Oral History Interview with John Niland: Conceptualising SMU

This is an abridged version of the original interview. Please contact the Library at [email protected] for access to the full version of the transcript and/or audio recording.</p

Critical studies in carbon electrode materials with applications in the electroanalysis of the mycotoxin citrinin

Guided by increasing legislation, the analysis of food borne toxins, including mycotoxins, seeks to address market related demands for the development of analytical systems to monitor this threat to food security and human health. This Thesis is directed at the assessment of the application of electrochemistry for direct electroanalysis and characterisation of the mycotoxin citrinin (CIT) in aqueous media as well as fundamental investigations of the surface of polished and oxidised glassy carbon electrodes (GCE). This study provides the first known account of CIT detection through electrochemical methods. Although electrochemically active, CIT current responses (Ip) were highly irreproducible at polished GCE with a coefficient of variation (C.V.) of 20.16 %. As stability of Ip across multiple electrode preparations is a key requirement in electroanalysis, investigations were directed at attaining stability in CIT Ip. Achieving stability in CIT Ip was investigated via two approaches, including: accounting for Ip variability between electrode preparations as a result of variable GCE surface conditions as a post-data-acquisition analysis and secondly, removing Ip variability through modification of GCE. Accounting for variability in Ip was investigated through the application of double layer capacitance as an indicator of the activity of an electrode, and in so doing serving as a relative mediator of Ip responses between electrodes. Application of this procedure dropped CIT C.V. to a third of starting value across polished GCE (C.V. = 7.18 %), chemically oxidised GCE (Pi-GCE, C.V = 8.47 %) and functionalised multi-walled carbon nanotube modified GCE (fMWCNT, C.V. = 25.79 %) and was effective with analysis of structurally distinct molecules, 2,4-dimethylaniline (2,4-DMA) and 1,2,4-trihydroxybenzene (Triol). Furthermore, it afforded the ability to determine discreet solution overlapping data sets of Ip. Stabilising Ip through GCE surface modification was achieved by anodic electro-oxidation of GCE and allowed for direct electroanalysis of CIT and subsequent characterisation and analysis of CIT in complex media as it reduced C.V. of CIT Ip to 0.73 %. Fundamental investigations of the electrode surface condition are described such that the source of variability could be identified and the interactions of CIT with the electrode understood. Two surface oxidation techniques were applied in modification of GCE; anodic electro-oxidation (EOx GCE) and chemical oxidation using piranha solution (Pi-GCE), analysis of which has previously not been reported. Fundamental analyses to determine surface morphology and chemistry of Pi-GCE, EOx-GCE and polished GCE were conducted using high resolution scanning electron microscopy (HRSEM), scanning electrochemical microscopy (SECM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FTIR) and via electroanalytical methods. These studies showed that both oxidation procedures introduced a variety of oxide species at GCE surface, and further that the extent of those species was similar with total % O being 27.67 % and 33.47 % at Pi-GCE and EOx-GCE respectively. Although chemically similar, each surface was morphologically distinct. Electrochemical analyses at the surfaces revealed Pi-GCE to behave more similarly to polished GCE than EOx-GCE. As CIT responses were found to be stable at EOx-GCE (C.V. = 0.73 %) as opposed to Pi-GCE (C.V. = 22.87 %), stability of CIT Ip was likely to be as a result of a physical interaction with electrode morphology rather than interaction on a chemical basis. Morphological analyses revealed polished GCE and Pi-GCE to be highly morphologically irregular at the micro-scale. Although comparatively smooth, the surface morphology of EOx-GCE does not account for the stability of Ip. This study thus proposed a theory to describe the mechanism by which the limited conductivity and porosity of EOx-GCE allow for it to provide a relatively stable surface area within the oxide layer, adjacent to the electrode surface, and thus provided a stable platform for electroanalysis. Voltammetric characterization of CIT at EOx-GCE revealed that anodic oxidation in aqueous media involved an uneven number of electrons to protons via an ECE mechanism. This was illustrated to be nt = 2e- accompanied by the transfer of 1H⁺ per molecule oxidised. A proposed reaction scheme for the initial stages of CIT oxidation was suggested to involve both hydroxyl and carboxyl moieties of the CIT molecule. CIT oxidation was shown to arise as a result of a relatively complex mass transport regime which included both adsorptive and diffusive derived Ip₁. The LOD in buffered aqueous media was found to be 16 nM, a highly competitive result in relation to chromatographic techniques. Further application of EOx-GCE in complex media illustrated that CIT associates non-specifically with the components of food samples, primarily proteins. As a result of this, extraction of CIT from such media is mandatory. Liquid-liquid extraction illustrated a recovery in CIT Ip₁ and in so doing provided a means of accurately and sensitively detecting CIT from food samples with an LOD of 20 nM. These responses were corroborated by HPLC analyses on the same extractions and illustrate the applicability of electroanalysis as an analytical technique

