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Cold-stretched pressure vessels made from austenitic stainless steel are widely used for storage and transportation of liquefied gases. Compared with conventional pressure vessels, cold-stretched vessels have lots of advantages such as having thin walls, light weight, and low energy consumption. However, pressure vessels can be subjected to alternating loads at cryogenic temperatures, so it is important to investigate the fatigue characteristics of austenitic stainless steel for cold-stretched vessels. This study presents the static and fatigue behavior of austenitic stainless steel 304 sampled from cold-stretched pressure vessels in accordance with the American Society of Mechanical Engineers code. To compare the mechanical properties and fatigue behavior of austenitic stainless steel 304 in as-received and cold-stretched conditions (9 % strain level), tensile and fatigue crack growth tests were performed at room and cryogenic temperatures respectively. Fractography of the fractured specimens was carried out using a scanning electron microscope. Kaltgestreckte Druckbehalter aus Edelstahl werden haufig fur die Lagerung und den Transport von verflussigten Gasen eingesetzt. Im Vergleich zu herkommlichen Druckbehaltern haben kaltgestreckte Gefase viele Vorteile, wie beispielsweise dunne Wande, geringes Gewicht und niedrigen Energieverbrauch. Jedoch konnen Druckbehalter wechselnden Belastungen bei kryogenen Temperaturen ausgesetzt sein, somit ist es wichtig, die Ermudungseigenschaften von Edelstahl fur kaltgestreckte Gefase zu untersuchen. Diese Studie stellt das statische und Ermudungsverhalten von Edelstahl 304 Proben aus kaltgestreckten Druckbehaltern in Ubereinstimmung mit der American Society of Mechanical Engineers Norm dar. Um die mechanischen Eigenschaften und das Ermudungsverhalten von Edelstahl 304 im Ausgangszustand und unter kaltgestreckten Bedingungen (9 % Dehnung) zu vergleichen, wurden Zug- und Ermudungsrisswachstumsversuche bei Raum- und Tiefsttemperaturen durchgefuhrt. Fraktografische Untersuchungen der gebrochenen Proben wurden unter Verwendung eines Rasterelektronenmikroskops durchgefuhrt.

The oncogenic PI3K/Akt/mammalian target of rapamycin (mTOR) signaling axis and its downstream effector, the ribosomal protein S6 kinase 1 (S6K1) play a key role in mediating cell survival in various tumor cells. Here, we investigated the effects of brassinin (BSN), a phytoalexin first identified as a constituent of cabbage, on the PI3K/Akt/mTOR/S6K1 activation, cellular proliferation, and apoptosis in PC-3 human prostate cancer. BSN exerted a significant dose-dependent cytotoxicity and reduced constitutive phosphorylation of Akt against androgen-independent PC-3 cells as compared to androgen-dependent LNCaP cells. Moreover, knockdown of androgen receptor (AR) by small interfering RNA enhanced the potential effect of BSN on induction of apoptosis in LNCaP cells. BSN clearly suppressed the constitutive activation of PI3K/Akt/mTOR/S6K1 signaling cascade, which correlated with the induction of apoptosis as characterized by accumulation of cells in subG1 phase, positive Annexin V binding, TUNEL staining, loss of mitochondrial membrane potential, down-regulation of antiapoptotic and proliferative proteins, activation of caspase-3, and cleavage of PARP. Additionally, BSN could block broad-spectrum inhibition of PI3K/Akt/mTOR/S6K1 axes, and aberrant Akt activation by pcDNA3-myr-HA-Akt1 plasmid could not prevent the observed suppressive effect of BSN on constitutive mTOR activation. Finally, overexpression of Bcl-2 also attenuated BSN-mediated apoptosis in PC-3 cells. Taken together, our findings suggest that BSN can interfere with multiple signaling cascades involved in tumorigenesis and might be provided as a potential therapeutic candidate for both the prevention and treatment of prostate cancer.

