ORCID Profile
0000-0002-4728-8537
Current Organisations
Flinders University
,
South Australian Museum
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Publisher: American Chemical Society (ACS)
Date: 11-1981
DOI: 10.1021/JA00413A031
Publisher: Wiley
Date: 10-1987
Publisher: SAGE Publications
Date: 11-12-2013
Abstract: This paper challenges the idea of creating an architectural approach for designing a complex hybrid cognitive agent, i.e., an agent that possesses all reactive, deliberative and affective capabilities, outside the hierarchical paradigm. Thus, it presents an agent architecture based on Marvin Minsky’s ‘Society of Mind’ (SoM) metaphor on human mind and cognition, and shows how SoM agents, through the features implicitly generated by their design, allow a tremendous power of representation of human heterogeneity and variety of behaviours. In order to show that, the SoM general architecture is instantiated and evaluated in a cognitively demanding environment: as a driver agent in a traffic behaviour context.
Publisher: Elsevier BV
Date: 06-1985
Publisher: MDPI AG
Date: 15-05-2019
DOI: 10.3390/MIN9050299
Abstract: Our examination of over 230 worldwide opal s les shows that X-ray diffraction (XRD) remains the best primary method for delineation and classification of opal-A, opal-CT and opal-C, though we found that mid-range infra-red spectroscopy provides an acceptable alternative. Raman, infra-red and nuclear magnetic resonance spectroscopy may also provide additional information to assist in classification and provenance. The corpus of results indicated that the opal-CT group covers a range of structural states and will benefit from further multi-technique analysis. At the one end are the opal-CTs that provide a simple XRD pattern (“simple” opal-CT) that includes Ethiopian play-of-colour s les, which are not opal-A. At the other end of the range are those opal-CTs that give a complex XRD pattern (“complex” opal-CT). The majority of opal-CT s les fall at this end of the range, though some show play-of-colour. Raman spectra provide some correlation. Specimens from new opal finds were examined. Those from Ethiopia, Kazakhstan, Madagascar, Peru, Tanzania and Turkey all proved to be opal-CT. Of the three specimens examined from Indonesian localities, one proved to be opal-A, while a second s le and the play-of-colour opal from West Java was a “simple” Opal-CT. Evidence for two transitional types having characteristics of opal-A and opal-CT, and “simple” opal-CT and opal-C are presented.
Publisher: Royal Society of Chemistry (RSC)
Date: 1985
DOI: 10.1039/DT9850001923
Publisher: CSIRO Publishing
Date: 1986
DOI: 10.1071/CH9861297
Abstract: The achiral green salt trans-[Co(en)2(O3SCF3) Cl ] CF3SO3 has been synthesized by controlled solvolysis of Λ- cis -or trans-[Co(en)2Cl2] Cl in CF3SO3H.Kinetic studies and proton n.m.r . and electronic absorption spectral data indicate that cis /trans isomerization of Co(en)2(O3SCF3) Cl+ in triflic acid is extremely rapid, and that the equilibrium strongly favours the trans geometry. The loss of the first Cl - from Co(en)2Cl2+ was too fast to measure (t1/2 1 s, -20°C, CF3SO3H), but the second Cl - was released at least 105-fold more slowly: k(3.5�0.1)x10-4 s-1, 25°C ΔH 73.1�1.7kJ mol-1, ΔS - 66�5 J mol-1 K-1 in the range 30-60°C. Reasons for this enormous rate difference are discussed. Solvolysis of CF3SO3- from trans- Co(en)2(O3SCF3) Cl + was immeasurably rapid in H2O, dimethyl sulfoxide (Me2SO) and dimethylformamide (Me2NCHO) (t1/2 1 s, 25°C), but it was detectable in MeCN : k 5.0×10-2 s-1, 25°C. The steric course of substitution for these solvents has been determined spectrophotometrically , and by n.m.r . spectroscopy: 0.1 M HClO4, 40.5% cis - and 59.5% trans-Co(en)2(OH2)Cl2+ Me2SO, 77% cis - and 23% trans- Co(en)2(OSMe2)Cl2+ Me2NCHO, 73% cis - and 27% trans-Co(en)2(OCHNMe2)Cl2+ MeCN , 53% cis - and 47% trans-Co(en)2(NCMe2)Cl2+ (25°C). These results are discussed in the context of a wider body of data for the stereochemistry of substitution of trans- and cis -Co(en)2ClXn+ in H2O and non-aqueous solution, where a clear leaving group dependence emerges for the trans but not the as isomers. Finally, trans- [Co(en)2(O3SCF3) Cl ] CF3SO3 provides a useful synthetic route to cis- and trans-Co(en)2ClXn+ complexes.
