Purpose: Flexible intramedullary nails (FIN) are increasingly used in the management of paediatric tibial and femoral fractures. Concerns have recently been raised regarding the use of FIN in older children. The aim of this study was to determine how effective FIN is in treating tibial and femoral fractures in adolescents. Methods: Patients aged 11 years or older undergoing FIN for tibial and femoral fractures between 2003 and 2009 were identified. Radiographs and case notes were reviewed to identify complications. Results: Thirty-five consecutive adolescent patients underwent FIN for tibial ( n = 21) and femoral fractures ( n = 15), with a mean age of 12.9 years. The mean radiographic follow up was 29 weeks. Sixty percent (60%, n = 9) and 38% ( n = 9) of femoral and tibial fractures, respectively, malunited. Fracture severity was associated with increased malunion for both tibial and femoral fractures ( P = 0.046 and P = 0.044, respectively). Two femoral fractures took longer than 20 weeks to unite and seven tibial fractures took longer than 16 weeks to unite. Conclusion: The higher than expected rates of malunion and delayed union in this study suggest that other treatments should be considered when treating adolescents with unstable tibial or femoral fractures.

Train-borne localization systems as a key component of future signalling systems are expected to offer huge economic and operational advances for the railway transportation sector. However, the reliable provision of a track-selective and constantly available location information is still unsolved and prevents the introduction of such systems so far. A contribution to overcome this issue is presented here. We show a recursive multistage filtering approach with an increased cross-track positioning accuracy, which is decisive to ensure track-selectivity. This is achieved by exploiting track-geometry constraints known in advance, as there are strict rules for the construction of railway tracks. Additionally, compact geometric track-maps can be extracted during the filtering process which are beneficial for existing train localization approaches. The filter was derived applying approximate Bayesian inference. The geometry constraints are directly incorporated in the filter design, utilizing an interacting multiple model (IMM) filter and extended Kalman filters (EKF). Throughout simulations the performance of the filter is analyzed and discussed thereafter.

In this paper, we present a method to generate compact geometric track-maps for train-borne localization applications. Therefore, we first give a brief overview on the purpose of track maps in train-positioning applications. It becomes apparent that there are hardly any adequate methods to generate suitable geometric track-maps. This is why we present a novel map generation procedure. It uses an optimization formulation to find the continuous sequence of track geometries that fits the available measurement data best. The optimization is initialized with the results from a localization filter [1] developed in our previous work. The localization filter also provides the required information for shape identification and measurement association. The presented approach will be evaluated on simulated data as well as on real measurements.

State-of-health (SoH) estimation is one of the key tasks of a battery management system, (BMS) as battery aging results in capacity- and power fade that must be accounted for by the BMS to ensure safe operation over the battery’s lifetime. In this study, an online SoH estimator approach for NMC Li-ion batteries is presented which is suitable for implementation in a BMS. It is based on an observer structure in which the difference between a calculated and expected open-circuit voltage (OCV) is used for online SoH estimation. The estimator is parameterized and evaluated using real measurement data. The data were recorded for more than two years on an electrified bus fleet of 10 buses operated in a mild European climate and used regularly in the urban transport sector. Each bus is equipped with four NMC Li-ion batteries. Every battery has an energy of 30.6 kWh. Additionally, two full-capacity checkup measurements were performed for one of the operated batteries: one directly after production and one after two years of operation. Initial validation results demonstrated a SoH estimation accuracy of ±0.5% compared to the last checkup measurement.

Investigating the temperature behavior of lithium-ion battery cells has become an important part of today’s research and development. The main reason for this is that the temperature profile of a battery cell changes during aging. By using Differential Thermal Voltammetry (DTV), new possibilities are opened up, especially since this diagnostic method is designed to work in operando by only requiring voltage and temperature readings. In this study, a batch of NMC-21700 cells were aged in calendar and cyclic manners. After a specified aging cycle was complete, a check-up measurement was performed. During this time, the cycler collected the electrical measuring values, while a negative temperature coefficient thermistor, which was located on the cell, was used to record the temperature fluctuations. The data were then evaluated by using the DTV analysis technique. By comparing the characteristic points of DTV, correlations between the changing curve characteristics and the capacity loss, and therefore the aging of the respective cell, were established. Based on these results, a simple model suitable for online State of Health (SoH) is derived and validated, showing an estimation accuracy of $1.1$%.

Purpose: Bipolar radio-frequency-induced thermofusion (BiRTh) of intestinal tissue might replace conventional stapling devices which are associated with technical and functional complications. Previous results of our study group confirmed the feasibility to fuse intestinal tissue using BiRTh-induced thermofusion ex vivo. The aim of this study was now to evaluate the efficacy of fusing intestinal tissue in vivo by BiRTh-induced thermofusion. Materials and methods: In male Wistar rats a blind bowel originating from the caecum was closed either by BiRTh (n = 24) or conventional suture (n = 16). At 6 h, 48 h, 4 days, and 2 weeks after the procedure caecum bursting pressure was measured to compare both groups. Results: In total 18 of 21 (85.7%) thermofused and 15 of 16 (93.7%) sutured cecal stumps were primarily tight and leakage-proof (p > 0.05). The operative time was comparable in both groups without significant differences. Both groups showed increases in bursting pressure over the post-operative period. The mean bursting pressure for thermofusion was 47.8, 48.3, 55.2, and 68.0 mmHg, compared to 69.8, 51.5, 70.0 and 71.0 mmHg in the hand-sutured group (p > 0.05) after 6 h, 48 h, 4 days, and 2 weeks, respectively. Conclusion: These results suggest that BiRTh-induced thermofusion is a safe and feasible method for fusing intestinal tissue in this experimental in vivo model and could be an innovative approach for achieving gastrointestinal anastomoses.