Experimentelle Ermittlung von Bauteilbelastungen eines Power Tool Antriebsstrangs durch indirektes Messen in realitätsnahen Anwendungen als ein Baustein in der Teilsystemvalidierung

This article shows by experimental studies on angle grinders, how application-equivalent stresses on the components can be determined. For this purpose a distance measurement technique is applied with which the movement of the shaft is detected while the angle grinder is in operation. The research results support validation activities in product development and contribute to early validation. It helps to analyzing the dynamic and working life of the power tool and therefore construction targets are derived. The related applications are considered and power tools with measuring equipment in the lab are tested. The measurement results are presented and possible causes and effects on the life of the components are discussed. With the method of investigation it is possible to study the behavior of subsystems already in development phases in which the overall system is not physically present.     

Classification of Amyloidosis by Model-Assisted Mass Spectrometry-Based Proteomics

Amyloidosis is a rare disease caused by the misfolding and extracellular aggregation of proteins as insoluble fibrillary deposits localized either in specific organs or systemically throughout the body. The organ targeted and the disease progression and outcome is highly dependent on the specific fibril-forming protein, and its accurate identification is essential to the choice of treatment. Mass spectrometry-based proteomics has become the method of choice for the identification of the amyloidogenic protein. Regrettably, this identification relies on manual and subjective interpretation of mass spectrometry data by an expert, which is undesirable and may bias diagnosis. To circumvent this, we developed a statistical model-assisted method for the unbiased identification of amyloid-containing biopsies and amyloidosis subtyping. Based on data from mass spectrometric analysis of amyloid-containing biopsies and corresponding controls. A Boruta method applied on a random forest classifier was applied to proteomics data obtained from the mass spectrometric analysis of 75 laser dissected Congo Red positive amyloid-containing biopsies and 78 Congo Red negative biopsies to identify novel “amyloid signature” proteins that included clusterin, fibulin-1, vitronectin complement component C9 and also three collagen proteins, as well as the well-known amyloid signature proteins apolipoprotein E, apolipoprotein A4, and serum amyloid P. A SVM learning algorithm were trained on the mass spectrometry data from the analysis of the 75 amyloid-containing biopsies and 78 amyloid-negative control biopsies. The trained algorithm performed superior in the discrimination of amyloid-containing biopsies from controls, with an accuracy of 1.0 when applied to a blinded mass spectrometry validation data set of 103 prospectively collected amyloid-containing biopsies. Moreover, our method successfully classified amyloidosis patients according to the subtype in 102 out of 103 blinded cases. Collectively, our model-assisted approach identified novel amyloid-associated proteins and demonstrated the use of mass spectrometry-based data in clinical diagnostics of disease by the unbiased and reliable model-assisted classification of amyloid deposits and of the specific amyloid subtype.     

Obstacles for cognitive analogy in analysis and synthesis in microsystems development

In most cases, product development is not inventing a product completely new and from scratch, it typically either adds a few newly developed sub-functions to mainly known sub-functions, or it generates invention based on new combinations of already existing and slightly modified sub-functions. This synthesis is ideally based on a preceding and comprehensive system analysis that is necessary to define promising directions for advancement in further product development. In analysis as well as in synthesis the design engineer needs creativity—either to be able to recognize which functions are realized in a given system that is subject to analysis or to be able to think up new ways how a desired function could be realized in a system. The main cognitive mechanism for creativity is analogy and this mechanism in turn is based on schemas and mental models. In microsystems development, micro specific obstacles accrue when using analogies. In this work, the authors derive the nature and source of these obstacles and their implications on microsystems development. To overcome these obstacles, a functions catalogue is proposed. This catalogue can directly be used to add an external source for analogies during system synthesis. By transferring a method called geometrical similarity search to microsystems technology and combining it with the functions catalogue, system analysis can be supported as well.     

User-centered design of power tools: a generic process for evaluation of usability aspects

Forschung im Ingenieurwesen - User-centered design focuses on the individual needs of the product users. The aim is to adjust the design of the product according to the requirements of the user and...     

