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- Elektrochemie (3)
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- model car (2)
- Ableitung Solltrajektorie (1)
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In our present paper, we approach the mixed problem with initial and boundary conditions, in the context of thermoelasticity without energy dissipation of bodies with a dipolar structure. Our first result is a reciprocal relation for the mixed problem which is reformulated by including the initial data into the field equations. Then, we deduce a generalization of Gurtin’s variational principle, which covers our generalized theory for bodies with a dipolar structure. It is important to emphasize that both results are obtained in a very general context, namely that of anisotropic and inhomogeneous environments, having a center of symmetry at each point.
This study is concerned with the linear elasticity theory for bodies with a dipolar structure. In this context, we approach transient elastic processes and the steady state in a cylinder consisting of such kind of body which is only subjected to some boundary restrictions at a plane end. We will show that at a certain distance d=d(t), which can be calculated, from the loaded plan, the deformation of the body vanishes. For the points of the cylinder located at a distance less than d, we will use an appropriate measure to assess the decreasing of the deformation relative to the distance from the loaded plane end. The fact that the measure, that assess the deformation, decays with respect to the distance at the loaded end is the essence of the principle of Saint-Venant.
Diese Arbeit beschreibt die Aufstellung einer Trajektorie für ein autonomes Fahrzeug. Als Basis dient eine Vorarbeit, bei der ein neuronales Netz das Bild einer Frontkamera eines Autos in Fahrspur und Nicht-Fahrspur segmentiert. Darauf aufbauend wird das Bild zunächst in die Vogelperspektive transformiert. Anschließend folgen eine Detektion der Fahrspurkanten sowie ein Clustering-Verfahren, um linke und rechte Kantenabschnitte zu separieren. Weiter wird die Trajektorie diskret in Form von Parametern des Kreisbogenmodells aufgenommen. Die Prädiktion dieser Parameter erfolgt mittels eines Extended Kalman-Filters. Die abschließende Validierung der Algorithmen erfolgt durch eine synthetisch generierte Fahrspur.
Additive manufacturing offers unique possibilities to produce complex components, which would not be possible or only very difficult to be realizable with conventional manufacturing processes. The potential of additive manufacturing of aluminum alloys has already been realized in prototyping, but still offers potential in the establishment of series applications. For enabling the establishment of additive manufacturing in series applications, comprehensive knowledge about the material behavior is necessary. This study examines the torsional behavior of additive manufactured AlSi10Mg samples and shows the correlation between tensile and torsional strength. Comprehensive torsion tests with strain gauges were performed and significant directional dependencies were shown. The correlation factor in the area of torsional yield strength/tensile yield strength and torsional strength/tensile strength was determined and was compared with the yield/failure conditions according to Tresca and von Mises.
Herein, the general constitutive equation of bi-phasic materials equipped with orientation tensor is presented in direct notation. The formulation is refined by some correction factors specific to natural fibre-reinforced composites; then, a planar case is derived. The necessity of local information is emphasised through the introduction of auxiliary maps, which included volume fraction and orientation data. A semi-analytical homogenisation method is introduced through finite element analysis. Auxiliary maps are shown to be a better alternative to the overall orientation of fibres. Global calculations are insensitive to local variations whilst appropriate auxiliary maps offer refined results. Considering the multidisciplinary application of orientation tensors, the proposed scheme can be used in all areas where local information cannot be disregarded.
Analyse der Wirksamkeit des Harninkontinenzmanagements in einer geriatrischen Rehabilitationsklinik
(2020)
Chances and risks of industry 4.0 for quality assurance - empirical study on companies in the german manufacturing industry. The increasing complexitiy of products as well as the trend to more individualized products lay down enormous tasks on the manufacturing industry. They can only be managed by using industry 4.0 methods. In this context, digitization is implemented in quality assurance, too - fostering a significant increase in product and process quality. The presendt study reveals the current state of digitalization and the opportunities and challenges associated with it - in the view of experts and decision makers of the manufacturing industry.
