Umformtechnische Halbzeug- sowie Fertigteilherstellung und Bauteilerprobung von TiAl-Motorkomponenten Abschlussbericht

Available from TIB Hannover: F00B774 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung (BMBF), Bonn (Germany)DEGerman

MSKOMP - MoSi_2-Komposite fuer Hochtemperaturanwendungen in korrosiven und oxidativen Atmosphaeren Abschlussbericht

Composite materials consisting of a matrix of MoSi_2 having a melting point above 2000 C and ceramic inclusions provide high a potential for high temperature application. Due to the formation of a thin, self healing SiO_2 film this material class is of particular interest for high temperature application in corrosive and oxidative atmospheres. The production was to be established by a reaction powder technological process with subsequent sintering with and without pressure. The samples obtained were to be tested in oxidizing atmosphere at high temperatures. During the project the economically feasible production of composites with a matrix of MoSi_2 via a reaction powder technological process could be demonstrated. An optimization in terms of purity which is a premise for high temperature application, is obligatory. (orig.)Kompositwerkstoffe mit einer Matrix aus MoSi_2 mit einem Schmelzpunkt ueber 2000 C und keramischen Einlagerungen bieten ein grosses Potenzial fuer den Einsatz bei hohen Temperaturen. Aufgrund der Ausbildung duenner, selbstheilender Deckschichten aus SiO_2 ist diese Werkstoffklasse insbesondere fuer den Hochtemperatureinsatz in korrosiven und oxidativen Atmosphaeren interessant. Die Herstellung sollte durch einen reaktionspulvertechnologischen Prozess mit anschliessender Sinterung mit und ohne Anwendung von Druck erfolgen. Die gewonnenen Proben sollten in oxidativer Atmosphaere bei hohen Temperaturen getestet werden. Im Rahmen des Projekts konnte gezeigt werden, dass die Herstellung von Kompositen mit MoSi_2-Matrix ueber einen reaktionspulvertechnologischen Prozess wirtschaftlich anwendbar ist. Hier bedarf es hinsichtlich der fuer die Verwendung bei hoher Temperatur notwendigen Reinheit noch einer Optimierung. (orig.)SIGLEAvailable from TIB Hannover: F03B492 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

PVD-Beschichtung von Metalloberflaechen zur Verschleissminimierung von Polyaethylen im kuenstlichen Kniegelenk Abschlussbericht

SIGLEAvailable from TIB Hannover: F99B949+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

An AM-induced, MYB-family gene of Lotus japonicus (LjMAMI) affects root growth in an AM-independent manner

The interaction between legumes and arbuscular mycorrhizal (AM) fungi is vital to the development of sustainable plant production systems. Here, we focus on a putative MYB-like (LjMAMI) transcription factor (TF) previously reported to be highly upregulated in Lotus japonicus mycorrhizal roots. Phylogenetic analyses revealed that the protein is related to a group of TFs involved in phosphate (Pi) starvation responses, the expression of which is independent of the Pi level, such as PHR1. GUS transformed plants and quantitative reverse transcription PCR revealed strong gene induction in arbusculated cells, as well as the presence of LjMAMI transcripts in lateral root primordia and root meristems, even in the absence of the fungus, and independently of Pi concentration. In agreement with its putative identification as a TF, an eGFP-LjMAMI chimera was localized to the nuclei of plant protoplasts, whereas in transgenic Lotus roots expressing the eGFP-LjMAMI fusion protein under the control of the native promoter, the protein was located in the nuclei of the arbusculated cells. Further expression analyses revealed a correlation between LjMAMI and LjPT4, a marker gene for mycorrhizal function. To elucidate the role of the LjMAMI gene in the mycorrhizal process, RNAi and overexpressing root lines were generated. All the lines retained their symbiotic capacity; however, RNAi root lines and composite plants showed an important reduction in root elongation and branching in the absence of the symbiont. The results support the involvement of the AM-responsive LjMAMI in non-symbiotic functions: i.e. root growth

Phase Transition and Ordering Temperatures of TiAl-Mo Alloys Investigated by In-Situ Diffraction Experiments

High frequency ultrasonography (HFUS) is a non-invasive, low risk method which can provide real-time visual information regarding different processes in cutaneous tissue. The goal of this study is to compare the accuracy of HFUS in determining depth and width of basal cell carcinoma (BCC) lesions compared with histopathology as a reference standard.The depth and width of 56 primary BCCs in various locations were measured in vivo using the ultrasound system device Digital Taberna Promedica (Luneburg, FRG DUB 20 Ultrasound Scanner), with a 50-MHz hand-held transducer and compared with the depth and width reported in histopathologic examination of these lesions after complete excision. The intraclass correlation coefficient (ICC) was calculated using a one-way ANOVA table to compare measured dimensions for the same tumors with the two diagnostic methods.The mean depth of tumor in HFUS (1353.68 ± 656.456 microns) was lower than the amount measured by the dermatopathologist (1560.71 ± 1044.323 microns). However, the difference was not statistically significant (P > 0.05). The means of largest diameter of tumors in HFUS and pathology were 5996.77 ± 2271.783 and 3891.07 ± 1995.452 microns, respectively (P < 0.001). There was a low correlation in diameter (r = 0.27, P < 0.05) and a moderate correlation in depth (r = 0.45, P < 0.001) of BCCs between these two methods.HFUS may be a useful method to assess the dimensions of BCC prior to surgery

Modelling Ammonium Transporters in Arbuscular Mycorrhiza Symbiosis

The Stochastic Calculus ofWrapped Compartments (SCWC) is a recently proposed variant of the Stochastic Calculus of Looping Sequences (SCLS), a language for the representation and simulation of biological systems. In this work we apply SCWC to model a newly discovered ammonium transporter. This transporter is believed to play a fundamental role for plant mineral acquisition, which takes place in the arbuscular mycorrhiza, the most wide-spread plant-fungus symbiosis on earth. Investigating this kind of symbiosis is considered one of the most promising ways to develop methods to nurture plants in more natural manners, avoiding the complex chemical productions used nowadays to produce artificial fertilizers. In our experiments the passage of NH3 / NH+4 from the fungus to the plant has been dissected in known and hypothetical mechanisms; with the model so far we have been able to simulate the behavior of the system under different conditions. Our simulations confirmed some of the latest experimental results about the LjAMT2;2 transporter. Moreover, by comparing the behaviour of LjAMT2;2 with the behaviour of another ammonium transporter which exists in plants, viz. LjAMT1;1, our simulations support an hypothesis about why LjAMT2;2 is so selectively expressed in arbusculated cells