Publisher: Informa UK Limited
Date: 11-2006
Publisher: Wiley
Date: 1986
Publisher: CSIRO Publishing
Date: 1990
DOI: 10.1071/CH9900643
Abstract: A synthesis of [( tren )Co(μ-NH2,μ-OH)Co( tren )]4+(3)( tren = tris (2- aminoethyl )amine) is reported along with a series of derivatives: [( tren ) XCo (μ-NH2) CoX ( tren )]n+, where X = CF3SO3- (n = 3)(4), X = CH3CN (n = 5)(5), and [( tren )Co(μ-NH2,μ-CH3C(O)NH)Co( tren )]4+ (6). The substitution of (4) by CH3CN to yield (5) was studied in CH3CN at 20°C, k = 9.0×10-3 s-1, and the intramolecular hydrolysis of (5) to yield the bridging acetamide complex (6) was studied at various acid concentrations. The X-ray crystal structures were determined for (3b) (exafluorophosphate, dihydrate) and (6b) (dithionate, tetrahydrate ). Both crystals are monoclinic, respectively P21/n with a 11.082(2), b 10.402(2), c 15.611(2)Ǻ, β 99.13(2)°, Z 2, and C2/c with a 14.328(2), b 14.046(1), c 16.497(2)Ǻ, β 101.90(1)°, Z 4. For the salt of (3), 2389 data with 1 ≥ 2σ(I) were refined to R 0.070 ( Rw 0.066), and, for the salt of (6), 3087 data with I ≥ 3σ(I) were refined to R 0.041 ( Rw 0.056). Both ions lie on pseudo-symmetric sites involving disorder of the bridging ligands . The structures establish the binding mode of the acetamido ion and the orientation of the tren groups in the isolated complexes.
Publisher: Royal Society of Chemistry (RSC)
Date: 1978
DOI: 10.1039/C39780000770
Publisher: Springer Science and Business Media LLC
Date: 04-2006
Publisher: American Chemical Society (ACS)
Date: 09-1980
DOI: 10.1021/JO01308A019
Publisher: American Chemical Society (ACS)
Date: 06-1982
DOI: 10.1021/JA00375A043
Publisher: MDPI AG
Date: 07-02-2021
DOI: 10.3390/MIN11020173
Abstract: An extensive infrared (IR) spectroscopy study using transmission, specular and diffuse reflectance, and attenuated total reflection (ATR) was undertaken to characterise opal-AG, opal-AN (hyalite), opal-CT and opal-C, focussing on the Si-O fingerprint region (200–1600 cm−1). We show that IR spectroscopy is a viable alternative to X-ray powder diffraction (XRD) as a primary means of classification of opals even when minor levels of impurities are present. Variable angle specular reflectance spectroscopy shows that the three major IR bands of opal are split into transverse optical (TO) and longitudinal optical (LO) components. Previously observed variability in powder ATR is probably linked to the very high refractive index of opals at infrared wavelengths, rather than heterogeneity or particle size effects. An alternative use of ATR using unpowdered s les provides a potential means of non-destructive delineation of play of colour opals into opal-AG or opal-CT gems. We find that there are no special structural features in the infrared spectrum that differentiate opal from silica glasses. Evidence is presented that suggests silanol environments may be responsible for the structural differences between opal-AG, opal-AN and other forms of opaline silica. Complementary studies with Raman spectroscopy, XRD and scanning electron microscopy (SEM) provide evidence of structural trends within the opal-CT type.