Comparing multidimensional sensor data from vehicle fleets with methods of sequential data mining
(2020)
Electrochemical strain microscopy (ESM) is a powerful atomic force microscopy (AFM) mode for the investigation of ion dynamics and activities in energy storage materials. Here we compare the changes in commercial LiFePO4 cathodes due to ageing and its influence on the measured ESM signal. Additionally, the ESM signal dynamics are analysed to generate characteristic time constants of the diffusion process, induced by a dc-voltage pulse, which changes the ionic concentration in the material volume under the AFM tip. The ageing of the cathode is found to be governed by a decrease of the electrochemical activity and the loss of available lithium for cycling, which can be stored in the cathode.
Für das autonome Fahren ist es notwendig, Verfahren zu entwickeln, die in der Lage sind, die Position und die Orientierung von Objekten zu ermitteln. Eine große Herausforderung ist die Zuordnung der durch Sensoren erfassten Messpunkten zu Objekten und die notwendige Validierung dieser Daten. In diesem Beitrag wird die Datenassoziation von Messpunkten zu einem Objekt mittels Künstlicher Intelligenz (KI) untersucht. Hierbei wird ein Neuronales Netz verwendet, welches die Zuordnung der Messpunkte zu einem bestimmten Objekt übernimmt oder diese als Rauschen deklariert. Es wird untersucht wie sich die Performance von Long Short-Term Memory (LSTM)-Layern gegenüber Dense-Layern für diesen Einsatz-Zweck verhält. Die verwendeten Daten werden mittels einer 2D-Simulation erzeugt. Der Output des Neuronalen Netzes wird verwendet, um die Trajektorien mehrerer Objekte zu erfassen und deren zukünftige Bewegung durch einen Kalman-Filter vorherzusagen.
Mobilitätshilfen sind allgegenwärtig und existenziell für Menschen, die aufgrund von Krankheit und Pflegebedürftigkeit in ihren Alltagsbewegungen und -fortbewegungen eingeschränkt sind. Mobilität steht in einem direkten Zusammenhang zur Selbstständig-keit und Selbstbestimmung im Alltag. Für viele pflegebedürftige Menschen sind Mobili-tätshilfen entscheiden dafür, ob sie ihren Alltag (wieder) selbst gestalten können. Dabei müssen sie sich innerhalb und außerhalb von Räumen ganz unterschiedlichen Heraus-forderungen stellen. Teilhabe am sozialen, möglicherweise auch am beruflichen Leben wird für viele Betroffene erst dann möglich, wenn die unterschiedlichen Mobilitätshilfen aufeinander und auf die jeweiligen Aktivitäten abgestimmt sind. Für Angehörige und für Pflegefachpersonen stellt sich täglich die Frage, mit welchen Mobilitätshilfen eine siche-re und angemessene Unterstützung möglich ist. Dabei gilt es, die Ausstattung mit Hilfen dem aktuellen Mobilitätsprofil der Betroffenen anzupassen; die Folgen von Über- oder Unterversorgung mit Mobilitätshilfen kann für die Betroffenen gravierende negative Folgen haben!
Der sächsische Volkseinwand
(2020)
Design of a transverse controller for an autonomous driving model car based on the Stanley approach
(2020)
The Stanley approach is an established transverse controller
for autonomous vehicle’s to follow a desired reference
path accordingly. In this publication, functional extensions of
the Stanley algorithm are demonstrated. The resulting overall
lateral controller can be used for autonomous model cars
especially.
Drug-induced liver toxicity is one of the most common reasons for the failure of drugs in clinical trials and frequent withdrawal from the market. Reasons for such failures include the low predictive power of in vivo studies, that is mainly caused by metabolic differences between humans and animals, and intraspecific variances. In addition to factors such as age and genetic background, changes in drug metabolism can also be caused by disease-related changes in the liver. Such metabolic changes have also been observed in clinical settings, for example, in association with a change in liver stiffness, a major characteristic of an altered fibrotic liver. For mimicking these changes in an in vitro model, this study aimed to develop scaffolds that represent the rigidity of healthy and fibrotic liver tissue. We observed that liver cells plated on scaffolds representing the stiffness of healthy livers showed a higher metabolic activity compared to cells plated on stiffer scaffolds. Additionally, we detected a positive effect of a scaffold pre-coated with fetal calf serum (FCS)-containing media. This pre-incubation resulted in increased cell adherence during cell seeding onto the scaffolds. In summary, we developed a scaffold-based 3D model that mimics liver stiffness-dependent changes in drug metabolism that may more easily predict drug interaction in diseased livers.
