The role of the bilateral subcutaneous plate in the minimal invasive stabilization of fragility fractures of the pelvis

in Trauma Case Reports (2022), 42

Introduction: Anterior pelvic ring fractures are common in geriatric patients. Current treatment algorithms recommend osteosynthesis if no pain free mobilisation is possible. For this a multitude of ... [more ▼]

Introduction: Anterior pelvic ring fractures are common in geriatric patients. Current treatment algorithms recommend osteosynthesis if no pain free mobilisation is possible. For this a multitude of surgical techniques have been described. Among these the Supraacetabular External Fixator (SEF) is regarded a simple and effective surgical procedure. However, this technique is associated with significant drawbacks. Alternatively, there is the option of an internal fixator or a formal plate osteosynthesis. It is the objective of this case report to present the Subcutaneous Iliopubic Plate (SIP) in a fragility fracture of the anterior and posterior pelvic ring. Case report: An 83-year-old female patient sustained a fracture of the anterior pelvic ring, the lateral sacrum and the medial femoral neck. After initially refusing any surgery, the patient agreed to have the endoprosthesis implanted first, and then secondarily to dorsoventral osteosynthesis of the pelvis. Dorsally a transiliosacral screw osteosynthesis was performed. Anteriorly a bilateral subcutaneous iliopubic plate-osteosynthesis was chosen, a plate position that is anterior to the aponeurosis. Conclusions: The subcutaneous plate has proven to be a quick and uncomplicated surgical procedure that is significantly better tolerated by patients than external stabilization. [less ▲]

Experimentelle Bewertung der Spannungen und der zugehörigen Implantate bei anterioren Beckenfrakturen vom Typ I

Scientific Conference (2022, October 28)

A Gaussian damage function combined with sliced finite-element meshing for damage detection

in Journal of Civil Structural Health Monitoring (2022)

Bridges are among the most important components of transportation systems. Timely damage detection of these structures not only ensures reliability but also prevents catastrophic failures. This paper ... [more ▼]

Bridges are among the most important components of transportation systems. Timely damage detection of these structures not only ensures reliability but also prevents catastrophic failures. This paper addresses the damage assessment of bridges based on model updating techniques. Artificial damage was introduced to a beam that was a part of a real prestressed concrete bridge. The magnitude of the damage was increased stepwise, and static loading experiments were conducted in each step. A linear Finite-Element (FE) model with solid elements that were clustered into slices was utilised. A Gaussian bell-shaped curve was used as a damage function to describe the crack location using only three parameters. The experiments focused on sagging under dead load. Damage identification was performed in two steps using a coarse and a refined model. Initially, the FE model with a coarse mesh was updated to approximately localise the damage. Then, the FE model is refined in the vicinity of the approximately localised damage, and damage identification was accurately achieved. The results show that after the second step, the maximum error value of damage localisation is less than 0.5%. This approach could be later used to detect small damages that are not visible. [less ▲]

Integrating technology, education and practice to change energy behaviours in schools

in CLIMA 2022 conference (2022, May)

Schools are learning communities where multiple stakeholders can collaborate to learn about energy efficiency, including via formal curricula, non-formal learning and day-to-day practices. Furthermore, by ... [more ▼]

Schools are learning communities where multiple stakeholders can collaborate to learn about energy efficiency, including via formal curricula, non-formal learning and day-to-day practices. Furthermore, by improving energy literacy among building occupants, the energy efficiency of schools can be improved. However, turning schools into learning communities rather than learning organizations is still problematic. This article details a case study realised in the form of the ENERGE project, which integrates technological, educational and practical activities in 13 post-primary schools from 6 European countries. Owing to an extensive collaboration of diverse stakeholders, the ENERGE project resulted in the origination of a learning community around energy efficiency in the schools. The outcomes of building a learning community within the ENERGE project included: capacity building (in the form of the ENERGE Committees and Teacher Network), the introduction of digital education (via the ENERGE digital platform), development of curriculum-based modules to raise energy literacy, and the establishment of a viable model for expanding ENERGE experience to other schools. The article concludes by explaining the benefits of the ENERGE approach for stakeholders. [less ▲]

Umstellung eines Campingplatzes auf solare Energieversorgung

in Konferenzbeiträge Bauphysiktage Kaiserslautern 2022 (2022), 5

Der fortschreitende Klimawandel verlangt ein Umschwenken, weg von der fossilen Energieversorgung und hin zu den Erneuerbaren, wobei nachhaltige Tourismusangebote auch verstärkt einbezogen werden müssen ... [more ▼]

Der fortschreitende Klimawandel verlangt ein Umschwenken, weg von der fossilen Energieversorgung und hin zu den Erneuerbaren, wobei nachhaltige Tourismusangebote auch verstärkt einbezogen werden müssen. Der Campingplatz Treviris liegt auf dem Gelände des Rudervereins Treviris Trier und verzeichnet jährlich von Mitte April bis Mitte Oktober zwischen 40 und 50.000 Übernachtungen. Im Zuge des Neubaus des Bootshauses wird der vorhandene Gasanschluss zurückgebaut und die gesamte Wärme- und Stromversorgung der Liegenschaft muss auf regenerative Energien umgestellt werden. So soll der Bedarf des Campingplatzes, des Bootshauses (KfW 40 EE), der angegliederten Wohnbebauung mit zehn Wohneinheiten (KfW 40+) sowie mehrere Ladestationen emissionsneutral durch Sonnenenergie versorgt werden. Hauptbestandteile des Konzeptes sind eine 105 kWpeak PV Anlage mit 90 kWh Batteriespeicher sowie zwei Wärmepumpen, die um eine 80 m² hybride solarthermische Photovoltaikanlage (PVT) auf dem Campingplatz ergänzt werden soll. Insbesondere die Warmwasserversorgung des Campingplatzes ist hierbei eine Herausforderung, da die auftretenden Leistungsspitzen von 4m3 Warmwasser (WW) in 2 h nicht ausschließlich mittels Wärmepumpe bereitgestellt werden können. Es wird auf Wärmespeicher mit zentraler Frischwasserstation zurückgegriffen. Für die Dimensionierung der Hauptkomponenten: PVT Feld, Wärmepumpe und Pufferspeicher wird eine Zeitreihenanalyse mit variierendem Bedarf und schwankendem Solarangebot durchgeführt. [less ▲]