Publisher: CSIRO Publishing
Date: 1983
DOI: 10.1071/CH9831327
Abstract: The reduction potentials of a large range of [M(NH3)5L]π+ complexes (M = CoIII, RhIII, IrIII) have been determined in aqueous solution (μ 0.1 M, NaClO4). Irreversible reductions span the range from + 0.22 to -0.47 V for cobalt(III) complexes and from -0.86 to -1.45 V for rhodium(III),and occur near -1.7 V for iridium(III), determined against the standard (KCl) calomel electrode. Despite several reports to the contrary in the literature, no correlations exist of E� with absorption spectra (Co and Rh), nuclear magnetic resonance spectra [δ(1HN), Co, Rh, Ir, and δ (59Co)], vibrational spectra [v(Co-N)], or rates of aquation and base hydrolysis (Co, Rh, Ir). Complexes which undergo outer-sphere [e.g., with Ru(NH3)62+] and predominantly inner-sphere (e.g., with VZ+aq) homogeneous electron transfer can be distinguished by the presence or absence of a correlation of In kex with E� respectively, consistent with the expectations of the Marcus-Hush theory of outer-sphere electron transfer.
Publisher: Informa UK Limited
Date: 09-10-2013
DOI: 10.1057/ORI.2013.10
Publisher: American Chemical Society (ACS)
Date: 02-1986
DOI: 10.1021/IC00224A018
Publisher: Wiley
Date: 10-1990
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/CH9920627
Abstract: Authoritative assignments have been made for the 13C and 1H nuclear magnetic resonance spectra of both essentially pure cellulose 2,3,6-trinitrate (la) and cellulose 3,6-dinitrate (1b), by using correlation spectroscopy. This study clarifies previous conflicting assignments for (1a) the revised assignment is ( ppm ): C1, 98.1 C2, 77.5 C3, 78.6 C4, 75.3 C5/C6, 70.0 in (D6) dimethyl sulfoxide . The same relative positions are retained in (D6)acetone. The study has confirmed that the product of hydroxylamine-mediated denitration is cellulose 3,6-dinitrate. Attempts to evaluate α, β γshift factors, for the change in substitution from C-ON02 to C-OH, were largely unsuccessful.
Publisher: Informa UK Limited
Date: 02-2013
DOI: 10.1057/JOS.2012.17
Publisher: Royal Society of Chemistry (RSC)
Date: 1988
DOI: 10.1039/DT9880000047
Publisher: American Chemical Society (ACS)
Date: 08-1983
DOI: 10.1021/JA00354A027
Publisher: American Chemical Society (ACS)
Date: 1989
DOI: 10.1021/IC00301A035
Publisher: Wiley
Date: 12-1989
Publisher: Elsevier BV
Date: 1987
Publisher: World Scientific Pub Co Pte Lt
Date: 12-2004
DOI: 10.1142/S0217595904000345
Abstract: Conceptual models are the critical first step to gaining distilled insights of complex systems. We use influence diagrams to link intuitive measures for Land Force actions with the inputs of the environment, and friendly and threat force actions. This approach provides a rich semiquantitative model that allows exploration of the effect of perturbation introduced through the adoption of enhanced equipment, innovative operational concepts, or novel technology concepts. We have built a construct for the Army based upon a set of influence diagrams for the skills of: engagement information collection sustainment communication protection movement and decision making. These produce mental maps that link military technologies, desired effects, and higher-level outcomes. Thus, there is a gradation of type within the influence diagram with position the key to the nature of the variable. In this paper we describe these models and how we use them to deduce likely future military concepts through "what if" contemplations of possible technology or environmental changes. In reverse, this process advises on the criticality of the constituent components. Inter-relationships between various skills and issues associated with balancing requirements between these will be highlighted. This work thus leads to further distillation-like simulations such as agent-based modeling.