Die Bedeutung der Digitalisierung für Berufliche Bildung und Fachkräftesicherung in der Pflege
(2020)
Die Perspektive wechseln
(2020)
Mithilfe des Konzepts der gesundheitlichen Versorgungsplanung – auch als Advance Care Planning (ACP) oder „Behandlung im Voraus planen“ (BVP) bekannt – sollen Behandlungsziele fest gelegt werden, und zwar für den Fall, dass der Betroffene seinen Willen nicht äußern kann. Neben der individuellen Gesprächsbegleitung spielen in diesem Zusammenhang auch Fall- besprechungen eine wichtige Rolle. Diese sind zwar gesetzlich vorgesehen, jedoch fehlt bislang eine einheitliche Struktur, an der sich Fachkräfte in der Praxis orientieren können.
A number of planetary boundaries, including climate change as a result of greenhouse gas emissions, has already been exceeded. This situation has deleterious consequences for public health. Paradoxically, 4.4% of these emissions are attributable to the healthcare sector. These problems have not been sufficiently acknowledged in health professions curricula. This paper addresses two main issues, humanistic learning and the application of knowledge acquisition to clinical practice. Humanistic learning principles can be used to emphasize learner-centered approaches, including knowledge acquisition and reflection to increase self-awareness. Applying humanistic principles in everyday life and clinical practice can encourage stewardship, assisting students to become agents for change. In terms of knowledge and skills application to clinical practice, an overview of varied and novel approaches of how sustainable education can be integrated at different stages of training across several health care professions is provided. The Health and Environment Adaptive Response Taskforce (HEART) platform as an example of creating empowered learners, the NurSusTOOLKIT, a multi-disciplinary collaboration offering free adaptable educational resources for educators and the Greener Anaesthesia and Sustainability Project (GASP), an example of bridging the transition to clinical practice, are described.
Effect of voids in a heat-flux dependent theory for thermoelastic bodies with dipolar structure
(2020)
The moisture absorption behavior of flax fiber-reinforced epoxy composites is deliberated to be a serious issue. This property restricts their usage as outdoor engineering structures. Therefore, this study provides an investigation of moisture in flax fibers on the performance of the flax/epoxy composite materials based on their shear responses. The ±45° aligned flax fibers exposed to different relative humidities (RH) and the vacuum infusion process was used to manufacture the composite specimens. The optimum shear strength (40.25 ± 0.75 MPa) was found for the composites manufactured with 35% RH-conditioned flax fibers, but the shear modulus was reduced consistently with increasing RH values. Although shear strength was increased because of fiber swelling with increased moisture absorption rate until 35% RH environments with good microstructures, nonetheless, strength and modulus both started to decrease after this range. A very poor microstructure has been affirmed by the SEM images of the composite samples conditioned at 90% RH environments.
Das Interesse der Industrie an additiv gefertigten Bauteilen steigt z unehmend, wobei mit zunehmendem Verständnis der statischen Kennwerte nunmehr der Fokus in Richtung der dynamischen Festigkeiten wandert. Deswegen werden Einflussparameter auf die Lebensdauer und potenzielle Nachbearbeitungsmethoden untersucht und analysiert. Ein großer Einfluss ist dabei der Oberflächengüte und den durch Rautiefen initiierten Kerbeffekten zuzuschreiben. Deswegen werden unterschiedliche Methoden zur Verbesserung der Oberflächengüte untersucht. Dabei werden die Verfahren Laserpolieren, elektrochemisches Polieren und Hartmetallkugelstrahlen und deren Auswirkung auf Oberflächengüte sowie Härte untersucht. Für das elektrochemische Polieren werden die Proben in einer Perchlorsäure für 90 s bei 32 V und maximal 10 A poliert. Das Hartmetallkugelstrahlen wird mit einem UFS 100 Strahlmittel bei einem Druck von 4 bar und einer Strahldauer von 10 s ausgeführt. Anschließend werden Wöhlerlinien für die unterschiedlichen Zustände mittels Umlaufbiegeversuch ermittelt, welche mit Referenzwerten analysierter konventioneller Proben verglichen werden. Des Weiteren werden die Bruchflächen analysiert. Die Untersuchungen ergaben ein hohes Optimierungspotenzial der additiv gefertigten Proben bei einer Verdichtung der Oberfläche sowie einer Entfernung der Randschicht durch eine spanende Bearbeitung. Dadurch wurden höhere Zeitfestigkeiten als mit konventionell gefertigten Proben erreicht.
