Improved scratch resistance for antireflective coatings on sapphire

Antireflective coatings on sapphire were optimized by variation of the coating design, the total thickness, and the highly refractive material used. The coatings were characterized with a focus on their scratch resistance. An increased resistance against scratching wear is shown for hafnia-containing coatings with a total thickness of about 500?nm.     

Influence of austenite strength on martensite start temperature Ms

It is known that austenite strength determines the morphology of the new phase during martensitic transformation. As the strength of austenite influences the growth of a martensite crystal, i.e. the movement of the austenite/martensite interface, a correlation between strength of the parent phase and M_s has to exist. M_s depends on thermodynamical and mechanical properties of the alloys. To distinguish the individual variables, austenite strength was changed by different hardening mechanisms: solid solution hardening, plastic deformation or both.     

Occurrence of a nitro metabolite of a defined nonylphenol isomer in soil/sewage sludge mixtures

Uniformly [14C]-ring-labeled 4-(3,5-dimethyl-3-heptyl)phenol (353-nonylphenol) is a highly relevant isomer of the technical nonylphenol mixture. We studied the sorption, desorption, and degradation of the synthesized isomer in an agricultural sandy loam at various soil/sewage sludge ratios. Sorption of 353-nonylphenol was high and differed with the amount of suspended soil in water. log Koc values, which are used to assess the risk of nonylphenol, ranged from 3.80 to 5.75. Desorption was slow and low and resulted in constant concentrations of about 15 ng/L353-nonylphenol in water after several desorption steps. In degradation studies up to 6% of the applied 353-nonylphenol in soil was volatilized; we consider this an important source of nonylphenol in the environment. With increasing amounts of sewage sludge in the soil/sewage sludge mixtures, 353-nonylphenol was stabilized, probably because of the lack of oxygen in sludge aggregates even under oxic conditions in flow-through systems. Unexpectedly, a less-polar metabolite was detected in amounts up to 40% of the applied nonylphenol after 135 days of incubation. This novel metabolite was identified as 4-(3,5-dimethyl-3-heptyl)-2-nitrophenol. This product formation might indicate the existence of novel metabolic pathways of nonylphenol in the environment.     

The nuclear actin-related protein Act3p/Arp4p is involved in the dynamics of chromatin-modulating complexes

Chromatin remodelling and histone-modifying complexes govern the modulation of chromatin structure. While components of these complexes are diverse, nuclear actin-related proteins (Arps) have been repeatedly found in these complexes from yeast to mammals. In most cases, Arps are required for functioning of the complexes, but the molecular mechanisms of nuclear Arps have as yet been largely unknown. The Arps and actin, sharing a common ancestor, are supposed to be highly similar in the three-dimensional structure of their core regions, including the ATP-binding pocket. The Arp Act3p/Arp4p of Saccharomyces cerevisiae exists within the nucleus, partly as a component of several high molecular mass complexes, including the NuA4 histone acetyltransferase (HAT) complex, and partly as uncomplexed molecules. We observed that mutations in the putative ATP-binding pocket of Act3p/Arp4p increased its concentration in the high molecular mass complexes and, conversely, that an excess of ATP or ATPgammaS led to the release of wild-type Act3p/Arp4p from the complexes. These results suggest a requirement of ATP binding by Act3p/Arp4p for its dissociation from the complexes. In accordance, a mutation in the putative ATP binding site of Act3p/Arp4p inhibited the conversion of the NuA4 complex into the smaller piccoloNuA4, which does not contain Act3p/Arp4p and exhibits HAT activity distinct from that of NuA4. Although the in vitro binding activity of ATP by recombinant Act3p/Arp4p was found to be rather weak, our observations, taken together, suggest that the ATP-binding pocket of Act3p/Arp4p is involved in the function of chromatin modulating complexes by regulating their dynamics.     

Polysaccharidzus?tze in eiwei?reichen Lebensmitteln

Zusammenfassung Aus der Literatur bekannte Verfahren zur Isolierung von Polysacchariden aus eiweißreichen Lebensmitteln, insbesondere Frischkäsen, erwiesen sich im praktisch interessanten Bereich (0,01–0,2% Bindemittelzusatz) als wenig brauchbar. Stattdessen wird folgende Probenaufbereitung vorgeschlagen: 1. Entfettung der Proben mit einem Gemisch von Äthanol, Diäthyläther und Petroläther; 2. vollständige Hydrolyse der Proteine mit Pepsin, Pronase E und einem Gemisch von Aminopeptidase M und Prolidase; 3. Abtrennung der Polysaccharide von den niedermolekularen Substanzen und von Enzymresten durch Gelfiltration an Biogel P-2; 4. Konzentrierung der polysaccharidhaltigen Fraktion durch Gefriertrocknung, Ultrafiltration oder Eindampfen.- Das Verfahren wurde am Beispiel von Speisequark und Doppelrahmfrischkäse erprobt, ist im Prinzip aber verallgemeinerungsfähig.

