Polymer derived ceramic materials from Si,B and MoSiB filler-loaded perhydropolysilazane precursor for oxidation protection

Silica-based coating systems were developed using polymer derived ceramics (PDCs) technology. Ceramic composites on the base of a SiO₂ and SiNO matrix and homogeneously distributed Mo₅SiB₂, SiB₆, Si and B fillers were manufactured. The coating systems have low porosity and provide a high oxidation resistance up to 100 h at 800 °C and 1100 °C in air. The influence of temperature and atmosphere of pyrolysis on the polymer precursor, the volume fraction of filler materials on the chemical composition of compacts as well as their high-temperature oxidation protection was investigated.     

TCMI: a non-parametric mutual-dependence estimator for multivariate continuous distributions

Data Mining and Knowledge Discovery - The identification of relevant features, i.e., the driving variables that determine a process or the properties of a system, is an essential part of the...     

Self-assembled microstructured polymeric and ceramic surfaces

Self-assembled microstructures were manufactured by dip coating of substrates with unfilled and filler-loaded preceramic polymer mixtures in the presence of a solvent and a non-solvent. The nature of the polymers was characterized by their solubility parameters. Variation of the polymer/polymer ratio and the volume fraction of the solvent and/or non-solvent led to different surface structures. Studies of the structure formation mechanism indicate that demixing processes of the polymers are responsible for self-assembly in filler-free mixtures. In filler-loaded mixtures the structure formation process, however, is more complex. The micro-structured polymeric coatings obtained from filler loaded systems were converted into polymer derived ceramic coatings under shape retention. High specific surface areas were measured after thermal conversion.     

Application of instantaneous profile measurement of moisture content and moisture potential in porous materials

Due to limits in current moisture content and moisture potential measurement technology, moisture transport is normally investigated under equilibrium conditions. Most processes we observe in nature are, however, transient and hardly ever reach an equilibrium stage. This means that future experimental methods in moisture transport investigation will focus on transient processes. One such method is the instantaneous profile measurement (IPM) technique frequently used in soil science. It can be applied to investigate moisture transport under transient conditions. Two measurement principles are combined in one material to record data for moisture content and moisture potential at the same time and at various points. As output, moisture content and moisture potential profiles are plotted against space and time. The method was applied to different porous materials, and hygroscopic loading and deloading cycles were conducted in the relative humidity range between 30 and 97%. The data obtained is not in strict agreement with static or steady-state observations. This reveals information about moisture transport kinetics. These findings are discussed in the context of the literature and with regard to their significance for current moisture transport models, which are typically based on equilibrium data.     

High glycolytic potential does not predict low ultimate pH in pork

Extent of postmortem pH decline influences meat quality development. To better understand physiological determination of ultimate pH (pH_u), we utilized female and castrated male pigs from a line whose selection index includes differentiated pH_u. All genotypes of AMP-activated protein kinase γ3 subunit (AMPKγ3) V199I site were present. The mutant 199II genotype increased pH_u, but only in castrated males. Genotype affected glycolytic potential (GP), but GP was weakly associated with pH_u. A subset of animals was selected based on low (− Gly) and high (+ Gly) residual glycogen content, and compared with AMPKγ3 200Q, which is associated with low pH_u. Both + Gly and 200Q muscle contained glycolytic substrate at 24 h; however, 200Q muscle generated low pH_u and greater lactate compared to + Gly. Additionally,− Gly and + Gly groups exhibited similar pH_u despite a large difference in GP. In conclusion, high GP does not appear to directly impact the extent of postmortem pH decline.     

Limitations of rapid myelin water quantification using 3D bSSFP

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Imaging of the myelin water fraction (MWF) is conventionally performed using a multi-echo spin-echo sequence. This technique requires long acquisition times and therefore often suffers from a lack of volume coverage. In this work, the application of 3D balanced steady-state free precession (bSSFP) sequences to extract high-resolution myelin water maps is discussed.     

Bindemittelfreie zeolithische Molekularsiebe der Typen LTA und FAU

Zeolite molecular sieves belong to the most important adsorbents. For dynamic, technical adsorption processes the use of shaped bodies is required. In conventional molecular sieves usually clay type minerals are used as binder. In this paper novel binderless zeolite molecular sieves and their advantages in comparison to binder containing molecular sieves are shown.