Real-Time Detection of Overloads on the Plasma-Facing Components of Wendelstein 7-X

Wendelstein 7-X (W7-X) is the leading experiment on the path of demonstrating that stellarators are a feasible concept for a future power plant. One of its major goals is to prove quasi-steady-state operation in a reactor-relevant parameter regime. The surveillance and protection of the water-cooled plasma-facing components (PFCs) against overheating is fundamental to guarantee a safe steady-state high-heat-flux operation. The system has to detect thermal events in real-time and timely interrupt operation if it detects a critical event. The fast reaction times required to prevent damage to the device make it imperative to automate fully the image analysis algorithms. During the past operational phases, W7-X was equipped with inertially cooled test divertor units and the system still required manual supervision. With the experience gained, we have designed a new real-time PFC protection system based on image processing techniques. It uses a precise registration of the entire field of view against the CAD model to determine the temperature limits and thermal properties of the different PFCs. Instead of reacting when the temperature limits are breached in certain regions of interest, the system predicts when an overload will occur based on a heat flux estimation, triggering the interlock system in advance to compensate for the system delay. To conclude, we present our research roadmap towards a feedback control system of thermal loads to prevent unnecessary plasma interruptions in long high-performance plasmas

Kriterien der Modellwahl in anwendungsdominierter Forschung

Wilholt T. Kriterien der Modellwahl in anwendungsdominierter Forschung. In: Bluhm R, Nimtz C, eds. Ausgewählte Beiträge zu den Sektionen der GAP.5: Fünfter Internationaler Kongress der Gesellschaft für Analytische Philosophie, Bielefeld, 22. - 26. September 2003. Paderborn: Mentis; 2004: 140-156

Von der Kita zum LK. Frühe Stationen einer Leseebiographie oder warum Langeweile ein Lektüreerlebnis sein kann (und muss)

Voß T. Von der Kita zum LK. Frühe Stationen einer Leseebiographie oder warum Langeweile ein Lektüreerlebnis sein kann (und muss). In: Bluhm L, Ladenthin V, Neuhaus S, eds. Literatur als Lebensform. Eine Sammlung lesebiographischer Essays. Marburg: Tectum; 2016: 243-254

Influence of preoperative skin sealing with cyanoacrylate on microbial contamination of surgical wounds following trauma surgery: a prospective, blinded, controlled observational study

Objective: Intraoperative bacterial contamination is a risk factor for surgical site infections (SSIs). This prospective, randomized, blinded, controlled trial (Reg. No. BB08/12) investigated the effect of a cyanoacrylate-based skin sealant (InteguSeal) on intraoperative wound contamination during trauma surgery. Methods: A total of 128 patients undergoing trauma surgery were assigned randomly to an intervention (n = 62) or a control group (n = 66). Surgical sites were investigated at three locations: maximum incision depth (base), wound margin prior to wound closure (margin), and the surgical sutures (suture). Colony-forming units (CFU) were counted after 48 h of incubation. Results: Overall, significantly lower CFU counts were obtained for samples from the intervention group at all three sample sites compared to the control group. The difference, however, was only significant for the suture site (p = 0.040). Conclusions: Preoperative sealing reduced microbial contamination on sutures during surgery, while the overall wound contamination remained unchanged. Hence, prevention of the clinically more relevant deep SSIs may not be expected. However, this study was not designed to detect differences in the rate of SSI. The role of the reduction in suture contamination with regard to the prevention of SSI remains to be evaluated