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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 influence of K2O/(MgO + K2O) on some melt properties, including crystallization during cooling of melts and glass-forming ability, was investigated in the Li2O–Al2O3–SiO2 system with low Al2O3 content. The dependence of viscosity on K2O/(MgO + K2O) above 1000 °C showed a monotonic decrease due to the reduction of [MgO4] concentration and the conductivity also decreased due to the larger ion radius of K. The temperature dependence of conductivity for all melts showed an abrupt change at one temperature due to crystallization in which temperature of crystallization decreases with increase of K2O. The crystallization behavior near liquidus temperature was studied quantitatively by calculating the crystal volume fraction from apparent viscosity value. The glass-forming ability of the melts was discussed by using data related with viscosity and crystallization. Finally, it was suggested that the melts with K2O/(MgO + K2O) ⩾ 0.75 have a good glass-forming ability.

The redox behavior of various elements (Fe, Sb, Ce, Ti, Zn) was investigated in alkali–alkaline earth-silica CRT (Cathode ray tube: TV panel) model glass melts using the square-wave voltammetry (SWV). The current–potential curve, so called voltammogram, was produced at temperature range of 1000–1400 °C under the scanned potential between 0 and –800 mV at 100 Hz. The Fe, Ti and Zn doped melts exhibited one peak due to reduction reaction. In the case of the Sb doped melts, two traces doubted as peak were found in the voltammogram at low temperature while only one peak existed at high temperature. The peak potential was shifted to the negative direction with decrease of temperature, however, its temperature dependence showed linearity. On the other hand, no peak was found in voltammogram of the melts doped with Ce. Based on the temperature dependence of the peak potential, standard enthalpy (ΔH0) and standard entropy (ΔS0) for the reduction of Fe3+ to Fe2+, Sb3+ to Sb0 and Zn2+ to Zn0 in CRT model glass melts were calculated.

Novel red phosphorescent iridium complex with two phenyl-isoquinoline ligands and one 2-acetyl-cyclopentanone ligand (IR-PIQCP) was designed and synthesized. The electroluminescent (EL) characteristics of IR-PIQCP were evaluated in the EL device. The three kinds of EL devices were fabricated by the vacuum deposition method, and the layer-structures of the devices were ITO/NPD/IR-PIQCP (5%), IR-PIQCP (10%) or IR-BTPAC (10%) in CBP/Balq/Alq/LiF/Al. Emission characteristics of the IR-PIQCP (5%) and IR-PIQCP (10%) devices were about 570 cd/m2 and 550 cd/m2 at 11 mA/cm2 at the same current density respectively. The EL spectra of the IR-PIQCP (5%) and IR-PIQCP (10%) devices were detected at about 627 nm and 629 nm as the maximum peak with red phosphorescence.

The crystal nucleation effect in lithium aluminosilicate glasses was investigated by the viscosity measurement with aid of the fiber elongation method. The abrupt increase of viscosity due to the crystallization of glass was observed in viscosity–temperature curve but the minimum viscosity temperature (Tη) related with crystallization showed a strong dependence on the nucleation state such as nucleation temperature, nucleation time and heating rate. The results by viscosity agreed well with those of DTA. The nucleation effect on the microstructure of glass-ceramics was also discussed. Finally, the nucleation effect on the crystallization kinetics was approached quantitatively by calculating the crystal volume from viscosity value.

The mineralogical compositions of bituminous fly ashes varied depending on the locations of hoppers attached to an electrostatic precipitator in coal-fired power plant. From the first hopper towards the third hopper, that is, as the particles of fly ashes decreased in size, the content of glassy phase increased, while the amount of α-quartz decreased. When the boiler was operated at full load in comparison with operating at half load, the content of glassy phase was greater. The chemical compositions of the glassy phase showed a tendency in Al 2 O 3 increase, while SiO 2 decreased as the particles size became smaller.

Novel silicon-based copolymers show the UV-visible strong absorption bands around 347∼387 nm. Their maximum photoluminescence (PL) wavelengths for silicon-based copolymers appeared around 420∼480 nm in the blue region. The present copolymers with a relatively short π-conjugation length exhibit blue light-emitting diodes (LED) at the low operating voltages, due to the reduction of the LUMO level in luminescent polymers by introducing silicon atoms in luminescent polymers as well as the d-orbital participation of silicon atoms.

