13 resultados para Chemistry, Analytical|Sociology, Criminology and Penology

em Deakin Research Online - Australia


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The main challenges in the manufacture of composite materials are low surface energy and the presence of silicon-containing contaminants, both of which greatly reduce surface adhesive strength. In this study, carbon fiber (CF) and E-glass epoxy resin composites were surface treated with the Accelerated Thermo-molecular adhesion Process (ATmaP). ATmaP is a multiaction surface treatment process where tailored nitrogen and oxygen functionalities are generated on the surface of the sample through the vaporization and atomization of n-methylpyrrolidone solution, injected via specially designed flame-treatment equipment. The treated surfaces of the polymer composites were analyzed using XPS, time of flight secondary ion mass spectrometry (ToF-SIMS), contact angle (CA) analysis and direct adhesion measurements. ATmaP treatment increased the surface concentration of polar functional groups while reducing surface contamination, resulting in increased adhesion strength. XPS and ToF-SIMS showed a significant decrease in silicon-containing species on the surface after ATmaP treatment. E-glass composite showed higher adhesion strength than CF composite, correlating with higher surface energy, higher concentrations of nitrogen and CO functional groups (from XPS) and higher concentrations of oxygen and nitrogen-containing functional groups (particularly C2H3O+ and C2H5NO+ molecular ions, from ToF-SIMS).

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This paper presents a comprehensive analytical subdomain model together with its field solutions for predicting the magnetic field distributions in surface-mounted permanent magnet (PM) machines. The tooth tips and slotting effects during open-circuit, armature reaction, and on-load conditions are considered when deriving the model and developing its solutions. The model derivations and field solutions are extended from a previous model, and can be applied to PM machines with any combinations of slot and pole numbers and any magnetization patterns in the magnets. This model is initially formulated according to Laplace's and Poisson's equations in 2-D polar coordinates by the separation of variables technique in four subdomains, such as magnet, airgap, winding slots, and slot-openings. The field solution of each subdomain is obtained applying the appropriate boundary conditions and interface conditions between every two subdomains, respectively, which can precisely account for the mutual influence between slots. Finite element analysis (FEA) is later deployed to validate the analytical results in a surface-mounted PM machine that has nonoverlapping winding arrangement. For validation purposes, PM machines having 3-slot/2-pole with parallel magnetization and 12-slot/10-pole with either parallel or radial magnetizations are used for comparisons. Computation of global quantities for the motor which include the phase back-EMF and cogging torque is also included. The results indicate that the proposed analytical model can accurately predict the magnetic field distributions in each subdomain and the motor's global quantities, which are in good agreement with those obtained from the FEA.

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Laser ablation of selected coordination complexes can lead to the production of metal-carbon hybrid materials, whose composition and structure can be tailored by suitably choosing the chemical composition of the irradiated targets. This 'laser chemistry' approach, initially applied by our group to the synthesis of P-containing nanostructured carbon foams (NCFs) from triphenylphosphine-based Au and Cu compounds, is broadened in this study to the production of other metal-NCFs and P-free NCFs. Thus, our results show that P-free coordination compounds and commercial organic precursors can act as efficient carbon source for the growth of NCFs. Physicochemical characterization reveals that NCFs are low-density mesoporous materials with relatively low specific surface areas and thermally stable in air up to around 600°C. Moreover, NCFs disperse well in a variety of solvents and can be successfully chemically processed to enable their handling and provide NCF-containing biocomposite fibers by a wet-chemical spinning process. These promising results may open new and interesting avenues toward the use of NCFs for technological applications.

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Despite a growing acceptance of the value of evolutionary approaches to understanding the natural world there has been relatively little attention paid to evolutionary ideas in sociology, socio-cultural anthropology, and — of particular relevance for this special issue — criminology and forensic/correctional psychology. The aim of this paper is to provide an introductory overview of evolutionary approaches to human behavior with a focus on illuminating the role they can play in enriching our understanding of criminal and antisocial behavior. We begin with an overview of the main approaches to applying evolutionary theory to human behavior and we suggest that a pluralistic perspective is most likely to advance conceptual and empirical work in the field. We then turn to a brief discussion of some common, but misguided criticisms of this approach. Some of the more substantive conceptual and methodological issues that evolutionary approaches need to address are then explored. Finally, we engage with the broader issues that relate to the role of evolutionary explanations in the social and behavioral sciences.

