Einfluß des Mangangehaltes auf die Abschreck- und Reckalterung von Kohlenstoff und/oder Stickstoff

Ermittlung der Ausscheidungskinetik verschiedener Eisen-Kohlenstoff-, Eisen-Stickstoff- und Eisen-Kohlenstoff-Stickstoff-Legierungen mit und ohne Mangan durch Aufnahme von Dämpfungskurven nach unterschiedlich langer Auslagerung. Aufnahme von Spannung-Dehnung-Kurven nach Abschreck- und Reckalterung und Vergleich des zeitlichen Verlaufs mit dem der Ausscheidungen.     

Einflu? verschiedener Schmelzsalze auf die Qualit?t und Haltbarkeit von Schmelzk?se

Zusammenfassung Der Einflu? von Schmelzsalzen auf die Qualit?t und Haltbarkeit von Schmelzk?se wurde in einem Versuch mit 4 K?sesorten und 10 Schmelzsalzen in 18w?chiger Lagerung bei 4 verschiedenen Temperaturen untersucht. Dabei zeigte sich, da? die günstigen Eigenschaften der Polyphosphate durch die anderen geprüften Schmelzsalze nicht zu erreichen sind: Orthophosphate ergeben K?se, die organoleptisch unbefriedigend sind. ?hnliches, wenn auch in geringerem Ma?e, gilt für Pyrophosphate.' Citrate, die sich zum Schmelzen von Blockk?se — abgesehen von evtl. auftretender Marmorierung — eignen, neigen relativ leicht zu bakteriellem Verderb (Trieb) und sind in dieser Hinsicht den Polyphosphaten unterlegen. Die ausgezeichneten Eigenschaften der Polyphosphate als Schmelzsalze beruhen auf hervorragendem Calciumbindungsverm?gen bei hinreichender Pufferkapazit?t. Aufgabe der Schmelzsalze ist, das schwer l?sliche Ca-Paracaseinat in das leichter l?sliche Na-Paracaseinat zu überführen und durch Einhaltung eines gewissen pH-Wertes das Verhalten des Proteins zu fixieren. Dabei wirken die Polyphosphate als Ionenaustauscher. Diese Anschauungen konnten durch Bestimmung des Ca-Bindungsverm?gens von Polyphosphaten bei verschiedenen pH-Werten als auch durch Schmelzversuche mit dem Ca-Komplexbildner EDTA gestützt werden. Die Schmelzversuche wurden von HerrnLeicht, Neu-Ulm, ausgeführt, dem hier für seine wertvolle Hilfe gedankt sei. Für die sorgsame Ausführung der Untersuchungen danken wir unseren Mitarbeiterinnen Frl.E. Glindemann, Frl.I. Seitz, Frl.L. Liebherr, Frl.U. Dahncke, Frl.B. Hilme, FrauG. Koppert, Frl.G. Schenk, FrauR. Linders, Frl.Ch. Meyer, FrauW. Rickert, FrauE. Fischer. Herrn Prof. Dr. Dr.W. Diemair zum 65. Geburtstag gewidmet.     

Low‐alloyed TRIP‐Steels with Optimized Strength,Forming and Welding Properties

To obtain the superior strength‐ductility‐balance of TRIP‐grades, a special chemical composition in combination with well adapted processing parameters are a prerequisite. Despite of their excellent formability performance in terms of drawability as characterized by high n‐ and elongation values, compared to mild steels TRIP‐grades are challenging in the press and the body shops. The high strength level in combination with the high work hardening of TRIP‐grades result in higher levels of spring back compared to mild steels and higher press forces are required. Furthermore, a higher sensitivity to failure for sharp bending radii and a deterioration of the formability of punched edges is reported for TRIP‐grades. While spring back can only be minimized by advanced forming processes supported by new simulation techniques with improved ability to predict spring back, the sensitivity to failure under special forming conditions can be influenced by optimizing microstructural features. Contrary to the forming behaviour, which is influenced significantly by the microstructure, the weldability is mainly governed by the chemical composition and the surface condition of the material. The high carbon content of TRIP‐grades compared to mild steels results in a higher hardening potential after welding. Additionally, a fracture behaviour untypical for mild steels after destructive testing of spot welds is sometimes observed for TRIP‐grades, which is assessed critically by some OEMs. In this work, after a discussion of the processing conditions, possibilities are demonstrated to improve the forming behaviour by an optimization of the microstructure and the spot weldability by adapting the chemical composition of low‐alloyed TRIP grades. First very promising results for TRIP‐grades with a minimum tensile strength level of 700 MPa are discussed.     

The neglect of aesthetics in landscape planning in Switzerland

In this paper, landscape is defined as any part of the Earth’s surface in which various aspects, such as terrestrial, aquatic, natural and cultural interact with differing dominance. Within landscapes, energy and material flows over time are major driving forces of landscape dynamics. Such a comprehensive approach to landscape should also be applied in landscape planning, however this is rarely the case in Switzerland. The concept of landscape aesthetics in particular is neglected, therefore, four theses are formulated and discussed in this paper.The tourist industry promotes Switzerland with pictures showing beautiful scenery. Some of the landscape elements shown, e.g. ecclesiastical buildings and historical profane buildings, are widely recognised for their aesthetic values, and scientifically examined by art historians and other disciplines. Strangely enough, this is not the case for cultural landscapes, despite the fact that they also reflect the history of human culture. This paradox evolves from the dichotomy between natural sciences and humanities. There is a lack of multi-, inter-, and trans-disciplinary approaches to studying cultural landscapes. The long-term genesis of the elements of the cultural landscape is illustrated by the typical structure of traditional cultural landscapes, i.e. “the hides of land” (i.e. strip-shaped forest clearings) (Hufenfluren).Between 1750 and 1850, many painters depicted the beauty of the traditional cultural landscape. Their paintings are acknowledged as a part of culture and treated accordingly, but this is not the case for the remains of the cultural landscape they painted. Comparing maps from different points in time reveal the loss of elements of cultural landscapes. Results show how traditional systems of land use led to highly structured landscapes, whereas today’s land-use levels out the scenery. Lack of public support significantly reduces the success of the legal tools to limit this process.     