The viscosities of the four series of mixed alkali glass melts such as 25(Na2O+K2O)⋅75SiO2, 25(Na2O+K2O)⋅5Al2O3⋅70SiO2, 25(Na2O+K2O)⋅7.5Al2O3⋅67.5SiO2 and 25(Na2O+K2O)⋅10Al2O3⋅65SiO2 as well as their Tg were measured to elucidate a relation between property behaviors and mixed alkali effect models. The base mixed alkali glass melts (25R2O⋅75SiO2) showed a mixed alkali effect, namely viscosity minima at the composition K2O/R2O≈0.25, which become weaker as temperature increases. The activation energy for the viscous flow of this base glass melts showed also a minimum at this composition. However, the mixed alkali effect disappeared, as SiO2 is substituted by Al2O3. This implies that the nonlinearity disappears with decreasing nonbridging oxygen content. In the case of Tg no clear tendency with respect to the Al2O3 content was found.By comparison of the present work with the earlier work of resistivity, two distinct differences between the mixed alkali effects in viscosity and electrical conductivity were found. From these results, it was concluded that the mechanism for the mixed alkali effect in both properties should be treated independently.

Gel powders in a binary glass-forming SiO 2 TiO 2 system with compositions of 2–8 mol% TiO 2 were synthesized by hydrolysis of metal alkoxides in a sol-gel process. The sintering behavior of calcined gel powders was investigated with a dilatometer. Their sintering stage could be divided into three by two characteristic temperatures ( T sin and T cry ) on the shrinkage curve. It was found that the sintering temperature, T sin , in the second stage decreases with increase of TiO 2 content. Considering the effect of viscous flow on the sintering of glass powders, these results mean that the addition of TiO 2 into silica glass reduces the viscosity of this glass. On the basis of these results, it was concluded that the formation of [TiO 4 ] units in the SiO 2 network makes the whole glass network rather weaker than stronger. The correlation between sintering temperature and thermal expansion coefficient of these compositions was also discussed.

The sintering of glass powder compacts was studied by dilatometer in the (25 -x) Na2O–xK2O–75SiO2glass system. The dilatometrically determined sintering temperature (Tsin) at constant heating rate decreases and the shrinkage at isothermal sintering increases when Na2O is replaced by K2O up to the mole fraction of K2O/(Na2O + K2O) = 0.5. This is due to the decrease in viscosity and means that sintering can be possibly accelereted by introduction of mixed alkali oxides in this system. According to calculation using the VFT-equation, the viscosity value atTsinis almost independent of glass composition. From these results it may be supposed that the dilatometrically determined sintering begin temperature (Tsin) can be a characteristic point for the sintering of glass.

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.

A new class of silicon-containing poly ( p -phenylenevinylene) -related polymers with a uniform π -conjugated segment, regulated by organosilicon units, shows two strong absorption bands around 312 and 352 nm, corresponding to the π-π * transition of the carbazole unit and the conjugated segments, respectively. The present polymers exhibit two strong photoluminescent peaks in the blue range of 420–480 nm and the green region of 540 nm. The latter is attributed to the carbazole segment. Their electroluminescence (EL) spectra similarly show two strong emissive bands in the blue region and the yellow region. The current-voltage ( I–V ) curve of a typical light-emitting device fabricated with a Al/SiPVKPPV/ITO glass structure shows a typical rectifying characteristic with a threshold voltage of 12 V.

Novel silicon-based copolymers exhibit the ground-state absorption band maxima around 340390 nm and their photoluminescence in blue region. The blue light-emitting diodes (LED) fabricated with the copolymers could be successfully operated at the considerable low voltages compared to those for other blocked PPV copolymers. The introduction of both silicon and carbazole moieties into PPV main chain results in an interesting dependencies of EL spectral feature on the operating voltage for LED. In order to know the origin of the dependence, we have investigated PL and its excitation spectra of the silicon based copolymeric systems.