In this work the gas evolution behavior and the fining ability of the alkali-free alkaline earth aluminoborosilicate glass batches doped with As2O5 or SnO2 were examined, and the redox behavior of As and Sn ion in the corresponding fined melts was investigated by square wave voltammetry. The evolved gas analysis showed a distinct difference at begin temperature of O2 emission and in evolved O2 volume between glass batches doped with As2O5 and SnO2. One peak due to reduction of As5+ to As3+ or Sn4+ to Sn2+ was shown in the voltammograms. Glass batch doped with SnO2 showed better fining in the first fining zone, but batch doped with As2O5 is more excellent in the overall fining inclusive of the second fining. This difference in fining behavior was discussed by combination of O2 evolution from batches and redox ratio in melts. Finally, it was suggested that the earlier oxidation of As ion in the second fining zone contributed to the excellent fining of melts.

The mixed-alkali effect in ac electrical conductivity has been investigated in 25R2O(Na2O+K2O)-yAl2O3-(75-y)SiO2 melts, with y= 0, 5, 7.5, and 10 mol%, at temperatures of 1000°-1400°C. The results for the molten state show a typical mixed-alkali effect, similar to that exhibited below the transformation temperature. These results imply that the interaction between two different alkali ions is maintained in the molten state. However, the mixed-alkali effect increases as the Al2O3 content increases (in other words, with decreasing nonbridging oxygen content). Such results can be explained in terms of the binding state of AlO4-R+ and -O--R+, based on the conductivity behavior of alkali aluminosilicate melts.

Suspensionnen von Festphasenteilchen in Glasschmelzen verandern deren Fliesverhalten und damit deren Viskositat. Die vorliegende Arbeit behandelt die Abhangigkeit der effektiven Viskositat (ηeff) isotroper Suspensionnen von der Konzentration der Festphansenteilchen. Unabhangig von deren Form liegen die effektiven Viskositaten zwischen oberen und unteren Grenzwerten, deren Konzentrationsabhangigkeit durch Naherungslosungen gegeben ist: obere Grenzwertgleichung: ηeff = ηL (1 − CD)−14 untere Grenzwertgleichung: ηeff = ηL (1 − CD)−3 (ηL = Viskositat der Schmelze; CD = Volumenanteil der Festphasenteilchen). Fur die effektive Viskositat von Suspensionen mit spharischen Festphasenteilchen gilt die untere Grenzwertgleichung. Poren in Sinterglasern verandern ebenfalls deren Flies- und damit Sinter-, Umform- und Kriechverhalten. Die effektive Viskositat poroser Glaser (ηP) als Konzentrationsfunktion ist gegeben durch die Naherungslosungen: obere Grenzwertgleichung: ηP = ηM (1 − P)1.04 untere Grenzwertgleichung: ηP = ηM (1 − P)14 (ηM = Viskositat des porenfreien Glases; P = Porositat). IM Falle spharischer Porositat gilt die Viskositatsgleichung Gemessene Werte der Viskositat diverser Suspensionen sowie von Na2O-SiO2-Schmelzen mit dispergierten festen SiO2-Teilchen und Na2O-GeO2-Schmelzen mit dispergierten GeO2-Teilchen werden ebenso mit berechneten Werten verglichen wie die experimentellen Werte der Viskositat von porosen Sinterglasern mit den entsprechenden theoretischen. In allen Fallen wurde hinreichende, vielfach beste Ubereinstimmung festgestellt. Die Gleichungen liefern praxisrelevante, verlasliche Aussagen sowohl fur Suspensionen wie fur porose Sinterglaser. Qn the viscosity of glass melts and porous sintered glasses Suspensions of solid phase particles in molten glasses modify their flow behavior and therefore their viscosity. This work deals with the dependence of the effective viscosity (ηeff) of isotropic suspensions on the concentration of the solid phase particles. Independently of the shape of the inclusions the values of the effective viscosities lie between upper [ηeff = ηL (1 − CD)−14 ]and lower bounds [ηeff = ηL (1 − CD)−3], where ηL is the viscosity of the molten glass and CD is the volume fraction of solid inclusions. The lower bound is also valid for the effective viscosity of suspensions containing spherical inclusions. Pores present in a glass matrix affect its flow behavior and consequently its creep and sintering behavior. The effective viscosity of porous glasses (ηP) as a function of the volume fraction of pores, or porosity (P), also varies between and upper [ηP = ηM (1 − P)1.04] and a lower bound [ηP = ηM (1 − P)14], where ηM is the viscosity of the nonporous glass matrix. For spherical porosity the equation is: Measured values for the viscosity of different suspensions as reported in the literature as well as own experimental data on two glass-solid systems are compared with the theoretical values predicted by these equations. In a similar way literature data for the viscosity of porous sintered glasses are compared with the respective equations. In all cases a fair agreement between experiment and theory was found in some cases the agreement was excellent. Therefore the presented equations constitute a reliable approach for the prediction of the viscosity of suspensions and porous sintered glasses and since they do not contain fitting parameters, they are of substantial practical relevance (for a comprehensive english treatment of the matter compare Glastechnische Berichte, Proc. Otto-Schott-Colloquium 1994).