Texas Law\u27s Life or Death Rule in Capital Sentencing: Scrutinizing Eight Amendment Violations and the Case of Juan Guerrero, Jr.

The United States Supreme Court has never explained the Eighth Amendment’s impact in noncapital cases involving a mentally retarded or brain-injured defendant. The Court has not provided guidance to legislatures or lower courts concerning the acceptable balancing of aggravating and mitigating factors and the role that mitigating factors must play in the sentencing decision. A definitive gap exists between the protections afforded to a criminal defendant facing a life sentence as opposed to those confronted with the death penalty. The Court requires sentencing procedures to consider aggravating and mitigating factors, including mental retardation and brain damage, when imposing a death sentence. The sentencing procedures, however, have no such requirement for a life sentence. The Court has held that death is too excessive a punishment if an inmate is mentally retarded. Nevertheless, the Court must evaluate whether the non-consideration of either mental retardation or brain injury in noncapital cases complies with the Eighth Amendment. The legal community does not know with certainty what the acceptable degree of proportionality might be in life imprisonment cases. In Texas, if the death penalty has been ruled out, Texas’s statutory scheme gives no consideration to a defendant’s right to have a jury consider the mitigating circumstances of their history for life imprisonment sentences. Such an omission runs afoul of Supreme Court precedents in death penalty cases. The existence of these mitigating factors should warrant the sentencing authority the ability to consider them before handing down a life sentence. No present authority exists as to whether complete uniformity is constitutionally permissible for life sentences. Similarly, Texas courts have never held that automatic life sentences violate the Eighth Amendment. Therefore, the Court must articulate the proper degree of scrutiny necessary when evaluating the constitutionality of the Eighth Amendment to life sentences

Texas Law\u27s Life or Death Rule in Capital Sentencing: Scrutinizing Eight Amendment Violations and the Case of Juan Guerrero, Jr.

The United States Supreme Court has never explained the Eighth Amendment’s impact in noncapital cases involving a mentally retarded or brain-injured defendant. The Court has not provided guidance to legislatures or lower courts concerning the acceptable balancing of aggravating and mitigating factors and the role that mitigating factors must play in the sentencing decision. A definitive gap exists between the protections afforded to a criminal defendant facing a life sentence as opposed to those confronted with the death penalty. The Court requires sentencing procedures to consider aggravating and mitigating factors, including mental retardation and brain damage, when imposing a death sentence. The sentencing procedures, however, have no such requirement for a life sentence. The Court has held that death is too excessive a punishment if an inmate is mentally retarded. Nevertheless, the Court must evaluate whether the non-consideration of either mental retardation or brain injury in noncapital cases complies with the Eighth Amendment. The legal community does not know with certainty what the acceptable degree of proportionality might be in life imprisonment cases. In Texas, if the death penalty has been ruled out, Texas’s statutory scheme gives no consideration to a defendant’s right to have a jury consider the mitigating circumstances of their history for life imprisonment sentences. Such an omission runs afoul of Supreme Court precedents in death penalty cases. The existence of these mitigating factors should warrant the sentencing authority the ability to consider them before handing down a life sentence. No present authority exists as to whether complete uniformity is constitutionally permissible for life sentences. Similarly, Texas courts have never held that automatic life sentences violate the Eighth Amendment. Therefore, the Court must articulate the proper degree of scrutiny necessary when evaluating the constitutionality of the Eighth Amendment to life sentences

