Browsing by Author "Jiang, L"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- ItemCLIC proteins, ezrin, radixin, moesin and the coupling of membranes to the actin cytoskeleton: A smoking gun?(Elsevier, 2014-02-01) Jiang, L; Phang, JM; Yu, J; Harrop, SJ; Sokolova, AV; Duff, AP; Wilik, KE; Alkhamici, H; Breit, SN; Valenzuela, SM; Brown, LJ; Curmi, PMGThe CLIC proteins are a highly conserved family of metazoan proteins with the unusual ability to adopt both soluble and integral membrane forms. The physiological functions of CLIC proteins may include enzymatic activity in the soluble form and anion channel activity in the integral membrane form. CLIC proteins are associated with the ERM proteins: ezrin, radixin and moesin. ERM proteins act as cross-linkers between membranes and the cortical actin cytoskeleton. Both CLIC and ERM proteins are controlled by Rho family small GTPases. CLIC proteins, ERM and Rho GTPases act in a concerted manner to control active membrane processes including the maintenance of microvillar structures, phagocytosis and vesicle trafficking. All of these processes involve the interaction of membranes with the underlying cortical actin cytoskeleton. The relationships between Rho GTPases, CLIC proteins, ERM proteins and the membrane:actin cytoskeleton interface are reviewed. Speculative models are proposed involving the formation of localised multi-protein complexes on the membrane surface that assemble via multiple weak interactions. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. © 2013, Elsevier B.V.
- ItemThe effect of grain size and dislocation density on the tensile properties of Ni-SiCNP composites during annealing(Springer Nature, 2016-02-12) Yang, C; Huang, HF; Thorogood, GJ; Jiang, L; Ye, XX; Li, ZJ; Zhou, XTThe grain size refinement, enhancement of mechanical properties, and static recrystallization behavior of metallic nickel-silicon carbide nano-particle (Ni-3wt.%SiCNP) composites, milled for times ranging from 8 to 48 h have been examined. One set of Ni-SiCNP composite samples were annealed at 300 °C for 250 h, while the other set of samples were maintained at room temperature for control purposes (reference). The electron backscatter diffraction results indicate that the grain size of the annealed Ni-SiCNP composite was refined due to grain restructuring during static recrystallization. The x-ray diffraction results indicate that low-temperature annealing effectively reduced the density of dislocations; this can be explained by the dislocation pile-up model. Additionally, the tensile tests indicated that the annealed Ni-SiCNP composite had a significant increase in strength due to an increase of the Hall–Petch strengthening effect with a slight increase in the total elongation. The decrease of dislocation pile-up in the grain interiors and the increase in grain boundary sliding are assumed to be the main mechanisms at play. The relationship between the microstructural evolution and the variation of tensile properties is examined in this study. © 2016 ASM International. Published by Springer Nature.
- ItemThe effect of molybdenum on clustering and precipitation behaviour of strip-cast steels containing niobium(Elsevier B. V., 2019-12) Jiang, L; Marceau, RKW; Guan, B; Dorin, T; Wood, K; Hodgson, PD; Stanford, NTwo high-strength low-alloy (HSLA) steels containing Nb-carbonitrides were produced, one contained Mo and the other was Mo-free. The alloys were produced by simulated direct strip casting, and were fully bainitic in the as-cast condition. Isothermal ageing treatments were carried out to precipitate harden the alloy, and the strength was measured using a shear punch test. The dislocation density was measured with X-ray diffraction (XRD), and was found to be larger in the alloy containing Mo in all ageing conditions. Atom probe tomography (APT) showed the presence of solute clusters in the as-cast condition, and the addition of Mo increased both size and volume fraction of these clusters. The solute clusters provided significant strengthening increments of up to 112 MPa, and cluster strengthening was larger in the Mo-containing alloy. Precipitation of Nb-carbonitrides was observed after longer ageing times, which were refined by the addition of Mo. This was attributed to the higher dislocation density that increased the number of nucleation sites. Precipitate chemistry was similar for both alloys, and contrary to some literature reports, minimal Mo was observed to segregate to the precipitates. A thermodynamic rationale is presented which describes the reasons that Mo segregates to the Nb-carbide in some alloys but not in others, despite the alloy chemistries being relatively similar. © 2019 Acta Materialia Inc.