Electrolyte‐Gated n‐Type Transistors Produced from Aqueous Inks of WS2 Nanosheets

Solution‐processed, low cost thin films of layered semiconductors such as transition metal dichalcogenides (TMDs) are potential candidates for future printed electronics. Here, n‐type electrolyte‐gated transistors (EGTs) based on porous WS₂ nanosheet networks as the semiconductor are demonstrated. The WS₂ nanosheets are liquid phase exfoliated to form aqueous/surfactant stabilized inks, and deposited at low temperatures (T < 120 °C) in ambient atmosphere by airbrushing. No solvent exchange, further additives, or complicated processing steps are required. While the EGTs are primarily n‐type (electron accumulation), some hole transport is also observable. The EGTs show current modulations > 10⁴ with low hysteresis, channel width‐normalized on‐conductances of up to 0.27 µS µm^?1 and estimated electron mobilities around 0.01 cm² V^?1 s^?1. In addition, the WS₂ nanosheet networks exhibit relatively high volumetric capacitance values of 30 F cm^?3. Charge transport within the network depends significantly on the applied lateral electric field and is thermally activated, which supports the notion that hopping between nanosheets is a major limiting factor for these networks and their future application.     

Investigation of the thread coefficient of friction when impact tightening bolted joints

Forschung im Ingenieurwesen - The friction conditions in bolted joints are decisive for the quality of the tightening process and therefore for the quality of the joint. One of the many influences...     

Tracking mesenchymal stem cells with iron oxide nanoparticle loaded poly(lactide-co-glycolide) microparticles

Monitoring the location, distribution and long-term engraftment of administered cells is critical for demonstrating the success of a cell therapy. Among available imaging-based cell tracking tools, magnetic resonance imaging (MRI) is advantageous due to its noninvasiveness, deep penetration, and high spatial resolution. While tracking cells in preclinical models via internalized MRI contrast agents (iron oxide nanoparticles, IO-NPs) is a widely used method, IO-NPs suffer from low iron content per particle, low uptake in nonphagocytotic cell types (e.g., mesenchymal stem cells, MSCs), weak negative contrast, and decreased MRI signal due to cell proliferation and cellular exocytosis. Herein, we demonstrate that internalization of IO-NP (10 nm) loaded biodegradable poly(lactide-co-glycolide) microparticles (IO/PLGA-MPs, 0.4-3 μm) in MSCs enhances MR parameters such as the r(2) relaxivity (5-fold), residence time inside the cells (3-fold) and R(2) signal (2-fold) compared to IO-NPs alone. Intriguingly, in vitro and in vivo experiments demonstrate that internalization of IO/PLGA-MPs in MSCs does not compromise inherent cell properties such as viability, proliferation, migration and their ability to home to sites of inflammation.     

A method for estimating solid organ donor potential by organ procurement region

OBJECTIVES: This study sought to develop a methodology for estimating potential solid organ donors and measuring donation performance in a geographic region based on readily available data on the hospitals in that region. METHODS: Medical records were reviewed in a stratified random sample of 89 hospitals from 3 regions to attain a baseline of donor potential. Data on a range of hospital characteristics were collected and tested as predictors of donor potential through the use of hierarchical Poisson regression modeling. RESULTS: Five hospital characteristics predicted donor potential: hospital deaths, hospital Medicare case-mix index, total hospital staffed beds, medical school affiliation, and trauma center certification. Regional estimates were attained by aggregating individual hospital estimates. Confidence intervals for these regional estimates indicated that actual donations represented from 28% to 44% of the potential in the regions studied. CONCLUSIONS: This methodology accurately estimates organ donor potential within 3 geographic regions and lays the foundation for evaluating organ donation effectiveness nationwide. Additional research is needed to test the validity of the model in other geographic regions and to further explore organ donor potential in hospitals with fewer than 50 beds.     

Multisecular corrosion behaviour of low carbon steel in anoxic soils: Characterisation of corrosion system on archaeological artefacts

In the context of the prediction of materials behaviour used in the nuclear waste storage, the understanding of iron corrosion mechanisms in anoxic environment is of great importance. Information can be obtained using complementary analytical tools. Interactions between burial soil and archaeological artefacts are studied by performing on site soil measurements. Moreover, archaeological artefacts are studied on transverse sections using a combination of microbeam techniques. The specific interest of this project lies in the study of ferrous thick corrosion layers formed in anoxic environments.