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Portable gait-asymmetry detection using lowcost hardware and machine learning
No full textGait analysis provides insights into human motion by examining how individuals walk. However, the high cost associated with gait centers prevents conducting gait analysis regularly, reducing opportunities for early detection and prevention of gait-related issues before pain or injuries occur. The approach presented in this paper integrates low-cost yet computationally powerful hardware with signal processing and machine learning to develop a wearable sensor node placed at the pelvis that continuously collects gait data, providing personalized gait analysis. By positioning the wearable at the pelvis, gait asymmetries can be captured accurately. The approach is validated in a laboratory experiment with 15 participants walking on a treadmill and verified in a free-moving environment. Results indicate that the wearable detects gait asymmetries effectively, enhancing applicability in both clinical and non-clinical settings, supporting rehabilitation and preventive care in a cost-efficient manner
Local mechanical stresses can explain the mechanoregulation of bone healing after mandibular reconstruction: an in silico study
No full textObjectives: Recent advancements in mandibular reconstruction, including virtual surgical planning and patient-specific 3D-printed reconstruction plates, have improved surgical precision but have not yet fully optimized the mechanical environment for bone healing. This study aimed to investigate the level of mechanical signals that may promote bone regeneration in mandibular reconstruction with patient-specific plates. Materials and methods: A coupled finite‑element and agent‑based mechanobiological model for mandibular bone healing was developed to predict bone formation after mandibular reconstruction. A finite element model (FEM) of a monosegmental mandibular reconstruction with a patient-specific 3D-printed plate during unilateral clenching was coupled with a 3D agent-based model to simulate cellular activities at the osteotomy sites. Using an established mechano-regulation theory, tissue formation and resorption were simulated based on mechanical signals. The latter were systematically varied to identify thresholds matching clinical observations. Results: Increasing the ossification threshold from 0.15 MPa to 0.30 MPa improved agreement with clinical data, leading to 39% and 69% of bone formation in the anterior and posterior gaps, respectively, after 90 days. Conclusions: The model was able to predict levels of newly-formed bone as per clinical observations. Adaptation of the mechano-regulation theory to the mandibular environment suggested that mandibular bone regeneration might occur at a higher level of mechanical stress than in long bones. Clinical relevance: This study presented a computational framework that could, in the future, be incorporated into the clinical workflow during virtual surgical planning to support the mechanical optimization of patient-specific fixation devices and ultimately enhance the healing outcome
A global perspective on endorheic lake shrinkage: Impacts of anthropogenic and atmospheric factors
No full textEndorheic lakes, critical components of terrestrial hydrology in closed drainage basins, serve as sensitive indicators of environmental and anthropogenic changes (Hassani et al., 2020). This study analyzed 635 endorheic lakes globally using high-resolution satellite datasets to quantify changes in surface area from 2000 to 2021 and identify the underlying causes. Of these, 134 lakes showed noticeable surface area reductions, with the highest rates observed in water-stressed regions, particularly in Asia and Semi-Arid climates. We found that anthropogenic activities, including agricultural expansion, were key drivers of shrinkage in 89 lakes, whereas meteorological factors, such as increased aridity, primarily influenced 45 lakes. For example, irrigation significantly impacted water balance in places like Wadi Al Rayan in Egypt and Chenghai Lake in China, while industrial activities like lithium mining were particularly notable in the basin of the Dongtai Jiner Lake in China. Additionally, changes in climatic variables, including reduced precipitation and heightened evapotranspiration, further exacerbated lake surface reductions in many regions. These findings highlight the complex interplay between human and natural factors affecting lake dynamics often resulting in what is referred to as anthropogenic drought. They offer valuable insights for the sustainable management of endorheic lake ecosystems, emphasizing the need for strategies that address both direct anthropogenic pressures and changes in climatic and environmental factors
Merging nano and macro structure design: opportunities for the structural integrity of steel infrastructure