- ItemEffect of molybdenum on the precipitation in ferritic niobium-containing steels produced by strip casting(Australian Institute of Nuclear Science and Engineering (AINSE), 2020-11-11) Jiang, L; Wood, K; Dorin, T; Marceau, RKW; Stanford, NMolybdenum (Mo) is often alloyed into the steels containing niobium (Nb), in order to enhance the formation of harder microstructures, such as bainite and acicular ferrite, and denser and finer precipitates. However, the effect of Mo on the nano-precipitates formed in the ferrite of Nb steels is still subject to debate, mostly due to its experimentally challenging nature. In addition, direct strip casting is a revolutionary casting technique that integrates casting and subsequent rolling together with rapid solidification and cooling rates, which not only simplifies the process, but also confers superior energy-saving as compared to conventional alloy thermomechanical processing. In this work, therefore, we have studied the effect of Mo on the precipitation in the ferrite of a Nb-containing micro-alloyed steel produced by strip casting using various advanced characterisation techniques. Isothermal ageing treatments were carried out at 650 ℃ up to 10,000 s to form precipitates, and the strength was measured using shear punch test. Transmission electron microscopy (TEM) observation showed that precipitates were formed along dislocations in both steels with and without Mo. Atom probe tomography (APT) analyses revealed that the addition of Mo increased both size and volume fraction of solute clusters after short ageing times, which provided a much higher cluster strengthening. Precipitation of Nb-rich carbonitrides were found after longer ageing treatments. However, no significant Mo was observed to segregate to the precipitate. Small-angle neutron scattering (SANS) results indicated that the addition of Mo reduced the average precipitate size. X-ray diffraction (XRD) results suggested. © The Authors
- ItemEvaluating irradiation dose for sterility induction and quality control of mass-produced fruit fly cactrocera tryoni (Diptera: Tephritidae)(Oxford University Press, 2014-06-01) Dominiak, BC; Sundaralingam, S; Jiang, L; Fanson, BG; Collins, SR; Banos, C; Davies, JB; Taylor, PWThe sterile insect technique has been routinely used to eradicate fruit fly Bactrocera tryoni (Froggatt) incursions. This study considers whether fly quality in a mass-rearing facility can be improved by reducing irradiation doses, without sacrificing reproductive sterility. Pupae were exposed to one of five target irradiation dose ranges: 0, 40–45, 50–55, 60–65, and 70–75 Gy. Pupae were then assessed using routine quality control measures: flight ability, sex ratio, longevity under nutritional stress, emergence, and reproductive sterility. Irradiation did not have a significant effect on flight ability or sex ratio tests. Longevity under nutritional stress was significantly increased at 70–75 Gy, but no other doses differed from 0 Gy. Emergence was slightly reduced in the 50–55, 60–65, and 70–75 Gy treatments, but 40–45 Gy treatments did not differ from 0 Gy, though confounding temporal factors complicate interpretation. Reproductive sterility remained acceptable (>99.5%) for all doses— 40–45 Gy (99.78%), 50–55 Gy (100%), 60–65 Gy (100%), and 70–75 Gy (99.99%). We recommend that B. tryoni used in sterile insect technique releases be irradiated at a target dose of 50–55 Gy, providing improved quality and undiminished sterility in comparison with the current 70–75 Gy standard while also providing a substantial buffer against risk of under dosing. © 2014, Oxford University Press
- ItemInvestigate the effect of molybdenum on precipitation in coiled strip cast niobium steels using correlative microscopy(Australian Microscopy and Microanalysis Society, 2016-02-04) Jiang, L; Dorin, T; Marceau, RKW; Wood, K; Hodgson, P; Stanford, NSteels containing both Nb and Mo have been reported to exhibit superior strength as compared to those containing only Nb. This has been explained by the formation of harder microstructures, such as bainite and acicular ferrite, and denser and finer precipitates promoted by the addition of Mo. For further improvement of this strengthening method, a fundamental understanding of the effect of Mo on precipitation in steels is necessary. Transmission electron microscopy (TEM) is commonly used for precipitation studies and provides direct imaging of the precipitates, however it only allows local observation and it is thus non statistical by nature and makes it difficult to estimate precipitates volume fraction. On the other hand, small angle neutron scattering (SANS) can be used as a statistical technique to quantitatively study precipitation. Consequently, TEM and SANS provide complementary information and are thus powerful when used in combination. SANS measurement was used to determine the size distribution and volume fraction of particles. Meanwhile, TEM observation was performed to obtain the distribution, morphology, chemistry and size of particles on the samples investigated by SANS. In this research, the effect of Mo on precipitate formation is studied in steels processed with the recently developed direct strip casting process and subsequent coiling treatment. Direct strip casting is a revolutionary casting technique that integrates casting and subsequent rolling together with rapid solidification and cooling rates, which not only simplifies the process, but also confers superior energy-saving as compared to conventional alloy thermomechanical processing. The strip cast samples were isothermally coiled at 700 ̊C for durations up to 10000 seconds. TEM results show that interphase precipitates were formed in both alloys and the size of particles were in the range of 10 nm. Additionally, SANS was used to quantify the precipitate size and volume fraction evolution during coiling.
- ItemNatural ageing behaviour in Al-Cu alloys containing Sc and Z(Australian Nuclear Science and Technology Organisation, 2021-11-24) Jiang, L; Wood, K; Knott, RB; Sokolova, AV; Dorin, TThe 2xxx series Al-Cu alloys have been extensively used as engineering structures and components of lightweight vehicles due to their excellent strength-to-weight ratio. Recent research has demonstrated that further substantial enhancement in the strength of Al-Cu alloys could be achieved by adding Sc and Zr by forming nano-sized Al3(Sc, Zr) dispersoids. However, further development and manufacturing of these new Sc and Zr-containing Al-Cu alloys are limited by a lack of basic understanding of the effect of Al3(Sc, Zr) dispersoids on the microstructural evolution during room temperature storage after quenching from solution treatment (called natural ageing). In this work, therefore, we have studied the effect of Al3(Sc, Zr) dispersoids on natural ageing behaviour in an Al-4wt.%Cu-0.1wt.%Sc-0.1wt.%Zr alloy using small-angle neutron and x-ray scattering (SANS and SAXS). The hardness measurement shows that the presence of Al3(Sc, Zr) dispersoids significantly delays the natural ageing kinetics of Al-Cu alloys. SANS was used to quantify the size distribution of Al3(Sc, Zr) dispersoids which is ~ 25 ± 3 nm. In-situ SAXS results show that the presence of Al3(Sc, Zr) dispersoids results in a significant delay in the solute clustering formation during natural ageing. This is attributed to the suppression of the natural ageing kinetics in the Al-Cu-Sc-Zr alloys. These results were confirmed by differential scanning calorimetry (DSC) and high resolution transmission electron microscopy (TEM). The suppression mechanism is hypothesized to come from the dispersoids and Sc solute acting as vacancy sinks which slows down the diffusion of solute at room temperatures. © 2021 The Authors