Collective electrodynamics I

Standard results of electromagnetic theory are derived from the direct interaction of macroscopic quantum systems; the only assumptions used are the Einstein-deBroglie relations, the discrete nature of charge, the Green's function for the vector potential, and the continuity of the wave function. No reference is needed to Maxwell's equations or to traditional quantum formalism. Correspondence limits based on classical mechanics are shown to be inappropriate

A silicon model of auditory localization

The barn owl accurately localizes sounds in the azimuthal plane, using interaural time difference as a cue. The time-coding pathway in the owl's brainstem encodes a neural map of azimuth, by processing interaural timing information. We have built a silicon model of the time-coding pathway of the owl. The integrated circuit models the structure as well as the function of the pathway; most subcircuits in the chip have an anatomical correlate. The chip computes all outputs in real time, using analog, continuous-time processing

Surviving Alpha: Using sequential analysis to examine the behaviours of Black-legged Kittiwake chicks during sibling pecking attacks

Kittiwake chicks engage in pecking attacks against their siblings, which can result in brood reduction by facultative siblicide. Attacks are almost exclusively carried out by Alpha (first-hatched) chicks against Beta (second-hatched) chicks. Onset of this behaviour is attributable to food stress brought about by environmental conditions which impact parental foraging success within breeding seasons. Size differences between siblings, due to asynchronous hatching, allow alpha chicks to dominate parental feeds and pecking attacks primarily occur during feeding events in response to beta attempts to gain food from parents. Yet attacks have been observed outside of feeding events and beta chicks can survive to fledging, even delivering retaliatory attacks in some instances. The responses of beta chicks during attacks were examined by Cullen (1957) whereby beak hiding motions by beta chicks such as facing away or tucking in the beak served as appeasement strategies and these were discussed as adaptations to Kittiwakes’ habit of cliff nesting. Use of appeasement by beta chicks suggests that, notwithstanding the environmental and hierarchical factors, beta chicks have some agency in their survival through their behavioural responses to alpha siblings. In this thesis, I use sequential analysis to examine in concatenation, the behavioural sequences of alpha and beta chicks, with particular attention to those immediately preceding and following pecking attacks. In this way I hope to better understand the inter-relationship of alpha and beta chick behaviours during pecking attacks. Observations were made of Kittiwake nests using four years of archival film footage of a Lundy population. Beak grabbing was used as a specific measure of attempts to gain food from parents, as opposed to the more general begging label used in previous studies. Results found that beta chicks were only very rarely pecked when they performed the beak grab behaviour. Beta chicks were also found to use appeasement strategies in combination with food gaining behaviours. Pecking attacks did not follow where these motions were employed. Results of this study are discussed in terms of the functions of the behaviours displayed

Locality and topology in the molecular Aharonov-Bohm effect

It is shown that the molecular Aharonov-Bohm effect is neither nonlocal nor topological in the sense of the standard magnetic Aharonov-Bohm effect. It is further argued that there is a close relationship between the molecular Aharonov-Bohm effect and the Aharonov-Casher effect for an electrically neutral spin$-{1/2}$ particle encircling a line of charge.Comment: 3 pages, no figure

Push clocks: a new approach to charge-coupled devices clocking

A new approach to charge-coupled device clocking has been developed—dynamic push clocks. With dynamic push clocks, the charge is transferred by pushing it from one storage site to another. The push clock approach results in a larger signal dynamic range, larger signal-to-noise ratio, and better performance at both high and low frequencies

Performance of carrot and onion seed primed with beneficial microorganisms in glasshouse and field trials

Beneficial microorganisms (Clonostachys rosea IK726, Pseudomonas chlororaphis MA342, Pseudomonas fluorescens CHA0, Trichoderma harzianum T22 and Trichoderma viride S17a) were successfully applied to carrot and onion seed during a commercial drum priming process. Applied microorganisms were recovered above the target of at least 1 × 105 cfu g−1 seed following subsequent application of pesticides to the seed according to standard commercial practices of film-coating carrot and pelletting onion seed. Two glasshouse experiments consistently showed that priming improved emergence of carrot seed and that C. rosea IK726 further improved emergence time. Priming improved emergence of onion seed in one glasshouse experiment, but had an unexpected negative effect on emergence in the second experiment, possibly due to the proliferation of an unidentified indigenous microorganism during priming, becoming deleterious in high numbers. In this experiment, the application of beneficial microorganisms during priming negated this effect and significantly improved emergence. For each crop, a series of field trials was also carried out over three years, at two different sites each year. Although some positive effects of different seed treatments were seen on emergence or yield in individual field trials, no consistent effects were found for primed or microorganism-treated seed across all sites and years. However, a combined analysis of data for all years and sites indicated that pesticide application did consistently improve emergence and yield for both carrot and onion. This is the first comprehensive study assessing glasshouse and field performance of carrot and onion seed primed with beneficial microorganisms during a commercial process of drum priming in the UK

Function generator eliminates necessity of series summation

Diode generator using four building-block circuits produces complex waveforms without the necessity of series summation. This highly specialized method of producing complex waveforms requires less power than present methods and uses simpler circuitry

Impact Ionization and Hot-Electron Injection Derived Consistently from Boltzmann Transport

We develop a quantitative model of the impact-ionizationand hot-electron–injection processes in MOS devices from first principles. We begin by modeling hot-electron transport in the drain-to-channel depletion region using the spatially varying Boltzmann transport equation, and we analytically find a self consistent distribution function in a two step process. From the electron distribution function, we calculate the probabilities of impact ionization and hot-electron injection as functions of channel current, drain voltage, and floating-gate voltage. We compare our analytical model results to measurements in long-channel devices. The model simultaneously fits both the hot-electron- injection and impact-ionization data. These analytical results yield an energydependent impact-ionization collision rate that is consistent with numerically calculated collision rates reported in the literature