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Reliability Of Higher Seeding Rates Of Wheat For Increased Competitiveness With Weeds In Low Rainfall Environments, D Lemerle, R D. Cousens, G S. Gill, S J. Peltzer, M Moerkerk, C E. Murphy, D Collins, Brian R. Cullis Jan 2004

Reliability Of Higher Seeding Rates Of Wheat For Increased Competitiveness With Weeds In Low Rainfall Environments, D Lemerle, R D. Cousens, G S. Gill, S J. Peltzer, M Moerkerk, C E. Murphy, D Collins, Brian R. Cullis

Faculty of Engineering and Information Sciences - Papers: Part A

Increasing crop competitiveness using higher seeding rates is a possible technique for weed management in low input and organic farming systems or when herbicide resistance develops in weeds. A range of wheat seeding rates were sown and resulted in crop densities between 50–400 plants/m2 (current recommendations are 100–150 plants/m2) in the presence and absence of annual ryegrass (Lolium rigidum Gaud.) in three wheat cultivars at nine experiments in southern Australia. Wheat densities of at least 200 plants/m2 were required to suppress L. rigidum and to a lesser extent increase crop yield across a wide range …


Role Of Cr And P Additions In The Development Of Microstructure And Texture In Annealed Low Carbon Steels, E V. Pereloma, I B. Timokhina, A I. Nosenkov, J J. Jonas Jan 2004

Role Of Cr And P Additions In The Development Of Microstructure And Texture In Annealed Low Carbon Steels, E V. Pereloma, I B. Timokhina, A I. Nosenkov, J J. Jonas

Faculty of Engineering and Information Sciences - Papers: Part A

The recrystallisation behaviour of four warm rolled steels was investigated during annealing. The extra-low carbon (ELC) steel displayed the highest rate of recrystallisation, the steels with additions of chromium and phosphorus (LC(Cr)), (LC(Cr,P)) recrystallised at intermediate rates, while the interstitial-free (IF) steel exhibited the lowest rate. The additions of Cr and Cr/P increased the fraction of g-fibre in the annealing textures compared to that present in the ELC steel; this effect was particularly pronounced up to 50 % recrystallisation. After the completion of recrystallisation, the steel textures were characterized by a dominant g-fibre in the IF steel, while in the …


Delta-Ferrite Recovery Structures In Low-Carbon Steels, Rian Dippenaar, Dominic Phelan Jan 2003

Delta-Ferrite Recovery Structures In Low-Carbon Steels, Rian Dippenaar, Dominic Phelan

Faculty of Engineering and Information Sciences - Papers: Part A

The development of delta-ferrite recovery substructures in low-carbon steels has been observed in-situ utilizing laser scanning confocal microscopy (LSCM). Well-developed sub-boundaries with interfacial energies much smaller than that of delta-ferrite grain boundaries formed following transformation from austenite to delta-ferrite on heating. It is proposed that transformation stresses associated with the austenite to delta-ferrite phase transformation generate dislocations that subsequently recover into sub-boundaries by a process of polygonization. Experimental evidence in support of this proposal was found in a ferritic stainless steel. Thermal cycling through the high-temperature delta-ferrite/austenite/delta-ferrite phase transformation leads to the development of a well-defined recovery substructure, which, in …


Electrically-Small Low Q Radiator Structure And Method Of Producing Em Waves Therewith, Craig A. Grimes, Dale M. Grimes, Faton Tefiku, Gang Lui Aug 2002

Electrically-Small Low Q Radiator Structure And Method Of Producing Em Waves Therewith, Craig A. Grimes, Dale M. Grimes, Faton Tefiku, Gang Lui

Chemical and Materials Engineering Faculty Patents

An electrically small radiator structure for radiating electromagnetic waves having an electrical size, k*a, with a value less than π/2 and above π/20,000 and configured to have at least a first and second magnetic, or electric, dipole element. Dipole elements are preferably oriented such that a source-associated standing energy value for the structure, or Wds(tR), is low, Radiative Q value preferably less than (k*a)3; and each of the elements, whether paired with respective electric dipole elements, is in electrical communication through a feed circuit to at least one power source. Further, a first …


Delta-Ferrite Recovery Structures In Low Carbon Steels, Rian J. Dippenaar, Dominic J. Phelan Jan 2002

Delta-Ferrite Recovery Structures In Low Carbon Steels, Rian J. Dippenaar, Dominic J. Phelan

Faculty of Engineering - Papers (Archive)

The development of delta-ferrite recovery sub-structures in low carbon steels has been observed in-situ utlhsing laser scanniJlg confocal microscopy (LSCM). Well developed subboundaries with interfaCial' energies much smaller than that of delta-fen'ite grain boundaries fOfmed following transformation from austenite to delta-fen'ite on heating. Transfonnatioll stresses associated with the austenite to delta-fenite phase transt'onnation generate dislocations that subsequently recover into sub-boundaries by a process of polygonisation. Experimental evidence in suppol1 of this proposal was found in a ferritic stainless steel. Thermal cycling through the high temperature delta-ferrite/austenite/delta-fel1'ite phase b'ansformation leads to the development of a strong recovery substructure, wh.ich in turn. …


Experimental Investigation Of Low-Velocity Slug-Flow In A Horizontal Pipeline, David B. Hastie, Renhu Pan, Peter W. Wypych, P R Guiney Jan 2000

Experimental Investigation Of Low-Velocity Slug-Flow In A Horizontal Pipeline, David B. Hastie, Renhu Pan, Peter W. Wypych, P R Guiney

Faculty of Engineering - Papers (Archive)

An experimental program was instigated to investigate boundaries in low-velocity slug-flow pneumatic conveying. Two straight horizontal pipelines of L = 21 m were set up for actual conveying trials using two different wall materials, stainless steel and aluminium. Observations of the pneumatic conveying tests were used in determining the location of boundaries and verifying the theoretical predictions.


Low Temperature Synthesis Of Al-Aln Composites From A Nanostructure Made By Controlled Magneto-Ball Milling Of Al In Ammonia, Andrzej Calka, J I. Nikolov, G H. J Wantenaar Jan 1994

Low Temperature Synthesis Of Al-Aln Composites From A Nanostructure Made By Controlled Magneto-Ball Milling Of Al In Ammonia, Andrzej Calka, J I. Nikolov, G H. J Wantenaar

Faculty of Engineering and Information Sciences - Papers: Part A

The formation of an AlN compound in ball milled Al powder in ammonia was studied. In this work a magneto‐ball milling device with controlled ball movement was used. The end milling product was an Al based nanostructure. This product can be transformed into an AlN‐Al nanocomposite upon heating below the melting point of Al. It was found that the level of unreacted Al is dependent on milling time. The maximum amount of AlN was 88.28 wt %. The structure of as‐milled and annealed samples was investigated using x‐ray diffractometry and transmission electron microscopy. Differential thermal analysis was performed on as‐milled …


The Quantum Theory For Anomalous Low-Temperature Thermal Conductivity Of Noncrystalline Dielectric Solids, W L. Zhao, B L. Zhou Jan 1992

The Quantum Theory For Anomalous Low-Temperature Thermal Conductivity Of Noncrystalline Dielectric Solids, W L. Zhao, B L. Zhou

Faculty of Engineering - Papers (Archive)

We discuss the interaction between two-level systems and the phonon field in noncrystalline dielectric solids, and we calculate the quantum transition matrix elements ofsuch an interaction. After studying the Boltzmann equation for phonon transport. we obtain the phonon distribution function. From a direct calculation of the heat current, and as a result of obtaining the thermal conductivity of non-crystalline dielectric solids, the P relation is obtained.