Filtern
Erscheinungsjahr
Dokumenttyp
Schlagworte
- Biomaterial (5)
- Bone (5)
- Biocompatibility (4)
- Ceramics (4)
- RFA (4)
- Röntgenfluoreszenzanalyse (4)
- Coating (3)
- Drawings (3)
- Recycling (3)
- Silberstiftzeichnung (3)
- Silverpoint drawing (3)
- Surface reaction (3)
- Synchrotron (3)
- X-ray spectrometry (3)
- XRF (3)
- XRF analysis (3)
- Albrecht Dürer (2)
- Archaeometry (2)
- Archäometrie (2)
- Beschichtung (2)
- Biomass (2)
- CdTe (2)
- Kinetics (2)
- Porosity (2)
- Pyrolysis (2)
- TGA (2)
- Zeichnungen (2)
- 3D printing (1)
- Additive Manufacturing (1)
- Alcium alkali phosphate (1)
- Bio active ceramic (1)
- Bioactive bone cement (1)
- Bioactive glass (1)
- Bioaktiv (1)
- Bioaktiver Knochenzement (1)
- Bioaktivität (1)
- Biodegradability (1)
- Biodegradation (1)
- Biokeramik (1)
- Biomaterial-bone-coating of an implant (1)
- Biomompatibilität (1)
- Bone defect (1)
- Bone substitute materials (1)
- Bone tissue engineering (1)
- CCQM (1)
- CIGS (1)
- CIS (1)
- Cadmium (1)
- Calcium alkali orthophosphate (1)
- Calcium alkali orthophosphates (1)
- Calcium alkaline orthophosphates (1)
- Calcium alkaline phosphates (1)
- Calcium phosphate (1)
- Calcium phosphate ceramics (1)
- Calcium-alkali-orthophosphate (1)
- Calcium-alkali-orthophosphate ceramics (1)
- Calciumalkaliorthophosphat (1)
- Calciumphosphat (1)
- Calciumtitanat (1)
- Catheters (1)
- Cell culture media (1)
- Central venous access port (1)
- Ceramic (1)
- Ceramic scaffolds (1)
- Chalcogenide photovoltaics (1)
- Char conversion (1)
- Char reactivity (1)
- Chromium (1)
- Coating(s) (1)
- Competencies (1)
- Complication (1)
- Curriculum (1)
- Denkmalpflege (1)
- Density (1)
- Dentin (1)
- EDX (1)
- Energy harvesting (1)
- Experimental study (1)
- Fetal bovine serum (1)
- Fitting (1)
- Gold (1)
- Histologie (1)
- Histology (1)
- Histomorphometrie (1)
- Histomorphometry (1)
- IFM (1)
- Implantatbeschichtung (1)
- In-vivo (1)
- Isoconversional (1)
- Kalzium Phosphat Zement, amorph. (1)
- Kalzium-Phosphat (1)
- Knochendefekt (1)
- Knochenersatz (1)
- Knochenkontakt (1)
- Lead (1)
- Leichtgranulat (1)
- Life cycle analysis (1)
- Mandible (1)
- Mass burning rate (1)
- Mass deposition (1)
- Mechanical processing (1)
- Mechanical testing (1)
- Mercury (1)
- Mineralization (1)
- Modeling (1)
- NDT-CE (1)
- Nuclear industry (1)
- Nuclear medicine (1)
- Oral surgery (1)
- Osteoblast differentiation (1)
- Osteoclast (1)
- Osteoclasts (1)
- Peptide synthesis (1)
- Photovoltaic (1)
- Plasmasprühen (1)
- Plastic (1)
- Polypropylene (1)
- Pool fire (1)
- Rapid prototyping (1)
- Reference material (1)
- Restauriermörtel (1)
- RoHS (1)
- Röntgenfluoreszenzanalyse (RFA) (1)
- STRATAGem (1)
- SaOS-2 cells (1)
- Scaffold (1)
- Schutzschicht (1)
- Silicone rubber (SiR) (1)
- Silver stylus (1)
- Simulated body fluid (1)
- Smouldering (1)
- Solubility (1)
- Stressed (1)
- Structure propertyrelationship (1)
- Surface Reaction (1)
- Surface analysis (1)
- TBPB (tert-butyl-peroxy benzoat) (1)
- Thermogravimetric analysis (1)
- Thermomagnetic generator (1)
- Thermoplastic polyurethane (TPU) (1)
- Thin film (1)
- Thin film modules (1)
- Three-dimensional (1)
- TiO2 (1)
- Titanträgermaterial (1)
- Toxicity (1)
- University (1)
- Unstressed (1)
- WEEE (1)
- Woody biomass (1)
- X-ray fluorescence (1)
- X-rays (1)
- Zement (1)
- crystal structures (1)
- gold (1)
- serine-protease inhibitor (1)
- Überzug (1)
Organisationseinheit der BAM
Data and prediction for the mass burning rate of a tert-butyl-peroxy-benzoat (TBPB) pool fire (pool diameter = 3 m) is presented. The mass burning rates of TBPB fires are up to six times higher and less dependent on pool diameter compared to hydrocarbon pool fires caused by an additional heat release rate due to exothermic decomposition reaction in the liquid phase. This heat release rate is calculated using a 1st order reaction kinetic obtained from micro calorimetric measurements. A new model is derived considering the heat release rate due to the decomposition reaction which is shown to be 100 % of the heat release rate radiated to the pool surface. With the presented model, including also physical quantities, especially the limiting fuel concentration for upward flame propagation, it is possible to predict the mass burning rates of large TBPB pool fires. The predicted values are in very good agreement with the experiments.
