Synthesis, characterization and reaction behaviour of lamellar AFm phases with aliphatic sulfonate-anions

The addition of alkanesulfonates as admixtures to cementitious materials allows the formation of new lamellar phases (AFm), which was proofed by X-ray diffraction (XRD). The course of hydration was investigated by heat flow calorimetry.The layered structures of AFm phases are composed of brucite-like main layers and interlayers containing alkanesulfonate ions and additional H₂O molecules. These structural not necessary H₂O molecules release gradually at definite steps with increasing temperature. With varying relative humidity the layer thickness c′ of short aliphatic chained calcium aluminate alkanesulfonate hydrates changes considerably, whereas large organic molecules dominate the layer thickness of those with longer aliphatic chains. By means of the increase of layer thickness with increasing chain lengths it is possible to determine the tilt angles of the aliphatic chains in the interlayers.     

Effect of pH on Sedimentation of Cod (Gadus morhua) Muscle Membranes

ABSTRACT: A new process solubilizes muscle proteins, making it possible to separate membranes with their oxidizable phospholipids, but it requires a high centrifugal force to separate the membranes. In this study we show that isolated cod muscle membranes could be readily sedimented at a low centrifugal g force for 15 min at pH 5 or below but not at pH 6 or higher. Isoelectric aggregation is likely to be responsible for the sedimentation of isolated membranes at these low pH values. Various consecutive pH treatments on isolated membranes showed that certain proteins were resolubilized or resuspended at a final pH of 10.5 if they had been previously exposed to pH 3,4, or 5. pH adjustment to 10.5 before adjustment to a pH of 5 or lower inhibited the sedimentation of isolated membranes. Isolated membranes added to the supernatant of homogenized muscle solubilized at pH 3 and centrifuged at 10000 × gfor 30 min also sedimented at 4000 × gfor 15 min. This was in contrast to the membranes naturally present in the solubilized homogenate. This suggests that factors other than viscosity were involved in the lack of efficient sedimentation of membranes from solubilized muscle tissue.     

Future Net: Spekulationen über das Internet der Zukunft

Das Internet wird traditionell als eine Kommunikationsinfrastruktur betrachtet. Mit ihr ist es möglich—so der Anspruch—jede Information zu jedem Zeitpunkt an jeden Ort zu transportieren.     

Depth-Resolved Porosity Investigation of EB-PVD Thermal Barrier Coatings Using High-Energy X-rays

Demands for designing prime reliant, energy-efficient, and high-performance thermal barrier coatings (TBCs) in gas turbines have led to a growing interest toward comprehensive microstructural characterization. Here we investigate the novel use of high-energy X-rays for small-angle X-ray scattering (SAXS), together with wide-angle scattering and radiography, for the depth-resolved characterization of TBCs grown by electron beam physical vapor deposition (EB-PVD). The coating microstructure is found to consist of columns perpendicular to the substrate, extending through the thickness, with a [001] growth texture and significant intercolumnar porosity. In addition, overshadowing effects during deposition together with gas entrapment give rise to nanoscale intracolumnar porosity consisting of featherlike and globular pores. Radiography showed an increase in the total porosity, from 15% near the substrate to 25% near the coating surface, which is ascribed to an increase in the intercolumnar spacing at the top of the coating. By contrast, the small-angle scattering studies, which are sensitive to fine features, showed the pore internal surface area to be greatest near the substrate.     

Bayesian eggs and Bayesian omelettes: Reply to Stern (2005).

In this response to Stern's (2005) (see reocord 2005-16136-010) discussion of Klugkist, Laudy, and Hoijtink (2005), model inference based on posterior probabilities on the parameter space is discussed. Furthermore, the authors respond to Stern's example in which all possible orderings are included via a short discussion of exploratory versus theory-based modeling. Finally, the authors show that the Bayesian approach is flexible and can deal with many types of constraints. This is illustrated using a model with constraints on the differences between means. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cooling of arc furnace electrodes with heat pipes

Combination electrodes with water cooling shanks, which have been introduced to reduce graphite consumption in UHP furnaces, cause the danger of vapour explosions in case of breakIng. Heat pipes are highly efficient two phase heat conductors which could provide a safer alternative to water cooling shanks, since they contain only a small amount of liquid. The transport of energy results from evaporation of the working fluid in the heated section, convection of the vapour to the cooled section and reflux of the condensed fluid to the heated end. Large heat quantities can be transferred under nearly isothermal conditions within the tube, as long as certain limits are not exceeded. The operating temperature can be controlled by design parameters such as the thermal resistance of the cooling zone. The proper function of heat pipes for cooling arc furnace electrodes is investigated by comparing the calculated heat load with temperature dependent limits to heat transport. It is shown that copper tubes with water as the working fluid combine efficient cooling and safe performance in the low temperature range, while the cheaper steel tubes with sodium filling are suitable for high temperature operation.     

3D deep X-ray lithography for producing a multi-channel Fourier transform interferometer

We introduce a modified LIGA process architecture to manufacture a static lamellar grating Fourier-transform spectrometer invented by Moser and Möller (European patent EP 0 765 488 B1, 1994). Such spectrometers hold unique advantages over common Michelson-type FTIRs including high time resolution, speed, compactness, and robustness. To cope with the spectrometer’s demand for precise high-aspect-ratio micro-fabrication, we present a modified LIGA process which enhances the X-ray lithography by means of a moving mask technique (Heussler and Moser Lithography method and apparatus PCT/SG2011/000376, 2011). The technique relies on independently moving multiple masks stacked on top of each other during the lithographic step and thus allows to locally vary the deposited dose in a positive tone photoresist. First manufacturing results as well as a performance test of a prototype spectrometer are reported.     

Struktur und eigenschaften von ABS-polymeren. IX. Quantitative untersuchungen zur morphologie von ABS-polymerisaten

The technological properties of ABS polymers largely depend on the structure of the elastomer phase as well as on the elastomer/thermoplast interface. The morphological structure of such polymers can be determined from electron micrographs of ultramicrotome sections – after selective contrasting of the polybutadiene phase – or of replicas of fracture surfaces after selective chemical degradation. The various ABS polymers are classified by their manufacturing processes and their morphologies and characterized by electron micrographs. The degree and place of grafting are of particular importance. The quantitative determination of the surface- and internal grafting is achieved by combining the determination of the degree of grafting (extraction), the evaluation of the results obtained on particle counting, and a morphometric process. It is demonstrated that the morphometric process can in general be applied for the quantitative determination of the contrastable component in two-phase polymers.