Publisher: Elsevier BV
Date: 12-2006
DOI: 10.1016/J.YMGME.2006.06.009
Abstract: Carnitine-acylcarnitine translocase (CACT) deficiency is a rare disorder of fatty acid oxidation associated with high mortality. Two female newborns of different ethnic origin (the first Anglo-Celtic and the second Palestinian Arab) both died after sudden collapse on day 2 of life. Both had elevated bloodspot long-chain acylcarnitines consistent with either CACT or carnitine palmitoyltransferase II (CPT2) deficiency the latter was excluded by demonstrating normal CPT2 activity in fibroblasts. Direct sequencing of all SLC25A20 (CACT) gene exons and exon-intron boundaries revealed that Patient 1 was compound heterozygous for a novel c.609-3c>g (IVS6-3c>g) mutation on the paternal allele and a previously described c.326delG mutation on the maternal allele. Patient 2 was homozygous for the same, novel c.609-3c>g mutation. Previously reported SLC25A20 mutations have been almost exclusively confined to a single family or ethnic group. Analysis of fibroblast cDNA by RT-PCR, agarose gel electrophoresis and sequencing of extracted bands showed that both mutations produce aberrant splicing. c.609-3C>G results in exon 7 skipping leading to a frameshift with premature termination seven amino acids downstream. c.326delG was confirmed to produce skipping of exons 3 or 3 plus 4. CACT activity in both patients' fibroblasts was near-zero. For both families, prenatal diagnosis of an unaffected fetus was performed by mutation analysis on CVS tissue in a subsequent pregnancy. Due to the urgency of prenatal diagnosis in the second family, molecular diagnosis was performed prior to demonstration of CACT enzyme deficiency, illustrating that mutation analysis is a rapid and reliable approach to first-line diagnosis of CACT deficiency.
Publisher: American Chemical Society (ACS)
Date: 06-1980
DOI: 10.1021/JA00533A024
Publisher: Canadian Science Publishing
Date: 1981
DOI: 10.1139/V81-012
Abstract: Several compounds of the title class have been synthesized as small-molecule analogues for the metal-binding sites in such biochemical systems as ADH. The ligands containing pyridine and two thioethers do not bind alent metals (Co 2+ , Zn 2+ , Cu 2+ , Ni 2+ ), strongly suggesting that thioethers are poorly chelated. However, the analogues containing free SH groups bind alent metals very strongly, producing complexes with limited solubility at pH values in excess of 6. Titration of the latter ligands in the presence of 1 equiv. Zn 2+ indicates the consumption of 3 equiv. OH − by pH 6, one for the [Formula: see text] ionization, and one for each S—H bound to Zn 2+ . On the basis of these data the resulting complexes are considered to neutral bis-thiolates. The relationship of these data to the state of ionization of the Zn 2+ -cysteine SH's in ADH is discussed.
Publisher: Informa UK Limited
Date: 08-2006
Publisher: Elsevier BV
Date: 05-2016
Publisher: Elsevier BV
Date: 10-2012
Publisher: CSIRO Publishing
Date: 1983
DOI: 10.1071/CH9831495
Abstract: The complexes Cr(NH3)5L3+ [L = OCHNH2, OC(NH2)2 and OC(NHMe)2] have been synthesized as the O-bound isomers. At 25�C in aqueous base (pH c. 10-14) they isomerize to the deprotonated N-bound isomers without competitive hydrolysis. Reacidification regenerates the O-bound isomer rapidly and completely. The second-order rate constants and pKa values of the amide complexes (I 1.0 M, 25�C) are respectively: 37.0 � 1.5 dm3 mol-1 s-1 and 11.72 � 0.06 for formamide 0.324 � 0.004 dm3 mol-1 s-1 and l3.50 � 0.05 for urea 0.0375 � 0.0020 dm3 mol-1 s-1 and 14.0 � 0.2 for N,N'-dimethylurea. The observations for chromium(III) parallel similar behaviour in cobalt(III) and rhodium(III) analogues, but are unusual for chromium(III) chemistry.