A kinetic model of smouldering of pine wood is determined by thermo-gravimetric analysis (TGA), describing the reactions of wood pyrolysis, wood oxidation and char oxidation. Thermo-gravimetric experiments were conducted with constant heating rates ranging from 2.5 to 10 K/min in atmospheres of pure nitrogen and mixtures of nitrogen and oxygen (with 20.5%, 8.2% and 4.3% O2). At first wood pyrolysis and char oxidation experiments are carried out in an independent way. Then smouldering experiments are conducted, which combine the two previous reactions with wood oxidation. Finally, the heats of the reactions are determined by differential scanning calorimetry (DSC). The results are discussed, compared with the literature and the derived kinetic model is presented, which includes five components: three pseudo-components of wood – representing roughly cellulose, hemi-cellulose and lignin – as well as char and ashes.
Calcium alkaline phosphate scaffolds for bone regeneration 3D-fabricated by additive manufacturing
(2012)
Calcium alkaline phosphate granulates can be used for substitution of several bone defects but for the reconstruction of large skeletal parts in the maxillofacial and orthopaedic fields fitted scaffolds are preferable. Within the additive manufacturing methods, the 3D printing process offers exciting opportunities to generate defined porous scaffolds. We used a R1 printer from ProMetal Company, USA, for producing scaffolds directly from a ceramic powder. For this direct free form fabrication technology the powder has to possess a lot of specific properties both for the generation of a stable green body and also for the subsequent sintering preparation. For this printing process we prepared different granules in a fluidized bed process containing Ca2KNa(PO4)2 as main crystalline phase. Granules were characterized by different methods and several sieve fractions were used for preparing disc like and cylindrical parts. The suitability of granules for this printing process was determined by porosity and strength of produced bodies. Next to granules' performance both of these properties can be directly influenced by 3D printing process parameters. With knowledge of suitable process parameters scaffolds with different porosity in a respective desired design can be created. In this study, cylindrical scaffolds with graded porosity were produced for bone regeneration of segmental defects in maxillofacial surgery and dental implantology by tissue engineering.
Ideally, bioactive ceramics for use in alveolar ridge augmentation should possess the ability to activate bone formation and, thus, cause the differentiation of osteoprogenitor cells into osteoblasts at their surfaces. Therefore, in order to evaluate the osteogenic potential of novel bone substitute materials, it is important to examine their effect on osteoblastic differentiation. This study examines the effect of rapidly resorbable calcium-alkali-orthophosphates on osteoblastic phenotype expression and compares this behavior to that of β-tricalcium phosphate (TCP) and bioactive glass 45S5. Test materials were three materials (denominated GB14, GB9, GB9/25) with a crystalline phase Ca2KNa(PO4)2 and with a small amorphous portion containing either magnesium potassium phosphate (GB14) or silica phosphate (GB9 and GB9/25, which also contains Ca2P2O7); and a material with a novel crystalline phase Ca10[K/Na](PO4)7 (material denominated 352i). SaOS-2 human bone cells were grown on the substrata for 3, 7, 14, and 21 days, counted, and probed for an array of osteogenic markers. GB9 had the greatest stimulatory effect on osteoblastic proliferation and differentiation, suggesting that this material possesses the highest potency to enhance osteogenesis. GB14 and 352i supported osteoblast differentiation to the same or a higher degree than TCP, whereas, similar to bioactive glass 45S5, GB9/25 displayed a greater stimulatory effect on osteoblastic phenotype expression, indicating that GB9/25 is also an excellent material for promoting osteogenesis.
Bioactive ceramics used as coating materials combine the conductive properties of a bioceramic with the mechanical stability of the metal implant. We studied a calcium zirconium phosphate-containing coating material, FA-CZP [Ca5(PO4)3F, CaZr4(PO4)6], that is relatively insoluble in the biological milieu. The reaction of bone to this material was investigated histologically and histomorphometrically in an animal trial. Cylindrical Ti6Al4V specimens that had been coated with FA-CZP by plasma spraying were implanted in the femoral condyles of rabbits. The implants were left in place for 2, 4, 6, 12, and 14 weeks. FA-CZP led to impaired mineralization of the newly formed bone at the interface. Noncalcified osteoid was found throughout the whole study period. The layer seemed to become thicker with time. The mineralization disorder is evidently caused by zirconium ions. The presence of zirconium in the osteoid in contact with the implant was demonstrated by means of two different staining methods.
A sustainable recycling of photovoltaic (PV) thin film modules gains in importance due to the considerable growing of the PV market and the increasing scarcity of the resources for semiconductor materials. The paper presents the development of two strategies for thin film PV recycling based on (wet) mechanical processing for broken modules, and combined thermal and mechanical methods for end-of-life modules. The feasibility of the processing steps was demonstrated in laboratory scale as well as in semi-technical scale using the example of CdTe and CIS modules. Pre-concentrated valuables In and Te from wet mechanical processing can be purified to the appropriate grade for the production of new modules.
An advantage of the wet mechanical processing in comparison to the conventional procedure might be the usage of no or a small amount of chemicals during the several steps.
Some measures are necessary in order to increase the efficiency of the wet mechanical processing regarding the improvement of the valuable yield and the related enrichment of the semiconductor material.
The investigation of the environmental impacts of both recycling strategies indicates that the strategy, which includes wet mechanical separation, has clear advantages in comparison to the thermal treatment or disposal on landfills.