requiring optimized resource utilization and outcomes, these data demonstrate potential for enhanced programmatic organization and case distribution.

Performance and Durability of Thin Film Thermocouple Array on a Porous Electrode.

Management of solid oxide fuel cell (SOFC) thermal gradients is vital to limit thermal expansion mismatch and thermal stress. However, owing to harsh operation conditions of SOFCs and limited available space in stack configuration, the number of techniques available to obtain temperature distribution from the cell surface is limited. The authors previously developed and studied a thermocouple array pattern to detect surface temperature distribution on an SOFC in open circuit conditions. In this study, the performance in terms of mechanical durability and oxidation state of the thin film thermoelements of the thermocouple array on the porous SOFC cathode is investigated. A thin-film multi-junction thermocouple array was sputter deposited using a magnetron sputter coater. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) characterisation techniques were carried out to understand characteristics of the thin film before and after temperature (20 °C-800 °C) measurement. Temperature readings from the sensor agreed well with the closely placed commercial thermocouple during heating segments. However, a sensor failure occurred at around 350 °C during the cooling segment. The SEM and XPS tests revealed cracks on the thin film thermoelements and oxidation to the film thickness direction.