Refine
Year of publication
Document Type
- Article (22) (remove)
Has Fulltext
- yes (22) (remove)
Keywords
- Einspielen <Werkstoff> (3)
- Air purification (1)
- Alternating plasticity (1)
- Analysis (1)
- Analytischer Zulaessigkeitsnachweis (1)
- Arthosetherapie (1)
- Aufschlagversuch (1)
- Axialbelastung (1)
- Axially cracked pipe (1)
- Bacterial cellulose (1)
- Bioreaktor (1)
- Blutzellenlagerung (1)
- Bone quality and biomechanics (1)
- Carbon sources (1)
- Cellulose nanostructure (1)
- Cement infiltration (1)
- Clusterion (1)
- Cost-effectiveness (1)
- Culture media (1)
- Deformation (1)
- Design-by-analysis (1)
- Druckbeanspruchung (1)
- Druckbehälter (1)
- Druckbelastung (1)
- Einspiel-Analyse (1)
- Einspiel-Kriterium (1)
- Einspielen (1)
- Environmental impact (1)
- Epithel (1)
- Experiment (1)
- FEM (1)
- Fehlerstellen (1)
- Fibroblast (1)
- Finite-Elemente-Methode (1)
- Fließgrenze (1)
- Fußball (1)
- Geriatric (1)
- Global and local collapse (1)
- Gonarthrose (1)
- Grenzwertberechnung (1)
- Harnleiter (1)
- Hemoglobin structure (1)
- Hip fractures (1)
- Hämoglobin (1)
- Hämoglobinstruktur (1)
- Kniegelenkarthrose (1)
- Knochen (1)
- Knochenbildung (1)
- Knochenchirugie (1)
- Knochendichte (1)
- Kohlenstofffaser (1)
- Limit analysis (1)
- Lipopolysaccharide (1)
- Luftreiniger (1)
- MBST (1)
- Medusomyces gisevi (1)
- Organkultur (1)
- Osteoporose (1)
- Osteoporosis (1)
- Permeability (1)
- Permeabilität (1)
- Pflanzenphysiologie (1)
- Pflanzenscanner (1)
- Pflanzenstress (1)
- Plasmacluster ion technology (1)
- Plastizität (1)
- Pressure loaded crack-face (1)
- Prevention (1)
- Progressive plastic deformation (1)
- Prophylaxis (1)
- Ratchetting (1)
- Raumluft (1)
- Red blood cell storage (1)
- Rohr (1)
- Rohrbruch (1)
- Schienbeinschoner (1)
- Schwammknochen (1)
- Shakedown (1)
- Shakedown analysis (1)
- Shakedown criterion (1)
- Skeletal muscle (1)
- Small Aral Sea (1)
- Stahl (1)
- Strukturanalyse (1)
- Temperaturabhängigkeit (1)
- Tendons (1)
- Tissue Engineering (1)
- Traglastanalyse (1)
- Ultrasound (1)
- Vertebroplastie (1)
- Vertebroplasty (1)
- Viscous flow (1)
- Viskose Strömung (1)
- Viskosität (1)
- Wolff's Law (1)
- Wolffsches Gesetz (1)
- Wundheilung (1)
- Zug-Druck Belastung (1)
- alternierend Verformbarkeit (1)
- arthrosis therapy (1)
- bone density (1)
- bone structure (1)
- burst pressure (1)
- burst tests (1)
- cancellous bone (1)
- carbonized rice husk (1)
- ecological structure (1)
- epithelization (1)
- flaw (1)
- fortschreitende plastische Deformation (1)
- gonarthrosis (1)
- human dermal fibroblasts (1)
- lipopolysaccharides (1)
- load limit (1)
- metagenomics (1)
- microbial diversity (1)
- nanostructured carbonized plant parts (1)
- nanostrukturierte carbonisierte Pflanzenteile (1)
- pipes (1)
- plant scanner (1)
- plant stress (1)
- ratchetting (1)
- shakedown (1)
- shakedown analysis (1)
- shotgun sequencing (1)
- tension–torsion loading (1)
- vessels (1)
- wound healing (1)
- yield stress (1)
Institute
- IfB - Institut für Bioengineering (22) (remove)
Plant physiology and plant stress: Plant physiology will be much more important for human mankind because of yield and cultivation limits of crops determined by their resistance to stress. To assess and counteract various stress factors it is necessary to conduct plant research to gain information and results on plant physiology.