This paper aims to analyze the stress and strain states appearing in the elbow of a tube, such as those commonly used in a city’s water supply network. The stress field is characterized by the fact that there is a significant stress increase when compared to a straight tube. As a result, the strength of such an elbow must be investigated and guaranteed for such a network to be well designed. A practical solution used is to anchor the elbow in a massive concrete block. The paper compares the stress field that occurs in the elbow when it is free, buried in the ground, and when it is anchored in a massive concrete block. Furthermore, we investigate how a crack appears and propagates in the elbow. This happens especially for the elbow buried in the ground where the stress and strain are higher than when the elbow is anchored in concrete. The results obtained can be used in the current practice in the case of water supply networks made by high-density polyethylene pipes.
The aim of the current work was to illustrate the effect of the fibre area correction factor on the results of modelling natural fibre-reinforced composites. A mesoscopic approach is adopted to represent the stochastic heterogeneity of the composite, i.e. a meso-structural numerical model was prototyped using the finite element method including quasi-unidirectional discrete fibre elements embedded in a matrix. The model was verified by the experimental results from previous work on jute fibres but is extendable to every natural fibre with cross-sectional non-uniformity. A correction factor was suggested to fine-tune both the analytical and numerical models. Moreover, a model updating technique for considering the size-effect of fibres is introduced and its implementation was automated by means of FORTRAN subroutines and Python scripts. It was shown that correcting and updating the fibre strength is critical to obtain accurate macroscopic response of the composite when discrete modelling of fibres is intended. Based on the current study, it is found that consideration of the effect of flaws on the strength of natural fibres and inclusion of the fibre area correction factor are crucial to obtain realistic results.
Laser powder bed fusion has become one of the major techniques within metal additive manufacturing, especially when delicate structures and high geometric accuracy are concerned. Lately, the awareness of the material-specific macroscopic anisotropy has risen and led to widespread investigations on the static mechanical strength. However, little is known about the fracture behavior of the layer-wise fabricated metal components and their affinity of crack propagation between consecutive layers, which is particularly important for aluminium–silicon alloys containing embrittled zones in double-irradiated areas. A recent study indicated that there is a significant drop in fracture toughness in case the crack growth direction is parallel to the layering. To investigate this matter further and to shed light on the fracture toughness behavior in the range of a 0°–45° angle offset between the crack growth direction relative to the layering, notched samples with varying polar angles were subjected to mode I fracture toughness testing. Our results indicate that the fracture toughness is an almost-stable characteristic up to a mismatch of about 20° between the crack propagation path and the layering, at which point the fracture toughness decreases by up to 10%.
Laser powder-bed fusion (LPBF) has significantly gained in importance and has become one of the major fabrication techniques within metal additive manufacturing. The fast cooling rates achieved in LPBF due to a relatively small melt pool on a much larger component or substrate, acting as heat sink, result in fine-grained microstructures and high oversaturation of alloying elements in the α-aluminum. Al-Si-Mg alloys thus can be effectively precipitation hardened. Moreover, the solidified material undergoes an intrinsic heat treatment, whilst the layers above are irradiated and the elevated temperature in the built chamber starts the clustering process of alloying elements directly after a scan track is fabricated. These silicon-magnesium clusters were observed with atom probe tomography in as-built samples. Similar beneficial clustering behavior at higher temperatures is known from the direct-aging approach in cast samples, whereby the artificial aging is performed immediately after solution annealing and quenching. Transferring this approach to LPBF samples as a possible post-heat treatment revealed that even after direct aging, the outstanding hardness of the as-built condition could, at best, be met, but for most instances it was significantly lower. Our investigations showed that LPBF Al-Si-Mg exhibited a high dependency on the quenching rate, which is significantly more pronounced than in cast reference samples, requiring two to three times higher quenching rate after solution annealing to yield similar hardness results. This suggests that due to the finer microstructure and the shorter diffusion path in Al-Si-Mg fabricated by LPBF, it is more challenging to achieve a metastable oversaturation necessary for precipitation hardening. This may be especially problematic in larger components.