Bridge damage assessment based on static and dynamic flexibility matrices

in Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability (2022)

Being an indispensable part of transportation systems, Structural Health Monitoring (SHM) of bridges has been increasingly studied. Various SHM techniques not only enhance reliability and safety but also ... [more ▼]

Being an indispensable part of transportation systems, Structural Health Monitoring (SHM) of bridges has been increasingly studied. Various SHM techniques not only enhance reliability and safety but also reduce maintenance costs. Various bridge deteriorations change the structural properties, such as flexibility and stiffness. Therefore, damage assessment can be achieved by monitoring the structural matrices of bridges and tracking the deviations from the healthy-state or reference data. This paper focuses on damage detection of a prestressed concrete beam from a demolished bridge based on the flexibility matrix. The dynamic and static flexibility matrices are calculated numerically and experimentally when the beam is undamaged. The simulated and measured static flexibility matrices differ by only about 5 %. Additionally, the numerical dynamic flexibility matrix is strongly correlated with static results. The findings of this study can be employed as a basis for future damage detection applications when artificial damage is introduced. [less ▲]

Dichtungsanalyse von Elastomer-O-Ringen unter Hochdruck bei Raum- und Tieftemperatur

in Repplinger, Christian (Ed.) 47. VDI-Jahrestagung: Schadensanalyse 2021 - Wasserstoff in metallischen Bauteilen und Mediale und klimatische Beanspruchung von polymeren Produkten (2021, October)

Verringerung des Temperatureinflusses bei der Überwachung von Brücken am Beispiel von Messdaten aus Luxemburg

Conference given outside the academic context (2021)

A rising number of concrete bridges are showing increasing damage due to corrosion and fatigue. In addition to the regular standard visual inspection, the bridge’s condition can also be recorded using ... [more ▼]

A rising number of concrete bridges are showing increasing damage due to corrosion and fatigue. In addition to the regular standard visual inspection, the bridge’s condition can also be recorded using additional tests with repeated static loading and/or dynamic tests. To determine any damage to a structure and to check its structural stability, it is crucial to know the exact system properties of the bridge in its undamaged reference state. The system behavior is influenced by damage and bearing conditions and environmental influences, such as the structure’s temperature. The influence of temperature can even cause larger changes in the measured quantities (bending line or modal parameters) than real damage. Therefore, temperature effects should be compensated before any condition analysis. The present work aims to demonstrate the influence of different bearing types and temperature on a real bridge beam. For this purpose, various static and dynamic tests were performed in the undamaged reference state. [less ▲]

Repeatability and precision of different static deflection measurements on a real bridge-part under outdoor conditions in view of damage detection

in Cunha, A.; Caetano, E. (Eds.) Proceedings of the 10th International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII 10 (2021, July)

A large number of concrete bridges show increasing damage due to corrosion and fatigue. The traditional visual inspection and subsequent assessment of concrete bridges is carried out regularly by an ... [more ▼]

A large number of concrete bridges show increasing damage due to corrosion and fatigue. The traditional visual inspection and subsequent assessment of concrete bridges is carried out regularly by an experienced engineer. This type of inspection can be time-consuming, costly and leading to errors. Hence, there is a great interest in complementary, alternative and easy-to-implement methods for condition monitoring of bridges. The University of Luxembourg tested different approaches on a part of a real bridge. Various tests were performed in the healthy reference state, e.g. loading tests with a movable test load according to today’s standards. The measurements in the reference state were repeated several times under outdoor conditions to monitor and document the real temperature influence. Displacement transducers were set up in the vertical and horizontal directions. Simultaneously, a new approach was used for determining the deflection with a laser-based system, that measured the displacements in the bridge’s longitudinal direction by an oblique reflector panel under a well-defined angle. The data gained from the laser-based measurement system were compared to the data from classical displacement transducers. In general, the comparison of the two measuring systems shows quite similar results. [less ▲]

Field monitoring data on a residential exhaust air heat pump system (air-to-air heat pump)

in Data in Brief (2021)

This data article presents the raw data used in the article “Experimental and analytical evaluation of exhaust air heat pumps in ventilation-based heating systems” (in review). The data set contains ... [more ▼]

This data article presents the raw data used in the article “Experimental and analytical evaluation of exhaust air heat pumps in ventilation-based heating systems” (in review). The data set contains measurement results of a field monitoring on a residential exhaust air heat pump system (air-to-air heat pump) in Germany. This data could be used to investigate the dynamic behaviour and performance of the exhaust air heat pump systems. The data set contains air temperature and humidity of all four sides of the heat pump unit. Moreover, the electrical consumption of the unit and the dynamic pressure difference on the exhaust side (as indication of the air volume rate) could be also found in the data set. [less ▲]