Die nicht empirische Auswahl von Sinterhilfen kann mit Hilfe von Zustandsdiagrammen erfolgen. Binare eutektische Zustandsdiagramme ohne Randloslichkeit bieten dafur optimale Voraussetzungen. Ihre Selektion hinsichtlich der Verlaslichkeit darauf, – das die eutektische Temperatur wesentlich niedriger ist als der Schmelzpunkt von SiO2-Glas, – das Randunloslichkeit im SiO2-Bereich vorausgesetzt werden kann, ist durch Vergleich mit theoretischen Werten nach der Schroder-van Laar-Gleichung moglich. Im vorliegenden Fall wurde Rubidiumoxid auf dieser Grundlage als optimale Sinterhilfe ermittelt und eingesetzt. Wie die mit einem Netzsch-Dilatometer durchgefuhrten Sinterstudien zeigen, wird erwartungsgemas mit Rubidium-oxid (≥ 6 Mol-%) die Sintertemperatur von SiO2-Glas auf weniger als 0,5 · Ts gesenkt (Ts = Schmelzpunkt von SiO2-Glas) und liegt damit unterhalb der eutektischen Temperatur. Es handelt sich demnach nicht um Sintern mit flussiger Phase.

The mixed-alkali effect in ac electrical conductivity has been investigated in 25R2O(Na2O+K2O)-yAl2O3-(75-y)SiO2 melts, with y= 0, 5, 7.5, and 10 mol%, at temperatures of 1000°-1400°C. The results for the molten state show a typical mixed-alkali effect, similar to that exhibited below the transformation temperature. These results imply that the interaction between two different alkali ions is maintained in the molten state. However, the mixed-alkali effect increases as the Al2O3 content increases (in other words, with decreasing nonbridging oxygen content). Such results can be explained in terms of the binding state of AlO4-R+ and -O--R+, based on the conductivity behavior of alkali aluminosilicate melts.

The aim of this study is to define a correlation between spatial distribution of functional feeding groups of aquatic insects and their habitat types in the Geum River based on the theory of River Continuum Concept (RCC). For that object we had classified habitat types of the study area according to various environmental factors and examined closely their distribution characteristics by correlation analysis between biota community and the environmental factors. And then, a probabilistic method named Frequency Ratio Model (FRM) and spatial analysis function of GIS were applied to produce a predictive distribution map of biota community considering their distribution characteristics according to the environmental factors as related variables. As a result, 6 major environmental factors that might affect the classification of habitat types were extracted. Finally, we had compared the predicted distribution map with prior survey database from other researches and then could find out a high correlation between them. The results of this study might be used to develop a new estimation method for aquatic ecosystem with functional feeding groups of aquatic insects and also be used as preliminary data for conservation and restoration of stream habitats.

We prepared MgO films using e-beam deposition and polycrystalline MgO pellets and oxygen flow rates of 50 sccm and 100 sccm. These films were examined in gas discharge tests at different temperatures. The dependence of the discharge delay time on film temperature was smaller for the film grown at 100 sccm O2 flow compared to the film grown at 50 sccm. Their wall charges were also measured. This revealed that MgO films grown at 100 sccm had more wall charges. The analysis showed a difference in surface roughness. MgO films with a larger surface roughness had more wall charge.