No full textMerging the macro-level design with the nano-level design in structural engineering, hence, using the superior properties of nanostructured metallic multilayers for protecting fatigue-critical joints of the macrostructure and ensuring the structural integrity of the steel infrastructure are the objectves of a research effort at TU Hamburg. Nanostructured metallic multilayers (NMM) have significantly higher strength, fatigue resistance and ductility than monolithic homogeneous metal cross sections. The superior structural properties of these nanostructured cross sections are known, and so it is surprising why no attempt has been made to date to use nanostructured cross sections in macro cross sections in structural engineering to improve the cross section properties. This paper links the advantages of nanostructured multilayers with the needs of homogeneous metallic macro-cross sections and examines the question to which extent the high-performance material nanolaminate can compensate for the structural weak parts of metallic infrastructure. The welded joint subjected to fatigue is addressed as vulnerable part of metallic infrastructure. The article provides insights on how nanostructured multilayer can potentially contribute to the future of steel construction, further, how nanostructured multilayer can potentially affect fatigue design. The design as well as the maintenance of cyclically loaded metallic infrastructures, such as bridges and offshore wind turbines, are discussed herein and it is shown how sustainability, resource conservation, reduction of CO2 footprint, readiness, security of supply and economic viability of steel infrastructure can potentially be achieved
Die "Designanalyse" als gestaltungsorientiertes Unterrichtsverfahren
No full textIn diesem Beitrag wird die Designanalyse als gestaltungsorientiertes Ausbildungs- und Unterrichtsverfahren der beruflichen Bildung vorgestellt. Sie wird als systematisches Vorgehen zur Erfassung, Bewertung und Weiterentwicklung von Entwurfs- und Produktmerkmalen verstanden, das analytische und kreative Prozesse miteinander verknüpft. Anhand eines strukturierten Artikulationsschemas werden die Zielsetzungen, Verlaufsphasen und didaktischen Anforderungen des Verfahrens beschrieben. Abschließend wird aufgezeigt, wie Designanalysen zur Entwicklung gestalterischer Urteilskompetenz beitragen und Lernende befähigen, Designentscheidungen reflektiert zu begründen und in handlungsorientierten Lernsituationen weiterzuführen.
This article presents design analysis as a design-oriented instructional approach in vocational education and training. Design analysis is understood as a systematic method for examining, evaluating, and further developing design and product characteristics, integrating analytical and creative processes. Using a structured instructional framework, the article outlines the objectives, phases, and didactic requirements of the approach. It concludes by demonstrating how design analysis contributes to the development of design-related judgement and enables learners to reflect on and justify design decisions, transferring them into action-oriented learning contexts
Water storage paradox of reservoir expansion and evaporative losses in the MENA region
No full textProlonged droughts and population growth have increased the demand for efficient water storage globally. Small agricultural reservoirs support local water demands, but high evaporation rates particularly in dry regions undermine their storage effectiveness. Integrating fine-resolution Sentinel-2 imagery and physical modeling, we created an annual dataset of small agricultural reservoirs (< 0.1 km2) in the Middle East and North Africa (MENA) and quantified their associated evaporative losses from 2016 to 2023. We identified over 133,700 reservoirs, peaking in 2020, providing a combined surface area of 1,408 km2. The largest cumulative areas are located in Türkiye (309 km2), Pakistan (234 km2), Iran (168 km2), Iraq (108 km2), and Egypt (64 km2). Small agricultural reservoirs offer a storage capacity of 1,243 million cubic meters, accounting for up to 16% of irrigation and livestock water use in most MENA countries. Annual evaporative losses from these reservoirs may potentially exceed 2,400 million cubic meters with hotspots of cumulative evaporation corresponding to regions with the highest reservoir surface area, including southern Pakistan, southwestern Iran, and southeastern Iraq. Our analysis suggests strong climatic and anthropogenic influences on the expansion of reservoirs and their storage efficiency emphasizing the need for mitigation strategies to improve agricultural water security in water-stressed regions
3D printed embolization module for treatment training of chronic subdural hematomas in interventional neuroradiology
