Refine
Year of publication
Document Type
- Conference Proceeding (38)
- Article (22)
- Lecture (3)
Has Fulltext
- yes (63) (remove)
Keywords
- Finite-Elemente-Methode (7)
- Clusterion (5)
- Air purification (4)
- Einspielen <Werkstoff> (4)
- Hämoglobin (4)
- Limit analysis (4)
- Luftreiniger (4)
- Plasmacluster ion technology (4)
- Raumluft (4)
- Sonde (4)
- Eisschicht (3)
- Kohlenstofffaser (3)
- Lipopolysaccharide (3)
- Shakedown analysis (3)
- Technische Mechanik (3)
- lipopolysaccharides (3)
- Analytischer Zulaessigkeitsnachweis (2)
- Bruchmechanik (2)
- Einspiel-Analyse (2)
- Erythrozyt (2)
- FEM (2)
- Fibroblast (2)
- Pflanzenphysiologie (2)
- Pflanzenscanner (2)
- Shakedown (2)
- Stickstoffmonoxid (2)
- celldrum technology (2)
- nanostructured carbonized plant parts (2)
- nanostrukturierte carbonisierte Pflanzenteile (2)
- nitric oxide gas (2)
- plant scanner (2)
- ratchetting (2)
- shakedown (2)
- shakedown analysis (2)
- Adsorption (1)
- Alternating plasticity (1)
- Analysis (1)
- Anastomose (1)
- Anastomosis (1)
- Arthosetherapie (1)
- Aufschlagversuch (1)
- Autofluoreszenzverfahren (1)
- Axialbelastung (1)
- Axially cracked pipe (1)
- Bacterial cellulose (1)
- Bakterien (1)
- Biomechanics (1)
- Biomechanik (1)
- Biomedizinische Technik (1)
- Bioreaktor (1)
- Blutzellenlagerung (1)
- Bone quality and biomechanics (1)
- Carbon sources (1)
- Cellulose nanostructure (1)
- Cement infiltration (1)
- Cost-effectiveness (1)
- Culture media (1)
- Dattel (1)
- Deformation (1)
- Dekontamination (1)
- Design-by-analysis (1)
- Druckbeanspruchung (1)
- Druckbehälter (1)
- Druckbelastung (1)
- Einspiel-Kriterium (1)
- Einspielen (1)
- Elastostatics (1)
- Elektrodynamik (1)
- Endothelzelle (1)
- Environmental impact (1)
- Epithel (1)
- Exact Ilyushin yield surface (1)
- Experiment (1)
- Fehlerstellen (1)
- Finite element method (1)
- First Order Reliabiblity Method (1)
- First-order reliability method (1)
- Fließgrenze (1)
- Fußball (1)
- Geriatric (1)
- Global and local collapse (1)
- Gonarthrose (1)
- Grenzwertberechnung (1)
- Harnleiter (1)
- Hemoglobin structure (1)
- Hip fractures (1)
- Hydrodynamik (1)
- Hydrogel (1)
- Hämoglobinstruktur (1)
- Kinematics (1)
- Kinetics (1)
- Kniegelenkarthrose (1)
- Knochen (1)
- Knochenbildung (1)
- Knochenchirugie (1)
- Knochendichte (1)
- Körpertemperatur (1)
- Lichtstreuungsbasierte Instrumente (1)
- MBST (1)
- Mechanics (1)
- Mechanische Beanspruchung (1)
- Medusomyces gisevi (1)
- Natriumhypochlorit (1)
- Organkultur (1)
- Osteoporose (1)
- Osteoporosis (1)
- PFM (1)
- Permeability (1)
- Permeabilität (1)
- Pflanzenstress (1)
- Plastizität (1)
- Pressure loaded crack-face (1)
- Prevention (1)
- Progressive plastic deformation (1)
- Prophylaxis (1)
- Proteine (1)
- Random variable (1)
- Ratcheting (1)
- Ratchetting (1)
- Red blood cell storage (1)
- Rohr (1)
- Rohrbruch (1)
- Schienbeinschoner (1)
- Schwammknochen (1)
- Sensitivity (1)
- Sepsis (1)
- Shakedown criterion (1)
- Skeletal muscle (1)
- Small Aral Sea (1)
- Stahl (1)
- Statics (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)
- Wasserbrücke (1)
- Wasserstoffperoxid (1)
- Wolff's Law (1)
- Wolffsches Gesetz (1)
- Wundheilung (1)
- Zug-Druck Belastung (1)
- activated nanostructured carbon (1)
- aktivierte nanostrukturierte Kohlenstofffaser (1)
- alternierend Verformbarkeit (1)
- arthrosis therapy (1)
- autofluorescence-based detection system (1)
- bone density (1)
- bone structure (1)
- burst pressure (1)
- burst tests (1)
- cancellous bone (1)
- carbonized rice husk (1)