---

Polysaccharide additives in foods rich in proteinsI. Sample preparation for estimation, especially in fresh cheese

Summary Published procedures for the isolation of polysaccharides from foods rich in proteins, especially fresh cheese, proved not very useful for the concentration in question (0,01–0.2%). We, instead, propose the following sample preparation: 1. Removal of lipids by an ethanol - ethyl ether - petrol ether mixture; 2. complete hydrolysis of proteins with pepsin, pronase E and a mixture of Amnopeptidase M and prolidase; 3. separation of the polysaccharides from the low molecular substances and from enzyme residues by gel filtration on Biogel P-2; 4. concentration of the polysaccharides containing fraction by freeze drying, ultrafiltration or evaporation. - The method was tested with quarg and double cream fresh cheese, it can, however, be adopted to use in other products.

---

---

Deutsches Wollforschungsinstitut, Aachen.     

Chemical technology of natural gas – its present state and prospects

Against the background of long-term availability of natural gas, its present technology and future prospects are described. Particular emphasis is put on the oxidative coupling of methane to C₂₊ hydrocarbons: (1) Catalyst development, activity, selectivity and deactivation as well as reactor operation are discussed; (2) a tentative process scheme is put forward and its economics evaluated with respect to ethylene production.     

Anforderungen an Stahl‐ und Verbundknoten bei Stützenausfall in einem Rahmentragwerk

Eine lokale Schädigung innerhalb der Tragstruktur (z. B. Stützenausfall durch Anprall oder Explosion) kann zu einem Versagen der Gesamtstruktur und damit zum Einsturz des Gebäudes führen. Um solch ein globales Versagen durch lokale Schädigung zu vermeiden, muss innerhalb der Tragstruktur eine Umlagerung der Schnittgrößen ermöglicht werden, d. h., es müssen sich alternative Lastpfade ausbilden können. Solch eine Umlagerung, z. B. von einem reinen Biegezustand in einen gemischten Biege‐/Membranspannungszustand, bedingt unter Umständen sehr große Verformungen, die zu großen Deformationen der Anschlüsse führen. Im Rahmen eines europäischen RFCS‐Forschungsprojektes wurde versucht, mit Hilfe sehr duktiler Anschlussausbildungen die Robustheit von Stahl‐ und Verbundrahmentragwerken zu verbessern. Hauptaugenmerk bei der Konzeption der Anschlüsse war dabei, den Material‐ und Fertigungsaufwand der Anschlüsse so gering wie möglich zu halten und die Umlagerungsmöglichkeiten für außergewöhnliche Bemessungssituationen vornehmlich über das Vorhalten hoher Verformungskapazitäten der Anschlüsse zu aktivieren. Aus diesem Grund wurden hier nachgiebige teiltragfähige Anschlüsse gewählt. Als außergewöhnliche Bemessungssituation wurde in diesem Projekt schwerpunktmäßig der Stützenausfall in einem Rahmentragwerk betrachtet. (RFCS Research Fund for Coal and Steel) Requirements on steel‐ and composite joints for the load case column removal. Local failure in a structure (e. g. sudden column loss due to impact or explosion) may lead to progressive collapse propagation of the global structural system resulting in a total collapse. To avoid progressive collapse initiated by local damage a redistribution of force from the damaged part of the structure has to be enabled by alternate load paths. Activation of alternate load paths by change of the bearing mechanism from pure bending state to more or less pure membrane state is a measure that is only possible by allowing large deformations resulting in high deformation requirements for the joints. In the course of an European RFCS research project ductile joint solutions have been developed to improve the robustness as characteristic of the structure. Main focus of the joint design was to obtain the required deformation capacity for accidental design situations mainly from ductile joint and cause at the same time only few additional material and fabrication costs for the joints. As a result semi‐rigid and partial‐strength joint solutions have been chosen. Objectives within the project were to determine requirements of the joints concerning deformation capacity as well as M‐N‐resistance to enable the activation of catenary action for the load case notional column removal.     

Emulsifier Composition of Solid Lipid Nanoparticles (SLN) Affects Mechanical and Barrier Properties of SLN‐Protein Composite Films

Protein films can be applied to improve food quality and to reduce packaging waste. To overcome their poor water barrier properties, lipids are often incorporated. The function of incorporated lipid depends on the interface between filler and matrix. This study aimed to tailor the properties of a protein–lipid film by designing the oil/water interface to see if the concept of inactive/active filler is valid. Therefore, we varied the emulsifier stabilizing solid lipid nanoparticles (SLN) to promote (via β‐lactoglobulin) or to minimize (via Tween 20) interactions between particle surface and protein. SLN were incorporated into protein films and film properties were determined. Addition of SLN led to significantly decreased water vapor permeability (WVP) of protein films. However, WVP was mainly affected by the emulsifiers and not by the lipid. Protein‐stabilized SLN (BS) replaced a lacking protein in the protein network and therefore did not influence the mechanical properties of the films at ambient temperature. BS‐composite films were temperature sensitive, as lipid and sucrose palmitate melted at temperatures above 40 °C. Tween 20‐stabilized SLN (TS) led to reduced tensile strengths, probably due to perturbative effects of TS and plasticizing effects of Tween 20. Dynamic mechanical analysis showed that TS and Tween 20 increased film mobility. Melting of lipid and emulsifiers, and temperature‐dependent behavior of Tween 20 led to a strong temperature dependence of the film stiffness. By designing the interface, particles can be used to tailor mechanical properties of protein films. Tuned edible films could be used to control mass transfers between foods.