No full textMinimally invasive techniques have revolutionized the treatment of cerebrovascular disease, including middle meningeal artery embolization (MMAE) as a promising alternative to open surgical treatment of chronic subdural hematoma (cSDH). However, training in MMAE still requires the use of animal models, which have ethical concerns and are not anatomically realistic. This study presents the development of a 3D printed, interchangeable MMA embolization module for integration into the HANNES neurointerventional simulator with the previously developed MMA model to enable realistic simulation of cSDH treatment with the liquid embolic agent Onyx. The module was designed in a patient-like geometry and manufactured using stereolithography (SLA) printing with two different materials. A detailed evaluation of the manufacturing parameters showed that the choice of material and print orientation had a significant impact on post-processing efficiency. The final module was tested in a realistic angiography suite with original treatment instruments and its performance was evaluated by experienced neuroradiologists. The module received high marks for anatomical realism, flow characteristics and embolic agent distribution. The results highlight the potential of the module as an effective tool for neurointerventional training, reducing the need for animal models while providing a standardized, reproducible training platform. Future work could focus on integrating the module into structured training courses, exploring its application for radiation-free learning due to its transparency, and incorporating objective evaluation metrics to assess procedural performance and skill acquisition
Breaking barriers: the role of external innovation support in enhancing media organisations’ innovation processes
No full textIn recent years, external support for journalism innovation has grown, driven by public, private, and philanthropic actors, such as governments, tech companies and foundations. This paper analyses how these supporters assist media organisations in overcoming common challenges and barriers in their innovation processes. Using the German WPK Innovation Fund as a unique research setting, it adopts a qualitative longitudinal multiple-case study approach combining interviews, document analysis and observations to examine 20 innovation ventures in journalism. Findings show that such support can play a pivotal role for media organisations, particularly at the meso level of organisational challenges. The paper provides a framework for future research to analyse other support structures more systematically and holds practical implications for all parties designing and improving them.Bundesministerium für Forschung, Technologie und Raumfahrt (BMFTR
Effects of climate change on coastal hydrodynamics along the German Baltic Sea coast
No full textThe German federal state of Schleswig-Holstein is developing a Baltic Sea Coast 2100 strategy under the leadership of the Ministry for Energy Transition, Climate Protection, Environment and Nature. The aim of the strategy is a sustainable adaptation of the coastal region to climate change, taking into account the demands of nature conservation, tourism and coastal protection. Basis for this strategy is detailed information on the current status and possible future changes in coastal hydrodynamics and sediment dynamics, including morphological changes. In a joint research project from 2019 to 2023, the Institute of River and Coastal Engineering of Hamburg University of Technology (TUHH) carried out model-based investigations to describe and analyze currents and transport processes along the entire Baltic Sea coast of Schleswig-Holstein (greater than 400 km) for the current state as well as for possible future conditions, taking into account various scenarios for sea level rise and climate change-induced changes of wind conditions
MnTiO₃ as a carbon-free cathode for rechargeable Li–O₂ batteries
No full textLi-O2 batteries (LOBs) are next-generation energy storage systems. However, their main challenges are the sluggish kinetics of oxygen reduction and evolution reactions (ORR/OER) and high charge overpotentials due to the formation of discharge product (Li2O2). To address this challenge, developing a catalyst with a unique structure and exceptional catalytic properties is crucial to enhancing the reversible cycling performance of LOBs, particularly under high current density conditions. Herein, the transition metal-based perovskite MnTiO3 was examined as a carbon-free cathode catalyst using density functional theory (DFT) calculations and experimental techniques. The intrinsic advantages of MnTiO3 stem from the coexistence of Mn and Ti energy levels near the Fermi level, as revealed by our density of states (DOS) analysis. This electronic structure facilitates ORR/OER, thus endowing MnTiO3 with a bifunctional role in promoting battery performance. Our DFT-based investigation elucidates the surface stability and catalytic properties of MnTiO3. Furthermore, Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) confirm that the electrochemical reaction on MnTiO3 follows a two-electron pathway. Our findings reveal that a LOB with MnTiO3 exhibits a total overpotential of 1.18 V and 1.55 V using DFT and electrochemical measurements, respectively. High current densities up to 1 A g−1 also highlight its potential as a cathode catalyst for LOBs