- contractile tension (1)
- cytosolic water diffusion (1)
- date palm tree (1)
- design-by-analysis (1)
- ecological structure (1)
- epithelization (1)
- finite element analysis (1)
- flaw (1)
- fortschreitende plastische Deformation (1)
- gonarthrosis (1)
- hemoglobin (1)
- hemoglobin dynamics (1)
- human dermal fibroblasts (1)
- hydrogel (1)
- kontraktile Spannung (1)
- light scattering analysis (1)
- limit and shakedown analysis (1)
- linear kinematic hardening (1)
- load limit (1)
- material shakedown (1)
- metagenomics (1)
- microbial diversity (1)
- nonlinear kinematic hardening (1)
- pipes (1)
- plant stress (1)
- plasma generated ions (1)
- probabilistic fracture mechanics (1)
- protein (1)
- rhAPC (1)
- second-order reliability method (1)
- shotgun sequencing (1)
- subglacial aquatic ecosystems (1)
- subsurface ice (1)
- subsurface ice research (1)
- subsurface probe (1)
- tension–torsion loading (1)
- vessels (1)
- water bridge phenomenon (1)
- wound healing (1)
- yield stress (1)
Institute
- IfB - Institut für Bioengineering (63) (remove)
Originalausgabe: Orthopädische Praxis Jg. 47. 2011 H. 11; S. 536-543. Mit freundlicher Genehmigung des Verlags Zusammenfassung: Auf der Basis von Patientenabfragen mittels Fragebogen zum Schmerzempfinden und zur Einschränkung bei Aktivitäten des alltäglichen Lebens wird die Langzeitwirkung der MBST® KernspinResonanz-Therapie bei Gonarthrose untersucht. An der Studie nahmen 39 Patienten teil, bei denen die Therapie bis zu vier Jahre zurückliegt. Neben einer Gesamtbetrachtung wird der Erfolg auch in Abhängigkeit von Alter, Geschlecht und sportlicher Aktivität analysiert. Insgesamt weist die Studie auf eine anhaltende Verbesserung des Gesundheitszustands mit zum Teil deutlicher Schmerzlinderung auch noch nach vier Jahren hin, jedoch mit einer leichten Schmerzzunahme gegen Ende des Untersuchungszeitraums von vier Jahren. Eine tendenziell positivere Wirkung bei Frauen, älteren Menschen oder auch sportlich nicht-aktiven Patienten lässt auf eine mögliche Beeinflussung des Erfolgs der Therapie durch (Über-)Belastung im Alltag schließen. Ein zusätzlich positiver Effekt der Therapie auf die Knochendichte ist ebenfalls denkbar, dies bleibt jedoch offen.
In this work, the effects of carbon sources and culture media on the production and structural properties of bacterial cellulose (BC) synthesized by Medusomyces gisevii have been studied. The culture medium was composed of different initial concentrations of glucose or sucrose dissolved in 0.4% extract of plain green tea. Parameters of the culture media (titratable acidity, substrate conversion degree etc.) were monitored daily for 20 days of cultivation. The BC pellicles produced on different carbon sources were characterized in terms of biomass yield, crystallinity and morphology by field emission scanning electron microscopy (FE-SEM), atomic force microscopy and X-ray diffraction. Our results showed that Medusomyces gisevii had higher BC yields in media with sugar concentrations close to 10 g L−1 after a 18–20 days incubation period. Glucose in general lead to a higher BC yield (173 g L−1) compared to sucrose (163.5 g L−1). The BC crystallinity degree and surface roughness were higher in the samples synthetized from sucrose. Obtained FE-SEM micrographs show that the BC pellicles synthesized in the sucrose media contained densely packed tangles of cellulose fibrils whereas the BC produced in the glucose media displayed rather linear geometry of the BC fibrils without noticeable aggregates.