Publisher: American Chemical Society (ACS)
Date: 02-1984
DOI: 10.1021/JA00315A029
Publisher: Informa UK Limited
Date: 09-2011
Publisher: MDPI AG
Date: 04-03-2022
DOI: 10.3390/MIN12030323
Abstract: Single pulse, solid-state 29Si nuclear magnetic resonance (NMR) spectroscopy offers an additional method of characterisation of opal-A and opal-CT through spin-lattice (T1) relaxometry. Opal T1 relaxation is characterised by stretched exponential (Weibull) function represented by scale (speed of relaxation) and shape (form of the curve) parameters. Relaxation is at least an order of magnitude faster than for silica glass and quartz, with Q3 (silanol) usually faster than Q4 (fully substituted silicates). 95% relaxation (Q4) is achieved for some Australian seam opals after 50 s though other s les of opal-AG may take 4000 s, while some figures for opal-AN are over 10,000 s. Enhancement is probably mostly due to the presence of water/silanol though the presence of paramagnetic metal ions and molecular motion may also contribute. Shape factors for opal-AG (0.5) and opal-AN (0.7) are significantly different, consistent with varying water and silanol environments, possibly reflecting differences in formation conditions. Opal-CT s les show a trend of shape factors from 0.45 to 0.75 correlated to relaxation rate. Peak position, scale and shape parameter, and Q3 to Q4 ratios offer further differentiating feature to separate opal-AG and opal-AN from other forms of opaline silica. T1 relaxation measurement may have a role for provenance verification. In addition, definitively determined Q3/Q4 ratios are in the range 0.1 to 0.4 for opal-AG but considerably lower for opal-AN and opal-CT.
Publisher: Royal Society of Chemistry (RSC)
Date: 1984
DOI: 10.1039/C39840001571
Publisher: CSIRO Publishing
Date: 1988
DOI: 10.1071/CH9880585
Abstract: A procedure has been developed for the N- ethylation and methylation of 1,3-diphenylureas, ArNRCONHAr′ (R = H, Me or Et), through treatment with sodium hydride and iodoalkane in dimethylformamide. The reaction was general, provided that the aniline to be alkylated was substituted with no more than one nitro group. ArRNCONR′Ar′ derivatives prepared were: R = R′ = Et (and Me) Ar = phenyl, Ar′ = 2-nitrophenyl and 4- nitrophenyl Ar = 2-nitrophenyl, Ar′ = 2-nitrophenyl and 4-nitrophenyl Ar = Ar′ = 4-nitrophenyl. Two mixed derivatives were also prepared: R = Et, R′ = Me, Ar = phenyl, Ar′ = 2-nitrophenyl and 4-nitrophenyl. O-Alkylated isourea products were obtained in the reactions of 1-(2,4- dinitrophenyl )-3-(2-nitrophenyl)urea and 1-(2,4-dinitrophenyl)-3-(4- nitrophenyl )urea. The use of potassium carbonate as the base led to apparently exclusive O- alkylation of 1,3-bis(2-nitrophenyl)urea although the reaction was not general. 1-(2,4-Dinitrophenyl)-1,3- diethyl-3-phenylurea was prepared by using silver oxide and obtained as a mixture with the isourea . Many of the compounds prepared are important nitro derivatives of the propellant stabilizers, ethyl and methyl centralite.
Publisher: Elsevier BV
Date: 12-2014
Publisher: American Chemical Society (ACS)
Date: 03-1986
DOI: 10.1021/IC00227A030
Publisher: Royal Society of Chemistry (RSC)
Date: 1977
DOI: 10.1039/C39770000725
Publisher: Danish Chemical Society
Date: 1987
Publisher: World Scientific Pub Co Pte Lt
Date: 06-2011
DOI: 10.1142/S1469026811003045
Abstract: A lip-reading technique that identifies visemes from visual data only and without evaluating the corresponding acoustic signals is presented. The technique is based on vertical components of the optical flow (OF) analysis and these are classified using support vector machines (SVM). The OF is decomposed into multiple non-overlapping fixed scale blocks and statistical features of each block are computed for successive video frames of an utterance. This technique performs automatic temporal segmentation (i.e., determining the start and the end of an utterance) of the utterances, achieved by pair-wise pixel comparison method, which evaluates the differences in intensity of corresponding pixels in two successive frames. The experiments were conducted on a database of 14 visemes taken from seven subjects and the accuracy tested using five and ten fold cross validation for binary and multiclass SVM respectively to determine the impact of subject variations. Unlike other systems in the literature, the results indicate that the proposed method is more robust to inter-subject variations with high sensitivity and specificity for 12 out of 14 visemes. Potential applications of such a system include human computer interface (HCI) for mobility-impaired users, lip reading mobile phones, in-vehicle systems, and improvement of speech based computer control in noisy environment.
Location: Australia
Location: Australia
Location: No location found
No related grants have been discovered for Neville J Curtis.