Toward the influence of the organisation on big data analytics

Big Data Analytics (BDA) capabilities are of significant interest to organisations as they are reportedly able to enhance Firm Performance (FPer). This is or particular interest given the ever increasing demands on business to remain competitive within a dynamic market. Though BDA has been shown to be effective across diverse industries and applications, it has also been shown to be ineffective in many occasions. This study draws on theories concerning organisational capabilities, including dynamic capability theory, decision making theory and organisational culture theory to assess the influence of the organisation on the effectiveness of a BDA capability. In so doing, this study extends the above research streams by assessing the direct and moderated influences of Firm Dynamic Capability (FDC), Organisational Culture to BDA (OCDA) and Data Driven Decision Making (DDDM) on the BDA capability, and the resulting impact on FPer. The hierarchical research model was assessed with 80 online survey responses from respondents primarily based in South Africa who were directly associated with a BDA capability in their organisation. The results illustrate the significant direct and moderating impact of on BDA and FPer. The implications of these findings are discussed relative to both theoretical and practical applications in business settings, followed by considerations for further research required in the field.Mini Dissertation (MBA)--University of Pretoria, 2017.km2018Gordon Institute of Business Science (GIBS)MBAUnrestricte

A new method for x-ray fluorescence analysis of contaminated material. Final Report

Niton has successfully completed the objectives of the Phase II program to build a hand-held, x-ray fluorescent analyzer optimized for DOE decontamination and decommissioning activities in the field. A two-pound x-ray fluorescence analyzer was developed that contains 3 radioactive sources, emitting 3 widely spaced monochromatic x-rays, to give the lowest detection limits for the full range of toxic elements, from chromium to plutonium. A rapid, fundamental- parameters algorithm was developed that yields quantitative results in less than 1 second. High-resolution silicon drift detectors and silicon PIN diodes give excellent efficiency and speed. These results from Phase II have been introduced into the XL 300, 700 and 800 commercial products series. More than 800 of these instruments, yielding revenues of more than $20 million dollars, have been sold since the first 3-source instrument was introduced in 1998. A direct consequence of the Phase II funding has been the growth of Niton from 20 people to its present size of 60

The Brain Drain of Highly Trained Engineering Manpower From Asia Into Theunited States

195 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1970.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Recent trends in industrial relations and human resource policies and practices: the Australian experience

Dissertação de Mestrado em Física, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra.The aim of this Thesis is to study the e ect of an Event Horizon on the entanglement of the Quantum Vacuum and how entanglement, together with the Holographic Principle, may explain the current value of the Cosmological Constant, in light of recent theories. Entanglement is tested for vacuum states very near and very far from the Horizon of a de Sitter Universe, using the Peres-Horodecki (PPT) criterion. The states are averaged inside two boxes of volume V so that they acquire the structure of a bipartite Quantum Harmonic Oscillator, for which the PPT criterion is a necessary but not su cient condition of separability. The rst chapters are an introduction to: the Quantum Vacuum and its physical manifestation, quantum entanglement and its application to Gaussian States and Quantum Harmonic Oscillators, the Holographic Principle, the relation between entanglement and the Holographic Principle, theories developed to calculate the Cosmological Constant, and the experimental methods used to measure it. Entanglement was found between states averaged inside spherical shells with thickness of the order of one Planck distance (lp), when one of the states is near the Horizon, and the other state is anywhere in the Universe. Entanglement disappears when the distance of the state near the horizon and the Horizon increases to a value somewhere between 10lp and 60lp, or, in other words, when the state is at distances larger than O(10lp) to the Horizon. If we consider the Horizon not as a surface but as a spherical shell of thickness lp, then this means that there is entanglement between the states in the Horizon and the rest of the Universe. When both states are at distances larger than 60lp from the Horizon, no entanglement was found