Tests with palm tree leaves have just started yet and scan data are in the process to be analyzed. The final goal of future project for palm tree gender and species recognition will be to develop optical scanning technology to be applied to date palm tree leaves for in–situ screening purposes. Depending on the software used and the particular requirements of the users the technology potentially shall be able to identify palm tree diseases, palm tree gender, and species of young date palm trees by scanning leaves.
Proceedings of the International Conference on Material Theory and Nonlinear Dynamics. MatDyn. Hanoi, Vietnam, Sept. 24-26, 2007, 8 p. In this paper, a method is introduced to determine the limit load of general shells using the finite element method. The method is based on an upper bound limit and shakedown analysis with elastic-perfectly plastic material model. A non-linear constrained optimisation problem is solved by using Newton’s method in conjunction with a penalty method and the Lagrangean dual method. Numerical investigation of a pipe bend subjected to bending moments proves the effectiveness of the algorithm.
Contractile behavior of the gastrocnemius medialis muscle during running in simulated hypogravity
(2021)
Vigorous exercise countermeasures in microgravity can largely attenuate muscular degeneration, albeit the extent of applied loading is key for the extent of muscle wasting. Running on the International Space Station is usually performed with maximum loads of 70% body weight (0.7 g). However, it has not been investigated how the reduced musculoskeletal loading affects muscle and series elastic element dynamics, and thereby force and power generation. Therefore, this study examined the effects of running on the vertical treadmill facility, a ground-based analog, at simulated 0.7 g on gastrocnemius medialis contractile behavior. The results reveal that fascicle−series elastic element behavior differs between simulated hypogravity and 1 g running. Whilst shorter peak series elastic element lengths at simulated 0.7 g appear to be the result of lower muscular and gravitational forces acting on it, increased fascicle lengths and decreased velocities could not be anticipated, but may inform the development of optimized running training in hypogravity. However, whether the alterations in contractile behavior precipitate musculoskeletal degeneration warrants further study.
Background
Hip fractures are a common and costly health problem, resulting in significant morbidity and mortality, as well as high costs for healthcare systems, especially for the elderly. Implementing surgical preventive strategies has the potential to improve the quality of life and reduce the burden on healthcare resources, particularly in the long term. However, there are currently limited guidelines for standardizing hip fracture prophylaxis practices.
Methods
This study used a cost-effectiveness analysis with a finite-state Markov model and cohort simulation to evaluate the primary and secondary surgical prevention of hip fractures in the elderly. Patients aged 60 to 90 years were simulated in two different models (A and B) to assess prevention at different levels. Model A assumed prophylaxis was performed during the fracture operation on the contralateral side, while Model B included individuals with high fracture risk factors. Costs were obtained from the Centers for Medicare & Medicaid Services, and transition probabilities and health state utilities were derived from available literature. The baseline assumption was a 10% reduction in fracture risk after prophylaxis. A sensitivity analysis was also conducted to assess the reliability and variability of the results.
Results
With a 10% fracture risk reduction, model A costs between $8,850 and $46,940 per quality-adjusted life-year ($/QALY). Additionally, it proved most cost-effective in the age range between 61 and 81 years. The sensitivity analysis established that a reduction of ≥ 2.8% is needed for prophylaxis to be definitely cost-effective. The cost-effectiveness at the secondary prevention level was most sensitive to the cost of the contralateral side’s prophylaxis, the patient’s age, and fracture treatment cost. For high-risk patients with no fracture history, the cost-effectiveness of a preventive strategy depends on their risk profile. In the baseline analysis, the incremental cost-effectiveness ratio at the primary prevention level varied between $11,000/QALY and $74,000/QALY, which is below the defined willingness to pay threshold.
Conclusion
Due to the high cost of hip fracture treatment and its increased morbidity, surgical prophylaxis strategies have demonstrated that they can significantly relieve the healthcare system. Various key assumptions facilitated the modeling, allowing for adequate room for uncertainty. Further research is needed to evaluate health-state-associated risks.
This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.
We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named “IceMole”, is currently developed, built, and tested at the FH Aachen University of Applied Sciences’ Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).
In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.