Hot isostatic pressing can be utilized to reduce the anisotropic mechanical properties of Al–Si–Mg alloys fabricated by laser powder-bed fusion (L-PBF). The implementation of post processing densification processes can open up new fields of application by meeting high quality requirements defined by aircraft and automotive industries. A gas pressure of 75 MPa during hot isostatic pressing lowers the critical cooling rate required to achieve a supersaturated solid solution. Direct aging uses this pressure related effect during heat treatment in modern hot isostatic presses, which offer advanced cooling capabilities, thereby avoiding the necessity of a separate solution annealing step for Al–Si–Mg cast alloys. Hot isostatic pressing, followed by rapid quenching, was applied to both sand cast as well as laser powder-bed fused Al–Si–Mg aluminum alloys. It was shown that the critical cooling rate required to achieve a supersaturated solid solution is significantly higher for additively manufactured, age-hardenable aluminum alloys than it is for comparable sand cast material. The application of hot isostatic pressing can be combined with heat treatment, consisting of solution annealing, quenching and direct aging, in order to achieve both a dense material with a small number of preferred locations for the initiation of fatigue cracks and a high material strength.
The objective of this study is to investigate the influence of veneering technique (hand-layering vs. milling) on the fracture resistance of bi-layer implant-supported zirconia-based hybrid-abutment crowns. Mandibular molar copings were anatomically designed and milled. Copings were then veneered by hand-layering (HL) (n = 20) and milling using the Cad-On technique (LD) (n = 20). Crowns were cemented to zirconia hybrid-abutments. Ten samples of each group acted as a control while the remaining ten samples were subjected to fatigue in a chewing simulator. Crowns were loaded between 50 and 100 N for 1.2 million cycles under simultaneous temperature fluctuation between 5 and 55 °C. Crowns were then subjected to static load a to fracture test. Data were statistically analysed using the one-way ANOVA. Randomly selected crowns from each group were observed under scanning electron microscopy to view fractured surfaces. Study results indicate that during fatigue, LD crowns had a 100% survival rate; while HL crowns had a 50% failure rate. Fracture resistance of LD crowns was statistically significantly higher than that of HL crowns at the baseline and after fatigue (p ≤ 0.05). However, fatigue did not cause a statistically significant reduction in fracture resistance in both LD and HL groups (p > 0.05). Copings fractured in the LD crowns only and the fracture path was different in both LD and HL groups. According to the results, it was concluded that milled veneer implant-supported hybrid-abutment crowns exhibit significantly higher fracture resistance, and better withstand clinical masticatory loads in the posterior region compared to the hand-layered technique. Also, fatigue application and artificial aging caused no significant strength reduction in both techniques. Clinical significance: Different veneering techniques and materials (hand-layering or milling) act differently to clinical forces and environment and may be prone to early chipping during service. Therefore, practitioners are urged to consider the appropriate veneering protocol for posterior implant-supported hybrid-abutment restorations.
This paper uses several techniques to monitor the ageing of commercial LiFePO4 cells, which are cycled at 55 °C and −20 °C at various depths of discharge. Ageing at lower depth of discharge leads to higher capacity fading, as compared to higher depth of discharge. The highest capacity fading is observed using 50% depth of discharge for cycling at 55 °C, while the lowest capacity fading is observed for the cells aged at 100% depth of discharge when cycled at −20 °C. Using incremental capacity analysis and differential voltage analysis the capacity fading is monitored and underlying ageing mechanisms are described. The loss of lithium inventory and the loss of active material, especially on the cathode side, are the major degradation mechanisms for the cells. The first incremental capacity analysis peak of the discharge process can be used in our case to predict remaining life and cell capacity.
