Development of an amperometric biosensor for the detection of alcohol: a thesis presented in partial fulfilment of the requirements for the degree of Masters in Science in Biochemistry at Massey University

The aim of the following work was to design a biosensor for the detection of ethanol. A biosensor is an analytical device in which a biological sensing element is connected to or integrated with a physical transducing element. Amperometric enzyme biosensors utilise one or more enzymes to convert a substance which cannot be measured electrochemically to one which can be. In the case of an alcohol biosensor one of two enzymes (alcohol dehydrogenase and alcohol oxidase) can be used to convert electrochemically stable alcohol to either hydrogen peroxide or NADH which can be oxidised. In the design of an alcohol biosensor there are three major variables to consider, these are; enzyme type, electrode material, and immobilisation technique. The goal was to select optimum conditions for the formulation of the desired sensor. In the present work the electrode materials used were platinum, carbon (foil and paste) and the conducting organic salt N-methyl phenazinium.Tetracyanoquinodimethane (NMP.TCNQ). The immobilisation techniques used were; adsorption, cross-linking to a protein matrix and covalent binding. Of the biosensors produced from a selected combination or these variables each was tested by one or more of the following; cyclic voltammetry, enzyme assay, and amperometry. The most promising approach appears to be that of conjugating enzyme to haemin and allowing the conjugate to bind irreversibly to platinum via the haemin group. An electrode made with the organic salt NMP.TCNQ looked promising also but because the salt is readily oxidised it is unstable and therefore not an ideal electrode material

A Market-Clearing Role for Inefficiency on a Limit Order Book

Using a stochastic sequential game in ergodic equilibrium, this paper models limit order book trading dynamics. It deduces investor surplus and some agents' strategies from depth's stationarity, while bypassing altogether agents' intricate forecasting problems. Market inefficiency adjusts to induce equal supply and demand for liquidity over time. Consequently, at a given bid-ask spread surplus per investor is invariant to faster, more regular or more sophisticated trading, or modified queuing rules: apparent improvements are offset as inefficiency adjusts back to market-clearing levels. Moreover, investor surplus decreases with the spread. In the model, price discreteness fixes the spread at the tick size. Narrowing the tick is beneficial, but may be resisted by sell-side traders.stochastic sequential game, ergodic equilibrium, market microstructure, limit order book, market depths, bid-ask spread

Estimating quadratic variation when quoted prices jump by a constant increment

Financial assets' quoted prices normally change through frequent revisions, or jumps. For markets where quotes are almost always revised by the minimum price tick, this paper proposes a new estimator of Quadratic Variation which is robust to microstructure effects. It compares the number of alternations, where quotes are revised back to their previous price, to the number of other jumps. Many markets exhibit a lack of autocorrelation in their quotes' alternation pattern. Under quite general 'no leverage' assumptions, whenever this is so the proposed statistic is consistent as the intensity of jumps increases without bound. After an empirical implementation, some useful corollaries of this are given.

Cancellation and Uncertainty Aversion on Limit Order Books

This paper models limit order books where each trader is uncertain of the underlying distribution in the asset's value to others. If this uncertainty is rapidly resolved, eeting limit orders are submitted and quickly cancelled. This enhances liquidity supply, but leaves intact established comparative statics results on spreads. However, risk neutral liquidity suppliers are averse to persistent uncertainty due to concavity in the function describing limit order utility, and spreads widen. This helps explain wide spreads in the morning. The model describes traders who in equilibrium correctly anticipate market orders' endogenous stochastic intensities. It highlights how limit orders queue for execution.market microstructure, limit order book, fleeting orders, order cancellation.

Pro-rata matching and one-tick futures markets

We find and describe four futures markets where the bid-ask spread is bid down to the fixed price tick size practically all the time, and which match counterparties using a pro-rata rule. These four markets´ offered depths at the quotes on average exceed mean market order size by two orders of magnitude, and their order cancellation rates (the probability of any given offered lot being cancelled) are significantly over 96 per cent. We develop a simple theoretical model to ex- plain these facts, where strategic complementarities in the choice of limit order size cause traders to risk overtrading by submitting over-sized limit orders, most of which they expect to cancel

Standard spacecraft economic analysis. Volume 1: Executive summary

A study of the comparative program costs associated with use of various standardized spacecraft for Air Force space test program missions to be flown on the space shuttle during the 1980-1990 time period is reviewed. The first phase of the study considered a variety of procurement mixes composed of existing or programmed NASA standard spacecraft designs and a Air Force standard spacecraft design. The results were briefed to a joint NASA/Air Force audience on July 11, 1976. The second phase considered additional procurement options using an upgraded version of an existing NASA design. The results of both phases are summarized

Web Portal Design Guidelines as Identified by Children through the Processes of Design and Evaluation

The Web is an important source of information for school projects, but young users do not always find it easy to locate relevant material. A critical factor in success is the portal through which they search or browse web content. Traditionally web portals have been designed by adults with young users in mind, but there is very little evidence that the latter make use of them. In this paper design guidelines are elaborated for such portals that are based upon focus group and operational evaluations by elementary school students of two prototype web portals designed by two intergenerational teams, each comprising elementary school students and adult designers. The evaluations offer strong support for involving children throughout the design process for portals that both in presentation and functionality reflect the cognitive and affective needs of young users rather than adults