Microbial diversity studies regarding the aquatic communities that experienced or are experiencing environmental problems are essential for the comprehension of the remediation dynamics. In this pilot study, we present data on the phylogenetic and ecological structure of microorganisms from epipelagic water samples collected in the Small Aral Sea (SAS). The raw data were generated by massive parallel sequencing using the shotgun approach. As expected, most of the identified DNA sequences belonged to Terrabacteria and Actinobacteria (40% and 37% of the total reads, respectively). The occurrence of Deinococcus-Thermus, Armatimonadetes, Chloroflexi in the epipelagic SAS waters was less anticipated. Surprising was also the detection of sequences, which are characteristic for strict anaerobes—Ignavibacteria, hydrogen-oxidizing bacteria, and archaeal methanogenic species. We suppose that the observed very broad range of phylogenetic and ecological features displayed by the SAS reads demonstrates a more intensive mixing of water masses originating from diverse ecological niches of the Aral-Syr Darya River basin than presumed before.
Diese Studie beschäftigte sich mit der Dämpfungswirkung von Schienbeinschonern, wie sie beim Fußball zum Einsatz kommen. Sie wurde mit Hilfe eines Pendelhammers durchgeführt, der verschiedene Aufschlagkräfte auf die Schoner ermöglichte. Dabei wurde deutlich, dass Schienbeinschoner die beste Wirkung bei Maximalkräften unterhalb von 5kN erreichen können, dass bei größerer Belastung allerdings Verbesserungsbedarf besteht. Hierfür konnte, u.a. durch den Einsatz neuer Materialien, ein guter Ansatzpunkt im „adäquaten Zusammenspiel von Schale und Polsterung“ der Schoner gefunden werden. Die Untersuchung hat weiterhin gezeigt, dass zumindest teilweise eine deutliche Verbesserung der Dämpfungswirkung der Schienbeinschoner in den letzten Jahren erreicht werden konnte.
The international partnership of space agencies has agreed to proceed forward to the Moon sustainably. Activities on the Lunar surface (0.16 g) will allow crewmembers to advance the exploration skills needed when expanding human presence to Mars (0.38 g). Whilst data from actual hypogravity activities are limited to the Apollo missions, simulation studies have indicated that ground reaction forces, mechanical work, muscle activation, and joint angles decrease with declining gravity level. However, these alterations in locomotion biomechanics do not necessarily scale to the gravity level, the reduction in gastrocnemius medialis activation even appears to level off around 0.2 g, while muscle activation pattern remains similar. Thus, it is difficult to predict whether gastrocnemius medialis contractile behavior during running on Moon will basically be the same as on Mars. Therefore, this study investigated lower limb joint kinematics and gastrocnemius medialis behavior during running at 1 g, simulated Martian gravity, and simulated Lunar gravity on the vertical treadmill facility. The results indicate that hypogravity-induced alterations in joint kinematics and contractile behavior still persist between simulated running on the Moon and Mars. This contrasts with the concept of a ceiling effect and should be carefully considered when evaluating exercise prescriptions and the transferability of locomotion practiced in Lunar gravity to Martian gravity.
Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.
In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter’s moon Europa and Saturn’s moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find life, if it exists. Technologically, such missions are extremely challenging. The required key technologies include power generation, communications, pressure resistance, radiation hardness, corrosion protection, navigation, miniaturization, autonomy, and sterilization and cleaning. Simpler mission concepts involve impactors and penetrators or – in the case of Enceladus – plume-fly-through missions.
Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions.
Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data.
Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.
The most of conventional methods of air purification use the power of a fan to draw in air and pass it through a filter. The problem of bacterial contamination of inner parts of such a type of air conditioners in some cases draws attention towards alternative air-cleaning systems. Some manufacturers offer to use the ozone's bactericidal and deodorizing effects, but the wide spreading of such systems is restricted by the fact that toxic effects of ozone in respect of human beings are well known. In 2000 Sharp Inc. introduced "Plasma Cluster Ions (PCI)" air purification technology, which uses plasma discharge to generate cluster ions (I 0-14 ). This technology has been developed for those customers that are conscious about health and hygiene. In our experiments, we focused on some principal aspects of plasma-generated ions application - time-dependency and irreversibility of bactericidal action, spatial and kinetic characteristics of emitted cluster particles, their chemical targets in the microbial cells.