The paper presents post-mortem analysis of commercial LiFePO4 battery cells, which are aged at 55 °C and − 20 °C using dynamic current profiles and different depth of discharges (DOD). Post-mortem analysis focuses on the structure of the electrodes using atomic force microscopy (AFM) and scanning electron microscopy (SEM) and the chemical composition changes using energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray photoelectron spectroscopy (XPS). The results show that ageing at lower DOD results in higher capacity fading compared to higher DOD cycling. The anode surface aged at 55 °C forms a dense cover on the graphite flakes, while at the anode surface aged at − 20 °C lithium plating and LiF crystals are observed. As expected, Fe dissolution from the cathode and deposition on the anode are observed for the ageing performed at 55 °C, while Fe dissolution and deposition are not observed at − 20 °C. Using atomic force microscopy (AFM), the surface conductivity is examined, which shows only minor degradation for the cathodes aged at − 20 °C. The cathodes aged at 55 °C exhibit micrometer size agglomerates of nanometer particles on the cathode surface. The results indicate that cycling at higher SOC ranges is more detrimental and low temperature cycling mainly affects the anode by the formation of plated Li.
Innovation und Qualität
(2020)
Interpretable neural networks based on continuous-valued logic and multicriteria decision operators
(2020)
Jugendhilfeplanung
(2020)
Diese Arbeit befasst sich mit der Entwicklung einer kamerabasierten Verkehrszeichenerkennung für ein autonom fahrendes Fahrzeug.
Dabei wird das neuronale Netz SSD-MobileNet-V1 verwendet, dessen Training ausschließlich mit virtuellen Trainingsdaten erfolgt. Zur Validierung wird ein autonom fahrendes Modellfahrzeug verwendet. Um die Verkehrszeichenerkennung auf dem Modellfahrzeug integrieren zu können, wird sie in Form eines ROS-Nodes implementiert, welcher außerdem die notwendige Vorverarbeitung der Kamerabilder sowie die Plausibilisierung der erkannten Verkehrszeichen beinhaltet. Es folgt die Integration der Verkehrszeichenerkennung in das Modellfahrzeug, wo sie auf einem NVIDIA Jetson TX2-Board ausgeführt wird.
Die entwickelte Verkehrszeichenerkennung ist in der Lage, 15 der 17 trainierten Verkehrszeichen zuverlässig zu erkennen und kann auf dem NVIDIA Jetson TX2-Board mit ausreichender Performance ausgeführt werden.
Diese Arbeit befasst sich mit der Entwicklung eines robusten Positionsschätzers. Die Positionsschätzung findet für einen mobilen Roboter statt, welcher autonom einen Rundkurs abfährt.
Mithilfe des von Thrun et al. entwickelte FastSLAM Ansatz wird ein Konzept zur Filterung der Position entwickelt. Geeignete Umweltinformationen werden für die kontinuierliche Korrektur ermittelt und beschrieben. Für die Korrektur wird die Charakteristik der Rennstrecke genutzt.
Durch eine Validierung des Konzepts wird die Funktionalität gezeigt und ein Einblick in die erforderliche Rechenleistung gegeben.
Lasst uns nicht alleine!
(2020)
Hintergrund
Die Prävalenz von Mangelernährung im Krankenhaus ist hoch und wird in der Praxis noch häufig unterschätzt. Im Rahmen eines vom BMBF finanzierten Projektes soll diesem Problem mithilfe von Praxiskonzepten mit präventiven und kurativen Maßnahmen für die Zielgruppe geriatrischer Patient*innen begegnet werden.
Methodik
Zur Bestimmung der Ausgangslage hinsichtlich des Ernährungsmanagements und Feststellung der aktuellen Prävalenz von Mangelernährung in zwei Stuttgarter Kliniken wurden im Rahmen des nutritionDays® spezifische Daten erhoben und mit dem Schwerpunkt auf die Zielgruppe ältere Patient*innen ausgewertet.
Ergebnisse
Von 99 eingeschlossenen Patient*innen weisen 39,4% (n=39) ein Risiko für eine Mangelernährung auf, 41 Patient*innen (41,1 %) berichten von einem ungewollten Gewichtsverlust. Der Gewichtsverlust beträgt im Mittel 6,1 kg (SD 3,8) oder 9,7% (SD 5,1) des Körpergewichtes. Nur 19,4% (n=7) der Mangelernährten erhalten eine ernährungsmedizinische Intervention. Es zeigt sich für die Gruppe mit einem hohen Mangelernährungsrisiko ein verlängerter Klinikaufenthalt von 2,1 Tagen (nicht signifikant), ein signifikant geringerer BMI (-4,3 kg/m²; p=0,001), größerer Gewichtsverlust (-12,5% vs. -3,7%; p=0,001) sowie Gewichtsveränderungen in den letzten 5 Jahren (-7,6% vs.+1,2%; p=0,004). Der ungewollte Gewichtsverlust korreliert signifikant mit der Anzahl unterschiedlicher Medikamente (rs=0,397; p=0,029) und einer verringerten Nahrungsaufnahme in der Woche vor Klinikeinweisung (rs=-0,533; p=0,003).