GSSTP: a signalling transport protocol for DVB‐S2 GSE‐only transmission systems

The current signalling framework for Digital Video Broadcasting systems is based on MPEG‐2 encoded Program Specific Information and System Information tables that rely on the transport stream. It is expected that in the near future, this architecture will be replaced by one based on the Generic Stream Encapsulation protocol, paving the way for the convergence of DVB‐S2 broadcast transmission networks and IP infrastructure. This paper presents a new lightweight Generic Stream Signalling Transport Protocol, which can be used to realise a transmission system based only on the Generic Stream Encapsulation and that efficiently supports filtering of Program Specific Information and System Information tables. Copyright © 2012 John Wiley & Sons, Ltd.     

A Rapid Screening Method for the Tremorgenic Indole-Diterpene Alkaloid Mycotoxin Paxilline in Beer

The tremorgenic paxilline (PAX), an indole-diterpene alkaloid mycotoxin, was recently detected as a natural contaminant of ergot of barley and rye. To check the possibility of a transfer of this mycotoxin into beer, a rapid and sensitive immunochemical method for the analysis of PAX in commercial bottled beer was developed. A straightforward sample preparation procedure could be established, including degassing, pH adjustment, optional filtering, and finally a 1:5 dilution with a methanolic phosphate-buffered saline solution. Analysis of PAX was performed by a competitive indirect enzyme immunoassay (EIA). The detection limit at a cut-off value of 80% B/B₀ of the EIA standard curve was evaluated by analysis of spiked beer. PAX at levels of 3 μg/L and 5 μg/L yielded 69% and 100% positive results, therefore the detection limit in beer was at 5 μg/L. Recoveries of PAX at levels of 5–20 μg/L were 88–97%, coefficients of variation were 17–22%. With these characteristics, the EIA was considered to be a suitable screening method for PAX in beer. A survey of bottled beer from the German market was conducted which included 38 samples of domestic and international brands, the latter containing various flavoring ingredients. All samples were clearly negative for PAX, which indicates that this toxin is not a relevant contaminant in beer.     

Flow front advancement during composite processing: predictions from numerical filling simulation tools in comparison with real‐world experiments

Liquid composite molding (LCM) techniques are innovative manufacturing processes for processing fiber reinforced polymer parts used e.g. for aerospace structures. Thereby the reinforcing material is placed in a mold and infiltrated with a low viscosity polymer matrix. Increasing production rates as well as part complexity lead to high production risks such as air inclusions or incomplete mold filling. Numerical mold filling simulations are promising tools enabling the composite manufacturing engineer to detect dry spots in the mold and find the optimal positions of the resin entry and ventilation system at an early process development stage. Today, different numerical models and software packages are available for modeling the flow through the reinforcing structure for visualization of the flow behavior. The goal of this study is the systematic comparison of two different software packages, namely PAM‐RTM^® and OpenFOAM. Both software tools are operated as they are commonly foreseen. Real world experiments under real process conditions are the basis for the assessment of the numerical predictions. The resin transfer molding (RTM) experiments are executed in a tool with a transparent upper mold half in order to see the flow front advancement. POLYM. COMPOS., 37:2782–2793, 2016. © 2015 Society of Plastics Engineers     

Ultrasound velocity and attenuation of porcine soft tissues with respect to structure and composition: I. Muscle

Ultrasound velocity and attenuation of soft tissues have been widely investigated. However, few studies completely covered considerable variations of both, structure and composition. The aim of this study was to collect acoustic reference data of porcine Longissimus muscle and associate them with compositional traits. In addition, measurements were conducted on fresh, formalin fixed, and frozen-thawed samples to evaluate the effect of processing on ultrasound parameters and comparisons with earlier investigations. Measurement conditions (temperature and fibre orientation) were realised close to hanging carcasses conditions. Sound velocity ranged from 1617 ± 6 to 1622 ± 5 ms(-1), while attenuation mostly ranged from 1.0 ± 0.3 to 1.2 ± 0.3 dB MHz(-1)cm(-1). Only formalin fixed samples showed significantly higher attenuation (2.2 ± 0.6 dB MHz(-1)cm(-1)). Highest correlations have been observed between intramuscular fat and attenuation (up to r = .7). The obtained results are anticipated to improve ultrasound based estimation of the intramuscular fat of pig muscle on intact carcasses.     

Hard implant coatings with antimicrobial properties

Infection of orthopaedic implants often leads to inflammation immediately after surgery and increases patient morbidity due to repetitive operations. Silver ions have been shown to combine good biocompatibility with a low risk of inducing bacterial resistance. In this study a physical vapour deposition system using both arc deposition and magnetron sputtering has been utilized to produce silver ion doped TiN coatings on Ti substrates. This biphasic system combines the advantages of silver induced bactericidity with the good mechanical properties of TiN. Crystallographic analysis by X-ray diffraction showed that silver was deposited as well in its elementary form as it was incorporated into the crystal lattice of TiN, which resulted in increasing hardness of the TiN-coatings. Elution experiments revealed a continuous release of Ag ions in phosphate buffered saline. The coatings showed significant inhibitory effects on the growth of Staphylococcus epidermidis and Staphylococcus aureus and practically no cell-toxicity in cytocompatibility tests.