The production of ultrafine ferrite in low-carbon steel by strain-Induced transformation

An investigation into the production of ultrafine (1 µm) equiaxed ferrite (UFF) grains in low-carbon steel was made using laboratory rolling, compression dilatometry, and hot torsion techniques. It was found that the hot rolling of thin strip, with a combination of high shear strain and high undercooling, provided the conditions most suitable for the formation of this type of microstructure. Although high strains could be applied in compression and torsion experiments, large volume fractions of UFF were not observed in those samples, possibly due to the lower level of undercooling achieved. It is thought that ferrite refinement was due to a strain-induced transformation process, and that ferrite grains nucleated on parallel and linear deformation bands that traversed austenite grains. These bands formed during the deformation process, and the undercooling provided by the contact between the strip and the work rolls was sufficient to drive the transformation to homogeneous UFF grains.

The production of ultrafine ferrite during hot torsion testing of a 0.11 Wt Pct C steel

Ultrafine ferrite grain sizes were produced in a 0.11C-1.6Mn-0.2Si steel by torsion testing isothermally at 675 °C after air cooling from 1250 °C. The ferrite was observed to form intragranularly beyond a von Mises equivalent tensile strain of approximately 0.7 to 0.8 and the number fraction of intragranular ferrite grains continued to increase as the strain level increased. Ferrite nucleated to form parallel and closely spaced linear arrays or “rafts” of many discrete ultrafine ferrite grains. It is shown that ferrite nucleates during deformation on defects developed within the austenite parallel to the macroscopic shear direction (i.e., dynamic strain-induced transformation). A model austenitic Ni-30Fe alloy was used to study the substructure developed in the austenite under similar test conditions as that used to induce intragranular ferrite in the steel. It is shown that the most prevalent features developed during testing are microbands. It is proposed that high-energy jogged regions surrounding intersecting microbands provide potential sites for ferrite nucleation at lower strains, while at higher strains, the walls of the microbands may also act as nucleation sites.

Homophobia and the production of shame: young people and same sex attraction

Research among same-sex attracted young people in Western cultures has described a minority group of adolescents whose sexuality is negated by the significant institutions and people in their lives. Very often, there is a silence in the family and at school about same-sex sexuality and when a young person's homosexuality is suspected or disclosed s/he suffers from denial, discrimination and abuse. Not surprisingly, living in hostile environments leaves such young people at high-risk of drug abuse, depression and suicide. This paper describes some of the ways young people resist being positioned in these negative ways. Using autobiographical stories from 200 same-sex attracted young Australians, we document the discursive field of sexuality in which these young people struggle to construct positive identities. Young people were well aware of dominant discourses which characterized homosexuality as 'evil, diseased and unnatural'. Yet they use different strategies to fault, deflect and discount these negative understandings and to highlight other discourse which positions them positively.

Photochemical Production of MicromolarSuperoxideStandards in Aqueous SolutionT

Superoxide(O2-) is a reactive free radical that rapidly undergoes disproportionation to hydrogen peroxide and oxygen. This property makes preparation of superoxide standard for instrument calibration difficult. McDowell et al. (1983) showed photolysis of ketone and alcohol as a convenient method to generate superoxide through triplet and radical intermediates reacting with molecular oxygen. This study expands on this past work and investigates detailed mechanism of the reaction.

Efficient production of ZnO nanowires by a ball milling and annealing method

ZnO powder was mechanically milled in a ball mill. This procedure was found to greatly increase its evaporation ability. The anomalous evaporation behaviour was caused by the disordered structure of the milled material and was not related to the increase in its surface area after milling. ZnO nanowires were synthesized by evaporation of this milled precursor. Nanowires with smooth and rough surfaces were present in the sample; the latter morphology was dominant. A green emission band centred at 510 nm was dominant in the cathodoluminescence spectrum of the nanowires.

Optimization of process parameters for the production of naringinase by Aspergillus niger MTCC 1344

Aspergillus niger MTCC 1344 was used to produce extracellular naringinase in a complex (molasses, yeast extract and salts) medium. An initial medium pH 4.5 and cultivation temperature 30 °C were optimal for enzyme production. Among various carbon and organic nitrogen sources used, molasses and peptone were the most effective for enzyme yield. The rate of enzyme production was enhanced when metal ions were added to the medium. Fermentation conditions are described which produced a higher rate of enzyme synthesis. An increase in initial sugar concentration from 6 to 10 g l⁻¹ in the fermentation medium produced decreased naringinase synthesis while cell mass growth increased with the increase of sugar concentration. At a higher sugar level (10 g l⁻¹) the production of cell mass decreased.