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Law reform is increasingly underpinned by empirical research. This is clearly evident in contemporary reform of the laws of self-defence and homicide. These reforms have been motivated largely by concern for battered women who kill their abusive partners. An extensive body of empirical criminological research has been utilised to identify bias in the operation of the traditional law of homicide and self-defence and has been relied upon by many law reform bodies. This article identifies and evaluates the "implicit criminology" constituted by these empirical studies. Five matters that have formed the backdrop to contemporary reform are investigated: the origins of the law of murder; the operation of the law of self-defence; the historical utilisation of mental state defences by battered women; the circumstances in which battered women kill their abusers; and the trial as a key location for processing these offenders. It is argued that the implicit criminology that has driven reform of the law of homicide and self-defence is largely undeveloped or unsubstantiated. Despite the centrality of concern for battered defendants in much contemporary discussion in criminology and the criminal law, it appears that there is still substantial research to be done to clarify the circumstances in which victims of chronic violence kill their abusive partners, how these defendants experience the law and the availability of self-defence to them. What seems to have been established may be more complex, contingent and inchoate than previously acknowledged.

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My doctoral research studies Australian PLT practitioners’ engagement with scholarship of teaching and learning. I argue that many PLT practitioners are motivated to engage with scholarship of teaching and learning in their work. There are, however, individual and extra-individual impediments.
PLT practitioners are lawyers that teach in institutional practical legal training (“PLT”). Satisfactory completion of mandatory PLT is an eligibility requirement for admission to the Australian legal profession. The PLT requirement is additional to academic legal qualifications. PLT is undertaken at a post-graduate level with, or after, the academic law degree.
My study investigates PLT practitioners’ motivations and capabilities to engage with scholarship of teaching and learning (“SoTL”). I study organisational symbolic support for SoTL in PLT, and organisational allocation of resources to SoTL in PLT.
The study involves individual and extra-individual domains of PLT practitioners’ work. It considers how social structures (e.g. “the juridical”) are inscribed into individuals’ practices (“teaching”) and, conversely, whether practices influence social structures.
My research adopts qualitative methodologies. These involve inter-disciplinary exchanges between law, legal education, practice research, sociology of law, cultural theory, and theory and practice of teaching and learning. My theoretical framework draws on Pierre Bourdieu’s “reflexive sociology”, and Michel de Certeau’s “heterological science”.
I sourced data from documents, and semi-structured interviews with 36 Australian PLT practitioners. Documentary sources include statutory instruments, speeches, reports, practice directions, histories, and scholarly publications.
To analyse the data I adopted Kelle’s characterisation of “theoretical sensitivity”, drawing on “explicit” and “emergent” analysis strategies derived from “grounded theory”. The explicit strategies were based on my theoretical framework. The emergent strategy involved sensitivity to non-explicit concepts and theories that emerged from the data. Computer-aided qualitative data analysis software expedited these methods.
My findings to date question dominant legal structures’ readiness for change, the implications of this for teaching and learning in PLT, and in particular for PLT practitioners’ engagement with SoTL in PLT.
The espoused rationale for mandatory PLT (in statutes) is improvement for the protection of clients, the administration of justice, and to assure quality legal services. The tacit rationale is improved quality of legal education, and experiences, for lawyers-to-be. My thesis argues dominant structures in legal education impede the espoused and tacit objectives, and impede PLT practitioners’ engagement with scholarship of teaching and learning.

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The increase in polyunsaturated fatty acid (PUFA) consumption has prompted research into alternative resources other than fish oil. In this study, a new approach based on focal-plane-array Fourier transform infrared (FPA-FTIR) microspectroscopy and multivariate data analysis was developed for the characterisation of some marine microorganisms. Cell and lipid compositions in lipid-rich marine yeasts collected from the Australian coast were characterised in comparison to a commercially available PUFA-producing marine fungoid protist, thraustochytrid. Multivariate classification methods provided good discriminative accuracy evidenced from (i) separation of the yeasts from thraustochytrids and distinct spectral clusters among the yeasts that conformed well to their biological identities, and (ii) correct classification of yeasts from a totally independent set using cross-validation testing. The findings further indicated additional capability of the developed FPA-FTIR methodology, when combined with partial least squares regression (PLSR) analysis, for rapid monitoring of lipid production in one of the yeasts during the growth period, which was achieved at a high accuracy compared to the results obtained from the traditional lipid analysis based on gas chromatography. The developed FTIR-based approach when coupled to programmable withdrawal devices and a cytocentrifugation module would have strong potential as a novel online monitoring technology suited for bioprocessing applications and large-scale production.

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Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines.