Schlussfolgerung
Die hohe Prävalenz von Mangelernährung unter den älteren Patient*innen bei gleichzeitig ausbleibender Identifikation der Betroffenen führt zu einer unzureichenden Behandlung der Mangelernährung. Diese Defizite lassen sich mithilfe von nutritionDay® Erhebungen deutlich aufzeigen.
Diese Arbeit stellt einen Lösungsansatz
für das Erstellen einer Karte für autonome Systeme auf Grundlage von Objekten mit Lebenspunkten vor. Dafür werden von
den Sensoren erfasste Punkte mit einem DBSCAN verarbeitet,
um zusammenhängende Cluster zu finden. Diese Cluster werden
mit Lebenspunkten versehen, welche die Existenzplausibilität
widerspiegeln.
Due to the good mechanical properties, flax fiber-reinforced epoxy composites
are being widely used as a green alternative to glass fiber composites. However,
plant fibers absorb moisture from the environment, being in a higher moisture
uptake as the relative humidity (RH) increases. This absorbed moisture deteriorates the mechanical properties of the composites. In this study, geometric
and displacement potential function (DPF) approaches are used to predict the
mechanical properties of flax fiber-reinforced epoxy composites under environmental conditions, in particular, different RH values. The tensile properties
that were measured experimentally strongly agreed with the analytical findings.
Almost similar results were found for the tensile strain those were measured
experimentally and the one predicted by the geometric function.
However, the predicted strain values were 38% and 42% less than the experimental ones for 0% and 95% RH conditioned composites, respectively, when
DPF was used. Good conformity between the experimental, analytical, and
DPF formulation for predicting mechanical properties ensures the practical
applicability of this study. The formulations established in this work could,
therefore, be utilized to analytically solve laminated composites under specific
boundary conditions in structural applications.
Slips and stumbles are main causes of falls and result in serious injuries. Balance training is widely applied for preventing falls across the lifespan. Subdivided into two main intervention types, biomechanical characteristics differ amongst balance interventions tailored to counteract falls: conventional balance training (CBT) referring to a balance task with a static ledger pivoting around the ankle joint versus reactive balance training (RBT) using externally applied perturbations to deteriorate body equilibrium. This study aimed to evaluate the efficacy of reactive, slip-simulating RBT compared to CBT in regard to fall prevention and to detect neuromuscular and kinematic dependencies. In a randomized controlled trial, 38 participants were randomly allocated either to CBT or RBT. To simulate stumbling scenarios, postural responses were assessed to posterior translations in gait and stance perturbation before and after 4 weeks of training. Surface electromyography during short- (SLR), medium- (MLR), and long-latency response of shank and thigh muscles as well as ankle, knee, and hip joint kinematics (amplitudes and velocities) were recorded. Both training modalities revealed reduced angular velocity in the ankle joint (P < 0.05) accompanied by increased shank muscle activity in SLR (P < 0.05) during marching in place perturbation. During stance perturbation and marching in place perturbation, hip angular velocity was decreased after RBT (P from TTEST, Pt < 0.05) accompanied by enhanced thigh muscle activity (SLR, MLR) after both trainings (P < 0.05). Effect sizes were larger for the RBT-group during stance perturbation. Thus, both interventions revealed modified stabilization strategies for reactive balance recovery after surface translations. Characterized by enhanced reflex activity in the leg muscles antagonizing the surface translations, balance training is associated with improved neuromuscular timing and accuracy being relevant for postural control. This may result in more efficient segmental stabilization during fall risk situations, independent of the intervention modality. More pronounced modulations and higher effect sizes after RBT in stance perturbation point toward specificity of training adaptations, with an emphasis on the proximal body segment for RBT. Outcomes underline the benefits of balance training with a clear distinction between RBT and CBT being relevant for training application over the lifespan.