Production of high fructose syrup from asparagus inulin using immobilized exoinulinase from Kluyveromyces marxianus YS-1

Extracellular exoinulinase from Kluyveromyces marxianus YS-1, which hydrolyzes inulin into fructose, was immobilized on Duolite A568 after partial puriWcation by ethanol precipitation and gel exclusion chromatography on Sephadex G-100. Optimum temperature of immobilized enzyme was 55 °C, which was 5 °C higher than the free enzyme and optimal pH was 5.5. Immobilized biocatalyst retained more than 90% of its original activity after incubation at 60 °C for 3 h, whereas in free form its activity was reduced to 10% under same conditions, showing a signiWcant improvement in the thermal stability of the biocatalyst after immobilization. Apparent Km values for inulin, raYnose and sucrose were found to be 3.75, 28.5 and 30.7 mM, respectively. Activation energy (Ea) of the immobilized biocatalyst was found to be 46.8 kJ/mol. Metal ions like Co2+ and Mn2+ enhanced the activity, whereas Hg2+ and Ag2+ were found to be potent inhibitors even at lower concentrations of 1 mM. Immobilized biocatalyst was eVectively used in batch preparation of high fructose syrup from Asparagus racemosus raw inulin and pure inulin, which
yielded 39.2 and 40.2 g/L of fructose in 4 h; it was 85.5 and 92.6% of total reducing sugars produced, respectively.

Optimization of medium and process parameters for the production of inulinase from a newly isolated Kluyveromyces marxianus YS-1

A newly isolated strain of Kluyveromyces marxianus YS-1 was used for the production of extra cellular inulinase in a medium containing inulin, meat extract, CaCl₂ and sodium dodecyl sulphate (SDS). Fermentation medium pH 6.5, cultivation temperature 30 °C and 5% (v/v) inoculum of 12 h-old culture were optimal for enzyme production (30.8 IU/ml) with a fermentation time of 72 h at shake flask level. Raw inulin (2%, w/v) extracted from dahlia tubers by processing at 15 kg/cm² for 10 min was optimum for bioreactor studies. Maximum enzyme production (55.4 IU/ml) was obtained at an agitation rate of 200 rpm and aeration of 0.75 vvm in a stirred tank reactor with a fermentation time of 60 h.

Production of inulinase from Kluyveromyces marxianus YS-1 using root extract of Asparagus racemosus

Roots of Asparagus racemosus were used as a source of inulin for the production of inulinase from Kluyveromyces marxianus YS-1. Root extract prepared at 10 kg/cm² for 10 min showed the maximum production of inulinase. Various parameters of fermentation have been examined in order to improve overall enzyme yield. Inulinase yield of 40.5 IU/mL in an optimized medium containing inulin (3.5%), beef extract (0.5%), MnSO₄ (0.5 mM), CoCl₂ (0.05 mM), SDS (0.4 mM) and pH 6.5 at 30 °C under agitation (150 rpm) for 60 h has been obtained at shake flask level. After optimization the enzyme production has been increased 6.1 times at flask level. In a bioreactor (working volume 1 L) fermentation medium containing 4% inulin has shown maximum inulinase production (47.3 IU/mL) under optimized parameters of 200 rpm, 0.75 vvm aeration at 30 °C after 60 h.

Kristevan aesthetics, performativity and the production of situated knowledge

In this paper, I will draw on the work of Julia Kristeva to argue that performativity can be understood in terms of a materialist ontology that underpins creative production and the knowing subject. To understand this, we need to examine the relationship between individual history, biology and culture and processes through which creative practice attributes value by translating psychic representations of affect and drive into verbal and visual signs. Kristeva's aesthetics does not plunge us into an obscure metaphysics, but provides a model for articulating material-discursive practices that emerge from corporeal responses. Enactments, predicated by desire give rise to agency and judgement allowing practice to test theory through the production of situated knowledge.

Kristeva's psychoanalytical position reveals the necessity of linking material and individual practices of art with the social through language and interpretation. Material-discursive practices can only acquire meaning through their relationship between the speaking subject and addressees. Art itself provides us with the means for discovering the knowledge it produces. In and through material practice, the work of art is capable of transferring back to the artist as viewer, structures of meaning that have hitherto been hidden. In practice, this involves a constant movement between the biological self (the self as 'other') and the social self, the ego. In artistic research, it can be said that the first addressee is the artist her/himself, as social other. Constant movement between the two in creative practice can thus be understood as a performative production of knowledge.

Environmental art and the production of publics : responding to environmental change

Environmental crises around the world have inspired an outpour of creative response. As the effects of climate change increasingly manifest, environmental! art is being politically and pedagogically mobilised for ameliorative strategies. The rubric that instrumentalist, techno-scientific approaches to environmental stress (and attendant social distress) cannot solely provide solutions to this challenge has found increasing acceptance. The concern of this paper, however, is the limited understanding of public art's capacity that is perpetuated bv certain trends in environmental art in which the work is charged with communicative responsibility,. Connected to the representational and instructive traditions of public art, this tendency is further informed by the influence of the 'information-deficit model' in environmental conmunication research: a concept that asserts a straightforward connection between information provision, indiyidual awareness and collective action on a concern. The idea that public art can function as a conduit for knowledge,.which in turn will inspire new moral positions and behaviours, absents the art work from the process of knowledge-making and the production of conditons that enable new practice. Arguing for a revised approach to the environmental possibilities of public art, this paper will propose that in thinking aboutl environmental transformation as essentially unrepresentable, a dfferent mode of public engagement with the issue is enabled.

Rhizome / MyZone : the production of subjectivity in dance

[No Abstract]