Universidad de Granada
Aprobaci??n del M??ster Propio en Regulaci??n Administrativa: Medio Ambiente y Derecho Administrativo de la Empresa. 1?? Edici??n 11/M/037, aprobado en Sesi??n Extraordinaria del Consejo de Gobierno celebrado el 26 de mayo de 2011.
The method and test devices for the study of the effect of multicycle loadings change in a wide range of temperatures and amplitudes on tensile stress-strain diagrams have been developed. Using the method developed the effect of cyclic loadings on diagrams of instant expansion of heat resisting alloys EhI867, EhI827, EhI698VD, EhI437B in the temperature range from 20 to 1000 deg C is studied. It is shown, that the developed method of tensile stress-strain diagram recording during cyclic loading permits to obtain new data to evaluate the properties of materials, operating under complex conditions of loading
The distribution of non-metallic inclusions in billets of carbon steels, alloyed steels (Kh18N9T) and heat-resistant nickel alloys (EhI437B, EhP109) has been studied. Billets of square and round cross sections have been casted using horisontal continuous-casting machines. Methods of chemical, metallographic, petrographic and X-ray analyses have been applied in investigations. A rise in the content of non-metallic inclusions has been observed in the upper zones of billet cross sections. Inclusions in carbon steels are mainly represented by α-A2O3 in stainless steels - by TiO and TiN, in nickel alloys - by TiN and AlN. Investigations into nitrogen and oxygen distribution have proved the data obtained. Inclusions and gases have been distributed evenly over billet length. Liquid metal blowing with argon and the application of coper-graphite dies have permitted to obtain a metal with an uniform oxide and nitride distribution over billet cross section and lentgh
Winkler, Stephan R.; Eigl, Rosmarie; Forstner, Oliver; Martschini, Martin; Steier, Peter; Sterba, Johannes H.; Golser, Robin
Neutron activation analysis using decay counting of the activated element is a well-established method in elemental analysis. However, for chlorine there is a better alternative to measuring decay of the short-lived activation product chlorine-38 (t1/2 = 37.24 min) - accelerator mass spectrometry (AMS) of 36Cl: the relatively high neutron capture cross section of chlorine-35 for thermal neutrons (43.7 b) and combined the AMS technique for chlorine-36 (t1/2 = 301 ka) allow for determination of chlorine down to ppb-levels using practical sample sizes and common exposure durations. The combination of neutron activation and AMS can be employed for a few other elements (nitrogen, thorium, and uranium) as well. For bulk solid samples an advantage of the method is that lab contamination can be rendered irrelevant. The chlorine-35 in the sample is activated to chlorine-36, and surface chlorine can be removed after the irradiation. Subsequent laboratory contamination, however, will not carry a prominent chlorine-36 signature. After sample dissolution and addition of sufficient amounts of stable chlorine carrier the produced chlorine-36 and thus the original chlorine-35 of the sample can be determined using AMS. We have developed and applied the method for analysis of chlorine in steel samples. The chlorine content of steel is of interest to nuclear industry, precisely because of above mentioned high neutron capture cross section for chlorine-35, which leads to accumulation of chlorine-36 as long-term nuclear waste. The samples were irradiated at the TRIGA Mark II reactor of the Atominstitut in Vienna and the 36Cl-AMS setup at the Vienna Environmental Research Accelerator (VERA) was used for 36Cl/Cl analysis.
Two cuticle-degrading proteases Ver112 and PL646 were purified from the nematophagous fungi L. psalliotae and P. lilacinus, respectively. The protease Ver112 and a complex between PL646 and a tetrapeptide inhibitor were crystallized. Diffraction data were collected to 1.65 and 2.2 Å resolution, respectively. Cuticle-degrading proteases are extracellular subtilisin-like serine proteases that are secreted by entomopathogenic and nematophagous fungi. These proteases can digest the host cuticle during invasion of an insect or nematode and serve as a group of important virulence factors during the infection of nematodes by nematophagous fungi. To elucidate the mechanism of interaction between the proteases and the nematode cuticle, two cuticle-degrading proteases, Ver112 from Lecanicillium psalliotae (syn. Verticillium psalliotae) and PL646 from Paecilomyces lilacinus, were studied. The Ver112 protein and the complex between PL646 and the substrate-like tetrapeptide inhibitor methoxysuccinyl-Ala-Ala-Pro-Val-chloromethyl ketone (MSU-AAPV) were crystallized using the hanging-drop vapour-diffusion method at 289 K. The crystals were analyzed by X-ray diffraction to resolutions of 1.65 and 2.2 Å, respectively. These analyses identified that crystals of Ver112 belonged to space group P212121, with unit-cell parameters a = 43.7, b = 67.8, c = 76.3 Å, α = β = γ = 90°. In contrast, crystals of the PL646–MSU-AAPV complex belonged to space group P21, with unit-cell parameters a = 65.1, b = 62.5, c = 67.6 Å, β = 92.8°