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Acidic potassium permanganate chemiluminescence enables direct post-column detection of glutathione, but its application to assess the redox state of a wider range of biological fluids and tissues is limited by its sensitivity. Herein we show that the simple on-line addition of an aqueous formaldehyde solution not only enhances the sensitivity of the procedure by two orders of magnitude, but also provides a remarkable improvement in the selectivity of the reagent towards thiols such as glutathione (compared to phenols and amino acids that do not possess a thiol group). This enhanced mode of detection was applied to the determination of glutathione and its corresponding disulfide species in homogenised striatum samples taken from both wild type mice and the R6/1 transgenic mouse model of Huntington's disease, at both 8 and 12 weeks of age. No significant difference was observed between the GSH/GSSG ratios of wild type mice and R6/1 mice at either age group, suggesting that the early disease progression had not significantly altered the intracellular redox environment.

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Environmental context Soils contaminated with metals can pose both environmental and human health risks. This study showed that a common crop vegetable grown in the presence of cadmium and zinc readily accumulated these metals, and thus could be a source of toxicity when eaten. The work highlights potential health risks from consuming crops grown on contaminated soils. Abstract Ingestion of plants grown in heavy metal contaminated soils can cause toxicity because of metal accumulation. We compared Cd and Zn levels in Brassica rapa, a widely grown crop vegetable, with that of the hyperaccumulator Solanum nigrum L. Solanum nigrum contained 4 times more Zn and 12 times more Cd than B. rapa, relative to dry mass. In S. nigrum Cd and Zn preferentially accumulated in the roots whereas in B. rapa Cd and Zn were concentrated more in the shoots than in the roots. The different distribution of Cd and Zn in B. rapa and S. nigrum suggests the presence of distinct metal uptake mechanisms. We correlated plant metal content with the expression of a conserved putative natural resistance-associated macrophage protein (NRAMP) metal transporter in both plants. Treatment of both plants with either Cd or Zn increased expression of the NRAMP, with expression levels being higher in the roots than in the shoots. These findings provide insights into the molecular mechanisms of heavy metal processing by S. nigrum L. and the crop vegetable B. rapa that could assist in application of these plants for phytoremediation. These investigations also highlight potential health risks associated with the consumption of crops grown on contaminated soils.

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A series of norbornane containing amphiphiles was synthesized, their lipophilicity corresponding to neutral and cationic forms was then investigated using reverse phase HPLC (High Performance Liquid Chromatography). This series of amphiphiles incorporated varied lipophilic chain length and also varied distances between the polar/cationic head group from the norbornane scaffold. Our investigation included studying the impact of the stationary phase as a replication of a membrane for both cationic and neutral amphiphiles. The choice of stationary phase was shown to be a very important consideration for this type of measurement. In this connection, C18, Cyano and Polar columns were all investigated, the cyano column was observed to be the optimal stationary phase for the comparison of both charged and neutral amphiphiles.

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A series of aliphatic tertiary amines (HEPES, POPSO, EPPS and BIS-TRIS) commonly used to buffer the pH in biological experiments, were examined as alternative, non-toxic co-reactants for the electrogenerated chemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(ii) ([Ru(bpy)3](2+)). These were found to be very attractive as "multi-tasking" reagents, serving not only as co-reactants, but also fulfiling the roles of pH buffer and supporting electrolyte within an aqueous environment; thus significantly simplifying the overall ECL analysis. Sub-nanomolar detection limits were obtained for [Ru(bpy)3](2+) in the presence of BIS-TRIS, making this species an valuable option for co-reactant ECL-based bioanalytical applications.

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Decomposition of poly(vinyl alcohol)/montmorillonite clay (PVA/MMT) composites during melting-crystallization was experimentally confirmed by morphology and molecular structure changes. In particular, FTIR spectra show the shift of O-H stretching band as well as enhanced intensities of C-O stretching and CH2 rocking vibrational modes. Furthermore, Raman deconvolution indicates that C-H wagging, CH2-CH wagging, CH-CO bending and CH2 wagging modes in amorphous domains were all decreased greatly. Moreover, this decomposition leads to decreased melting enthalpy, melting point, crystallization enthalpy and crystallization temperature. Crystallization analysis shows that the MMT incorporated slows down the crystallization process in the PVA matrix regardless of the nucleation capability of MMT. Despite the severe decomposition, the crystallization kinetics still corroborated well with common classical models. As a result, molecular structure changes and crystallization retardation observed in this study clearly indicate the strong effects of the thermal degradation on the non-isothermal crystallization of PVA/MMT composites.